Bioactive Potential of Aqueous Phenolic Extracts of Spices for Their Use in the Food Industry—A Systematic Review

Citation: Duque-Soto, C.; Ruiz-Vargas, A.; Rueda-Robles, A.; Quirantes-Piné, R.; Borrás-Linares, I.; Lozano-Sánchez, J. Bioactive Potential of Aqueous Phenolic Extracts of Spices for Their Use in the Food Industry—A Systematic Review. Foods 2023,12, 3031. https://doi.org/10.3390/ foods12163031 Academic Editor: Hong Wu Received: 20 July 2023 Revised: 8 August 2023 Accepted: 10 August 2023 Published: 12 August 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). foods Review Bioactive Potential of Aqueous Phenolic Extracts of Spices for Their Use in the Food Industry—A Systematic Review Carmen Duque-Soto 1, Ana Ruiz-Vargas 1, Ascensión Rueda-Robles 1, Rosa Quirantes-Piné2, Isabel Borrás-Linares 3,* and Jesús Lozano-Sánchez 1 1Department of Food Science and Nutrition, University of Granada, Campus Universitario s/n, 18071 Granada, Spain; [email protected] (C.D.-S.); [email protected].es (A.R.-V.); [email protected] (A.R.-R.); [email protected] (J.L.-S.) 2 Research and Development Functional Food Centre (CIDAF), Health Science Technological Park, Avenida del Conocimiento 37, Edificio BioRegión, 18016 Granada, Spain; [email protected] 3Department of Analytical Chemistry, Faculty of Sciences, University of Granada, 18071 Granada, Spain *Correspondence: [email protected] Abstract: The interest on the use of natural sources in the food industry has promoted the study of plants’ phenolic compounds as potential additives. However, the literature has been focusing on essential oils, with very few studies published regarding aqueous extracts, their phenolic composition, and bioactivity. A systematic review was conducted on different databases following PRISMA guidelines to evaluate the relevance of the phenolic content of different aromatic spices (oregano, rosemary, thyme, ginger, clove, and pepper), as related to their bioactivity and potential application as food additives. Although different extraction methods have been applied in the literature, the use of green approaches using ethanol and deep eutectic solvents has increased, leading to the development of products more apt for human consumption. The studied plants present an interesting phenolic profile, ranging from phenolic acids to flavonoids, establishing a correlation between their phenolic content and bioactivity. In this sense, results have proven to be very promising, presenting those extracts as having similar if not higher bioactivity than synthetic additives already in use, with associated health concerns. Nevertheless, the study of spices’ phenolic extracts is somehow limited to in vitro studies. Therefore, research in food matrices is needed for more understanding of factors interfering with their preservation activity. Keywords: phenolic compounds; plant extracts; medicinal and aromatic plants; antioxidant activity; antimicrobial activity; green extraction 1. Introduction The production of millions of tons of residues every year as a result of a modern lifestyle and its impact on the environment has become a rising public worry. In response, society has focused on the development of more sustainable and healthy approaches. Thus, the use of natural agro-food by-products as sources in the industry has been promoted as a great alternative to currently used raw materials [ 1 ]. This has also transpired into the food industry, where consumers seem to increasingly prefer more natural additives as opposed to their synthetic counterparts, influenced by the recent concerns about their health safety. Medicinal and aromatic plants (MAPs) have been historically used for traditional medicine and pose as an interesting source of bioactive compounds, with proven antioxidant and antimicrobial activities [ 2 ]. Therefore, they can potentially be used in the food industry for the delay or prevention of food quality loss caused by microbial growth and undesirable chemical reactions [3]. Some of the most renowned MAPs are spices, many of which have been recognized as safe for human consumption, such as oregano, parsley, rosemary, or thyme. They are mainly used in food preparations as flavourings and as alternatives for salt consumption Foods 2023,12, 3031. https://doi.org/10.3390/foods12163031 https://www.mdpi.com/journal/foods Foods 2023,12, 3031 2 of 23 for people with high blood pressure [ 4 ]. Additionally, their consumption has been related to protection against cardiovascular diseases, neurodegeneration, type II diabetes, and cancer [5]. Spices have already been used as raw materials for a variety of industries (including cosmetic, pharmacological, and food industries) as flavourings, food colourings, essential oils, sweeteners, or even for their nutraceutical activities, mainly due to their phenolic composition [ 6 – 8 ]. Along with the increasing interest for the consumption of more natural and environmentally friendly foods, spices are gaining a newfound interest for their innovative use as a source for these natural bioactive compounds [9]. Phenolic compounds are plant secondary metabolites consisting of an aromatic ring with one or more hydroxyl groups and can be synthesized using the shikimic acid or acetate pathway [ 10 ]. More than 8000 phenolic compounds have been described in MAPs, which are commonly classified as phenolic acids, flavonoids, stilbenes, and lignans [ 11 ]. In this regard, the most popular characterization technique has been high-performance liquid chromatography (HPLC), although the Folin–Ciocalteu method has also been used to determine total phenolic compounds. It must be considered that bioactive compounds can be lipophilic, such as essential oils, oleoresins, curcuminoids, and carotenoids that are extracted using non-polar solvents, or hydrophilic, such as many polyphenols that are extracted using more polar solvents [ 12 ]. As well-known important sources of phenolic compounds and profoundly reviewed in the previous literature, essential oils have been widely studied as additives for food preservation [ 13 , 14 ]. However, the inherent characteristics of essential oils constrain their composition primarily to the least polar polyphenols, which are also present in relatively low concentrations. This circumstance could potentially limit their practical utility. In contrast, the use of aqueous-based extracts rich in more polar phenolic compounds, which appear in higher concentrations, is, therefore, very promising. Phenolic compounds are known for their antioxidant and antimicrobial activity, which have sustained their interest in the food industry [ 15 – 17 ]. The bioactivity of phenols is an interesting topic for their use as food preservatives. Its potential mainly depends on their content and distribution in the plant, which is affected by factors prevailing during the cultivation of plants, such as the weather, type of soil, type of crop, and sun exposure, among others [ 18 ]. The addition of these compounds to the packaging for antimicrobial protection has already been studied in various forms: (a) in special structures containing them, (b) either in their volatile or non-volatile form, as polymers, (c) as polymer coating, (d) bound through ionic or covalent bonds, or (e) intrinsically in the packaging. In a similar way, for their control of lipid and pigment oxidation, they have been studied in foods as (a) an edible coating or (b) freed on its surface [ 19 ]. With the intention of extracting and concentrating these compounds, implementation of both conventional and more advanced extraction techniques have been studied [18]. As far as we know, this is the first review regarding the comparison of the extraction techniques available and the evaluation of the most recent methods, focused on a more environmentally friendly and safer approach to human consumption, as well as a study of their phenolic content as related to their bioactivity and potential use, as essential aspects into their legal consideration as additives [ 20 ]. As previously started, the study of phenolic compounds from spices has been focused on their essential oils. For this reason, even though they present great potential as sources of more polar and abundant compounds, aqueous phenolic extracts have not been considered until recently, as their phenolic characterization is rather scarce. Also, there is a dire need to evaluate the effect that different extraction methods and conditions could have on the chemical composition of extracts and its relevance to its potential synergistic bioactivity. Additionally, previous evidence of their bioactivity and safety for application in food products is needed in order to enable their legal use in the industry, as stated by current legislation and mediated by official organizations, such as the European Food Safety Authority (EFSA) and the Food and Drug Administration (FDA) [20]. Foods 2023,12, 3031 3 of 23 The aim of this systematic review is to evaluate the evidence regarding the preservative activity of phenolic compounds from MAPs extracts, such as oregano ( Origanum vulgare , Origanum glandulosum), rosemary (Rosmarinus officinalis L.), thyme (Thymus zygis gracilis, Thymus membranaceus, Thymus longiflorus), ginger (Zingiber officinale), clove (Eugenia caryophyllata), and pepper (Piper nigrum), which may promote their use in the food industry. This main objective can be divided into the following sub-objectives: (1) determining phenolic compounds content in plant extracts; (2) analyzing antioxidant activity of polyphenol-rich extracts; and (3) studying antimicrobial activity of those extracts. 2. Materials and Methods 2.1. Search Strategy Systematic research was conducted following PRISMA guidelines. PubMed and Scopus databases were searched to select papers, including the phenolic composition of extracts and their bioactivity in in vitro and food-applied studies. This review focuses on systematic reviews, meta-analyses, and randomized controlled studies published in the years 2001–2022 . No language filter was applied. Exclusion criteria were: (1) restricted access articles, (2) non-relation to the subject of study, and (3) articles focused on spices’ essential oils. In addition, the PICO process was followed using the following parameters: (1) Population: in vitro analysis; (2) Intervention: antioxidant and antimicrobial activity; (3) Comparison: human food; and (4) Outcome: aromatic plants’ use with the technological function being possible, sustainable, and innovative. As for eligibility criteria, articles not focused on the subject of interest were excluded from the analysis, including articles evaluating essential oils and those that did not include the selected plant families. The study selection process is shown in Figure 1. Foods 2023, 12, x FOR PEER REVIEW 3 of 23 to enable their legal use in the industry, as stated by current legislation and mediated by official organizations, such as the European Food Safety Authority (EFSA) and the Food and Drug Administration (FDA) [20]. The aim of this systematic review is to evaluate the evidence regarding the preservative activity of phenolic compounds from MAPs extracts, such as oregano (Origanum vulgare, Origanum glandulosum), rosemary (Rosmarinus officinalis L.), thyme (Thymus zygis gracilis, Thymus membranaceus, Thymus longiflorus), ginger (Zingiber officinale), clove (Eugenia caryophyllata), and pepper (Piper nigrum), which may promote their use in the food industry This main objective can be divided into the following sub-objectives: (1) determining phenolic compounds content in plant extracts; (2) analyzing antioxidant activity of polyphenol-rich extracts; and (3) studying antimicrobial activity of those extracts. 2. Materials and Methods 2.1. Search Strategy Systematic research was conducted following PRISMA guidelines. PubMed and Scopus databases were searched to select papers, including the phenolic composition of extracts and their bioactivity in in vitro and food-applied studies. This review focuses on systematic reviews, meta-analyses, and randomized controlled studies published in the years 2001–2022. No language filter was applied. Exclusion criteria were: (1) restricted access articles, (2) non-relation to the subject of study, and (3) articles focused on spices’ essential oils. In addition, the PICO process was followed using the following parameters: (1) Population: in vitro analysis; (2) Intervention: antioxidant and antimicrobial activity; (3) Comparison: human food; and (4) Outcome: aromatic plants’ use with the technological function being possible, sustainable, and innovative. As for eligibility criteria, articles not focused on the subject of interest were excluded from the analysis, including articles evaluating essential oils and those that did not include the selected plant families. The study selection process is shown in Figure 1. Figure 1. PRISMA scheme with articles included in the present systematic review. Figure 1. PRISMA scheme with articles included in the present systematic review. 2.2. Search Formulas and Keywords The search formulas and keywords used in the present systematic review have varied depending on the interest at hand: (a) For phenolic compounds: (Herbs OR Spices OR Foods 2023,12, 3031 4 of 23 Aromatic plants OR plant extract) AND (Phenol compounds OR polyphenols OR bioactive compounds) AND (Extraction methods OR extraction OR characterization methods) AND (green extraction OR alternative technologies); (b) For antioxidant activity: (Herbs OR Spices OR Aromatic plants OR plant extract) AND (Phenol compounds OR polyphenols OR bioactive compounds) AND (Antioxidants OR Natural antioxidants) AND (Oregano OR Origanum OR Thyme OR Thymus serpyllum OR Thymus plant OR Rosemary OR Ginger OR Clove OR Pepper); (c) For antimicrobial activity: (Herbs OR Spices OR plant extract) AND (Phenol compounds OR polyphenols OR bioactive compounds) AND (Antimicrobial OR Antiviral) AND (Food-preservation OR Food safety). 3. Results and Discussion 3.1. Main Phenolic Compounds Identified in Medicinal and Aromatic Plants In this review, the most prominent phenolic characterization studies and extraction techniques have been compiled. The selection of a specific method and extraction technique has depended on the physico-chemical nature of the compounds to be extracted, its cost, and security. The factors that influence the extraction efficiency are the chemical nature of the extraction solvent, the particle size of the plant materials, the solvent–solid ratio, temperature, and extraction time. Additionally, extract storage conditions have influenced its shelf life and bioactivity [2]. Extraction techniques applied in the literature have been (a) conventional techniques; (b) pressurized liquid extraction, as supercritical fluids (PLE), subcritical fluids (SFE), and accelerated solvents; (c) microwave-assisted extraction (MAE); or (d) ultrasound-assisted extraction (UAE). However, microwaveand ultrasound-assisted extraction have been the most widely used techniques for bioactive compounds. The latter allows the extraction of stronger flavors and their preservation for a longer time [ 21 ]. In addition, its non-thermal nature allows a lower negative effect on basic physical and chemical parameters, such as total acid, total soluble solid, color, electrical conductivity, viscosity, and density [22]. Although a multitude of solvents from glycerol to choline chloride have been applied, the highest performing and, therefore, most used are ethanol and methanol. This has been observed in Bellumori et al. (2016), where the use of ethanol and acetone as extraction solvents in ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) improved the extraction yield of phenolic compounds, obtaining better results than when a double ethanol maceration as solid–liquid extraction processes was applied [23]. The importance of the selected solvent can be further observed in Proestos and Komaitis (2006), where ultrasonically assisted extraction using water as a solvent reduced the amounts of phenolic compounds as compared to the conventional method [ 24 ]. Different extraction solvents were compared: 60% methanol, 60% acetone, water, and ethyl acetate/water (60:30, v/v), with methanol being the best option for extracting phenolic compounds from plant tissues. These results were in line with those previously published by Wang, Provan, and Helliwell (2004) [ 25 ]. In this study, ethanol, methanol, acetone, and acetonitrile, all at 30% in water (v/v), were evaluated for the extraction of rosmarinic and caffeic acids and compared with the extraction using water as the selected solvent. Extraction was similar when using ethanol, methanol, acetonitrile, or acetone. However, rosmarinic acid content was 20% lower when compared with the extraction using water as a solvent. This has also been observed in Bellumori et al. (2016), where a low extraction of total phenolic content (TPC) was reported when water was used as a solvent [ 23 ]. Additionally, the efficiency of methanol and ethanol as extraction solvents was confirmed in Švarc-Gaji´c et al. (2013), where 70% methanol provided the highest yield of TPC with MAE, while flavonoids were extracted more efficiently in the microwave field using 70% ethanol [ 26 ]. However, an assessment of different extraction solvents has been restricted to specific studies and, while it would be ideal to evaluate this effect through the literature, differences in the experimental conditions applied for each extraction technique and the evaluated spice between studies do not allow for this comparison to be carried out. Foods 2023,12, 3031 5 of 23 Also, the use of a combination of emerging technologies has presented a great potential for higher extraction than using these individual techniques [ 27 ]. This has been observed in Tzima et al. (2021) where Pulsed Electric Field was used as a pre-treatment step for improving the obtention of phenolic compounds using UAE [ 28 ]. This effect was explained through an increase in solubility of phenolic compounds and facilitated permeability through plant cell walls, facilitating enhanced recovery of ultrasound-extracted bioactive compounds. Even though the aforementioned methods provide good extraction results, their adequacy for the implementation in food products must be addressed. In this sense, the development of the so-called green methods has taken interest, not only as more environmentally friendly approaches but also as more suitable for their later purpose. Regarding green methods for the extraction of bioactive compounds, one of the most popular is the use of deep eutectic solvents (DES). In Barbieri et al. (2020), combinations of glycerol:choline chloride (1:2 v/w) and water (10% w/w), lactic acid:choline chloride (1:3 v/w) and water (10% w/w), 1,2-propanediol:choline chloride (1:2 v/w) and water (10% w/w) , and oxalic acid:choline chloride (1:1 v/w) and water (10% w/w) were used and compared with ethanol as a solvent [ 29 ]. In this case, the combination of solvents showed a higher antioxidant capacity than the alcoholic extract, measured with the 2,2diphenyl-1-picrilhydrazil oxide depletion (DPPH) and ferric-reducing antioxidant capacity (FRAP) assays. In addition, ethanolic extract presented the lowest stabilizing ability of the phenolic compounds present in the extract. Overall, these promising results propose the use of GRAS (generally recognized as safe by the FDA) solvents as great alternatives for the obtention of enhanced extracts in the food industry. Regarding the plant material, phenolic compounds can be extracted from multiple parts of the aromatic plant, such as flowers, leaves, or seeds. However, as phenolic content seems to vary between different plant structures, flower extracts seem to generally present the highest presence of polyphenols [ 30 ]. However, other structures have also been used. In the analyzed studies, rosemary polyphenols were extracted from leaves [ 29 , 31 ] and branches [ 32 ]. Oregano phenolic extracts were mainly obtained from leaves [ 32 ]. As for thyme, extracts were obtained either from the leaves [ 31 , 33 , 34 ] or the leaves and branches [ 32 ]. Rosemary extracts were obtained from the rhizome area [ 35 , 36 ] and, in the case of cloves, from flowers [ 33 ]. The rest of the studies do not indicate the part of the aromatic plant from which the extracts were obtained. As for characterization methods, the most used among the literature were HPLC and the Folin–Ciocalteu method [ 23 , 26 , 30 , 33 , 36 – 48 ]. The combination of the former coupled with the mass spectrometry has also been widely used as an analytical characterization method. Among HPLC, normal phase (NP-HPLC), reverse phase (RP-HPLC), and hydrophilic interaction liquid chromatography (HILIC-HPLC) have also been used [49]. Throughout different studies, regardless of the extraction method, the phenolic profile of spices seems to be comparable. Main phenolic compounds characterized in different spices can be found in Table 1. The main phenolic compounds identified in the different species of oregano were similar, although variations in their content may be present. Some of the main phenolic compounds identified in this spice belonged to phenolic acids, such as rosmarinic acid, caffeic acid, gallic acid, p-coumaric acid, chlorogenic acid, and ferulic acid [ 24 , 36 , 38 , 43 , 48 ]. Structures of the most relevant phenolic compounds found in the spices are presented in Figure 2. The mentioned acids are widely known for their great antioxidant activity. The presence of flavonoids, such as apigenin, luteolin and quercetin, should also be noted [24,38,48]. Foods 2023,12, 3031 6 of 23 Table 1. Phenolic compounds characterized in different spices. Spice Extract Phenolic Compound Extraction Technique Extraction Conditions Characterization Technique References Oregano Glycosylated flavonoids: kaempferol-O-glucuronide and luteolin-7-O glucuronide. MAE. 100% water, 42 ◦C and 2 min. extraction time. Folin–Ciocalteu. [38] Rosmarinic, caffeic, chlorogenic, ferulic, gallic, p-coumaric, syringic and vanillic acids. Dynamic sonication assisted ethanol extraction. 60% ethanol (v/v) at room temperature, 0.25 h. LC ×LC-MS. [48] Caffeic and caffeic-O-hexoside, protocatechic, rosmarinic, 3-, 4and 5-O-caffeoylquinic, coumaroylquinic, ferulic-O-hexoside, ferulic, p-coumaric, homovanillic-O-hexoside, gallic acids, syringic, pand m-hydroxybenzoic, kaempferol-3-O-glucoside, kaempferol, and quercetin. SPE. Hydroalcoholic solvent. Folin–Ciocalteu, HPLC LTQ-Orbitrap mass spectrometry. [43] Gallic acid, caffeic acid, gentisic acid, p-coumaric acid, vannyl acid, ferulic acid, syringic acid, catechin, rutin, quercetin, apigenin, naringenin, and eriodictyol UAE. 60% methanol, 60% acetone, water and ethyl acetate/water [60:30, v/v]. RP-HPLC and Folin–Ciocalteu. [24] Rosemary Carnosoic acid and rosmarinic acid. SFE. 40 ◦C and 300 bar. GC-FID, TLC [32] Rosmarinic acid, caffeine, 7-methylrosmanol, rutin, naringin, and ferulic acid. UAE. Glicerol:choline chloride (1: 2 v/w) and water (10% w/w), lactic acid:choline chloride (1:3 v/w) and water (10% w/w), 1,2-propanediol:choline chloride (1:2 v/w) and water (10% w/w): deep eutectic solvents compared to pure ethanol. Folin—Ciocalteu. [29] Phenolic acids (gallic acid, rosmarinic acid, p-coumaric acid), flavonoids (quercetin 3-O-galactoside, kaempferol 3-O-glucuronide), and terpenoids (rosmanol, carnosol, carnosic acid). UAE and CE. 100% water and 50:50 ethanol:water. Folin–Ciocalteu and Triple TOF-LC-MS-MS. [37] Flavonoids (cirsimaritin, genkwanin), rosmarinic acid and terpenoids (rosmanol, carnosol, carnosic acid). UAE and MAE. UAE: 140 W MAE: N220 bar, 100 ◦C. HPLC-DAD-MS-TOF. [23] Total polyphenols, flavonoids, anthocyanins, monomeric and condensed anthocyanins. MAE. Methanol: water (70:30, v/v), 70 ◦C. Folin–Ciocalteu. [26] Flavonoids (luteolin, apigenin, diosmetin, cirsimaritin, genkwanin) and terpenoids (rosmanol, carnosol, carnosic acid). SFE and PLE. SFE: 150 bar 6.6% ethanol and 400 bar with CO 2 , 40 ◦ C. PLE: ethanol 150 ◦ C and water 100 ◦C and 200 ◦C, 20 min. HPLC-DAD-MS. [45] Caffeic and caffeic-O-hexoside, protocatechic, rosmarinic, 3-, 4and 5-O-caffeoylquinic, coumaroylquinic, ferulic-O-hexoside, ferulic, p-coumaric, homovanillic-O-hexoside, gallic acids, syringic, pand m-hydroxybenzoic, kaempferol-3-O-glucoside, kaempferol, and quercetin. SPE. Hydroalcoholic solvent. Folin–Ciocalteu. HPLC + LTQ-Orbitrap mass spectrometry. [43] Foods 2023,12, 3031 7 of 23 Table 1. Cont. Spice Extract Phenolic Compound Extraction Technique Extraction Conditions Characterization Technique References Thyme Derivatives of hydroxycinnamic acid: caffeic acid hexoside, rosmarinic acid and derivatives of salvianolic acid-A. Glycosylated flavonoids: luteolin-7-O-glucuronide and kaempferol-O glucuronide. MAE. 150 ◦C, 50% ethanol and 9.5 min. Folin–Ciocalteu. [38] Rosmarenic acid, methyl rosmarnate, caffeic acid, cinnamic acid, chlorogenic acid, quinic acid, and flavonoids such as ferulic acid, apigenin, luteolin, and quercetin. Maceration. Metanol, ethanol, diethyl ether and hexane, 72 h. Folin–Ciocalteu and HPLC. [34] Caffeic and caffeic-O-hexoside, protocatechic, rosmarinic, 3-, 4and 5-O-caffeoylquinic, coumaroylquinic, ferulic-O-hexoside, ferulic, p-coumaric, homovanillic-O-hexoside, gallic acids, syringic, pand m-hydroxybenzoic, kaempferol-3-O-glucoside, kaempferol, and quercetin. SPE. Hydroalcoholic solvent. Folin–Ciocalteu. HPLC + LTQ-Orbitrap mass spectrometry. [43] p-coumarinic acid, kaempferol, epigenin, ferulic acid, luteolin, rosmarinic acid, gallic acid, epigenin, eugenol, quercetin. UAE and CE. Water 100% and 50:50 ethanol:water. Folin–Ciocalteu and Triple TOF-LC-MS-MS. [37] Ginger Total soluble solids, total polyphenols, flavonoids and non-flavonoids, total carotenoids, and vitamin C. UAE. Water as solvent, 40–70 ◦C and 30 min Folin–Ciocalteu. [22] Pepper Capsaicinoids (nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin). UAE. Methanol as solvent, 50 ◦C and 10 min. HPLC-fluoresncence. [44] Piperine and piperine acid, anisic acid, methyl anisate, shikimic acid, methyl shikimate. Oxidative or steam distilled. Piperine extraction: Ethanol, 80 ◦C, 2 h. Piperine acid extraction: Piperine dissolved in KOH/ethanol at 1 /4(v/v), at 8◦C, 15 h. 1H NMR, 13C NMR, FTIR, and HPLC. [50] Clove Tannins, phenolic compounds, terpenoids, glycosides. cardiac. TPC (mg/g): Kaempeforl 5.839, Catechin 0.0184, Gallic acid 0.0169. Maceration. 80% ethanol at a ratio of 1:5 (w:v) 24 h. GC-MS and HPLC-DAD. [40] DPPH: diphenyl picril hydrazyl; HPLC: high-performance liquid chromatography; MAE: microwave-assisted extraction; MS: mass spectrometry; SFE: supercritical fluid extraction; SPE: solid-phase extraction; TLC: thin-layer chromatography; TOF: time-of-flight mass spectrometry; UAE: ultrasound-assisted extraction. Foods 2023,12, 3031 8 of 23 Foods 2023, 12, x FOR PEER REVIEW 8 of 23 Figure 2. Most relevant phenolic compounds in different spices. Rosemary extracts were the most studied in terms of optimization of the extraction process and characterization of bioactive components, which could be related to their industrial use. This is also observed for thyme and oregano, widely studied in comparison to other spices, such as cloves and ginger, from which no significant results have been found. The main phenolic compounds identified in rosemary were carnosoic acid and rosmarinic acid. Extracts of this spice contain flavonoids, like catechin, quercetin, rutin, naringin, and kaempferol, and phenolic acids, like chlorogenic acid, p-hidroxibenzoic acid, and protocatechuic acid [23,32,33,42]. Thyme extracts presented rosmarinic acid, caffeic acid, cinnamic acid, chlorogenic acid, and ferulic acid, among other compounds [34,37,38,43]. The main flavonoids contained were apigenin, luteonin, and quercetin. Phenolic content has been abundantly quantified using the Folin–Ciocalteu method, but there is not much information about the quantification of individual phenolic compounds, as well as a lack in general characterization of this genus [38]. As for pepper, its main phenolic compounds were capsaicinoids, such as nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin [44,50]. These bioactive compounds were extracted using ultrasound using methanol as the extractant solvent and characterized using HPLC with fluorescence detection and monolithic columns for separation [44]. It is important to note that since studies evaluating different solvents found no differences between ethanol and methanol, ethanol should be preferably selected for food applications due to its GRAS solvent status. For its application in the industry, suitability of these extracts for human consumption needs to be considered. All substances isolated in the considered extracts and most solvents used for their extraction in the considered studies are GRAS substances and, thus, initially considered as innocuous, making them a good alternative to chemical additives normally used in the food industry. Figure 2. Most relevant phenolic compounds in different spices. Rosemary extracts were the most studied in terms of optimization of the extraction process and characterization of bioactive components, which could be related to their industrial use. This is also observed for thyme and oregano, widely studied in comparison to other spices, such as cloves and ginger, from which no significant results have been found. The main phenolic compounds identified in rosemary were carnosoic acid and rosmarinic acid. Extracts of this spice contain flavonoids, like catechin, quercetin, rutin, naringin, and kaempferol, and phenolic acids, like chlorogenic acid, p-hidroxibenzoic acid, and protocatechuic acid [23,32,33,42]. Thyme extracts presented rosmarinic acid, caffeic acid, cinnamic acid, chlorogenic acid, and ferulic acid, among other compounds [ 34 , 37 , 38 , 43 ]. The main flavonoids contained were apigenin, luteonin, and quercetin. Phenolic content has been abundantly quantified using the Folin–Ciocalteu method, but there is not much information about the quantification of individual phenolic compounds, as well as a lack in general characterization of this genus [38]. As for pepper, its main phenolic compounds were capsaicinoids, such as nordihydrocapsaicin, capsaicin, dihydrocapsaicin, homocapsaicin, and homodihydrocapsaicin [ 44 , 50 ]. These bioactive compounds were extracted using ultrasound using methanol as the extractant solvent and characterized using HPLC with fluorescence detection and monolithic columns for separation [44]. It is important to note that since studies evaluating different solvents found no differences between ethanol and methanol, ethanol should be preferably selected for food applications due to its GRAS solvent status. For its application in the industry, suitability of these extracts for human consumption needs to be considered. All substances isolated in the considered extracts and most solvents used for their extraction in the considered studies are GRAS substances and, thus, initially considered as innocuous, making them a good alternative to chemical additives normally used in the food industry. 3.2. Antioxidant Capacity Analysis in Spices 3.2.1. Main Antioxidant Methods Applied to Aromatic Plants An abundance of antioxidant activity assays has been applied on spices in the literature. These methods can be based on hydrogen atom transfer, such as Oxygen Radical Foods 2023,12, 3031 9 of 23 Absorbance Capacity (ORAC) or Total Radical-Trapping Antioxidant Parameter (TRAP); electron transfer, such as FRAP; or in a mix of both phenomena, such as depletion of 2,2’-Azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) or DPPH. In order to measure the antioxidant activity of extracts accurately, choosing an adequate assay based on the chemicals of interest and, above all, the food matrix in which it will be included are critical. ABTS and DPPH assays seem to be the most used radical scavenging assays for spices [ 30 , 36 , 38 , 41 , 43 , 51 , 52 ]. This can be related to the convenience and adequacy of these methods to a variety of conditions, as well as their benefits. DPPH stands out as a fast, simple, and inexpensive assay, with few steps and reagents needed, as well as with a high repeatability. Some disadvantages may be the use of organic solvents, their sensitivity to pH, and color interference that could cause underestimation of results [53]. On the other hand, ABTS can be applied to either lipophilic or hydrophilic samples, with high reproducibility, which makes it a highly versatile assay. This method may also have some disadvantages, such as its sensitivity to light and temperature or lack of standardization, which makes it difficult to compare in interlaboratory studies [53]. Even though relatively less is used, ORAC, TRAP, and FRAP have also been described in the literature. As for ORAC, its relevance for the study of biologically relevant free radicals as well as the use of various free radical generators can be interesting, but results cannot be expressed in weight, hindering interstudy comparisons. On another note, TRAP may be suitable for studying activity against potent antioxidants (such as hydroxyl and peroxyl radicals). Lastly, FRAP must also be considered as an easy and inexpensive assay, although instability of oxygen electrodes, the use of low pH, or the lack of detection of SH-group antioxidants may cause some disadvantages [53–55]. However, a combination of a few assays must be carried out to have a realistic assessment of the antioxidant capacity of a sample. Moreover, the difference in nature between some of the assays as well as the expression of the results based on different standards can hinder the comparison of different results and studies. 3.2.2. Antioxidant Activity and Main Phenolic Compounds Identified in Aromatic Plants As has been established in the literature, the antioxidant activity of medicinal and aromatic plants shows great potential for their use in the food industry, which is evidence for their acceptance as food additives. In this sense, antioxidant potential of medicinal and aromatic plants has been studied through their phenolic composition, as main contributors to this activity, as presented in Tables 1and 2. Phenolic content of extracts of multiple MAPs obtained through different extraction procedures has been evaluated, as is the case for Lamiaceae plants, such as oregano, rosemary, and thyme. Additionally, several studies have considered their application on a variety of food matrices. Antioxidant potential of oregano has been evaluated in extracts and applied on different food matrices through ABTS and DPPH methods [ 36 , 38 , 43 ]. As for extraction conditions for phenolic recovery, MAE appears to be one of the main techniques. In Nabet et al. (2019), MAE phenolic extracts from O. glandulosum showed good antioxidant potential [ 38 ]. When phenolic compounds were extracted with MAE, lower concentrations of ethanol resulted in greater recovery of compounds and enhanced antioxidant activity. Studies on other species of oregano (O. vulgare) presented similar consistent high-antioxidant results [ 36 , 43 ]. Nevertheless, the main phenolic composition appears to be similar throughout the studies, though total content may vary. Many of the identified compounds belong to phenolic acids, such as caffeic or rosmarinic (known for its great antioxidant capacity) as well as flavonoids, such as quercetin, apigenin, and kaempherol, mainly in its glycosylated forms. Foods 2023,12, 3031 16 of 23 as a natural antimicrobial. Water and ethanol as solvents were compared, showing that a rosemary ethanolic extract exhibited an inhibitory effect against four pathogenic bacteria strains (Escherichia coli, Salmonella enteritidis, Bacillus cereus, and Staphylococcus aureus) while the aqueous extract was only effective against three strains (Escherichia coli, Bacillus cereus, and Staphylococcus aureus). However, the highest MIC values (% w/v) were obtained from water-obtained extracts [31]. In Çelik et al. (2021), the antimicrobial activity of thyme extracts was evaluated through MIC values in Muller–Hillton agar using the agar-well diffusion method [ 56 ]. The assayed extract achieved inhibition of Bacillus cereus 702 Roma and Mycobacterium smegmatis ATCC607. In Bouymajane et al. (2022), antimicrobial assays were carried out using the microdilution method in tryptone soy yeast to evaluate the minimal inhibition concentration and minimal bactericidal concentration (MIC and MBC) [ 67 ]. Thus, Thymus zygis gracillis presented an antimicrobial effect on Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Listeria monocytogenes, Enterococcus faecalis, and Staphylococcus aureus. Another thyme extract was evaluated in Mascoloti et al. (2022), where extracts were able to inhibit the growth of Escherichia coli, Salmonella typhimurium, Enterobacter cloacae, Staphylococcus aureus, Bacillus cereus, and Listeria monocytogenes [68]. Ginger extracts have proved to inhibit the proliferation of different bacteria, fungi, and viruses in the previous literature. These effects could be mainly related to the suppression of bacterial biofilm formation, ergosterol biosynthesis, and viral adhesion and internalization [ 69 ]. In Chang, Wang, Yeh, Shieh, and Chiang (2013), the antimicrobial capacity of Zingiber officinale Roscoe against human respiratory syncytial virus (HRSV) was studied using ELISA, where ginger was able to decrease the virus proliferation in respiratory mucosa cell lines [ 71 ]. In Zhong et al. (2021), the antimicrobial capacity of different fractions of ethanolic extracts were evaluated in comparison to essential oils [ 73 ]. Fractions were obtained by a combination of different aqueous ethanolic extracts evaporated and redissolved in water-saturated EtOAc. The EtOAc soluble fraction of ethanolic extracts presented significant antibacterial activity, while the insoluble fraction was inactive. Then, the extract was fractionated via silica gel column chromatography into eight parts according to their polarities to study them separately (fractions M1–M8). M1-M4 fractions showed potential to suppress the growth of B. subtilis while M3 presented the lower MIC value (1 µ g/mL), and M2 showed higher inhibition with a MIC value of 8 µ g/mL against the same bacteria. Fractions M5-M8 were inactive at a concentration of 128 µ g/mL against all bacteria tested. Among the four active fractions (M1–M4), M3 showed the highest efficacy against the tested microorganisms. This high antibacterial activity could be related to its great content in bioactive components. Clove extracts have also been studied for their antimicrobial potential. In this regard, Mostafa et al. (2018) evaluated different ethanolic plant extracts against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhi [ 35 ]. Among the extracts considered, clove ethanolic extract, along with Punica granatum, showed the best antimicrobial activity in fish-derived products. Additionally, their antimicrobial properties are further demonstrated in Rosarior et al. (2021), where clove extracts showed an in vitro antimicrobial effect against urinary tract infections (UTI) caused by Proteus mirabilis and Staphylococcus epidermidis [ 40 ]. This bioactivity has been exceptional for their aqueous extracts. At the same concentration of eugenol, the clove extract showed better antioxidant and antimicrobial capacity than its respective essential oil. This could be related to differences in phenolic content, as essential oils tend to present more apolar molecules as well as a lower concentration. Overall, it could be considered that their antimicrobial activity depends on the bioactive compound concentration: when it is low, phenolic compounds inhibit microbial enzyme activity, whereas at high concentrations, they induce denaturation of proteins. The nature of functional groups present in these compounds should also be considered, as it varies between different phenolics. For example, hydroxyl groups could cause the decay of a proton motive force, depletion of an ATP pool, and consequently, cell death [74]. Foods 2023,12, 3031 17 of 23 As observed, this bioactivity places the studied extracts as potential additives for food products. Moreover, these properties could also be considered for their use in food packaging. Once pathogens adhere to the food surface and form biofilms, their removal is difficult. Therefore, the development of antimicrobial packaging, using extracts, could improve food quality and safety, thus the use of these extracts has great potential in the food industry. For this reason, and in relation to new lines of research, the manufacture of antibacterial food packaging, where plant extracts are isolated or combined with photodynamic inactivation (PDI), can be profitable and sustainable, as discussed in Olszewska, G˛edas, and Simões (2020) [75]. 3.4. Structure–Bioactivity Relationship Antioxidant activity of phenolic compounds has been related to its structure. Its observed biological activity has been associated with the compounds phenolic –OH group, hydrophobic properties associated with the benzene ring, the methyl and isopropyl groups, the binding affinity for the guanine residue of DNA, and the anti-inflammatory, apoptotic, and disruptive activities on the cell membrane [ 76 ]. Additionally, the presence of a second hydroxyl or an amino group in oor p-position are related to a better antiradical and antioxidant performance [ 77 ]. The number and position of these hydroxyl groups and their influence on bioactivity has been established in the literature, as related to their strong donating effect and formation of a stable quinone [ 78 , 79 ]. In this scenario, antioxidant activity could depend on interactions between phenolic compounds and bacterial cells’ surfaces, unrelated to a specific phenolic group. In the studied extracts, the ortho position (catechol groups) among the aromatic phenolic ring seems to be the predominant configuration for most of the phenolic acids and other phenolic compounds identified. The presence of these multiple –OH groups is prominent in compounds, such as rosmarinic acid or luteolin, rutin, naringenin, catechin, and their derivatives. Rosmarinic acid presents in its structure two ortho-dihydroxy groups (catechol structure), which could be related to its high antioxidant activity. This compound has been found in most studied spices, showing high concentrations especially in those belonging to the Lamiaceae family. Oregano and rosemary also present high levels of caffeic acid and other caffeoyl derivatives. Having a highly similar structure to rosmarinic acid, their presence is related to a higher scavenging activity in the two Lamiaceae spices. Caffeic acid has also been found in ginger extracts [80]. Phenolic diterpenes, such as carnosol and carnosic acid, also present a catechol structure in their aromatic ring. Consequently, their presence in certain extracts can potentially impact their attributed antioxidant activity. From other spices belonging to the Lamiaceae family, rosemary shows the highest concentrations of these phenolic compounds. Flavonoids are also found in the mentioned extracts. In this case, their antioxidant activity results from the location and presence of hydroxyl and oxo groups and double bonds [ 81 , 82 ]. Specially, some combinations have been related to higher biological activity. The presence of a 4-oxo group with either an unsaturated bond between C2 and C3 or OH groups near C3 and C5 has correlated with better bioactivity [83]. This has been observed in some molecules found in these extracts, such as apigenin, quercetin, luteolin, and rutin. Additionally, compounds, like luteolin, also present a catechol group in the B-ring, which could enhance their bioactivity [83]. The mentioned flavonoids have been identified in rosemary, thyme, oregano, and clove. However, the variation in the concentration of flavonoids and other compounds (like protocatechuic and chlorogenic acid) in different studies (which could be related to the extraction conditions and other factors previously discussed) could lead to a reduced contribution to the studied activity. Even though the considered Lamiaceae extracts appear to have a similar profile, rosemary seems to exhibit higher antioxidant activity throughout different studies. This difference could be related to the higher concentration of important antioxidant molecules Foods 2023,12, 3031 18 of 23 in its extracts, as mentioned for rosmarinic acid, or the synergistic effect of its specific polyphenolic combination as compared to oregano or thyme. As for the antioxidant activity in clove extracts, this has been related to their composition of gallic acid, flavonols, and hydrolysable tannins. The high concentration of gallic acid specifically and its derivatives, which present three hydroxy groups in their structure, could be related to their high antioxidant activity, reported as the highest in comparison to other 26 spices [36]. 3.5. Comparison of Spice Extracts with Other Common Additives As these extracts seem to have an outstanding antioxidant potential, it is interesting to consider its comparative study with additives already in use, both natural and synthetic, for its evaluation for use in the food industry. Also, analyzing spices in food matrices offers important information about potential factors that could interfere in the final products. Methanolic thyme extracts have already shown greater antioxidant activity than known additives BHA, TBHQ, and α -tocopherol [ 34 ]. As for extraction solvents, the best polyphenolic extraction from thyme has been achieved using lower concentrations of ethanol with MAE [ 38 ]. In Bouymajane et al. (2022), antioxidant capacity of extracts from aereal parts of Thymus zygis subsp. gracillis was evaluated using DPPH, establishing an IC50 of 0.234 ±0.001 mg/mL, higher than the reference standard BHT [67]. In Jayathilakan, Sharma, Radhakrishna, and Bawa (2007), the antioxidant activity of clove (Eugenia caryophyllata) was evaluated in meat, both cooked and chilled, and compared with the antioxidants TBHQ and BHA [ 62 ]. Results showed that antioxidant activity presented the following order: clove (finely pulverized) > ascorbic acid > cinnamon (finely pulverized) and TBHQ > BHA. In the present study, as in the majority where the antioxidant and antimicrobial capacity of spices in food are compared, sensory characteristics, such as meat color and flavor, are also evaluated, with the aim of analyzing the acceptance of the final product with natural additives by consumers. Fresh aromatic plants are more popular, but dry extracts contribute more to the biological value [30]. Additionally, the antimicrobial capacity of clove extracts has been evaluated in comparison with the additive TBHQ and ethanol [ 46 ]. MIC values ( µ g/mL) for Gram-positive and -negative bacteria, respectively, were 50 and 100 for an ethanolic clove extract, 25 and 50 for TBHQ, and 50 and 100 for ethanol. A relation between a higher amount of total phenolic compounds and a relatively high antibacterial activity was observed. It was also concluded that the extraction of bioactive chemicals with high polarity solvents was more effective than extraction with low polarity solvents. Regarding clove, eugenol is its main bioactive compound, found in concentrations ranging between 9381 mg and 14,650 mg per 100 g of fresh plant material [ 84 ]. Compared with BHT, cloves (sprouts) were the spice with the highest antioxidant activity (168.660 mmol of Trolox/100 g dry weight) and polyphenol content (14.380 gallic acid equivalents/100 g dry weight) [ 36 ]. Similar results have been observed on cooked beef patties, where clove extracts presented an increased antioxidant potential on protein and lipid oxidation when compared with BHT and ascorbic acid [63]. The antioxidant capacity of rosemary extract included in pork patties was evaluated using vitamin E as a control [ 60 ]. This was further confirmed by Sebranek et al. (2005), where the antioxidant effect of rosemary extracts on frozen raw sausages also proved to be higher than BHA and BHT [ 61 ]. Results showed that the extracts retarded lipid oxidation during meat processing. Also, in Zahid et al. (2020), ascorbic acid was used to evaluate the antioxidant capacity of cloves in cooked beef patties using the TBARS method [ 63 ]. It was also concluded that the addition of clove as a natural antioxidant could reduce the oxidation of proteins and lipids and improve the organoleptic quality of the food product. Natural compounds used as additives in food could be a viable alternative to address the problem of microbial resistance, constitute new sources of antioxidant compounds, and hamper the negative effects of some synthetic compounds. Also, plant extracts have the added value of meeting the requirements of food safety because spices are GRAS Foods 2023,12, 3031 19 of 23 substances and do not have a negative impact on nutritional and sensory attributes of foodstuffs, providing that the appropriate content should be taken into account for this purpose [ 82 ]. However, there is still a lack of knowledge regarding their inclusion on different food matrices and the evaluation of both their antimicrobial and antioxidant activities on these formulations. In this sense, studies should also take into consideration the implications of the introduction of phenolic extract on food color, flavor, odor, bitterness, and astringency, and its impact on consumer acceptance should be evaluated. Additionally, it is necessary to address the stability of these bioactive compounds in formulations during food storage time that could present a limitation on their applicability. 4. Conclusions In the present systematic review, the literature regarding medicinal and aromatic plants’ extracts has been evaluated. An abundance of extraction techniques has been applied through the literature for the obtention of related extracts. In this sense, the development of protocols for environmentally friendly techniques is an area of study of interest for the future of the food industry. These extracts present an interesting bioactive compound content. While this has been evaluated for some extracts, a lack of individual and detailed characterization of polyphenols has been found in some studies, which may have hindered the study of the potential correlation of a specific phenolic composition with their observed antioxidant capacity. Nevertheless, a high bioactivity associated with their phenolic content has been observed for the considered spices. While there is a clear association between phenolic compounds and antioxidant capacity, this same technological function is not attributed to a single isolated phenolic compound, but to several together, which act in synergy. On the other hand, relationships between phenolic content in food and antimicrobial capacity is not yet clear, although a higher amount of those compounds may be related to higher activity. The effect of spices on food pathogens depends on the phenolic content, but also on the interaction with other food components. Spices’ extracts thus present great potential for their use in the food industry. When transferring the use of plant extracts as antioxidant and antimicrobial material in the food industry, we have to take into account two important aspects: (1) It has to be considered that phenolic compounds included in food could contribute to the color, flavor, odor, bitterness, and astringency, so it is important to study and control the dose of plant extracts added to food; and (2) careful considerations should be given to the stability of bioactive compounds during food storage time. In this regard, spices could be an attractive alternative not only for improving food preservation, but also to help decrease their sensory effect in certain foods. Author Contributions: Conceptualization, J.L.-S. and I.B.-L.; methodology, C.D.-S. and A.R.-V.; investigation, C.D.-S., A.R.-V., A.R.-R., R.Q.-P., I.B.-L. and J.L.-S.; writing—original draft preparation, C.D.-S., A.R.-R. and A.R.-R.; writing—review and editing, R.Q.-P., I.B.-L. and J.L.-S.; supervision, J.L.-S. and I.B.-L. All authors have read and agreed to the published version of the manuscript. Funding: This research received no external funding. Data Availability Statement: No new data were created or analyzed in this study. Data sharing is not applicable to this article. Acknowledgments: C.D.-S. is grateful for the Doctoral Program in Nutrition and Food Sciences, University of Granada (grant from the Regional Government of Andalucía PREDOC_00110). Conflicts of Interest: The authors declare no conflict of interest. Foods 2023,12, 3031 20 of 23 References 1. Gómez-García, R.; Campos, D.A.; Aguilar, C.N.; Madureira, A.R.; Pintado, M. Valorisation of food agro-industrial by-products: From the past to the present and perspectives. J. Environ. Manag. 2021,299, 113571. [CrossRef] 2. Beya, M.M.; Netzel, M.E.; Sultanbawa, Y.; Smyth, H.; Hoffman, L.C. Plant-Based Phenolic Molecules as Natural Preservatives in Comminuted Meats: A Review. Antioxidants 2021,10, 263. [CrossRef] [PubMed] 3. Pop, A.; Muste, S.; Paucean, A.; Chis, S.; Man, S.; Salanta, L.; Marc, R.; Muresan, A.; Martis, G. Herbs and spices in terms of food preservation and shelf life. Hop Med. Plants 2019,27, 57–65. 4. Dougkas, A.; Vannereux, M.; Giboreau, A. The Impact of Herbs and Spices on Increasing the Appreciation and Intake of Low-Salt Legume-Based Meals. Nutrients 2019,11, 2901. [CrossRef] [PubMed] 5. Vázquez-Fresno, R.; Rosana, A.R.R.; Sajed, T.; Onookome-Okome, T.; Wishart, N.A.; Wishart, D.S. Herbs and SpicesBiomarkers of Intake Based on Human Intervention Studies—A Systematic Review. Genes Nutr. 2019,14, 18. [CrossRef] 6. Zhang, J.; Zhang, M.; Ju, R.; Chen, K.; Bhandari, B.; Wang, H. Advances in efficient extraction of essential oils from spices and its application in food industry: A critical review. Crit. Rev. Food Sci. Nutr. 2022, 1–22. [CrossRef] 7. Omoarukhe, E.D.; Harbourne, N.; Jauregi, P. The Effect of Cinnamon and Ginger Spices on Anthocyanins in Sweetened Roselle Beverages. Beverages 2023,9, 24. [CrossRef] 8. Peters, J.C.; Marker, R.; Pan, Z.; Breen, J.A.; Hill, J.O. The Influence of Adding Spices to Reduced Sugar Foods on Overall Liking. J. Food Sci. 2018,83, 814–821. [CrossRef] 9. Fierascu, R.C.; Fierascu, I.; Baroi, A.M.; Ortan, A. Selected Aspects Related to Medicinal and Aromatic Plants as Alternative Sources of Bioactive Compounds. Int. J. Mol. Sci. 2021,22, 1521. [CrossRef] 10. Robards, K.; Prenzler, P.D.; Tucker, G.; Swatsitang, P.; Glover, W. Phenolic compounds and their role in oxidative processes in fruits. Food Chem. 1999,66, 401–436. [CrossRef] 11. Fierascu, R.C.; Fierascu, I.; Ortan, A.; Georgiev, M.I.; Sieniawska, E. Innovative Approaches for Recovery of Phytoconstituents from Medicinal/Aromatic Plants and Biotechnological Production. Molecules 2020,25, 309. [CrossRef] 12. Domínguez, R.; Pateiro, M.; Munekata, P.E.S.; McClements, D.J.; Lorenzo, J.M. Encapsulation of Bioactive Phytochemicals in Plant-Based Matrices and Application as Additives in Meat and Meat Products. Molecules 2021,26, 3984. [CrossRef] [PubMed] 13. Falleh, H.; Ben Jemaa, M.; Saada, M.; Ksouri, R. Essential oils: A promising eco-friendly food preservative. Food Chem. 2020 , 330, 127268. [CrossRef] 14. Chrysargyris, A.; Mikallou, M.; Petropoulos, S.; Tzortzakis, N. Profiling of Essential Oils Components and Polyphenols for Their Antioxidant Activity of Medicinal and Aromatic Plants Grown in Different Environmental Conditions. Agronomy 2020 ,10, 727. [CrossRef] 15. Martins, N.; Barros, L.; Ferreira, I.C.F.R. In vivo antioxidant activity of phenolic compounds: Facts and gaps. Trends Food Sci. Technol. 2016,48, 1–12. [CrossRef] 16. Takó, M.; Kerekes, E.B.; Zambrano, C.; Kotogán, A.; Papp, T.; Krisch, J.; Vágvölgyi, C. Plant Phenolics and Phenolic-Enriched Extracts as Antimicrobial Agents against Food-Contaminating Microorganisms. Antioxidants 2020,9, 165. [CrossRef] [PubMed] 17. Zeb, A. Concept, mechanism, and applications of phenolic antioxidants in foods. J. Food Biochem. 2020,44, e13394. [CrossRef] 18. Guardiola, S.; Mach, N. Potencial terapéutico del Hibiscus sabdariffa: Una revisión de las evidencias científicas. Endocrinología y Nutrició2014,61, 274–295. [CrossRef] [PubMed] 19. Malhotra, B.; Keshwani, A.; Kharkwal, H. Antimicrobial food packaging: Potential and pitfalls. Front. Microbiol. 2015 ,6, 611. [CrossRef] [PubMed] 20. Regulation, European_Commission. No 1333/2008 of the European Parliament and of the Council of 16 December 2008 on Food Aditives. Off. J. Eur. Union 2008,354, 16–33. 21. Teng, X.; Zhang, M.; Devahastin, S. New developments on ultrasound-assisted processing and flavor detection of spices: A review. Ultrason. Sonochem. 2019,55, 297–307. [CrossRef] 22. Žlabur, J.Š.; Brajer, M.; Vo´ca, S.; Gali´c, A.; Radman, S.; Rimac-Brnˇci´c, S.; Xia, Q.; Zhu, Z.; Grimi, N.; Barba, F.J.; et al. Ultrasound as a Promising Tool for the Green Extraction of Specialized Metabolites from Some Culinary Spices. Molecules 2021 ,26, 1866. [CrossRef] 23. Bellumori, M.; Innocenti, M.; Binello, A.; Boffa, L.; Mulinacci, N.; Cravotto, G. Selective recovery of rosmarinic and carnosic acids from rosemary leaves under ultrasoundand microwave-assisted extraction procedures. C. R. Chim. 2016 ,19, 699–706. [CrossRef] 24. Proestos, C.; Komaitis, M. Ultrasonically assisted extraction of phenolic compounds from aromatic plants: Comparison with conventional extraction technics. J. Food Qual. 2006,29, 567–582. [CrossRef] 25. Wang, H.; Provan, G.J.; Helliwell, K. Determination of rosmarinic acid and caffeic acid in aromatic herbs by HPLC. Food Chem. 2004,87, 307–311. [CrossRef] 26. Švarc-Gaji´c, J.; Stojanovi´c, Z.; Segura Carretero, A.; Arráez Román, D.; Borrás, I.; Vasiljevi´c, I. Development of a microwaveassisted extraction for the analysis of phenolic compounds from Rosmarinus officinalis.J. Food Eng. 2013 ,119, 525–532. [CrossRef] 27. Gouda, M.; El-Din Bekhit, A.; Tang, Y.; Huang, Y.; Huang, L.; He, Y.; Li, X. Recent innovations of ultrasound green technology in herbal phytochemistry: A review. Ultrason. Sonochem. 2021,73, 105538. [CrossRef] [PubMed] 28. Tzima, K.; Brunton, N.P.; Lyng, J.G.; Frontuto, D.; Rai, D.K. The effect of Pulsed Electric Field as a pre-treatment step in Ultrasound Assisted Extraction of phenolic compounds from fresh rosemary and thyme by-products. Innov. Food Sci. Emerg. Technol. 2021 , 69, 102644. [CrossRef] Foods 2023,12, 3031 21 of 23 29. Barbieri, J.B.; Goltz, C.; Batistão Cavalheiro, F.; Theodoro Toci, A.; Igarashi-Mafra, L.; Mafra, M.R. Deep eutectic solvents applied in the extraction and stabilization of rosemary (Rosmarinus officinalis L.) phenolic compounds. Ind. Crops Prod. 2020 ,144, 112049. [CrossRef] 30. Josipovi´c, R.; Kneževi´c, Z.M.; Frece, J.; Markov, K.; Kazazi´c, S.; Mrvˇci´c, J. Improved Properties and Microbiological Safety of Novel Cottage Cheese Containing Spices. Food Technol. Biotechnol. 2015,53, 454–462. [CrossRef] 31. Gonelimali, F.D.; Lin, J.; Miao, W.; Xuan, J.; Charles, F.; Chen, M.; Hatab, S.R. Antimicrobial properties and mechanism of action of some plant extracts against food pathogens and spoilage microorganisms. Front. Microbiol. 2018 ,9, 389103. [CrossRef] [PubMed] 32. Carvalho, R.N.; Moura, L.S.; Rosa, P.T.V.; Meireles, M.A.A. Supercritical fluid extraction from rosemary (Rosmarinus officinalis): Kinetic data, extract’s global yield, composition, and antioxidant activity. J. Supercrit. Fluids 2005,35, 197–204. [CrossRef] 33. Mena, P.; Cirlini, M.; Tassotti, M.; Herrlinger, K.A.; Dall’Asta, C.; Del Rio, D. Phytochemical Profiling of Flavonoids, Phenolic Acids, Terpenoids, and Volatile Fraction of a Rosemary (Rosmarinus officinalis L.) Extract. Molecules 2016,21, 1576. [CrossRef] 34. Roby, M.H.H.; Sarhan, M.A.; Selim, K.A.H.; Khalel, K.I. Evaluation of antioxidant activity, total phenols and phenolic compounds in thyme (Thymus vulgaris L.), sage (Salvia officinalis L.), and marjoram (Origanum majorana L.) extracts. Ind. Crops Prod. 2013 ,43, 827–831. [CrossRef] 35. Mostafa, A.A.; Al-Askar, A.A.; Almaary, K.S.; Dawoud, T.M.; Sholkamy, E.N.; Bakri, M.M. Antimicrobial activity of some plant extracts against bacterial strains causing food poisoning diseases. Saudi J. Biol. Sci. 2018,25, 361–366. [CrossRef] 36. Shan, B.; Cai, Y.Z.; Sun, M.; Corke, H. Antioxidant capacity of 26 spice extracts and characterization of their phenolic constituents. J. Agric. Food Chem. 2005,53, 7749–7759. [CrossRef] 37. Munekata, P.E.S.; Alcántara, C.; Žugˇci´c, T.; Abdelkebir, R.; Collado, M.C.; García-Pérez, J.V.; Jambrak, A.R.; Gavahian, M.; Barba, F.J.; Lorenzo, J.M. Impact of ultrasound-assisted extraction and solvent composition on bioactive compounds and in vitro biological activities of thyme and rosemary. Food Res. Int. 2020,134, 109242. [CrossRef] 38. Nabet, N.; Gilbert-López, B.; Madani, K.; Herrero, M.; Ibáñez, E.; Mendiola, J.A. Optimization of microwave-assisted extraction recovery of bioactive compounds from Origanum glandulosum and Thymus fontanesii. Ind. Crops Prod. 2019 ,129, 395–404. [CrossRef] 39. Proestos, C.; Lytoudi, K.; Mavromelanidou, O.K.; Zoumpoulakis, P.; Sinanoglou, V.J. Antioxidant Capacity of Selected Plant Extracts and Their Essential Oils. Antioxidants 2013,2, 11–22. [CrossRef] 40. Rosarior, V.L.; Lim, P.S.; Wong, W.K.; Yue, C.S.; Yam, H.C.; Tan, S.A. Antioxidant-rich Clove Extract, A Strong Antimicrobial Agent against Urinary Tract Infections-causing Bacteria in vitro.Trop. Life Sci. Res. 2021,32, 45. [CrossRef] 41. Rocío Teruel, M.; Garrido, M.D.; Espinosa, M.C.; Linares, M.B. Effect of different format-solvent rosemary extracts (Rosmarinus officinalis) on frozen chicken nuggets quality. Food Chem. 2015,172, 40–46. [CrossRef] 42. Thorsen, M.A.; Hildebrandt, K.S. Quantitative determination of phenolic diterpenes in rosemary extracts: Aspects of accurate quantification. J. Chromatogr. A 2003,995, 119–125. [CrossRef] 43. Vallverdú-Queralt, A.; Regueiro, J.; Martínez-Huélamo, M.; Rinaldi Alvarenga, J.F.; Leal, L.N.; Lamuela-Raventos, R.M. A comprehensive study on the phenolic profile of widely used culinary herbs and spices: Rosemary, thyme, oregano, cinnamon, cumin and bay. Food Chem. 2014,154, 299–307. [CrossRef] 44. Barbero, G.F.; Liazid, A.; Palma, M.; Barroso, C.G. Ultrasound-assisted extraction of capsaicinoids from peppers. Talanta 2008 ,75, 1332–1337. [CrossRef] 45. Borrás Linares, I.; Arráez-Román, D.; Herrero, M.; Ibáñez, E.; Segura-Carretero, A.; Fernández-Gutiérrez, A. Comparison of different extraction procedures for the comprehensive characterization of bioactive phenolic compounds in Rosmarinus officinalis by reversed-phase high-performance liquid chromatography with diode array detection coupled to electrospray time-of-flight mass spectrometry. J. Chromatogr. A 2011,1218, 7682–7690. [CrossRef] 46. El-Maati, M.F.A.; Mahgoub, S.A.; Labib, S.M.; Al-Gaby, A.M.A.; Ramadan, M.F. Phenolic extracts of clove (Syzygium aromaticum) with novel antioxidant and antibacterial activities. Eur. J. Integr. Med. 2016,8, 494–504. [CrossRef] 47. Kim, I.S.; Yang, M.R.; Lee, O.H.; Kang, S.N. Antioxidant Activities of Hot Water Extracts from Various Spices. Int. J. Mol. Sci. 2011,12, 4120–4131. [CrossRef] [PubMed] 48. Kivilompolo, M.; Hyötyläinen, T. Comprehensive two-dimensional liquid chromatography in analysis of Lamiaceae herbs: Characterisation and quantification of antioxidant phenolic acids. J. Chromatogr. A 2007,1145, 155–164. [CrossRef] 49. Nikolin, B.; Imamovi´c, B.; Medanhodzi´c-Vuk, S.; Sober, M. High perfomance liquid chromatography in pharmaceutical analyses. Bosn. J. Basic Med. Sci. 2004,4, 5. [CrossRef] 50. Li, H.; Wu, X.; Li, X.; Cao, X.; Li, Y.; Cao, H.; Men, Y. Multistage Extraction of Star Anise and Black Pepper Derivatives for Antibacterial, Antioxidant, and Anticancer Activity. Front. Chem. 2021,9, 660138. [CrossRef] [PubMed] 51. Gediko˘glu, A.; Sökmen, M.; Çivit, A. Evaluation of Thymus vulgaris and Thymbra spicata essential oils and plant extracts for chemical composition, antioxidant, and antimicrobial properties. Food Sci. Nutr. 2019,7, 1704–1714. [CrossRef] 52. Miron, T.L.; Plaza, M.; Bahrim, G.; Ibáñez, E.; Herrero, M. Chemical composition of bioactive pressurized extracts of Romanian aromatic plants. J. Chromatogr. A 2011,1218, 4918–4927. [CrossRef] 53. Yoo, K.M.; Kim, D.O.; Lee, C.Y. Evaluation of different methods of antioxidant measurement. Food Sci. Biotechnol. 2007 ,16, 177–182. 54. Moon, J.-K.; Shibamoto, T. Antioxidant Assays for Plant and Food Components. J. Agric. Food Chem. 2009 ,57, 1655–1666. [CrossRef] [PubMed] Foods 2023,12, 3031 22 of 23 55. Zhong, Y.; Shahidi, F. Methods for the assessment of antioxidant activity in foods. In Handbook of Antioxidants for Food Preservation; Elsevier: Amsterdam, The Netherlands, 2015; pp. 287–333. 56. Çelik, G.; Kılıç, G.; Kanbolat, ¸S.; Özlem ¸Sener, S.; Karaköse, M.; Yaylı, N.; Karao˘glu, ¸S.A. Biological activity, and volatile and phenolic compounds from five Lamiaceae species. Flavour Fragr. J. 2021,36, 223–232. [CrossRef] 57. Hcini, K.; Bahi, A.; Zarroug, M.B.; Ben Farhat, M.; Lozano-Pérez, A.A.; Cenis, J.L.; Quílez, M.; Stambouli-Essassi, S.; Jordán, M.J. Polyphenolic Profile of Tunisian Thyme (Thymbra capitata L.) Post-Distilled Residues: Evaluation of Total Phenolic Content and Phenolic Compounds and Their Contribution to Antioxidant Activity. Molecules 2022,27, 8791. [CrossRef] [PubMed] 58. Georgieva, P.I.; Vasileva, I.N.; Parzhanova, A.B.; Chalova, V.I.; Ivanova, S.D.; Slavov, A.M. Factors affecting the amount of biologically active substances in extracts of Bulgarian medical plants typical of Western Rhodopes. Bulg. Chem. Commun. 2022 ,54, 74–80. 59. Horba´nczuk, O.K.; Kurek, M.A.; Atanasov, A.G.; Brnˇci´c, M.; Brnˇci´c, S.R. The Effect of Natural Antioxidants on Quality and Shelf Life of Beef and Beef Products. Food Technol. Biotechnol. 2019,57, 439. [CrossRef] [PubMed] 60. Nissen, L.R.; Byrne, D.V.; Bertelsen, G.; Skibsted, L.H. The antioxidative activity of plant extracts in cooked pork patties as evaluated by descriptive sensory profiling and chemical analysis. Meat Sci. 2004,68, 485–495. [CrossRef] 61. Sebranek, J.G.; Sewalt, V.J.H.; Robbins, K.L.; Houser, T.A. Comparison of a natural rosemary extract and BHA/BHT for relative antioxidant effectiveness in pork sausage. Meat Sci. 2005,69, 289–296. [CrossRef] 62. Jayathilakan, K.; Sharma, G.K.; Radhakrishna, K.; Bawa, A.S. Antioxidant potential of synthetic and natural antioxidants and its effect on warmed-over-flavour in different species of meat. Food Chem. 2007,105, 908–916. [CrossRef] 63. Zahid, M.A.; Choi, J.Y.; Seo, J.K.; Parvin, R.; Ko, J.; Yang, H.S. Effects of clove extract on oxidative stability and sensory attributes in cooked beef patties at refrigerated storage. Meat Sci. 2020,161, 107972. [CrossRef] [PubMed] 64. Costa, D.C.; Costa, H.S.; Albuquerque, T.G.; Ramos, F.; Castilho, M.C.; Sanches-Silva, A. Advances in phenolic compounds analysis of aromatic plants and their potential applications. Trends Food Sci. Technol. 2015,45, 336–354. [CrossRef] 65. Jeon, S.G.; Kayama, H.; Ueda, Y.; Takahashi, T.; Asahara, T.; Tsuji, H.; Tsuji, N.M.; Kiyono, H.; Ma, J.S.; Kusu, T.; et al. Probiotic Bifidobacterium breve Induces IL-10-Producing Tr1 Cells in the Colon. PLoS Pathog. 2012,8, e1002714. [CrossRef] [PubMed] 66. Karre, L.; Lopez, K.; Getty, K.J.K. Natural antioxidants in meat and poultry products. Meat Sci. 2013,94, 220–227. [CrossRef] 67. Bouymajane, A.; Filali, F.R.; El Majdoub, Y.O.; Ouadik, M.; Abdelilah, R.; Cavò, E.; Miceli, N.; Taviano, M.F.; Mondello, L.; Cacciola, F. Phenolic Compounds, Antioxidant and Antibacterial Activities of Extracts from Aerial Parts of Thymus zygis subsp. gracilis, Mentha suaveolens and Sideritis incana from Morocco. Chem. Biodivers. 2022,19, e202101018. [CrossRef] 68. Mascoloti Spréa, R.; Caleja, C.; Pinela, J.; Finimundy, T.C.; Calhelha, R.C.; Kosti´c, M.; Sokovic, M.; Prieto, M.A.; Pereira, E.; Amaral, J.S.; et al. Comparative study on the phenolic composition and in vitro bioactivity of medicinal and aromatic plants from the Lamiaceae family. Food Res. Int. 2022,161, 111875. [CrossRef] 69. Mao, Q.Q.; Xu, X.Y.; Cao, S.Y.; Gan, R.Y.; Corke, H.; Beta, T.; Li, H. Bin Bioactive Compounds and Bioactivities of Ginger (Zingiber officinale Roscoe). Foods 2019,8, 185. [CrossRef] 70. Pinto, T.; Aires, A.; Cosme, F.; Bacelar, E.; Morais, M.C.; Oliveira, I.; Ferreira-Cardoso, J.; Anjos, R.; Vilela, A.; Gonçalves, B. Bioactive (Poly)phenols, Volatile Compounds from Vegetables, Medicinal and Aromatic Plants. Foods 2021,10, 106. [CrossRef] 71. Chang, J.S.; Wang, K.C.; Yeh, C.F.; Shieh, D.E.; Chiang, L.C. Fresh ginger (Zingiber officinale) has anti-viral activity against human respiratory syncytial virus in human respiratory tract cell lines. J. Ethnopharmacol. 2013,145, 146–151. [CrossRef] 72. Žitek, T.; Borjan, D.; Golle, A.; Knez, Ž.; Knez, M. Optimization of Extraction of Phenolic Compounds with Antimicrobial Properties from Origanum vulgare. Processes 2021,9, 1032. [CrossRef] 73. Zhong, X.; Wang, X.; Zhou, N.; Li, J.; Liu, J.; Yue, J.; Hao, X.; Gan, M.; Lin, P.; Shang, X. Chemical characterization of the polar antibacterial fraction of the ethanol extract from Rosmarinus officinalis.Food Chem. 2021,344, 128674. [CrossRef] 74. Pisoschi, A.M.; Pop, A.; Georgescu, C.; Turcu¸s, V.; Olah, N.K.; Mathe, E. An overview of natural antimicrobials role in food. Eur. J. Med. Chem. 2018,143, 922–935. [CrossRef] 75. Olszewska, M.A.; G˛edas, A.; Simões, M. Antimicrobial polyphenol-rich extracts: Applications and limitations in the food industry. Food Res. Int. 2020,134, 109214. [CrossRef] [PubMed] 76. Friedman, M. Chemistry and multibeneficial bioactivities of carvacrol (4-isopropyl-2-methylphenol), a component of essential oils produced by aromatic plants and spices. J. Agric. Food Chem. 2014,62, 7652–7670. [CrossRef] 77. Ali, H.M.; Abo-Shady, A.; Sharaf Eldeen, H.A.; Soror, H.A.; Shousha, W.G.; Abdel-Barry, O.A.; Saleh, A.M. Structural features, kinetics and SAR study of radical scavenging and antioxidant activities of phenolic and anilinic compounds. Chem. Cent. J. 2013 , 7, 53. [CrossRef] [PubMed] 78. Siquet, C.; Paiva-Martins, F.; Lima, J.L.F.C.; Reis, S.; Borges, F. Antioxidant profile of dihydroxyand trihydroxyphenolic acids-A structure–activity relationship study. Free Radic. Res. 2009,40, 433–442. [CrossRef] 79. Muhammad, A.; Tel-Çayan, G.; Öztürk, M.; Duru, M.E.; Nadeem, S.; Anis, I.; Ng, S.W.; Shah, M.R. Phytochemicals from Dodonaea viscosa and their antioxidant and anticholinesterase activities with structure–activity relationships. Pharm. Biol. 2016 , 54, 1649–1655. [CrossRef] 80. Tohma, H.; Köksal, E.; Kılıç, Ö.; Alan, Y.; Abdullah Yılmaz, M.; Gülçin, ˙ I.; Bursal, E.; Alwasel, S.H. RP-HPLC/MS/MS Analysis of the Phenolic Compounds, Antioxidant and Antimicrobial Activities of Salvia L. Species. Antioxidants 2016 ,5, 38. [CrossRef] [PubMed] Foods 2023,12, 3031 23 of 23 81. Masuoka, N.; Matsuda, M.; Kubo, I. Characterisation of the antioxidant activity of flavonoids. Food Chem. 2012 ,131, 541–545. [CrossRef] 82. Kurek-Górecka, A.; Rzepecka-Stojko, A.; Górecki, M.; Stojko, J.; Sosada, M.; ´ Swierczek-Zi˛eba, G. Structure and Antioxidant Activity of Polyphenols Derived from Propolis. Molecules 2013,19, 78–101. [CrossRef] [PubMed] 83. Wojtunik-Kulesza, K.; Oniszczuk, A.; Oniszczuk, T.; Combrzy´nski, M.; Nowakowska, D.; Matwijczuk, A. Influence of In Vitro Digestion on Composition, Bioaccessibility and Antioxidant Activity of Food Polyphenols-A Non-Systematic Review. Nutrients 2020,12, 1401. [CrossRef] [PubMed] 84. Showing All Polyphenols Found in Cloves—Phenol-Explorer. Available online: http://phenol-explorer.eu/contents/food/797 (accessed on 4 August 2023). Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.