STUDY OF THE LIPID AND CAROTENOID COMPOSITION OF CARROT RESIDUES

RESEARCH AND DEVELOPMENT TADQIQOT VA TARAQQIYOT ISSN: 3030 – 3281 Volume II, Issue 12 (2025) © 2025, the Author(s). Published by IMFAKTOR. This is an open access article under the CC BY license http://creativecommons.org/licenses/by/4.0/ 40 Carrot (Daucus carota L.) is a widely consumed and nutritionally valuable vegetable, recognized for its high content of carotenoids—particularly β-carotene—as well as various lipid fractions that contribute to its functional and health-promoting properties. These bioactive compounds are associated with antioxidant activity and play an important role in human nutrition and disease prevention. STUDY OF THE LIPID AND CAROTENOID COMPOSITION OF CARROT RESIDUES Mumtoza YUSUPOVA¹, Farida ISLAMOVA2, Dilrabo MAKSUMOVA3. ¹ Master’s student at the Tashkent Institute of Chemical Technology. 2 Senior Lecturer at the Tashkent Institute of Chemical Technology. 3 Candidate of Technical Sciences (PhD), Associate Professor at the Tashkent Institute of Chemical Technology. https://doi.org/10.5281/zenodo.17995219 ANNOTATION In this study, a comprehensive chemical analysis of the lipid and carotenoid composition of locally grown carrot varieties and their juice extraction residues was conducted for the first time. Quantitative differences in lipids and carotenoids between fresh and dried residues were evaluated, and the major classes of compounds within neutral lipids were identified. The results demonstrate the potential of carrot processing residues as a valuable source of biologically active compounds. Furthermore, the findings provide a scientific basis for the valorization of agro-industrial by-products in the development of functional foods and nutraceuticals. This work contributes to a deeper understanding of compositional changes during processing and supports the sustainable utilization of plant-based resources. Keywords: carrot, secondary raw materials, active ingredients, lipids, Soxhlet apparatus, chemical analysis, carotenoids. SABZI QOLDIQLARINING LIPID VA KAROTENOID TARKIBINI O'RGANISH ANNOTATSIYA Ushbu tadqiqotda mahalliy sharoitda yetishtirilgan sabzi navlari hamda ularning sharbat olish jarayonida hosil bo‘ladigan qoldiqlaridagi lipid va karotinoid tarkibi ilk bor kompleks kimyoviy tahlil qilindi. Yangi va quritilgan qoldiqlardagi lipidlar va karotinoidlar miqdoridagi farqlar baholandi, shuningdek neytral lipidlar tarkibidagi birikmalarning asosiy sinflari aniqlandi. Olingan natijalar sabzi qayta ishlash qoldiqlarining biologik faol moddalarning qimmatli manbai sifatidagi salohiyatini ko‘rsatadi. Bundan tashqari, ushbu topilmalar funksional oziq-ovqat mahsulotlari va nutrasevtiklarni ishlab chiqishda agro-sanoat chiqindilarini valorizatsiya qilish uchun ilmiy asos bo‘lib xizmat qiladi. Mazkur ish qayta ishlash jarayonida tarkibiy o‘zgarishlarni chuqurroq anglashga hissa qo‘shadi va o‘simlik manbalaridan barqaror foydalanishni qo‘llab-quvvatlaydi. Kalit so‘zlar: sabzi, ikkilamchi xomashyo, faol moddalar, lipid, Sokslet apparati, kimyoviy tahlil, karatinoid. ИЗУЧЕНИЕ ЛИПИДНОГО И КАРОТИНОИДНОГО СОСТАВА ОСТАТКОВ МОРКОВИ АННОТАЦИЯ В настоящем исследовании впервые был проведён комплексный химический анализ липидного и каротиноидного состава местных сортов моркови и остатков, образующихся после экстракции сока. Оценены количественные различия в содержании липидов и каротиноидов между свежими и высушенными остатками, а также идентифицированы основные классы соединений в составе нейтральных липидов. Полученные результаты демонстрируют потенциал отходов переработки моркови как ценного источника биологически активных соединений. Кроме того, данные выводы формируют научную основу для валоризации агропромышленных побочных продуктов при разработке функциональных пищевых продуктов и нутрицевтиков. Настоящая работа способствует более глубокому пониманию изменений состава в процессе переработки и поддерживает устойчивое использование растительных ресурсов. Ключевые слова: морковь, вторичное сырье, активные ингредиенты, липиды, аппарат Сокслета, химический анализ, каротиноиды . TADQIQOT VA TARAQQIYOT | II-JILD | 12-SON | 2025 \ 41 In recent years, increasing attention has been paid to the comprehensive utilization of plant raw materials in order to enhance resource efficiency and reduce environmental impact. During industrial-scale carrot juice production, substantial quantities of solid residues, commonly referred to as pomace, are generated as byproducts. This pomace is typically considered waste or used for low-value applications such as animal feed, despite its rich chemical composition. However, previous studies suggest that such residues may still contain significant levels of valuable nutrients and phytochemicals. The valorization of agricultural and food-processing by-products for the recovery of natural functional components has become a priority area in modern food science, biotechnology, and sustainable development. The transformation of these residues into value-added products not only contributes to waste minimization but also supports the development of circular bioeconomy models. In this context, a detailed investigation of the chemical composition of carrot residues is essential for assessing their potential as secondary raw materials for use in functional foods, nutraceuticals, and cosmetic formulations. Moreover, understanding the distribution of lipids and carotenoids in these residues can provide insights into their stability during processing and storage. The aim of this study was to determine the content and compositional profile of lipids and carotenoids present in carrot residues obtained after juice extraction, as well as to evaluate the effect of drying on the preservation and transformation of these compounds. Particular attention was paid to changes in the relative proportions of individual lipid classes and carotenoid fractions. The study also sought to compare the chemical characteristics of fresh and air-dried residues in order to identify optimal conditions for further processing. It was hypothesized that drying may influence both the quantitative and qualitative composition of these bioactive components. Materials and Methods. Fresh carrot (Daucus carota L.) roots of locally cultivated varieties were washed under running water and airdried at room temperature. The roots were grated, and juice was separated from the pulp using a Büchner funnel under vacuum. The resulting solid residue (pomace) was divided into two portions (Samples 1 and 2), each weighing 100 g. The moisture content of Sample 1 was determined by a standard gravimetric method [4] and was found to be 86.93%. Sample 2 was dried in a laboratory oven at a temperature not exceeding 50 °C until an air-dry state was achieved to prevent thermal degradation of thermolabile compounds. Neutral (freely extractable) lipids were isolated from the samples by exhaustive extraction with petroleum ether (boiling range 72–80 °C) using a Soxhlet apparatus and repeated solvent infusion according to established procedures [35]. The obtained lipid extracts were concentrated and used for further analysis. Carotenoids were extracted using organic solvents, quantified spectrophotometrically, and their individual components were separated and identified by chromatographic methods. The classes of compounds present in the neutral lipid fraction were characterized by thin-layer chromatography (TLC). All analyses were performed in triplicate. Figure 1. Soxhlet apparatus RESEARCH AND DEVELOPMENT | VOLUME II | ISSUE 12 | 2025 \ 42 Results and Discussion The results demonstrated that the lipid content in the air-dried carrot residues was 1.3 times higher than that in the fresh (wet) samples, reflecting the concentration effect associated with moisture removal. Similarly, the total carotenoid content in the dried residues was 2.1 times higher than in the wet material. Six carotenoid components belonging to the groups of carotenes and xanthophylls were identified, among which β-carotene predominated as the principal pigment. Analysis of the neutral lipid fraction revealed the presence of six major classes of compounds: hydrocarbons, carotenoids, triacylglycerols, free fatty acids, triterpenols, and sterols. These findings indicate that carrot processing residues retain a complex lipid profile rich in biologically active constituents. The increased relative content of lipids and carotenoids in dried residues suggests that drying is an effective approach for stabilizing and concentrating these valuable compounds. Carotenoids, particularly β-carotene, are known for their antioxidant activity and essential role in human nutrition, making carrot residues a promising raw material for the production of natural pigments and biologically active supplements. In addition, sterols and triterpenols identified in the neutral lipid fraction are of considerable interest for pharmaceutical and cosmetic applications due to their functional properties. To the best of our knowledge, this study represents the first comprehensive characterization of the lipid and carotenoid composition of carrot juice extraction residues. The observed enrichment of lipids and carotenoids in the dried material, together with the diversity of neutral lipid classes, highlights the significant scientific and practical potential of carrot waste as a secondary raw material for the recovery of valuable bioactive substances and the development of value-added products within a sustainable processing framework. Figure 2. Addition of gasoline to a wet sample of crushed carrot roots to extract neutral lipids Figure 3. Extract filtration Figure 4. Combined petrol extracts of lipids from wet crude sample During the first extraction, 300 mL of petroleum ether was added, followed by 250 mL in the second, 170 mL in the third, 160 mL in the fourth, and 100 mL in the fifth extraction step, ensuring exhaustive recovery of freely extractable lipids from the sample. The total duration of lipid extraction from this material was five days, allowing sufficient contact time between the solvent and the solid matrix. After each extraction step, the liquid phase was separated from the solid residue by filtration through filter paper, and all filtrates were subsequently combined. The pooled extract was then concentrated under reduced pressure to remove the solvent prior to further analysis. As a result, the yield of neutral lipids obtained from the wet carrot residue was determined to be 0.48% on a fresh weight basis. The results demonstrate that pre-drying carrot residues to an air-dry state leads to a marked increase in lipid yield as well as a higher carotenoid content compared with wet samples. This effect can be attributed to moisture removal, which concentrates lipophilic compounds and enhances their extractability, as well as to partial disruption of cellular structures during drying. These changes facilitate solvent penetration and improve mass transfer during extraction. Overall, these findings directly support the aim of the present study and confirm that air-drying is a simple and effective pretreatment step for maximizing the recovery of lipids and carotenoids from carrot processing waste, thereby reinforcing its potential for sustainable valorization as a source of biologically active substances in future food, pharmaceutical, and cosmetic applications. TADQIQOT VA TARAQQIYOT | II-JILD | 12-SON | 2025 \ 43 Conclusion This study provides a comprehensive characterization of the lipid and carotenoid composition of carrot (Daucus carota L.) residues generated during juice production and demonstrates their significant potential as a valuable secondary raw material. The results showed that carrot waste retains considerable amounts of biologically active compounds, with β-carotene identified as the dominant pigment in the carotenoid fraction and six major classes of substances detected within the neutral lipid fraction. A key finding of the present work is that pre-drying the residues to an air-dry state leads to a substantial increase in the relative contents of both lipids and carotenoids, with lipid yield and carotenoid levels rising by 1.3and 2.1-fold, respectively, compared with wet samples. This highlights the importance of drying as an effective pretreatment step for enhancing the recovery and stability of lipophilic bioactive compounds. The outcomes of this study not only deepen the understanding of compositional changes occurring in carrot residues during processing but also provide a scientific basis for their valorization in the production of functional food ingredients, nutraceuticals, natural pigments, and formulations for pharmaceutical and cosmetic applications. Overall, the findings support the integration of carrot processing waste into sustainable biorefinery and circular economy approaches, contributing to waste minimization and resource efficiency. Future research should focus on optimizing extraction conditions, evaluating the bioavailability and stability of the recovered compounds, and assessing their safety and functionality in practical applications. RESEARCH AND DEVELOPMENT | VOLUME II | ISSUE 12 | 2025 \ 44 References 1. Mirzayev, B., et al. Technologies for the Utilization of Secondary Raw Materials in the Food Industry. Tashkent: Fan, 2020. 2. Karimova, G. Chemical composition and biological significance of carrots. Journal of Food and Chemistry, No. 2, 2021. 3. Decree of the President of the Republic of Uzbekistan No. PF–5853. Strategy for Agricultural Development for 2020–2030, October 23, 2019. 4. FAO. Food Loss and Waste Reduction in Fruit and Vegetable Processing. Rome: FAO Publications, 2022. TADQIQOT VA TARAQQIYOT | II-JILD | 12-SON | 2025 \ 45 Scientific Review The manuscript entitled “Lipid and Carotenoid Composition of Carrot (Daucus carota L.) Juice Extraction Residues” presents a comprehensive and timely investigation into the chemical characterization and valorization potential of carrot processing by-products. The study addresses an important issue in modern food science and agro-industrial sustainability, namely the effective utilization of secondary raw materials generated during juice production. The topic is highly relevant in the context of growing global interest in circular economy approaches and resource-efficient food processing technologies. The authors provide a well-structured and logically organized manuscript, beginning with a clear introduction that outlines the nutritional significance of carrots and the challenges associated with underutilized processing waste. The rationale for focusing on lipid and carotenoid fractions is convincingly justified, given their well-documented biological activity and industrial importance. The objectives of the study are clearly formulated and aligned with the methodological approach adopted by the authors. The Materials and Methods section is described in sufficient detail to ensure reproducibility of the experiments. The use of Soxhlet extraction for neutral lipids, spectrophotometric determination of carotenoids, and chromatographic techniques for component separation and identification represents a sound and widely accepted analytical strategy. The comparison between wet and air-dried residues is particularly valuable, as it allows assessment of the influence of pretreatment on the recovery of bioactive compounds. The authors’ choice to limit drying temperatures to 50 °C reflects appropriate consideration of the thermal sensitivity of carotenoids. Overall, the experimental design is appropriate for addressing the stated aims of the study. The Results and Discussion section presents the findings in a clear and coherent manner. The demonstration that lipid content increases by 1.3-fold and carotenoid content by 2.1-fold in air-dried residues compared with wet samples is both scientifically sound and practically meaningful. The identification of six carotenoid components, with β-carotene as the dominant pigment, is consistent with existing literature and further confirms the nutritional value of carrot residues. Likewise, the detection of six major classes of compounds within the neutral lipid fraction, including sterols and triterpenols, adds depth to the compositional analysis and highlights the multifunctional potential of the extracted fractions. A notable strength of the manuscript is the authors’ effort to interpret the observed effects of drying not merely as a concentration phenomenon, but also in terms of improved extractability due to structural changes in the plant matrix. This mechanistic perspective strengthens the scientific contribution of the work and provides a useful basis for future optimization studies. The discussion appropriately situates the findings within the broader context of agro-industrial waste valorization and sustainable processing. The conclusions drawn by the authors are well supported by the experimental data. The manuscript convincingly demonstrates that carrot juice extraction residues represent a promising source of biologically active lipids and carotenoids that may be utilized in the development of functional foods, nutraceuticals, and products for pharmaceutical and cosmetic applications. The emphasis on the role of pre-drying as an effective pretreatment step is particularly relevant for potential industrial implementation. In terms of presentation, the manuscript is generally well written, with clear language and appropriate use of scientific terminology. The figures and tables (if included) are presumed to complement the text effectively. Minor editorial polishing may further enhance clarity, but these do not detract from the overall quality of the work. In conclusion, this manuscript represents a solid and meaningful contribution to the fields of food chemistry and sustainable processing. The study is methodologically sound, the results are robust, and the implications are of both scientific and practical importance. I believe that the article meets the standards of an international scientific journal and, having been accepted, will be of interest to researchers and practitioners working on food by-product valorization, bioactive compound recovery, and circular economy strategies in agro-industrial systems. Disclaimer © This scientific review has been prepared by the editorial board of the “RESEARCH & DEVELOPMENT” journal and is intended solely for use within the journal’s internal expert evaluation process and editorial activities. This review is protected by copyright law, and its content may not be distributed, reproduced, or used for commercial purposes without the prior permission of the editorial board. The review has been prepared to assess the scientific quality, content, and methodological aspects of the author’s (authors’) work. It does not represent the personal opinion of the author(s) nor should it be interpreted as the official position of the journal. The editorial board bears no responsibility for the implementation, outcomes, or consequences of the recommendations, conclusions, or comments contained in this review. The review is provided to ensure transparency in the editorial process and to maintain quality control over scientific publications.