nu ien s
A icle
Biological Ac i e Ecuado ian Mango ‘Tommy A kins’
Ing edien s—An Oppo uni y o Reduce Ag owas e
Jenny Ruales 1, Nie es Baenas 2ID , Diego A. Mo eno 2ID , Ca la M. S inco 3ID ,
An onio J. Meléndez-Ma ínez 3and Almudena Ga cía-Ruiz 1,4,*
1Depa men o Food Science and Bio echnology, Escuela Poli écnica Na ional, Qui o 17-01-2759, Ecuado ;
jenny[email p o ec ed]
2Phy ochemis y and Heal hy Foods Lab., Depa men o Food Science and Technology, CEBAS-CSIC,
Campus de Espina do-Edi icio 25, E-30100 Mu cia, Spain; [email p o ec ed] (N.B.);
[email p o ec ed] (D.A.M.)
3
Food Colou & Quali y Lab., Depa men o Nu i ion & Food Science, Uni e sidad de Se illa, Facul ad de
Fa macia, 41012 Se illa, Spain; [email p o ec ed] (C.M.S.); [email p o ec ed] (A.J.M.-M.)
4Labo a o y o Epigene ics o Lipid Me abolism, Mad id Ins i u e o Ad anced S udies (IMDEA)-Food,
CEI UAM + CSIC, 28049 Mad id, Spain
*Co espondence: [email p o ec ed] o almudena.ga [email p o ec ed]; Tel.: +34-91-72-78-100
Recei ed: 17 July 2018; Accep ed: 19 Augus 2018; Published: 21 Augus 2018


Abs ac :
Mango is a comme cially impo an opical ui . Du ing i s p ocessing, peel and seed
ke nel a e disca ded as was e bu hey could be eco e ed as an excellen and cos -e ec i e sou ce o
heal h-p omo ing ing edien s. This s udy aimed o cha ac e ize some o hem, including ca o enoids
like he p o i amin A
β
-ca o ene and lu ein, wi h an in e es beyond i s ole in eye heal h.
O he heal h-p omo ing compounds like ocophe ols and polyphenols we e also e alua ed, as well
as he
in i o
an ioxidan capaci y o mango by-p oduc s. Rega ding isop enoids,
α
- ocophe ol was
mainly ound in he peels and ca o enoids concen a ion was highe in he pulps.
β
-ca o ene was
he mos abundan ca o ene in pulp and seed ke nel, whe eas peel was he only sou ce o lu ein,
wi h iolaxan hin he mos abundan xan hophyll in he di e en mango o gans es ed. Wi h ega d
o polyphenols, peels exhibi ed g ea e a iabili y in i s phenolic composi ion, being he o al con en
up o 85 and 10 imes highe han he pulp and seed ke nels, espec i ely. On he o he hand,
peels also s ood ou o being a e y ich sou ce o mangi e in. Seed ke nels and peels showed highe
an ioxidan capaci y alues han he pulps. These esul s con ibu e o he alo iza ion o mango
by-p oduc s as new na u al ing edien s o he pha ma and ood indus ies.
Keywo ds: mango by-p oduc s; lu ein; β-ca o ene; α- ocophe ol; mangi e in; ood ing edien s
1. In oduc ion
Mango (Mangi e a indica) is conside ed one o he mos consumed esh ui s in he wo ld,
wi h ex ensi e ma ke ing and p oduc ion aking place in 115 coun ies [
1
]. The global a ea o mangoes
ha es ed is app oxima ely 5.41 million hec a es and i s global p oduc ion is 42.66 million me ic ons
(MMT) [
2
]. India, wi h a p oduc ion o 18 MMT, is he wo ld’s la ges mango p oduce , whe eas Mexico
and he Uni ed S a es a e he main mango expo e and impo e , espec i ely [
2
]. The e a e se e al
hund eds o cul i a s o mango; bu by i s long shel li e, excellen a ings in handling and anspo
ole ance he cul i a Tommy A kins is he mos comme cialized [
1
,
3
]. Ecuado , wi h a global a ea o
mangoes ha es ed o 13,300 hec a es and a p oduc ion o 61,300 me ic ons, is he second and six h
mango expo e o USA and o wo ldwide, espec i ely, being an impo an ui in he Ecuado ian
economy [2].
Nu ien s 2018,10, 1138; doi:10.3390/nu10091138 www.mdpi.com/jou nal/nu ien s
Nu ien s 2018,10, 1138 2 o 14
Apa o being consumed esh, abou 20% o mango a e p ocessed o p oduc s such as juices,
desse s, mango jam, among o he s [
4
]. Du ing p ocessing, 33% o he ui is emo ed in he o m
o was e, gene a ing, as a esul , se e al million ons pe yea o mango was e om ac o ies [
4
,
5
].
The mango ac ions disca ded, peel and seed ke nel (35–60% o al weigh o he ui ) a e a sou ce o
pollu ion, among o he easons because hey a e p one o mic obial spoilage causing objec ionable
odo s and en i onmen al p oblems [
1
,
3
]. Howe e , he mango peel and seed ke nel may be in e es ing
because hei high le els o heal h-enhancing subs ances, such as ca o enoids, polyphenols, i amins C
and E and die a y ibe , among o he s [
6
]. The bene i e ec o hese phy ochemicals may be associa ed
wi h hei an ioxidan capaci y, since in he pa hogenesis o many ch onic disease is in ol ed he
o e p oduc ion o oxidan s [
7
]. On he o he hand, a ious s udies ha e desc ibed ha e icien ,
inexpensi e and en i onmen ally iendly use o ag i- ood indus y was e is highly cos -e ec i e and
minimizes en i onmen al impac [
8
,
9
]. In his line, he cha ac e iza ion, eco e y and u iliza ion o
aluable compounds om mango by-p oduc s is an impo an challenge, whose esul would ha e a
signi ican posi i e impac bo h a he en i onmen al le el ( educ ion o pollu ion o mango indus y)
and economically (con ibu ion o mo e sus ainable p oduc ion in he ood and pha maceu ical
indus ies). In addi ion, he e alua ion o mango peels and seed ke nels as a na u al bioac i e
ing edien o he indus y, would ha e a posi i e socio-economical e ec on Ecuado ian mango and
ee ui p oducing a eas, con ibu ing o a educ ion o nu i ional de iciencies and p omo ing heal h
bene i s, as well as educing he en i onmen al implica ions associa ed wi h he mango p ocessing.
In his con ex , he main goal o he p esen wo k was o cha ac e ize and e alua e
Ecuado ian mango by-p oduc s in hei phy ochemical composi ion: wo ypes o isop enoids,
speci ically ca o enoids and
α
- ocophe ol and polyphenols by RRLC (Rapid Resolución
Liquid Ch oma og aphic) and HPLC–DAD–ESI/MS
n
(High-pe o mance Liquid Ch oma og aphic
Diode-a ay de ec o Elec osp ay ioniza ion Mass Spec ome y), espec i ely and hei
o al an ioxidan capaci y by ORAC (Oxygen Radical Abso bance Capaci y) and DPPH
(2,2,-diphenyl-2-pic ylhyd azyl) me hods, as well as by Folin–Ciocal eu assay. These e alua ions we e
ca ied ou o es ablish he po en ial applica ions o hese mango disca ds o non-comme cial p oduc s
(peels and seed ke nels) compa ed wi h he pulp ( he main ac ion consumed o he mango ui s) as
a aluable sou ce o na u al ing edien s and/o addi i es o he pha maceu ical and ood indus y.
2. Ma e ials and Me hods
2.1. F ui Samples
Mangoes (Mangi e a indica L. c . Tommy A kins), we e ob ained in local ma ke s in Qui o
(Ecuado ). The ui s we e selec ed ee o damage. Two kilog ams o samples we e sepa a ed in o
peels, pulps and seed ke nels and s o ed a
−
20
◦
C un il eeze d ying in an Alpha 2–4 LD d ying
mani old (Ma in Ch is Ge ie ocknungsanlagen GmbH, Os e ode am Ha z, Ge many). Then,
samples we e g ound as a ine powde and s o ed a −20 ◦C un il analyses.
2.2. S anda ds, Chemicals and Sol en s
The comme cially a ailable s anda ds (+)-ca echin and u in (Que ce in-3- u inoside) we e
acqui ed om Phy oplan GmbH (Heidelbe g, Ge many). Cyanidin 3-O-glucoside was pu chased
om Polyphenols (Sandnes, No way). The
β
-ca o ene and
β
-c yp oxan hin we e ob ained om
Sigma-Ald ich Chemie GmbH (S einheim, Ge many) and
α
- ocophe ol was pu chased om
Calbiochem (Me ck, Da ms ad , Ge many). Violaxan hin and phy oene we e isola ed om na u al
sou ces by classical ch oma og aphic echniques [
10
]. Lu eoxan hin, neoxan hin and lu ein we e
ob ained as desc ibed by Meléndez-Ma ínez e al. [11].
T olox (6-hyd oxy-2,5,7,8- e ame hylch oman-2-ca boxylic acid) was ob ained om Fluka
Chemika (Neu-Ulm, Swi ze land). The eagen s 2,2-diphenyl-1-pic ylhid acyl adical (DPPH
·
),
monobasic and dibasic sodium phospha e, Folin Ciocal eu’s eagen and luo escein ( ee acid) we e
Nu ien s 2018,10, 1138 3 o 14
pu chased om Sigma–Ald ich (S einheim, Ge many). Finally, o mic acid and sol en s (e hanol,
me hanol, hexane, ace one, diclho ome hane and ace oni ile) we e all o analy ical g ade and we e
ob ained om Me ck (Da ms ad , Ge many).
2.3. Iden i ica ion and Quan i ica ion o Isop enoids (Ca o enoids and
α
-Tocophe ol) by Rapid Resolu ion Liquid
Ch oma og aphy (RRLC)
The ex ac ion and analyses o ca o enoids we e ca ied ou acco ding o he me hod desc ibed
by S inco e al. [
12
]. Mango samples (200 mg) we e ex ac ed wi h 1mL o hexane/ace one (1:1 / )
using a o ex and an ul asonic ba h o 2 min. Then, samples we e cen i uged a 18,000
×
g o
5 min and he colo ed ac ions we e eco e ed. The ex ac ion was pe o med wice mo e un il colo
ex inc ion. Finally, he ca o enoid ex ac s we e concen a ed o d yness in a o a y e apo a o a
empe a u e below 30
◦
C. To ob ain saponi ied ca o enoids, he ex ac s we e ea ed wi h 1000
µ
L
o dichlo ome hane and 1000
µ
L o me hanolic KOH (30% w/ ) o 1 h unde dim ligh and a oom
empe a u e, a e which hey we e washed wi h wa e o emo e any ace o base. The ex ac s
ob ained we e concen a ed o d yness in a o a y e apo a o and edissol ed in e hyl ace a e p io o
hei injec ion in he RRLC sys em. Samples we e ex ac ed and analyzed in iplica e.
The RRLC acquisi ions we e made by using an Agilen 1260 sys em equipped wi h a diode-a ay
de ec o , which was se o scan om 200 o 770 nm and a Po oshell 120 C18 column (2.7
µ
m,
5 cm ×4.6 mm
) (Agilen , Palo Al o, CA, USA) kep a 28
◦
C, acco ding o S inco e al. [
12
]. The injec ion
olume was se a 10–20
µ
L. The mobile phase was pumped a 1 mL/min and consis ed o h ee
sol en s: sol en A, ace oni ile, sol en B, me hanol and sol en C, e hyl ace a e. The linea g adien
elu ion was 0 min, 85% A + 15% B; 5 min, 60% A + 20% B + 20% C; 7 min, 60% A + 20% B + 20% C; 9 min,
85% A + 15% B; 12 min, 85% A + 15% B. Ch oma og ams we e moni o ed a 450 nm. The iden i ica ion
and quan i ica ion o isop enoids we e pe o med by compa ison o hei ch oma og aphic UV– is
spec oscopic cha ac e is ics wi h he s anda ds, as well as by compa ison wi h he ex e nal calib a ion
line calcula ed. Resul s we e exp essed as µg/g d y weigh (D.W.).
2.4. Folin-Ciocal eu Assay
Folin assay was pe o med ollowing he me hod desc ibed by Slinka d and Single on [
13
].
B ie ly, 500
µ
L o he ex ac s, blank o s anda ds we e placed in a 15 mL ube, whe e 2.5 mL o
he Folin–Ciocal eu eagen was added, allowing o eac o 2 min while shaking. Then, 2 mL o
a solu ion o sodium ca bona e (75 g/L) was added and p ope ly mixed. The solu ion was hus
incuba ed 15 min a 50
◦
C. A e ha , he abso bance was measu ed a 750 nm in a spec opho ome e
(Shimadzu UV-160A, Kyo o, Japan). Gallic acid was used as a s anda d (10–90 mg/L) and he esul s
we e exp essed as mg o gallic acid equi alen s (GAE) pe g am.
2.5. Iden i ica ion and Quan i ica ion o Phenolic Compounds by HPLC–DAD–ESI-MSn
Phenolic compounds we e ex ac ed and analyzed ollowing he p o ocol and me hod o
Gi onés-Vilaplana e al. [
14
]. B ie ly, samples we e ex ac ed wi h MeOH 70% using he ul asound
echnology and kep a 4
◦
C o e nigh . Then, samples we e il e ed and he iden i ica ion o
phenolic compounds was ca ied ou ollowing hei MS2 agmen a ions by an HPLC–DAD–ESI-MS
n
,
cons i u ed by an Agilen se ies model HPLC (High-pe o mance Liquid Ch oma og aphic) 1100 wi h
a pho odiode a ay de ec o and a mass spec ome e de ec o in se ies (model G2445A) equipped
wi h an elec osp ay ioniza ion in e ace (Agilen Technologies, Waldb onn, Ge many). The ioniza ion
condi ions we e selec ed acco ding o hose desc ibed in he me hod, co e ing an m/z ange om
100 o 1200. The acquisi ion o he mass spec ome y da a (MS
n
) was pe o med in he nega i e
ioniza ion mode o la onoids, excep o an hocyanins, whe e he posi i e ioniza ion mode was
used. The quan i ica ion equipped wi h a Luna C18 column (25 cm
×
0.46 cm, 5
µ
m pa icle size)
(Phenomenex, Maccles ield, UK) using he acquisi ion condi ions desc ibed be o e. Fla an-3-ols
we e quan i ied using he ex e nal s anda d (+)-ca echin a 280 nm, la onols a 360 nm using he
Nu ien s 2018,10, 1138 4 o 14
s anda d u in (que ce in-3- u inoside) and he an hocyanins by using cyanidin 3-O-glucoside a
520 nm. Samples we e ex ac ed and analyzed in iplica e. Resul s we e exp essed as µg/g D.W.
2.6. An ioxidan Capaci y
The an ioxidan capaci y was e alua ed using he me hods DPPH
·
and ORAC, bo h adap ed
o a mic oscale and pe o med using 96-well mic o pla es (Nunc, Roskilde, Denma k), which we e
measu ed using an In ini e
®
M200 mic opla e eade (Tecan, G ödig, Aus ia). The powe o sca enge
DPPH adicals we e de e mined acco ding o Mena e al. [
15
], b ie ly, 2
µ
L o he co esponding dilu ed
sample was added o he wells con aining 250
µ
L o DPPH
·
dissol ed in me hanol up o abso bance ~1.
Then, he pla e was shaken and le o 50 min a 37
◦
C, hus, he a ia ion in abso bance was measu ed
a 515 nm. Rega ding he ORAC me hod and acco ding o Ou e al. [
16
], 25
µ
L o he p ope ly dilu ed
sample was added o 150
µ
L o luo escein (1
µ
M) and, a e 30 min o incuba ion, 25
µ
L o he adical
AAPH (2,2
0
-azobis(2-me hyl-p opionamidine)-dihyd ochlo ide) (250 mM) was added o he wells.
Resul s we e s udied by measu ing he a ia ion in luo escence each 2 min du ing 120 min o eac ion
wi h he adical. T olox was used as a s anda d in bo h me hods, ollowing he same p ocedu e as wi h
he samples. Resul s we e exp essed as mmol T olox/100 g D.W.
2.7. S a is ical Analysis
All assays we e conduc ed in iplica e. The da a we e p ocessed using he so wa e S a g aphics
Cen u ion e sion 16.1.18 (S a g aphics.Ne , Mad id, Spain). All alues we e subjec ed o analysis o
a iance (ANOVA) wi h a 95% con idence le el. Pea son’s co ela ion coe icien s we e also calcula ed
o co obo a e ela ionships among he selec ed pa ame e s.
3. Resul s and Discussion
The i s s ep o es ablish he po en ial applica ions o he mango by-p oduc s, peels and seed
ke nels, as a aluable sou ce o na u al ing edien s and/o addi i es o he pha maceu ical and ood
indus y is c ucial o cha ac e ize he phy ochemical composi ion wi h e icien echniques o he
iden i ica ion and quan i a ion o he nu ien s and compounds o in e es . Bea ing his in mind,
di e en ch oma og aphic me hods we e used o cha ac e ize he isop enoids, especially ca o enoids
and α- ocophe ol and he phenolic composi ion o mango by-p oduc s.
3.1. Isop enoids: Ca o enoids and α-Tocophe ol
Many s udies ha e e alua ed he ca o enoid ac ion o mango pulps bu no peels and seed
ke nels. In his sense, his s udy p o ides in o ma ion on he cha ac e iza ion o ca o enoid in
non-edible pa s o he mango. In pa icula , six ca o enoids (4 xan hophylls and 2 ca o enes) we e
iden i ied and quan i ied in he di e en mango o gans es ed (peels, pulps and seed ke nels) (Table 1).
The ca o enoid composi ion, bo h quali a i e and quan i a i e, showed di e ences be ween he
di e en mango o gans es ed, which is in line wi h da a p e iously desc ibed in he li e a u e [
17
].
Violaxan hin and
β
-ca o ene s ood ou as he only wo ca o enoids p esen in he di e en mango
ac ions es ed (Table 1). Rega ding pulps and seed ke nels, he mos abundan ca o ene was
β
-ca o ene, whe eas he mos impo an xan hophyll was iolaxan hin (Table 1). This is compa able
wi h he esul s epo ed by O nelas-Paz e al. [
18
] in se en Mexican mango cul i a s. Mo eo e ,
se e al au ho s ha e desc ibed
β
-ca o ene as he mos p edominan ca o enoid in Aus alian and
Taiwanese mango pulps [
19
,
20
]. In e ms o biological e ec s,
β
-ca o ene is conside ed, heo e ically,
he ca o enoid wi h he highes p o i amin A ac i i y [
21
] while he heal h bene i s o iolaxan hin
ha e ye o be es ablished [
17
]. Wi h ega d o mango peels, lu ein highligh ed as majo ca o enoid
(Table 1). This ag ees wi h he esul epo ed by Ajila e al. [
22
] in peels Bandami mango a ie y.
Lu ein is an essen ial nu ien wi h heal h p omo ing e ec s, especially o eye heal h. In his line,
he use o lu ein in he o mula ion o nu i ional supplemen s ha e gained inc easing popula i y o
he p e en ion o age- ela ed macula degene a ion, as well as o i s an ioxidan p ope ies, a e he
Nu ien s 2018,10, 1138 5 o 14
public awa eness o i s po en ial o p e en he disease [
23
]. Thus, he pa icula in e es o he
indus y, especially pha maceu ical, in he sea ch o new cos -e ec i e sou ces o lu ein as could be
mango peels. In addi ion o i s e ec s on he e ina, i has ecen ly been epo ed he accumula ion
o lu ein in b ain, being i s con en in neu al issue posi i ely co ela ed wi h cogni i e unc ion,
which has in ensi ied in e es in iden i ying unc ions o lu ein in his o gan [
24
]. Fu he mo e, lu ein is
a na u al colo an , so he mango peels could be employed as addi i e in he indus y such as ood,
cosme ic and nu aceu ical.
Table 1.
Isop enoid, ca o enoids and
α
- ocophe ol, composi ion in mango o gans (peels, pulps and
seed ke nels).
Concen a ion (µg/g D.W.)
Peel Pulp Seed Ke nel
Ca o enoids
Violaxan hin * 1.58 b±0.13 3.97 a±0.19 0.18 c±0.02
Lu ein 3.26 ±0.19 - -
Lu eoxan hin - 1.69 a±0.08 0.16 b±0.04
β-c yp oxan hin - 2.72 ±0.04 -
β-ca o ene 2.78 b±0.05 4.86 a±0.01 0.50 c±0.01
Phy oene - 1.23 a±0.01 0.23 b±0.03
∑ca o enoids 7.62 b±0.37 14.47 a±0.33 1.07 c±0.10
α- ocophe ol 10.20 a±1.13 0.39 b±0.21 -
* In peel, he concen a ion o ioloxan hin co esponds o iolaxan hin + neoxan hin;
a–c
Mean alues wi h di e en
le e on he igh in he same ow indica e s a is ically signi ican di e ences among he h ee ea men s (p< 0.05).
On he o he hand, he esul s ob ained on he quali a i e and quan i a i e cha ac e iza ion o
ca o enoid showed di e ences wi h he esul s epo ed in o he mango cul i a s (Kei , A aul o,
Haden and Ken ) om Mexico, B azil, Taiwan [
18
,
20
,
25
]. These di e ences could be due o ac o s
such as gene ics, ag icul u al and indus ial p ac ices, empe a u e, ha es , ma u i y, among o he s,
which can modi y he composi ion o ca o enoids [3,17].
The o al con en o ca o enoids (TCC), e alua ed as he sum o he con en o indi idual pigmen s,
showed signi ican di e ences be ween he di e en ac ions o mango. The mango pulps showed he
highes con en (Table 1). TCC ob ained in he pulps (14.47
µ
g/g) is wi hin he ange desc ibed in o he
se e al mango cul i a s (9.0 o 92
µ
g/g) [
26
]. Al hough he pulps showed he highes TCC, he esul
also e lec ed ha mango by-p oduc s could be a aluable sou ce o ca o enoid, especially mango
peels. TCC ob ained in mango peels (7.62
µ
g/g) is highe o compa able han TCC alues epo ed
in opical ui s (Table 2), which e lec s ha mango peels a e no only a disposable was e bu an
ex ao dina y sou ce na u al o ca o enoids. The use o mango peels o e s a window o oppo uni y
o con igu ing al e na i e ood supply chains. The aw ma e ial is aluable in e ms o nu i ional
and unc ional p ope ies and besides, he use o his side s eam is o g ea in e es om he poin o
iew o en i onmen al conce ns and o ood and nu i ion pu poses.
Table 2. Ca o enoid concen a ion in opical ui s.
Ca o enoid Concen a ion (µg/g D.W.)
Eugenia s ipi a a 8.06 [27]
Solanum qui oense 7.94 [28]
Ananas comosus 4.97 [29]
Psidium guaja a 6.04 [29]
Ca ica papaya 7.93−51.34 [30]
In ela ion o
α
- ocophe ol, i is an an ioxidan wi h an e ec i e chemop o ec an agen agains
lipid oxida ion. In he p esen s udy, he
α
- ocophe ol was de ec ed and quan i ied in peels and

Nu ien s 2018,10, 1138 6 o 14
pulps bu no in seed ke nels. Conc e ely, i s con en was 26 imes g ea e in peels han pulps
(Table 1).
Abbasi e al. [31]
also de ec ed highe con en o
α
- ocophe ol in peels han pulps in
nine mango cul i a s om China.
α
- ocophe ol amoun in mango pulps was highe han ha
desc ibed by Bu ns e al. [
32
] (0.05
µ
g/g) in mango om Cos a Rica, in ag eemen wi h O nelas-Paz
e al. [
18
] (
0.2–0.5 µg/g
) in se en Mexican mango cul i a s bu lowe han he con en desc ibed by
Vilela e al. [33]
(
12–94 µg/g
) and Gong e al. [
34
] (2.0
µ
g/g) in wel e Po uguese mango cul i a s
and in mango om China, espec i ely. As polyphenols and ca o enoids, he
α
- ocophe ol amoun
depends on he geno ype, he en i onmen al ac o s and analy ical me hods, among o he ac o s [
35
],
which explains he di e ences obse ed among he esul s ob ained in his s udy and o he s. On he
o he hand,
α
- ocophe ol concen a ion ob ained in peels was g ea e han obse ed in some exo ic
ui s such as d agon ui (4.5
µ
g/g), du ian (3.6
µ
g/g) and papaya (2.6
µ
g/g) [
35
]. This esul e lec s
ha mango peels could be exploi ed as na u al an ioxidan in cosme ic (i.e., an i-aging p oduc s),
pha maceu ical and ag o-indus y.
3.2. Cha ac e iza ion o he Phenolic Composi ion
3.2.1. Iden i ica ion o Phenolic Compounds
Se en een phenolic compounds we e sepa a ed and en a i ely iden i ied as p ocyanidins (1–3),
an hocyanins (4, 6), xan hones (5, 7, 9, 16, 17) and la onols (8, 10–15) by HPLC–DAD–ESI/MS
n
,
which a e shown in Table 3. In addi ion, he sepa a ion o polyphenolics in mango peel is shown
in Figu e 1.
Nu ien s 2018, 10, x FOR PEER REVIEW 6 o 14
geno ype, he en i onmen al ac o s and analy ical me hods, among o he ac o s [35], which
explains he di e ences obse ed among he esul s ob ained in his s udy and o he s. On he o he
hand, α- ocophe ol concen a ion ob ained in peels was g ea e han obse ed in some exo ic ui s
such as d agon ui (4.5 µg/g), du ian (3.6 µg/g) and papaya (2.6 µg/g) [35]. This esul e lec s ha
mango peels could be exploi ed as na u al an ioxidan in cosme ic (i.e., an i-aging p oduc s),
pha maceu ical and ag o-indus y.
3.2. Cha ac e iza ion o he Phenolic Composi ion
3.2.1. Iden i ica ion o Phenolic Compounds
Se en een phenolic compounds we e sepa a ed and en a i ely iden i ied as p ocyanidins (1–3),
an hocyanins (4, 6), xan hones (5, 7, 9, 16, 17) and la onols (8, 10–15) by HPLC–DAD–ESI/MS
n
, which a e
shown in Table 3. In addi ion, he sepa a ion o polyphenolics in mango peel is shown in Figu e 1.
Figu e 1. Typical ch oma og am o mango o gans (e.g., peels), egis e ed a 360 nm (A) and 520 nm
(B) o he iden i ica ion; Ex ac ed Ion Ch oma og am o (M)
−
o pa en al ions (C) o he phenolic
compounds in he mango samples is also included. Fo he compound assignmen numbe s, please
see Table 3.
Figu e 1.
Typical ch oma og am o mango o gans (e.g., peels), egis e ed a 360 nm (
A
) and
520 nm (
B
) o he iden i ica ion; Ex ac ed Ion Ch oma og am o (M)
−
o pa en al ions (
C
) o he
phenolic compounds in he mango samples is also included. Fo he compound assignmen numbe s,
please see Table 3.
Nu ien s 2018,10, 1138 7 o 14
Table 3. Ten a i e iden i ica ion o phenolic compounds in mango o gans (peels, pulps and seed ke nels) by HPLC–DAD–ESI-MSn.
Peak Numbe R (min) DAD (Max. Abs.) λnm (M)−F agmen Ions (MSn) Phenolic Compounds (Ten a i e Iden i ica ion) Peels Pulp Seed Ke nels
1 7.2 280 423 303, 289 P ocyanidin (ca echin de i a i e) √- -
2 10.5 280 575 423, 289 P ocyanidin dime √
3 15.9 280 559 407,289 (Epi)a zelechin-(epi)ca echin dime √- -
4 19.2 280, 520 - - Uniden i ied an hocyanin √- -
5 21.5 330,360 421 403, 331, 301, 258–259 Mangi e in √ √ √
6 25.7 280, 520 - - Uniden i ied an hocyanin √- -
7 29.5 360 573 421, 403, 331, 301 Mangi e in galla e √- -
8 34.4 360 599 285 Kaemp e ol de i a i e √- -
9 36.3 360 573 421, 403, 331, 301 Mangi e in galla e √- -
10 37.1 360 463 301 Que ce in galac oside √- -
11 38.5 360 463 301 Que ce in glucoside √- -
12 40.8 360 433 301 Que ce in xyloside √- -
13 42.5 360 433 301 Que ce in a abinopy anoside √- -
14 44.4 360 433 301 Que ce in a abino u anoside √- -
15 45.8 360 447 301 Que ce in hamnoside √- -
16 47.4 330,360 421 403, 373, 331, 301 Mangi e in (isome ) √- -
17 48.2 360 573 421, 403, 331, 301 Mangi e in galla e (isome ) √- -
R : e en ion ime; DAD: dyode-a ay de ec o .
Nu ien s 2018,10, 1138 8 o 14
P ocyanidins
Peaks 1 and 2 showed he MS spec a o p ocyanidin dime s wi h molecula in ac ions a m/z
o 423 and 575, espec i ely and a cha ac e is ic dep o ona ed molecula ion in MS2 o m/z289 ha
co esponds o a (epi)ca echin. I is impo an o highligh ha bo h phenolic compounds had ne e
been de e mined in mango peels be o e. On he o he hand, peak 3 was iden i ied as a p opela gonidin
dime due o i s molecula ion (M–H) a m/za 559–560 and i s MS2/MS3 agmen ions m/z407
and 289, co esponding p obably o (epi)a zelechin-(epi)ca echin. These p ocyanidins we e only
cha ac e ized in mango peels.
The compounds 4 and 6 exhibi ed peak abso p ion maximum a ~280 nm and ~520 nm
wa eleng hs, cha ac e is ic o an hocyanins bu in ex emely low concen a ion ha did no allow
he en a i e iden i ica ion o he compounds o he isola ion o hei aglycones in he (M)
−
and i s
co esponding MS/MS agmen a ion expe imen s. These compounds we e de ec ed in mango peels
bu no in pulps and seed ke nels.
Xan hones
Peak 5 showed a molecula anion a m/z421, being he e o e en a i ely assigned as mangi e in.
Peaks 7 and 9, wi h a co esponding m/zion o 573 (M)
−
and cha ac e is ic MS/MS agmen a ion,
we e en a i ely iden i ied as mangi e in galla es [
36
]. In he las pa o he ch oma og am, iny peaks
o possible isome s o mangi e in (peak 16) and mangi e in galla e (peak 17) we e also de ec ed in he
MS/MS expe imen s. These compounds, wi h excep ion o mangi e in, we e only de ec ed in peels.
Mangi e in was also he unique xan hone de ec ed in he pulps o he cul i a Haden, and in he seed
ke nels o he cul i a Ubá, bu he pulps o he cul i a Ubáwe e cons i u ed by a g ea e numbe o
xan hones [37]. This esul e lec s he a iabili y o he phenolic composi ion in he mango.
Fla onols
Peak 8 was iden i ied as kaemp e ol de i a i e acco ding o hei UV spec a and MS
agmen a ion leading o he kaemp e ol aglycone a m/z285 in nega i e mode [
38
]. Wi h ega d
o compounds 10–14, hey we e iden i ied as que ce in glycosides based on hei UV-Vis da a and
cha ac e is ic mass spec a and elu ion o de [
39
] (Table 3). In he que ce in glycosides, he mos
abundan agmen ion in MS2/MS3 was m/z301 ha co esponds wi h he adical anion o he
aglycone que ce in. Peaks 10 and 11 displayed iden ical (M)
−
ion, m/z463 and could be assigned as
que ce in-galac oside and que ce in glucoside, espec i ely. The o ma ion o he ion a m/z433 [M]-
as he main agmen ions in he peaks 12, 13 and 14 e ealed he p esence o h ee di e en que ce in
pen osides and ecognized as que ce in xyloside (12), a abinopy anoside (13) and a abino u anoside
(14), espec i ely. Finally, he occu ence o an ion (M–H)
−
a m/z447 in he compound 15 indica ed
he exis ence o a que ce in hamnoside. These la onoids we e obse ed in mango peels bu no in
pulps and seed ke nels. This ag ees wi h p e iously epo ed da a by Be a dini e al. [
40
] in cul i a
Tommy A kins and Gómez-Ca a aca e al. [41] in Kei mango.
These esul s e lec ed ha he phenolic p o ile o peels was di e en o he p o iles ob ained
in pulps and seed ke nels (Table 3). This ag ees wi h in o ma ion p e iously epo ed in he
li e a u e, whe e i is indica ed ha o di e en mango phenolics di e in he di e en plan pa s [
42
].
In pa icula , in his s udy he peels showed a highe numbe o phenolic compounds han pulps and
seed ke nels. This is in acco dance wi h esul s p e iously desc ibed in mango [37,43].
3.2.2. Quan i ica ion o Phenolic Compounds
The esul s o he quan i ica ion o phenolic compounds in mango a e shown in Table 4.
Mangi e in was he p edominan phenolic compound in he h ee mango ac ions bu i s quan i y was
di e en in each o gan. In pa icula , mango peels p esen ed he highes concen a ion (2500
µ
g/g D.W.)
ollowed by seed ke nels and pulp (Table 4). This esul e lec ed ha non-edible pa s o he mango
Nu ien s 2018,10, 1138 9 o 14
ui a e good sou ces o mangi e in. Simila esul s we e ob ained by Luo e al. [
43
], Gómez-Ca a aca
e al. [
41
] and Ribei o e al. [
37
] in 11 Chinese cul i a s, cul i a Kei and cul i a Ubáo mango,
espec i ely. Howe e , he mangi e in concen a ions ob ained we e di e en o he desc ibed
by o he au ho s in cul i a Tommy A kins (peels: 1190.9–1690.4
µ
g/g; pulps: 2.2
µ
g/g) [
36
,
43
]
and cul i a s A aul o, Kei , Van Dyke and Ubá, among o he s (peels: 62.3–21530
µ
g/g; pulps:
no de ec ed-200
µ
g/g; seed ke nels: aces-2340
µ
g/g) [
37
,
41
,
43
–
45
]. This ag ees wi h da a p e iously
epo ed in he li e a u e, whe e i has been epo ed ha ac o s such as cul i a , en i onmen ,
ha es s age, ma u i y as well as he me hod ex ac ion, among o he ac o s, ha e an e ec on he
phenolic composi ion [
3
,
19
,
44
,
45
]. Rega ding he mangi e in biological e ec s, his phenol possesses
an an ioxidan capaci y highe han o he na u al an ioxidan s like i amin C and E. In his line,
his phenolic compound could be used as a ood p ese a i e. In addi ion, mangi e in has a special
pa icula in e es o he pha macological indus y by i s cance chemop e en i e po en ial [41].
Table 4. Concen a ion o phenolic composi ion in mango peel, pulp and seed ke nel.
Peak Phenolic Compounds Concen a ion (µg/g D.W.)
Peel Pulp Seed Ke nel
1 P ocyanidin (ca echin de i a i e) 560 ±60 - -
2 P ocyanidin dime <LOQ - -
3 Epia zelechin-epica echin dime 600 ±60 - -
4 Uniden i ied an hocyanin <LOQ - -
5 Mangi e in 2500 a±320 50 c±20 430 b±90
6 Uniden i ied an hocyanin 30 ±0 - -
7 Mangi e in galla e <LOQ - -
8 Kaemp e ol de i a i e <LOQ - -
9 Mangi e in galla e <LOQ - -
10 Que ce in-galac oside 220 ±20 - -
11 Que ce in glucoside 180 ±10 - -
12 Que ce in xyloside <LOQ - -
13 Que ce in a abinopy anoside 80 ±10 - -
14 Que ce in a abino u anoside 50 ±0 - -
15 Que ce in hamnoside 50 ±0 - -
16 Mangi e in (isome ) <LOQ - -
17 Mangi e in galla e (isome ) <LOQ - -
∑phenolic compounds 4270 a±480 50 c±20 430 b±90
LOQ: limi o quan i ica ion;
a–c
Mean alues wi h di e en le e on he igh in he same ow indica e s a is ically
signi ican di e ences among he h ee ea men s (p< 0.05).
Rega ding he p esence o p ocyanidins, hese compounds we e ound only in he peel and wo
o hem, a ca echin de i a i e (560
µ
g/g D.W.) and epia zelechin-epica echin (600
µ
g/g D.W.) dime s,
cons i u ed he mos abundan phenolic compounds a e mangi e in (Table 4). These compounds,
accoun ing o he 25% o o al phenolic compounds, ha e been desc ibed in mango peels o he
i s ime. Acco ding o o he au ho s, hese low-molecula weigh p ocyanidins ha e been desc ibed
as in e es ing because o hei po en an ioxidan capaci y and possible p o ec i e e ec s on human
heal h [
42
,
46
], especially because dime s can be abso bed in ac in he in es inal ac [
47
] and ha e
ecen ly shown o p omo e he g ow h o Bi idobac e ium
in i o
[
48
]. As na u al an ioxidan s and
an imic obials, p oan hocyanidins can be also used in he indus y as a p ese a i e, o s abilize ood
colo s, o p e en ancidi y due o oxida ion o unsa u a ed a s and o a oid he g ow h o bac e ia
and molds [49].
On he o he hand, la onol glycosides ob ained in mango peel we e iden i ied as que ce in
glycosides, being que ce in galac oside and que ce in glucoside he mos abundan (Table 4),
acco ding o he li e a u e [
36
,
41
,
50
]. Que ce in glycosides biological e ec s a e mainly associa ed
o hei an ioxidan capaci y which could be exploi ed as a ood p ese a i e and s abilize in
he ag o-indus y, as well as in he de elopmen o new d ugs in he pha maceu ical indus y,
among o he s [51].