Fruits
, 2016, vol. 71(1), p. 57-66
c
Cirad
/
EDP Sciences
2015
DOI:
10.1051
/
fruits
/
2015042
Available online at:
www.fruits-journal.org
O
riginal article
Chemometric characterization of peach, nectarine and plum
cultivars according to fruit phenolic content and antioxidant
activity
Violeta Mitic
, Marija Ilic, Marija Dimitrijevic, Jelena Cvetkovic, Slobodan Ciric
and Vesna Stankov Jovanovic
University of Niš, Faculty of Science and Mathematics, Department of Chemistry, Višegradska 33, 18000 Niš, Serbia
Received 25 March 2015 – Accepted 11 September 2015
Abstract –
Introduction.
Deciduous tree fruits like peach (
Prunus persica
(L.) Batsch var.
persica
), nectarine (
Prunus
persica
(L.) Batsch var.
nucipersica
(Suckow) C.K.Schneid), and especialy plum (
Prunus domestica
L. ssp.
domestica
)
are very common in Serbia. These fruits are known for their nutritional value and therapeutic properties and are valu-
able sources of antioxidants.
Materials and methods.
The goal of this work was to evaluate fruit tissue antioxidant
activity using methanol extracts of 9 peach, 3 nectarine and 7 plum cultivars. The following parameters were mea-
sured: total phenolic content (TPC); antioxidant activity as estimated by radical scavenging activity of (2,2-diphenyl-1-
picrylhydrazyl, DPPH); cation decolorization activity (2,2-azinobis-3 ethylbenxothiazoline-6-sulphonic acid, ABTS);
ferric reducing antioxidant power (FRAP); cupric reducing antioxidant capacity (CUPRAC); and total reducing power
(TRP).
Results and discussion.
Total phenolic contents of the plum cultivars were higher than those of peach and
nectarine and significant positive correlations were recorded between all antioxidant activity assays and total phenolic
contents. Results obtained by principal component analysis (PCA) are in agreement with those obtained by cluster anal-
ysis (CA).
Conclusion.
The selected methods revealed antioxidant activities for all plum cultivars significantly higher
than in the peach and nectarine cultivars. PCA and CA allow grouping the di
ff
erent fruit species based on TPC, DPPH,
ABTS, TRP, FRAP and CUPRAC values.
Keywords:
Serbia
/
peach
/
plum
/
nectarine
/
Prunus
spp.
/
antioxidant activity
/
phenolics
Résumé –
Caractérisation chimiométrique de cultivars de pêches, nectarines et prunes en fonction de la teneur
en composés phénoliques et de l’activité antioxydante de leurs fruits. Introduction.
Les fruits à noyau apparentés
aux pêches (
Prunus persica
(L.) Batsch var.
persica
), nectarine (
Prunus persica
(L.) Batsch var.
nucipersica
(Suckow)
C.K.Schneid), et surtout aux prunes (
Prunus domestica
L. ssp.
domestica
) sont très courants en Serbie. Ces fruits sont
connus pour leur valeur nutritionnelle et leurs propriétés thérapeutiques, et ils sont une source précieuse d’antioxydants.
Matériels et méthodes.
Le but de ce travail était d’évaluer les activités anti-oxydantes des extraits méthanoliques des
fruits de 9 cultivars de pêcher, 3 cultivars de nectarine et 7 cultivars de prunier. Les paramètres suivants ont été mesurés :
le contenu phénolique total (PTC) ; l’activité anti-oxydante par piégeage des radicaux (2,2-diphényl-1-picrylhydrazyl
ou DPPH) ; l’activité de décoloration cationique (acide 2,2-azinobis 3-éthyl-6-benxothiazoline sulfonique ou ABTS) ;
l’activité anti-oxydante ferrique (FRAP) ou cuivrique (CUPRAC) ; et la puissance réductrice totale (TRP).
Résultats
et discussion.
Le contenu total en composés phénoliques des cultivars testés de prune était plus élevé que celui des
cultivars de pêche et de nectarine. Une corrélation positive significative a été enregistrée entre tous les dosages d’activité
anti-oxydante et la teneur totale en composés phénoliques. Les résultats obtenus par analyse en composante principale
(PCA) sont en accord avec ceux obtenus par analyse de clusters (CA).
Conclusion.
Les méthodes analytiques choisies
ont révélé de fortes activités anti-oxydantes pour tous les cultivars de prune, qui sont significativement plus élevées
par rapport aux résultats correspondants pour les cultivars de pêche et de nectarine. La PCA et la CA ont permis le
regroupement des di
ff
érentes espèces fruitières sur la base des valeurs de PTC, DPPH, ABTS, TRP, FRAP et CUPRAC.
Mots clés :
Serbie
/
pêcher
/
prunier
/
nectarine
/
Prunus
spp.
/
activité anti-oxydante
/
composés phénoliques
Corresponding author:
[email protected]
58
Violeta Mitic
et al.
:
Fruits
71 (2016) 57–66
1 Introduction
Balanced diets, including the regular consumption of fruits
play a major protective role against many diseases such as:
di
ff
erent types of cancer, cardiovascular diseases, osteoporosis
and atherosclerosis cellular aging [
1
].
Fruits are valuable sources of nutrients, vitamins, minerals,
dietary fiber, nonessential phytochemicals, water, and espe-
cially an abundance of antioxidant compounds. Antioxidants
are compounds that may inhibit, retard or delay the oxidation
of other molecules by inhibiting the initiation or propagation of
oxidizing chain reactions [
2
]. Phytochemicals that are known
for strong antioxidant activity are polyphenols, carotenoids
and vitamins (A, C, E), all known to be beneficial for improv-
ing human health [
3
].
Peach and nectarine (
Prunus persica
(L.) Batsch vars.
per-
sica
and
nucipersica)
(family
Rosaceae
) represent one of the
most important deciduous fruit crops in the world after apple
and pear. They are summer fruit, widely cultivated in the tem-
perate regions of the world, especially in the Italy, Spain,
France, Greece, United States and China [
4
–
6
].
Prunus persica
is known for its nutritional value and therapeutic properties.
Major constituents of
P. persica
fruit are carbohydrates, or-
ganic acids, minerals and dietary fibers [
7
] which contribute
to its nutritional quality [
8
]. Ripe peach and nectarine fruits
have a white or golden yellowish flesh and a sweet taste due to
lower acidity. Peaches as well as some other
Rosaceae
family
fruits are rich in vitamin A and potassium as well as in organic
acids and sugars [
9
].
Including peaches in the diet can suppress reactive oxy-
gen species (ROS) in human plasma and provide protection
against chronic diseases [
10
]. Peach fruits have laxative prop-
erties and are thus appropriate for preventing constipation and
for the treatment of duodenum ulcers [
7
]. Nectarine and peach
are closely related, di
ff
ering mainly in the fact that nectarine
lacks fruit surface pubescence. Nectarines tend to be some-
what smaller than peaches and some have a firmer texture and
sweeter flavor. Both nectarines and peaches are low in calo-
ries and contain no saturated fats. They are a source of some
of B-complex vitamins including niacin, pantothenic acid, thi-
amin, and pyridoxine. In addition, they contain an appropriate
ratio of minerals and electrolytes such as potassium, iron, zinc,
copper and phosphorus.
Plum fruits (
Prunus domestica
L. ssp.
domestica
) have low
calorie content and a low glycemic index score but relatively
high nutritive value. They contain carbohydrates, first of all
sucrose, glucose and fructose, organic acids,
e.g.
citric and
maleic acids, fibers (pectins), tannins, aromatic substances,
chlorophyll, carotenoids, anthocyanins and enzymes. These
substances determine nutritive value and taste of plums [
12
].
Plum is a fruit rich in phenolic compounds, characterized by
relatively high antioxidant activity, higher than for example or-
ange, apple or strawberries [
13
]. The taste of plum depends
of the relation of sugars and organic acids. Plums are also
rich in many minerals and vitamins (C, A, B1, B2). Ascorbic
acid is the best known antioxidant and an important molecule
in plant tissues that protects plants against oxidative damage
caused by the oxidative metabolites of photosynthesis and aer-
obic processes [
14
].
Plum has high potassium content and an advantageous
sodium
/
potassium ratio [
15
] that slows down the absorption
of carbohydrates, enhances the sensation of satiety, reduces
blood serum triglycerides and homocysteine concentrations
as well as the levels of total cholesterol and its LDL frac-
tion, and increases lipid breakdown in the human organism.
The consumption of plum remains low despite reports that this
tasty fruit with intensive aroma is an important source of com-
pounds with benefits for human health. This might be due to
the lack of maturity of the marketed fruit [
16
].
Peach, nectarine and plum tissues contain ample amounts
of polyphenols, carotenes and anthocyanins [
17
], flavonols
such as quercetin 3-rutinoside, hydroxycinnamates such as
chlorogenic acid and neochlorogenic acid, and flavan 3-ols
such as catechin and epicatechin [
18
,
19
]. The main antho-
cyanins reported in peach and plum were cyanidin 3-glucoside
and cyanidin 3-rutinoside [
18
,
19
], cyanidin 3-acetyl glucoside,
cyanidin 3-galactoside [
19
], peonidin-3-glucoside and peoni-
din derivatives [
18
]. Similar phenolic profiles were detected
for both nectarine and peach, and no di
ff
erences were found
between white-flesh and yellow-flesh peach cultivars [
20
].
Phenolic compounds [
7
,
21
] do not have essential importance
to the peach and nectarine plant itself, but can a
ff
ect the qual-
ity of fruit sensorial-organoleptic attributes (flavor, aroma, and
color), as well as nutritional quality.
The antioxidant content in examined fruits varies greatly
across cultivar type (peach, nectarine or plum) [
22
], grow-
ing practices, geographic location and environmental fac-
tors (water and light availability, soil composition, stresses,
etc.) [
3
,
5
]. Furthermore, as happens for other fruits that are
often picked unripe for commercial handling purposes, peach
antioxidant content may be a
ff
ected by the stage of fruit ripen-
ing at harvest, storage techniques [
12
] and time elapsed be-
tween harvest and consumption [
5
]. Although phenolic com-
pounds have bioactivities which could have a positive impact
on health [
23
], they could provoke undesirable e
ff
ects such
as astringency and bitterness [
1
,
7
,
24
,
25
]. Carotenoids from
peach and nectarine [
26
] especially
β
-carotene, lutein and
β
-
cryptoxanthin [
2
] have a role as pigments but also have a pro-
tective role against oxidative stress in plant cells [
5
].
Published data about the contents of phenolic compounds
and total antioxidant activity of peach and nectarine methanol
extracts are insu
ffi
cient. Taking into account that these natu-
ral antioxidants are multifunctional, the antioxidant capacities
of samples cannot be completely described with one single
method. Also, since the methods are di
ff
erent from each other
in terms of assay principles reaction conditions, and expres-
sion of results, one single method is not enough to show all the
antioxidant proprieties of examined fruits.
The objective of this study was to compare di
ff
erent peach,
nectarine, and plum cultivars to determine fruit phenolic con-
tent and antioxidant capacity. This was done by applying
five widely used spectrophotometric methods: DPPH, ABTS,
FRAP, CUPRAC, TRP and estimating the correlation of an-
tioxidant capacities with total phenolic content. To the authors’
knowledge, clustering of di
ff
erent peach and nectarine species
based on their antioxidant activity and total phenolic content
was done for the very first time.
