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Phytochemicals of lentil (Lens culinaris) and their antioxidant and anti-inflammatory effects

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Abstract

Lentils contain a plethora of bioactive phytochemicals such as extractable and insoluble-bound phenolics, carotenoids, tocopherols, saponins, phytic acid, and phytosterols, which have been increasingly attributed to the health benefits of lentil consumption in the diet. The concentration and stability of these phytochemicals in lentils may be affected by several processing parameters including different thermal processing, exogenous enzyme treatment and germination. Consumption of lentils has been associated with the risk reduction of many diseases due to the potential antioxidant activity and anti-inflammatory potential of phytochemicals in lentils. This mini review is intended to provide most current information on the phytochemical composition of lentils, and the potential antioxidant and anti-inflammatory properties of these compounds.
Copyright: © 2018 International Society for Nutraceuticals and Functional Foods.
All rights reserved. 93
Review J. Food Bioact. 2018;1:93–103
Journal of
Food Bioactives International Society for
Nutraceuticals and Functional Foods
Phytochemicals of lentil (Lens culinaris) and their antioxidant and
anti-inammatory effects
Bing Zhanga, Han Penga, Zeyuan Denga and Rong Tsaob*
aState Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
bGuelph Research & Development Centre, Agriculture and Agri-Food Canada, 93 Stone Road West, Guelph, ON N1G 5C9, Canada
*Corresponding author: Rong Tsao, Guelph Research & Development Centre, Agriculture and Agri-Food Canada, 93 Stone Road West,
Guelph, ON N1G 5C9, Canada. Tel: +1 226-217-8108; Fax: +1 226-217-8183; E-mail: rong.cao@agr.gc.ca
DOI: 10.31665/JFB.2018.1128
Received: January 18, 2018; Revised received & accepted: February 26, 2018
Citation: Zhang, B., Peng, H., Deng, Z., and Tsao, R. (2018). Phytochemicals of lentil (Lens culinaris) and their antioxidant and anti-
inammatory effects. J. Food Bioact. 1: 93–103.
Abstract
Lenls contain a plethora of bioacve phytochemicals such as extractable and insoluble-bound phenolics, carote-
noids, tocopherols, saponins, phyc acid, and phytosterols, which have been increasingly aributed to the health
benets of lenl consumpon in the diet. The concentraon and stability of these phytochemicals in lenls may
be aected by several processing parameters including dierent thermal processing, exogenous enzyme treat-
ment and germinaon. Consumpon of lenls has been associated with the risk reducon of many diseases due
to the potenal anoxidant acvity and an-inammatory potenal of phytochemicals in lenls. This mini review
is intended to provide most current informaon on the phytochemical composion of lenls, and the potenal
anoxidant and an-inammatory properes of these compounds.
Keywords: Lentils; Phytochemicals; Phenolics; Carotenoids; Antioxidants; Anti-inammatory.
1. Introducon
Legumes, commonly referred to as “pulses”, are one of the most
extensively cultivated crops throughout the world and are typically
marketed as dry products (Schneider, 2002). They are consumed
as a basic staple food in many countries, providing ideal protein,
carbohydrates (including dietary bers), fatty acids, minerals, and
vitamins complementary to cereal-based diets (Gumienna et al.,
2009; Marathe et al., 2011). Pulses are dened by the Food and
Agriculture Organization (FAO) of the United Nations as grain
legumes harvested only for their seeds (Mudryj et al., 2012). FAO
lists eleven primary pulses including lentils, and excludes legumi-
nous seeds used primarily for oil extraction,such as soybeans and
groundnuts, or those consumed in immature form as vegetables,
such as green beans and green peas (Dahl et al., 2012). Lentils
(Lens culinaris) have been gaining increasing attention for their
nutritive value as human diet. It is sometimes called “poor man’s
meat”, which originated in ancient Europe (Bhatty, 1988). For
these reasons, lentils have long been recognised as an inexpensive,
excellent alternative to animal proteins, and are considered as a
potential whole food source for people affected by micronutrient
malnutrition (Thavarajah et al., 2009). Lentil crop was rst intro-
duced into southern Manitoba and Saskatchewan in Canada during
the grain surplus years of the early 1970’s due to favorable price
compared with depressed cereal prices (Bhatty, 1988). Canada is
by far the world’s largest lentil exporter to the global marketplace,
selling to over 100 countries each year, and produces about 25%
of the total world output (Thavarajah et al., 2009). The most com-
monly grown lentil cultivars are the large green “Laird” cultivar
and the red lentil (http://www.pulsecanada.com/food-health/what-
is-a-pulse/lentil).
In recent years, many studies have shown potential health ben-
ets of pulses, including lentils, beyond satisfying basic nutrient
requirements for humans (Rochfort and Panozzo, 2007). Epide-
miological and interventional studies suggest that pulse consump-
tion is inversely associated with the incidence of several chronic
diseases, such as coronary heart disease, type II diabetes mellitus,
cardiovascular diseases, cancer and aging (Amarowicz and Pegg,
Journal of Food Bioactives | www.isnff-jfb.com
94
Phytochemicals of lentil (Lens Culinaris)Zhang et al.
2008; Villegas et al., 2008). Some of these purported benets of
consuming a pulse-based diet have been attributed to their high
content of phytochemicals that exert antioxidant and anti-inam-
matory activity in vitro and in vivo (Amarowicz et al., 2004; Xu
and Chang, 2012). However, the consumption of pulses like len-
tils is limited in western countries, with only about one in eight
people consuming pulses on a daily basis (Mudryj et al., 2012),
due to traditional eating customs, lack of consumer education and
understanding on the nutritional values, processing techniques and
available diversied food products. Despite this, incorporation of
pulses into western diets has been highly recommended for con-
sumers to receive maximum health benets (Aguilera et al., 2010).
In order to heighten public awareness of the nutritional benets of
pulses as part of sustainable food production aimed towards food
security and nutrition, FAO has declared 2016 the International
Year of Pulses (IYP) (http://www.fao.org/pulses-2016/en/).
Macronutrients such as carbohydrates and proteins are the main
components of lentils, and current research suggests protein hydro-
lysates and peptides may be responsible for some of the observed
health benets, and dietary bres and their colonic fermentation
products i.e. short chain fatty acids (SCFA) may be a contributing
factor to gut and colon health. Micronutrients such as phenolics
have also shown strong antioxidant and anti-inammatory effects.
However, despite these ndings, there is no consensus on the ex-
act bioactive component(s) in lentils that contribute to the health
benets. There is a need for a comprehensive overview on the pos-
sible bioactive components in lentils. Inammation, especially low
grade inammation, is the root cuase of oxidative stress induced
chronic diseases. Food components with antioxidant and anti-in-
ammatory activities therefore are naturally targets of the health
benets of lentils. The present contribution intends to provide a
review of the recent advances in the phytochemicals of lentils
and their antioxidant and anti-inammatory effects and how they
might contribute to reduction in human health risks.
2. Phytochemicals in lenls
In general, phytochemicals could be broadly dened as all plant
derived chemicals including macronutrients such as carbohy-
drates, lipids and proteins. However, in the present contribution,
the term “phytochemicals” refers to those small non-essential bio-
active compounds or secondary metabolites that occur naturally in
plants. These phytochemicals such as avonoids and carotenoids
are usually responsible for the color and other organoleptic proper-
ties of food, but also have other signicant biological activities.
Lentils have been reported to contain an array of different phyto-
chemicals such as phenolics, condensed tannins, carotenoids, toco-
pherols, saponins, phytic acid, and phytosterols, making them the
major sources for phytochemicals in the diet. Table 1 summarizes
the different phytochemicals reported for lentils.
2.1. Extractable phenolics
Polyphenolic compounds are perhaps the most diverse group of
phytochemicals that are known for their various biological proper-
ties. To date, more than 8,000 polyphenolic substances have been
identied. These polyphenols can be classied into sub-groups
such as phenolic acids and avonoids according to their molecular
structures. Phenolic acids are simple phenolics that can be further
divided into hydroxybenzoic acid derivatives and hydroxycin-
namic acid derivatives. Flavonoids are the most important phe-
nolic subclass, characterized by a C6–C3–C6 backbone structure.
Flavonoids can be further classied into different sub-groups of
avan-3-ols, avonols, avones, avanones, anthocyanidins and
isoavones, and oligomers such as proanthocyanidins. The phe-
nolic compounds in plant are conventionally extracted by ethyl or
methyl alcohols, acetone or their aqueous mixtures, which is only
efcient in extracting soluable phenolics., leaving behind other
phenolics that exist in the bound form. For this reason, the major-
ity of the reported measurement of phenolics in food samples is
conned to the soluble or extractable phenolic fraction.
Lentils are a signicant dietary source of these extractable phe-
nolics. The major phenolic compounds found in lentils include
sub-classes of phenolic acids, avan-3-ols, condensed tannins
(proanthocyanidins), anthocyanidins, avonols, stilbenes, avones,
and avanones. Lentil was reported to have the highest total phe-
nolic content (TPC) of 7.53 mg gallic acid equivalents (GAE)/g
dry weight (DW) among 8 different types and varieties of pulses,
as well as 2.21 mg catechin equivalents (CE)/g DW of total a-
vonoids content (TFC) (BJ Xu & Chang, 2007). Lentils also con-
tain 1.5–2.6 mg/g of total phenolic acids (Xu and Chang, 2010).
Amarowicz et al. (2009, 2010) identied 24 phenolic compounds
including phenolic acids and avonoids in the extractable fraction
of red lentil and 20 in green lentil. They found that p-hydroxyben-
zoic acid, trans-p-coumaric acid, trans-ferulic acid and sinapic acid
were major phenolic acids in red lentil, whereas trans-p-coumaric
acid and trans-ferulic acid were mainly present in green lentil. The
content of individual avonoids in lentils ranged from 0.27 to 289
μg/g DW. Flavonols, avan-3-ols and condensed tannins (proan-
thocyanidins), such as kaempeferol glycoside, quercetin diglyco-
side, catechin, epicatechin, prodelphinidin dimer and digallate pro-
cyanidin, were identied as the predominant avonoids of lentils
in the study reported by Zou et al. (2011). Alshikh et al. (2015)
further fractionated the crude phenolic extract of lentils and found
that majority of the extractable phenolics were in esteried form
(2.32–21.54 mg GAE/g) rather than in free form (1.37–5.53 mg
GAE/g). Catechin, epicatechin and procyanidins B were predom-
inant avonoids in both free and esteried fractions of all tested
lentils. They also identied and quantied methyl vanillate and pro-
delphinidin dimer A in lentils for the rst time. Others have found
that monomeric avan-3-ols (catechin and epictechin), as well as
limited amount of avone (luteolin) were present in 11 selected len-
til cultivars (Xu and Chang, 2010). Our recent study revealed that
avonols such as kaempeferol glycoside, and avan-3-ols mainly
catechin and epicatechin glycosides were the predominant pheno-
lics in the aqueous methanolic extract of 20 lentil cultivars, and
it was these compounds that contributed most to the antioxidant
capacity of lentils (Zhang et al., 2015). The varied avonoid com-
positions in lentils among published data might be attributed to the
different genotype, growing environment, extraction condition and
chromatography system. Anthocyanins are pigmented avonoids
found in dark colored lentil varieties, and there is very limited in-
formation available in the literature. Early studies showed that lentil
seeds contained a compound that resembled a diglycosyl derivative
of delphinidin (D’Arcy and Jay, 1978). Takeoka et al. (2005) rst
isolated a major anthocyanin from the acidied methanolic extract
of Beluga black lentils, and identied as delphinidin 3-O-(2-O-β-D-
glucopyranosyl-α-L-arabinopyranoside).
The distribution of phenolic compounds differs greatly in the
cotyledon and the seed coat of lentils. Although the lentil seed coat
accounts for only 8 to 11% percent of the whole seed weight, it pro-
vides signicant contribution to the overall benets of lentils (Due-
nas et al., 2006). Mirali et al. (2014) reported that phenolic com-
pounds in lentil seed coat were more abundant and diverse than in
the cotyledon. The seed coat was found to contain a large amount
Journal of Food Bioactives | www.isnff-jfb.com 95
Zhang et al. Phytochemicals of lentil (Lens Culinaris)
Table 1. Phytochemical studies related to lenls
Phytochemicals Samples Extract solvent Content Concentraon Processing eects References
Extractable
Phenolics
Red Chief lenl
from Spokane
Acidic 70% acetone TPC 7.53 mg GAE/g DW Xu and Chang, 2007;
Eleven lenls
from North
Dakota
70% acetone with
0.5% acec acid
Benzoic acid derivates
Cinnamic acid derivates
Total phenolic acid
Flavan-3-ol
Flavone
Total avonoids
169.7–248.1 μg/g
1315.6–2381.7 μg/g
1543.7–2551.4 μg/g
266.9–4946.7 μg/g
18.22–77.13 μg/g
3524.1–6870.8 μg/g
Xu and Chang, 2010;
Green and
Red lenl
from Poland
80% acetone Phenolic acids
Flavan-3-ol monomeric
Proanthoccyanidins
Flavonol
0.06–73.46 μg/g
6.65–289 μg/g
5.3–154.8 μg/g
0.27–287.84 μg/g
Amarouwica et al. 2010;
Amarouwica et al. 2009;
Lenl from
Spokane
(Morton culvar)
70% acetone with
0.5% acec acid
(Crude extract)
TPC 70.0 mg GAE/g
Extract
Zou et al., 2011;
Eluted with
80% MeOH
TPC 377.2 mg GAE/g
Extract
Lenls from
Saskatoon,
Canada
Supernatants were
extracted with
diethyl ether and
ethyl acetate (Free
phenolic fracon)
TPC
Hydroxybenzoic acids
and derivaves
Hydroxycinnamic
acids and derivaves
Flavonoids and
derivaves
1.37–5.94 mg GAE/g
defaed sample
0–0.81 μg/g
0.63–10.4 μg/g
150–270 μg/g
Alshikh, et al., 2015;
Aqueous phase
was hydrolyzed by
alkali (Esteried
phenolic fracon)
TPC
Hydroxybenzoic acids
and derivaves
Hydroxycinnamic
acids and derivaves
Flavonoids and
derivaves
2.32–15.4 μg/g
0–7.13 μg/g
2.86–15.8 μg/g
109–486 μg/g
Green and red
lenls from
Canada
70% MeOH with
0.1% HCl
TPC
Total avonol index (TFI)
Total Phenolic
index (TPI)
4.56–8.34 mg/g DW
351.82–528.42 μg/g
594.63–952.55 μg/g
Domesc cooking
decreased the avanols, and
increased the avonols
Zhang et al., 2015;
Zhang et al., 2014b;
Two lenl (Lens
culinaris) cv
Pardina and
Crimson
30%
dimethylformamide
TPC 11.8–12.0 mg GAE/g TPC decreased 80% by
decorcaon, 16–41% by
cooking, 22–42% by soaking
Han and Baik, 2008;
Lenl cv. CDC
Richlea
Acidic 70% acetone TPC around 7.8
mg GAE/g
All thermal processing
decreased total phenolics
by around 60%
Xu and Chang, 2009;
Journal of Food Bioactives | www.isnff-jfb.com
96
Phytochemicals of lentil (Lens Culinaris)Zhang et al.
Phytochemicals Samples Extract solvent Content Concentraon Processing eects References
Lenl cv. Pardina 80% methanol
with HCl
Hydroxybenzoic and
hydroxycinnamic
compounds
Flavonols and avones
Slbenes
Proanthocyanidins
0.73–10.02 μg/g
0.33–6.20 μg/g
0.93 μg/g
0.29–31.50 μg/g
All enzymac treatments
decreased hydroxycinnamic
and proanthocyanidins content,
treatment of tannase increased
quercen 3-O-runoside
and luteolin content
Dueñas et al., 2007;
Lenls (Lens
culinaris L., var.
Castellana)
80% methanol
with HCl
Phenolic acids
Flavan-3-ol
13.3–342 μg/g
0.1–0.5 μg/g
Soaking decreased all of the
lenl phenolics, whereas
germinaon resulted in an
overall increase of phenolics
López-Amorós
et al., 2006;
Lenl var. Tina
from Poland
70% acetonee
with 1% HCl
TPC
Phenolic acids
Flavonoids
18.98 mg/g FW
0.78–44.46 μg/g FW
0.25–393.79
μg/g FW
p-hydroxybenzoic, benzoic
and caeic acids was
signicant increased on days
3 and 4 aer germinaon
Świeca et al., 2012;
Insoluble-
Bound
Phenolics
Lenls from
Saskatoon,
Canada
Residue was
hydrolysed with
4 M NaOH
TPC
Hydroxybenzoic acids
and derivaves
Hydroxycinnamic
acids and derivaves
Flavonoids and
derivaves
1.21–9.68 mg GAE/g
defaed sample
0.20–1.87 μg/g
0.07–4.74 μg/g
73.1–458 μg/g
Alshikh, et al,, 2015;
Lenls from
Canada
Residue was
hydrolyzed with
2 M NaOH
TPC
Phenolic acids
Total phenolic
index (TPI-B)
0.11–0.29 mg GAE/g
1.09–71.04 μg/g
115.72–217.25 μg/g
Domesc cooking negavely
aected the release of
bound phenolics in lenl
Zhang et al., 2014b;
CDC Richlea
lenls
Residue was
hydrolysed with
4 M NaOH
TPC 4.78 mg GAE/g Geminaon signicant increased
the phenolic content
Yeo and Shahidi, 2015
Carotenoids
and
Tocopherols
Green and
white lenls
from France
Hexane:acetonee
(1:1, v/v)
Carotenes
Neoxanthin
Lutein
0.020–0.028
mg/100 g edible
poron
0.042 mg/100 g
edible poron
1.061–1.196
mg/100 g edible
poron
Biehler et al., 2012;
Green and red
lenls from
Canada
Hexane/isopropanol
(3:2, v/v)
all-trans-lutein
all-trans-Zeaxanthin
Total carotenoids idex
α-Tocopherol
γ-Tocopherol
δ-Tocopherol
Total tocopherol
3.07–14.31 μg/g
0.25–2.09 μg/g
4.64–19.63 μg/g
0.16–0.90 μg/g
36.32–63.54 μg/g
0.33–1.25 μg/g
37.38–64.38 μg/g
Domesc cooking increased
release of tocopherols
and carotenoids
Zhang et al., 2014;
Zhang et al., 2014b;
Table 1. Phytochemical studies related to lenls - (connued)
Journal of Food Bioactives | www.isnff-jfb.com 97
Zhang et al. Phytochemicals of lentil (Lens Culinaris)
Phytochemicals Samples Extract solvent Content Concentraon Processing eects References
Lenl from
Ireland local
store
Hexane/diethyl-
ether (1:1, v/v)
α-Tocopherol
β+γ-Tocopherol
1.6 mg/100 g
4.5 mg/100 g
Ryan et al., 2007;
Lenls cv
Agueda, cv
Almar, cv Paula,
and cv Alcor.
From Spain
Pure methanol α-Tocopherol
β-Tocopherol
γ-Tocopherol
δ-Tocopherol
3.84–8,69 μg/g
1.94–3.81 μg/g
91.11–104.68 μg/g
2.01–2.74 μg/g
Germinaon and cooking
decreased β-, γ- and
δ-Tocopherol, increased
α-Tocopherol
Fernandez-Orozco
et al., 2003;
Saponins Lenls (Lens
esculenta var.
Magda 20 and
Lyda) from Spain
70% ethanol with
0.01% EDTA and
1-butanol
soyasaponinVI 703–1139 mg/
kg DW
Soaking did not modify the
saponin content, cooking
degraded soyasaponin
VI into soyasaponin I
Ruiz, Price et al., 1996;
Lenls from
Spain
Methnol Total saponin content 654–1269 mg/
kg DW
Ruiz et al., 1997;
Lenls from
Italian
70% ethanol soyasaponin I
soyasaponin βg (VΙ)
28–407 mg/kg DW
110–1242 mg/
kg DW
Sagrani et al., 2009;
Lenls (Lens
esculenta var.
Magda 20)
from Spain
Methnol Soyasapogenol B 0.34 mg/g DW Germinaon signifaicant
increased saponin
content at day 6
Ayet et al., 1997;
Phyc acid Lenls (Lens
esculenta var.
Magda 20)
from Spain
0.5 M HCl IP4
IP5
IP6
Total Inositol
phosphates content
0.09 mg/g
0.72 mg/g
4.91 mg/g
5.67 mg/g
Germinaon signifaicant
decreased phyc acid
Ayet et al., 1997;
Lenls (Lens
esculenta var.
Angela)
Acec acid/
sodium hydroxide
0.1 N, pH 5.5
IP3
IP4
IP5
IP6
0.27 g/kg
0.48 g/kg
0.75 g/kg
2.69 g/kg
commercial phytase
decreased IP4, IP5 and IP6,
whereas did not aect IP3
Frias et al., 2003;
Phytosterols Lenl from
Ireland local
store
Hexane/diethyl-
ether (1:1, v/v)
β-Sitosterol
Campesterol
Sgmasterol
123.4 mg/100 g
15.0 mg/100 g
20.0 mg/100 g
Ryan et al., 2007;
Lenls from
Greece (cooked)
Hexane extract aer
hot saponicaon
β-Sitosterol
Campesterol
Sgmasterol
15.4–24.2 mg/100 g
2.60–2.63 mg/100 g
2.18–2.58 mg/100 g
Kalogeropoulos
et al., 2010;
Table 1. Phytochemical studies related to lenls - (connued)
Journal of Food Bioactives | www.isnff-jfb.com
98
Phytochemicals of lentil (Lens Culinaris)Zhang et al.
of monomeric avan-3-ols, proanthocyanidin oligomers and poly-
mers, as well as small amounts of glycosides of avonols such as
quercetin, myricetin, luteolin, and apigenin. Phenolic acids, on the
other hand, such as hydroxybenzoic and hydroxycinnamic acids, in
both free and bound forms, were mainly present in the cotyledon of
lentils (Dueñas et al., 2002). Interestingly, a stilbene trans-resver-
atrol-5-glucoside was identied for the rst time in the seed coat
of lentils (Dueñas et al., 2002). The same research group further
reported the structural compositions of proanthocyanidins, the major
group of polyphenols present in the seed coat of lentils (Dueñas et
al., 2003). The proanthocyanidins in the seed coat of lentil mainly
included monomeric, oligomeric, and polymeric avan-3-ols. The
major monomeric avan-3-ol was (+)-catechin-3-glucose, with less-
er amounts of (+)-catechin and (−)-epicatechin aglycones. Various
dimer, trimer, and tetramers constituted of catechin, gallocatechin,
and catechin gallate units were identied in the oligomeric frac-
tion, and several procyanidins and prodelphinidins from pentamers
to nonamers in the polymeric fraction. Approximately 65−75% of
proanthocyanins in the seed coat of lentils are polymers with 7–9
mDP (mean degree of polymerization), and 20−30% are oligomers
with an mDP of 4−5. Proanthocyanins are strong antioxidants and
have been reported to have many health benecial effects, thus it is
highly recommended that lentils are consumed in-whole.
2.2. Insoluble/Bound phenolics
Apart from most studied extractable phenolics, there still exist easily
neglected insoluble or bound phenolics that are commonly associ-
ated with cell wall materials. The lack of assessing bound phenolics
leads to underestimation of the total phenolic content and the overall
actual health benets of lentils or other pulses. In general, organic
solvents such as ethanol, methanol and acetonee are employed to di-
rectly extract the soluble phenolics (extractable phenolics) in plants,
whereas insoluble-bound phenolics can only be released upon alkali,
acid, or enzymatic treatment of samples before extraction (Andreas-
en et al., 2001; Bartolome and Gómez-Cordovés, 1999; Zupfer et al.,
1998). The insoluble-bound phenolics are considered to contribute
additional health benets because they may avoid degradation under
upper gastrointestinal digestion conditions, and are absorbed into
teh circulation system or epithelial cells after being released by in-
testinal microora fermentation (Andreasen et al., 2001). However,
unlike other plants such as cereals, fruits and vegetables, insoluble-
bound phenolics of pulses, particularly lentils, and their potential
contribution to health benets have not been well studied. Han and
Baik (2008) found that bound phytochemicals contributed more
to total antioxidant activity in lentils than free (extractable) phyto-
chemicals. The TPC of insoluble-bound phenolics in lentils ranged
from 0.18 to 17.5 mg GAE/g, whereas TFC ranged from 0.03 to
4.13 mg CE/g (Alshikh et al., 2015; Zhang et al., 2014b). Alshikh et
al. (2015) identied 15 compounds including hydroxybenzoic acids,
hydroxycinnamic acids, avonoids and their derivatives in the insol-
uble-bound fraction of lentils. Catechin, catechin-3-glucoside and
procyanidin dimer Bweree the predominant phenolic compounds
identied in the insoluble-bound fractions of 6 tested lentil cultivars.
In our previous study, ve phenolic compounds including gallic
acid, protocatechuic acid, catechin, epicatechin and 3-hydroxycin-
namic acid were identied in the insoluble-bound fractions of lentils
(Zhang et al., 2014b).
2.3. Carotenoids and tocopherols
Carotenoids and tocopherols are well-known lipophilic antioxi-
dants that are synthesized in whole or in part from the plastid iso-
prenoids (DellaPenna and Pogson, 2006). Carotenoids comprise a
large isoprenoid family and most are C40 tetra-terpenoids derived
from phytoene. It provides plants with distinctive red, orange, and
yellow colours. Tocopherols are a group of nutrients that consti-
tutes vitamin E that are essential to health of all mammals. Lentils
are a good source of both carotenoids and tocopherols. Biehler et
al. (2012) reported presence of lutein, carotenes and neoxanthin
in lentils, among which lutein (1.061–1.196 mg/100 g edible por-
tion) was the major carotenoid. Our recent study examined the
carotenoid and tocopherol compositions in 20 lentil cultivars (10
green and 10 red) (Zhang et al., 2014a). All-trans-lutein accounted
for 64–78% of the total carotenoid content (TCC) in lentils, fol-
lowed by all-trans-zeaxanthin, which constitutes 5–13% of TCC.
The total lutein and zeaxanthin contents (total of all-trans and cis-
isomers) in lentils ranged from 4.32–17.29 µg/g DW to 0.32–2.73
µg/g DW, respectively. Total tocopherols of lentils were from 37–
64 µg/g DW, predominantly γ-tocopherol (96–98% of the tocoph-
erol content), followed by δ- and α-tocopherols. Similar results
were repored by Ryan et al. (2007) who did not separate all tocoph-
erol isomers. All α-, β-, γ- and δ-tocopherol isomers were reported
in lentils in another study (Fernandez-Orozco et al., 2003). When
consumed daily, these carotenoids and tocopherols of lentils can
provide substantial nutritional and health benets.
2.4. Saponins
Saponins are a diverse group of compounds characterized by a car-
bohydrate moiety attached to a steroid or triterpenoid aglycone in
their structures. These phytochemicals have long been considered
undesirable due to their toxicity and haemolytic activity. Saponins
in pulses such as lentils however are attracting considerable inter-
est in recent years due to their ability to lower plasma cholesterol
levels in human and suppress cancer growth. Pulses including
lentils are considered among the best sources of saponins. Total
saponin content of lentils has been reported to be in the range of
654–1269 mg/kg DW, and the main saponins were soyasaponin I
and VI in Spanish lentils (Ruiz et al., 1996; Ruiz et al., 1997). Sa-
gratini et al. (2009) tested 32 Italian lentils, and found soyasaponin
I and soyasaponin βg (also known as VΙ) to be 28–407 mg/kg and
110–1242 mg/kg.
2.5. Phyc acid
Phytic acid (or inositol hexaphosphate, IP6) is a saturated cyclic
acid, and is considered as the major source of phosphorus in many
plant tissues or organs, especially in seeds. The catabolites of phyt-
ic acid are called lower inositol polyphosphates including inositol
tri- (IP3) , tetra- (IP4) and penta-phosphate (IP5). Phytic acid has
been proposed to serve a vital role in protecting the seeds against
the deleterious effects of oxygen and iron (Graf and Eaton, 1990).
Lentils have been reported to contain 86% of IP6 (4.91 mg/g), 13%
of IP5 (0.72 mg/g) and trace amount of IP4 (0.09 mg/g) (Ayet et
al., 1997).
2.6. Phytosterols
Phytosterols, primarily β-sitosterol, campesterol, and stigmasterol,
are integral natural components of plant cell membranes. They
are proposed to have a wide range of biological effects includ-
ing anti-inammatory, anti-oxidative, anti-carcinogenic activities
Journal of Food Bioactives | www.isnff-jfb.com 99
Zhang et al. Phytochemicals of lentil (Lens Culinaris)
and cholesterol-lowering ability (Berger et al., 2004). Studies have
shown that phytosterols can inhibit the intestinal absorption of
cholesterol, thus lowering total plasma cholesterol and low-density
lipoprotein (LDL) levels (de Jong et al., 2003). Pulses including
lentils are one of the important dietary sources of phytosterols,
along with vegetable oils, nuts and cereal grains. β-Sitosterol was
found to be the most prevalent phytosterol in lentils, of which the
concentration was 123.4 mg/100 g, followed by 20.0 mg/100 g of
stigmasterol and 15.0 mg/100 g of campesterol (Ryan et al., 2007).
In another study, Kalogeropoulos et al. found that the predominant
β-sitosterol ranged from 15.4 to 24.2 mg/100 g in cooked lentils,
whereas the contents of stigmasterol and campesterol ranged from
2.60–2.63 to 2.18–2.58 mg/100 g, respectively (Kalogeropoulos
et al., 2010).
3. Processing eects on phytochemicals in lenls
Lentils are usually processed before consumption. Processing not
only improves the avour and palatability of lentils, but also sig-
nicantly affects their phytochemical content and proles, as well
as the antioxidant capacities. The stability of phytochemicals dur-
ing processing has been a major concern. Han et al. reported that
the total antioxidant activity and total phenolic content (TPC) of
lentils was reduced by ca. 80, 16–41 and 22–42% by decortication,
cooking and soaking, respectively (Han and Baik, 2008). Interest-
ingly, they observed a loss of 94.8% in the total antioxidant activ-
ity of bound phenolics of lentils by decortication, indicating that
most of the bound phytochemicals are distributed in the seed coat,
whereas the total antioxidant activity of free phenolics increased
by 10–36% in lentils after cooking probably due to the release of
the conjugated phenolics during cooking. Xu et al. (2009) com-
pared the inuences of four thermal processing methods (conven-
tional boiling, conventional steaming, pressure boiling, and pres-
sure steaming) on phytochemical proles, antioxidant capacities,
and antiproliferation properties of commonly consumed cool-sea-
son food legumes including lentils. All thermal processing resulted
in signicant (P < 0.05) reductions in total phenolic, procyanidin,
total saponin, phytic acid, chemical antioxidant capacities (ferric
reducing antioxidant power, FRAP; and peroxyl radical scaveng-
ing capacity, ORAC), and cellular antioxidant activity (CAA), as
well as anti-proliferation capacities of lentils, as compared to raw
lentils. Conventional boiling, pressure boiling and pressure steam-
ing caused signicant (p<0.05) decreases in gallic, chlorogenic,
sinapic, p-coumaric acid, subtotal, and total phenolic acids, and
signicant increases in 2,3,4-trihydroxybenzoic acid, whereas con-
ventional steaming did not cause signicant changes in the chlo-
rogenic and sinapic acid, subtotal cinnamic acid and total phenolic
acid. Different thermal processing methods present signicant dif-
ferences. Their results indicated that steaming was a better cooking
method than boiling in retaining antioxidants and phenolic com-
ponents, whereas boiling was effective in reducing saponin and
phytic acid contents (Xu and Chang, 2009). Our recent study found
that cooking favours the release of carotenoids, tocopherols and
avonols (kaempferol glycosides) but leads to losses of avanols
(monomeric and condensed tannin) (Zhang et al., 2014b). Howev-
er, a signicantly reduction in tocopherols including α-, β-, γ- and
δ-tocopherols resulted from cooking was observed by Fernandez-
Orozco et al. (2003). Elhardallou and Walker (1994) determined a
loss of 60.5% in phytic acid in lentils during autoclaved cooking.
Ruiz et al. (1996) observed that soaking did not modify the saponin
content or composition of lentils regardless of the pH of the soak-
ing solution. The native soyasaponin VI in lentils, however, was
found to be partially degraded into soyasaponin I during cooking,
and an overall loss of 15–31% in total saponin content was found
for lentils.
Exogenous enzyme treatment and germination could also have
signicant effects on the phytochemicals in lentils. Dueñas et al.
investigated the effect of the enzymes tannase, α-galactosidase,
phytase and viscozyme on the phenolic composition of lentils, and
found that all exogenous enzyme treatment changed phenolic com-
position of lentil ours, particularly those of the hydroxycinnamic
compounds and proanthocyanidins that are signicantly decreased
after the enzymatic treatments, whereas quercetin 3-O-rutinoside
and luteolin increased and reached the highest concentration by
treatment of tannase. Trans-resveratrol was only observed in the
lentils treated by the tannase and phytase, and gallic acid was
formed by the action of phytase, α-galactosidase and tannase. The
treatments of viscozyme, α-galactosidase or tannase increased the
antioxidant capacity as compared to raw lentils, and the querce-
tin 3-O-rutinoside was evident to be the main compound affecting
antioxidant activity (Dueñas et al., 2007). After addition of com-
mercial phytase to lentil our, a reduction of 85–91, 57–69 and
6–27% in IP6, IP5 and IP4, respectively, was observed, whilst did
not signicantly change the content of IP3 (Frias et al., 2003). In
general, the phenolic content in lentils tend to steadily decline dur-
ing germination due to leaching into the soaking water, binding
with other organic substances such as carbohydrates or proteins,
and the activation of endogenous enzymes such as hydroxylases
and polyphenoloxydases. López-Amorós et al. (2006) reported a
general decrease in all of the lentil phenolics including hydroxy-
benzoic acids, hydroxycinnamic acids, (+)-catechin and procya-
nidin oligomers after soaking when compared with raw seeds,
thereafter germination resulted in an overall increase of phenolics
in lentils, with the exception of protocatechuic acid where no in-
crease took place. It is worth noting that some of hydroxycinnamic
compounds such as transp-coumaric acid and trans-ferulic acid ,
which had decreased or disappeared after soaking, were detected
and increased from the beginning of the germination period. The
hydroxycinnamic compounds are the constituents of plant cell
walls, in various bonds and esteried forms, linked to arabinoxy-
lans and lignin. The changes observed in these hydroxycinnamic
compounds during germination therefore could be well explained
by the action of the endogenous esterases. Yeo et al. (2015) even
proposed a new indicator, the ratio of insoluble bound phenolics
(IBPs) to soluble phenolics (SPs), to monitor changes in the an-
tioxidant activity of lentils during germination. They observed an
increase of TPC in both SPs (from 3.35 to 4.25 mg GAE/g of defat-
ted weight (DW)) and IBPs (from 4.78 to 6.45 mg GAE/g of DW)
of lentils during germination. Total avonoids contents (TFC) of
SPs decreased from 2.49 to 1.96 mg CE/g of DW during the 4 days
of germination probably due to the degradation of avonoids by
oxidants such as ROS produced in the mitochondria, whereas that
of IBPs increased from 2.98 to 3.85 CE mg/g (Yeo and Shahidi,
2015). Cevallos-Casals and Cisneros-Zevallos (2010) found that
TPC of SPs from green lentils was increased signicantly during 7
days germination. The condition of germination and illumination
was found to have varied effects on the phenolic components of
lentils and their biological activity. Phenolics were stimulated by
cultivation under continuous light, and the content of p-hydroxy-
benzoic, benzoic and caffeic acids was signicant increased on
days 3 and 4 after germination (Świeca et al., 2012). Additionally,
the contents of β-, γ- and δ-tocopherols were reported to decrease
by 33.6–42.5, 29.3–55.4 and 23.7–47.1%, respectively, in germi-
nated lentil seeds of all cultivars, but the contents of α-tocopherol
increased by 1.6–48.9% in germinated seeds when compared to
that of the raw lentils of all cultivars being investigated (Fernan-
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100
Phytochemicals of lentil (Lens Culinaris)Zhang et al.
dez-Orozco et al., 2003). Ayet et al. (1997) observed that germinat-
ed lentil seeds at day 6 contained highest levels of soyasapogenol
B, whereas total phytic acid amounts were greatly reduced after 6
days germination.
4. Anoxidant eects
Given the fact that in situ analysis of the antioxidant activity in vivo
is currently impossible, the antioxidant properties of phytochemi-
cals in plant was mostly evaluated by chemical-based assays, such
as Trolox equivalent antioxidant capacity (TEAC), 2,2-diphenyl-
1-picrylhydrazyl radical scavenging (DPPH), FRAP, ORAC, to-
tal radical-trapping antioxidant parameter (TRAP), inhibition of
photochemiluminescence (PCL), inhibition of oxidation of human
low-density lipoprotein cholesterol (LDL) and DNA, and iron(II)
chelation activity. These antioxidant assay methods are mainly
based on two mechanisms, the hydrogen atom transfer (HAT) and
the single electron transfer (SET). In the methods of ORAC and
PCL, lentil phytochemicals may act as free radical scavengers by
donating a hydrogen atom, while assays that determine the ability
to inhibit LDL and DNA oxidation by lentil phytochemicals, the
antioxidant properties may be based on both hydrogen donation
and metal chelation. Commonly used methods such as TEAC and
FRAP are considered to detect the ability of lentil phytochemicals
to transfer single electron (SET) to reduce any compound includ-
ing metals, carbonyls and free radicals, whereas DPPH method is
considered to follow both HAT and SET system. Several second-
ary constituents in lentil, mainly phenolics, appeared to serve as
powerful antioxidants by preventing against oxidative and free
radical mediated reactions. Most of researches on the phenolic
proles of lentils hitherto overviewed use these chemical-based
methods to determine the antioxidant activities. These methods
may give different equivalent numbers. The total antioxidant activ-
ity determined by the ABTS (2,2′-azinobis-3-ethyl-benzthiazoline-
6-sulfonic acid) assay was highest in lentils at around 14 μmol
Trolox equivalent antioxidant capacity (TEAC)/g among 5 tested
legumes, and insoluble-bound phenolics contributed 82–85% of
total antioxidant activity in lentils (Han and Baik, 2008). These
ndings were also conrmed by Pellegrini et al. who observed
that lentils had the highest total antioxidant capacity measured by
FRAP and TRAP among tested pulses, but came second to broad
beans by TEAC. Similarly, Xu et al. reported that lentils had the
highest DPPH and ORAC activity in comparison with green pea,
yellow pea and chickpea (Xu and Chang, 2008). Alshikh et al.
(2015) found that all fractions including free, esteried and insolu-
ble-bound from selected lentils showed varied reducing power and
scavenging activity against DPPH, hydroxyl radicals and ABTS
radical cation. Their potential bioactivity was further conrmed
through inhibition of cupric ion induced human LDL peroxida-
tion and peroxyl radical induced DNA strand breakage. Accord-
ing to our recent studies, the DPPH, FRAP and ORAC values of
phenolics in lentils were in the range of 23.83–35.03 µmol TE/g
DW, 18.75–34.52 AAE/g DW and 105.06–168.03 µmol TE/g DW,
respectively, whilst the antioxidant activities of lentil hydrophobic
fraction containing carotenoids and tocopherols were determined
as 3.61–4.48 µmol TE/g DW and 2.73–6.23 µmol TE/g DW in the
DPPH and PCL assay, respectively (Zhang et al., 2014a; Zhang et
al., 2015).
CAA has recently been developed for the evaluation of antioxi-
dant activity to overcome the lack of biological and physiological
relevance of the chemical-based assays,. This method measures
the ability of antioxidants to prevent the formation of uorescent
dichlorouorescein (DCF) by 2, 20-azobis (2-amidinopropane) di-
hydrochloride (ABAP)-generated peroxyl radicals in live cell lines.
CAA is considered more biologically relevant than the chemistry-
based assays due to accounting of the absorption, metabolism and
location of antioxidants inside a living cell. Lentil was reported to
exhibit the greatest CAA with the lowest IC50 value (0.67 mg/mL),
followed by yellow pea and green pea, whereas raw chickpea did
not exhibit dose-dependent CAA. Pressurized steaming reduced
CAA of lentil with increased IC50 value of 1.88 mg/mL (Xu and
Chang, 2009). The same authors determined CAA of 11 selected
lentil cultivars with the IC50 values ranging from 0.30 to 1.41 mg/
mL, and revealed that the CAA results signicantly correlated with
chemical antioxidant assay ORAC (Xu and Chang, 2010).
5. An-inammatory eects
Inammation is known as a basic defense mechanism of respons-
es to infection, burn, toxic chemicals, allergens or other noxious
stimuli. However, excessive or persistent inammation may lead
to tissue destruction and many chronic diseases. There are two
scenarios when the inammatory response itself damages host tis-
sue and causes organ dysfunction. One being an extremely acute
or subacute inammatory response that occurs when there is se-
vere attacks from pathogens (sepsis) or debris from damaged host
cells, and the other is pathologic inammation or low grade in-
ammation, which when regulation of its pathways is disrupted,
triggers chronic diseases such as atherosclerosis, type 2 diabetes
and Alzheimer’s disease (Tabas and Glass, 2013). As inammatory
reactions often include the formation of tissue-damaging oxida-
tion products, i.e. increased oxidative stress, compounds with high
antioxidant activity may inhibit inammation. Interestingly, lentils
have long been used by ancient treatment remedies to treat some
inammatory symptoms, such as skin infections by its water paste
and the treatment of burns, after being roasted, milled and applied
directly to affected areas (Sezik et al., 2001; Teklehaymanot et al.,
2007). Additionally, regular consumption of pulse foods, particu-
larly lentils, have been evidenced by many researches to reduce the
incidence of developing chronic inammatory disease including
type 2 diabetes, cardiovascular diseases (CVD) and cancers (Ade-
bamowo et al., 2005; Anderson et al., 2007; Rizkalla et al., 2003).
Phenolic-rich lentils have the potential to reduce blood pressure
due to its angiotensin I-converting enzyme (ACE) inhibitor ac-
tivity (Boye et al., 2010; Hanson et al., 2014). The recent study
observed that bioactive compounds such as legumin, vicilin and
convicilin in lentil present higher ACE-inhibitory and cardiopro-
tective activity (Garcia-Mora et al., 2014). In a hypertensive ani-
mal model, lentils administration can reduced the total cholesterol
(TC), triglycerides (TG), low density lipoprotein (LDL) and path-
ological manifestations of cardio-morphometric analysis (Lukito
et al., 2001). The specic bioactive components that exert these
protective benets on inammatory-related diseases still need to
be further identied and the mechanisms explored. Cyclooxyge-
nases (COX) and lipoxygenase (LOX) are two major metabolic
routes controlling eicosanoid biosynthesis. COX-1 and COX-2
regulate inammatory responses differentially, thus different types
of inhibitors are required for the anti-inammatory effects. COX-
2 inhibitors increase inammation risk whereas COX-1 inhibitors
reduce it. COX-2 is a key enzyme catalyzing the production of
prostaglandins (PG) in response to inammatory stimuli (Surh,
2002). The inhibition of prostaglandin E2 (PGE2) and nitric ox-
ide (NO) production has been considered a potential therapy for
different inammatory disorders. While the nuclear transcription
Journal of Food Bioactives | www.isnff-jfb.com 101
Zhang et al. Phytochemicals of lentil (Lens Culinaris)
factor (NF-κB) is the target of the intracellular signaling pathways
responsible for induction of COX-2 expression, it can be a posi-
tive regulator of COX-2 in diverse cell types (Surh et al., 2001).
Many studies reported that plant-derived phenolics and avonoids
exhibit excellent anti-inammatory activity by regulating the lev-
els of various inammatory cytokines or mediators including IL-1,
IL-6, IL-10, TNF-α, NF-κB, NO, iNOS, LOX, COX-1 and COX-2
(Wu et al., 2011). Boudjou et al. (2013) found that aqueous etha-
nol (80%) extract of lentil hulls exhibited high anti-inammatory
activities preferentially inhibiting 15-LOX (IC50, 55 μg/ml), with
moderate COX-1 (IC50, 66 μg/ml) and weak COX-2 (IC50, 119 μg/
ml) inhibitory effects on the COX pathway. Current research on the
anti-inammatory activity of lentil is limited to the in vitro studies
of phenolics fraction. We have recently reported that phenolics of
lentils showed dose-dependent anti-inammatory activity against
pro-inammatory cytokines COX-2, IL-1β and IL-6 in TNF-α-
induced inammation in Caco-2 cells. The antioxidant and anti-in-
ammatory activities were positively correlated with the total and
individual phenolic contents (Zhang et al. 2017). Concisely, these
studies suggest that the dietary consumption of polyphenolic-rich
lentils should be on a regular basis, having the potential to reduce
the risk of inammatory-related chronic diseases. More in vitro
and in vivo studies are needed to investigate the anti-inammatory
mechanisms of different phytochemicals in lentils.
6. Interacon with microbiome
The human intestinal tract is home to more than 100 trillion mi-
croorganisms. Gut microbes are believed to be involved in major
physiological activities, such as protecting gut epithelial cells from
pathogens invasion, stimulating the immune system, increasing
nutrient availability, stimulating bowel motility. After consump-
tion, foods containing phenolics may undergo a serial of enzyme
reactions, following alteration of physiochemical properties in the
digestive tract, including the mouth, stomach, small intestinal and
large intestine (colon). Those free Phenolic compounds are re-
leased from the food matrix in the stomach and small intestinal
(gastrointestinal tract) by enzymes and acidic or base conditions,
whereas majority of insoluble-bound phenolics survive in gastro-
intestinal tract digestion and transfer into the colon (large intes-
tine), and release single phenolics or metabolits by the activity of
digestive enzymes or colon microbiota. It was reported that only
5–10% of free phenolics can be absorbed in the small intestine,
while the remaining 90%–95% degrade and move directly to the
colon (Scalbert, A. & Williamson, G. 2000). Therefore, the interac-
tion between the insoluble-bound phenolics and microbiome might
play a critical role in the potential health benets of lentils. The
metabolism and absorption mechanism of insoluble-bound pheno-
lics of lentils in colon after microbiota fermentation has not yet
been well studied, which is worth investigating in future research.
7. Summary
The above review on the phytochemical composition, as well as
their antioxidant and anti-inammatory activity, indeed showed
that lentils contain a plethora of health promoting bioactives in ad-
dition to the macronutrients such as starch and protein. Many fac-
tors can affect the health benets of lentils, as the content and com-
position of phenolics, carotenoids, tocopherols and other nutrients
hitherto mentioned can vary signicantly in different cultivars, and
by different processing methods. Lentils have been traditionally
consumed as whole seeds, however, processing of lentil into dif-
ferent fractions, i.e. our, protein and starch, has been in steady
sharp growth in recent years due to increased consumer needs
in alternative plant protein (other than soy protein) and specialty
foods such as gluten-free foods. Lentil processing generates signif-
icant amount of seed coats which are currently of no or low value,
yet studies have shown that these are the major source of dietary
ber and antioxidant and anti-inammatory phenolics, in both free
and insoluble-bound forms. The high content of bound phenolics,
and the in vitro antioxidant and anti-inammatory effects of lentil
hulls warrant further studies in vivo. In addition, potential syner-
gistic effects may exist among different classes of phytochemicals.
Researches on the potential health benets of lentil bioactives have
not paid much attention to the bioaccessibility, bioavailability in
vivo. In order to be absorbed and to reach the target cells or tis-
sues at a certain level for these compounds, they have to survive
the gastrointestinal tract, and be uptaken and transported. This re-
quires a multidisciplinary in approach in future studies.
Acknowledgments
We thank Pulse Canada for providing the lentil samples. This pro-
ject is supported by the A-Base Project (#J-001322.001.04) of Ag-
riculture & Agri-Food Canada.
References
Adebamowo, C.A., Cho, E., Sampson, L., Katan, M.B., Spiegelman, D., Wil-
le, W.C., and Holmes, M.D. (2005). Dietary avonols and avonol-
rich foods intake and the risk of breast cancer. Int. J. Cancer 114(4):
628–633.
Aguilera, Y., Dueñas, M., Estrella, I., Hernández, T., Benitez, V., Esteban,
R.M., and Marn-Cabrejas, M.A. (2010). Evaluaon of phenolic pro-
le and anoxidant properes of Pardina lenl as aected by indus-
trial dehydraon. J. Agric. Food Chem. 58(18): 10101–10108.
Alshikh, N., de Camargo, A.C., and Shahidi, F. (2015). Phenolics of selected
lenl culvars: Anoxidant acvies and inhibion of low-density li-
poprotein and DNA damage. J. Funct. Foods 18: 1022–1038.
Amarowicz, R., Estrella, I., Hernández, T., Dueñas, M., Troszyńska, A.,
Kosińska, A., and Pegg, R.B. (2009). Anoxidant acvity of a red lenl
extract and its fracons. Int. J. Mol. Sci. 10(12): 5513–5527.
Amarowicz, R., Estrella, I., Hernández, T., Robredo, S., Troszyńska, A.,
Kosińska, A., and Pegg, R.B. (2010). Free radical-scavenging capacity,
anoxidant acvity, and phenolic composion of green lenl (Lens
culinaris). Food Chem. 121(3): 705–711.
Amarowicz, R., and Pegg, R.B. (2008). Legumes as a source of natural an-
oxidants. Eur. J. Lipid Sci. Technol. 110(10): 865–878.
Amarowicz, R., Troszynska, A., Barylko-Pikienla, N., and Shahidi, F. (2004).
Polyphenolics extracts from legume seeds: correlaons between to-
tal anoxidant acvity, total phenolics content, tannins content and
astringency. J. Food Lipids 11(4): 278–286.
Anderson, J.W., and Major, W.A. (2007). Pulses and lipaemia, short- and
long-term eect: Potenal in the prevenon of cardiovascular dis-
ease. Br. J. Nutr. S3: 263–271.
Andreasen, M.F., Kroon, P.A., Williamson, G., and Garcia-Conesa, M.-T.
(2001). Esterase acvity able to hydrolyze dietary anoxidant hydrox-
ycinnamates is distributed along the intesne of mammals. J. Agric.
Food Chem. 49(11): 5679–5684.
Andreasen, M.F., Landbo, A.-K., Christensen, L.P., Hansen, Å., and Meyer,
A.S. (2001). Anoxidant eects of phenolic rye (Secale cereale L.)
extracts, monomeric hydroxycinnamates, and ferulic acid dehydrodi-
mers on human low-density lipoproteins. J. Agric. Food Chem. 49(8):
4090–4096.
Ayet, G., Burbano, C., Cuadrado, C., Pedrosa, M., Robredo, L., Muzquiz,
M., De la Cuadra, C., Castano, A., and Osagie, A. (1997). Eect of ger-
Journal of Food Bioactives | www.isnff-jfb.com
102
Phytochemicals of lentil (Lens Culinaris)Zhang et al.
minaon, under dierent environmental condions, on saponins,
phyc acid and tannins in lenls (Lens culinaris). J. Sci. Food Agric.
74(2): 273–279.
Bartolome, B., and Gómez-Cordovés, C. (1999). Barley spent grain: release
of hydroxycinnamic acids (ferulic and p-coumaric acids) by commer-
cial enzyme preparaons. J. Sci. Food Agric. 79(3): 435–439.
Berger, A., Jones, P.J., and Abumweis, S.S. (2004). Plant sterols: factors af-
fecng their ecacy and safety as funconal food ingredients. Lipids
Health Disease 3: 5.
Bhay, R. (1988). Composion and quality of lenl (Lens culinaris Medik):
a review. Can. Inst. Food Sci. Technol. J. 21(2): 144–160.
Biehler, E., Alkerwi, A., Homann, L., Krause, E., Guillaume, M., Lair, M.-
L., and Bohn, T. (2012). Contribuon of violaxanthin, neoxanthin,
phytoene and phytouene to total carotenoid intake: assessment in
Luxembourg. J. Food Comp. Anal. 25(1): 56–65.
Boudjou, S., Oomah, B.D., Zaidi, F., and Hosseinian, F. (2013). Phenolics
content and anoxidant and an-inammatory acvies of legume
fracons. Food Chem. 138(2–3): 1543–1550.
Boye, J.I., Rouk, S., Pesta, N., and Barbana, C. (2010). Angiotensin I-con-
verng enzyme inhibitory properes andSDS-PAGE of red lenl pro-
tein hydrolysates. LWT-Food Sci. Technool. 43: 987–991.
Cevallos-Casals, B.A., and Cisneros-Zevallos, L. (2010). Impact of germina-
on on phenolic content and anoxidant acvity of 13 edible seed
species. Food Chem. 119(4): 1485–1490.
D’Arcy, A., and Jay, M. (1978). Les avonoïdes des graines de Lens culinaris.
Phytochemistry 17(4): 826–827.
Dahl, W.J., Foster, L.M., and Tyler, R.T. (2012). Review of the health benets
of peas (Pisum savum L.). Br. J. Nut. 108(S1): S3–S10.
de Jong, A., Plat, J., and Mensink, R.P. (2003). Metabolic eects of plant
sterols and stanols (Review). J. Nutr. Biochem. 14(7): 362–369.
DellaPenna, D., and Pogson, B.J. (2006). Vitamin synthesis in plants: toco-
pherols and carotenoids. Annu. Rev. Plant Biol. 57: 711–738.
Dueñas, M., Hernández, T., and Estrella, I. (2002). Phenolic composion
of the cotyledon and the seed coat of lenls (Lens culinaris L.). Eur.
Food Res. Technol. 215(6): 478–483.
Dueñas, M., Hernández, T., and Estrella, I. (2007). Changes in the content
of bioacve polyphenolic compounds of lenls by the acon of ex-
ogenous enzymes. Eect on their anoxidant acvity. Food Chem.
101(1): 90–97.
Dueñas, M., Sun, B., Hernández, T., Estrella, I., and Spranger, M.I. (2003).
Proanthocyanidin composion in the seed coat of lenls (Lens culi-
naris L.). J. Agric. Food Chem. 51(27): 7999–8004.
Duenas, M., Hernandez, T., and Estrella, I. (2006). Assessment of in vitro
anoxidant capacity of the seed coat and the cotyledon of legumes
in relaon to their phenolic contents. Food Chem. 98(1): 95–103.
Elhardallou, S.B., and Walker, A.F. (1994). Phyc acid content of three
legumes in the raw, cooked and bre forms. Phytochem. Anal. 5(5):
243–246.
Fernandez-Orozco, R., Zieliński, H., and Piskuła, M.K. (2003). Contribuon
of low-molecular-weight anoxidants to the anoxidant capacity of
raw and processed lenl seeds. Food/Nahrung 47(5): 291–299.
Frias, J., Doblado, R., Antezana, J.R., and Vidal-Valverde, C. (2003). Inositol
phosphate degradaon by the acon of phytase enzyme in legume
seeds. Food Chem. 81(2): 233–239.
Garcia-Mora, P., Penas, E., Frias, J., and Marnez-Villaluenga, C. (2014).
Savinase, the most suitable enzyme for releasing pepdes from lenl
(Lens culinaris var. Castellana) protein concentrates with mulfunc-
onal properes. J. Agric. Food Chem. 62: 4166–4174.
Graf, E., and Eaton, J.W. (1990). Anoxidant funcons of phyc acid. Free
Rad. Biol. Med. 8(1): 61–69.
Gumienna, M., Lasik, M., and Czarnecki, Z. (2009). Inuence of plant ex-
tracts addion on the anoxidave properes of products obtained
from green lenl seeds during in vitro digeson process. Pol. J.Food
Nutr. Sci. 59(4): 295–298.
Han, H., and Baik, B.K. (2008). Anoxidant acvity and phenolic content of
lenls (Lens culinaris), chickpeas (Cicer arienum L.), peas (Pisum sa-
vum L.) and soybeans (Glycine max), and their quantave changes
during processing. Int. J. Food Sci. Technol. 43(11): 1971–1978.
Hanson, M.G., Zahradka, P., and Taylor, C.G. (2014). Lenl-based diets at-
tenuate hypertension and large-artery remodelling in spontaneously
hypertensive rats. Br. J. Nutr. 111: 690–698.
Kalogeropoulos, N., Chiou, A., Ioannou, M., Karathanos, V.T., Hassapidou,
M., and Andrikopoulos, N.K. (2010). Nutrional evaluaon and bio-
acve microconstuents (phytosterols, tocopherols, polyphenols,
triterpenic acids) in cooked dry legumes usually consumed in the
Mediterranean countries. Food Chem. 121(3): 682–690.
López-Amorós, M., Hernández, T., and Estrella, I. (2006). Eect of germina-
on on legume phenolic compounds and their anoxidant acvity. J.
Food Comp. Anal. 19(4): 277–283.
Lukito, W. (2001). Candidate foods in the Asia-Pacic region for cardio-
vascular protecon: Nuts, soy, lenls, and tempe. Asia Pacic J. Clin.
Nutr. 10: 128–133.
Marathe, S.A., Rajalakshmi, V., Jamdar, S.N., and Sharma, A. (2011).
Comparave study on anoxidant acvity of dierent variees of
commonly consumed legumes in India. Food Chem. Toxicol. 49(9):
2005–2012.
Mirali, M., Ambrose, S.J., Wood, S.A., Vandenberg, A., and Purves, R.W.
(2014). Development of a fast extracon method and opmizaon of
liquid chromatography–mass spectrometry for the analysis of phe-
nolic compounds in lenl seed coats. J. Chromatogr. B 969: 149–161.
Mudryj, A.N., Yu, N., Hartman, T.J., Mitchell, D.C., Lawrence, F.R., and
Aukema, H.M. (2012). Pulse consumpon in Canadian adults inu-
ences nutrient intakes. Br. J. Nutr. 108(S1): S27–S36.
Rizkalla, S.W., Bellisle, F., and Slama, G. (2003). Health benets of low gly-
caemic index foods, such as pulse in diabec paents and healthy
individuals. Br. J. Nutr. 88(S3): 255–262.
Rochfort, S., and Panozzo, J. (2007). Phytochemicals for health, the role of
pulses. J. Agric. Food Chem. 55(20): 7981–7994.
Ruiz, R.G., Price, K.R., Arthur, A.E., Rose, M.E., Rhodes, M.J., and Fenwick,
R.G. (1996). Eect of soaking and cooking on the saponin content
and composion of chickpeas (Cicer arienum) and lenls (Lens culi-
naris). J. Agric. Food Chem. 44(6): 1526–1530.
Ruiz, R.G., Price, K.R., Rose, M.E., and Fenwick, G.R. (1997). Eect of seed
size and testa colour on saponin content of Spanish lenl seed. Food
Chem. 58(3): 223–226.
Ryan, E., Galvin, K., O’Connor, T., Maguire, A., and O’Brien, N. (2007).
Phytosterol, squalene, tocopherol content and fay acid prole of
selected seeds, grains, and legumes. Plant Foods Hum. Nutr. 62(3):
85–91.
Sagrani, G., Zuo, Y., Caprioli, G., Cristalli, G., Giardinà, D., Maggi, F., Molin,
L., Ricciutelli, M., Traldi, P., and Viori, S. (2009). Quancaon of
Soyasaponins I and βg in Italian Lenl Seeds by Solid-Phase Extracon
(SPE) and High-Performance Liquid Chromatography− Mass Spec-
trometry (HPLC-MS). J. Agric. Food Chem., 57( 23): 11226–11233.
Scalbert, A., and Williamson, G. (2000). Dietary Intake and Bioavailability
of Polyphenols. J. Nutr. 130(8): 2073S–2085S.
Schneider, A.V. (2002). Overview of the market and consumpon of puises
in Europe. Br. J. Nutr. 88(S3): 243–250.
Sezik, E., Yeşilada, E., Honda, G., Takaishi, Y., Takeda, Y., and Tanaka, T.
(2001). Tradional medicine in Turkey X. Folk medicine in Central
Anatolia. J. Ethnopharmacol. 75(2–3): 95–115.
Surh, Y.-J. (2002). An-tumor promong potenal of selected spice ingre-
dients with anoxidave and an-inammatory acvies: a short
review. Food Chem. Toxicol. 40(8): 1091–1097.
Surh, Y.-J., Chun, K.-S., Cha, H.-H., Han, S.S., Keum, Y.-S., Park, K.-K., and Lee,
S.S. (2001). Molecular mechanisms underlying chemoprevenve ac-
vies of an-inammatory phytochemicals: down-regulaon of
COX-2 and iNOS through suppression of NF-κB acvaon. Mut. Res./
Fund. Mol. Mech. Mutagen. 480–481: 243–268.
Świeca, M., Gawlik-Dziki, U., Kowalczyk, D., and Złotek, U. (2012). Impact
of germinaon me and type of illuminaon on the anoxidant com-
pounds and anoxidant capacity of Lens culinaris sprouts. Sci. Hor-
cul. 140: 87–95.
Tabas, I., and Glass, C.K. (2013). An-Inammatory Therapy in Chronic
Disease: Challenges and Opportunies. Science 339(6116): 166–172.
Takeoka, G.R., Dao, L.T., Tamura, H., and Harden, L.A. (2005). Delphinidin
3-O-(2-O-β-D-glucopyranosyl-α-L-arabinopyranoside): A novel an-
thocyanin idened in beluga black lenls. J. Agric. Food Chem.
53(12): 4932–4937.
Teklehaymanot, T., Giday, M., Medhin, G., and Mekonnen, Y. (2007).
Knowledge and use of medicinal plants by people around Debre Li-
banos monastery in Ethiopia. J. Ethnopharmacol. 111(2): 271–283.
Journal of Food Bioactives | www.isnff-jfb.com 103
Zhang et al. Phytochemicals of lentil (Lens Culinaris)
Thavarajah, D., Thavarajah, P., Sarker, A., and Vandenberg, A. (2009). Len-
ls (Lens culinaris Medikus Subspecies culinaris): a whole food for in-
creased iron and zinc intake. J. Agric. Food Chem. 57(12): 5413–5419.
Villegas, R., Gao, Y.-T., Yang, G., Li, H.-L., Elasy, T.A., Zheng, W., and Shu,
X.O. (2008). Legume and soy food intake and the incidence of type 2
diabetes in the Shanghai Women’s Health Study. Amer. J. Clin. Nutri.
87(1): 162–167.
Wu, J., Li, J., Cai, Y., Pan, Y., Ye, F., Zhang, Y., Zhao, Y., Yang, S., Li, X., and
Liang, G. (2011). Evaluaon and Discovery of Novel Synthec Chal-
cone Derivaves as An-Inammatory Agents. J. Med. Chem. 54(23):
8110–8123.
Xu, B., and Chang, S. (2007). A comparave study on phenolic proles and
anoxidant acvies of legumes as aected by extracon solvents. J.
Food Sci. 72(2): S159–S166.
Xu, B., and Chang, S.K. (2009). Phytochemical proles and health-promot-
ing eects of cool-season food legumes as inuenced by thermal
processing. J. Agric. Food Chem. 57(22): 10718–10731.
Xu, B., and Chang, S.K. (2010). Phenolic substance characterizaon and
chemical and cell-based anoxidant acvies of 11 lenls grown in
the Northern United States. J. Agric. Food Chem. 58(3): 1509–1517.
Xu, B., and Chang, S.K. (2012). Comparave study on anproliferaon
properes and cellular anoxidant acvies of commonly consumed
food legumes against nine human cancer cell lines. Food Chem.
134(3): 1287–1296.
Xu, B., and Chang, S.K.C. (2008). Eect of soaking, boiling, and steaming on
total phenolic contentand anoxidant acvies of cool season food
legumes. Food Chem. 110(1): 1–13.
Yeo, J., and Shahidi, F. (2015). Crical Evaluaon of Changes in the Rao of
Insoluble Bound to Soluble Phenolics on Anoxidant Acvity of Len-
ls during Germinaon. J. Agric. Food Chem. 63(2): 379–381.
Zhang, B., Deng, Z., Ramdath, D.D., Tang, Y., Chen, P.X., Liu, R., Liu, Q.,
and Tsao, R. (2015). Phenolic proles of 20 Canadian lenl culvars
and their contribuon to anoxidant acvity and inhibitory eects
on α-glucosidase and pancreac lipase. Food Chem. 172: 862–872.
Zhang, B., Deng, Z., Tang, Y., Chen, P., Liu, R., Ramdath, D.D., Liu, Q., Her-
nandez, M., and Tsao, R. (2014a). Fay acid, carotenoid and tocoph-
erol composions of 20 Canadian lenl culvars and synergisc con-
tribuon to anoxidant acvies. Food Chem. 161: 296–304.
Zhang, B., Deng, Z., Tang, Y., Chen, P.X., Liu, R., Ramdath, D.D., Liu, Q.,
Hernandez, M., and Tsao, R. (2014b). Eect of domesc cooking on
carotenoids, tocopherols, fay acids, phenolics, and anoxidant ac-
vies of lenls (Lens culinaris). J. Agric. Food Chem. 62(52): 12585–
12594.
Zhang, B., Deng, Z., Tang, Y., Chen, P.X., Ramdath, D.D., Liu, R., Liu, Q., Her-
nandez, M., and Tsao, R. (2017). Bioaccessibility, in vitro anoxidant
and an-inammatory acvies of phenolics in cooked green lenl
(Lens culinaris). J. Funct. Foods 32: 248–255.
Zou, Y., Chang, S.K., Gu, Y., and Qian, S.Y. (2011). Anoxidant acvity and
phenolic composions of lenl (Lens culinaris var. Morton) extract
and its fracons. J. Agric. Food Chem. 59(6): 2268–2276.
Zupfer, J., Churchill, K., Rasmusson, D., and Fulcher, R. (1998). Variaon in
ferulic acid concentraon among diverse barley culvars measured
by HPLC and microspectrophotometry. J. Agric. Food Chem. 46(4):
1350–1354.
... Lentils also contain dietary fiber, as well as minerals such as iron, folate, magnesium, and zinc [2]. Because of these considerations, lentils have long been recognized as a low-cost, high-quality alternative to animal proteins, earning the term "poor man's meat" [3], and they are regarded as a whole food supply for persons suffering from micronutrient malnutrition. Canada is the world's top lentil exporter, selling to more than 100 countries each year and accounting for over a quarter of global output. ...
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... It has been demonstrated that replacing wheat flour in the preparation of bread with 10%, 20%, and 30% of chickpea flour gives an acceptable bread for mass, size and sensorial characteristics (Simona et al., 2015). Additionally, lentils are well known for their content of health-promoting bioactive compounds, including starch and proteins (Zhanga, Penga, Denga, and Rong, 2018). Traditionally, lentils seeds and flours are used in the culinary art as an alternative of meet or proteins (Zhanga et al., 2018). ...
... Additionally, lentils are well known for their content of health-promoting bioactive compounds, including starch and proteins (Zhanga, Penga, Denga, and Rong, 2018). Traditionally, lentils seeds and flours are used in the culinary art as an alternative of meet or proteins (Zhanga et al., 2018). Other legume flours can be used in different applications, such as lentils, soya and lupin flours (Lee, Min, Choe, & Min, 2003;Paraskevopoulou, Chrysanthou, & Koutidou, 2012). ...
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... Regular intake of lentils or lentil-based products also provides a protective effect against various chronic disease conditions, for example, cardiovascular diseases, high blood pressure, high cholesterol, and cancer. Whole lentil or lentil flour of some lentil cultivars (e.g., Blaze and Laird) binds bile salts that is known to reduce blood cholesterol (Alshikh et al., 2015;Zhang et al., 2018). Predating modern research conducted during the last few decades, lentil's health benefits were also mentioned in ancient treatment remedies (Faris & Attlee, 2017;Lardos, 2006). ...
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... It has been reported that flavonoids can be used as an antioxidant to effectively reduce the occurrence of oxidation reactions (Hernandez et al., 2009). At present, DPPH and FRAP methods based on the principles of hydrogen atom transfer and single electron transfer have been widely used in the evaluation of the antioxidant capacity of bioactive compounds (Bing et al., 2018;Huang et al., 2005;Kitts and Hu, 2010). In addition, it has been reported that the antioxidant capacity of flavonoids varies greatly from species to species due to the diversity of their constituents (Mendes et al., 2012). ...
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