Variable 2: Jornada Escolar Regular
III. Resultados
The protein in legumes varies considerably, but legumes have generally high protein contents when compared to all other plant foods, thus they are characterized as ‘the poor man’s meat’ (Duranti & Gius, 1997). The lowest protein content, among the most common legumes cultivated for human consumption, have been observed for the common chickpea, being less than 15 % on dry matter basis in some cases (Monti & Grillo, 1983; Mesquita &
Giada, 2005). Among all legumes, the soybean is the one with the highest protein content, varying for mature seed from 32 % up to 50 % (Table 2; Karr-Lilienthal et al., 2004). High protein content is one of the main reasons why the soybean is the broadest cultivated legume (Duranti, 2006). Lupins (Lupinus spp.) also have a very high protein content, similar to soybean (Ródriguez-Ambriz et al., 2005), reaching up to 45.4 % (Ruiz & Sotelo, 2001).
Another high protein-containing legume is the jackbean Canavalia spp. whose protein levels often exceed 35 % (Rajaman & Janardhanan, 1992; Arun et al., 2003;)
Table 1. List of pulses’ world production in 2004 according to FAO
Grain legumes Latin names World crop production in
metric tones x 10-3 Dry beans (including Vigna
spp.)
Phaseolus spp.
Vigna spp.
1162
Dry broad bean Vicia faba 255
Dry peas Pisum sativum 892
Chickpea Cicer arietinum 478
Cowpea Vigna unguiculata 350
Pigeon pea Cajanus cajan 103
Lentil Lens culinaris 199
Vetch Vicia sativa 99
Lupins Lupinus spp. 45
Soybean Glycine max 6209
Table adapted from Duranti (2006)
Demetra Nikolopoulou and Kriton Grigorakis 108
Depending on oil content, we could say that soybean is an oilseed, with its oil contents varying from 12.8 % (Obatulu & Osho, 2006) up to 28.5 % (Dardanelli et al., 2006). Two local Nigerian legumes Afzelia africana and Pentsclethra macrophylla are also oilseeds with oil levels higher than 30% (Aja & Madubuike, 1997). All other legumes contain significantly lower oil contents, less than 10 % (Table 2). Among them, higher oil contents have been observed for lupins. Ródriguez-Ambriz et al. (2005) have mentioned ranges of 20%, although most of the literature (Table 2) shows lower oil contents in lupins, not exceeding 15% (Porres et al., 2006).
Proximate composition varies considerably not only among the various legumes, but also within the same genus (Table 2). Furthermore, significant compositional differences have been observed even within varieties, cultivars, or genotypes of the same species, for pigeon pea Cajanus cajan (Amarteifio et al., 2002; Fasoyiro et al., 2006; Marinder et al., 2007), chickpea Cicer arietinum (Nikolopoulou et al., 2006), jackbean Canavalia ensiformis (Alejandra et al., 1997), cassia Cassia obtusiflora (Vavidel & Janardhanan, 2005), soybean Glycine max (Vasconcelos et al., 1997; Giami, 2002; Kumar et al., 2006; Obatulu & Osho, 2006; Vasconcelos et al., 2006;), lentil Lens culinaris (Wang & Daun, 2006), narrow-leafed lupin Lupinus angustifolius (Frazer et al., 2005), Bengal bean Mucuna pruriens (Pugalenthi et al., 2005), common bean Phaseolus vulgaris (Yoshida et al., 2005), Tepary bean P.
acutifolius (De Mejia et al., 2005), Lima bean P. lunatus (Giami, 2001; Betancur-Ancona et al., 2003), field pea Pisum sativum (Al-Karaki & Erefej, 1999; Hickling, 2003; Yemane &
Skjelvåg, 2003; Wang & Daun, 2004; Nikolopoulou et al., 2007), African yam bean Sphenostylis stenocarpa (Oniyeike & Omubo-Dede, 2002), faba bean Vicia faba (Hossein &
Mortuza, 2006), grass pea Lathyrus sativa (Hanbury et al., 2000), and cowpea Vigna unguiculata (Giami et al., 2001; Ojimelukwe, 2002). The former show that proximate composition of legumes is strongly regulated by genetic factors.
The nutritional value of proteins from a large number of legumes (pigeon pea, jackbean, chickpea, common bean, cowpea, faba bean, lentils, lupins, mung bean, pigeon pea, rice bean, soybean, lentil, white lupin, field pea, lima bean, Phaseolus mungo, common bean, faba bean, Vicia angustifolia, cowpea) has been reviewed (Friedman, 1996; Duranti & Gius, 1997;
Phillips et al., 2003).
The major proteins of legumes can be traditionally classified, based on their solubility properties, into albumins, globulins, and prolamins. Among them, globulins, being storage proteins, are the most abundant legume proteins consisting the 70% of total protein in legumes. (Duranti, 2006)
The legumes’ seed proteins are relatively low in sulphur-containing amino acids and tryptophan. A very rich literature exists on amino acid composition of various legumes and focuses on their deficiencies in sulfur amino acids. Also some literature reviews are available on this subject, although not very recent ones (Monti & Grillo, 1983; Deshpande, 1992;
Duranti & Gius, 1997).
Chickpea (Cicer arietinum) proteins were found rich in essential amino acids such as isoleucine, lysine, and total aromatic amino acids (El-Adawy, 2002; Hickling, 2003; Iqbal et al., 2006). However, leucine and sulfur amino acids, threonine and valine were slightly deficient when compared to the general nutritional requirements (Table 3). Similar deficiencies have been reported for field peas (Alonso et al., 2000; Yemane & Skjelvåg, 2003; Wang & Daun, 2004), soybeans (Vasconcelos et al., 1997; Karr-Lilienthal et al., 2004;
Mahmoud et al., 2006; Vasconcelos et al., 2006), and various beans (Phaseolus spp.)
Nutritional and Antinutritional Composition of Legumes and Factors Affecting It 109 (Koehler et al., 1987; Duranti & Gius, 1997; Siddhuraju et al., 2001). The amino acid profile of Lupinus campestris flour is characterized by low methionine and high lysine contents (Rodríguez-Amriz et al., 2005). In all lupins the limiting amino acids are the sulfur ones (methionine and cysteine) (Ruiz & Sotelo, 2001). In lentils Lens culinaris tryptophan was found to be the first limiting amino acid followed by the sulphur containing amino acids (Wanf & Daun, 2006). Pigeon pea Cajanus cajan proteins are deficient in methionine and tryptophan (Friedman, 1996). Canavalia proteins are low in methionine and cysteine and high in lysine (Rajaram & Janardhanan, 1992; Eknayake et al., 1999). Other findings on Canavalia species partly contradict, showing lysine to be the first limiting amino acid in C. virosa and the second limiting amino acid after cysteine and methionine in C. ensiformis and C. gladiata (Siddhuraju & Becker, 2001; Vavidel & Janardhanan, 2005). In velvet beans (Mucuna spp.) the contents of threonine, lysine and leucine in black seed coat varieties and phenylalanine and tyrosine in white colored seed coat varieties seem to be deficient (Pugalenthi et al., 2005).
Beyond the limiting amino acids the nutritive value of legume proteins is further reduced by low digestibility, low bioavailability of essential amino acids and by the presence of toxic and antinutritional factors (Friedman, 1997; Phillips et al., 2003). It has been shown that the utilization, by non-ruminant mammals, of certain amino acids from legumes is limited (Friedman, 1996). Thus, methionine was not fully available to rats from any of chickpeas, faba beans and lentils, while threonine was not fully available from chickpeas and arginine and lysine was not fully available from faba beans (Combe et al., 1991). The formations of undigestible protein complexes by legume components influence amino acid utilization (Friedman, 1996) and in general legumes show a compact proteolysis-resistant structure of seeds (Duranti & Gius, 1997). The role of antinutritional factors is going to be discussed later.
The nutritional deficiency of legumes, due to the low sulfur amino acid levels, can be overcome by the complimentary use of cereal grains. In cereals lysine, present at high levels in legumes, is the limiting amino acid, and sulfur amino acids, deficient in legumes, is contained in high proportions (Friedman, 1996). The complement of legumes and cereals seems to have been known even in Neolithic human populations (Zohary & Hopf, 2000)
The fatty acid composition of the most common legumes is presented in table 4. Legumes are rich in polyunsaturated fatty acids (PUFAs) and in particular in linoleic acid (18:2) which in the cases of chickpea, field pea, lentil and Gila bean consist of about 50% of the total fatty acid contents (Siddhuraju et al., 2001; Amir et al., 2007). Polyunsaturated fatty acid are important for human health, seriously contributing to reduction of coronary disease risk and having immunologic and anti-inflammatory effects (Simopoulos, 2002)
In general, beyond the linoleic acid the other dominant fatty acids of legumes are palmitic acid (16:0) and oleic acid (18:1). The Canavalia spp. are also rich in linolenic acid (18:3), an essential fatty acid that is converted to eicosapentaenoic (20:5, EPA) and in turn docohexaenoic acid(22:6, DHA) (Sridhar & Seena, 2006).
The carbohydrates of legumes can be classified into low-molecular weight carbohydrates, which include mono- di and oligosaccharides, and polysaccharides (Asp, 1996). The main form of oligosaccharide met in the legumes is the raffinose series oligosaccharides (RSO).
The polysaccharides can be divided into starches, which are linear (amylose) or branched (amylopectin) glucose homopolymers, and non-starch polysaccharides (NSP) (Asp, 1996).
The NSP can be divided into dietary fibre (plant cell wall NSP, consisting mainly of cellulose, and a range of heteropolysaccharides withouth α-glucosidic linkages) and others (Asp, 1996; Englyst & Hudson, 1996).
Table 2. Proximate composition of various legumes used for human foods, from various regions in the world Scientific name Common
name
Ash Origin notes References
Afzelia africana
15.0-16.6
Nigeria 2 areas, dehulled seeds
Aja & Madubuike, 1997 Atylosia
scarabaeoides
17.3 4.56 8.21 3.18 India Arinathan et al., 2003
Brachystegia
8.75-10.0
Nigeria 2 areas, dehulled seeds
Aja & Madubuike, 1997
eurycoma 11.8 5.87 /57.8 17.0 3.68 Nigeria whole seeds Ajayi et al., 2006
Cajanus cajan Pigeon pea, 19.0-21.7
1.2-1.3 9.8-13.0
3.9-4.3 Botswana 6 varieties Amarteifio et al., 2002 Red gram
India 2varieties, seed flour
Maninder et al., 2007 Fasoyiro et al., 2006 29.3 2.36 41.3/ 39.1 3.99 Venezuela Torres et al., 2007 Cicer arietinum Chickpea 14.9 -
29.6
Monti & Grillo, 1983 De Almeida Costa et al., 2006
Nikolopoulou et al., 2006
Christodoulou et al., 2005
23.6 6.48 62.3 3.82 3.72 Egypt El-Adawy, 2002
24.0 5.2 3.6 Pakistan Iqbal et al., 2006
Scientific name Common
Ash Origin notes References Canavalia C .ensiformis jackbean
26.3-35.0
India Rajaman & Janardhanan, 1992
Siddhuraju & Becker, 2001
Arinathan et al., 2003 Vavidel & Janardhanan, 2005
Aja & Madubuike, 1997 31.4 8.10 2.93 Venezoula 5 genotypes Alejandra et al., 1997 C. gladiata swordbean
12.9-35.0
India Rajaman & Janardhanan, 1992 Siddhuraju &
Becker, 2001
Vavidel & Janardhanan, 2005
Vavidel & Janardhanan, 2004
Table 2. Continued Scientific name Common
name
Crude protein
Oil Starch /CHO
Crude fiber
Ash Origin notes References
Cassia spp. Cassia 32.3 17.6/ Korea wild Shim et al., 2003
Cassia floribunda
21.7 3.1 /61.0 10.8 3.4 S. India Vavidel & Janardhanan, 2005
C. obtusifolia
18.6-22.9
5.35-7.40
/60.3 6.83-9.45
5.14-5.83
S. India
4 assecions
Vavidel & Janardhanan, 2002
Vavidel & Janardhanan, 2005
Entada phaseoloides Merril
Gila bean 34.1* 7.16* 8.53* 2.49* India Siddhuraju et al., 2001
Glycine max soybean 32.6 23.3 Argentina Karr-Lilienthal et al.,
2004
36.0-48.5
19.7-23.2
/15.8-40.0
22.6 3.09-5.22
Brazil 5 local cv.
(mature) 9 cultivars (mature)
Vasconcelos et al., 1997 Karr-Lilienthal et al., 2004
Vasconcelos et al., 2006
44.9 23.4 China Karr-Lilienthal et al.,
2004
37.5-39.6
15.4-22.0
22.4-24.9
India 7x3 (cv. x locations)
Karr-Lilienthal et al., 2004
Kumar et al., 2006
Scientific name Common
Ash Origin notes References
Nigeria 3 cultivars (mature) 1 cultivar (mature)
Giami, 2002
Obatolu & Osho, 2006
Obatolu & Osho, 2006
37.1 22.4 U.S. Karr-Lilienthal et al.,
various Green (immature) Redondo-Cuenca et al., 2006
various Yellow (matured) Lablab
purpureus
lablab 24.8 8.33 3.21 3.99 India var. lignosus Arinathan et al., 2003 Lathyrus cicera Flat pod pea
vine
21.7-33.0
0.7-1.4 44.2 6.7-7.3 2.9-3.8 various 4 cultivars Hanbury et al., 2000 L. sativus Chickling
pea, grass
2.0-3.9 various 10 cultivars Hanbury et al., 2000
Lens esculenta or
lentil 25.0 - 29.3
Monti & Grillo, 1983
Lens culinaris
25.9-28.7
Table 2. Continued Scientific name Common
name
Crude protein
Oil Starch /CHO
Crude fiber
Ash Origin notes References Lupinus albus White lupin 17.0 –
38.7
Monti & Grillo, 1983
32.2 6.0 14.5 3.1 Wiryawan, 1997
38.1 4.52 31.6 17.1 3.59 S. Africa Brand et al., 2004
34.4 14.6 3.51 Spain Porres et al., 2006
L. angustifolius Narrow- 30.0-35.8
5.4 -5.6
3.7 -
3.8
U.K. 2 varieties Frazer et al., 2005 leafed lupin 33.8 4.52 /34.6 24.3 3.3 S. Africa Brand et al., 2004
L. elegans 45.4 5.79 /31.7 12.9 4.20 Mexico Ruiz & Sotelo, 2001
L. exaltatus
38.4-40.5
8.5 /32.8 14.6-18.5
3.59-3.8
Mexico wild Ruiz-López et al., 2000 Ruiz & Sotelo, 2001 L. luteus Yellow
lupin
39.3 5.35 /28.0 20.2 4.52 S. Africa Brand et al., 2004
L. madrensis 41.5 6.80 /32.8 15.4 3.51 Mexico wild Ruiz & Sotelo, 2001
L. mexicanus 36.7 16.8 4.11 Mexico wild Ruiz-López et al., 2000
L. reflexus
37.3-38.8
7.90 /34.6 15.2-16.6
3.61-7.22
Mexico wild Ruiz-López et al., 2000 Ruiz & Sotelo, 2001
L. rotundiflorus 42.8 5.50 /32.6 15.1 4.01 Mexico wild Ruiz & Sotelo, 2001
L. simulans 40.7 6.29 /35.0 14.4 3.59 Mexico wild Ruiz & Sotelo, 2001
L. splendens 37.2 8.89 /38.1 12.7 3.30 Mexico wild Ruiz & Sotelo, 2001
Mucuna monosperma
M. flagellipes 24.9 3.77 /39.2 16.5 6.22 Nigeria whole seeds Ajayi et al., 2006
Scientific name Common
Ash Origin notes References M. pruriens Bengal
bean,
26.2 4.6 7.9 4.5 India white bean, var.
utilis
Pugalenthi et al., 2005 Cow itch 24.3 4.9 7.0 3.8 India black bean, var.
Siddhuraju & Becker, 2005
Arinathan et al., 2003 Pentaclethra
Nigeria 2 areas, dehulled seeds
Aja & Madubuike, 1997 Phaseolus
vulgaris
Kidneybean, 17.0 - 39.4
Monti & Grillo, 1983 common
Brazil Mesquita & Giada, 2005 De Almeida Costa et al., 2006
white bean 21.4-23.1
43.5/60.7 16.4 3.79-4.54
Mexico De Mejia et al., 2005 Carmona-Garcia et al., 2007
21.5 1.4 22.2 Unspec. Kahlon et al., 2005
Table 2. Continued Scientific name Common
name
Ash Origin notes References Phaseolus Fasoyiro et al., 2006 Phasulas aureus Mung bean 26.4 1.75 53.0/61.2 6.15 4.50 Egypt var. V.C 2010 El-Adawy et al., 2003 Pisum sativum Field pea, 15.5 -
39.7
Monti & Grillo, 1983 dry pea,
Brazil Mesquita & Giada, 2005 De Almeida Costa et al., 2006 Reichert & MacKenzie, 1982
Ethiopia 2 cultivars Yemane & Skjelvåg, 2003
Nikolopoulou et al., 2007
24.9 1.5 3.6 Pakistan Iqbal et al., 2006
Al-Karaki & Ereifej,1999
Scientific name Common
Ash Origin notes References Rhynchosia
Nigeria 2 varieties
2 varieties
Onyeike & Omubo-Dede, 2002
Achinewhu & Akah, 2003 Fasoyiro et al., 2006 Tamaridus
indica
Tsamiya 24.3 7.20 /38.3 18.0 1.50 Nigeria whole seeds Ajayi et al., 2006 Vicia faba Faba bean, 22.0 -
37.0
Monti & Grillo, 1983 field bean, 25.5 2.7 53.2/ 15.4 5.1 India genotype
VH-82-1
Saharan et al., 2002 Horse bean 27.67 3.12 45.00 5.67 5.67 Pakistan local faba
(Kalimatar)
Hossein & Mortuza, 2006 Broad bean 27.17 3.29 46.16 1.12 5.46 Pakistan Exotic faba
Nigeria 4 varieties 3 varieties
Giami et al., 2001 Ojimelukwe, 2002 Achinewhu &Akah, 2003 pea 25.7 1.16 38.1 27.38 3.62 whole Ghavidel & Prakash, 2007
28.4 1.48 37.0 22.82 3.47 dehulled
15.9 4.55 4.56 3.18 India Arinathan et al., 2003
24.7 4.8 4.2 Pakistan Iqbal et al., 2006
V. mungo Black gram 22.0 1.1 11.4 Unspec. Kahlon et al., 2005
Table 2. Continued Scientific name Common
name
Crude protein
Oil Starch /CHO
Crude fiber
Ash Origin notes References
V. radiata Green gram 27.7 1.29 46.7 20.0 4.03 whole Ghavidel & Prakash, 2007
mung bean 29.9 1.7 44.8 15.16 3.79 Dehulled V. subterranean Bambara
groundnut
22.1 2.02 /55.63 2.31 3.97 Nigeria Fasoyiro et al., 2006
V. tilobata 20.2 12.3 7.24 3.89 India Arinathan et al., 2003
V. umbellata Rice bean 18.2 0.83 /50.7 21.5 5.0 India Saharan et al., 2002
All values are expressed as % of dry matter.
* Calculated from the compositional values provided for seed kernel and seed coat and the respective weight percentages of seed kernel and coat.
Table 3. Amino acid composition of legumes (g/16g N)
Nestares et al., 1996 El-Adawy, 2002
Eknayake et al., 1999 Siddhuraju & Becker, 2001
Yemane & Skjelvåg, 2003
Alonso et al., 2000 Wang & Daun, 2004 Gila bean 3.8 4.2 7.0 7.7 2.03 3.75 5.2 5.0 3.4 1.05 4.7 Siddhuraju et al., 2001 Wang & Daun, 2006 Lupinus
Table 3. Continued Mucuna utilis
4.2-4.8
Pugalenthi et al., 2005 Soybean
0.74 Vasconcelos et al., 1997 El-Moniem et al., 2000 Karr-Lilienthal et al., 2004
Mahmoud et al., 2006 Vasconcelos et al., 2006 FAO/WHO
*Calculated from the individual amino acids given in each reference.
** Calculated from amino acids % of dry matter given by the reference.
*** According to FAO/WHO, 1991.
† According to FAO/WHO/UNU, 1985.
Table 4. Fatty acid composition of legumes
0.05-0.5 1.4-2.5 18.2-20.2 Common bean
12.9-24.5
0.1-0.2 0.20 Pirman & Stibilj, 2003* Yoshida et al., 2005**
Gila bean 9.7 0.1 4.0 25.0 58.1 0.1 1.0 0.43 0.19 Siddhuraju et al., 2001 Canavalia gladiata
16.7-19.9
Siddhuraju & Becker, 2001
* Calculated from the individual mg FA / 100g dry sample given by the reference.
** Calculated from the percentages of individual fatty acids in polar lipid and triacylglycerol fractions and the relative amount of the these fractions.
Table 5. Carbohydrates of legumes. Expressed as percentage on dry mater basis Total
Starch
RS Dietary fibre NSP Sucrose RSO
IDF SDF raffinose stachyose verbascose Total Black
gram
11.4 0.3-0.8 0.3-0.8 1.12-3.32 Rao & Belavady, 1978 Grigowda et al., 2005 Kahlon et al., 2005 Bengal
gram
25.4 Kahlon et al., 2005
Canavalia spp.
Siddhuraju & Becker, 2001 C.
cathartica
32 9.0 22.6 0.96 Sridhar & Seena, 2006
C.
ensiformis 24.7-36.9
10.8 16.8 0.82 Siddhuraju & Becker, 2001
Sridhar & Seena, 2006 C.
gladiata
31.8-39.6
11.8-14.0
21.0-20.2
0.01-0.86
3.6 4.6 Eknayake et al., 1999 Siddhuraju & Becker, 2001
C. virosis 36.9 9.0 Siddhuraju & Becker, 2001
chickpea 39.4-53.2
3.39-4.35
13.1-13.9
9.82-13.4
15.58 0.8-3.0 0.8-1.8 3.34-14.4
Rao & Belavady, 1978 Farrell & Mannion, 1997 Saura-Calixto et al., 2000 De Almeida Costa et al., 2006
Fialho et al., 2006 Han & Baik, 2006 Nikolopoulou et al., 2006 Amir et al., 2007
Total Starch
RS Dietary fibre NSP Sucrose RSO
IDF SDF raffinose stachyose verbascose Total Common
bean
37.3-41.3
2.5-4.96 15.2-19.9
17.70 0.91-1.14
0.22-1.39
1.80-4.45 0.0-0.25 2.44-3.68
Kuo et al., 1988 Abdel-Gawad, 1993 Saura-Calixto et al., 2000 Kahlon et al., 2005 De Almeida Costa et al., 2006
Amir et al., 2007
Cowpea
1.14-1.51
0.52-0.77
3.00-3.74 0.30 4.07 Abdel-Gawad, 1993 Faba bean 53.2 21.5-25.0
10.9-16.0
0.99-1.37
0.52 1.46 1.85 3.78 Abdel-Gawad, 1993 Farrell & Mannion, 1997 Saharan et al., 2002 Field pea
33.4-47.5
2.45-10.0
17.8-20.3
8.7-19.5
19.96 6.23 0.56-0.92
1.60-2.31 1.4-2.83 5.0-7.28
Reichert & MacKenzie, 1982
Kuo et al., 1988
Farrell & Mannion, 1997 Saura-Calixto et al., 2000 Alonso et al., 2000 Hickling, 2003 Andersen et al., 2005 Urbano et al., 2005 De Almeida Costa et al., 2006
Han & Baik, 2006 Nikolopoulou et al., 2007
Gila bean 26.2 0.17 1.29 2.49 ND Siddhuraju et al., 2001
Table 5. Continued Total
Starch
RS Dietary fibre NSP Sucrose RSO
IDF SDF raffinose stachyose verbascose Total Lentils
1.65-3.74 0.45-0.62 2.71-6.46
Abdel-Gawad, 1993 Frias et al., 1996b Saura-Calixto et al., 2000 De Almeida Costa et al., 2006
3.45-7.26 0.19-3.54 5.24-12.3
Farrell & Mannion, 1997 Ruiz-López et al., 2000 Martínez-Villaluenga et al., 2005
Andersen et al., 2005 Mung Mulimani & Devendra, 1998 El-Moniem et al., 2000 Redondo-Cuenca et al., 2006
Velvet bean
27.8 10.1
0.95-1.10
1.05-1.22 3.95-4.34 Pugalenthi et al., 2005 ND: not detected.
Nutritional and Antinutritional Composition of Legumes and Factors Affecting it 125 The non-cellulosic NSP can be classified according to many different criteria, for example in neutral, acidic (containing mainly uronic acid residues) and hemicellulose A, B and C depending on their solubility at various pH. (Asp, 1996)
Starch is the polysaccharide, containing only α-glucosidic linkages, which quantitatively is the most important digestible carbohydrate. However, for nutritional purposes, it can be divided into rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) (Englyst & Hudson, 1996). The latter is a fraction that contributes, together with the NSP and oligosaccharides, to the undigestible carbohydrate fraction (Asp, 1996).
In table 5 the contents of the various carbohydrate fractions in legumes are presented.
Legumes in general are rich in both total carbohydrates and dietary fibre.
A strong variability has been observed for the various carbohydrate fractions even within the same legume species, especially regarding the measurement of dietary fibre and NSP.
This can be due to either varietal differences or the different methodologies adopted in each case. These different methodology approaches, giving differential results, have been discussed up to a degree (Monte & Maga, 1980; Asp, 1996; Englyst & Hudson, 1996).
Starch contents in legumes vary from negligible levels in soybean Glycine max and lupins to more than half of the dry seed weight in some legumes such as peas (Guillon &
Champ, 2002). Most starches from grain legumes have relatively high amylose content compared to other starches. Amylose content in legumes starch varies from 24 % of starch in faba bean (Guillon & Champ, 2002) up to 78.4 % in wrinkled peas (Zhou et al., 2004). With some exceptions (sphero-pyramidal starch of winkled peas), morphologically they are kidney-like or ovoid with well-defined shells centered along an elongated hilum (Guillon & Champ, 2002). The starches of various beans Phaseolus vulgaris (Yañez-Farias et al., 1997; Hoover &
Ratnayake, 2002; Zhou et al., 2004), beach peas Lathyrus maritimus (Chavan et al., 1999), chickpeas Cicer arietinum (Yañez-Farias et al., 1997; Hoover & Ratnayake, 2002; Huang et al., 2007), cowpeas Vigna unguiculata (Lecuona-Villanueva et al., 2006; Huang et al., 2007), grass peas Lathyrus sativus (Jayakody et al., 2007), lentils Lens culinaris (Hoover &
Ratnayake, 2002; Zhou et al., 2004), lima beans Phaseolus lunatus (Ancona et al., 2001), mung beans (Hoover et al., 1997), peas (Hoover & Ratnayake, 2002; Ratnayake et al., 2002;
Zhou et al., 2004; Huang et al., 2007; Tetchi et al., 2007) and soybeans Glycine max (Stevenson et al., 2006) have been well characterized.
The raffinose series oligosaccharides of various legumes are presented in table 5. Lentils and chickpeas also contain another oligosaccharide (not presented in the table), ciceritol (Gulewicz et al., 2000; Han & Baik, 2006), while lupins also contain small quantities (0.72-2.27 % of whole seed oligosaccharides) of another oligosaccharide, ajucose (Ruiz-López et al., 2000). Ciceritol is completely absent from peas and soybeans (Han & Baik, 2006).
The raffinose series oligosaccharides contents in legumes are known to increase with maturation progress (Frias et al., 1996; Ekvall et al., 2006) and they have been also related to the ability of legumes to survive dry periods (Bailly et al., 2001). Furthermore in peas, they also appear to be dependent on the seed size and density, generally being higher in larger and denser (sinking) peas (Ekvall et al., 2006). Karr-Lilienthal et al. (2005) in a study in 55 soybean processing plants, have shown differentiations in soybean oligosaccharides and total dietary fibre depending on the maturity zone and collection times. However, in all cases, there are serious indications that verbascose, raffinose and stachyose do not follow the same accumulation pattern (Karr-Lilienthal et al., 2005; Ekvall et al., 2006).
Demetra Nikolopoulou and Kriton Grigorakis 126
In general the legumes are rich in dietary firbe, which contents usually exceed 20 % of total dry weight, while in lupins they can reach up to 40% (Farrell & Mannion, 1997).
Insoluble fiber is the dominant fraction of fibre (Table 5) and consists more than 90% of the total amount of dietary fiber in beans and lentils (Bednar et al., 2001), as well as in Canavalia spp. (Sridhar & Seena, 2006). The composition of the dietary fibre fraction depends mostly on its localization in the seed coat or the cotyledons (Guillon & Champ, 2002). Dietary fiber is nutritionally one important aspect, due to its beneficial effect on bacterial colon population, its contribution on cholesterol reduction, its ability to absorb bile salt, and to prevent various diverticular degenerative diseases. The recommended daily intake of fiber is between 25 and 50 g (Sridhar & Seena, 2006). Unfortunately, dietary fiber intakes in Western countries only accounts to one third of the required substrates for colonic cell turnover. However, there is a recent tendency among nutritionists to extend the dietary fiber concept to include all the indigestible food constituents (i.e. those that reach the colon). Thus, it has arisen the, nutritionally more useful, concept of indigestible fraction, which includes besides the indigestible fiber, the resistant starch, the indigestible protein, certain polyphenols and other associated compounds (Saura-Calixto et al., 2000). There is a significant difference between the dietary fibre and the indigestible fraction contents, with the latter being sufficient to cover the requirements for the colon health (Table.6).
Recent reviews occur concerning the human nutritional and health aspects of legume proteins (Friedman, 1996; Duranti, 2006) and carbohydrates (Guillon & Champ, 2002;
Tharanathan & Mahadevamma, 2003)
Regarding the mineral contents of legumes, we won’t refer to them in detail, but in general legumes are rich in potassium and magnesium and consumption of even small quantities of less than a portion per day is sufficient to cover the adult recommended daily allowance for Mg, P and Fe (Wang & Daun, 2006). These micronutrients contents vary
Regarding the mineral contents of legumes, we won’t refer to them in detail, but in general legumes are rich in potassium and magnesium and consumption of even small quantities of less than a portion per day is sufficient to cover the adult recommended daily allowance for Mg, P and Fe (Wang & Daun, 2006). These micronutrients contents vary