Amino acid composition of storage proteins of a promising chickpea (Cicer arietinum L) cultivar

The amino acid compositions of flours made from the cotyledons and from the whole seeds of a disease-resistant, stable and high-yielding cultivar of chickpea (Cicer arietinum L) cv H75–35, known locally as Gaurav, have been analysed. These, together with similar analyses of the albumin, globulin, legumin and vicilin protein fractions, have been compared with those of other legumes. Seed protein content was 19·8 % with globulin constituting 62·4 % of the total seed protein. The ratios of albumin to globulin and legumin to vicilin were 1:4 and 6:1, respectively. The proportion of basic amino acids in the albumin was low whereas the reverse was true in the globulin. The legumin fraction seems to be superior in terms of total essential amino acids to those from other sources. Sulphur amino acids were the most limiting, followed by tryptophan or threonine depending on the fraction. However, the ratio of methionine to cystine was high (2·76:1). The extent of the sulphur amino acid deficiency was assessed, and possible approaches for its improvement are outlined.     

Nutritive value of some improved varieties of legumes.

The nutritional quality of some improved varieties of chick peas (Cicer arietinum), mash beans (Phaseolus mungo), mung beans (Phaseolus aureus) and cow peas (Vigna sinensis), grown in Pakistan, was measured chemically (including amino acid analyses) and biologically in N-balance experiments with growing rats. Lysine and total sulphur amino acids were lowered in varieties with a higher content of protein. The true protein digestibility (TD), biological value (BV) and net protein utilisation (NPU) of different varieties of chick peas, mung beans and cow peas varied between 85–89, 83–85 and 87–92%, 62–69, 54–56 and 55–59% and 55–60, 45–48 and 50–51%, respectively. The TD of protein was highest (89%) in chick peas, 6560 having a higher protein content (29.4%) while its BV was lowest (62%) as compared to the other varieties of chick peas. There was a significant correlation (r=0.97) between BV and the total sulphur containing amino acids and BV could be predicted from the regression equation; BV (%)= 33.03 + 10.56x methionine+cystine (g per 16 g N). This indicates that methionine+cystine are the first limiting amino acids in these varieties. Tannin content does not seem to affect the TD of mash and mung beans.     

Assessment of protein fractions of three cultivars of <Emphasis Type="Italic">Pisum sativum</Emphasis> L.: effect of germination

Protein composition, nitrogen and amino acid content of Osborne fractions in different cultivars of Pisum sativum L. (cv. ucero, cv. ramrod and cv. agra) seeds were investigated and the effect of germination on these parameters was also analysed. Albumins comprised the main protein fraction in raw seeds, globulins were constituted mainly by vicilin, with a smaller proportion of the glutelin and prolamine fractions. Regarding the amino acid profile of pea protein fractions, although differences among pea cultivars were found, in general albumin, glutelin and prolamine fractions presented Asp, Glu and Gly as the major non-essential amino acids (NEAA) and Lys as the main essential amino acid (EAA). The globulin fraction, however, presented Asp, Glu, Gly and Arg as the major NEAA and Leu, Phe, Lys, and Thr as the main EAA. In general, the albumin fraction accounted for more sulphur amino acids and Lys, followed by the glutelin + prolamine fraction. Germination caused an increase in the total protein content of P. sativum cv. ucero and P. sativum cv. ramrod. In the albumin fraction a wide number of proteins underwent degradation and convicilin disappeared from the globulin fraction of pea sprouts whilst vicilin and legumin decreased slightly. In general, all the Osborne fractions of pea sprouts presented higher EAA contents than raw seeds. The estimated essential amino acid indexes of protein fractions for P. sativum cv. ucero (EAAI_adult and EAAI_egg) improved with the germination process whilst for P. sativum cv. ramrod and P. sativum cv. agra depended on the Osborne fraction.     

Crude protein and sulphur amino acid contents of some commercial varieties of peas and beans

Spring field bean varieties contain more protein than peas, but fluctuating yields often confuse results. Peas have a higher sulphur amino acid content than beans, but potential sulphur amino acid yield ha^?1 is greater in the latter. The biological value in rat feeding trials closely reflected the sulphur amino acid content. A negative correlation was found between protein sulphur amino acid content and percentage seed protein.     

Protein classification of beach pea (Lathyrus maritimus L.)

Protein fractionation of whole seed, cotyledons and hulls of beach pea (Lathyrus maritimus L.) was carried out. Surface topography of pea protein isolates and protein fractions, as well as their polyacrylamide gel electrophoresis (PAGE), was studied. The nitrogen solubility of beach pea seed meal was minimum at pH 4.5. Globulin was the major protein fraction present and its content in whole seeds (57%), cotyledons (62%) and hulls (24%) of beach pea was lower than those of other common pea cultivars; the same was true for its albumin content. However, glutelin content in beach pea seed and its parts (cotyledons and hulls) was higher than those of other pea cultivars. The albumin fraction contained the highest amount of total sulphur-containing amino acids followed by glutelin, globulin and prolamine. The amount of sulphur-containing amino acids in beach pea protein fractions was higher than in other peas. Predicted biological value of albumin and glutelin fractions of beach pea was also higher than green pea and grass pea. Beach pea seed protein fractions showed different UV spectra from other pea cultivars. Protein isolate and protein fractions of beach pea seeds showed similar topographical characteristics to those of other peas. Major polypeptide bands in the range of 35–47 kDa in the protein isolate, as well as protein fractions for beach pea, were detected by PAGE.     

Nutritional potential and functional properties of tempe produced from mixture of different legumes. 1: Chemical composition and nitrogenous constituent

Fermented foods such as Tempe represent a technological alternative for a great variety of legumes and combination of them to improve their nutritional quality and to obtain edible products with palatable sensorial characteristics. The chemical composition, carbohydrate fraction and nitrogenous constituents were investigated for individual different legumes, i.e. faba bean; lupine, chickpea; peas and their mixture before and after fermentation by Rhizopus oligosporus. Tempe had a higher (P < 0.05) protein and fibre content compared with legume mixtures before fermentation, while it had a lower fat, ash and carbohydrate contents. Also, reducing and non‐reducing sugars, stachyose as well as raffinose were reduced after fermentation of legume mixtures. A significant reduction was observed in non‐protein nitrogen and protein nitrogen, while total nitrogen and true protein were increased.     

Major albumins of Pisum cotyledons

The albumin fraction of the cotyledons of Pisum contains two major polypeptides which together make up 34% (17% each) of the total albumin fraction. Both of these albumins (M_r～8000 and ～22000) are cotyledon specific proteins. In many Pisum lines the M_r～22000 fraction resolves into two components on Na-dodecylsulphatepolyacrylamide gels. The M_r～8000 polypeptide was broken down during germination and early seedling growth, indicating that it functions as a storage protein, while the M_r～22000 polypeptides were degraded relatively slowly. The level of both of these polypeptides was markedly reduced under sulphur deficiency conditions, the M_r～22000 components being affected to a lesser extent than the M_r～8000 component. Consistent with this, when [³⁵S]sodium sulphate was injected into the pedicel of control plants during seed development and albumins were isolated at seed maturity, polypeptides of M_r～8000 and ～22000 together accounted for a major proportion of the radioactivity in the total albumin fraction. The abundance and relatively high sulphur content of these two albumins could be significant factors in determining the nutritional value of pea seed proteins.     

Nutritional value of cooked beans (Phaseolus vulgaris) and their isolated major protein fractions

The digestibility and nutritional properties of whole cooked beans (Phaseolus vulgaris L) and their isolated and cooked major protein fractions were evaluated in rats. Isolated globulin GI was highly digestible (89.5%) but had a low NPR value (1.51). The albumins and glutelins exhibited intermediate digestibilities (79.1 and 73.2%) and a biological utilisation NPR of 3.18 and 2.91, respectively, 30% lower than casein. Whole beans exhibited the poorest digestibility (62.8%) with a faecal excretion of more than 30% of the ingested nitrogen and an intermediate NPR of 2.27. There was a direct relation between the amount of ingested dietary fibre and dry matter and N excretion. Enrichment of whole beans with the isolated albumin fraction, rich as it is in sulphur amino acids, did not improve NPR value. Dry beans apparently contain components producing undigestible protein complexes which affect amino acid availability and increase endogenous nitrogen excretion.     

Characterization of protein fractions from chickpea (Cicer arietinum L.) and oat (Avena sativa L.) seeds using proteomic techniques

Albumin, globulin and glutelin fractions were prepared from chickpea and oat seeds using sequential extractions. Molecular characteristics of individual protein fractions were investigated using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) in combination with proteomic techniques. SDS-PAGE results revealed that chickpea albumin and globulin fractions (C-Ab and C-Gb) showed protein bands with molecular weights (MWs) related to subunits of legumin (11S globulin) and pea vicilin (7S globulin); oat protein fractions (O-Ab, O-Gb and O-Gt) showed most protein bands with MWs related to subunits of oat 12S globulin (avenalin). With proteomic analysis, eighteen tryptic peptides from chickpea globulin fraction showed sequence homology that corresponded to chickpea legumin α- and β-subunit (NCBI accession number: gi|6273402; theoretical mass 56,216 Da) while sixteen tryptic peptides from chickpea albumin fraction (C-Ab) were identified as chickpea provicilin precursor (NCBI accession number: gi|82173888; theoretical mass 51,390 Da); fifteen tryptic peptides from oat protein fractions were identified with origin from oat 12S seed storage globulin 1 (NCBI accession number: gi|134918; theoretical mass 58,508 Da). The identified tryptic peptide, ALIVPQNFAIAAK, was commonly found in chickpea glutelin fraction (C-Gt), rice glutelin fraction (R-Gt), and oat albumin, globulin and glutelin fractions (O-Ab, O-Gb and O-Gt).     

Quantitative and qualitative variability of pea (Pisum sativum L.) protein composition

Smooth and wrinkled pea cultivars were studied to evaluate the protein content of the seeds, the proportion of albumins to globulins and the variability of the vicilin/legumin ratio. Principal components analysis showed a strong negative correlation between albumin and globulin contents. Stepwise discriminant analysis demonstrated that two variables, protein content and vicilin/legumin ratio, divided the samples into smooth and wrinkled cultivars with a percentage of success of 95%. In addition, the vicilin/legumin ratio tended to increase, the lower the protein content is.     

Soluble Albumin and Biological Value of Protein in Cocoa (Theobroma cacao L.) Beans as a Function of Roasting Time

ABSTRACT: An association has been identified between the extent of roasting and the amount of extractable protein from the cocoa bean, its nutritive value, and the sensorial quality of the liquor. Cocoa nibs from fermented seeds ( Theobroma cacao L.) were precision-roasted at 150°C for 0, 30, 34, 38, 42, and 46 min and the protein fraction extracted. From the beginning of roasting, until minute 38, about 87% of the proteins were extractable, but the extractability substantially decreased to 72.7% at 42 min and to 65.3% at 46 min. Both total soluble protein determination and albumin concentration of the roasted nibs diminished slightly until minute 38, when acceptable sensory characteristics were obtained for the liquor. Both total nitrogen and capillary-electrophoretic separation and quantification of the albumin showed that the amounts of extractable protein in this fraction consistently followed a cyclic pattern until minute 42, irreversibly decreasing thereafter. Biological evaluation of the protein from the cocoa nibs roasted for the various times showed that at the point that the sensory rating approached that of a commercial liquor, the albumin content and nutritive value were still high. The findings suggest that with moderate, uniform roasting it may not be necessary to sacrifice the protein's biological value for the sensorial attributes of chocolate in a standard commercial roast.     

Chemical methods suitable for screening for protein content and quality in cowpea (Vigna unguiculata) meals

Several chemical methods have been tested for their suitability as screening procedures for estimation of the protein content and quality of cowpea (Vigna unguiculata) meals. Preliminary estimates of crude protein can be obtained by the UDY dye-binding procedure, followed by the automated microKjeldahl (% N × 6.25) method using, for example, Carlo Erba equipment. Total amino acid nitrogen was estimated also with the Carlo Erba apparatus and for the cowpea varieties examined a positive correlation between the total amino acid nitrogen and total nitrogen contents was found. Total sulphur was evaluated as a measure of the sulpho-amino acids in cowpea meals. Total sulphur was determined by wet digestion and subsequent turbidimetric estimation of barium sulphate. Methionine was determined in meal hydrolysates by a Locarte Autoanalyzer. Cysteine was determined either as cysteic acid on the Locarte Autoanalyzer or as bismuth sulphide. The results obtained for cowpea meals showed that there was a relatively small variation in the total sulphur and in the sulpho-amino acid contents. Although the relation between total sulphur and sulpho-amino acids was found to be significant at the 95% confidence level, the confidence limits were wide and at this stage a definite recommendation cannot be given as to the probable usefulness of the total sulphur-screening procedure. A strong negative correlation was observed between both methionine and sulpho-amino acids/16 g of N and % crude protein. Similarly, a negative relationship was observed between total sulphur/16 g of N and % crude protein.     

Effects of commercial canning on SDS-PAGE patterns of the albumin fraction of four pea sizes

Size has been related with pea seed growth and maturation [1], and it is also considered an important parameter when peas are chosen for canning [2]. Some changes occur in the composition of vegetables during blanching, which are the partial loss of major components [3], that are further reduced during canning, mainly due to leaching into the water used for processing [4]. This leaching can be significant if the brine is discarded and not used as a part of the food consumed, as it is often done with most of canned vegetables [5]. Pea seed is an important source of protein for humans, and it has been suggested [6] that when considering pea seeds protein quality more emphasis should be given to the study of the albumin fraction, because it is the fraction rich in the sulphur amino acids. Although electrophoretic analysis of heat-treated proteins can be considered as time consuming it has been used to monitor changes in specific proteins and mixtures of protein subjected to a variety of heat treatments [7]. In general, heat treatments result in a drastic change in polyacrylamide gel electrophoresis (PAGE) patterns in the presence of the detergent sodium dodecyl sulfate (SDS) by reducing the number of bands compared to untreated samples [8]. The purpose of this study was to monitor changes in the albumin fraction of the protein of 4 sizes of peas in the raw, blanched and canned products, and the can brine solutions, using SDS-PAGE.     

Influence of dehulling on the apparent metabolisable energy and ileal amino acid digestibility of grain legumes for broilers

BACKGROUND: Removal of hulls may be an effective means of reducing the level of some antinutritional factors and improving the feeding value of grain legumes. Published data on the effects of dehulling on the energy utilisation and amino acid digestibility of grain legumes are limited. This study was designed to investigate the influence of dehulling on the nitrogen‐corrected apparent metabolisable energy (AMEn) and apparent ileal amino acid digestibility of faba beans, Australian sweet lupins and peas for broilers. RESULTS: The non‐starch polysaccharide contents of all three legume species were decreased by the removal of hulls. Dehulling increased (P < 0.05) the content and ileal digestibility of starch in faba beans but had no effect (P > 0.05) on those in peas. Dehulling increased (P < 0.05) the AMEn of faba beans and lupins but had no effect (P > 0.05) on that of peas. Removal of hulls increased the amino acid concentrations in all three legume species, but the apparent ileal digestibility coefficients of most amino acids were unaffected (P > 0.05). CONCLUSION: Dehulling of grain legumes is nutritionally beneficial in view of the improved amino acid concentrations and metabolisable energy values. Copyright © 2010 Society of Chemical Industry     

The effects of genetic variation at r,rb and Tri loci in Pisum sativum L. on apparent ileal digestibility of amino acids in young broilers

The nutritional effect of genetic variation at r and rb loci was investigated by determining apparent and true amino acid digestibility of four near‐isogenic lines of pea (RRRbRb, RRrbrb, rrRbRb, rrrbrb) fed to young broilers in a metabolism study. The results demonstrated that the round‐seeded line (RRRbRb) generally had the lowest amino acid content with, for example, 2.5 g cystine kg^?1 dry matter (DM) and 1.6 g methionine kg^?1 DM, compared with contents in the three wrinkled‐seeded lines (rrRbRb, RRrbrb and rrrbrb). The double mutant line (rrrbrb) generally had the highest amino acid content, with 3.2 g cystine kg^?1 DM and 2.3 g methionine kg^?1 DM, and an elevated amino acid content compared with the single mutant lines (RRrbrb, rrRbRb). However, the round‐seeded line (RRRbRb) consistently had the highest coefficient of true (CTID), and apparent (CAID), ileal digestibility for all amino acids (e.g. 0.959 and 0.928 respectively for CTID and CAID for methionine) when compared with the three wrinkled lines RRrbrb, rrRbRb and rrrbrb (0.853, 0.877 and 0.866, respectively, for CTID, and 0.862, 0.882 and 0.874 for CAID). A second experiment examined the digestibility of amino acids in a pair of lines, HC8 and LC8, near‐isogenic except for the locus controlling the concentration of seed trypsin inhibitor (H, high; L, low). The results showed that the CAID and CTID obtained for all amino acids were consistently higher for LC8 than for HC8 (for methionine: 0.905 and 0.709 for CTID, respectively, for LC8 and HC8; 0.887 and 0.729, respectively, for CAID), indicating the very specific effects of quantitative variation in these proteins on nutritional value of peas for poultry. Copyright © 2005 Society of Chemical Industry     

Amino acid composition of the seed albumins from chickpea

Amino acid analyses are reported for the albumin (water-soluble) fractions of embryo proteins obtained from cultivated chickpea (Cicer arietinum) and two wild forms, C. reticulatum and C. echinospermum. The sulphur amino acid contents of these fractions were 4.51, 5.50 and 5.75% respectively (molar basis). In each case, the cysteine content (2.51, 3.13 and 3.45%) was higher than the methionine content (2.00, 2.37 and 2.30% respectively). In other respects the albumin fractions from all three species were similar and represent balanced sources of all the essential amino acids except possibly tryptophane (not determined).     

Assessment of the nutritional quality of raw and extruded Pisum sativum L. var. laguna seeds

Pea (Pisum sativum L. var. Laguna) seeds were submitted to extrusion process at 129, 135 and 142 °C and modifications on the proximate composition and nutritional parameters were evaluated. Peas were a good source of protein (24 g/100 g), amino acids (sulphur amino acids were the limiting ones), dietary fibre (18 g/100 g), carbohydrates (53 g/100 g), energy (330 kcal/100 g), riboflavin and thiamine (0.1-0.2 mg/100 g). Pea seeds also contained non-nutritive compounds such as α-galactosides (4 g/100 g), phytic acid (0.4 g/100 g) and trypsin inhibitor activity (2 TIU/mg). Extrusion cooking caused a slight increase of protein and fat content, whilst it reduced dietary fibre, thiamine and α-galactosides, and led to negligible trypsin inhibitor activity (TIA) levels. The protein quality of pea measured by biological indexes (net protein utilisation, net protein ratio, relative net protein ratio, true protein digestibility and biological value) was not affected by extrusion treatments. Protein quality measured by chemical indexes (chemical score and protein digestibility corrected amino acid score) decreased in processed peas. Among extruded peas, those processed at 135 °C presented the highest chemical indexes. Therefore, the aforementioned condition could be considered adequate for the manufacture of novel pea-derived products with high nutritive value.     

Heat Induced Gelation of Pea (Pisum sativum) Mixed Globulins, Vicilin and Legumin

Mixed globulins (MG) were extracted from ground dry peas (Pisum sativum, B-160) with 0.5M NaCl, 50 mM potassium phosphate, pH 7.2, and isolated by precipitation at pH 4.5. Crude vicilin and legumin were fractionated from the MG by dialysis against 0.2M NaCl, pH 4.8, and centrifugation, then further purified using DEAE-cellulose chromatography. Conditions for maximum gel hardness of heat induced MG gel, as determined with an Instron Universal Testing Machine, were heating for 20 min at pH 7.1 at 87°C. Purified vicilin, but not legumin, formed heat induced gels. The relationship was linear between protein (globulin) concentration and log gel hardness. At all protein concentrations studied, as proportion of legumin decreased, gel hardness increased.     

THE POTENTIAL OF TERMINALIA CATAPPA (TROPICAL ALMOND) SEED AS A SOURCE OF DIETARY PROTEIN

The nutritional value of Terminalia catappa seed as a source of dietary protein was investigated. The crude protein content of the seed was high (25.81%). The amino acid analysis showed a good pattern of the essential amino acids (EAA) (in g/16 g N) - leucine (7.32), isoleucine (3.58), valine (2.74), phenylalanine (3.04), tryptophan (0.9), methionine (1.48), lysine (3.39), threonine (2.94), histidine (2.96). Tyrosine (2.12) is the limiting amino acid. The protein quality of the seed was evaluated by in vivo bioassays using weanling male Sprague Dawley rats (50–60 g). The indices of protein quality measured include PER, BV, NPU and TD. There were positive correlation between PER and BV (r = 0.7105), PER and body weight gain (r = 0.9157), PER and nitrogen intake (r = 0.7428). The results showed that T. catappa seed protein has a good pattern of the EAA, is highly digestible, can support growth and positive nitrogen balance and thus has a high dietary protein quality.     

Nutritional evaluation of high protein genotypes of pearl millet (Pennisetum americanum (L.) leeke)

Three high protein (HP) inbred lines (700112, WC-190 and B-816) of pearl millet were studied for their nutritional quality and the results compared with those of normal protein varieties. The protein content of HP lines showed an average increase of 60% but the starch and soluble sugars together and the fat content decreased by 40 and 20%, respectively. Total dietary fibre of the HP lines was about 10% higher. A decrease (about 20%) in the albumin fraction was associated with an increase in prolamin in HP lines. The amino acid composition of the HP lines remained normal except for an approximately 16% decrease in lysine. However, the total amount of lysine in the sample increased by an average of 37%, as a result of a substantial increase in protein content. True protein digestibility was very high for each line but, expectedly, the biological value was markedly lower. The values for utilisable protein were highest for high protein genotypes. Digestible energy was high in all the genotypes, although slightly lower values were obtained for the HP lines; this was attributed to the fibre fractions.