Seed Protein Quality Research Articles

Germination alters the chemical composition and protein quality of lupin seeds

AbstractThe chemical composition and protein quality of the kernels from Lupinus angustifolius seeds were compared with that for sprouts after 6 days germination. Germination resulted in an apparent increase in protein content from 395 g kg−1 to 435 g kg−1 DM. Fat and carbohydrate contents decreased. The oligosaccharide content of the sprouted lupin fell to a negligible level, while the phytate and alkaloid concentrations fell from 4.7 g kg−1 to 1.6 g kg−1 and from 0.72 g kg−1 to 0.16 g kg−1, respectively.The quality of lupin kernel protein was poor with a protein efficiency ratio (PER) of 1.45±0.15. Supplementation of kernel with DL‐methionine (2.0 g kg−1) increased the protein quality (PER = 2.87±0.17) to that of casein (PER = 2.86±0.18). Germination reduced protein quality (PER = 0.44±0.16), and did not improve apparent protein digestibility (APD kernel = 80.4%; APD sprout = 77.5%). Supplementation of sprout protein with DL‐methionine (2.0 g kg−1) increased the protein quality (PER = 2.57±0.20). The total sulphur‐containing amino acid concentration of lupin kernel protein, 1.9 g per 16 g N was low, and decreased further to 1.3 g per 16 g N in the sprout, a drop of 32%.The results showed that germination of lupin seeds reduced the concentration of the anti‐nutritive factors; however, it also reduced protein quality.

Anatomy and composition ofZostera MarinaL.: A potential new crop

Chemical composition of Zostera marina L. seed and shoots was determined. Morphology and histochemistry of mature seeds were studied by fluorescence, brightfield and scanning electron microscopy to locate storage constituents in the seed. Starch content in the mature seed was 51% and was the major storage reserve in the embryo and a minor component in the testa. Starch in the shoots ranged from 0.3 to 2.3%. Protein, located in the embryo as small protein bodies, comprised about 9.0% of the seed. Protein in shoots ranged from 6–15%. Protein quality of both seeds and shoots resembled corn in composition, and the first limiting amino acid was lysine. Shoots were high in minerals, fiber and ash, while seeds were lower in these constituents. Fat was low (0.3–1.7%) in both shoots and seeds.

An evaluation of protein quality of fenugreek seeds ( Trigonella foenumgraecum) and their supplementary effects

The chemical composition and the nutritional value of protein of whole as well as solvent-extracted fenugreek seeds were determined. Fenugreek seeds are rich in protein (25·5%), fat (7·9%), unavailable carbohydrate (48%), mucilaginous matter (20%) and saponins (4·8%). The replacement of casein diet up to 10% by fenugreek seeds (extracted) did not produce any deleterious effect on protein quality of casein as assessed by protein efficiency ratio (PER), protein and dry matter digestibilities and net protein utilization (NPU). Further increasing the level of fenugreek did reduce these parameters. The extraction of seeds improved, and cooking did not alter the quality of fenugreek seed protein.

Effect of Roasting on the Chemical Composition and Protein Quality of Lupin Seeds (Lupinus albus cv Multolupa)

ABSTRACTThe effect of roasting lupin seeds (Lupinus albus cv Multolupa) for 10, 20, 30, and 40 min at 80–90°C was studied. Raw lupin was shown to be markedly deficient in the S‐amino acids. These were not affected by roasting for 10 min, although a mild loss was observed for isoleucine and valine. However, heating for up to 40 min caused important losses in lysine and methionine + cystine. PER for raw lupin was 0.80 (casein 2.93) and that of the 10 min heated sample was 0.92 (NS), while roasting for 20, 30 and 40 min caused a severe reduction in protein quality (PER 0.59, 0.53 and 0.46 respectively). All these values improved significantly (p<0.01) by supplementation with 0.1% DL‐methionine. Heating lupin seeds for 10 min may help to remove the “beany” flavor of this legume.

Role of lipoxygenases in soybean seed protein quality

Role of lipoxygenases in soybean seed protein quality

Maintenance of Normal or Supranormal Protein Accumulation in Developing Ovules of Glycine max L. Merr. during PEG-Induced Water Stress

Protein accumulation in developing ovules of hydroponically grown soybean (Glycine max L. Merr.) plants was unaffected or enhanced by polyethylene glycol-induced water stress. The cultivar Wayne and the experimental variety ;9656' were severely stressed by inclusion of PEG-6000 in the nutrient solution to water potentials as low as -20 bar. Leaves rapidly yellowed and abscised under these conditions. Fresh and dry weight of ;Wayne' ovules was reduced by severe stress, but protein content was unaffected. Ovules of 9656 were more resistant to severe stress: fresh weight and dry weight were unaffected by stress and protein content increased. Moderately stressed Wayne ovules behaved like severely stressed 9656 ovules: seed fresh weight and dry weight were unaffected and protein content increased. However, protein content did not increase if the plants were defoliated. No changes in seed protein quality were observed with stress, based on polypeptide banding patterns after one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

Effect of preparation and cooking on the nutritive value of local kidney bean

Nutritive value and protein quality of kidney bean before and after different methods of preparation and cooking had been studied. This was done to find out whether the nutritive value and protein quality of kidney bean seeds are affected by soaking them before boiling or not. Kidney bean seeds (var. Giza 3) were either boiled or soaked and then boiled. Moisture, crude protein, fat, Carbohydrate, ash, fiber, caloric value and some minerals including Calcium phosphorus and iron were determined in both raw and prepared seeds. Evaluation of the protein quality was done by determining the protein efficiency ratio, net protein ratio and serum analysis of rats fed diets containing either raw or prepared seeds. Serum analysis included the estimation of total serum proteins, albumin/globulin ratio and free non essential to essential amino acids ratio. The results showed that kidney bean is rich in carbohydrate and protein, poor source of dietary calcium and reasonably good source of dietary iron. It was also clear that although seeds, boiled without soaking contained higher percentages of minerals than those boiled after soaking, yet, they were lower in protein quality. This was proved by the results of all the methods used for protein quality evaluation.

Genetic control of seed proteins in wheat

Electrophoretic profiles of crude protein extracts from seed of F1 hybrids and reciprocal crosses among diploid, tetraploid and hexaploid wheats were compared with those of their respective parental species. The electrophoretic patterns within each of three pairs of reciprocal crosses, T.boeoticum X T.urartu, T.monococcun X T. urartu and T.dicoccum X T. araraticum, were different from one another but were identical with those of their respective maternal parents. Protein bands characteristic of the paternal parents were missing in F1 hybrid seed suggesting that the major seed proteins in wheat were presumably regulated by genotype of the maternal parent rather than by the seed genotype. However, in another three pairs of reciprocal crosses, T.boeoticum X T. durum, T.dicoccum X T.aestivum and T. zhukovskyi x T. aestivum, protein bands attributable to the paternal parents were present in the F1 hybrid seeds indicating that the seed proteins were not always exclusively regulated by the maternal genotype. The expression of paternal genomes is presumably determined by dosage and genetic affinity of the maternal and paternal genomes in the hybrid endosperm. The maternal regulation of seed protein content is probably accomplished through the maternal control over seed size. The seed protein quality may, however, depend upon the extent of expression of the paternal genome.

Nitrogen Metabolism in Soybean Tissue Culture

Cultured soybean (Glycine max, Kanrich variety) cells grow with 25 mm urea as the sole nitrogen source but at a slower rate than with the Murashige and Skoog (MS) (Physiol. Plant. 15: 473-497, 1962) nitrogen source of 18.8 mm KNO(3) and 20.6 mm NH(4)NO(3). Growth with urea is restricted by 18.8 mm NO(3) (-), 50 mm methylammonia, 10 mm citrate or 100 mum hydroxyurea, substances which are much less restrictive or nonrestrictive in the presence of ammonia nitrogen source. The restrictive conditions of urea assimilation were examined as possible bases for selection schemes to recover urease-overproducing mutants. Since urease has higher methionine levels than the soybean seed proteins among which it is found, such selections may be a model for improving seed protein quality by plant cell culture techniques.Callus will not grow with 1 mm urea plus 18.8 mm KNO(3). Urease levels decrease 80% within two divisions after transfer from MS nitrogen source to 1 mm urea plus 18.8 mm KNO(3). Hydroxyurea is a potent inhibitor of soybean urease and this appears to be the basis for its inhibition of urea utilization by callus cells.Stationary phase suspension cultures grown with MS nitrogen source exhibit trace or zero urease levels. Soon after transfer to fresh medium (24 hours after escape from lag), urease levels increase in the presence of both MS or urea nitrogen source. However, the increase is 10 to 20 times greater in the presence of urea. NH(4)Cl (50 mm) lowers urease induction by 50% whereas 50 mm methylammonium chloride results in more drastic reductions in urea-stimulated urease levels. Citrate (10 mm) completely blocks urease synthesis in the presence of urea.Ammonia and methylammonia do not inhibit soybean urease nor do they appreciably inhibit urea uptake by suspension cultures. It appears likely that methylammonia inhibits urea utilization in cultured soybean cells primarily due to its "repressive" effect on urease synthesis.Citrate does not inhibit urease activity in vitro and exhibits only a partial inhibition (0-50% in several experiments) of urea uptake. It appears likely that the citrate elimination of urease production by cultured soybean cells is due to its chelation of trace Ni(2+) in the growth medium. Dixon et al. (J. Am. Chem. Soc. 97: 4131-4133, 1975) have reported that jack bean (Canavalia ensiformis) urease contains nickel at the active site.

Genetic and Environmental Variation of Seed Yield, Yield Components, and Seed Protein Quantity and Quality of Cowpea1

Pure line cultivars of cowpea (Vigna unguiculata (L.) Walp.) were grown in the field at Ile‐Ife, Nigeria, and the biotron and greenhouse at Madison, Wis., in both short‐ and long‐day environments to study yield, yield components, percent protein, and amino acid content of the mature seeds. Seeds/pod, 50‐seed wt, and methionine content demonstrated medium to high broad sense heritability and the other traits were medium to low. Genotypic variance components for 50‐seed wt, seeds/pod, percent protein, mg of methionine/g of flour and g of methionine/l00g of protein, and genotype ✕ location components for 50‐seed wt and percent protein were statistically significant and large enough to be of practical importance. Genotypic and phenotypic correlations of yield with 50‐seed wt were high and positive, whereas those for yield with percent protein, yield with methionine content, and 50‐seed wt with tryptophan content were negative and relatively high. ‘Producer,’ which is high in percent protein and yield, is a promising parent in crosses with Nigerian local cultivars