Evaluation of the Protein Quality and Available Lysine of Germinated and Fermented Cereals

Abstract

Germinated wheat and barley increased significantly (P < 0.05) in % Relative Nutritive Value (RNV); the increase in % RNV was highly significant (P < 0.01) for germinated rice. The increase in available lybine was highly significant (P < 0.01) in germinated wheat, barley, oats and rice. Natural lactic acid fermentation increased the % RNV significantly (P < 0.05) for wheat, barley and rice and significantly (P < 0.01) for millet and maize. The available lysine content increased significantly (P < 0.05) in fermented oats, rice, millet, and maize but the available lysine increase was highly (P < 0.01) signiticant in fermented wheat. Both germination and fermentation had equivalent effects as procedures to improve the protein quality of cereals.

Germination: a means to improve the functionality of oat

“…Dalby and Tsai (1976) and Wu (1983) observed an increase in albumin content (rich in essential amino acids, lysine and tryptophane) during oat germination, and a subsequent decrease in globulin and prolamine contents (poor in lysine) leading to increased nutritional value of germinated oat. Hamad and Fields (1979) also found an increase in lysine content during germination, but the calculations did not show any significant increase in the nutritional value of oat when compared to casein. Shutov and Vaintraub (1987) have proposed that globulins undergo changes in their solubility at the beginning of germination, making them more susceptible for seed endoproteinases.…”

“…The nutritional value of oat proteins is higher than that of other cereal proteins due to lower content of prolamine protein (Peterson 1976, Hamad andFields 1979). The total protein content of oat increases slightly during germination due to more intensive degradation of other kernel components for respiration (Dalby and Tsai 1976).…”

Fermentation and germination improve nutritional value of cereals and legumes through activation of endogenous enzymes

“…While increase in protein may partly be attributed to loss of dry matter during fermentation, bacterial fermentation is known to increase lysine content in fermented grains (Hamad & Fields, 1979). Bacterial fermentation produced lysine and increased its concentration by many folds and made cereal protein complete (Hamad & Fields, 1979). This increase may partly be due to degradation of complex protein by microorganism thereby releasing peptides and amino acids (Pranoto et al., 2013).…”

Les Aspects Technologiques, Microbiologiques Et Nutritionnels Des Aliments Fermentes a Base De Lait Et De Mil en Afrique De L’ouest.

“…L'impact de la fermentation sur la teneur en protéines des céréales et la qualité des acides aminés a fait l'objet de nombreux travaux antérieurs. La fermentation du mil conduit à une augmentation de la teneur en lysine (Hamad,Fields, 1979). De même une augmentation de la teneur en méthionine et de celle de la tryptophane ont été observées au cours de la fermentation du maïs (Nanson,Fields, 1984 (Khetarpaul,Chauhan, 1990).…”