Evaluation of Protein Nutritional Quality of Four Soybean Varieties Grown in Western Kenya

Abstract

Protein nutrition is important for human health because its deficiency leads to major public health problems such as Protein Energy Malnutrition. Soybean an excellent and cheap source of high quality protein has been introduced into the Western Kenya and other developing countries for improved health and food security, but end use qualities may reduce its utilization. The main objective of this study was to evaluate the protein nutritional quality of four soybean varieties grown in Western Kenya. Protein quality was determined using male weanling albino rats for the indices of net protein retention, food efficiency, apparent and true protein digestibilities and faecal weight. Soybean amino acid efficiency was evaluated using Protein digestibility corrected amino acid score (PDCAAS). Soybean diet SB 132 had the highest protein nutritional quality with the best protein retention of 6.29 g, Apparent Protein digestibility of 89.13%, True Protein Digestibility of 96.48%, weight gain of 5.50 g and a Net Protein Retention Ratio of 4.70. All the four soybean varieties had high amino acid profiles with a Protein digestibility Corrected Amino Acid Score of 1.0. Soybean variety SB 132 is the most superior in digestibility and the study recommends its promotion as a food crop in Western Kenya and other developing countries for the management of Protein Energy Malnutrition and for food security.

Protein quality of soy and the effect of processing: A quantitative review

“…They reported PDCAAS values of 54 and 64 for two different soybean cultivars after dry heating, which are lower compared to the mean value of 82.2 for untreated soybean obtained by Stone et al ( 23 ). In contrast, boiling soybeans (100 °C) was found to increase PDCAAS values to scores of approximately 100 ( 24 ). Additional autoclaving of soybean meal to 121 °C did not have a profound effect on the PDCAAS value ( 8 , 21 ).…”

Efficacy of compositing with snail meat powder on protein nutritional quality of sorghum–wheat buns using a rat bioassay

“…On the other hand, a reduced food and protein intake of the rats fed the basal diet might have resulted from a deficiency of some indispensable amino acids, minerals, and vitamins in the diet that led to an imbalance in nutrients . Earlier, Agengo et al . established that the type and quantity of protein in diet influences the amount of food consumed.…”

“…also demonstrated that rats fed on a sorghum biscuit diet produced between 52% and 62% higher faecal bulk than rats fed respectively on a casein and a sorghum–soy composite biscuit diet. It may be postulated that a high faecal bulk is attributed to a large amount of unabsorbed residue in the diet, which elicits increased faecal excretion . Rats fed on S‐WBs diets fortified with SMP produced comparable faecal weights, but these were significantly lower than those fed on an unfortified S‐WB diet (Table ).…”

Effect of cooking on the in vitro and in vivo protein quality of soy, oat and wheat varieties

“…Navarro oat is the only thermally treated protein to demonstrate a significantly lower TPD (88.79%) relative to both cooked varieties of soy and wheat (92.7% and 92.36% on average respectively). Previously, four varieties of soy subject to soaking and boiling produced a range of similarly high TPD (92.12% −96.48%) (Agengo et al, 2018) 1979) relative to the wheat prepared in this study, but were more similar in TPD for wheat cereal (91%) and whole wheat bread (92%) (Sarwar, 1987). Rolled oats-if prepared similarly to traditional methods (Decker et al, 2014)-may increase TPD relative to raw oats (91.0%−92.6%) (Eggum et al, 1989;Mcdonough et al, 1990;Sarwar et al, 1989) and increase further when prepared as a porridge (95.2%) (Rutherfurd et al, 2015).…”