Nutritional Evaluation of Processed Kawal (Cassia obtusifolia) as Influenced by Origin and Residual Antinutritional Factors

Abstract

Kawal (Sicklepod) samples of different origin are used in this study. The study was conducted to investigate the effect of residual antinutritional factors on protein and minerals availability, protein fractions and amino acid composition. Two raw samples were collected from Algenina and Zalnge and two processed ones from Algenina and Omdurman were used in this study. The proximate composition varied between the samples. Processing (fermentation and cooking) of the samples caused an increase in some parameters and decrease in others. The protein fractions fluctuated, and the rate of change depended on the sample origin and type of processing method. The antinutritional factors of the samples were significantly (P ≤ 0.05) decreased after fermentation and cooking, but the rate of reduction differed between the samples. The reduction in antinuritional factors was concomitant with an increase in protein digestibility. Total major minerals were significantly (P ≤ 0.05) increased after processing (fermentation and cooking) but the trace ones fluctuated. However, minerals extractability of both significantly (P ≤ 0.05) increased. Fermentation of Algenina sample increased glysine, alanine, valine, cystine, leucine, isoleucine, phenylalanine and ammonia content but decreased aspartic, threonine, serine, glutamic, tyrosine, histidine, lysine and arginine contents. The first limiting amino acid of fermented Algenina sample was lysine with a score value of 73.9. Cooking of Omdurman v fermented sample had no significant effect on all amino acids except phenylalanine which is decreased, whereas cooking of fermented Algenina had no significant effect on most amino acids except aspartic, threonine, serine, glysine and phenylalanine which is decreased while it is increased ammonia content of both samples. Although cooking increased the lysine score of both fermented samples it still the first limiting amino acid. The second limiting amino acid of Omdurman cooked sample was sulphur amino acids (90.3%).