Comparative effect of germination time on trypsin inhibitor concentration in soya bean under aeroponic fodder production conditions

Abstract

Soya bean is a relatively inexpensive protein source, can be grown and accessed by small scale farmers for use as livestock feed, its utilization is limited by presence of trypsin inhibitors (TIs) which impair protein digestion. Germination being a recommended non-thermal method to reduce/ eliminate trypsin inhibitors in soya bean, this study evaluated effects of germination time on trypsin inhibitors in Maksoy 3N and Maksoy 6N over 7 days using a factorial completely randomized design. Results showed a significant effect of germination time on TI reduction (p = 0.002), with levels decreasing from 0.365 TUI/mg (0.000365 mg/g) for Maksoy 3N and 0.513 TUI/mg (0.000513 mg/g) for Maksoy 6N on day 1 to 0.101 TUI/mg (0.000101 mg/g) (72% reduction) and 0.033 TUI/mg (0.000033 mg/g) (94% reduction) respectively by day 7. The study further showed that Maksoy 6N has a slightly faster and greater reduction in inhibitors indicating genetic variability of different genotypes to the treatment process. This study confirms that germination under aeroponic conditions is an effective and reliable non-thermal method for reducing trypsin inhibitors in soya bean where after day five, farmers, nutritionists and feed producing companies can harvest soybean sprouts as they are safer and beneficial for livestock performance.