Optimization of Dialyzed Natuphos Phytase Enzymatic Kinetics in Red Kidney Beans (Phaseolus vulgarisL)

Abstract

<abstract> <b><sc>Abstract.</sc></b> Phytate degrading enzyme (phytases) catalyze the hydrolysis of phytate (myo-inositol hexa-phosphate, IP₆) the major form of phosphorus in the plant kingdom. The degradation of phytate increases the nutrient content of the food product. The kinetics of inositol phosphate degradation by the naturally occurring endogenous phytase takes about 90 min in peas and lentil flour. Hence, the addition of purified commercial enzyme will reduced the inositol phosphate degradation time. It is therefore hypothesized that purified commercial Natuphos enzyme will increase enzyme activity and increase the inositol phosphate degradation time in whole and ground Red Kidney Beans (RKB). Thus, the objective of the study was to optimize the inositol phosphate degradation in whole and coarsely ground RKB with commercial dialyzed Natuphos enzyme. Whole and coarsely ground RKB samples were mixed in acetate buffer solution and hydrolyzed with or without dialyzed commercial Natuphos phytase enzymes. The samples were agitated in an Incu shaker at 37° C and 300 rpm. Samples were collected at 0, 6, 24, and 48 hours. The activities of the enzymes were determined at various inositol phosphate degradation times (10, 60, and 90 min). The results obtained shows the hydrolysis time (48 h) had significant effect (p<0.01) on the whole and coarsely ground RKB samples. The inositol phosphate degradation time (90 and 10 min) gave an enzyme activities of 4152 and 4045 FTU/mg, respectively and are significantly different from 60 min (3060 FTU/mg) in coarsely ground samples. The results indicate that enzymatic treatment of RKB with commercial purified phytase enzyme accelerates the breakdown of phytic acid. The results of this study will provide a system approach to improve nutritional content of legumes through bioprocessing.