The improvement of nutrition quality, antioxidant capacity, and functional properties of cowpea (Vigna unguiculata) sprout flour through NaCl and Naalginate elicitation

Abstract

Cowpea exhibits potential antioxidant capacity, and various health benefits, as well as a good source of protein and nutraceutical compounds. Our previous study showed that elicitation using 50 mM NaCl or 250 ppm Na-alginate before germination is the most effective technique to improve the antioxidant capacity of cowpea sprout with the lowest impact on the reduction of germination power and yield. The objective of this research was to evaluate the potential of NaCl and Na-alginate elicitation on the improvement of the nutrition quality (proximate), antioxidant capacity (total phenolic content, total flavonoid content, reducing power, and Trolox equivalent antioxidant capacity (TEAC)), and functional properties (water absorption capacity (WAC), oil absorption capacity (OAC), water holding capacity (WHC), oil holding capacity (OHC) and emulsion stability (ES)) of cowpea sprout flour. The cowpea sprout was prepared with and without elicitation (control) by immersing the cowpea seeds either in 50 mM NaCl, 250 ppm Na-alginate or distillate water for 8 hrs prior to germination for 48 hrs. The sprouts then were dried, milled, and sieved to produce sprout flour. The research results proved that elicitation significantly increases the protein and total mineral levels, functional properties, and antioxidant capacity, and reduces the fat and carbohydrate levels of cowpea sprout flour. Elicitation using Na-alginate produced a higher improvement of OHC, nutrition, and antioxidant capacity of elicited cowpea sprout flour than that of NaCl elicitation. This study provides an alternative strategy for improving the nutrition, antioxidant capacity, and functional properties of legume flour.