Biochemical Effects of Fermentation on Selected Phytochemicals, Enzymes and Antioxidant Activities in The Under-Utilized Seeds of Chrysophyllum albidum Linn and Terminalia catappa Linn

Abstract

Chrysophyllum albidum Linn and Terminalia catappa Linn are both tropical plants. Fruits from these plants are eaten  because of their edibility and delicious taste, and the seeds being underutilized are mostly discarded. As the quest for  food security increases, food processing methods that can improve under-utilized seeds for edibility are needed. This  study’s aim was to examine the outcome of fermentation on the phytochemical and antinutrient constituents of these  seeds. Their in vitro antioxidant and enzyme activities were also studied. Tannin, phytate, alkaloid and oxalate levels  decreased significantly in the two seeds after fermentation (p<0.05). Fermented extracts from the seeds significantly  decreased (p<0.05) in their ability to scavenge 2,2-diphenyl1-picrylhydrazyl (DPPH) radical. C. albidum seeds significantly  increased (P<0.05) in ferric reducing assay property (FRAP) only, T. catappa seeds however showed a significant  decrease (P<0.05) in TAC and FRAP at the end of fermentation. A remarkable reduction (P<0.05) was detected in the  α-amylase activity of the fermented seeds of C. albidum, while a significant elevation (P<0.05) in the α-amylase activity of  the fermented T. catappa seeds manifested. Lipase activity increased significantly (P<0.05) in the fermented seeds of  both species. Significant elevation (P<0.05) of protease activity also manifested in the fermented C. albidum seeds. The distinct reduction in antinutrient status of the seeds, coupled with the increased digestive enzymes activities, was shown  during fermentation, thus indicating fermentation as a tool to enhance the edibility and health outcomes of  these under-utilized seeds.