Solid-State Fermentation Followed By Ultrasound-Assisted Extraction To Enhance Total Phenolic Level And Antioxidant Activity Of Banana Peel Extract.

Abstract

Improper disposal of agri-food wastes can have a negative impact on the environment and waste nutrition and bioactive values. In this study, solid-state fermentation (SFF) was utilized to increase total phenolic content (TPC) in the extract from banana peel, which was a common agri-food waste. After 4 days of fermentation, TPC in banana peel extract (BPE) was increased to the highest level. The optimal conditions for post SFF extraction conditions were further determined as 54/1 ml/g, 80% and 20 minutes for solvent/ solid ratio, solvent concentration and sonication time by using response surface methodology (RSM). Besides, the change of phytochemical compounds after SFF were determined. In addition, there was an undetectable level of mycotoxins in fermented BPE. Furthermore, the antioxidant capacity of fermented BPE was higher than unfermented BPE, which were evaluated by three antioxidant assays, DPPH, ABTS and FRAP. Overall, bioactive content in BPE was significantly enhanced via SFF, suggesting it as an effective approach to valorize solid wastes. These value-added products can be applicable in cosmetics, foods and pharmaceuticals.