Solid-state fermentation using wheat bran to produce glucose syrup and functional cereal bars

Abstract

Wheat bran is one of the most abundant by-products from grain milling, which can be applied as substrate for solid-state fermentation to obtain enzymes able to convert this agro-industrial residue into glucose syrup, which in turn can be used for the production of different food products. Present study aimed to determine centesimal composition of wheat bran, obtain enzymatic extract that converts wheat bran into wheat glucose syrup, produce rice flakes cereal bars using glucose syrup, and evaluate their nutritional composition and the presence of functional compounds, as well as their antioxidant potential. Cereal bars were evaluated to determine reducing sugars, soluble proteins, and total polyphenols and flavonoids content. Antioxidant evaluation and enzymatic extract obtained presented amylolytic activity and it was able to produce cereal bar. Produced with wheat glucose syrup proved to be a source of dietary fiber (1.8 g) and soluble protein (7.2 g) while the rice flakes produced with corn glucose syrup did not present these nutritional components. Cereal bar produced with glucose syrup presented phenolic compounds, among them flavonoids. In addition, they exhibited antioxidant activity by radical scavenging (47.46%), reduced ion iron (71.70 µM Trolox equivalent/g) and radical stabilization (711.89 µM Trolox Equivalent/g). Final product maintained organoleptic profile characteristic of cereal bars and it showed a decrease in caloric value and sodium content. Therefore, the present study showed that the bioprocess yields a nutritional, ecological, and functional food product, which might be of great interest for food industry, adding nutritional and functional value to a well-stablished product.