The promoting effect of electron beam irradiation on enzymatic saccharification and alcohol fermentation of sorghum meal: Related mechanisms

Abstract

In this study, sorghum meal underwent 2–10 kGy electron beam irradiation (EBI) to investigate alterations in its elemental composition, relevant physicochemical characteristics, and enzymatic hydrolysis fermentation properties. The results indicated a decrease in amylose content and an increase in reducing sugar content in sorghum meal after EBI, along with severe damage to the internal structure of starch granules, leading to increased solubility in water. Furthermore, irradiation enhanced the shear resistance and gelatinization stability of sorghum meal paste. Most importantly, EBI-induced degradation of sorghum starch molecules enhanced their susceptibility to interact with α-amylase, significantly improving the enzymatic hydrolysis and alcohol fermentation efficiency of sorghum meal. At an irradiation dose of 8 kGy, raw and cooked sorghum meal exhibited a 43.40% and 33.33% increase in ethanol concentration and a 43.44% and 30.29% increase in ethanol yield, respectively. This finding indicated that irradiation is an effective pretreatment method for starch-based ethanol fermentation.