Enzymatic Pretreatment of Waste Bread for Glucose Syrup Production

Abstract

One of the pre-treatments developed to separate monosaccharide from starch polymerization is enzymatic hydrolysis. Leftover bread is abundant in bakeries and homes, and this waste can cause the build-up of carbon dioxide in the atmosphere. According to this study, due to their high carbohydrate content, expired bread can be used as a source of glucose or a substrate for various industrial processes, including ethanol and organic acids. The expired bread was heated for 15 minutes before the gelatinization process, followed by the liquefaction and saccharification processes. The liquefaction process uses different temperatures (30, 40, 50, 60, 70) ℃, enzyme concentrations (2, 4, 6) g, and reaction times (0, 60, 90, 120, 180, 240) min. Different temperatures (50, 60, 70, 80) ℃ and reaction times (30, 60, 90, 120) min were applied for the saccharification process. ATR-FTIR was used to identify the functional group present in the sugar, and a UV Spectrophotometer was used to analyze sugar concentrations. The highest concentration of glucose yield during the liquefaction process was found to be at 50 °C, 6 g, and 180 min of optimization condition. The highest glucose concentrations were found at 60 °C after 60 min for the saccharification process. The optimization of hydrolysis pre-treatment improves the yield of glucose syrup from the waste bread.