Effect of enzymatic (thermostable α-amylase) treatment on the physicochemical and antioxidant properties of extruded rice incorporated with soybean flour. (15th April 2016)

• Record Type: Journal Article
• Authors: Xu, Enbo; Wu, Zhengzong; Pan, Xiaowei; Long, Jie; Wang, Fang; Xu, Xueming; Jin, Zhengyu; Jiao, Aiquan
• Is Part Of: Food chemistry. Volume 197:Part A(2016)
• Page Start: 114
• Page End: 123
• Publication Date: 2016-04-15
• Subjects: Rice/soybean mixture -- Enzymatic extrusion -- Physiochemical property -- Antioxidant property; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2015.10.109
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: The enzyme increased BD and WSI, while decreased WAI and viscosity of R/S mixture. Antioxidant activity was improved by the combined addition of soybean and enzyme. The highest TPC/TFC retention was achieved with soybean added up to 30%. Abstract: In order to determine the effect of enzymatic extrusion on the physicochemical and antioxidant properties of rice/soybean mixture, different mass ratios (100/0, 95/5, 85/15, 70/30, 50/50 and 25/75%, w/w) were treated with thermostable α-amylase. The reduced special mechanical energy and the enhanced product temperature were closely and regularly linked with the increase of soybean content. The bulk density and water solubility index increased, and the water absorption index and viscosities decreased remarkably after enzymatic extrusion, however, the modification caused by α-amylase were dramatically eliminated with the increase of soybean content to ∼50%. Moreover, the addition of enzyme exhibited an improvement of the total phenolic/flavonoid content (TPC/TFC) and antioxidant capacities compared to traditional extrusion. The TPC/TFC retention of extrudate (ratios of 85/15 and 70/30%) attained over 90%, but dramatically decreased (72.91 and 67.81%, respectively) with soybean added to 75%, probably due to the great reduction of starch substrate for enzymatic hydrolysis.