Produção de açúcares redutores por hidrólise ácida e enzimática de farinha de arroz

Abstract

The use of modified starches in food has been an viable alternative to improve the characteristics of the native starches can not confer. The broken rice is a raw material produced in large quantities in the country, obtained by the fraction of broken grains generated during the processing of grain, and has high starch content. The objective of this study was to evaluate the effect of acid and enzymatic hydrolysis in broken rice flour, aiming at the production of reducing sugars and add value to by-product of rice industry. The rice flour which showed 0.38g.100g -1 ash, 8.33g.100g -1 protein, 90.19g.100g -1 carbohydrate and 1.10 g.100g -1 lipids were subjected to hydrolysis acid with HCl, 1:5 (w/v) in concentrations 0.075, 0.15 and 0.30M in a water bath under stirring at 50 ° C. Also enzymatic hydrolysis was performed in the same proportion of flour, 1, 2 and 3U of α-amylase, sodium acetate buffer 0.025M, in a water bath under stirring at 40 ° C. There was a greater production of reducing sugars in the concentration 0.30 M HCl at 50 ° C and 9h of acid hydrolysis (2.25 mg.g -1 flour) and hydrolysis with α- amylase-flour with 2U.g flour- 1 obtaining a 46.60 mg.g flour -1 , 2h. Acid hydrolysis showed low values as the production of reducing sugars, as was performed under mild conditions of temperature and weak concentrations of HCl, but the enzymatic hydrolysis is efficient and can be easily employed in the modification of rice flour for the generation of new ingredients for the food industry.