Amido de milho modificado com ácido lático: avaliação das propriedades físico-químicas

Abstract

This study aimed to develop a new technique of esterification of corn starch with lactic acid, an acid commonly found in nature, and analyze their functional properties. For esterification of starch was used lactic acid (2,5% w/w) and heating at 150 °C by time interval of 0-7 hours. For evaluation and certification of the actual chemical modification after treatment, ie production of a starch lactilado analysis was performed to quantify the percentage of formation of lactyl in all samples during the heating times were (0.5 to 7.0 hour), dextrinization degree, solubility, amylose, intrinsic viscosity, viscosity, clarity paste. Through the results of the physicochemical analysis can be seen that the treatment was effective for forming high percentage of lactyl 0.94 to 3.85%, with increasing treatment time is observed increase in dextrose equivalent (DE) ranging from 0.38 to 1.88, solubility increased with increasing treatment time of 2.26 to 34.21% transmittance another index was increased compared to native starch 1.8% in reading with the lowest transmittance to 82.1%. In the analysis of transmittance can also observe that with 3 hours and can produce starch esterified with resistance retogradação on condition of cold storage on analysis of the percentage of amylose was reinforced the idea that the treatment was effective, since resulted in a significant decrease 22.36 of the acidified starch to heat treatment without the starch 12.58% with 7.0 hours of thermal treatment, the intrinsic viscosity fell from 1.09 to 0.07, indicating a high breakdown of glycosidic linkages, the apparent viscosity also Got fall in the three reading cycle whilst in native starches and sour and dry was not possible to determine the viscosity grade for being off-limits maximum viscosity of the device.