Effects of sodium chloroacetate concentration on the physicochemical properties of carboxymethyl tapioca

Abstract

The role of reaction variables on the carboxymethylation of commercial tapioca was investigated using a statistically experimental design approach. The reaction was carried out in an isopropanol-water mixture at 25°C for 1 hr. The influence of the etherification reaction parameter on the degree of substitution (DS), moisture content, ash content, syneresis, swelling power, and solubility was determined to be the best concentration of sodium chloroacetate based on the effect on carboxymethyl tapiocas. Using FT-IR techniques allowed us to evaluate the changes in modified starch when compared to native starch. The results showed that the treatment of sodium chloroacetate concentration caused a shift in chemical properties where the values of DS (0.18-0.38), moisture content (6.65-12.96%), and ash content (0.82-1.54%) were higher than native tapioca. The syneresis of carboxymethyl tapioca (80.33-84.16%) was lower than that of native tapioca (87.91%). The new bands in Fourier transform infrared at 1597-1604 cm-1 and 1450 cm-1 indicated that the starch granules were substituted. The concentration of sodium chloroacetate caused an increase in the swelling power of carboxymethyl tapioca (0.19- 2.45 g/g) and an increase in solubility (58.91-74.44%). The best concentration of sodium chloroacetate was 20%, which produced carboxymethyl tapioca with a DS of 0.38; a moisture content of 6.65%; an ash content of 1.17%; a syneresis of 80.33%; a swelling power of 2.45 g/g; and a solubility of 74.44%. The correlation analysis showed that very close relationship (R2 > 0.8). Generally, carboxymethyl tapioca has changed its chemical and physical properties.