engleski

Properties of starch roasted with apple distillery wastewater

The use of chemicals in the food industry raises concerns among an increasing number of consumers. The application of organic acids, occurring naturally in plant materials, for starch esterification may represent an alternative to the methods for its chemical modification. This study is aimed at producing starch esters by roasting potato starch with apple distillery wastewater at various temperatures and to determine the effects of esterification conditions on the selected properties of the modified preparations. Apple distillery wastewater was concentrated, mixed with starch (30 g of dry matter per 100 g of starch), dried, and roasted at temperatures of 110, 130, or 150 °C for 3 hours. The resultant preparations were rinsed 30 times with a 60% ethanol solution, dried, and disintegrated. After that, the following analyses were performed: the content of substituted acids (after base de-esterification) with liquid chromatography (HPLC) ; pasting parameters based on DSC thermal characteristics ; swelling power and solubility in water at the temperature of 80 °C ; colour changes with a colorimeter ; rheology of the pastes based on plotted flow curves ; and the resistance of pastes to amyloglucosidase. Starch esterification was effective at the temperatures of 130 and 150 °C, and in these cases starch was esterified with malic, citric, formic, and maleic acids. Roasting at 110 °C only caused negligible esterification with malic acid. Starch treatment with apple distillery wastewater at 130 and 150 °C caused changes in its properties compared to the control samples, including: lower temperature and heat of pasting, lower swelling power and solubility in water, darker colour, higher resistance to amyloglucosidase, and formation of pastes with lower viscosity.

starch ; esterification ; apple distillery wastewater

nije evidentirano