The Effect of Water Sorption and Glass Transition Temperature on Non-Enzymatic Browning Reaction of Food Models

Abstract

This research was aimer/ to study the extend of non enzymatic browning reaction in food models containing the mixture of tapioca starch, casein, sucrose and oh at different moisture contents (2.55%, 5.26%, 7.54%, 15.20%. 15.93% and 23.99%) and storage temperatures (30, 55 and 70⁰C). The non-enzymatic browning reaction was detected from brown color intensity measured by spechtrophotometer and colorimetric methods. The non-enzymatic browning reaction or food model follow pseudo-zero order reaction, suggesting that browning reaction occurred at moisture content above monolayer zone. T-Tg (T storage - Tg prediction) and reaction rate constant (k) plots showed that browning reaction occurred at temperature around glass transition and increased significantly at 15⁰ above Tg of casein. Tapioca starch in the food model was under glassy condition. The mobility of substrate increased and diffused at amorphous matrix.

Keywords : glass transition, non-enzymatic browning, glassy, amorphous