FAT CONTENT PREDICTION AND FISH GELATINE MODIFICATION IN YOGURT SYSTEM

Abstract

In this thesis, the rheological properties of yogurt products with milk fat reduction and replacement are evaluated to predict and improve the quality of yogurt products. First, a PSO-BP-ANN model was implemented to achieve a quick prediction of fat content in yogurt based on the flow properties. The model was proved to be accurate with MSE and R2 of 0.0042 and 0.9921, which can be potentially applied in the yogurt industrial production. Afterward, fish gelatin (FG) was modified by xanthan gum (XG) and applied in acid milk gels and low-fat yogurts to mimic the rheology and texture properties of porcine gelatin (PG). We found that milk gels with an XG to FG ratio of 1:99 best mimicked the storage moduli of milk gels with PG. Moreover, yogurt with XG-modified FG had better water-holding capacity and consistency than yogurt with PG, yet similar in viscosity, pseudoplasticity, and thixotropy.