UHT-STERILIZED PEANUT BEVERAGES - KINETICS OF PHYSICOCHEMICAL CHANGESDURING STORAGE AND SHELF-LIFE PREDICTION MODELING

Strawberry-flavored (S04) and chocolate-flavored (C04 and C20) peanut beverages UHT-sterilized (137 degrees C, 4 sec or 20 sec) and aseptica lly filled in Tetra Briks were stored for 6 mo at 5, 20 and 35 degrees C. Sensory characteristics and kinetics of physicochemical changes we re studied. The changes were of zero (pH of S04, and sedimentation and homogenization indices of all beverages) and first (pH of C04 and C20 , viscosity and color lightness of all beverages) order. Reaction rate constant and Gibb's free energy increased with temperature. Activatio n energy followed Arrhenius equation. Deterioration in beverage sensor y qualities highly correlated with increase in sedimentation index and decrease in pH and emulsion stability. Shelf-life prediction models w ere constructed based on sensory and kinetics data. The shelf-life was estimated to be 4-7 mo for beverages stored at 30-35 degrees C.