Impact of Thermal and Thermosonication Blanching on Peroxidase Inactivation, Microbial Stability, Sensory Quality, and Microstructural Alterations of Sugarcane Billets

ABSTRACT Since sugarcane juice is a highly perishable commodity, its quality rapidly deteriorates upon extraction due mostly to microbial growth and peroxidases (PODs) catalytic activity. These factors are together present significant obstacles to the large scale commercialization of sugarcane juice. This study aims to evaluate the effect of thermal (TB) and thermosonication blanching (SB) of sugarcane billets (a standard‐sized piece of sugarcane stalk) on inactivation kinetics of POD enzyme, total plate count (TPC) and sensory attributes of sugarcane juice at different temperature ranges of 70°C–90°C for 3, 6, 9, 12, 15 and 18 min. The two‐fraction model showed the best fit of the inactivation kinetics data of POD enzyme in both the blanching methods. The substantial potency of the SB treatment was found to be apparent, as the residual activity substantially declined below 20% at 90°C for 15 min. The D ‐value for the labile POD fraction in TB and SB at 90°C was 18.88 and 15.83 min, respectively. The POD activity in SB had activation energy ( E a ) of 29.41 and 23.37 kJ mol −1 for labile and stable fractions, respectively. A 9‐point hedonic rating of SB sample at 90°C for 12 min retained most of the sensory attributes and quantitative descriptive analysis (QDA) showed a close resemblance with fresh sugarcane juice. The SEM analysis revealed that the thermosonication exerts a more aggressive effect on the sugarcane microstructure compared to thermal blanching. The optimum and acceptable combination determined was 90°C for 12 min on SB, with the 5.0 log cycle reduction in bacterial count.