Effect of thermosonication batch treatment on enzyme inactivation kinetics and other quality parameters of cloudy apple juice

• Published in: Innovative food science & emerging technologies 2018-06, Vol.47, p.71-80
• Main Authors: Illera, A.E., Sanz, M.T., Benito-Román, O., Varona, S., Beltrán, S., Melgosa, R., Solaesa, A.G.
• Format: Article
• Language: English
• Subjects: Cloudy apple juice; Dissolved gases; Enzyme inactivation; Thermosonication
• ISSN: 1466-8564; 1878-5522
• DOI: 10.1016/j.ifset.2018.02.001

Cloudy apple juice has been treated by thermosonication in batch mode as an alternative processing to thermal treatment. Thermosonication was found to be effective to inactivate polyphenol oxidase; however, pectinmethylesterase was found to be more resistant. An increase of the working ultrasound amplitude and the amount of energy supplied to the juice led to lower enzyme residual activities. Enzyme inactivation kinetics were determined at different temperatures (from 44 to 67 °C). Inactivation data were described by the first order kinetic model and the Weibull model, both models yielding good fitting. Thermosonication treatment caused a homogenization effect reflected in the shifting of the particle size distribution towards smaller diameters. The effect of the nature of dissolved gases in the juice on enzyme inactivation was studied by displacing the air dissolved in the juice by bubbling nitrogen or carbon dioxide, previous to the thermosonication experiments. Higher inactivation rates were obtained by displacing the air with nitrogen. Consumers demand of natural and fresh-like products has driven the food industry to investigate alternative technologies to replace conventional food heat treatments that may affect food quality. Among these technologies, thermosonication treatment is an attractive technology that can inactivate microorganisms and enzymes. This work shows that some enzymes that cause deleterious effect on cloudy apple juice can be more effectively inactivated by thermosonication than by thermal treatment, in the same temperature range, reducing the damages caused by heating. •Enzyme inactivation increased with amplitude, power density and temperature.•TS treatment decreased particle size of cloudy apple juice.•PME was more TS resistant than PPO.•Faster enzyme inactivation kinetics in the presence of nitrogen were observed.•After TS color change was noticeable and TPCs increased.