Effect of high hydrostatic pressure on overall quality parameters of watermelon juice

Abstract

High hydrostatic pressure as a kind of non-thermal processing might maintain the quality of thermo-sensitive watermelon juice. So, the effect of high hydrostatic pressure treatment on enzymes and quality of watermelon juice was investigated. After high hydrostatic pressure treatment, the activities of polyphenol oxidase, peroxidase, and pectin methylesterase of juice decreased significantly with the pressure (P < 0.05). Inactivation of polyphenol oxidase and peroxidase could be fitted by two-fraction model and that of pectin methylesterase could be described by first-order reaction model. Titratable acidity, pH, and total soluble solid of juice did not change significantly (P > 0.05). No significant difference was observed in lycopene and total phenolics after high hydrostatic pressure treatment when compared to the control (P > 0.05). Cloudiness and viscosity increased with pressure (P < 0.05) but did not change significantly with treatment time (P > 0.05). a*- and b*-value both unchanged after high hydrostatic pressure treatment (P > 0.05) while L*-value increased but the values had no significant difference among treated juices. Browning degree after high hydrostatic pressure treatment decreased with increase in pressure and treatment time (P < 0.05). Through the comparison of total color difference values, high hydrostatic pressure had little effect on color of juice. The results of this study demonstrated the efficacy of high hydrostatic pressure in inactivating enzymes and maintaining the quality of watermelon juice.

High‐Pressure Inactivation of Enzymes: A Review on Its Recent Applications on Fruit Purees and Juices

“…Two different empirical models were developed to describe the PME and PG inactivation in tomato juice having pH 4.2 (Crelier and others ). However, the first‐order inactivation model was found to be suitable for PG in tomato juice (pH 4.4) as reported by Fachin and others () and for PME in watermelon juice (Liu and others ). Buckow and others () fitted the n th‐order kinetic model for the inactivation of PPO in cloudy apple juice (Figure ).…”

Kinetic modeling of polyphenoloxidase and peroxidase inactivation in pineapple (Ananas comosus L.) puree during high-pressure and thermal treatments

“…predicted that PPO and POD in pineapple puree followed first-order decay (n = 1) within 200-500 MPa/30-60°C. Consequently, PPO and POD from other fruits were also inactivated exponentially (or apparent first-order) with time within high pressure domain like PPO in peach juice ; PPO and POD in watermelon juice (Liu, Zhao, Zou, & Hu, 2013); PPO in avocado and so on. However, Buckow et al (2009) reported that inactivation of apple PPO followed nth order model with n = 2.2.…”

“…Similar type of empirical model considering both Arrhenius and Eyring's equations has been developed in several kinetic studies (Boulekou et al, 2010;Liu et al, 2013;Polydera et al, 2004). The single multi-parameter equation (Eq.…”

Effect of High Pressure Processing on Rheological Properties, Pectinmethylesterase Activity and Microbiological Characteristics of Aloe Vera (Aloe barbadensisMiller) Juice

“…(3): [31] (%) inactivation = 100 − Enzyme activity after treatment Enzyme activity before treatment × 100 (3)…”