Optimization of Thermal and Thermosonication Treatments on Pectin Methyl Esterase Inactivation of Sour Orange Juice (C itrus aurantium )

Abstract

The objective of this study was to analyze and optimize the critical process parameters in inactivation of pectin methyl esterase (PME) in sour orange juice by thermal and thermosonication processes using response surface methodology. A central composite design was employed for experimental design and process optimization. The thermal inactivation of PME was carried out at temperatures between 40 and 80C for 5-25 min. At thermosonication process, temperature and time were kept as before while the process was optimized with an ultrasound intensity of 60-100 W. Simultaneous application of ultrasound and thermal process enhanced the enzyme inactivation. The optimal process condition for PME inactivation in thermal process and thermosonication (at 80 W) were 21.80 min at 75C and 9.8 min at 63C, respectively. The results indicate that thermosonication of sour orange juice could entirely inactivate the PME. PRACTICAL APPLICATIONSToday, preservation by elevation of temperature for short periods of time (up to 90C) is still the most common processing method for microbial or enzyme inactivation that leads to longer shelf life. Because of the exposure to high temperature, this thermal method has disadvantages for many food products particularly fruit juice. The production of new substances from heat-catalyzed reactions and the modification of macromolecules as well as the deformation of plant and animal structures may reduce in a loss of quality. Therefore, thermal treatment can cause undesirable alterations of sensory attributes, i.e., texture, flavor, color, smell and nutritional qualities, i.e., vitamins and proteins. Ultrasound is an efficient nonthermal (minimal) processing alternative.

Optimal thermoultrasound processing of jackfruit ( Artocarpus heterophyllus lam.) nectar: Physicochemical characteristics, antioxidant properties, microbial quality, and fatty acid profile comparison with pasteurized nectar

“…Temperature ( b 1 ) significantly influenced ( p < .001) the percentage of residual activity of PME (Table 2), so when the temperature increased the residual activity decreased (Figure 2). Studies in tomato juice (Adekunte et al., 2010), sour orange (Koshani et al., 2015), prickly pear blend (Cruz‐Cansino et al., 2016), and blackberry (Cervantes‐Elizarrarás et al., 2017) showed similar effects.…”

Influence of thermosonication treatments on bioactive compounds and sensory quality of fruit (Haematocarpus validus ) juice

“…The mechanical force exercised by cavitation leads to sudden burst of air bubbles produced through TS process with acoustic field can be occurred enzyme inactivation in fruit juice. Free radicals, intrinsic and extrinsic parameters are important factors to be considered and optimized level causes inactivate enzymes during TS process (Koshani, Ziaee, Niakousari, & Golmakani, ). The changes in color values may adversely affect the organoleptic properties and ultimately degrade the quality of juice, however, these changes could not be perceived by the naked eye in the present study.…”

Optimising Tropical Fruit Juice Quality Using Thermosonication-Assisted Extraction via Blocked Face-Centered Composite Design

“…In juice extraction, ultrasound can produce greater yields of juice [14], reduce time of juice extraction because of heat and mass transfer enhancement, and save extraction energy via facilitating extraction at medium temperature levels. The combination of low frequency ultrasound with mild heat can help in reducing processing temperature and time by 16 and 55%, respectively, minimising the negative effects on fruit juices quality and makes the processing more economically feasible [15]. The combination of ultrasound and mild heat treatment is also known as thermosonication.…”

“…The thermosonication treatment is useful in acting against thermo-resistant enzymes where it is difficult to denature by thermal treatment alone. The use of extreme heat could lead to adverse changes in juice quality like cooked flavour and caramelisation [15][16][17][18][19]. Since enzymes are more thermo-resistant than microorganisms in citrus juices, the inactivation of enzymes promises achievement of required number of microbial destruction for spoilage prevention [20].…”