Assessment of quality changes of tangor fruit juice after pasteurization and thermosonication treatments

Abstract

In recent years, thermosonication (TS) has been considered as a substitute to conventional heat treatments as it improves the quality characteristics of fruit juices. In the present research work, the impact of pasteurization (90 ± 2 C for 1 min) and TS on the quality of tangor fruit juice was examined and findings of the work were compared with freshly prepared juice. The quality characteristics, such as bioactive compounds, microbial counts and physicochemical properties were checked for all samples. After TS, the levels of total phenolic content (TPC) (683.25-747.84 μg gallic acid equivalents [GAE0/ml]), total flavonoid content (TFC) (61.76-71.51 μg quercetin equivalents [QE]/ml) and anti-oxidant activity (AOA) (73.27-83.63%) of tangor juices were improved as compared to fresh (TPC À 584.84 μg GAE/ml, TFC À 34.65 μg QE/ml and AOA À 49.71%) and pasteurized juices (TPC -471.74 μg GAE/ml, TFC -26.64 μg QE/ml and AOA -38.19%). But, a slight decrement in ascorbic acid content was perceived in thermosonicated juices (24.48-27.26 mg/100 ml) as compared to fresh tangor juice (45.55 mg/100 ml) but higher than pasteurized juice (22.55 mg/100 ml). TS also reduced the microbial populations in tangor juices with minor changes in the physicochemical properties as compared to fresh juices. Therefore, TS may be used effectively for the treatment of tangor juices to produce a product with better levels of bioactive compounds.

Effect of Thermosonication on Amino Acids, Phenolic Compounds, Sensory Properties and Microbial Quality in Freshly Squeezed Verjuice

“…The thermal pasteurization process caused decreases in the bioactive components of verjuice. Similarly, it was found in many reports that the thermosonication process preserves or enriches bioactive components better than thermal pasteurization [12,32]. The reason for the enrichment or better preservation of bioactive components is that thermosonication processes enhance bioactive release and levels.…”

Application of thermosonication for guava juice processing: Impacts on bioactive, microbial, enzymatic and quality attributes

“…Thermosonication (TS), known by another name as ultrasonic-assisted heat treatment, has gained increasing attention and application in the processing of liquid products like juices, milk, beverages and others, due to its capability to inactivate the enzymes and microorganisms with the least possible loss of quality in comparison to traditional thermal treatments [9] , [26] , [45] , [53] . TS of tangor juice has been found to be significantly more effective in preserving/enhancing the levels of bioactive compounds compared to traditional pasteurization [7] . TS has shown substantial enzyme inactivation (lipoxygenase (LOX) and peroxidase (POD) for almond (Prunus dulcis) milk while enhancing the bioavailability of total phenolic, flavonols, flavonoids, condensed tannin contents, and antioxidant activity when compared to pasteurization [25] .…”

Integrated approach of ultrasound with mild heat treatment on the quality characteristics of yacon (Smallanthus sonchifolius) tuber juice

“…To determine the BI, equivalent segments of ethanol and overhead solution (5 ml each) were mixed and stirred. The sample mixture was then measured 420 nm wavelength using a spectrophotometer (Basumatary et al, 2022).…”