Effect of ohmic heating on physicochemical, bioactive compounds, and shelf life of watermelon flesh‐rind drinks

Abstract

The effect of thermal treatments on physicochemical, bioactive compounds, and shelf life of watermelon flesh-rind drinks was evaluated. An attempt was made for the byproduct utilization of watermelon rind as one of the major ingredient. Three different blends of watermelon flesh and rind juices (T1(100:0), T2(90:10), and T3(80:20), respectively) were pasteurized by ohmic and thermal heating (80 ± 1 C for 3 min) and were stored at refrigerated condition for 90 days. It was found that, thermal treatments and storage induced a significant change in all the quality parameters and ohmic heating for pasteurization was effective in obtaining superior quality watermelon drinks. TSS, pH, reducing sugar, total sugar, viscosity, and overall acceptability, showed a significant difference between the two heating methods while nonsignificant effect was observed for titrable acidity and browning index and citrulline content at 5% level of significance. The microbial counts were lower for ohmic heated pasteurized watermelon juices than thermal pasteurization during entire storage period. Ohmically pasteurized treatments T2 and T3 were microbiologically safe while T2 was best organoleptically. Ohmically pasteurized drink T2 treated with @1.00% beetroot and @2.00% fennel extract was acceptable in respect of all quality parameters up to 90 days under refrigerated storage.

Development and storage stability of value‐added watermelon fruit butter by incorporating watermelon rind byproduct

“…The level of reduction was significantly higher ( p < .05) in treatments with 100% WMF and 15% WMR pulp as compared to the treatments with 10% WMR powder and 6% WMR extract. The decrease in TPC and TFC results of treatment with 100% WMF was in line with the findings reported in WMR juice incorporated watermelon flesh drink during 90 days of storage (Kumar et al, 2021). During storage, the decrease in TPC and TFC could be due to the degradation and oxidation of polyphenolic compounds and their polymerization with protein.…”

“…The decline in TA could be due to the oxidation of reducing sugars and ascorbic acid, acidic hydrolysis of polysaccharides and non-reducing sugars (Kanwal et al, 2017). The results regarding the physicochemical parameters of WMR-enriched watermelon fruit butter are in agreement with the findings in grape peel jam after 60 days of storage (Amorim et al, 2019) and WMR juice incorporated watermelon flesh drink after 90 days of storage (Kumar et al, 2021). In the present study, it was found that the incorporation of WMR in the form of extracts was more effective in preserving the acidity and pH as compared to other treatments during storage.…”

“…However, the growth was within the safe limit such as less than 1 × 10 3 CFU/g. Kumar et al (2021) reported that yeast, mold, and total plate count were steadily increased in all treatments of WMR‐incorporated WMF drink during 60 days of storage. Mokhtar and Ibrahim (2020) also reported an increase in the microbial count but the total bacteria, yeast, and mold count were less than 10 CFU/ml in pomegranate peel and guava leaf extract incorporated guava nectar during 6 months of storage at room temperature (25 ± 5°C).…”

“…The heat treatment during processing and storage significantly ( p < .05) decreases the citrulline content in all treatments except the treatment with 6% WMR extract. The reduction in citrulline content could be due to the oxidative reactions that modified the structure of amino acids and also the degradation of this amino acid into low molecular weight carboxylic acids (Kumar et al, 2021). Similarly, Aguayo et al (2015) reported a decrease in citrulline content in watermelon juice enriched with L‐citrulline during 50 days of storage.…”

Effect of Fermented Matrix on the Color and Stability of Strawberry and Blueberry Anthocyanins during the Storage of Fruit Yogurts and Soy-Based and Bean-Based Fruit Yogurt Alternatives

“…This process could potentially lead to a partial inversion of sucrose, resulting in an overestimation of refractometer readings. A similar effect was observed in research conducted by Kumar et al (2022) [21] where the hydrolysis of sucrose to glucose and fructose increased the soluble solids content in beverages. Additionally, a slightly higher acidity was observed compared to the assumed recipe (0.65 g/100 g).…”