The effect of pasteurization and thermosonication on the quality of star fruit (Averrhoa carambola) juice was reported in the present study. Freshly extracted star fruit juice was pasteurized and thermosonicated to compare the effect on physiochemical properties, antioxidant activity, total phenolic content (TPC), total flavonoid content (TFC), ascorbic acid levels, microbial populations, and sensorial properties. The results were compared with the raw star fruit juice. The treatments did not show any significant (p < .05) variations in pH, total soluble solids, and titratable acidity. A significant (p < .05) increase in antioxidant activity, TPC, TFC, ascorbic acid content, cloud index, and browning index of thermosonicated juices was observed. Pasteurization and thermosonication treatments also displayed significant effect in the reduction of microbial populations. Thus, findings in this study revealed that thermosonication may be a viable option for fruit juice industry, especially, for star fruit processing. Practical applications Ultrasound processing is an emerging nonthermal technique which can be utilized in the processing of liquid food products. In general, fruit juices are processed through thermal treatments to keep the safe microbial levels. However, thermal processing adversely affects the quality of food products. The present study demonstrated the application of thermosonication that effectively maintained the quality of star fruit juices. Furthermore, it can be added that, thermosonication may be employed as a suitable technique to improve the quality parameters of star fruit juice.

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The present work evaluated the influence of different thermosonication conditions on the quality improvement of elephant apple (Dillenia indica) juice. The juice was processed under thermosonication at different temperatures (30–50°C) for different time periods (15–60 min). The results of sonication treatments were compared with fresh and thermally treated juices. The objectives of the research work were to determine the effect of thermosonication on the quality attributes such as pH, titratable acidity (TA), total soluble solids (TSS), total phenolic contents (TPC), total flavonoid contents (TFC), antioxidant activity (AA), ascorbic acid levels, microbiological, and sensory properties. pH, TA, and TSS of thermosonicated and pasteurized juice samples did not produce any significant (p < .05) differences. From the experimental results, it was also seen that thermosonication has improved the quality of elephant apple juice by increasing the levels of TPC, TFC, and AA significantly (p < .05) and ensuring the microbial safety of juices. Furthermore, the findings of the present study indicated that the thermosonication can be employed for processing of elephant apple juice as a replacement method for thermal processing with enhanced quality.Practical applicationsUltrasound processing is one of the new method which has been applied widely to improve the shelf life of fruit juices without altering the quality attributes of juices. Commonly, thermal processing technologies are applied to improve the keeping quality of fruit juices, but it has some detrimental effects on the final quality of fruit products. So, ultrasound processing can be utilized as an alternative method to thermal processing. In the present work, ultrasound processing was applied to enhance the quality of elephant apple juices.

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The effect of gastro intestinal digestion on total phenolic contents (TPC), total flavonoid contents (TFC), radical scavenging activity (RSA) and vitamin C levels of apple (Malus domestica) pomace and a local variety of jujube (Ziziphus mauritiana) pomace was evaluated after drying at 110 °C for 3 h in a hot air oven. The physicochemical properties and functional properties of apple and jujube pomaces were also assessed. Prior to digestion, apple pomace displayed greater levels of TPC, RSA and vitamin C (17.30 ± 0.59 GAE/g DW, 81.16 ± 3.27%, 0.078 ± 0.01 g/L, respectively) in comparison with jujube pomace (16.90 ± 0.66 GAE/g DW, 54.65 ± 2.09%, 0.069 ± 0.01 g/L, respectively), whereas, TFC level was found to be higher in jujube pomace (19.22 ± 0.87 QE/g DW). After digestion, both samples showed an increase in TPC (56.17 ± 2.14 and 52.01 ± 2.18 GAE/g DW for apple and jujube pomaces) and TFC levels (48.45 ± 1.87 and 53.82 ± 2.34 QE/g DW for apple and jujube pomaces) and it was perceived almost 3 to 4 times higher than the TPC and TFC of the samples before digestion. But, RSA of the fruit pomaces were found to be affected by the in vitro digestion which was observed as 54.65 ± 2.09 and 81.16 ± 3.27% respectively for apple and jujube pomaces. It may be suggested that the fruit powders may be incorporated in developing new functional foods rich in bio active compounds and thus can be utilized in different food applications.