High-Intensity Ultrasound Processing Enhances the Bioactive Compounds, Antioxidant Capacity and Microbiological Quality of Melon (Cucumis melo) Juice

Abstract

The bioactive compounds, antioxidant capacity and microbiological quality of melon juice processed by high-intensity ultrasound (HIUS) were studied. Melon juice was processed at two ultrasound intensities (27 and 52 W/cm2) for two different processing times (10 and 30 min) using two duty cycles (30 and 75%). Unprocessed juice was taken as a control. Total carotenoids and total phenolic compounds (TPC) were the bioactive compounds analyzed while the antioxidant capacity was determined by DPPH, ABTS and FRAP assays. The microbiological quality was tested by counting the aerobic and coliforms count as well as molds and yeasts. Total carotenoids increased by up to 42% while TPC decreased by 33% as a consequence of HIUS processing regarding control juice (carotenoids: 23 μg/g, TPC: 1.1 mg GAE/g), gallic acid and syringic acid being the only phenolic compounds identified. The antioxidant capacity of melon juice was enhanced by HIUS, achieving values of 45% and 20% of DPPH and ABTS inhibition, respectively, while >120 mg TE/100 g was determined by FRAP assay. Further, the microbial load of melon juice was significantly reduced by HIUS processing, coliforms and molds being the most sensitive. Thus, the HIUS could be an excellent alternative supportive the deep-processing of melon products.

Effects on quality characteristics of ultrasound-treated gilaburu juice using RSM and ANFIS modeling with machine learning algorithm

“…Rodrigues-Rico et al (2022) applied thermal pasteurization and ultrasound treatments to fresh melon juice (DPPH: 29 %). DPPH levels reached 39 % and 46 %, respectively [51] . The observed increase in antioxidant activity in our study, as well as in other research findings, could be attributed to the heightened activity of phenolic compounds and acids, which act as potent free radical scavengers during ultrasound treatment [52] .…”

“…4 ). Rodríguez-Rico et al [51] showed that 10–15 min of ultrasound treatment at 10 ± 2℃ applied to melon juice in 2022 caused an increase in color score by minimizing the color change compared to the control and in the heat treatment investigation carried out by Lepaus et al [65] involving an orange-carrot juice blend, the samples treated for 30 s at 90 ℃ yielded scores of 6.79 ± 1.82 compared to the control sample, which achieved a general acceptability score of 7.64 ± 1.39. On the contrary, the ratings for samples treated with ultrasound for 5 and 10 min at 60 °C were 6.24 ± 2.28 and 4.72 ± 1.87, respectively.…”

Thermal Treatment and High-Intensity Ultrasound Processing to Evaluate the Chemical Profile and Antioxidant Activity of Amazon Fig Juices

“…However, among them there was no significant difference. The effect of the HIUS treatment also caused color change in the melon juices [23] and kiwi [24], which may be related to the oxidation reaction (depending on the treatment time) and/or variation in the concentration of compounds due to sonication.…”

“…Observing the signals of the major compounds, it is noted that in the HT sample that underwent heating only, without the aid of ultrasound, the signals decreased a little. In a study to monitor the quality of orange juice, it was found that heat-treated samples lost their turbidity and had their ascorbic acid content reduced by 7% [30], while high-intensity ultrasound processing enhanced the bioactive compounds on melon juice [23].…”

“…Observing the signals of the major compounds, it is noted that in the HT sample that underwent heating only, without the aid of ultrasound, the signals decreased a little. In a study to monitor the quality of orange juice, it was found that heat-treated samples lost their turbidity and had their ascorbic acid content reduced by 7% [30], while high-intensity ultrasound processing enhanced the bioactive compounds on melon juice [23]. Minor bioactives were identified and quantified by HPLC-DAD, such as gallic acid and its derivatives, protocatechuic acid, cyanidins, p-hydroxybenzoic acid, p-coumaric acid, and syringic acid, trans-ferulic and caffeic acid, epicatechin derivatives, vitexin and rutinoside.…”