Ultrasonic Effects on the Quality of Mulberry Juice

Ultrasound-assisted enhancement of bioactive compounds in hawthorn vinegar: A functional approach to anticancer and antidiabetic effects

In this study, the effects of ultrasound treatment on bioactive components and functional properties of hawthorn vinegar (Crataegus tanacetifolia) were investigated. Parameters such as total phenolic compound (TPC), total flavonoid content (TFC), ascorbic acid (AA), DPPH radical scavenging activity and CUPRAC reducing capacity were optimised by surface response method (RSM) and 14 min duration and 61.40 % amplitude were determined as the most suitable treatment conditions. The results showed that ultrasound treatment improved the antioxidant properties of hawthorn vinegar by increasing TPC, TFC, DPPH and CUPRAC values. In addition, it was observed that hawthorn vinegar samples exhibited anticancer effects in cell culture experiments. In experiments on A549 (lung), MCF-7 (breast) and HT-29 (colon) cancer cell lines, ultrasound-treated vinegar increased apoptotic effects, suppressed cell migration and reduced necrosis rates in some cell lines. In particular, ultrasound treatment of vinegar resulted in a reduction in the expression of anti-apoptotic genes (BCL-2 and XIAP) and an enhancement in the expression of pro-apoptotic genes (BAX). These findings suggest that ultrasound technology preserves and enhances the bioactive components of hawthorn vinegar, improves its anticancer properties and increases its potential for use as a functional food product.

Comparative Evaluation of Conventional and Emerging Maceration Techniques for Enhancing Bioactive Compounds in Aronia Juice

Ultrasound and microwave maceration techniques have been utilised to lower production costs and reduce processing time, while also preventing the degradation of nutrients like phenolics and vitamin C and preserving physical properties such as colour and viscosity. In this study, the effects of several traditional (cold, enzymatic, and thermal) and innovative (ultrasonic and microwave) maceration methods on some quality parameters of aronia juice were investigated. Microwave maceration significantly impacted the soluble solids content of the analysed juices and resulted in noticeably darker juice samples compared to the controls, with lower L*/lightness (20.1) and b*/blue-yellowness (-3.2) values and an increased a*/redness value (1.7). Different maceration methods also significantly impacted the rheological properties of the treated juices, among which MW treatment consistently showed a higher viscosity. Sorbitol and fructose were the main sugars identified, while malic acid and quinic acid accounted for 85% of the total acid content. Significant increases in the total sugar and acid concentrations were obtained in the juice samples from ultrasonic, microwave, and enzymatic maceration, while thermomaceration had no significant effect. The concentration of total phenolics ranged from 6.45 g/L in the thermomaceration samples to 9.86 and 14.07 g/L in the ultrasonic and microwave samples, respectively. The obtained results suggest that ultrasonic and microwave technologies were superior in terms of colour improvement and the extraction of sugars, acids, and phenolic compounds compared to traditional maceration methods. Ultrasound and microwave technologies present possible approaches to the improvement of aronia juice production in comparison to traditional methods.

Impact of Ultrasound Pretreatment on Juice Yield and Bioactive Content in Juice Produced from Selected Berries Fruit

The aim of the work was to investigate the effect of ultrasound application during juice pressing. The impact on pressing yield and extraction of bioactive compounds during production of juice from strawberry, blackcurrant and raspberry was evaluated. Juice pressing was carried out after four kinds of mash pretreatment. The tested objects were heated to 55 °C, treated by ultrasound, and/or macerated with an enzyme. The obtained juices were analyzed for the content of bioactive compounds and compared to the 'Control' sample, which was the juice pressed without any pretreatment. Although the results presented here do not conclusively show that enzymatic maceration can be completely replaced by the use of ultrasound, in the case of strawberry and raspberry fruit, juice yield after ultrasound treatment increased almost as much as after enzymatic maceration. Additionally, in the case of raspberry fruit, the antioxidant activity of the juice samples was definitely improved when ultrasound was used. The results from this experiment also showed that it is possible to separate the effect of temperature from the effect of mechanical and chemical actions in ultrasound treatment.

Sonication and thermal treatment of pineapple juice: Comparative assessment of the physicochemical properties, antioxidant activities and microbial inactivation

Sonication is a novel processing method that is perceived as a substitute for heat treatment to ensure the safety of juice while reducing the loss of nutrients during processing. The impacts of sonication and thermal processing on pineapple juice, including physicochemical properties, antioxidant activities, and microbial inactivation, were studied. Pineapple juice was sonicated at 100 W and 140 W (for 5, 10 and 15 min) and heat-treated at 70 °C, 80 °C and 90 °C (for 1 min). Results indicated minor alterations in physicochemical characteristics after sonication and thermal processing, while sonication treatment showed better retention of the color, clarity, and browning index of pineapple juice. Moreover, sonication significantly increased the bioactive compounds (total carotenoids, ascorbic acid, phenolics, and flavonoids) and boosted the antioxidant activity of pineapple juice compared to the heat-processed juice. Although sonication reduced the microbial load significantly with the increasing exposure time, it could not thoroughly inactivate microorganisms like thermal treatment. Therefore, optimal sonication processing conditions are required to be determined. This study will help the food processors utilize sonication treatment in pineapple juice processing plants to inactivate microorganisms thoroughly while also boosting the nutritional value.

Pulsed Electric Field (PEF) and High-Power Ultrasound (HPU) in the Hurdle Concept for the Preservation of Antioxidant Bioactive Compounds of Strawberry Juice-A Chemometric Evaluation-Part I

This work investigated the influence of pulsed electric field (PEF) and high-power ultrasound (HPU) combined with hurdle technology to preserve the bioactive compounds (BACs) content and antioxidant activity in stored strawberry juices. PEF was performed at 30 kV cm-1, 100 Hz during 1.5, 3, and 4.5 min, while HPU was performed at 25% amplitude and 50% pulse during 2.5, 5.0, and 7.5 min. Total phenols and hydroxycinnamic acids were the most stable BACs during the hurdle treatment without influence of the duration of both treatments, while flavonols and condensed tannins showed a significant stability dependence with respect to the duration of both treatments. Total phenols were also stable during storage, in contrast to the individual groups of BACs studied. A chemometric approach was used to optimize the parameters of the hurdle treatments with respect to the highest level of BACs and the antioxidant activity of the treated juices. In general, shorter treatment times in the hurdle approach resulted in better stability of BACs and antioxidant activity. The hurdle technology investigated in this study has the strong potential to be an excellent concept for optimizing the operating parameters of PEF and HPU technologies in the preservation of functional foods.

Effect of Ultrasound and Enzymatic Mash Treatment on Bioactive Compounds and Antioxidant Capacity of Black, Red and White Currant Juices

Ultrasound treatment is recognized as a potential technique for improvement in the nutritional values of fruit juices. This study was initiated with the objective of evaluating bioactive compounds and some important quality parameters of black (BC), red (RC) and white (WC) currant juices obtained from fruit mash preliminarily treated by enzymes combined with ultrasound. Individual and total phenolic content (TPC), anthocyanins, color parameters, ascorbic acid, antioxidant capacity (TEAC), juice yield, pH, titratable acidity, and soluble solids were investigated. Significant increases in the levels of TPC and antioxidant capacity of sonicated samples were observed. However, ultrasound treatment had no effect on individual phenolic compounds of juices. Sonication of mash before juice pressing did not cause any noticeable changes in ascorbic acid content. Only in the case of WC was an increase in content of vitamin C noticed. The color of juices obtained after treatment was similar to the control sample. It was demonstrated that enzymatic combined with ultrasound treatment of mash for different colored currant fruit did not have any dismissive effect and could even improve some parameters of the juice obtained.