Microbial Quality and Shelf Life of Blueberry Purée Developed Using Cavitation Technology

Non-thermal hydrodynamic cavitation processing of tomato juice for physicochemical, bioactive, and enzyme stability: Effect of process conditions, kinetics, and shelf-life extension

Fresh tomato juice was processed by hydrodynamic cavitation (HC) at 5 to 15 psi pressures for 5–30 min. A full factorial design was applied to optimize the HC treatment of tomato juice quality. Optimal conditions were recorded at 10 psi for 10 min, which showed no significant (p < 0.05) change in lycopene content to that of freshly obtained unprocessed tomato juice (control). After processing, the retention of 93% ascorbic acid and 96.6% of total phenolic compounds (TPC) was observed. Similarly, sedimentation and viscosity were mildly affected by HC processing (89.2 and 94.4% of values in the treated sample, respectively). While pH, total soluble solids (TSS), titratable acidity (TA) of HC treated sample remained unchanged (p < 0.05). The results were also compared with the conventional thermally processed tomato juice (90 °C for 90 s). Although thermal treatment resulted in the inactivation of 92.2% of pectin methylesterase and a 5 log reduction in total plate counts, it also showed significant reductions in ascorbic acid (61.4%), TPC (72.3%), and physical properties (37.7% of SI and 83.2% viscosity). However, HC processing could achieve a maximum of 4.9% inactivation of PME and 1 log reduction at high treatment conditions, respectively (15 psi for 30 min). The shelf-life study showed more retention of bioactives and better physicochemical properties in tomato juice samples stored at 4 °C for 15 days than the control. Sensory evaluation revealed that the overall acceptability of the optimized HC treated (0.714) sample was better than the thermally treated sample (0.591). The observed results concluded that HC-treated tomato juice was comparatively better than thermally-treated tomato juice in retaining bioactive compounds. Consequently, HC constitutes a promising approach in food processing to improve and retain the beneficial properties of tomato juice.

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Hydrodynamic cavitation is a sustainable alternative to obtain health-promoting foods.

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The optimum HC conditions were 10 psi for 10 min for tomato processing.

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Stability of lycopene was observed in HC treated juice.

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HC processed tomato juice showed excellent stability compared to untreated juice.

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HC treated tomato juice had shelf-life up to 15 days at 4 °C with good sensory and quality attributes.

Strategies for Microbial Decontamination of Fresh Blueberries and Derived Products

Increasing consumption of blueberries is associated with appreciation of their organoleptic properties together with their multiple health benefits. The increasing number of outbreaks caused by pathogenic microorganisms associated with their consumption in the fresh state and the rapid spoilage of this product which is mainly caused by moulds, has led to the development and evaluation of alternatives that help mitigate this problem. This article presents different strategies ranging from chemical, physical and biological technologies to combined methods applied for microbial decontamination of fresh blueberries and derived products. Sanitizers such as peracetic acid (PAA), ozone (O3), and electrolyzed water (EOW), and physical technologies such as pulsed light (PL) and cold plasma (CP) are potential alternatives to the use of traditional chlorine. Likewise, high hydrostatic pressure (HHP) or pulsed electrical fields (PEF) successfully achieve microbial reductions in derivative products. A combination of methods at moderate intensities or levels is a promising strategy to increase microbial decontamination with a minimal impact on product quality.

A review on underwater shockwave processing and its application in food technology

Underwater shockwave processing (USP) is a non-thermal food processing method where a high-energy impulse is generated near a food product submerged in a liquid. The resulting shockwave transfers energy to the food, and is used to improve quality, safety, and nutritional aspects. This review presents the origin and evolution of the technology, principles of shockwave generation, mechanism of action, and applications in the food industry. The most common food application of USP is currently meat tenderization, where it is used to improve the sensory characteristics of meat as a value-added process. The use of USP as a pretreatment process has also been investigated to increase the yield and nutritional value of extracted juice and oil via softening of plant tissues. This technique also has an impact on food-borne pathogens and spoilage microorganisms in food, however, it is more effective when combined with other hurdles. Major challenges facing the industrial implementation of underwater shockwave technology include the lack of appropriate packaging materials resistant to the disruptive effects of shockwaves, the capital investment required, and a lack of regulatory information pertaining to USP. So far, most studies of underwater shockwaves on food are at the laboratory scale and validation stage. Further research endeavors and collaboration between food scientists, engineers, and regulators are necessary to scale up this technology to industrial implementation.

Low-pressure homogenization of tomato juice using hydrodynamic cavitation technology: Effects on physical properties and stability of bioactive compounds

Hydrodynamic cavitation (HC) technology, offers benefits in many processes, specifically due to its low operational cost and simple configuration. In the present work, physical properties, microbial quality and stability of bioactive compounds of HC-treated tomato juice were evaluated considering different processing conditions. Significant effects of the induced cavitation such as a reduction in particle size and an increase in the apparent viscosity were observed in the HC-treated samples. Moreover, the HC-treated tomato juice showed higher stability without sedimentation for 14 days compared to a sedimentation index of 68% observed in samples before treatment and control experiment. Lycopene and phenolic contents in tomato juice were not altered even after HC-treatment. Finally, the microbiological quality was also improved, mainly for the samples treated above 55 °C. Therefore, this technology can be envisaged as a promising strategy for food processing to enhancing desirable properties in juices.