The effect of ultrasound (US), osmotic dehydration (OD), and osmosonication (OS) pretreatments on total phenolic content (TPC), total flavonoids content, (TFC), phytochemical constituents (gingerol derivatives and diarylheptanoids), polyphenol oxidase (PPO), peroxidase (POD), 2,2‐azino‐bis‐(3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS), cupric ion reducing capacity (CUPRAC), 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH), ferric reducing antioxidant power capacity (FRAP), and color of ginger slices dried under relative humidity convective dryer was investigated. OS pretreatment improved the preservation of TPC (13.80–34.79 mg GAE/g d.w), TFC (26.46–62.16 mg CE/g d.w), ABTS (30.37%–86.10%), CUPRAC (36.89–73.97 mg/g), DPPH (50.57%–92.60%), FRAP (26.44‐83 mg/g), and phytochemical constituents than US and OD. The OS‐treated sample was more effective in inactivating both PPO (12.09%–35.93%) and POD (16.21%–39.58%) enzymes compared to US and OD‐treated samples. However, US pretreatment retained the color quality of dried ginger slices than the OS and OD treatments. OS pretreatment (5.43) also increased the total color change (ΔE) of the dried ginger samples compared to US (2.81) and OD (4.60). Practical applications Ginger is commonly used in the food, beverage, and pharmaceutical industries owing to their distinctive flavor and various health potentials. However, its high moisture content makes its inappropriate for long‐term storage which results in its high perishability. Drying is one of the most common techniques to prolong its shelf life. Hence, any pretreatment for ginger that reduces the moistures content and lessens the drying time by preserving the quality of the crop is of vital importance. Ultrasound, osmotic dehydration, and osmosonication are novel pretreatment techniques that are widely used prior to drying of various agricultural products due to its numerous advantages over conventional methods. Its application in drying of foods could help shorten the drying time, reduce processing costs, improve energy consumption and efficiency, and preserve the physical and nutritional properties of the dried product. The current findings will also offer more information for selecting pretreatment techniques for ginger drying.

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The productiveness of ultrasound (US) is affected by its frequency, power, and time, which has been reported to be very effective during food treatment when combined with other techniques of treatments. The study was aimed to evaluate the effect of mono-frequency (MFU), simultaneous dual-frequency (SDFU), and simultaneous tri-frequency US (STFU) at treatment times of 5-25 min on microbial inactivation and nutritional quality of cherry tomato. Results revealed that within 10 min of sonication, SDFU was most effective compared with MFU toward inhibiting the spoilage microorganisms, delaying ripening as well as maintaining firmness, total phenolic, flavonoid, and antioxidant of the fruit during 21 days of storage at 4°C. Although STFU caused a higher reduction in microbial load after treatment, it, however, showed several adverse effects on the fruit during storage. Overall, SDFU treatment had great potential in preserving shelf life and nutritional value of cherry tomato during storage. Practical applicationsUS treatment has been implemented toward improving the shelf life of fruit and vegetables. However, a high desirable result has been related to its combination with other physical or chemical methods. The remarkable inactivation of microorganisms obtained for the dual-and tri-frequency treatments under this study would contribute to the application of a nonthermal technique in the reduction of contaminants on ready-to-eat fresh products including cherry tomato. Furthermore, the positive effect of this treatment on the quality of the cherry tomato during storage indicated that this technique could be used to replace the common practice of combining US with chemical treatment in food preservation industries. Nevertheless, further exploration is needed toward determining the synergistic effect of these treatments with heat (thermosonication). | MATERIAL AND ME THODS | Chemicals and reagentsAnalytical grade chemicals and reagents obtained from Sinopharm Chem. Reagent, Ltd, China were used for this study. | Sample preparationMature red cherry tomatoes (Lycopersicon esculentum, cv. Jutou) were purchased from a local market in Zhenjiang (China) and stored for 24 hr at 4°C before used. Damaged or rotten tomatoes were removed and sorted to have unified sizes (11-13 g) and shapes (roundlike). Thereafter, it was washed with distilled water, dried by hand wiping with tissue papers and taken for treatment. | Simultaneous multifrequency US treatmentThe simultaneous multifrequency US (SMFU) (developed by Jiangsu University, China), is coupled with several frequency generators and maximum output power of 300 W. It can operate as mono-frequency US (MFU) and simultaneous multifrequency US (SMFU). The former operates on single frequency, while the latter works in simultaneous dual-frequency US (SDFU) and simultaneous tri-frequency US (STFU) modes. The simultaneous mode involved two or more frequencies with concurrently pulse on and off time. Wang et al. (2016) gives more details about the working mode, principles, and figures of ...

Decontamination of meat is commonly practiced to get rid of or decrease the microbial presence on the meat surface. Dielectric barrier discharge cold atmospheric plasma (DBD‐CAP) as innovative technology is a food microbial inactivation technique considered in high regard by food scientists and engineers in present times. However, cold atmospheric plasma application is at the experimental stage, due to lack of sufficient information on its mode of action in inactivating microbes, food shelf‐life extensibility, whereas, the nutritional value of food is preserved. In this review, we have appraised recent work on DBD‐CAP concerning the decontamination treatment of meat products, highlighting the processing value results on the efficacy of the DBD‐CAP microbial inactivation technique. Also, the paper will review the configurations, proposed mechanisms, and chemistry of DBD‐CAP. Satisfactory microbial inactivation was observed. In terms of DBD‐CAP application on sensory evaluation, inferences from reviewed literature showed that DBD has no significant effect on meat color and tenderness, whereas in contrast, TBARS values of fresh and processed meat are affected. DBD seems economically efficient and environmentally sustainable.

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