Investigation of the impact of cold plasma pretreatments, long term storage and drying on physicochemical properties, bioactive contents and microbial quality of 'Keitt' mango

There is heightened demand for dried mango fruits with desired nutritional and physicochemical qualities, microbiologically stable and chemical residue free. This has led to the exploration of innovative preservation technologies for the extension of storability prior to processing. This study investigated the impact of cold plasma (CP) treatment on physicochemical properties and microbial stability in fresh and dried 'Keitt' mango during long term storage. Freshly harvested 'Keitt' mangoes were subjected to: CP treatment (for 5 min (CP5) and 10 min, CP10), dipping in "Chronos Prochloraz" for 30 s (industry practice), and untreated group (control). All samples were stored at 11 °C for 30 days, prior to minimal processing and hot air drying at 60 °C. Results after 30 days of storage demonstrated that untreated samples (control) had the highest TSS (15.06 ± 0.32 °Brix), while CP10 pretreated samples had the lowest TSS (13.80 ± 0.06 °Brix) value (p ≤ 0.05). In comparison to the fresh samples post storage, all pretreated dried mango slices retained lower total flavanols with CP5 (13.49 ± 1.64 mg GAE 100/g), CP10 (20.12 ± 1.42 mg GAE 100/g) and SMB (23.89 ± 3.35 mg GAE 100/g), but higher than the dried untreated samples (6.68 ± 0.53 mg GAE 100/g). Yellowness (b∗) of the fresh pulp (38.53 ± 1.73) increased significantly (p ≤ 0.05) with the long-term storage (39.88-46.74) and drying (55.01-64.90). CP pre-treatment combined with drying resulted in ≥2 Log reduction in microbial count. This study shows the potential of cold plasma as a pretreatment for extending storability and maintaining the quality of 'Keitt' mangoes.

Recent trends and technological development in plasma as an emerging and promising technology for food biosystems

The rising need for wholesome, fresh, safe and “minimally-processed” foods has led to pioneering research activities in the emerging non-thermal technology of food processing. Cold plasma is such an innovative and promising technology that offers several potential applications in the food industry. It uses the highly reactive, energetic and charged gas molecules and species to decontaminate the food and package surfaces and preserve the foods without causing thermal damage to the nutritional and quality attributes of food. Cold plasma technology showed promising results about the inactivation of pathogens in the food industry without affecting the food quality. It is highly effective for surface decontamination of fruits and vegetables, but extensive research is required before its commercial utilization. Recent patents are focused on the applications of cold plasma in food processing and preservation. However, further studies are strongly needed to scale up this technology for future commercialization and understand plasma physics for getting better results and expand the applications and benefits. This review summarizes the emerging trends of cold plasma along with its recent applications in the food industry to extend shelf life and improve the quality of food. It also gives an overview of plasma generation and principles including mechanism of action. Further, the patents based on cold plasma technology have also been highlighted comprehensively for the first time.

Impacts of cold plasma treatment on physicochemical, functional, bioactive, textural, and sensory attributes of food: A comprehensive review

Cold plasma processing is a technique that uses electricity and reactive carrier gases, such as oxygen, nitrogen, or helium, to inactivate enzymes, destroy microorganisms, preserve food, and maintain quality without employing chemical antimicrobial agents.The review collates the latest information on the interaction mechanism and impact of non-thermal plasma, as an emerging processing technology, on selected physical properties, low-molecular-weight functional components, and bioactive properties of food. Significant changes observed in the physicochemical and functional properties. For example, changes in pH, total soluble solids, water and oil absorption capacities, sensory properties such as color, aroma, and texture, bioactive components (e.g., polyphenols, flavonoids, and antioxidants), and food enzymes, antinutrients, and allergens were elaborated in the present manuscript. It was highlighted that the plasma reactive species result in both constructive and antagonistic outcomes on specific food components, and the associated mechanism was different in each case. However, the design's versatility, characteristic non-thermal nature, better economic standards, and safer environmental factors offer matchless benefits for cold plasma over conventional processing methods. Even so, a thorough insight on the impact of cold plasma on functional and bioactive food constituents is still a subject of imminent research and is imperative for its broad recognition as a modern non-conventional processing technique.