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In this study, the impact of the combination of pulsed light (PL) treatments with antimicrobial coatings, consisting of modified chitosan suspensions incorporating carvacrol nanoemulsions, was investigated on the decontamination of fresh-cut cucumber slices. The upper surface of the cucumber slices, with or without the coating deposition, was inoculated with Escherichia coli ATCC 26 to reach a final concentration of 10 7 CFU/g of the vegetable. PL treatments were conducted at different fluence (4, 8, and 12J/cm 2 ) on the inoculated surface of cucumber slices. Results showed that the microbial reduction was only marginally affected by the coating formulation. A slight increase was observed when the carvacrol nanoemulsions were embedded in the chitosan matrix, but microbial reduction levels remained always below 1log cycle. In contrast, the different PL treatments resulted in a statistically significant increase in inactivation with increasing the treatment fluence, reaching 2.6log cycles at the maximum fluence. Remarkably, the combination of the antimicrobial coating with the most intense PL treatments resulted in a strong synergistic effect. For example, by combining a PL treatment at 12J/cm 2 with one of the antimicrobial coatings a microbial reduction >5log cycles was reached. Therefore, it can be concluded that the combination of antimicrobial coatings and PL treatment is a promising method for surface decontamination of fresh-cut vegetables, which could be exploited in view of ensuring their microbiological safety., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this study, the use of chitosan as a clarification agent in the production of clear apple juice (AJ) was investigated, the optimum conditions were determined using RSM, and the effects on the quality of AJ were analyzed during storage at 4 °C and 20 °C for 4 months. Optimum conditions for clarifying the AJ were chitosan concentration of 191.6 mg/100 ml juice, the process temperature of 20 °C and process time of 30 min. Changes in quality characteristics such as turbidity, pH, acidity, color, total monomeric anthocyanin, total phenolic, and protein contents were evaluated and compared to traditional clarification. Alicyclobacillus acidoterrestris causes significant safety issues in fruit juice industry; therefore also the antimicrobial effect of chitosan on A. acidoterrestris during the clarification process was examined. The results showed that clear AJ production can be achieved by the clarification step with direct chitosan addition, without the need for enzymatic treatment. However, the microbial reduction of A. acidoterrestris during the clarification process was not found to be significant. [ABSTRACT FROM AUTHOR]

Chitosan is a modified and natural carbohydrate polymer which is obtained from the partial deacetylation of chitin, and includes the copolymer of glucosamine and N-acetyl glucosamine. Chitosan, which is a microbial polysaccharide, is used as an antimicrobial agent for its bacteriocidal and fungicidal functions. In addition to these properties, it is also used for edible film-forming, reducing the acidity of fruit juices, fining agent, browning inhibitor, and color preservative in the fruit and vegetable industry. Chitosan as a biopolymer can be obtained from many natural sources, has a wide application area in the fruit and vegetable industry due to its non-toxic properties involving living organisms, its biodegradability, biocompatibility, chemical, and physical properties because it shows superior features compared to the other biopolymers. In this review, the use of chitosan, which has not been used as a widespread application in the fruit and vegetable processing industry, will be summarized. [ABSTRACT FROM AUTHOR]