Disinfection of fresh chicken breast fillets with in-package atmospheric cold plasma: effect of treatment voltage and time

Authors: WANG, JIAMEI - Hainan University; Zhuang, Hong; Lawrence, Kurt; ZHANG, JIANHAO - Nanjing Agricultural University

Submitted to: Journal of Applied Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/4/2017
Publication Date: 11/15/2017
Citation: Wang, J., Zhuang, H., Lawrence, K.C., Zhang, J. 2017. Disinfection of fresh chicken breast fillets with in-package atmospheric cold plasma: effect of treatment voltage and time. Journal of Applied Microbiology. 124:1212-1219.

Interpretive Summary: Chicken is the most popular meat in the world, and its consumption has been increasing rapidly in the past decades. During transportation and storage, spoilage and food safety concerns arise from microorganism contamination. To extend shelf life and insure food safety of fresh chicken meat, it is important to eliminate and control microorganisms on meat surfaces during processing and post-processing handling. Thermal treatment technologies are widely used to sterilize microorganisms on meat and its products, but thermal processing is not reasonable to treat fresh meat as it alters both its sensory quality and nutrients. Non-thermal sterilization methods are necessary to be used for retaining quality of fresh meat products, but many of the commonly used methods have disadvantages such as formation of unpleasant aroma, high equipment cost, and lower disinfection effectiveness to spores. For this reason, it is necessary to develop new non-thermal techniques to reduce the microbial contamination for fresh foods. Atmospheric cold plasma (ACP) is an emerging non-thermal antimicrobial treatment for food products. ACP has been demonstrated to disinfect microbes on meat as well as produce products successfully. Our overall goal is develop an effective ACP system to treat packed raw chicken meat and extend its shelf life during refrigerated storage. The specific objective for this study was to evaluate how electric voltage and durations of an in-package ACP treatment influence microbial growth. Our results showed that the effects of ACP treatment can significantly reduce microbial populations on raw chicken breast meat. Increasing ACP treatment voltage from 55 to 80 kV for 3 min or increasing ACP treatment time from 3 to 9 min at 80 kV does not affect microbiological quality and pH. However, increasing treatment time overall 3 min may affect the appearance of treated raw meat products.

Technical Abstract: Effects of treatment voltage and time of in-package atmospheric cold plasma (ACP) were studied on ozone formation, microbiological quality, surface color, and pH of fresh chicken fillets. Samples were sealed in food trays in air, treated with a dielectric-barrier-discharge (DBD) ACP system, and stored at 4 ' for 24 h or 3 d before microbiological quality, CIE L*a*b*, and pH were evaluated. Increasing voltage from 55 to 80 kV resulted in increasing O3 concentration inside packages, but had no significant effect (P > 0.05) on bacterial populations, pH, and color of samples measured after 24-h storage at 4 oC. Although there were no differences (P > 0.05) between treatment times (3 to 9 min at 80 kV) in O3 formation, pH, L* values, and microbial populations after 3-d storage at 4 oC, the bacterial populations on ACP-treated samples were significantly lower (P < 0.05) than those on non-treated control. Treatments at 80 kV for more than 3 min reduced (P < 0.05) a* and b* of fillets. Changing ACP treatment voltages did not significantly affect natural microflora, color, or pH of raw chicken fillets after 24-h storage at 4 oC. However, the treatments for 3 to 9 min, which did not differ from each other, significantly reduced microflora populations and affected redness and yellowness of treated raw chicken meat compared with non-treated samples after 3-d refrigerated storage. Our data demonstrate that effects of in-package DBD-based ACP treatment on the microbiological quality and pH of raw chicken meat do not vary with treatment voltage (from 55 to 80 kV) and time (between 3 to 9 min). However, increasing treatment time overall 3 min may affect the appearance of treated raw meat products.