• Effects of dielectric barrier discharge (DBD) generated plasma on microbial reduction and quality parameters of fresh mackerel (Scomber scombrus) fillets

      Albertos, Irene; Martín-Diana, AnaBelen; Cullen, P.J.; Tiwari, Brijesh K; Ojha, S. K.; Bourke, Paula; Álvarez, Carlos; Rico, Daniel; National Institute for Food and Agricultural Research (Elsevier, 2017-07-04)
      The effect of atmospheric cold plasma generated by a novel in-package dielectric barrier discharge (DBD) on microbial and quality parameters of mackerel fillets was investigated. DBD voltage (70 kV and 80 kV) and treatment time (1, 3 and 5 min) were studied. Within 24 h of DBD treatment, spoilage bacteria (total aerobic psychrotrophic, Pseudomonas and lactic acid bacteria) were significantly reduced. However, significant effects on lipid oxidation parameters (PV, Dienes) were observed for the treated samples. Both studied treatment factors, treatment voltage and time, significantly affected anti-microbial efficacy and lipid oxidation. Nevertheless, no changes in pH or colour (except for L*) were observed. These results suggest atmospheric cold plasma generated by DBD could be implemented as technology for fish processing, retaining product quality over its shelf life. However, further investigations are needed in order to implement this technology and to control and mitigate its limitations, mainly associated to increased oxidation.
    • Shelf-life extension of herring (Clupea harengus) using in-package atmospheric plasma technology

      Albertos, Irene; Martin-Diana, A. B.; Cullen, Patrick J.; Tiwari, Brijesh K; Ojha, K. Shikha; Bourke, Paula; Rico, D.; Regional Government of Castille and Leon, Spain; NUGAFU-PEP 2011/769 (Elsevier, 2017-09-17)
      Atmospheric cold plasma is a green and emerging technology, highly interesting to the food industry for its application. Dielectric Barrier Discharges (DBD) can generate atmospheric cold plasma inside sealed packages filled with air through the use of high voltages. This study investigated the use of a large gap DBD design to generate a plasma discharge within the headspace of packaged herring fillets, and its effects on microbiological and quality markers of the fish stored for 11 days at 4 °C. DBD plasma treatment conditions were 70 kV or 80 kV for 5 min treatment time. Results showed that the microbial load (total aerobic mesophilic, total aerobic psychrotrophics, Pseudomonas, lactic acid bacteria and Enterobacteriaceae) were significantly (p < 0.05) lower in the treated samples compared to the control samples. However, samples exposed to the lowest applied voltage better retained key quality factors (lower oxidation and less colour modification). DBD-treatment caused a reduction in trapped water in the myofibrillar network (T21), identified using low-field nuclear magnetic resonance of protons (1H LF NMR). The results indicate that in-package plasma treatment could be employed as an effective treatment for reducing spoilage bacteria in fish.