Indirect plasma treatment of fresh pork: Decontamination efficiency and effects on quality attributes

Atmospheric pressure plasma can facilitate microbiological inactivation while maintaining the product quality due to low temperature operation. Indirect plasma treatment offers new perspectives for large scale application. The aim of this study was to determine the impact of indirect plasma treatment on quality (color, pH, fluorescence, and reflectance) and safety (aerobic viable count) of porcine musculus longissimus dorsi (MLD). A microwave plasma setup (2.45 GHz, 1.2 kW; process gas air) was used for indirect plasma treatment of fresh porcine MLD with exposure times of 2 × 2.5 or 5 × 2 min. After plasma treatment the aerobic viable count of MLD remained between 102 and 103 CFU/g during the storage period of 20 days at 5 °C. Color measurements showed increased a values and decreased b values of pork meat after plasma treatment in comparison to untreated meat samples. The measurements of reflectance and fluorescence showed distinct differences between the treatments. This study shows the potential of indirect plasma treatment to decontaminate fresh pork but quality changes must be taken into consideration. Improved plasma process design is required to obtain significant microbial reduction without affecting the product quality and to guarantee consumer's acceptance.Industrial relevance text: Microbiological safety is an important issue in the meat industry. Especially meat quality should not be affected by the applied inactivation treatments so that gentle inactivation procedures are required. Indirect atmospheric pressure plasma treatment can facilitate microbiological inactivation and has the potential of large scale operation.

► Indirect plasma treatment kept total viable count of porcine MLD at 102 CFU/g during storage at 5 °C.
► The impact on product quality can be kept at a reasonable level using appropriate plasma sources.
► The shelf life of MLD is prolonged regarding the microbiological contamination.