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Abstract
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Pseudomonas tolaasii and Lecanicillium fungicola are the bacterial and fungal pathogen that causes brown spots and dry bubble diseases and spoilage of fresh mushroom. The objective of this study was to consider the efficacy of plasma-activated water (PAW) on the inactivation of P. tolaasii and L. fungicola and storage quality of button mushroom. Button mushrooms were immersed for 10 min in PAW generated by four types of plasma feeding gas at activation times 5, 10, 15, and 20 min, designated PAW-5, PAW-10, PAW-15, and PAW-20, respectively. The results indicated that the bacteria and fungi growth was controlled by PAW treatment through 21 days of post-harvest storage. The lowest bacterial and fungal population was 3.6-log CFU g1 and 4.7-log CFU g1 after treatment with PAW-20 generated by hydrogen peroxide bubbled with air (H2O2-air), which was significantly lower than that of control (6.57 and 7.49 log CFU g1) or soaking in distilled water (7.65 and 8.57 log CFU g1), respectively. The plasma created by H2O2-air gas formed the highest concentration of H2O2, NO2, and NO3 species in PAW. The findings of water friendship and firmness showed that immersion in PAW could delay the softness of the mushroom. In addition, treatment with PAW significantly inactivated polyphenol oxidase (PPO) and peroxidase (POD) enzymes. Meanwhile, significant changes were registered in the color, antioxidant activity and phenolic content of mushrooms treated with PAW and the control groups. Thus, PAW treatment may be considered as an alternative method for fresh keeping of button mushroom
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