Effect of Plasma-activated Water as Thawing Media on the Sterilization and Quality of Beef

Objective: Evaluating the effects of plasma-activated water (PAW) used as a thawing medium on the microbial safety and fresh quality of beef. Methods: The PAW was prepared by treating the 300 mL deionized water with the plasma jet for various times (40, 60, 80, 100, 120 s). Using the PAW, which was placed at room temperature (25 ℃) to thaw the frozen beef tendon meat for 10 min, and the mass ratio of PAW to beef was 4:1. The beef’s and the thawing media’s physicochemical properties such as the total number of colonies, nitrite, and pH were assessed, and water retention (purge loss, water holding capacity), lipid oxidation, and protein loss of beef were evaluated. Results: As the preparation time of plasma-activated water prolonged, the antibacterial activity of PAW significantly increased (P<0.05), and the number of total viable bacteria in beef after thawing treatment was reduced by 0.91 lg (CFU/g). PAW treatment significantly enhanced the water holding capacity of beef (P<0.05). After thawing, the juice leakage, lipid oxidation and protein loss were reduced by 1.83%, 0.0944 mg/kg and 0.085 mg/mL, respectively. After thawing, the maximum content of nitrite content in beef was 3.38 mg/kg, which was still lower than the limit of quantification, while the pH value of thawed meat only increased by 0.06. The results showed that such a treatment had no significant effect on the nitrite content and pH of beef (P<0.05). This study would provide a theoretical basis and data reference for the application of PAW in the thawing of frozen meat products.