等离子体活化水作为解冻介质对牛肉杀菌效能及品质的影响

目的:研究低温等离子体活化水（plasma-activated water，PAW）作为解冻介质对牛肉微生物安全及生鲜品质的影响。方法:采用射频等离子体发生装置，处理水量为300 mL，以高压电源处理时间（40、60、80、100、120 s）为试验因素，制备不同处理时长的PAW。将放置至常温（25 ℃）的PAW作为冷冻牛腱子肉的解冻介质，以介质与样品4:1的质量比例静置浸泡解冻10 min，测定牛肉和解冻介质中的菌落总数、亚硝酸根含量、pH，及牛肉保水性（汁液损失率、持水力）、脂质氧化和蛋白质流失状况。结果:随着等离子体活化水制备时间的延长，其减菌效果显著增强（P<0.05），解冻后牛肉中的菌落总数可降低0.91 lg (CFU/g)。将等离子体活化水作为解冻介质可显著增强牛肉的持水力（P<0.05），汁液损失率最多可降低1.83%，脂质氧化程度可降低0.0944 mg/kg，蛋白流失可减少0.085 mg/mL，牛肉经解冻后，亚硝酸根含量最高为3.38 mg/kg，仍小于定量限，解冻后肉品pH最大仅增加0.06，即该解冻方式并不会对牛肉的亚硝酸根、pH产生显著影响（P<0.05）。本研究为低温等离子体活化水在肉制品解冻方面的应用提供了一定的理论依据和数据参考。

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.