Study On The Optimization Of Fresh Beef Process And Its Quality Control Of Plasma Active Water

Beef has the characteristics of high protein and low fat,which is deeply liked by the people.However,the high nutrition and high water activity of fresh beef are very suitable for the growth and reproduction of microorganisms,and it is easy to spoil meat due to the infection of spoilage bacteria in the processing,storage,transportation and the process.Plasma,as a new non-thermal physical sterilization technology,reacts with water to produce PlasmaActivated Water(PAW)with a broad spectrum of sterilization characteristics,and at the same time,high efficiency,rapid and safe characteristics make it gradually applied to the field of food sterilization and preservation.In this paper,fresh beef was taken as the research object,and PAW production and processing technology were optimized through steepest climbing experiment and response surface experiment,and the effects of PAW treatment on the bacteria phase and growth kinetics of fresh beef during storage as well as beef quality were analyzed.The main research results were as follows:1)The preparation and treatment of fresh beef of PAW were optimized.It was found that operating voltage,working time,air flow rate,processing capacity,immersion time,immersion temperature and material ratio all had effects on sensory score.Further,Plackett-Burman test confirmed that the significant parameters were operating voltage,working time and immersion time.Finally,through the steepest climbing experiment and response surface experiment and combining with the actual situation of the equipment,the optimal processing parameters of PAW for treating fresh beef were optimized as following:working voltage 5kV,working time 5 min,air flow rate 9 L·min-1,processing capacity 1000 mL,soaking temperature 4℃,material ratio 10:1.Under these conditions,the sensory score of beef reached 9.3.2)The changes of bacteria phase and growth kinetics of beef treated with PAW during storage were studied.PAW treatment can significantly inhibit the growth rate of microorganisms.Pseudomonas and acid bacteria were the dominant bacteria in the control group(water treatment)and the PAW group at the later stage of storage,respectively.Kinetic analysis showed that PAW could effectively kill Enterobacter in raw meat and change the delay duration and maximum growth rate of Pseudomonas and Brochothrix thermosphacta.Meanwhile,PAW treatment significantly reduced the number of Lactic acid bacteria and Micrococcus at the later stage of storage,indicating that PAW has different ways of acting on different bacteria,and can significantly inhibit the growth and reproduction of microorganisms during the storage of fresh beef.3)The quality changes of fresh beef treated with PAW were analyzed.Compared with water treatment group,PAW treatment had no significant effects on L*,a*,b*,Hue Angle and Chroma value of beef.However,the total color difference value of the PAW treatment group and the water treatment group is greater than 0.5,and the content of metmyoglobin under PAW treatment is significantly increased.Meanwhile,compared with the control group,the drip loss and shearing force of beef under PAW treatment are significantly increased,and the meat remains relatively stable during storage.PAW treatment significantly reduced the content of total volatile base nitrogen in beef during storage,meanwhile,PAW treatment increased the lipid oxidation level,and the thiobarbituric acid value in PAW treatment group was significantly higher than that in water treatment group.