Effect Of Electrolyzed Functional Water-ultrasonic Washing On Safety Quality And Enzymatic Browning Of Fresh-cut Potato

To ensure the quality and safety is the lifeline of the development of fresh-cut potatoes industry.The main factors affecting the quality of freshcut potatoes are excess pesticide remains,microbial pollution and enzymatic browning.Washing process is one of the most important processes that affect the quality of fresh-cut vegetables,so it is very important to select the suitable washing methods and conditions.Electrolyzed functional water(EFW)combined with ultrasonic washing technology is a new washing method,which has not been deeply explored in controlling pesticide residues,microbial pollution and enzymatic browning.In this study,the effects of different washing solutions,sample-towashing solution ratio,ultrasonic power and washing time on the removal of pesticide residues,delaying enzymatic browning and inhibiting microbial growth were investigated.The mixed liquids of procymidone,phorate,chlorothalonil and chlorpyrifos were used to contaminate in the fresh-cut potatoes cut in different ways.And the pesticide residues were detected by gas chromatography-mass spectrometry(GC-MS).The removal rates of four kinds of pesticide residues were obtained after different washing treatments;The browning degree of potatoes was measured by extinction value method at 0,2,4,6,8 and 10 days after washing.The total bacterial counts and the colonies of Escherichia coli,Salmonella and Staphylococcus aureus were counted by dilution plate counting method.The results showed that:(1)Ac EW was suitable for removing pesticide residues,delaying enzymatic browning and inhibiting microbial growth.(2)There was no significant difference in the effect of pesticide residues removal and delaying enzymatic browning under different sample-towashing solution ratio(p > 0.05),and the suitable ratio was 1:20.(3)The results showed that the suitable washing power of potato strip,potato chips potato slices and diced potato were 200,400,400 and 400 W respectively,and the suitable washing time was 10,10,20 and 20 min respectively.(4)The results showed that the effect of ultrasonic power and washing time for delaying enzymatic browning were different due to the different specific surface area of different cutting methods,and the effect on delaying enzymatic browning was significant(p< 0.05).(5)The suitable ultrasonic power for potato strip,potato chips potato slices and diced potato were respectively 200,300,200 and 400 W in different storage time.The browning degree were all the lowest when the washing time was 20,10,10 and 20 min respectively.(6)The discrepancy of specific surface area and microbial species in different cutting ways caused different inhibition effects on microbial growth under different washing conditions;ultrasonic power and washing time had little effect on the growth of Escherichia coli(E.coli)and Salmonella in different cutting ways,which may be related to E.coli and Salmonella.(7)The inhibition effect of potato strip,potato chips potato slices and diced potato on microbial growth were better when the sample-towashing solution ratio were 1:320,1:80,1:80 and 1:20 respectively;the inhibition effect were better when the ultrasonic power was 200,300,400 and 300 W,respectively;the inhibition effect were better when the washing time were 15,10,10 and 20 min,respectively.In this study,the effects of EFW combined with ultrasonic washing technology on the removal of pesticide residues,delaying enzymatic browning and inhibiting the growth of microorganisms in fresh-cut potatoes were obtained.On this basis,the appropriate conditions were also selected,which provided theoretical basis and technical support for the further research and promotion of EFW and ultrasonic washing technology in freshcut potatoes.