Preliminary Study On Effect Of Electrolyzed Oxidizing Water On Prevetion Of Chinese Yam (Dioscoreaceae) Enzymatic Browning

More and more attentions are paid to the inhibition of microorganisms by the EOW in recent years, resulting from its many advantages such as the broad-spectrum bactericidal activity with high efficiency, economy, safety and eco-friendliness. Now, the research of StAEW, SAEW and NEW applications on the field of agriculture and food still gain great attentions. With the development of the research, some interesting problems including the synergistic effect of EOW and many other processing methods on the inhibition of microorganisms, the germicidal ingredients and the mechanism of EOW (available cholorine, ORP, reactive oxygen species), the control of fruits and vegetables enzymatic browning by using EOW, and so on have been explored deeply. As a non-thermal method in the food industry, EOW is of great potential to be developed.Chinese yam is rich in essential amino acids and dietary minerals, and it is widely used in both medicine and food in China. The resources of Chinese yam cultivars are rich, e.g., ’Tie Gun’,’Ma’,’Jiu Jinhuang’. After investigation, the yield of the yam (Jiu Jinhuang) as well as the sales of of the yam (Jiu Jinhuang) are large in Tai’an city’s supermarkets and markets. Enzymatic browning often occurs during fresh-cut yam processing, which impairs the quality and market value of Chinese yam product, so the deep study on the Chinese yam enzymatic browning control technique could provide theoretical and practical significance for promoting the Chinese yam processing technology, improving the Chinese yam product quality and extending its shelf life. In this paper,’Jiu Jinhuang’is used as raw materials, the effect on the prevention of Chinese yam enzymatic browning and the antibrowning technology optimization of fresh-cut Chinese yam using SAEW were investigated, the main results and conclusions showed that:The effect of EOW with different physicochemical parameters on the browning related physiological indexes:EOW was used successfully for reducing browning degree of ’Jiu Jinhuang’Chinese yam with higher L*, h* values and lower a* value during storage time. Besides, the L* value of the Chinese yam treated with NEW was the highest and the a* value of the Chinese yam treated with SAEW was the lowest at 72 h, indicating that these two groups had the least amounts of browning. It was found that the EOW treatment delayed Chinese yam browning with inhibiting activities of the PPO, POD and PAL at 24 h. The SAEW as the browning inhibitor had the best effect. The group treated with SAEW had the strongest antioxidative activity with the highest flavonoid, lowest MDA content and stronger DPPH radical scavenging ability (than TW-treated group) during the storage. The contents of the phenolic acids including gallic acid and chlorogenic acid in the group treated with the SAEW were higher than those treated with TW and the NEW. The aerobic plate count of SAEW treatment group was much lower than that of TW treatment group. In addition, the SAEW-treated group could keep the highest polysaccharide content, at the same time, the decrease of the TSS treated with the CA was the lowest.The extraction process, isoenzyme and enzyme kinetics of PPO: The extraction process of Chinese yam crude PPO enzyme was optimized through single factor experiments and orthogonal experiments. It was also found the proper saturation point for the ammonium sulphate precipitation was 40%. And the PPO activity was 561.759 U/mg. Besides, the nearly unchanged samples’ PPO isoforms treated with EOW were confirmed by Native PAGE. It was found that the reaction between the PPO extracted from the yams and catechol belongs to the Michaelis-Menten through the analysis of enzyme kinetics of PPO. The EOW’s inhibition effect on the PPO activity was better than that of CA.Study on antibrowning technology of fresh-cut yam:Through single factor experiments and central composite design focused on the soaking time and solution temperature, the optimal treatment time (17.65 min) and temperature (13.45℃) for the prevetion of fresh-cut Chinese yam’s enzymatic browning using SAEW were gained. And the browning degree was 0.211 at 4℃ after 2 day’s storage.