Effect Of Lactic Acid Combined With Calcium Chloride Treatment On Fresh-Cut Lotus Root

Fresh-cut overcomed the shortcomings and defects in ordinary lotus root with mud during processing and preservation.Fresh cut lotus root is popular with crowded because of its fresh convenience and safety Lotus root is an aquatic plant with high water content and extremely thin epidermis,which is very vulnerable.It is prone to be browning and wilting during storage and processing,which seriously affects the development of fresh-cut lotus root.Therefore,to maintain the quality of fresh-cut lotus root,it is pretty important to suppress the Browning.1.Response surface method(RSM)was used to establish a response surface model of the influence of different concentration of lactic acid(0.3-1.0%),different concentration of calcium chloride(1-3%)and different soaking time(5-15 min)on the weight loss rate,hardness,L value and Browning degree of the fresh cut lotus root.All four models are available,with a high degree of responcing and with small errors.The interaction of lactic acid concentration,calcium chloride concentration and soaking time on the Browning of fresh-cut lotus root was analyzed,and the conditions for inhibiting the Browning were optimized:CaCl2 concentration 2.0%,lactic acid concentration 0.7%,and soaking time 10min.The verification test showed that this treatment could reduce the Browning degree of fresh-cut lotus root stored at 4℃ for 8d and maintain a good quality.2.Compared with the single treatment group,0.7%lactic acid combined with 2.0%calcium chloride group inhibited the increase of browning degree and the decrease of brightness of fresh-cut lotus root effectively.The firmness and ascorbic acid content are at a high level.The compound treatment repress the rise of MDA,maintained a high level of CAT,SOD and APX activities.The DPPH radical scavenging capacity was improved and the accumulation of H2O2 and O2-was reduced,thereby protecting the cell membrane system,and avoiding the imbalance of reactive oxygen metabolism.The PAL,POD and PPO activities of the composite treatment group were significantly lower than those of the CK group.PAL can catalyze phenylalanine to trans-cinnamic acid,and then through a series of reactions to produce a variety of phenolic substances.At the same time,PPO and POD can catalyze the reaction of phenolic substances and oxygen to eventually produce brown substances.It was proved that the compound treatment could control the total phenolic content by inhibiting PAL activity.By inhibiting the increase of PPO and POD activity,the process of converting phenolic substances into quinones and then into brown substances was restrained,and finally the generation of Browning degree could be effectively suppressed.