Effect Of Wax-combined Technology On The Post-harvest Preservation Properties Of Lotus Root

Lotus root is the hypertrophic underground stem of the lotus plant,and it is an important export aquatic vegetable in China.The pulp of lotus root with good quality is white and fresh,tender and delicious,which has rich nutritional value.However,it is not easy to store lotus root after harvest,and it is easy to Browning,blackening and even decaying,which directly affects the sensory quality of lotus root and leads to the loss of nutrients,which has become one of the important factors affecting the export of lotus root.At present,there are many researches on fresh-keeping of lotus root at home and abroad,and some achievements have been made.In this paper,the effects of wax treatment combined with calcium chloride,hydrogen peroxide and vacuum packaging on the fresh-keeping effect of lotus root were studied.The biochemical indexes in the storage process of lotus root were detected.The specific experimental results were as follows:1.The effect of wax treatment combined with calcium chloride and hydrogen peroxide on the fresh-keeping effect of lotus rootUse concentration respectively 10%,15%,20%,25% and 30% of paraffin wax coating processing of lotus root,at room temperature(25 ℃)storage 29 days,respectively,on day 1,day 8,15 days,22 and 29 days weightlessness rate of lotus root,whiteness and Vc content,total number of colonies,soluble protein and soluble solids.By the experiment result,the different level of experimental group can improve the quality of lotus root of preservation,and can significantly reduce the weightlessness rate of lotus root,can effectively inhibit Browning and the total number of colonies of lotus root growth,also can effectively reduce the rate of inhibition of Vc content and soluble protein,the concentration of 15% of paraffin wax treatment effect is better,after processing of lotus root with better storage quality.Lotus root was soaked with 2% calcium chloride solution and 3% hydrogen peroxide solution for 10 minutes,and then coated with 15% paraffin wax.Through the detection of various biochemical indexes,it was found that the storage quality of lotus root treated by soaking and waxing was not as good as that of lotus root treated with wax alone.2.Study on the effect of carnauba wax and shellac on the fresh-keeping effect of lotus rootThe standard lotus root(uniform in size,strong in junction,no obvious mechanical damage)was coated with carnauba wax and shellac of different concentrations,and stored at room temperature(25 ℃).A series of biochemical indexes were detected on day 1,day 8,day 15,day 22 and day 29,respectively.The results showed that carnauba wax and shellac of 5% and 6% could affect the fresh-keeping effect of lotus root.Have different degrees of inhibition of the lotus root weightlessness rate increases,the inhibition of polyphenol oxidase(PPO)and peroxidase(POD)activity,thus inhibiting Browning of lotus root,can also inhibit Vc content lower rate,soluble protein denaturation and the rise of hydrolysis rate and the total number of colonies,in lotus root enzyme(PAL)activity of phenylalanine ammonia solution can have certain effect to improve.With 10%,15% and 20% of the carnauba wax effect is best;After the storage time of 25% and 30% of caraway wax treated lotus root reaches 15 days,the wax film will slowly break and fall off,which will lose its protective effect on lotus root,resulting in the rapid quality decline of lotus root in the later period.The shellac of 2% to 4% had little effect on the fresh-keeping effect of lotus root,while the shellac of 5% and 6% had an effect on the fresh-keeping effect of lotus root in the early stage of shellac treatment,but it was not as significant as that of carnauba wax in the experimental group,and the indexes were similar to those of the control group after 29 days of storage.3.The effect of wax treatment combined with vacuum packaging on the fresh-keeping effect of lotus rootLotus root without obvious damage was selected and divided into 5 groups.One group was treated as a blank control,and another group was vacuumed.The remaining 3 groups were all coated with 10% carnauba wax,and after the wax solution was slightly dried,one group was not treated,one group was vacuumed,and one group was wrapped in plastic wrap.Finally,the five groups of lotus root were CK,vacuum package,wax treatment,wax treatment + vacuum package and wax treatment + plastic wrap package.Through the detection of various biochemical indexes,it was found that in the storage process,the fresh-keeping quality of the treated experimental group was significantly better than that of the control group,among which the wax treatment and vacuum packaging combined treatment had the best effect on the fresh-keeping of lotus root.At the 29 th day of storage,the changes of biochemical indexes were not significant,which could significantly inhibit the activity of PPO.At the end of storage,the indexes of lotus root were not significantly different from those of lotus root at the beginning of storage.This means that this method can extend the shelf life of lotus root to about one month at least.