Preparation Of A New Type Antioxidant Fresh-keeping Agent For Fruit And Vegetable

When fruit and vegetable are harvested for doat and microbe's infraction ,their store is difficulty.To manufacture a new type of antioxidant Fresh-keeping agent for fruit and vegetable has important practice meaning.Ferulic acid and it's ramification have favorable antioxidant ability, so we synthesize two ferulic acid ester with ferulic acid as a mostly raw material and observe their antioxidant ability.Then the two ester were compounded with other matter to form a new antioxidant fresh-keeping agent.Synthesis of glucose ferulic acid esters is made by alcoholysis ester exchange technique, this technique including two stepsr.firstly, synthesized ethyl ferulate;secondly, ethyl ferulate reacted with glucose to create glucose ferulic acid esters by ester exchange .and synthed xylose ferulic acid esters using this similar technique.The optimum synthesis condition of ethyl ferulate which screened out by orthogonal experiment : (1)the ratio of ethanol/ferulic acid is 6:1, (2)the reaction time is 8 hours, (3)the dosage of catalyzer is ferulic acid's 12%. The production is counteracted by sodium carbonate ,then use thermal saturation salt water solution to wash the production until water layer is clear ,next extracted the layer 3 time with aether, the accepted purification is recrystalized by n-hexane ,we can accept purified white solid.Synthesis of glucose ferulic acid esters is using alcoholysis ester exchange technique which cetyl trimethyl ammoniumbromide (CTAB) acts as a phase-transfercata-lyst,oleic acid acts as dispersant ,the dosage of CTAB is 0.8 (w/w) , the dosage of dispersant(oleic acid) is 0.4 (w/w) ,the temperature is 90℃.We get the optimum synthesis condition of glucose ferulic acid esters which screened out by orthogonal experiment is as follows: (1)the degree of vacuum is 0.08Mpa ,(2)the dosage of catalyzer (K2CO3) is 0.6 (w/w) ,(3)the ratio of Glucose/ ethyl ferulate is 2: l,?the reaction time is 6 hours . The production is washed by 95% ethanol ,we can get delamination, then using butanone to extract the lower layer ,the purificatory glucose ferulic acid esters can be accepted.The synthetical glucose ferulic acid esters and xylose ferulic acid esters have preferably antioxidant Fresh-keeping effect to picked HFS.apple.by comparing the apples processed by ester with the apples which are not processed, we find that the LOX( lipoxygenase) activity and ethylene release of apples processed are lower than these apples which are not processed.and the Antioxidant effect of glucose ferulic acid esters is better than xylose ferulic acid esters.We compound glucose ferulic acid esters with xylose ferulic acid esters by different proportion.to observe the effect of restraining LOX of these ratio and find out the optimum ratio.We find the effect is best when the ratio of glucose ferulic acid esters/ xylose ferulic acid esters is 4/1.Preparation of Prescription for Fresh-keeping agentglucose ferulic acid esters compound with xylose ferulic acid esters 4/1 act as antioxidant,Borax act as Preservative ,ascorbic acid act as (antioxidant) synergistic reagent, D, L-tartaric act as (Preservative) synergistic reagent, the deionized-water act as solvent. The ptimum ratio of Antioxidant effect is gotten by orthogonal experiment,the best Prescription is as follows:Proportion 4/1 of glucose ferulic acid esters and xylose ferulic acid esters's share islO,borax's share is 12, wate's share is 1000, ascorbic acid's share is 3 .