Study On Screening And Preservation Effect Of Preservatives For Litchi

Fresh litchi(Litchi chinensis Sonn.)is a rare fruit of subtropical subtropical litchi,known as the ’Lingnan good fruit’.However,because litchi matures in the midsummer of high temperature and high humidity,coupled with its special fruit structure and physiological characteristics,browning and decay are very easy to occur after harvest.In this paper,Litchi fruits(Litchi chinensis Sonn.cv.Guiwei),cv.Feizixiao and cv.Huaizhi were used as materials to study ’Sportak’,’Sportak and KA’,and ’Sportak and BR’ respectively.The effect of ’Sportak and KA’,and ’Sportak and BR’ on the fresh-keeping effect of Litchi and its possible mechanism,and then screening through the orthogonal experimental design scheme can effectively reduce the litchi skin brown Modified and decomposed preservative formulations;Determination of nutrient quality indicators,peel browning index,chroma,anthocyanin content,proline content,relative conductivity,p H value,and peroxidase(POD)during storage in different treatments,Changes in laccase(Lac)and chitinase(CHI)activity.The results of the study are as follows:1.Compared with the control(CK)and the ’Sportak’ treatment,the ’Sportak and KA’ and ’Sportak and BR’ treatment significantly delayed the increase of peel browning index,maintaining a higher chroma L*,a*,C* and anthocyanin content;delayed the titratable acidity(TA)of pulp and The decrease of vitamin C(Vc)content had no significant effect on the change of soluble solids(TSS)content;delayed fruit weight loss rate and increase of proline content,relative conductivity and p H value of pericarp;increased activity of POD and Lac,but had no obvious effect on CHI activity.2.Compared with CK and ’Spolk’ treatment,’Sportak and BR’ treatment significantly delayed the increase of browning index of litchi pericarp,maintaining higher chroma L*,a*,C* value and anthocyanin Content;inhibited the decrease of TA and Vc in pulp,and had no significant effect on the content of TSS;delayed fruit weight loss rate and increase of proline content,relative conductivity and p H value of pericarp;increased activity of POD,Lac,and CHI.3.Under normal temperature storage condition,the anti-browning effect of ’Sportak and KA’ treatment is better than that of ’Sportak and BR’ treatment;under the condition of low-temperature storage,the anti-brown effect of ’Sportak and BR’ treatment is better than that of ’Sportak and KA’ deal with.4.The anti-browning effects of ’Sportak and KA’ and ’Sportak and BR’ treatments have certain differences in different lychee varieties.In general,the two treatments are ’Huaizhi’ better than ’Feizixiao’ in delaying the browning effect litchi.5.Through the visual analysis and variance analysis of the orthogonal test,it can be concluded that the best litchi preservation formula in this experiment is 500 mg/L Sportak,0.75% KA,0.20% biocontrol 1 and 50 μmol/L BR.Studies have shown that ’Sportak and KA’ and ’Sportak and BR’ treatment can significantly inhibit the browning of litchi skin,and can maintain a higher flavor quality,and extend the shelf life of the fruit.