Research And Development Of SO₂Release Preservative Application In The Low Temperature

Three different membrane materials and preservative raw materials，release agent werestudied to prepared SO₂slow release preservative. Two kinds of SO₂preservatives in differentratio of raw materials were got by the storage of Kyoho grapes and Red Globe grapes.（1） The air permeability of three kinds of film：non-woven membrane materials> deoxidizerfilm material> paper composite film material. The paper composite membrane has the bestability to control of the release rate of SO₂，and the non-woven composite membrane has themost emission of SO₂，but difficult to control.（2） The study on paper film composite membrane material to prepare SO₂slow releasepreservative by different primary materials and release agents show that A1is the mainstrength SO₂release material， the rapid formation of the desired inhibition of microbialconcentration of SO₂，but the outbreak of a short time，persistent poor，A2component-basedextended release material preparation SO₂preservative quick release stage reached about30d，the overall SO₂release process of SO₂emission stability， long duration.A1，A2raw mixcomponent complement deficiencies each other， both to better control of SO₂emissions，butalso to extend the release time of SO₂， the properties of SO₂release the preservativeproduct is more stable，therefore，the choice of the host material to A1， A2is preferablymixed component selection.（3） The maximum of SO₂release of EVA and paraffin-embedded preservative is8μg/ml inthe fast phase， and it is lower than the case without embedding preservative. The release rateof SO₂release maintain stable，and the sustainable release time continued to55d，but the costis higher than not embedded preservative.（4） The effects of different preservatives on Kyoho grapes and Red Globe grapes werestudied by a regular measurement about basis weight loss rate， decay rate，the rate of grainout， good fruit rate of grapes at low temperature （2℃⁴℃） storage. Different ratios of A1and A2were needed in the case of the same storage conditions to ensure optimal preservationto store Kyoho grapes and Red Globe grapes：Kyoho grapes，1：2¹：5，and Red Globegrapes，1：1¹：2.The final design of SO₂slow release preservative was determined in our study. Double release structure were used，and BOPP film for barrier layer，E1paper composite membranefor slow release layer，E2paper composite membrane for rapid release layer，and A1and A2for raw material mixture（the specific ratio of A1and A2according to the different types ofgrapes），B2for release agent，and moisture absorption agent C and other inert ingredientswere added. The product can be used to preserve the grape，and it can release the necessaryconcentration of SO₂to inhibit microbial growth and respiration of grape.The residual amount of SO₂of grape storage50d by SO₂slow release preservative waslower than the limit of controlling standards，and will not cause harm to humans，so thepreservative studied is a safe grape preservative.