Analysis Of Preservative Residue Dynamic Changes On Table Grape In Storage

Table grapes were well received by consumers, because of its delicious taste,nutrient-well and other excellent quality. But it is difficult to store the grape, for it can appear the phenomenon easily of threshing, rot, mildew and other phenomena during storage. The treatment of releasing SO2 slowly is the most effective preservative technology, but the fruit has the problem of bleaching injury. The healthy problems caused by the change of residues of preservative in grape fruits have caused the attention of people. Therefore, it is very important to resolve the change of SO2 residues in grape fruits and the problem of the pathway that fruits absorb SO2.Selecting 4 kinds of different grape varieties as test materials, the changes of SO2 residue content in grape fruits in the storage period and resistance of different grape varieties to preservative has been studied, and has studied preservative that has an effect on grape threshing rate and decay rate. The experiment has investigated the dynamic changes of SO2 in grape fruit. The Zhangjiakou Red Globe grapes were simulated and analyzed the change process of SO2 residues in fruits. It provides a theoretical basis for grape storage and the reasonable use of SO2 preservative. The main research results are as follows:During the whole storage period, using different SO2 preservative deal with the mare、muscat、kyoho、longan, the SO2 residues in grapes was: Treatment I>treatment II>treatment IV>treatment III>treatment V. The tolerance to SO2 preservative was different in grapes. The sequence of tolerance was: longan>Muscat>kyoho>mare. The sulfite residues of grapes were not exceed the FDA standard 10mg/kg.Different preservatives have different effects on the threshing rate and decay rate of grapes. Longan, Muscat grapes in the treatment I and II processing threshing rate and decay rate was low. In order to achieve a better preservation effect, it should be based on different varieties of grapes to select the appropriate preservative.The sulfite residues of different parts of grapes were variant greatly after fumigated with SO2, from high to low in cob, stalk, fruit peel, flesh and fruit seeds. Facts showed that cob,stalk was the main way of SO2 entrance into grape fruit. The mechanical injure of grapessurface can accelerate SO2 into the fruit.The sulfite residues of different parts of grape were changed during storage time after the grape was bleached by SO2 preservative. The phenomenon has been showed that the SO2 residues in grapes were migrated from pedicel to grape inword. The sulfite residues migration rate of different bleaching damage levels of fruit was different which was II class(Bleaching damage area20%~40%)>III class(bleaching damage area>50%)>I class(bleaching damage area<20%).