Studies On The Cloud Stabilization And Safety Of Cloudy Apple Juice

In nowdays, the limition of the development and export of Cloudy apple juice is due tothe poor turbidity stability and the exceed of pesticide residues in our country. The addition ofthe suitable stabilizer was principal form to improve the turbidity stability of the juice. Withthe gradual increasement of the health consciousness, the products with stabilizer are rejectedby the consumer. Therefor, the zero addition juice has been the new development trend in thefood industry. What’s more, the exceed of pestcide residues, especially the organophosphoruspesticides, are harmful to the health of our consumers, and always induce to the blockedexports, large-scale returm and compensations. This result is not only the wasted resources inour country, but also couse an adverse effect in the world.Because of these reasons, this project was going to study how to improve the cloudystability without the stabilizer and exogenous enzyme. In this study, we used multiple methodto improve the cloudy stability, including selected different kinds of apple, adapted thestorgeconditions of the apple and the juice process, and utilized the apple exogenous enzymesto change the content and the properties of pectin, which is the main factor in the cloudystability. The improvement of the juice sercurity was mainly through the heat treatment,which could control the numble of the microorganism and the quality of the juice. What’smore, we employed the ultrasonic wave and irradiation technology to degrade the residues ofOrganophosphorus pesticide, and examine the effects on the quality of the juice. Thefollowing were the principal findings.First of all, four kinds of apple were used to prepare the juice, and the cloudy stability,from high to low, were yellow banana, flower cattle, Lingbao and crystal fuji. While thesekinds of apple has the different maturationperiod and preservation period, we can selectivelychoose the apple to prepare the juice. Then we found that the turbidity retention and stabilitywere improved with the extension of the time when the apple were store in4℃(lowtemperature) and12℃±1℃（room temperature）.And the room temperature storage was moresuitable to improve the turbidity and cloudy stability of the juice, compare with the lowtemperature storage.Second, we stduied the effects of the heat treatment on the quality of juice. The totlenumble of the bacteria were lower that the national standard when the apple were treated5min at90℃. mold and yeast couldn’t be detectedwhen the temperature is higher than90℃.The total phenolic content were decreased in heat treatment, and the color of the juice wasaffected by the decreasement of the total phenolic. In this study, we found that the juice hadthe lowest turbidity retention rate at70℃heat treatment, and the decreasement of theturbidity retention rate was following the extension of the heat treatment time. We adopted theheat treatment at front and rear apple broken, and we found that the heat treatment time afterbroken is longer, the stability is better. The turbidity and cloudy stability of juice were also affected by the broken temperature. Compare with the room temperature broken, the turbidityand cloudy stability of juice were much better in40℃broken.Finally, we took the research on the degradation of the Organophosphorus pesticides byultrasonic wave and irradiation technology. With the increasement of the ultrasonic power andthe extent of the ultrasonic time, the degradation rate of dichlorvos, acephate, dimethoate andchlorpyrifos were also incresed. Dichlorvos had the highest degradation rate, and thefollowing were acephate, dimethoate and chlorpyrifos. These pesticides could be maximumdragraded at the ultrasonic power was600w and the treated time was120min. Irradiationtreatment can also reduce the content of these pesticides. The degradation rate from high tolow were chlorpyrifos, dichlorvos,acephate and dimethoate. The degradation rate of thepesticides were increased with the increase of irradiation dose. Compared with ultrasonictreatment, irradiation treatment could be more effective to degrade the organophosphoruspesticide in apple juice, and the quality of the juice couldn’t be affected. While the ultrasonictreatment can effectively improve the turbidity and turbidity retention rate of apple juice,these were helpful to improve the cloudy stability in the juice.