Study On The Effect Of Composite Coating Of Chitosan/Nano-SiOx Treatment On Huangguan Pear Preservation

Huangguan pear has good quality, strong resistance, early-bearing, high yield in successive years and good adaptability. But it does not have a long storage life, so it is necessary to find a method that can extend the storage stage as well as keep fruit quality. There have been some reports about the application of chitosan on preservation fruits and vegetables including apple and strawberry. In this test, we made a preservative coating with chitosan modified by Nano-SiO_x as the main ingredient, and added other different assistant ingredient, and then determine the mechanical properties and antimicrobial. Chemical and physiological characteristics of Huangguan pear after the coating were mesured, aiming to get the mechanism and the optimal method of coating preservation on Huangguan pear storage.The results are showed as follows:1. Through the test, we got the best composition of the film of chitosan, acetic acid, 1,2 - propanediol, nano-SiO_x, Tween 20 and PVA, and dried it with the wind speed 3m/s, temperature 40℃.2. Through the orthogonal experiment, the decay rate and the weight loss rate after storaged 60 days as the evaluation of index, the best coating formation was got, which was 1.5% chitosan, 1.0% acetic acid, 3% 1,2-propanediol, 0.01%TW20, 1.0% PVA. The experiments showed that this chitosan coating was effective in freshing Huangguan pear, the healthy fruit was above 85% for 60 days storage, and extended the storage period significantly.3. The coating with Chitosan and nano-SiO_x could significantly reduce the Huangguan pear decay rate and weight loss, significantly increase the fruit firmness during the storage, delay the decreasing of titratable acid, soluble solids content and total sugar, and prolong the storage time.4. The result suggested that Chitosan coating could delay the reduction of cell membrane permeability, reduce the cell membrane structural damage and help to the storage of Huangguan pear.5. The composite coating on Huangguan pear not only could effectively reduce the incidence of jizhua disease, but the effect was better than refrigeration.