Study On Browning And Aging Control Technology Of Chestnut Kernel During Processing

Chestnut kernel with abundant nutrition and kinds of health function.But in our country,chestnut kernel browning and aging have been constrained the developing of chestnut kernel industry.So it is important to china's chestnut kernel industry that studied the measures to restrain chestnut browning and aging.In this study,four different areas of chestnut kernel which including Hebei,Shandong,Henan and Liaoning were used as material for selecting the most vulnerable species of browing and aging,while a series of measures including color-protecting,coating,soaking in food additives had adopted to control browning,ageing phenomena of chinese chestnut kernel when they were process.The contents and conclusion showed as following:1.Four kinds of different regins chestnut kernel were cooked in water at 100℃for different times and storaged for 3 d at room-temperature.The results showed that with the passage of cooking time and storage time became more and more longer,the browning of chestnut kernel became more serious.the degree of chestnut kernel browning between Shandong,Liaoning was not obvious;Compared with the other kinds,the degree browning of Qianxi's which the most vulnerable species of browing and Henan's chestnut kernel lower than the other regins significantly(P<0.01) during was cooked in water at 100℃,but when they were storaged for 3 d at room-temperature the degree of browning not ignificantly,The results showed that different varieties of chestnut kernel had the different capability of browning;2.The optimum concentration of chestnut kernel color-protecting were studied by the single-factor experiment and Qianxi's chestnut kernel was used as material firstly;Seeondly,the regression orthogonal design of a pilot program was set up between value△E and ascorbic acid,citric acid,phytic acid.The results showed that compared with the others,the function of citric acid was obvious,the best formula was ascorbic acid concentration of 0.3%,citric acid concentration of 0.4%,phytic acid concentration of 0.4 %.3.The color-protecting technology on cooked Qianxi's chestnut kernel was studied by using chitosan coating treatments.The result showed that compared with the chestnut kernel without the coating,the degree of browning,weight loss rate of chestnut kernel with the coating had a remarkable improvement.According to study,the best formula was chitosan concentration of 1.5%,acetic acid concentration of 1.0%,the gelatin concentration of 0.3%,the glycerine concentration of 0.4%,the monoglyceride of 0.06%.4.In this study,four different areas of the chestnut kernel were used as material to study the relationship between different gelatinization degrees,different storage time and the aging degree of chestnut kernel.The result showed that gelatinization more higher the degree of chestnut kernel aging more and more prone to less.When chestnut kernel were storaged before 12 h,the changes of chestnut kernel aging was serious,but with the extension of storage time,the speed gradually slows.The aging degree of chestnut kernel was measured after Liaoning's chestnut kernel was soaked in a certain concentration of monoglyceride,sucrose esters,cyclodextrins,xanthan gum,carrageenan,gelatin solution for 30 min and at 4℃for 24 h.Studies have shown that compared with the control when the monoglyceride,sucrose esters,xanthan gum,carrageenan,gelatin concentration reached of 0.04%,0.06%,0.075%,0.05%,0.075% respectively,have a better gelatinization;While compared with the other food additives when the concentration of cyclodextrins reached 0.60% have a better gelatinization.