Studies On Drying Technology, Quality And Storage Characteristics Of Jinhua Ham Slices

Jinhua ham is the unique traditional food of China, but hard texture, difficult storage condition, vaporific flavor substance, complex processing and salty taste restricted the development of Jinhua ham industry. In terms of the circumstance, this study aims at studying on new Jinhua ham’s convenience products, to meet the need of the contemporary society. The results were as follows:After studied the effect of different drying methods on the properties of dried Jinhua ham slices, it was found that in terms of color changes rates, hot air drying was better than freeze drying than vacuum drying. As to the rehydration characters, freeze drying was better than hot air drying than vacuum drying. For property characters, hot air drying was better than vacuum drying than freeze drying. In the case of the nutritional value, freeze drying was better than vacuum drying than hot air drying. In terms of flavor compounds, vacuum dried products had more kinds of volatile compounds and hot air drying had more compounds which had much more contribution to characterize volatile compounds and freeze drying had the best effect of containment and enhancement.Using vacuum drying method to process dried Jinhua ham slices, after studied the vacuum drying characters of different temperatures from60℃to90℃and fit through11kinds of mathematic models, the results showed that Modified Henderson and Pabis model was the best mathematic model to describe vacuum drying characters of Jinhua ham slices, which had the highest R2and the lowestX2and RMSE. After calculated Deff, Ea was calculated as34.59kJ/mol. By low frequency magnetic resonance technique, the results showed that at the beginning of drying period, the water tended to strengthen the combine ability to the sample, at the end of drying period, the water tended to weaken the combine ability to the sample.After the drying process, the fat’s degree of oxidation was significantly increased. By spraying anti-oxidations on the samples to prevent the degree of oxidation, a comprehensive assess method was invented. The single factor experiment’s results showed that the best concentration of rosemary extractions is0.04%, VE is0.05%, TBHQ is0.03%. To get the better result, D-optimal mixture design was made, and the software given the best formula was0.019%rosemary extractions and0.031%VE. A regression model was made and the expression was: R=-42729.04X1-49545.39X2-80209.65X3+2.17E-004X4+634.14X1X2+427.60X1X4+470.42X2X3+495.86X2X4+803.36X3X4。 A3-layer BP neural model was made to exam the anti-oxidation effect, the model could imitate the anti-oxidation effect and predict the anti-oxidation index highly accurately, which indicate the model had highly applications.The absorption isotherms and desorption isotherms were made and fit with6kinds of mathematic models. The result showed that Modified Halsey model was the best model to describe the absorption characters of vacuum dried Jinhua ham slices and the Modified GAB model was good to describe the desorption characters of vacuum dried Jinhua ham slices.Using POV value as the index, and regress by first-order kinetics and Arrhenius equation, the model of packaging of vacuum dried Jinhua ham slices was made. The model predict that by using deoxidation and vacuum packaging could extend the expiry date to longer than6months, which made it possible to be commercial.