Study On Technology Of Liquid State And Low Cholesterol Lard

China is the pig farming country, with a huge of lard resources. With the continuous improvement of people's living standard and health awareness, lard as a traditional edible oil status has been weakened. Due to lard under the normal temperature is solid, is not conducive to food processing and production, how to make rational use of lard to become the topic which the majority of scholars increasingly research. This study to Ningxiang pig lard as research material, through dry fractionation technology to reduce the melting point of lard and based on using cholesterol cholesterol oxidase removal of lard, get Low cholesterol liquefied lard. The main research contents and results are as follows:1. With the cooling rate, the crystallization temperature and the crystallization time as the experimental factors, the experiment was conducted to study the First-step dry fractionation of Ningxiang pig fat, To make it at room temperature. A single factor experiment was carried to determine the cooling rate of the dry process:2-8 ?/h, crystallization temperature range of 22-26 ?, curing crystallization time 8-15 h. Through the orthogonal experiment, the optimum technological conditions for the extraction of dry fractionation are as follows:the cooling rate is 4?/h, the crystallization temperature is 26 ?, and the crystallization time is 15h. The average rate of liquid oil yield was 85.91%, and the melting point was 22.31 ?, which was liquid at room temperature, with the pig fat flavor and transparent color.2. With the cooling rate, the crystallization temperature and the crystallization time as the experimental factors, the experiment was conducted to study the Second-step dry fractionation of Ningxiang pig fat, further reduce the melting point of liquefied lard. A single factor experiment was carried to determine the cooling rate of the dry process:0.5-1.5?/h, crystallization temperature range of 12-16 ?, curing crystallization time 20-30h. Through the orthogonal experiment can be concluded that dry fractionation process conditions for the points:cooling rate is 0.5 ?/h, the crystallization temperature is 16?, keep crystallization time is 30h. Through the validation test, the yield of liquid oil can reach 78.63%, the liquid oil melting point of 11.92 degrees Celsius, the test liquid oil has a pig oil fragrance, color transparent.3. The use of cholesterol oxidase to reduce cholesterol in lard. By single factor test to determine the response surface of the range of factors. Cholesterol oxidase content for 2.5% lard, cholesterol oxidase reaction time is 6 h, the reaction temperature ot 45 ? of the Factors of in the middle level of response surface test. Through the response surface optimization test, the optimum technological conditions were obtained as follows:enzyme dosage 2.75%, reaction time 6.05 h, reaction temperature 43.89 ?. Model validation test (enzyme dosage 2.75%, reaction time 6.05 h, reaction temperature 43.89 degrees C), after removal of cholesterol, the lard average cholesterol content was 32.47%, and the average removal rate was 58.09%. By the fatty acid composition, it can be seen that the fatty acid composition of the sample after cholesterol oxidase treatment is basically unchanged.