Study On Supercritical CO₂ Fluid Extraction And The Rheological Properties And Storage Quality Of Horse Fat

This paper focused on the status of Xinjiang horse fat processing research for further exploration,completed supercritical CO₂ fluid extraction processing based on the process of enzymatic hydrolysis extraction, ethyl purification, molecular distillation enrichment of horse fat unsaturated fatty acids in the process. In this paper, used rheometer, the artificial climate incubator, gas chromatography / mass spectrometry（GC / MS） combined with equipment analysis test and compare the differences of the types and content of fatty acids, rheological properties and storage properties of the fatty acids in Xinjiang produced by the above four kinds of processing methods, to provide some reference for the late productization stage of the horse fat, in order to solve the problem of Xinjiang’s high yield, low utilization rate, single product form and so on, to provide technical support, improve the income of farmers and herdsmen, create a higher social benefits. The results were as follows:（1）The Box-Behnken software was used to design the test, and the oil yield was the response index, optimization of extraction pressure, extraction temperature and extraction time. analysis of variance showed that, the influence of the three factors is the order of extraction pressure, extraction temperature, extraction time and extraction time. The optimal process parameters were extracted by 32 MPa, extraction temperature 39℃ and extraction time of 5 h, the fat oil rate is 72.96% under these condition, the product acidity was 0.86, significantly lower than the standard 2.5 " edible vegetable oils and animal fats and health standards ".（2）Using rotational rheometer analysis the rheological characteristics of horse fat, which were processed by enzymatic hydrolysis, ethyl, molecular distillation, super critical CO₂ extraction, via two methods on fixed temperature and variable speed, fixed speed and variable temperature, although the process was not the same, but the product contained in the content and fatty acid composition had certain similarity. In terms of the enzymatic hydrolysis group and the supercritical CO₂ group, the two treatments did not change the molecular configuration of the horse fat, so the rheological properties were very similar, but from the change of temperature, the fatty acid composition and composition difference between them was still very large. Process of different treatment effects on the rheological properties of horse fat was mainly reflected in the changes on the molecular structure of fatty acid and unsaturated fatty acid enrichment degree, and both of them made the processing thiller grease rheological properties.（3） The fatty acids type in the four treatment of horse fat were 14, 13, 11, 15, and the supercritical extraction group was the most; the kinds of saturated fatty acids were 6, 6, 5, 7, and the supercritical extraction group was the most; the kinds of unsaturated fatty acids were 8, 7, 6, 8, the enzyme hydrolysis group and the supercritical extraction group were the most; among them, four kinds of main fatty acid（linolenic acid, linoleic acid, oleic acid, palmitic acid） accounted for 82.36%, 79.41% and 78.13%, 82.12% respectively, the enzyme hydrolysis group and supercritical extraction group topped; the proportion of unsaturated fatty acids was 60.71%, 64.11%, 50.65% and 63.17%, supercritical extraction group topped; the content of single unsaturated fat was 37.13%, 42.94%, 38.36%, 45.32%, and the highest in the supercritical extraction group; the content of polyunsaturated fatty acids was 23.58%, 21.17%, 12.29%, 17.85%, and the highest in the enzymatic hydrolysis group.（4）After tracking and monitoring of 430 d, horse fat acid value treatment in the four groups were lower than that of "edible vegetable oils and animal fats and health standards" provisions of the 2.5, means the shelf life of at least 430 d, and the ethyl ester group, molecular distillation group and super critical group of horse fat preservation is better, the quality change is small, the forecast storage period will be longer.