Enzymatic Preparation And Property Research Of Medium And Short Carbon Chain Fatty Acids Structural Oil Based On Coconut Oil

Coconut oil is a kind of plant oil which is extracted from coconut meat, in China, the use of coconut mainly concentrated in coconut juice, the meat is usually discarded, and this situation results in a tremendous waste. In this paper, coconut oil was taken as the research object, and the extraction was carried out by the method of ultrasonic-subcritical cooperation; the structural oil was prepared by the reaction of coconut oil, short chain fatty acid and enzyme; the physical and chemical indexes, fatty acid composition, storage stability and antioxidant activity in vitro of coconut oil and structural oil were analyzed;the process conditions of structural oil micro capsules were studied, and the powder oil was prepared, and the related indexes of the products are analyzed; the powder oil was applied to the preparation of ice cream, and the technological conditions were optimized.Specific research contents and results are as follows:1. The extraction technology of coconut oil by ultrasonic-subcritical cooperation was studied, the effects of feed liquid ratio, time, temperature and power ratio on the rate of oil were investigated, and the results showed that when the feed liquid ratio was 1:13, the time was 14.5min, the temperature was 90 degrees and the power ratio was 30% ( total power:240w) , the rate of oil was the highest, which was about 49.56%.2. In this paper, the optimum technology and the related indexes of the preparation of medium and short carbon chain fatty acids structural oil based on coconut oil were studied.First, the types of acyl donor and enzyme were determined by comparison. Second, the effects of reaction temperature, time, substrate ratio and enzyme addition on the insertion rate of acyl donors were determined by single factor experiments, then the optimal reaction conditions were investigated by orthogonal experiment. The optimal reaction conditions were: 60 degrees, 8 hours of time, substrate ratio of 4:1, enzyme addition of 8%. The results showed that the effect of time and enzyme dosage on the insertion rate was very significant. Under these conditions, the insertion rate of the acyl donor could reach to 11.43%. The products with the unique aroma of coconut were colorless and transparent.Then fatty acid composition and relative indexes of the products were analyzed and compared with that of the former.3. The storage stability and antioxidation in vitro of medium and short carbon chain fatty acids structural oil based on coconut oil (hereinafter referred to as structural oil)were studied, and it was compared with the original ecological coconut oil(hereinafter referred to as coconut oil). First, the change of acid value and peroxide value of structural oil at room temperature was researched, the result showed that the structural oil had a good storage stability, and several common antioxidants are effective for the structural oil. The content of total phenolic acid in the oil was determined by the folin phenol reagent method,the result expressed as gallic acid content was (0.0767+0.0011) mg/mL. The DPPH free radical scavenging rate, ABTS free radical scavenging rate, OH radical scavenging rate,Fe3+ reduction ability and total antioxidant capacity were determined, the results were(34.43+0.81)%, (16.62+0.61)%, (29.87+0.53)%, (0.0143+0.0006) mg/mL (expressed as the content of Vc) and (99.5667+0.7638)?mol/L (expressed as the content of ferrous sulfate).4. The optimum processing technology and the related indexes of micro capsule manufactured by medium and short carbon chain fatty acids structural oil based on coconut oil with spray drying method were studied. Firstly, the type of wall material was determined by comparing the emulsion stability and the micro capsules efficiency of the products under the same conditions. Secondly, the effect of emulsifier dosage, wall material ratio, core wall ratio, solid content and inlet temperature on the micro capsules efficiency was determined by single factor experiment. The optimal reaction conditions are optimized by response surface optimization. The optimum technological conditions are as follows: the dosage of emulsifier 1%, the wall material ratio 2:1, the core wall ratio 0.3:1,the solid content 15%, the inlet air temperature of 190 degrees, the predictive value of the micro capsules efficiency was 74.76%. According to this condition, the result is 73.79%,the products was milky white powder solid, the particle is small and uniform, and it had the characteristic dairy aroma. The physical and chemical indexes of the products were analyzed, and the oxidation stability, electron microscope, UV and IR analysis were carried out, the results showed that the products had good solubility and storage stability, a small amount of unsaturated double bond of the oil were oxidized, and the functional groups did not change.5. The process conditions of preparation of ice cream from structural oil microcapsule were studied, the effects of the amount of microcapsules, the amount of emulsifier and the amount of stabilizer on the sensory score and expansion rate of ice cream were investigated.The results showed that when the amount of microcapsule was 3%, the amount of emulsifier added was about 0.7%, and the amount of stabilizer was as high as 0.06%, the expansion rate of ice cream was the highest, which was about 83.58%.