Research On Extraction And The Mechanism Of Wheat Germ Oil By Aqueous Enzymatic

Wheat germ oil is rich in vitamin E, unsaturated fatty acids, with a high nutritional value is wheat germ subsequent processing and utilization of high-value-added products. Wheat germ oil content is low, difficult to extract, limiting the development of a wheat germ oil. In a variety of extraction methods, aqueous enzymatic extraction method with development potential, but the current study, immature technology. In this paper, wheat germ as the object of study, ultrasound-assisted extraction process of aqueous enzymatic method, aqueous enzymatic extraction of demulsification, oil extraction mechanism, effects of different methods of extraction of wheat germ oil were researched, the results indicate:1. On the basis of single-factor test, the amount of composite enzymes, enzyme hydrolysis pH, enzyme hydrolysis temperature and reaction time were chosen as influencing factors. Wheat germ oil yield was applied as response value. Box-Behnken central composite experimental design was applied to establish the mathematical model. Design-expert software is used for the response surface analysis. Results show that optimum conditions for ultrasound-assisted aqueous enzymatic extraction of wheat germ oil were:water ratio of 6:1, ultrasonic power 400w, treatment for 20 min, compound enzyme dosage 2.27%, enzymatic hydrolysis pH=5, reaction temperature 45℃, hydrolysis time 6.1h, wheat germ oil yield is 9.692%.2. In the germ oil extraction process, centrifugal, heating, regulating pH (adding electrolyte), extraction operations have demulsification effect, just not the same degree of demulsification. Through the combination of frozen and ultrasonic and microwave, the time is reduced, the demulsification effect is better. The oil is cold pressed oil, pale yellow, clear and transparent, has the unique flavor of wheat germ, nutrients are not destroyed. And the oil recovery rate reached 95-98%.3. Study on aqueous enzymatic extraction of oil mechanism showed that, cell structure collapsed in ultrasonic process, cell stripping internal small lipid complex, at the same time, the cell wall was hydrolyzed in acidic environment, causes the cells to tissue softening, it reveals that the ultrasonic treatment on the extraction of oil from the ultrastructural effect.In the process of aqueous enzymatic extraction of oil, the main role of protease is to destroy the lipid complex, the main role of cellulase is to make the cell wall degradation, destruction, compound enzyme combined with the two part, the oil dissolved out of the cell, easy to be extracted. 4. Based on the different methods of extracting wheat germ oil, the conclusion can be drawn,4 methods of extraction of fatty acid composition of wheat germ oil is basically the same, mainly including palmitic acid, stearic acid, oleic acid, linoleic acid, aqueous enzymatic extraction of wheat germ oil and the highest content of unsaturated fatty acids.This result is consistent with the peroxide value. From the composition of fatty acid, aqueous enzymatic extraction of wheat germ oil of the highest quality. According to the analysis of the results of HPLC, vitamin E content of germ oil extracted by aqueous enzymatic was the highest. Most of the indexes of germ oil using aqueous enzymatic method is better than the oil extracted by the traditional process.