Views: 15 Author: Site Editor Publish Time: 2021-10-22 Origin: Site
1. Molecular distillation technology is widely used in the food industry, mainly for the separation of mixed oils. W (monoglycerides of fatty acids) can be obtained; 90% high-purity products. After evaporating the monoglyceride molecules from the surface of the distillate, they are immediately cooled to achieve separation. Using molecular distillation, unreacted glycerol and monoglycerides can be separated in sequence. Monoglycerides are monoglycerides, which are important food emulsifiers. The consumption of monoglycerides currently accounts for two-thirds of the consumption of food emulsifiers. In commodities, it can play the role of emulsification, shortening, fluffing, preservation, etc., and can be used as a special food additive for biscuits, bread, cakes, and candies. Monoglycerides can be prepared by two processes: the esterification reaction of fatty acids and glycerol and the alcoholysis reaction of fats and glycerol. Its raw materials are various fats, fatty acids and glycerin. Monoglycerides synthesized by esterification reaction or alcoholysis reaction usually contain a certain amount of diglycerides and triglycerides, usually w (monoglycerides) = 40% to 50%, and w( Monoglyceride)>; 90% high-purity product. This method is currently the most commonly used and most effective method in the production of high-purity monoglycerides in industry, and the obtained monoglycerides meet the requirements of food grade. Molecular distillation monoglyceride products win by quality, and gradually replace ordinary monoglycerides with low purity and deep color. The market prospect is optimistic. The development of molecular distillation monoglycerides can bring huge profits to enterprises.
2. Refining of fish oil
Extracting natural products from animals, molecular distillation techniques are also widely adopted, such as refined fish oil [8]. Fish oil is rich in all-cis highly unsaturated fatty acids eicosapentaenoic acid (EPA for short) and docosahexaenoic acid (DHA for short). This component has good physiological activity and not only lowers blood fat, lowers blood pressure, It inhibits platelet aggregation and reduces blood viscosity. It also has anti-inflammatory, anti-cancer, and immune-enhancing effects. It is considered to be a potential natural medicine and functional food. EPA and DHA are mainly extracted from marine fish oil, and the traditional separation methods are urea inclusion precipitation method [9] and freezing method [10]. The use of urea inclusion precipitation method can effectively remove the saturated and low-unsaturated fatty acid components in the product, and increase the content of DHA and EPA in the product. However, it is difficult to separate other high-unsaturated fatty acids from DHA and EPA. Can make w(DHA+EPA)<; 80%. Moreover, the product has heavy color, big fishy smell and high peroxide value. It needs to be further decolorized and deodorized before it can be made into a product. The recovery rate is only 16%; the mean free path of the impurity fatty acid in the material is similar to that of EPA and DHA ethyl ester. Although the molecular distillation method can only make w(EPA+DHA)=72 5%, the recovery rate can reach 70%. The product has good color, pure odor and low peroxide value, and the mixture can be divided into DHA and EPA. The content ratio of the product. Therefore, molecular distillation is an effective method to separate and purify EPA and DHA.
3. Deacidification of grease
In the production process of oil, the crude oil extracted from the oil contains a certain amount of free fatty acids, which affects the color, flavor and shelf life of the oil. The deacidification methods of chemical alkali refining or physical distillation in traditional industrial production have certain limitations. Due to the high acid value of the oil, the amount of alkali added in the chemical alkali refining process is large. During the neutralization process of the alkali with free fatty acids, a large amount of neutral oil is also saponified, which makes the refining yield low; physical refining is stripped with steam and gas Acids and oils need to be processed at high temperatures for a long time, which affects the quality of oils. Some active ingredients will overflow with water vapor, which will reduce the nutritional value of health care.
In the study of deacidification of high-acid value pepper seed oil, Ma Chuanguo et al. used molecular distillation to deacidify pepper seed oil with different acid values to obtain relatively high light (fatty acid) and heavy (oil) fractions. It cannot be achieved by current processes such as chemical alkali refining or physical distillation. After the high acid value oils with acid value of 28mgKOH/g and 41 2mgKOH/g are deacidified by molecular distillation, the acid value of the oil drops to 26mgKOH/g and 38mgKOH/g, respectively, and the oil yield is 86%. And 80 9%, the neutral grease is basically not lost. Therefore, molecular distillation technology has a good effect on deacidification of high acid value oils and has broad application prospects.
4. Refining of high-carbon alcohols
High-carbon fatty alcohols refer to straight-chain saturated alcohols with more than twenty carbons, which have a variety of physiological activities. At present, the most concerned is octacosanol and triacontanol. They have the effects of anti-fatigue, lowering blood lipids, protecting liver, and beautifying. They can be used as additives for nutrition and health care agents. Some countries are also used as lipid-lowering drugs, and their development prospects Optimistic.
The process of refining high-carbon alcohols is very complicated. It requires alcohol phase saponification, multiple and multiple solvent extractions, then multiple column chromatography separations, and finally solvent crystallization to obtain a certain purity product. Japan uses the methods of wax saponification, solvent extraction, and vacuum fractionation to obtain products with w (higher alcohol) = 10% to 30%. However, Liu Yuanfa et al. found in the study on the refining of octacosanol in rice bran wax that after multi-stage molecular distillation, a product with w (higher alcohol) = 80% can be obtained. Zhang Xiangnian et al. used long-chain fatty acid higher alcohol esters rich in octacosanol to obtain octacosanol by reduction. That is, using insect wax as a raw material, adding lithium aluminum hydride (AlLiH4) to ether, reducing at 70-80°C for 25 hours to obtain a high-carbon alcohol mixture, and purifying by molecular distillation, the purity of the high-carbon alcohol reaches w (high-carbon alcohol) = 96%, where w (octacosanol) = 16 7%. Using molecular distillation technology to refine high-carbon alcohol, the process is simple, the operation is safe and reliable, and the product quality is high.
