Enzymes have unparalleled advantages over ordinary catalysts and have been widely used in food, medicine, textile, detergent, and cosmetics industries.
Enzymes have unparalleled advantages over ordinary catalysts and have been widely used in food, medicine, textile, detergent and cosmetics industries. Most of these applications are performed in aqueous solution, but many valuable products are insoluble in water, and there are many useful compounds that cannot be synthesized by ordinary chemical methods. Therefore, people want to find a suitable method to produce these high-value products.
There are two approaches to the development of enzyme engineering: one is to modify the enzyme itself, such as protein engineering; the other is to modify the reaction medium, such as the use of non-aqueous media, supercritical fluids, etc., that is, solvent engineering. In 1984, ZaksA and Klibanov A. M first published research reports on the catalytic behavior and thermal stability of lipases in organic phase media, which caused widespread concern. A new branch of traditional enzymology is rapidly emerging, namely non-aqueous enzymology. Now non-aqueous enzymatic methods have shown broad application prospects in peptide synthesis, polymer synthesis, drug synthesis, and stereoisomer resolution. The catalytic role of enzymes in organic media has greatly broadened the scope of enzyme applications, and is a significant area of research in enzyme engineering.
The enzymes currently used in non-aqueous media include oxidoreductases, transferases, hydrolases, and isomerases.Among them, lipase is one of the most widely used and catalyzed enzymes in the organic phase . Lipase is one of the commonly used enzymes in industry. Studies have shown that it can catalyze the hydrolysis reaction of oils and other esters in aqueous solution, and it can also catalyze the reverse reaction of hydrolysis reaction, namely ester synthesis reaction and transesterification reaction, in organic medium. This property of lipase shows that it has great application potential in organic synthesis. As a biocatalyst, lipase can be obtained by fermentation technology, and has now been commercialized. Such as the lipase products produced by Creative Enzymes are greatly welcomed.
Organic phase lipase catalysis has broad application prospects in food, pharmaceutical, fine chemical, organic synthesis and other fields. Countries around the world attach great importance to the technology of organic phase lipase catalytic synthesis of active substances. The application research of organic phase lipase catalytic synthesis technology in food and related fields mainly has the following aspects.
Unsaturated fats such as EPA, DHA, arachidonic acid are beneficial to people's health, and have great potential for application in food, cosmetics, and medicine. But in fact, the current application is still very limited, because these unsaturated fatty acids are very easy to oxidize, make the oil produce odor, and have toxic side effects. Lipase-catalyzed reactions are more suitable than chemical reactions due to their high selectivity and mild reaction conditions, and they avoid substrate changes. Fatty acid VC ester, itself can be used as a nutritional additive, emulsifier, or an effective antioxidant, which has a good protective effect on itself or other unsaturated fatty acids.
Biodiesel is a type of fatty acid monoester made from natural vegetable oils. It has the advantages of clean, renewable and safe. It is a real green energy and can completely replace mineral oil as fuel. At present, biodiesel is mainly produced by chemical methods, that is, transesterification of animal and vegetable fats and low-carbon alcohols such as methanol or ethanol under acidic or alkaline catalysts and high temperatures (230-250 ° C) to generate corresponding fatty acid methyl ester or ethyl ester, and then washed and dried to obtain biodiesel. Chemical synthesis of biodiesel has the following disadvantages: complicated process, excessive alcohol, high energy consumption, deep color, fat contains unsaturated fatty acids, and it is easy to deteriorate at high temperature. In order to solve the above problems, people began to study the bio-enzymatic synthesis of biodiesel and the preparation of corresponding fatty acid esters. Enzymatic synthesis of biodiesel has the advantages of mild conditions, low alcohol consumption, and no pollutant emissions; by-product glycerol is easier to recover and easy to operate; free fatty acids in the reaction can be completely converted into esters.
Short-chain fatty acids such as ethyl or isoamyl esters have strong fruit flavors, and are widely used as flavors and flavors in food, beverages, cosmetics and pharmaceuticals. Due to the low yield and high price of natural flavor esters produced by natural extracts or fermentation methods, it is difficult to commercialize them. Currently, research is being conducted on the use of lipase-catalyzed synthesis technology to meet the increasing demand for natural flavor substances. This method is more specialized than chemical methods and has higher yields than microbial fermentation methods.
There have been many reports on the research of non-aqueous lipase synthesis technology in food and related fields, but most of them are still in the basic research stage of application. There are not many industrialized attempts of lipase-catalyzed synthesis. With the development of genetic engineering and enzyme engineering, the cost of lipase will continue to decrease. Enzyme activity and stability continue to increase. The superiority of enzymatic clean production will definitely promote breakthrough development in this field. Organic phase lipase-catalyzed biotransformation technology represents the future development of the industry.
The Naming and Characteristics of Restriction Endonucleases
Restriction enzymes, also known as restriction endonucleases, are enzymes that cut double-stranded DNA. Its cutting method is to cut the bond between the carbohydrate molecule and the phosphoric acid, and then create a nick on each of the two DNA strands without damaging the nucleotides and bases.
Introduction to Classification and Application of Cellulase
The optimum pH of cellulase is generally 4.5 to 6.5, which acts on cellulose and products derived from cellulose. Microbial cellulase is of great significance in converting insoluble cellulose into glucose and destroying cell walls in fruit and vegetable juice to improve the yield of juice.
Which Enzyme Preparations Are Often Used in Fruit and Vegetable Processing?
The so-called fruit and vegetable processing means to maximize the nutrient content of the fruit and vegetable through various processing methods, improve the edible value, and make the color, aroma and taste of the processed product more perfect.
