The Feasibility of Industrial Production of Lipases with an Emphasis on Its Applications in Food Enrichment
 
Elham Karimi-Nazari; MSc^1,2, Fatemeh Hashemi-Shahraki; MSc^3* & Elhamsadat Mostafavi; MSc^4
 
1 Nutrition and Food Security Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
² Biological Sciences and Technology Institute, Malek Ashtar University of Technology, Tehran, Iran.
³ Department of Biology, School of Sciences, University of Shahrekord, Shahrekord, Iran.
⁴ Department of Chemistry, School of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran.
 

 

Lipases have a wide range of applications in detergents, organic industries, leather industry, environmental management, cosmetics and perfume industries, medical materials and biomaterials. Currently, lipases are utilized to produce enantiomers of enriched primary and secondary alcohols. Nevertheless, it is less used for chiral carboxylic acids and secondary amines. Small esters and short chain carboxylic acids and half of the lipase-synthesized alcohols play an important role in the food industry, such as flavor and aroma. Enzymatic esterification is used by lipases to block intermittent chemical pathways (Jaeger and Eggert, 2002). Transesterification is a method for modifying oils and fats. This activity is provided by fixation of the enzyme on a solid matrix surface such as celite. Transesterification of catalyzed lipase is related to the properties of the enzyme itself, which provides a precise control over the addition of the desired fatty acid in the position of the specific glycerol (Khare and Nakajima, 2000).
The synthesis of esters using lipases can be performed at room temperature, with proper pressure and pH. The products obtained by these methods are purer compared to the products obtained by alternative chemical methods because the chemical catalysis often leads to the creation of non-specific and unwanted products. It also requires a higher temperature, higher pressure, and alternative catalyst recovery. The use of lipases decreases the downstream processes. Therefore, it reduces the overall cost of the process. However, the main problem with this system is low conversion in comparison to chemical processes. Lipases are produced by several microorganisms, including bacteria, fungi, archaea, eukaryotes and also by animals and plants. From a commercial point of view, useful lipases typically result from microorganisms that produce artificial varieties of extracellular lipase. Microbial lipases are more attractive due to persistence in organic solvents, lack of cofactors and different substrate characteristics. The first commercial recombinant commercial lipase was derived from Thermomyces lanuginosus (formerly known as Humicola lanuginosus) and expressed in Aspergillus oryzae (Sharma et al., 2001).
Microbial sources of lipase production
Lipases are widely used in different industrial fields. These enzymes are produced from fungi, molds, or bacteria, and are often secreted in an extracellular manner. In the meantime, microbial lipases are commercially important in terms of low production costs and higher sustainability. The very high potential of biotechnology for microbial lipases is in relation to chemical selection, selectivity of regions, and spatial selectivity of lipases¸ because some of them can be produced in high amounts from microorganisms (Treichel et al., 2010). In the microbial industry, most functional lipases are derived from fungi and bacteria. Fungi are more preferred because fungal enzymes are usually secreted in an extracellular manner, which facilitates the extraction of enzymes from the fermentation environment. In modern processes, fungal genes are expressed in bacterial systems (Jaeger and Eggert, 2002).
Applied plans for food technology
Most of the enzymes used in the industry are mainly applied to modify, alter and break down biomaterials. Most industrial lipases are used to develop flavor and aroma in dairy products and other foods, including meat, vegetables, fruits, cooked foods, and milk and beer production. Industrial applications of phospholipases have been identified in egg yolk treatments for the production of mayonnaise and other emulsions, lecithin modifications and refining of vegetable oil. The introduction of microbial phospholipases specifically enhances the enzyme production economy of refined vegetable oils. The function of phospholipids in egg yolk treatment is the hydrolysis of lecithin. Isolecithin increases the emulsion capacity and thermal stability. Therefore, egg yolks produced can be useful in sweets or porridges, mayonnaise, baby foods and white dough preparations (Sharma et al., 2001).
Dairy industry
Lipases are widely used in dairy industry for the hydrolysis of lipid milk. Using lipases, the length of the fatty acid chain can also be changed to increase the flavor and aroma of cheese. Common uses include cheese ripening speed and lipolysis of butter, fat and cream. Due to the effects of lipase on milk fat and a number of dairy products, especially soft cheeses with a desirable flavor and aroma, free fatty acid is produced. Common sources of lipase that are used to increase the taste and aroma of cheese are prepared from animal tissues, especially the pancreatic glands (cattle and pigs) and pre-gastric juices derived from young ruminants (kidneys, lambs and calves) (Rodrigues and Fernandez-Lafuente, 2010). In some cases, microbial lipases are successfully replaced for pre-gastric lipases. Good quality cheeses are produced using specific microbial lipases or several preparation mixtures. When cheese is incubated in the presence of enzymes at high temperature, the enzyme-modified cheese (EMC) is produced. In other words, an intermediary enabler is produced by the lipase catalytic reaction, which is used as a compound or the ingredient in other products such as sauce, soups and snacks. The fat content of cheese modified by EMC is about 10 times higher
than that of ordinary cheeses (Kilcawley et al., 2006)
Fat and oil industries
The correction of fats and oils is one of the primary areas in the food processing industry that creates a new economy and green technology. Lipases change the lipid characteristics by changing the location of fatty acid chains in the glyceride and replacing one or more fatty acids. In this manner, relatively inexpensive and less favorable lipids can be converted into valuable fats. The lipolytic transformations of fats and oils, esterification and interesterification are utilized to obtain value added products such as certain fats and glycerides, which are of higher potential for hydrolysis than fatty acid production. Derivation of phospholipids from vegetable oils has been recently developed in environmental processes by using highly selective microbial phospholipases (Sun et al., 2012).
The use of granulation to stabilize lipase may be cost effective to produce quality foods. Lipase stabilization is also widely employed for interesterification of fats and oils suitable for frying foods. Although some of the lipases have been reported to be beneficial for stabilization, the lipase extracted from fungi such as Rhizopus japonicus, which is thermally known as a heat-resistant extracellular lipase producing agent, is very useful in utilization of catalyzed lipases transesterification. Lipase from Rhizopus japonicus is a relatively inexpensive, 50 degree heat resistant, acid pH–resistant enzyme. The enzyme is fixed on a celite base to overcome the mass transfer limitations. Due to its porosity and low cost, a celite is considered to be suitable for solvent application, and is preferred to porous bases such as glass. A favorable transesterification activity may be observed due to the stabilization of lipase on celite in a hexane environment, which is reasonably used for the enrichment of docosahexaenoic acid (DHA) in soybean oil. Due to the selectivity of Rhizopus japonicus lipase, on regions 1 and 3 of the glyceride (the “region is meant to be the location of fatty acid on the glycerol molecule), it has been widely used in the food and pharmaceutical industries (Khare and Nakajima, 2000).
Lipases as biosensors for the food industry
The stabilized lipase is fast, accurate and efficient. The application of lipases as a biosensor in the food industry, especially in fats and oils, soft drinks, non-alcoholic beverages, the pharmaceutical industry, as well as in clinical diagnosis, is of particular importance. The basic concept of using lipases as biosensor is to produce glycerol from triacylglycerol in analytical samples and determine the quantity of glycerol released by chemical or enzymatic reactions. Lipases can be fixed on the pH/oxygen electrode in combination with glucose oxidase, which is a lipid biosensor and may be used to detect blood triglycerides and cholesterol (Hasan et al., 2006).
Flour and bakery industry
The baking industry is increasingly focused on lipolytic enzymes. Recent findings suggest that phospholipases can be used to replace or as supplements to traditional emulsions because enzymes reduce the polar lipids of wheat to produce emulsions in situ. Mostly, in order to make the flavor more desirable in the bakery products, lipases release short chain fatty acids via esterification. It not only improves the flavor, but also lengthens the shelf life of bakery products. An artificial lipase expressed in Aspergillus oryzae is used to aid the processing in the baking and bakery industry. All hydrolytic enzymes, including lipases, are used in reducing the effective primary strength and increasing the specific volume of the breads.
The recombinant yeast with Geotricum Lip 2 expresses a protein that has the same properties. In fermentation, the dough prepared with this type of recombinant yeast produces a higher volume and more uniform bread. The yeast with the gene LipA of bacterial lipase leads to higher productivity than enzyme and is considered as an additive in baking bread(Sánchez et al., 2002).
Other Food Processing Industries
In recent years, lipases have been used to produce a variety of products, from juices to fermented vegetables. Lipases facilitate the removal of fat from meat and fish. Sausage processing with microbial lipase is a new technology.. To inhibit the formation of bubbles in chocolate products, a series of fats are designed by enzymatic esterification reactions. The lipase of Candida. rugosa is widely used in food and aromatic processing of products such as ice cream, single-cellular proteins, carbohydrate esters and amino acid derivatives not obtainable by conventional chemical synthesis methods (Hasan et al., 2006, Houde et al., 2004, Kamini et al., 2000).
The extraordinary potential of lipases in food applications indicates the need to develop technology to save time and cost and increase production. A large number of hydrolytic enzymes have applications such as the improvement of flavor and aroma in dairy products (cheese, butter and margarine), alcoholic beverages, milk, chocolate, etc. Food production and diet control, meat and sausage processing have high potentials in certain sources of the food industry. Lipase applications are rapidly expanding. New applications are still being studied in the food industry. Lipase characteristics are being improved by protein and genetic engineering to enhance its applications. In addition, there is a significant commercial potential of using these enzymes in industrial biotechnology.