Enzymes syrup production

Dual Enzyme Processes. In some cases, especially in syrup production in Europe, a liquefaction process is used that incorporates both a thermostable enzyme and a high temperature heat treatment. This type of process provides better hydrolyzate filterability than that attained in an acid liquefaction process (9). Consequendy, dual-enzyme processes were developed that utilized multiple additions of either B. licheniformis or B. stearothermophilus a-amylase and a heat treatment step (see Fig. 1). 

Glucose/com syrups may be manufactured by either an acid or an acid-enzyme process. Acid-catalyzed hydrolysis was the traditional method of corn syrup production and is still the most common method for producing sweeteners up to about 42 DE. Since acid-catalyzed hydrolysis of sweeteners to 55 DE or above creates products of reversion, such as gentiobiose, isomaltose and trehalose, which give unacceptable flavors to the syrup, these syrups are usually made by acid-enzyme processes.18... 

Bajpai, P.K. and Bajpai, P., Cultivation and utilization of Jerusalem artichoke for ethanol, single cell protein, and high-fructose syrup production, Enzyme Microb. Technol., 13, 359-362, 1991. 

Glucose Isomerase. The biggest success story in the enzyme industry has to be glucose isomerase. The very first report of an enzyme that converts glucose to fructose was in 1957 (10). In less than 20 years the enzyme was studied, tailored into a cost effective immobilized form and put into production to make a commodity corn syrup product. In less than 30 years from its first description, it became the largest commercially used immobilized enzyme and responsible for making one of the world s major sweeteners. Since... 

Carasik, W., and J.O. Carroll. 1983. Development of immobilized enzymes for production of high-fructose com syrup. Food Technol. 37, no. 10 85-91. 

Enzym. hydrol. product of bamboo shoot (Phyllostachys edulis) cell wall and of barley straw cell walls. Syrup. 

French researchers provided an alternative to the tartrazine synthetic colorant (E 102), valorizing a phloridzine oxidation product (POP) generated as a by-product of the cider industry. Phloridzine is a polyphenol specific to apples and shows good antioxidant capacity. When apples are pressed to yield juice, phloridzine, oxygen, and polyphenoloxidase enzyme combine to form POP. This brilliant yellow natural colorant with nuances dependent on pH level can be incorporated easily into water-based foods such as beverages (juices, syrups) and confectionery creams because it is stable during production processes. Details about the specific formulations of these colorants are presented in Section 5.1. 

Some of the industrial biocatalysts are nitrile hydralase (Nitto Chemicals), which has a productivity of 50 g acrylamide per litre per hour penicillin G amidase (Smith Kline Beechem and others), which has a productivity of 1 - 2 tonnes 6-APA per kg of the immobilized enzyme glucose isomerase (Novo Nordisk, etc.), which has a productivity of 20 tonnes of high fmctose syrup per kg of immobilized enzyme (Cheetham, 1998). Wandrey et al. (2000) have given an account of industrial biocatalysis past, present, and future. It appears that more than 100 different biotransformations are carried out in industry. In the case of isolated enzymes the cost of enzyme is expected to drop due to an efficient production with genetically engineered microorganisms or higher cells. Rozzell (1999) has discussed myths and realities... 

An overdose of malt flour will introduce too much enzyme activity in the dough, potentially reducing the product to a sticky syrup. Fungal a-amylase is now much more commonly used than malt flour. However, some malt flour is still used, particularly in wholemeal bread. 

Some individuals are unable to metabolise lactose and are lactose intolerant. This is because they lack the enzyme lactase that is needed to metabolise lactose. Lactose intolerance is common in those parts of the world where humans do not consume any dairy products after weaning. In practice this means in Asia, which means that most of the world s population might be lactose intolerant. It is possible to produce lactose removed skim milk. Another approach with lactose is to hydrolyse it to its constituent monosaccharides. As well as avoiding lactose intolerance this allows a syrup to be produced from cheese whey. These syrups are offered as an ingredient for toffees and caramels. 

A critical consideration in the development of biocatalytic systems is the form in which the enzyme or enzyme system is going to be used. There are two general approaches. One is to use isolated enzymes. If these are inexpensive, they can be used as disposable biocatalysts, as is the case for glucose isomerase, ° which is the key biocatalyst in the production of high-fructose corn syrups from starch, or the lipases and proteases that are present in detergents. Alternatively, if enzymes are expensive to produce, they can be immobilized and used repeatedly by recovering the enzyme particles after each use. 

Production of high-fmctose com syrup is an important enzyme process. Because fructose tastes much sweeter than glucose, sucrose is converted into fructose by enzymes, and most soft drinks contain HFCS prepared by enzyme catalysts. Many smaU-volume enzyme processes are practiced (peniciUin is a very important one), and much research and development is underway to find biological processes to make fine chemicals and pharmaceuticals. 

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