Enzyme modification products

AMINOACIDS - L-MONOSODIUMGLUTAMATE (MSG)] (Vol 2) -enzyme modification pNZYME APPLICATIONS - INDUSTRIAL] 0/ol9) -in meat products [MEAT PRODUCTS] (Vol 16)... 

Of particular importance for modifications of starch are the enzyme degradation products such as glucose symps, cyclodextrins, maltodextrins, and high fmctose com symps (HFCS). Production of such hydrolysis products requites use of selected starch-degrading enzymes such as a-amylase,... 

Enzyme modification, performance improvement, 3 671 Enzyme multiplied immunological technique (EMIT), 12 97 Enzyme Nomenclature, 17 402 Enzyme-product (EP) complex, 10 318 Enzyme production, Bacillus and, 12 477 Enzymes. See also Restriction enzymes Enzymes, 5 201... 

The following factors appear to control the emulsification properties of milk proteins in food product applications 1) the physico-chemical state of the proteins as influenced by pH, Ca and other polyvalent ions, denaturation, aggregation, enzyme modification, and conditions used to produce the emulsion 2) composition and processing conditions with respect to lipid-protein ratio, chemical emulsifiers, physical state of the fat phase, ionic activities, pH, and viscosity of the dispersion phase surrounding the fat globules and 3) the sequence and process for incorporating the respective components of the emulsion and for forming the emulsion. 

Pallavicini et al. (16) utilized a-chymotrypsin immobilized on chitin to catalyze plastein formation from leaf protein hydrolyzates. When analyzed by gel exclusion chromatography, the products were comparable to those produced by soluble enzymes. Modification of Specific Functional Properties... 

Probably the most common and widespread control mechanisms in cells are allosteric inhibition and allosteric activation. These mechanisms are incorporated into metabolic pathways in many ways, the most frequent being feedback inhibition. This occurs when an end product of a metabolic sequence accumulates and turns off one or more enzymes needed for its own formation. It is often the first enzyme unique to the specific biosynthetic pathway for the product that is inhibited. When a cell makes two or more isoenzymes, only one of them may be inhibited by a particular product. For example, in Fig. 11-1 product P inhibits just one of the two isoenzymes that catalyzes conversion of A to B the other is controlled by an enzyme modification reaction. In bacteria such as E. coli, three isoenzymes, which are labeled I, II, and III in Fig. 11-3, convert aspartate to (3-aspartyl phosphate, the precursor to the end products threonine, isoleucine, methionine, and lysine. Each product inhibits only one of the isoenzymes as shown in the figure. 

A modification of these coloring systems has recently been developed that leads to more sensitive detection. Chemiluminescent substrates have been designed that are converted by the enzymes to products that generate a light signal that can be captured on photographic film. This increases the level of sensitivity about 1000-fold over standard color detection methods. 

Process flavors include processed (reaction) flavors, fat flavors, hydrolysates, autolysates, and enzyme modified flavors. Production of dairy flavor by enzyme modification of butterfat is an example (Lee et al., 1986 Manley, 1994), while meat flavor produced by enzymatic reactions has a much longer history. 

Production of a Romano Cheese Flavor by Enzymic Modification of Butterfat... 

The technology has been developed for production of flavor systems via controlled enzyme modification of butterfat (EMB). Lipases and esterases from various sources are used (J ). Nelson (6) described the essential steps for producing lipolyzed butterfat products. Arnold t al. ( ) published a comprehensive review on the application of lipolytic enzymes. 

The purpose of this study is to investigate the production of a Romano cheese-like flavor by enzyme modification of butterfat. Candida rugosa was selected for enzyme modification of butterfat since it possesses a high lipase activity. 

They observed specific inactivation of the B1 subunit of the E. coli enzyme, the production of free base and chloride, the irreversible modification of protein sulfhydryl groups, and the formation of a new chromophoric absorbance at 320 nm. The tyrosyl radical was not quenched following inactivation, and in this original report a new phosphorus-containing sugar was observed and tentatively identified as 2-deoxyribose 5-diphosphate. Furthermore, inactivation with [ C1]-, [a- P]-, or [5- H]ClCDP did not lead to radiolabeled protein. 

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