Glycoside enzymes

In a separate part of this study, the aroma properties of glycoside enzyme hydrolysates added to a white base wine were assessed by duo-trio difference tests with 20 judges. The Australian samples only were evaluated. In tests comparing the... 

All standards were stored under nitrogen at -25°C. The glycosidic enzyme used was Pectinol C obtained from Rohm and Haas. (2-13C) MVA lactone (99 atom %) was obtained from MSD Isotopes. All other reagents were at least analar purity and used as supplied. 

Glycoside enzymes used for GOS production occur in a variety of sources, including plants, animals, and microorganisms such as archaea (working at 70—95°C and pH 5.5-6.5),bacteria (working at 37-80°C and pH 5-7.5), and eukaryota (working at 30-60°C and pH 4.5-7.0). Table 19.3 compiles the yields of GOS obtained by several microorganisms under different reaction conditions. 

The glycoside-enzyme complex in the second and third stages of the mechanism may react with an alcohol instead of water (10), The free sugar is not formed, but rather the glucosyl radical is transferred and a new glycoside is formed according to the equation ... 

D-glucose, dextrose, C Hi20 . The most common hexose sugar. It is present in many plants, and is the sugar of the blood. It is a constituent of starch, cellulose, glycogen, sucrose and many glycosides, from all of which it can be obtained by hydrolysis with acids or enzymes. 

Emulsin, an enzyme readily obtained from almonds, has the property of hydrolysing 3-glycosides. 

One of the most important differences between cellulose and starch is that animals can digest starch Because the glycosidic linkages m starch are a an animal s a glycosidase enzymes can catalyze then hydrolysis to glucose When more glucose is... 

Cyanogemc glycosides are potentially toxic because they liberate hydrogen cyanide on enzyme catalyzed or acidic hydrolysis Give a mechanistic explanation for this behavior for the specific cases of... 

Laser desorption methods are particularly useful for substances of high mass such as natural and synthetic polymers. Glycosides, proteins, large peptides, enzymes, paints, ceramics, bone, and large... 

Identification, isolation, and removal of (polyhydroxy)benzenes from the environment have received increased attention throughout the 1980s and 1990s. The biochemical activity of the benzenepolyols is at least in part based on thek oxidation—reduction potential. Many biochemical studies of these compounds have been made, eg, of enzymic glycoside formation, enzymic hydroxylation and oxidation, biological interactions with biochemically important compounds such as the catecholamines, and humic acid formation. The range of biochemical function of these compounds and thek derivatives is not yet fully understood. 

A slurry of the starch is cooked in the presence of a heat-stable bacterial endo-a-amylase. The enzyme hydrolyzes the a-l,4-glycosidic bonds in pregelatinized starch, the viscosity of the gel rapidly decreases, and maltodextrins are produced. The process may be terrninated at this point. The solution is purified and dried, and the maltodextrins are utilized as blandtasting functional ingredients in dry soup mixes, infant foods, sauces and gravy mixes, etc. 

The term represents the kinetic efficiency of the enzyme. Table 14.4 lists turnover numbers for some representative enzymes. Catalase has the highest turnover number known each molecule of this enzyme can degrade 40 million molecules of HgOg in one second At the other end of the scale, lysozyme requires 2 seconds to cleave a glycosidic bond in its glycan substrate. 

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