Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.21 (beta-glucosidase)
 3,280 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Detection of juice-to-juice adulteration based on chemical composition studies is a common method used by government regulatory agencies and food companies. This study investigated the use of major carbohydrate (fructose, glucose and sucrose), polyol (sorbitol), proline, and phenolic profiles as indicators of pear adulteration of apple juice (PAAJ). For this work, a total of 105 authentic apple juice samples from 13 countries and 27 authentic pear juice samples from 5 countries were analyzed. Because the major carbohydrate ranges for these juices showed significant overlap their use as markers for PAAJ detection would be very limited. It was found that sorbitol and proline means for apple and pear were significantly different; however, their broad natural ranges would afford PAAJ at levels up to 30% without detection. In addition, careful selection of the pear juice used as the adulterant would further limit the usefulness of these markers for PAAJ detection. Arbutin was conclusively identified as a marker for pear juice on the basis of its presence in all 27 authentic pear samples and its absence (<0.5 microg/mL) in all 105 apple juice samples analyzed in this study. The application of the developed HPLC-PDA method for arbutin analysis to detect PAAJ at levels as low as 2% (v/v) was demonstrated. A confirmation method for the presence of arbutin in pure pear juice and apple adulterated with pear juice was introduced on the basis of the hydrolysis of arbutin to hydroquinone employing beta-glucosidase, with reactant and product monitoring by HPLC-PDA.
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PMID:Adulteration of apple with pear juice: emphasis on major carbohydrates, proline, and arbutin. 1678 40

Microcalorimetric technique based on heat-output measurement, direct microorganism counting and enzymatic activity determination, have been explored to evaluate the toxic effects of diphenol species (catechol, resorcinol, and hydroquinone) on soil microbial activity. The thermokinetic parameters including growth rate constant (k), inhibitory ratio, half inhibitory concentration and total thermal effect (Q(total)), were calculated and compared using the data obtained from the power-time curves of the microcalorimeter. It was found that addition of high concentrations of diphenol compounds to the soil samples resulted in low microorganism counts. The trend of the number of cultivable microorganisms with increasing concentration of diphenols was similar to specific growth rate k. It appeared that the higher the water soluble carbon (WSC) content, the higher the Q(total) value. The low dehydrogenase and beta-glucosidase found in the soils treated by catechol and hydroquinone was possibly due to their low WSC concentration and high inhibitory effects, respectively. The results reveal the toxicity of the three diphenols in a descending sequence: hydroquinone, resorcinol and catechol. The combination of the three methods is a more comprehensive toxicological investigation of a complex microbiological system. Microcalorimetry is for studying the metabolic growth of microorganisms, the plate counting method is for quantifying the real microbial growth, and the soil enzyme activity is for assessing the intracellular and extracellular activity of microbial biomass. Our proposed methods can provide toxicological information of diphenols to soil microbes from the metabolic, microbial and biochemical point of views which are consistent with and correlated to each other.
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PMID:Study on the toxic effects of diphenol compounds on soil microbial activity by a combination of methods. 1922 21