Amino acids after heating with glucose

Destruction of Amino Acids After Heating With Glucose at Different Temperatures for One Hour... 

The aroma precursors have been selected by taking into account the significant role of the Maillard reaction. Indeed, most aroma compounds of this type are formed by the reaction of amino acids with sugars or their degradation products. So we have obtained roast beef, roast mutton and heated vegetable aromas after having treated a mixture of amino acids and glucose at different temperatures and for varied times. 

The presence of furopyrazines demonstrates that Furaneol can react as an ot-dicarbonyl compound. Furopyrazines have also been found at trace levels after heating glucose with amino acids (J. Kunert-Kirchhoff and W. Baltes, Zeitschrift fur Lebensmittel- Untersuchung-Forschung, in press). After heating Furaneol alone to 180° C 17 degradation products have been identified. 

The properties of a-D-galactosidase (mol. wt. 3.0 x 10 ) from Saccharomyces carlsbergensis have been shown to be similar to those of other extracellular enzymes in yeast. The carbohydrate content (57 %) consists of D-mannose (ca. 92%), D-glucose (7%), and 2-amino-2-deoxy-D-glucose (1%) 35% of its amino acid residues can be accounted for by L-threonine, L-serine, and l-aspartic acid. Although the enzyme remains active after treatment with sodium dodecyl sulphate, it is denatured by urea and guanidinium chloride. With urea or 60 °C heat denaturation, the enzyme dissociates into two types of subunits and was therefore considered to be the first reported external enzyme from yeast with an oligomeric structure. 

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