THERMAL-STABILITY OF SOME METABOLICALLY CONJUGATED POTENTIAL PRECURSORS OF FLAVOR COMPONENTS IN MEAT AND MILK

The stability of selected metabolic conjugates (phenylphosphate, pheny lglucuronidel naphthylglucuronide, and naphthylsulfate) was evaluated in model systems. Phenylphosphate was less stable than the glucuronide s and the sulfate, especially under neutral (pH 6.8) and acidic condit ions (pH 1.5). Phenylphosphate was completely degraded after 1.7 hr at 100-degrees-C, and after 0.3 hr at 150-degrees-C at pH 6.8. The glucu ronide and sulfate conjugates were especially stable under neutral con ditions (pH 6.8) requiring > 5 hr for complete hydrolysis at 100-degre es-C. All conjugates were quite stable to hydrolysis under alkaline co nditions (pH 11). The presence of certain organic solvents (ethyl acet ate or ethyl ether) caused rapid hydrolysis of conjugates under very m ild conditions (40-degrees-C for 30 min). This information may improve understanding of flavor production from animal products.