Abstract:

Thermal reactions of cysteine/furfural mixt. were studied as a model system to gain more insight into the influence of structured fluids such as water-in-oil nonionic microemulsions on the generation of aroma compds. The microemulsion systems were composed of: sucrose ester/water/dodecane+alc.(1/1), where the sucrose esters are sucrose stearate (S1570) and sucrose laurate (L1695), and the alcs. are medium-chain alcs. (C2OH to C6OH). Formation of predominately 2-furfurylthiol (FFT) is obtained in the aq. cysteine/furfural system. The formation of FFT was enhanced under similar reaction conditions in water-in-oil microemulsions and led to the formation of two new sulfur compds. that were identified as 2-(2-furyl)-thiazolidine and tentatively N-(2-mercaptovinyl)-2-(2-furanyl)-thiazolidine. The reaction rates (furfural conversion or consumption) decrease with the decrease in the water content and the increase in alc. chain length (C2 to C6 were used as cosurfactant) and with the increase of pH from 4 to 8 in the system contg. butanol as the alc. The rates of reaction increase also with the increase of temp. in the range of temps. studied from 30 to 60°. The kinetic consts. (k) and energy of activation (Ea) were calcd. Microemulsions of W/O are excellent reaction media for the Maillard reaction providing a high selectivity, high conversion rates and specificity. [on SciFinder(R)]