Abstract:

The thermal reaction between cysteine and furfural was investigated at 65° C in 5-component food grade oil/water (O/W) microemulsions of R-(+)-limonene/ethanol, EtOH/water/propylene glycol, PG/Tween 60 as apart of a systematic study on the generation of aroma compds. by utilizing structured W/O and O/W fluids. The furfural-cysteine reaction led to the formation of unique aroma compds. such as 2-furfurylthiol, 2-(2-furanyl)thiazolidine (main reaction product), 2-(2-furanyl)thiazoline, and N-(2-mercaptovinyl)-2-(2-furanyl)thiazolidine. These products were detd. and characterized by GC-MS. Enhancement in flavor formation is termed "microemulsion catalysis". The chem. reaction occurs preferably at the interfacial film, and therefore a pseudophase model was assumed to explain the enhanced flavor formation. The product internal compn. is dictated by process conditions such as temp., time, pH, and mainly the nature of the interface. Increasing water/PG ratio leads to a dramatic increase in the initial reaction rate (V0). V0 increased linearly as a function of the aq. phase content, which could be due to the increase in the interfacial concn. of furfural. Microemulsions offer a new reaction medium to produce selective aroma compds. and to optimize their formation. [on SciFinder(R)]