Effects of roasting temperature and duration on color and flavor of a sesame oligosaccharide-protein complex in a Maillard reaction model

In this work, sesame oligosaccharides (SOL) and sesame protein isolate (SPI) were isolated from dehulled sesame meal, combined and then tested as a sesame model system, to investigate the effects of roasting temperature and duration on color and flavor. The results demonstrated that SOL was more easily degraded than SPI; specifically, SOL and SPI gradually degraded at 100 °C and 150 °C, respectively. FT-IR analysis showed that characteristic bonds existing in the roasted samples were somewhat destroyed. Galactose, fructose, lysine, cysteine, and arginine showed great reduction and played an important role in color variation and flavor compound formation according to monosaccharide and amino acid analysis. Total color difference (ΔE) and browning intensity increased with roasting temperature and roasting duration. The types and concentrations of volatile flavor compounds were significantly increased, particularly heterocyclics (14.1 %–34.4 %) and phenols (28.4 %–32.4 %), corresponding to 0.3 % and 8.9 % of the unroasted samples.