The Effect of Raw Sugar Addition on Flavor and Retronasal Olfaction Profiles of Processed Brown Sugar

Processed brown sugar is produced by combining non-centrifugal cane sugar (NCS), raw sugar, and molasses. The present study aimed to examine the effects of NCS and raw sugar blending (10%:90%, 50%:50%, 75%:25%, and 90%:10%) on color traits, non-volatile and volatile compounds, retronasal aroma release, and sensory profiles of processed brown sugar, and hence, its flavor quality. The International Commission for Uniform Methods of Sugar Analysis (ICUMSA) color index and the +L* (brightness) and +b* (yellowness) color spaces were gradually altered upon the addition of raw sugar, with strong Pearson's negative correlations between the ICUMSA value and both color space indices (r = -0.9554 and r = -0.9739, respectively), causing a lighter color of the final product. Raw sugar addition also significantly reduced the concentration of non-volatile compounds, such as glucose and organic acids (p < 0.05). As the raw sugar proportion increased from 10 to 90%, the concentrations of total volatile compounds and Maillard reaction products (MRPs), such as pyrazines, furans, and furanones, also decreased significantly from 62.58 to 22.73 µg/100 g and 34.75 to 6.80 µg/100 g, respectively. Reduced intensities of ion masses of in-mouth and in-nose retronasal odors from volatile MRPs, as well as roasted aroma and richness properties, were observed in processed brown sugars with greater raw sugar content. Taken together, a higher proportion of raw sugar in processed brown sugar manufacturing enhances brightness while reducing acidity and aftertaste; however, increased NCS content results in darker products with greater roasted aroma and richness, affecting flavor quality.