The novel discovery of p-hydroxyphenylbutan-2-one (berry note) in Riceberry aroma was characterized by gas chromatography-olfactometry and gas chromatography-time-of-flight mass spectrometry. Odor activity values and aroma extract dilution analysis revealed the high potency of this ketone, vanillin, and guaiacol found within the purple rice. Furthermore, ultrapasteurization (UP), high-temperature short-time (HTST) pasteurization, and ultrahigh-temperature (UHT) sterilization effects on rice beverage aroma were analyzed using Riceberry as a sample. Riceberry's key odorants also remained the primary aromatic contributors in beverage models. Although descriptive sensory analysis showed a slightly lower musty note intensity in HTST beverages compared to the UP sample, their flavor dilution chromatograms were similar. Cluster analysis and R-index ranking test further confirmed aroma similarities during storage. Stored samples sterilized via UHT experienced certain potential off-odors, including acetic acid, propanoic acid, and indole, as opposed to the other beverages. UP was therefore superior to HTST and UHT by extending beverage shelf life without any undesirable odors. PRACTICAL APPLICATION: Ultrapasteurization (UP) retains Riceberry aroma characteristic in beverages and requires minimal modifications beyond conventional pasteurization. UP beverages also surpass those of high-temperature short-time and ultrahigh-temperature by extending shelf life with no noticeable off-odors. In addition, the discovery of p-hydroxyphenylbutan-2-one and the other aroma-active compounds of Riceberry aroma should prove valuable for flavor creation, rice breeding, and rice quality standards.
Keywords: p-hydroxyphenylbutan-2-one (raspberry ketone); Riceberry; aroma; flavor; ultrapasteurization.
© 2020 Institute of Food Technologists®.