Characterizing Red Radish Pigment Off-Odor and Aroma-Active Compounds by Sensory Evaluation, Gas Chromatography-Mass Spectrometry/Olfactometry and Partial Least Square Regression.

Aroma-active compounds of red radish pigment extracts (water extract, phosphoric acidified water extracts (PAW), 10 min water or phosphoric acidified water preheated extracts (HW or HPAW), Chongqing, and Yunan extracts) were identified and characterized via sensory evaluation, gas chromatography-mass spectrometry (GC-MS), and gas chromatography-mass spectrometry with olfactometry (GC-MS/O). Three sensory attributes, namely radish odor (desirable) and radish off-odor and sulfur-like odor (undesirable), were selected to characterize the red radish pigment extracts. The correlation between the aroma-active compounds (GC-MS) and sensory attributes was studied using partial least square regression (PLSR). The sensory evaluation results revealed that Chongqing (9.30 and 8.80), water (9.00 and 9.10), Yunan (7.80 and 8.00), and HW (6.90 and 7.20) extracts showed higher radish off-odor and sulfur-like odor scores, while PAW-2.5 (7.70) and HPAW-2.5 (7.60) extracts showed higher radish odor scores. Sulfur-containing compounds, allyl isothiocyanate, 1-butyl isothiocyanate, acetonitrile, oxygen-containing compounds, terpenes, and naphthalene were positively and significantly correlated with radish off-odor and sulfur-like odor but negatively and significantly correlated to radish odor. 3-(Methylthio)propyl isothiocyanate and pyridine were positively and significantly correlated to radish odor. Additionally, 3-buten-1-yl isothiocyanate and 4-(methylthio)-3-butenyl isothiocyanate showed positive but not significant impact on radish odor. Based on their higher volatile concentration, the aroma-active compounds of the four extracts were evaluated using GC-MS/O. Thirty-three aroma-active compounds with different odor intensities were identified to be the major odorant compounds for red radish pigment extracts by panelists. Conclusively, the red radish pigment extraction conditions play a great role in its sensory characteristics. [ABSTRACT FROM AUTHOR]