Analysis of key bitter compounds and construction of predictive bitterness model in green huajiao peels

Huajiao, an important seasoning in China, is beloved by consumers for unique flavor. However, green huajiao exists obvious bitterness during consumption. To clarify the differences in bitter quality of different regions, using high performance liquid chromatography (HPLC) to determine the key bitter compounds contents of green huajiao peels from 20 regions. And hierarchical cluster analysis (HCA) and partial least squares discriminantion analysis (PLS-DA) were employed to better visualize the differences. The results revealed that procyanidin B2 (0.383–1.329mg/g) and quercetin (0.346–0.989mg/g) were the main bitter compounds. Kaempferol, isorhamnetin, isoquercitrin, and umbelliferone were screened as important bitter compounds for distinguishing between regional clusters of green huajiao peels. Furthermore, a predictive model for the bitter intensity of green huajiao peels was effectively constructed from sensory evaluation and key bitter compounds contents by stepwise regression analysis: Y = 4.153 + 4.923 × kaempferol content + 1.032 × isoquercitrin content. These findings provide a comprehensive reference for assessing the bitter quality of green huajiao peels. [Display omitted] •Quantitated key bitter compounds contents in green huajiao peels.•Screened the important chemical markers of green huajiao peels from different regions.•Verified the bitter contribution of key bitter compounds to green huajiao peels.•Established a predictive model for bitter intensity of green huajiao peels.