Comprehensive analysis of volatile compounds in cold-pressed safflower seed oil from Xinjiang, China.

Lin Wang,Bo Han,Zhuo Chen,Qiaoling Zhao,Wenyu Liu,Wenxia Wu,Changqing Wei

doi:10.1002/fsn3.1369

Abstract

Three varieties of safflower seed oil (SSO) from Xinjiang Autonomous Region, China, were analyzed by headspace solid‐phase micro‐extraction gas chromatography coupled with mass spectrometry (HS‐SPME‐GC‐MS) to reveal volatile components. Overall, 67 volatile components were determined and four compounds including isoamyl alcohol, caproic acid, n‐pentanal, and heptanal were newly identified in SSO as aroma‐active components. Meanwhile, 16 compounds were selected by relative odor activity value (ROAV) to evaluate contributions of single compounds to the overall odor (ROAV > 1), in which nonanal, (Z)‐6‐nonenal, and (E)‐2,4‐decadienal were the top three contributed substances (ROAV > 70). The sensory panel was described as eight definition terms (grassy, fruity, almond, mushroom, fatty, sweet, paddy, and overall fragrance). Principal component analysis (PCA) revealed a significant separation of three cultivars with the first principal component (PC‐1) and the second principal component (PC‐2) expressing 73.9% and 23.1%, respectively. Both PCA and ROAV allowed identifying the compounds positively correlated to sensory evaluation.

Highlights

The major volatile compounds that positively correlated to PC-1 were 2-octene, n-hexanal, acetic acid, and (Z)-2heptenal, and those that positively correlated to PC-2 were n-hexanol, caproic acid (Figure 3b)
This study provides the first data for comparing volatile compound composition of safflower seed oil (SSO) of Xinjiang Autonomous Region, China
relative odor activity value (ROAV) analysis further indicated that the flavor of SSO was more correlated with 12 aldehydes, two alcohols, one alkene, and one heterocyclic compounds according to cultivated varieties

Summary

| MATERIALS AND METHODS

Safflower seeds from the three most popular cultivars (Tacheng HH-4, Bole HH-1, and Changji HH-2) were harvested in early September 2017 from the Xinjiang Autonomous Region, China. The relative odor activity value (ROAV) is used to evaluate the contribution of individual compounds to the overall aroma (Cui, Liu, & Li, 2010). 1-Octen-3-ol had odor threshold of 1 ppb and, being a key odorant with ROAV > 30, was only contribute to the aroma of SSO-2 and FIGURE 1 Relative content (%) of the volatile compounds from different regions of safflower seed oil TA B L E 2 Main odor-active compounds (ROAV ≥ 1) in different varieties of safflower seed oil ROAVb. aVolatile compounds identified in HS-SPME-GC-MS. The major volatile compounds that positively correlated to PC-1 were 2-octene, n-hexanal, acetic acid, and (Z)-2heptenal, and those that positively correlated to PC-2 were n-hexanol, caproic acid (Figure 3b) Such clustering pattern of SSO was revealed in hierarchical clustering analysis (Figure 4). SSO-2 and SSO-3 were closed, and these two samples were separated from SSO-1

| DISCUSSION

Findings

| CONCLUSIONS