Volatile profiles of Allium tenuissimum L. flower fried by four different oils, using SPME–GC–MS, and sensory evaluation coupled with partial least squares regression

Abstract

Allium tenuissimum L. flower is a kind of spice widely used in Northwest China, which is more fragrant after being fried. In order to assess the volatile compounds of fried Allium tenuissimum flower, solid-phase microextraction with gas chromatography–mass spectrometry (SPME–GC–MS) and gas chromatography–olfactometry (GC–O) were used to analyze the flower of Allium tenuissimum L. fried in four kinds of oil (rapeseed oil, peanut oil, soybean oil, and sunflower oil). A total of 50 volatiles were identified, including eight sulfur-containing compounds, ten nitrogen-containing heterocyclics, seven oxygen-containing heterocycles, eleven aldehydes, six acids and eight other compounds. Sensory evaluation revealed highest scores in onion, caramel, grassy, fatty and roasty attributes. Positive correlations between sensory attributes and aroma-active compounds were elaborated by partial least squares regression (PLSR) analysis. PLSR indicated that the sensory attribute of ‘roasted’ was positively associated with methylpyrazine, 2,5-dimethylpyrazine, and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one. The sensory attribute of ‘onion’ was significant positively associated with dimethyl disulfide and dimethyl trisulfide. 2-Pentylfuran, furfural, and 2-furanmethanol had a significant positive impact on ‘caramel’ attribute. (E)-2-Heptenal and (E,E)-2,4-heptadienal were positively related to ‘grassy’ attribute. ‘Fatty’ attribute was significantly positively correlated with (E,E)-2,4-nonadienal, (E,E)-2,4-decadienal, and heptanoic acid.