| Popis: |
The metabolite and flavor characteristics of roasted germinated sunflower seeds (RGSF) were evaluated and compared with those of roasted ungerminated sunflower seeds (RUSF) by gas chromatograph-flame ionization detector (GC-FID) and headspace solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS). During roasting, α-tocopherol, β-sitosterol, fructose, and glucose content were higher at 125 °C compared to those at 135 and 145 °C in RGSF, and lower reductions of alanine, glycine, phenylalanine, serine, asparagine, and γ-aminobutyric acid (GABA) content at 125 °C in RGSF. Considering their nutritional value, it is suggested that sunflower seeds are roasted at 125 °C. The dominant volatile compounds in RGSF were α-pinene, furfural, pyrazines, 1-octen-3-ol, and 2-methylbutanal. High-temperature heating for long term led to a large accumulation of unpleasant odors like pyridine, hexanal and nonanal, especially in RUSF. To examine the distribution of the individual metabolites and flavor compounds among different roasting conditions. A heatmap diagram combined with agglomerative hierarchical clustering (AHC) analysis and principal component analysis (PCA) showed that most Maillard reaction substitutes (amino acids and reducing sugars), products (2-methylpyrazine 2-ethyl-3,5-dimethyl-pyrazine, and 3-ethyl-2,5-dimethylpyrazine), and Strecker degradation products (3-methylbutanal, 2-methylbutanal, and isobutanal) contributed to separate RGSF from RUSF. |
