Abstract: In order to study the effect of peanut kernel baking temperature on peanut butter flavor and comprehensive quality. Peanut butter was prepared by baking fresh peanut kernels at 130, 140, 150 and 160 ℃ separately for 30 min. Headspace solid phase micro-extraction-gas chromatography-mass spectrometry (GC-MS) was used to analyze the volatile flavor components of peanut butter samples. Acid value, peroxide value, and the contents of vitamin E and sterol were detected and sensory evaluation was carried out to determine the optimal baking temperature for the production of peanut butter. The GC-MS results showed that the relative contents of aldehydes, pyrazines and furans in peanut butter prepared at a baking temperature of 130 ℃ were 32.06%, 14.35% and 10.57%, respectively, having a sweet aroma and flavor. The relative contents of aldehydes, pyrazines and furans in peanut butter prepared at a baking temperature of 140 ℃ were 21.29%, 32.27% and 13.61%, respectively, with the highest contents of 2-ethylpyrazine, 2,5-dimethylpyrazine and 2-ethyl as characteristic flavor, and the peanut butter had a rich roasted peanut-liked flavor without burning odor. The relative contents of aldehydes, pyrazines and furans in peanut butter prepared at a baking temperature of 150 ℃ were 11.74%, 31.95% and 26.58%, respectively, having an enhanced roasted peanut-liked aroma with a slight burning odor. The relative contents of aldehydes, pyrazines and furans in peanut butter prepared at a baking temperature of 160 ℃ were 3.47%, 31.93% and 29.33%, respectively, giving off a noticeable burning smell without sweet aroma and flavor. The contents of vitamin E and sterol in peanut butter changed little with the increase in baking temperature, which were 22.72–23.73 and 126.47–139.25 mg/100 g, respectively. Brightness (L*) of peanut butter gradually decreased with the increase in baking temperature, redness (a*) gradually increased, and yellowness (b*) increased first and then decreased. Acid value did not change significantly, while peroxide value increased first and then decreased. In order to improve the overall quality of peanut butter, the best baking conditions for peanut kernels should be 140 ℃ 30 min.

Key words: peanut butter, peanut kernel, baking temperature, gas chromatography-mass spectrometry, flavor component, comprehensive quality