Impact of kernel size and texture on the in vivo and in vitro aroma compounds of roasted peanut and peanut paste

In this study, peanuts were obtained using slotted screens in two sizes: 7 mm (small length) and 11 mm (large length) and in two textures: roasted peanut and peanut paste. The in vitro aroma compounds were determined by solvent-assisted flavor evaporation while the in vivo aroma compounds released in the mouth during consumption were measured by the mouthspace aroma trapping device. Both sets of compounds were analyzed by gas chromatography–mass spectrometry. In the in vivo analysis, 10 aroma compounds, mostly pyrazines, were identified. The in vivo aroma release was affected by size and texture. Small-sized peanuts had higher aroma release than large-sized peanuts, and roasted peanuts had higher aroma release than peanut paste. 2,5-Dimethylpyrazine, 2,3-dimethylpyrazine, trimethylpyrazine, and furfural were identified as the key odorants for the first time in in vivo roasted peanuts using gas chromatography–mass spectrometry–olfactometry (GC–MS–-O). The descriptive analysis results were in parallel with the in vivo released aroma data revealing that the small-sized peanuts produced more roasted peanut aroma than the larger ones.