Impact of the Water Content in Peanut Kernels on the Generation of Benzeneacetaldehyde in Roasted Peanut Oils

The impact of water during processing on the sensory properties and aroma-active aldehyde composition of roasted peanut oils was investigated. Peanut kernels with varying initial water contents undergo a roasting and pressing process to produce roasted peanut oil. Almost all volatile compounds decreased in content with an increasing water content, except for benzeneacetaldehyde (BA), hexanal, (E,E)-2,4-decadienal, and (E)-2-octenal. Additionally, with the increasing water content, the intensity of the sweet, steamed, and raw-peanut flavor attributes of the peanut oil was enhanced. The BA content increased by a factor of 7.26, as the water content increased from 4.20 to 52.55% in peanut kernels. Furthermore, the mechanism of BA formation induced by water in the phenylalanine and glucose system was experimentally confirmed using a H₂O isotope model experiment. The results indicated that H₂O donated one oxygen atom to the aldehyde group of BA. Ultimately, water can significantly alter the release of flavor compounds, thereby influencing the overall flavor and sensory properties of the oil.