Effect of Drying Temperature and Storage Time on the Fatty Acid Composition and Lipid Indices in Wild Edible King Bolete Mushroom (Boletus edulis)

Drying and storage are widely used to preserve edible mushrooms, yet information on how different drying temperatures and prolonged storage affect the relative fatty acid profile of wild Boletus edulis remains limited. This study aimed to determine the effects of drying temperature (20–60 °C), lyophilization, and storage duration (up to 6 months) on the fatty acid methyl ester (FAME) profile and fatty acid profile-derived indices of B. edulis. FAMEs were analyzed by GC-FID and expressed as relative percentages of total identified FAMEs. Linoleic acid predominated (58.7–70.1%), followed by oleic and palmitic acids. Samples dried at 40–60 °C showed higher relative PUFA proportions, approaching those of lyophilized samples. During storage, SFA increased from 12.9% to 16.2%, whereas PUFA decreased from 65.9% to 59.7%. Exploratory multivariate analysis suggested visual grouping of samples according to drying temperature, mainly related to differences in MUFA, SFA, and PUFA proportions. The highest PUFA/SFA ratio was 5.54. Overall, drying conditions and storage duration were associated with shifts in the relative fatty acid profile of B. edulis. Because total lipid content and direct oxidation markers were not measured, these results describe compositional differences and do not demonstrate absolute lipid retention, degradation, or oxidation.