Evaluation of the freezing and drying process on the physicochemical properties of the agave white worm (Aegiale hesperiaris).

The agave white worm (Aegiale hesperiaris) is a seasonal larva that is stored frozen (-18 °C) for marketing. However, the effects of freezing the larva on its nutritive and bioactive components have not been studied. Therefore, this study investigated the effects of freezing the white agave larva on its nutritive and bioactive components and evaluated two drying methods subsequently used for its preservation. Larvae collected in 2023 and 2024 were frozen and after thawing at room temperature (~25 °C) and then drying by convection (40 °C) or freeze-drying (-55 °C), their chemical and bioactive constituents were determined. In terms of nutrient composition, GBL24 was the best preservation method. The freezing process had an influence on the chemical composition of the larvae, especially on the soluble compounds that are formed during thawing. For this reason, the insoluble compounds in the larvae collected in 2023 were more than twice as high as in the larvae collected in 2024. Two main fatty acids were detected in the larvae according to their concentration, namely, linolelaidic acid methyl ester (27-42.40%) and methyl palmitate (23.19-33.02%), which decreased after the drying process, while an increase in methyl butyrate and methyl palmitoleate was observed in the freeze-dried samples (0.8-4.67-fold, respectively). Among the entomochemicals present in the larvae that are considered bioactive compounds, alkaloids, triterpenoids, tannins and saponins were identified. Saponins and tannins were the most abundant compounds when methanol was used as an extractant. Freeze-drying preserves the highest concentration of bioactive compounds, while convection drying preserves the highest concentration of fatty acids. In view of the above, the drying process is crucial for the preservation of bioactive compounds and fatty acids.