Effects of solvent extraction system and agroecology on oil yield and quality of edible winged termites (Macrotermes spp.) in Zimbabwe

Abstract

This study investigated the effects of solvent system, extraction conditions, and agroecological variation on oil yield and quality of edible winged termites ( Macrotermes spp.) collected from three agroecologies in Zimbabwe represented by Bikita, Mount Darwin and Mutasa districts. A factorial experimental design within a Randomized Complete Block Design was employed to evaluate the influence of solvent type, temperature, extraction time, location, season, and harvesting period on oil yield and lipid composition. Oil yield ranged from 21% to 54%, with ethanol-based binary solvent systems consistently producing higher recoveries than single solvents, demonstrating the importance of solvent polarity interactions in extracting diverse lipid fractions. Yield was significantly influenced (p < 0.05) by agroecological location and harvesting period, with Mutasa district and the late swarming months (December-January) providing the most favourable conditions. Fatty acid composition was dominated by oleic acid (31-40%), indicating a monounsaturated fatty acids -rich lipid profile, while spatial variation revealed that lipid composition and yield are governed by different environmental drivers. Health indices further showed that the oil maintains a stable cardiometabolic profile across locations, despite compositional variation. This study provides new insights by demonstrating that agroecological variation influences not only oil yield, but also lipid quality, highlighting the importance of integrating environmental and processing factors. From an application perspective, the findings support the use of binary solvent systems and site-specific harvesting strategies to improve extraction efficiency and tailor oil functionality, offering a practical framework for scalable edible insect oil production.