Effects of Overripe Banana Processing Techniques on the Chemical Composition and Attractancy to Aedes aegypti and Aedes albopictus
The rising incidence of vector-borne diseases transmitted by mosquitoes has become a significant public health concern. The increasing resistance of mosquitoes to conventional insecticides has prompted the need for alternative control strategies such as Attractive Targeted Sugar Baits (ATSBs). While fruit-based attractants have shown promise, the impact of different production methods on their attractiveness remains underexplored. This study investigates the effect of three production techniques of overripe banana (Musa acuminata) extracts: liquid extraction, syrup concentration, and freeze-drying, on the chemical composition and their attractiveness to Aedes aegypti and Aedes albopictus. Extracts were infused into hydrogel beads and tested in dual-choice olfactometer assays to mosquito vectors Ae. aegypti and Ae. albopictus. Chemical profiling was conducted through Gas chromatography-mass spectrometry (GC-MS) and enzymatic sugar analysis. Results showed that all banana extracts were significantly more attractive than the 10% sucrose control. Among the extracts, syrup concentrates showed the highest attraction (PI = 0.58 {+/-} 0.17 for Ae. aegypti; 0.58 {+/-} 0.14 for Ae. albopictus), followed by freeze-dried (PI = 0.52 {+/-} 0.20; 0.54 {+/-} 0.08) and liquid extracts (PI = -0.40 {+/-} 0.04; 0.49 {+/-} 0.18). GC-MS analysis revealed that freeze-dried powder retained the greatest diversity and abundance of volatile organic compounds (VOCs), especially esters like butyl ethanoate and isoamyl acetate, which are known to influence mosquito behaviour. Although syrup concentration resulted in VOCs degradation, it also generated Maillard reaction products, such as sulphur-containing volatiles, which may enhance olfactory cues. Sugar analysis indicated that both syrup and freeze-dried extracts contained higher levels of sucrose (0.35-0.57 g/100g), glucose (21.20-28.70 g/100g), fructose (14.64-17.89 g/100g), and maltose (9.28-15.56 g/100g), aligning with mosquito preferences. Overall, the findings demonstrate that production techniques significantly influence the chemical composition and attractant potential of overripe banana extracts, offering valuable insights for the development of fruit-based mosquito lures in vector surveillance and control strategies.