Nutritional analysis, volatile composition, antimicrobial and antioxidant properties of Australian green ants (Oecophylla smaragdina)

Abstract

Edible green ants (Oecophylla smaragdina) are distributed in Asia, Australia, and the Pacific Islands, and are known for their pharmacological and nutritional applications, yet various properties are to be explored. Nutritional value, volatile compounds, antimicrobial and antioxidant potential were determined in four body regions [ant nest, whole ant, anterior part of the body, and gaster]. Proximate analysis revealed the anterior part have higher protein and fibre content, whilst fat content was higher in the gaster. GC–MS analysis revealed the complexity of ant nest with most compounds being organic acids, alcohols and alkanes. Antimicrobial activity was observed for whole ants (ZOI: 13.3 ± 0.8 mm) and anterior part (ZOI: 11.9 ± 0.5 mm) methanol extracted against Staphylococcus aureus (~104 CFU/ml). Whole ants methanol (813 ± 22.6 µg TROLOX eq/g of DW) and water (617.6 ± 59.2 µg TROLOX eq/g of DW) extracted exhibited higher free radical scavenging capacity amongst the four ant body regions. Whole ants water extracted (7 ± 0.4 mg GAE/g of DW) had the highest total phenolic content. In the methanol extracts, the gaster (6.2 ± 0.2 mg GAE/g of DW) exhibited the highest phenolic content. Whole ants exhibit good antioxidant and antimicrobial activity and considerable folate content.