Nutritional and toxicity assessment of edible insects Lethocerus indicus and Odontotermes obesus among the Mishing tribe of Dhemaji, Assam

The study highlights the proximate composition and toxicity analysis of two edible insects, Lethocerus indicus and Odontotermes obesus consumed by the Mishing tribe of Assam. Proximate analysis of protein, fat, crude fibre and carbohydrate content in Lethocerus indicus was found as (19.8 ± 0.26%), (15.15 ± 0.70%), (13.61 ± 0.15%) and (9.18 ± 0.26%) whereas for Odontotermes obesus it was recorded as (26.40 ± 0.90%), (18.87 ± 0.70%), (13.43 ± 0.40%), (4.40 ± 2.6%) respectively. Calorific value in O. obesus (293 ± 0.34%) was found higher than L. indicus (252.82 ± 2.55%). Toxicity analysis showed the presence of macroelement (calcium and magnesium) as well as microelement (copper, iron, and zinc). Calcium and magnesium concentration in L. indicus was 3.93 ± 0.13 mg/L and 0.05 ± 0.03 mg/L whereas in O. obesus it was 7.17 ± 0.08 mg/L and 2.12 ± 0.03 mg/L respectively. Mineral composition of copper, iron and zinc in L. indicus was 0.20 ± 0.04 mg/L, 1.37 ± 0.06 mg/L, 0.62 ± 0.06 mg/L and in O. obesus their concentration was 0.21 ± 0.03 mg/L, 2.60 ± 0.09 mg/L, 0.27 ± 0.06 mg/L respectively. Toxic heavy metals lead and cadmium were detected with concentrations much higher in L. indicus (3.93 ± 0.13 mg/L and 0.25 ± 0.04 mg/L) than O. obesus (0.87 ± 0.07 mg/L and 0.23 ± 0.03 mg/L) respectively. Although both insect species demonstrated high nutritional potential, providing essential macronutrients and minerals, the presence of toxic heavy metals at measurable levels raises concerns regarding food safety.