Mechanical Drying of Azadirachta indica A. Juss. Seeds: a Tool to Keep Quality of this Eco-Friendly Bio-Insecticide

Abstract

Products based on Azadirachta indica A. Juss. (Meliaceae) seeds are worldwide renowned as eco-friendly bio-insecticides. However, the improper processing of the seed may cause significant losses in product effectiveness, as the contents of azadirachtin - its main component - may be affected. This paper aims to assess the degradation level of azadirachtin found in A. indica seeds during the kiln drying process under different temperature and airflow conditions. In order to do so, samples of A. indica fresh seeds were crushed and subjected to 11 drying assays in temperatures ranging from 55°C to 65°C and airflows of 0.015 - 0.023 m3.kg-1.s-1, according to the central composite rotatable design 22, with triplicate on the central point. The contents of azadirachtin in both dried and fresh samples were defined through High-Performance Liquid Chromatography (HPLC). Temperatures and airflows had no significant effects on the contents of azadirachtin.