Purification of Azadirachta indica seed cake and its impact on nutritional and antinutritional factors.

Azadirachta indica Juss. (family Meliaceae) is a vital plant with multiple agricultural and medicinal utilities. The seed cake after oil extraction can be a good source of nutrition in animal feed. The limitation to its use is the presence of azadirachtin, salannin, and other bitter constituents. To make it palatable for use as a source of animal nutrition it was detoxified using 50 and 80% methanol and was analyzed for contents of azadirachtin, salannin, and nutritional contents such as total carbohydrates, protein, crude fiber, in vitro protein digestibility, and trypsin inhibitor activity (TIA), prior to and after purification. The contents of azadirachtin and salannin were quantified using HPTLC and HPLC. Various validation parameters were also investigated. A highly significant decrease of antinutritional factor (TIA) was recorded after purification of samples, retaining the contents of protein, carbohydrates, crude fiber, and in vitro protein digestibility. The purified seed cake was found to be free of azadirachtin and salannin contents.