Isolation of detoxified cassava (Manihot esculenta L.) leaf protein by alkaline extraction-isoelectric precipitation: Optimization and its characterization

[Display omitted] •Cassava leaf protein was isolated by alkaline extraction-isoelectric precipitation.•Detoxification of cassava leaves extensively reduced toxicants and antinutrients.•The protein reduction after detoxification of cassava leaves was only 9.7 %.•The purity and essential amino acids in the protein increased after detoxification.•The protein’s structural, and techno-functional qualities improved significantly. The cassava leaves protein isolate extraction and optimization were investigated using response surface methodology, where the maximum protein content (21.83 ± 0.41 g/100 g dm), extraction yield (18.31 ± 0.53%), and protein recovery yield (69 ± 1.31%) were obtained at optimal conditions: 114 min extraction time, 46 °C extraction temperature, 23.5 mL/g solvent/solute ratio and pH 11.0 value. The presence of toxicant (Cyanide) and anti-nutrient (tannin) in cassava leaves reduced the bio-accessibility of its protein isolate, strictly prohibiting its consumption. Therefore, detoxification was applied to diminish cyanide and tannin to 85% and 69% in leaves, respectively, where the protein content was reduced to 9.7%. However, detoxified cassava leaf protein isolate exhibited changes in the compositional, structural, morphological, molecular, and thermal characteristics compared to the controlled one. Moreover, the functional properties in protein isolate improved after detoxification at different pH conditions, which can be used as an active ingredient in various foods.