The aim of this work was to compare cassava leaf protein concentrates produced by different methods and to propose procedures with large yield, protein content and recovery, small tannin content and light color. Protein concentrates were obtained by acid coagulation (pH = 5), acid thermo-coagulation (pH = 4 at 85 and 50 °C), 30% ethanol coagulation and thermo-coagulation (60 °C). Moisture, protein and tannin contents, and brightness and chromatic tonality were determined in protein concentrates and dried milled leaves. The concentrates with the largest yields, protein contents and the lightest colors (acid thermo-coagulation pH 4 and 50 °C and 30% ethanol coagulation) were modified and, after the concentrate obtained by ethanol coagulation, presented a 14.1% protein recovery, a 73.8 brightness and 99.8° chromatic tonality, not differing from the one produced by acid thermo-coagulation. The tannin content was 0.4% in both concentrates. The modified acid thermo-coagulation in pH 4 and 50 °C and 30% ethanol coagulation procedures are correct for cassava leaf protein concentrate production with large protein recovery and light color.
hue angle; color; digital images; food ingredient; tannins