Influence of Temperature and Screw Pressing on the Quality of Cassava Leaf Fractions

In this study, the development of a mild processing method for cassava leaves to remove cyanogenic compounds with minimum nutritional loss is evaluated. Fresh leaves were reduced in size using a mixer at temperatures of 25 (room temperature), 55, 80, and 100 degrees C for 1 min before screw pressing to separate the juice and press cake fractions. Cyanide content in the fresh leaves was reduced by 60% at 100 degrees C and by 57% in the juice sample processed at 25 degrees C. The press cake cyanide content was low (210 ppm) in both the control and the sample that was processed at 55 degrees C. An increase in the temperature for processing cassava leaves to 100 degrees C resulted in a loss of 5-13% of the CP and 7-18% of the vitamin C content. The press-cake fraction had high beta-carotene, lutein, and chlorophyll a and b content, and low values were registered for the juice fraction. Processing fresh cassava leaves at 25 and 55 degrees C resulted in fractions with high beta-carotene and lutein content. The protein quality of press cake was better than that of juice for feed. Short thermal shredding with pressing resulted in minimal loss of nutrients and a significant reduction of cyanide in the leaves.