Partitioning of Proteins and Anti-Nutrients in Cassava (Manihot esculenta Crantz) Leaf Processing Fractions after Mechanical Extraction and Ultrafiltration

Foods. 2021 Jul 23;10(8):1714. doi: 10.3390/foods10081714.

Abstract

Cassava plays a major role in improving food security and reducing malnutrition. The purpose of this study was to evaluate the influence of mechanical pressing coupled with ultrafiltration (UF) on the quality of different fractions of cassava leaves. Cassava leaves harvested from the greenhouse at the University of Hohenheim were passed through a mechanical screw press to extract the juice and separate the press cake. The juice was centrifuged and filtered to separate the sediment and clear supernatant. The clear supernatant was filtered using a 10 kDa UF system. The nutritional contents of the different fractions were analyzed at each processing step. The total phenolic content was significantly lower in the press cake that had a higher fiber and ash content. The juice and sediment fractions had higher crude protein and total phenolic content. Processing did not negatively affect the concentrations of essential amino acids except for tryptophan in the juice fraction. Non-protein nitrogen was mainly present in the UF permeate, illustrating the potential of UF for upgrading soluble protein fractions. The results indicated that the different fractions during processing could be a possible source of protein for food, feed (juice, sediment, and retentate), or fiber (press cake) for ruminant feed.

Keywords: cassava leaves; fractionation; juice; mechanical pressing; mild processing; press cake; ultrafiltration.