Varietal Composition and Functional Properties of Cassava (Manihot esculenta, Cranzt) Leaf Meal and Leaf Protein Concentrates

Abstract

Cassava leaf samples harvested from local and genetically improved cassava varieties were processed into cassava leaf meal (CLM) and cassava leaf protein concentrate (CLPC) using the low cost village-level fractionation scheme. Chemical and physicochemical analyses were carried out to determine the proximate and amino acids composition and to also ascertain the functional properties of the CLMs and CLPCs. The protein content of the CLPC was high at 470gkg^-1 DM comparable with other conventional protein sources. Crude fibre content was 20gkg^-1 DM. The crude fat was high at 216gkg^-1 DM and nitrogen free extract low at 159gkg^-1 DM. The amino acid profile of the CLPC showed a favourable balance of both essential and non-essential amino acids especially for lysine, leucine, valine and tryptophan at 6.80, 9.65, 6.30 and 2.31 g/16gN, respectively. The limiting amino acid appeared to be methionine at 2.48g/16gN. The gross energy value was also noteworthy at 52.4MJkg^-1. The water absorption capacity (WAC) of CLM averaged 409.6% while that of CLPC averaged 181.5%. Fat absorption capacity (FAC) was 48.3% in CLM and 33.4% in CLPC. Fat emulsion capacity (FEC) value for CLM was 27.4% and 32.5% for CLPC. Fat emulsion stability (FES) values were 41.2% and 42.9% for CLM and CLPC, respectively. The foaming capacity values were 17.7% and 32.1% in the CLM and CLPC, respectively. Foaming stability and least gelation concentration were 4.3cm³ after 30min and 9.0 for CLM as compared with 10.2cm³ and 12.5% for CLPC. The nutritive potential, low-cost and the simplicity of the production technology make CLPC attractive as a source of protein in local food production system as a practicable and ameliorative intervention strategy for the endemic protein under-nutrition in most developing regions.