Evaluation of Protein and Amino Acid Composition of Selected Spices Grown in the Middle Belt Region of Nigeria

Abstract

A study was conducted to determine the suitability of six different spices (pepper, garlic, ginger, onion, curry leaf and tomatoes) with a view to appraising their nutritive values. For this purpose, crude protein and amino acid composition were determined using standard analytical techniques. The result gave crude protein content in percentage as; pepper (20.11), garlic (19.94), ginger (11.43), onion (10.36), curry leaf (25.67) and tomatoes (19.83). The Total Amino Acid (TAA) of pepper, garlic, ginger, onion, curry leaf and tomatoes were: 48.40, 66.25, 39.21, 40.21, 78.08 and 40.30 g/100g crude protein, respectively. The order of calculated isoelectric point (pI) was curry leaf > garlic > pepper > onion = tomatoes > ginger while that of Predicted Protein Efficiency Ratio (P-PER) was garlic > curry leaf > ginger > pepper > onion > tomatoes. The contents of Essential Amino Acid (EAA) in all the spice samples are generally lower than FAO/WHO recommended values except curry leaf which had a balance content of all the EAAs and garlic that was adequate only in Leu and Phe + Tyr based on FAO/WHO provisional pattern. So curry leaf is considered to be a valuable protein source for the human diet.