Amino Acid Composition of Macrobrachium vollenhovenii and Callinectes amnicola from Badagry Creek, Lagos, Nigeria

Abstract

Amino acid composition of the body parts of Macrobrachium vollenhovenii and Callinectes amnicola collected from Badagry creek were assessed and determined. Fifteen and twelve samples of M. vollenhovenii and C. amnicola respectively were used in the study. The weight of the prawns ranged from 4.09g-17.50g while the crab ranged from 31.00g-119.82g. The prawns were separated into three (3) different parts which are the whole prawn, flesh and exoskeleton while the crabs were limited to the whole crab and the flesh. Chemical analysis was carried out following the modified method AOAC method 982.30, while the data obtained were analyzed using SPSS version 20.0. Eighteen amino acids were reported made up of ten (10) essential amino acids (EAA) and eight non-essential amino acids (NEAA). The EAA were arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan and valine, while the NEAA were glycine, alanine, proline, aspartate, glutamate, tyrosine and cystine. The ratio of EAA: NEAA in M. vollenhovenii and C. amnicola was 1.25. There were significant differences (p=0.05) among the amino acids from the various parts analysed. Glutamate recorded the highest concentration while cystine recorded the lowest concentration in both crustaceans. Thus, these crustaceans probably play important roles in learning and sensitivity due to the concentration of glutamate which is a powerful excitatory neurotransmitter that is released by nerve cells in the brain. On the basis of nutrition and higher concentration of amino acids, M. vollenhoveni and C. amnicola are better sources of protein and can serves as substitutes for other proteinous food.Food and tissue proteins contain 20 different amino acids including essential and non-essential amino acids of nutritional importance. Shellfishes contain varying levels of high quality protein rich in all the valuable dietary essential amino acids. Amino acids are mainly obtained from proteins in diet therefore a sufficient quantity of dietary protein is required for growth, survival, development, reproduction and maintaining good health throughout life [3,4].Since amino acids have been reported to have a lot of biological importance, and prawns/crabs are regarded as good sources of proteins, this study was carried out to determine the amino acid composition of the African river prawn, Macrobrachium vollenhovenii and the crab, Callinectes amnicola from Badagry Creek, Lagos, Southwest Nigeria.