Amino Acids Composition of Some Wild Edible Mushrooms from Southern Cross River State, Nigeria

Abstract

Aims: To document the amino acid content of six wild edible mushrooms - Lentinus squarrosulus Mont., Auricularia auricular-judae (Bull.) Wettst., Mycetinis copelandii (Desjardin) A.W. Wilson & Desjardin, Baeospora myosura (Fr.) Singer, Pleurotus ostreatus (Jacq. ex. fr) Kummer and Volvariella volvacea (Bull. ex. Fr.) Singer - found in southern Cross River State, Nigeria. Place and duration of study: Department of Plant and Ecological Studies, University of Calabar, Cross River State, Nigeria, between May 2018 and August 2018. Methodology: The amino acids content of these mushrooms were quantitatively estimated. The samples were obtained and analyzed for amino acids on dry weight basis using standard methods. Results: The amino acid analysis quantitatively estimated the alanine, arginine, aspartic acid, cystine, glutamic acid, glycine, histidine, Isoleucine, leucine, lysine, methionine, norleucine, phenylalanine, proline, serine; threonine; tryptophan; tyrosine and valine component of the mushroom samples. All the mushrooms studied contained nine essential, five conditionally essential and four non-essential amino acids with glutamic acid as the most predominant (values ranging from 6.66 to 17.26g/100g protein). Cysteine (0.30-0.48g/100g protein) and methionine (0.64-1-1.7g/100g protein) were the lowest in concentration. The concentrations of five of these essential amino acids phenylalanine (3.55 mg/100g protein), valine (3.62 mg/100g protein), threonine (3.39 mg/100g protein), tryptophan (1.58 mg/100g protein), and lysine (3.23 mg/100g protein) in P. ostreatus were significantly (P≤0.05) higher than found in the other mushrooms. For the nonessential and conditionally essential amino acids, the concentrations of arginine (6.02 mg/100g protein), aspartic acid (6.88 mg/100g protein), cysteine (0.48 mg/100g protein), glutamine (17.26 mg/100g protein) and glycine (2.61 mg/100g protein) in P. ostreatus were significantly higher (P≤0.05) than found in the other mushrooms. Conclusion: This information reveals that mushrooms are potential sources of quality protein with substantial proportion of essential amino acids indicating they can play a significant role in the fight against malnutrition.