Protein digestibility using corrected amino acid score method (PDCAAS) of four types of mushrooms grown in Jordan

This study was conducted to evaluate the protein quality of four types of edible mushrooms common in Jordan in terms of protein digestibility - corrected amino acid score (PDCAAS), which is a combination of the chemical score of the limiting amino acid multiplied by true digestibility of the protein. True protein digestibility values were low (61.4, 73.4, 52.6 and 80.5 for Terfezia claveryi, Pleurotus ostreatus, Tricholoma terrum and Agaricus macrosporus, respectively). Based on the essential amino acids pattern requirements for children, the limiting amino acids in P. ostreatus and A. macrosporus protein were sulphur-containing amino acids with chemical scores of 0.61 and 0.50, respectively. However, lysine was the limiting amino acid in the protein of T. claveryi and T. terreum with chemical scores of 0.71 and 0.67, respectively, and the PDCAAS was 0.43, 0.45, 0.35 and 0.40 for the mushrooms types, respectively. Considering the pattern of essential amino acid requirements of laboratory rats, the sulphur containing amino acids were the limiting amino acids in the protein of T. claveryi, P. ostreatus, T. terreum and A. macrosporus with chemical scores of 0.56, 0.30, 0.34 and 0.25, respectively. The PDCAAS were 0.34, 0.22, 0.17 and 0.20, respectively. It is concluded that the four mushroom types studied are of low protein quality.