[Protein quality of three strains of Mexican mushrooms (Pleurotus ostreatus)]. / Calidad proteínica de tres cepas mexicanas de setas (Pleurotus ostreatus).

The protein quality of fruits bodies of three Pleurotus ostreatus Mexican strains (INIREB-8, CDBB-H-896 and CDBB-H-897) was evaluated. The protein concentration (Nx4.38) ranged from 17.26 to 19.97 g/100 g dry weight; chemical scores were between 74 and 93% with available lysine as a first limiting amino acid in either INIREB-8 and CDBB-H-896 strains or leucine in CDBB-H-897 strain. The nutritional evaluation revealed 67.75 to 68.38% in vitro digestibility. Relative protein values were from 100.06-107.85%, which were lower than soybean meal and whole egg but larger than those of rice, maize, beans, fava beans and pasta, no differences were found between these values and those of skim milk powder, casein plus methionine and albumin. In accordance with the last results we concluded that due to their essential amino acids content, mushroom proteins are a good complement of cereals; furthermore, it is highly recommended to include Pleurotus in the daily diet.

[Chemical composition of three Mexican strains of mushrooms (Pleurotus ostratus)]. / Composición química de tres cepas mexicanas de setas (Pleurotus ostreatus).

The chemical composition of three Mexican strains of Pleurotus ostreatus (INIREB-8, CDBB-H-896 and CDBB-H-897), were determined. The mushrooms were cultivated on wheat straw in a greenhouse (22-28 degrees C temperature and 80 +/- 5% of relative humidity). Fruits bodies of P. ostreatus contained (all values are expressed in g/100 g dry wt.), protein (N x 6.25): 24.64 +/- 0.21-28.50 +/- 0.26; lipids: 1.10 +/- 0.16-1.85 +/- 0.22; mineral matter: 7.66 +/- 0.23-8.79 +/- 0.25; dietary fibre: 32.14 +/- 0.14-36.81 +/- 0.40; and available carbohydrates: 26.33 +/- 1.04-30.46 +/- 0.21. They contain vitamins (mg/100 g dry wt): riboflavin: 3.31-3.7, thiamin: 1.92-1.96, niacin: 35.98-36.56 and ascorbic acid: 28-35. The main fatty acid was linoleic (0.70-1.19 g/100 g dry wt), it was also reported a low calcium and phosphorus content. Concluding the Pleurotus ostreatus could be a source of some of the complex B vitamins, dietary fiber, protein and linoleic acid.