Optimization of the Protein Sequential Extraction for Quantitative Determination of Albumins, Globulins, Prolamins and Glutelins in Edible Mushrooms

Abstract

For physiological functions development and a healthy life maintenance, a balanced diet, containing carbohydrates, proteins, and lipids, should be practiced, and consumed. The proteins should be highlighted, since are essential macronutrients for cell growth and repair mechanisms in our body. There is an increase in the protein sources consumption, mainly by athletes, aiming an increase of muscle mass and to avoid muscle hypertrophy. Although animal proteins exhibit high digestibility, animal foods can not be accessible and widely consumed, due to high cost or lifestyle choice (vegetarians and vegans). In these sceneries, scientists and food industry are constantly searching for alternative proteins, such as plant and fungi proteins. In view of these information, extraction procedures are proposed to proteins fractionation. However, these procedures must be done to exhaustion to guarantee the acquisition of quantitative values. Therefore, the aims of this work were evaluated the protein distribution in edible mushrooms and optimized the sequential protein extraction procedure to obtain total concentration of albumin, globulin, prolamin and glutelin in edible mushrooms, evidencing the need to carry out extraction procedures until exhaustion to adequately attribute nutritional value to edible mushrooms (pink oyster, shiitake, portobello and champignon). The optimized extraction conditions (extractant, time, concentration, number of extractions) were as follows (H2O, 30 min, ---, 3); (NaCl, 15 min, 0.25 mol L-1, 1); (ethanol, 15 min, 50% (v v-1), 1); (NaOH, 60 min, 0.25 mol L-1, 8) for albumin, globulin, prolamin and glutelin extraction. The champignon mushrooms presented all protein group concentrations below LOD and LOQ. The portobello presented the lowest total proteins concentration. The pink oyster mushroom is the species with the highest concentration of albumin and glutelin as well as total protein concentration 4.7 times higher than shiitake mushroom, which is one of the most consumed mushroom species, showing that this exotic species can be promising mainly due to nutritional characteristics and protein source.