The effect of processing on chemical constituents of Agaricus spp. mushrooms

Abstract

Agaricus spp. mushrooms are edible fungi of commercial and medicinal importance. Mushrooms convert nutritionally valueless substances into proteinous food with a very efficient bioconversion. Consumption of mushrooms, has increased substantially due to their delicacy, flavour, nutritional and medicinal value, being considered an excellent source of protein, which can contribute to the formulation of a balanced diet. Three species of Agaricus spp. mushrooms were used in this study: Agaricus campestris (L. ex Fr.), Agaricus bisporus (J.E. Lange) and Agaricus blazei (Murrill). This study aimed to examine the effects of blanching, soaking and manufacturing processes (sun drying, oven drying and canning) on some chemical constituents of mushrooms (soluble dry matter, protein and total sugars). The analyses were performed initially at conservation and they were repeated after 6, 12 and 18 months of preservation. Since all treatments caused reduction of the dry matter content, it can be concluded that the smallest decrease during the storage period was recorded by soaked and sun dried A. blazei (1.6 g 100 g-1 FM). The maximum soluble dry matter loss was recorded at blanched and canned A. bisporus (2.8 g 100 g-1 FM). Blanching treatment of preheated (sun dried and oven dried) samples, after storage period, led the protein content to slightly decrease, between 0.4 g 100 g-1 DM and 0.8 g 100 g-1 DM. The smallest decrease of total sugars during the storage period was registered by canned, untreated A. campestris with 1.2 g 100 g-1 DM and the largest decrease was registered by blanched oven dried A. blazei with 2.9 g 100 g-1 DM.