Enhancing the medicinal properties of agaricus subrufescens by growing practices

• Autor(a) principal: Zied, Diego Cunha [UNESP]
• Data de Publicação: 2012
• Outros Autores: Alegría, Francisco José Gea, Giménez, Arturo Pardo
• Tipo de documento: Capítulo de livro
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/227601
• topic: β-glucans; Agaricus subrufescens; Agronomic performance; Growing practices

The Agaricus subrefescens Peck [A. blazei (Murrill) ss. Heinemann] mushroom has been widely studied in various parts of the world, due to its medical and pharmacological properties. As substances of interest, the cell wall of the fungi contains polysaccharides called β-glucans, which have a structural function. During the 1980s, the A. subrufescens mushroom was imported to Japan due to its alleged health effects and is widely used today in Oriental countries both as an edible mushroom, considered a functional food, and as a natural therapy in the form of a medicinal extract, used mostly for the prevention and treatment of cancer. In accordance with Brazilian tradition, it could be useful against a variety of diseases, such as diabetes, atherosclerosis, hepatitis, hypercholesterolemia and heart disease, among others. The mushroom is commercialized in several countries as a nutraceutical product, which is a novel class of dietary supplements, including partially refined extract or dried biomass from the mushroom made into a capsule or tablet. In general, the compositional analysis of A. subrufescens mushrooms is water (84-87%), protein (30-33%), fat (0.82-1.3%), fiber (5.6-6.8%) and minerals (5.9-7.1%), with β-glucan contents between 4.4 and 6.9 g 100 g-1 of mushroom. Active metabolites can be isolated from basidiomes; pure culture mycelia, culture filtrate, and currently numerous attempts are in progress to obtain active metabolites from the mycelia through submerged fermentation culture due the cheaper preparations. The first separation of active anticancer compounds purified from the sodium hydroxide extract of the fruit body occurred in 1989. Following this achievement, several controversies have arisen, mainly regarding the nutraceutical quality of the extracts obtained and in relation to the tests conducted, emphasizing that the chemical composition and the stage of maturity of the mushrooms, as well as the cultivation practices used in growing them, are crucial to obtaining quality basidiomes with high concentrations of β-glucans. Thus, in this book chapter, the problems arising from the variability of the content of β-glucans of mushrooms due to different practices and growing techniques adopted for the A. subrufescens production are discussed. To achieve this, five strains (ABL 99/28, ABL 99/30, ABL 03/44, ABL 04/49 and ABL 06/59), cultivated in three composts (Massai straw + sugar cane bagasse, oat straw + sugar cane bagasse and Aruana straw + sugar cane bagasse), with four casing layers (soil + charcoal, soil + coconut fiber, soil + peat moss and soil + composted pine bark) in four growing environments (climatized chamber, greenhouse with a transparent plastic film, greenhouse with a milky-white plastic film and greenhouse with a Duplalon® plastic film) were studied, with the aim of analyzing the variability of β-glucan content in the harvested mushroom and the agronomic performance of the growing practices. The ABL 04/49 strain cultivated with Massai straw and sugar cane bagasse showed the highest concentrations of β-glucans, but not a best yield, which was achieved by the ABL 99/30 strain cultivated with oat straw + sugar cane bagasse and obtained good β-glucan content and high yield. For agronomic performance, soil + composted pine bark was highlighted, influenced by the cultivation environment, to achieve high yield. Finally, following the presentation of a series of results, the creation of a growing protocol is suggested, which seeks to adopt cultivation practices that enhance the presence of β-glucans in the mushrooms. © 2012 by Nova Science Publishers, Inc. All rights reserved.