Sterol enriched fractions obtained from Agaricus bisporus fruiting bodies and by-products by compressed fluid technologies (PLE and SFE)

Abstract

Ergosterol, ergosta7,22 dienol, ergosta 5,7 dienol, fungisterol,7,6,8(14),22-tetraen-3-ona were the fungal sterols detected in Agaricus bisporus mushrooms after optimization of an sterol extraction method. Their concentration ranged from 3.1-11.2 mg/g dw depending on the strain, casing soil, flush number, developmental stage and sporophore tissue analyzed. Two methods were optimized to obtain sterols enriched extracts from A. bisporus fruiting bodies using pressurized fluid (PLE) and supercritical fluid extractions (SFE). PLE using ethanol as solvent at 10.7 MPa (50ºC and 100ºC) after 5 cycles of 5 min extraction (mixing in the extraction cell the sample with sand in a ratio 1:4) yielded extracts with respect. 5 and 2.9% sterols. Using SFE-CO2 at 40ºC and 9 to 30 MPa fractions containing 60% of sterols were obtained. Both technologies could be also utilized to extract sterols from mushroom by-products (the lower part of the stipe) as a method for their valorization. IntroductionCardiovascular diseases (CVD) are one of the leading causes of death in industrialized countries. Although, up to 80% of the cases could be prevented by changing style life, advertises of public agencies do not have the impact they should.Nowadays, only the consumption of functional foods with hypocholesterolemic properties seems to be better accepted by the CVD risk population than other changes.The functional foods, available at the markets, bearing the claim `able to reduce cholesterol levels in serum´ contain mainly plant phytosterol (Ling & Jones, 1995;Turnham, 1999), or cereal β-glucans. The mechanism of action of the hypocholesterolemic β-glucans is not completely elucidated (Cheickna & Hui, 2012) while apparently the phytosterols are able to impair cholesterol absorption by displacing Edible mushrooms also contain sterols with structural similarities to phytosterols and cholesterol. Thus, these fungal molecules might also act as phytosterols displacing cholesterol from the DMMs. Ergosterol (ergosta-5,7,22-trien-3β-ol) is the major sterol of their hyphae membranes (approx. 80% of the sterols w/w) followed by other 4 derivatives such as ergosta-5,8,22-trien-3-ol, ergosta-7,22-dien-3-ol, ergosta-5,7-dien-3-ol and ergosta-7-en-3-ol In this work, ergosterol and derivatives were measured in several Agaricus bisporus varieties during different cultivation parameters, developmental stages, sporophore tissues etc. The sterols were extracted by both SFE and PLE technologies in order to compare them and define the optimal method and extraction parameters to obtain sterols-enriched fractions. Extractions were carried out using the complete fruiting body or the lower part of the stipe usually discarded as a by-product during harvesting to investigate the possible revalorization of this by-product as starting material to generate ergosterol-enriched fractions for novel functional ingredients with hypocholesterolemic properties. stage was studied). In some cases, the different sporophore tissues, including the lower part of the stipe...

Optimization of microwave-assisted extraction of ergosterol from Agaricus bisporus L. by-products using response surface methodology

“…Depending on the size of the mushroom industry, the amount of by-products ranges between 20 to 35% in weight of fresh mushrooms (Gil-Ramírez et al, 2013;Vasylenko et al, 2008). These byproducts with a high nutritional value are being wasted, but also demand industries to deal with their environmental impact and associated managing costs (Leiva et al, 2015).…”

“…Since mushrooms production/consumption rates are expected to increase in the next years, the environmental problem is expected to growth proportionally and new alternative and profitable solutions need to be explored (Royse, 2014). Several approaches have been postulated, including the production of biofuel, chitin and chitosan, β-glucan and sterols (Chou et al, 2013;Gil-Ramírez et al, 2013;Vasylenko et al, 2008;Wu and Zivanovic, 2004). However, innovative research is crucial to proper evaluate the most feasible and economically viable solutions for theses raising by-product materials from fungal sources.…”

“…They are often time-consuming and require large quantities of solvents, including hazardous ones (Wang et al, 2013). Emerging technologies, such as supercritical fluid extraction, microwave-assisted extraction (MAE), pressurized solvent extraction (PSE) and ultrasound-assisted extraction (UAE) are fast and efficient extraction technologies that have been used in the last decades by the food processing industries and researchers with the purpose of extracting more efficiently major and minor compounds present in natural matrices, saving energy and reagents, avoiding losses and optimizing the extracting yields (Gil-Ramírez et al, 2013;Heleno et al, 2016;Villares et al, 2014). …”

Effect of ergosterol-enriched extracts obtained from Agaricus bisporus on cholesterol absorption using an in vitro digestion model

“…The white button mushroom (Agaricus bisporus) and other edible mushrooms could be novel sources of molecules such as sterols to design hypocholesterolemic functional foods (Gil-Ramírez et al, 2013a, 2013bGuillamón et al, 2010;Roupas, Keogh, Noakes, Margetts, & Taylor, 2012;Schneider et al, 2011). They contain ergosterol (ergosta-5,7,22-trien-3β-ol), the major sterol of their hyphae membranes (approx.…”

“…80% of the sterols w/w), and other derivatives with chemical structures similar to cholesterol and phytosterols. Their concentration ranged from 3.1 to 11.2 mg/g dw depending on spawn varieties, developmental stage and cultivation parameters (Gil-Ramírez et al, 2013a). But, their sporophores or by-products can be submitted to traditional or more advance extraction technologies such as accelerated solvent extraction (ASE) or supercritical fluid extraction (SFE), yielding fungal extracts containing from 3 to 60% fungal sterols (Gil-Ramírez et al, 2013a;Hsu, Lin, & Chen, 2001).…”