Measurement of β-Glucan in Mushrooms and Mycelial Products

Abstract

A robust and reliable method has been developed for the measurement of β-glucan in mushroom and mycelial products. Total glucan (plus free glucose and glucose from sucrose) was measured using controlled acid hydrolysis with H2SO4 and the glucose released specifically was measured using glucose oxidase/peroxidase reagent. α-Glucan (starch/glycogen) plus free glucose and glucose from sucrose were specifically measured after hydrolysis of starch/glycogen to glucose with glucoamylase and sucrose to glucose plus fructose with invertase and the glucose specifically measured with GOPOD reagent. β-Glucan was determined by the difference. Several acid and enzyme-based methods for the hydrolysis of the β-glucan were compared, and the best option was the method using H2SO4. For most samples, similar β-glucan values were obtained with both the optimized HCl and H2SO4 PROCEDURES: However, in the case of certain samples, specifically Ganoderma lucidum and Poria cocus, the H2SO4 procedure resulted in significantly higher values. Hydrolysis with 2 N trifluoroacetic acid at 120°C was found to be much less effective than either of the other two acids evaluated. Assays based totally on enzymatic hydrolysis, in general, yielded much lower values than those obtained with the H2SO4 procedure.

Circular reuse of bio-resources: the role ofPleurotusspp. in the development of functional foods

“…32.3 g per 100 g d.w., was also observed in one strain of P. ostreatus. 10 Similarly, considering two strains of P. eryngii, the β-glucan content was found to vary between 23.85 and 37.1 g per 100 g d.w. 10,17 Beside the genetic factors, the growing conditions affect the β-glucan content: substrates with a high content of polyphenolic compounds induce an increased synthesis of β-(1→3) D-glucan synthetase in their fruiting bodies. Factors such as the C/N ratio, pH of the substrate and the incubation temperature are also important and species specific.…”

“…Hence, it has been recommended to calculate the β-glucan content as the difference between the total glucans (by measuring glucose obtained through a controlled acid hydrolysis) and the α-glucans (by measuring glucose released from α-glucans through enzymatic hydrolysis with α-amylase and amyloglucosidase). 10 Using this latter approach, a study on the intraspecific variability among 16 strains of P. ostreatus mushrooms revealed that the total glucan content varied in the range 14-25 g per 100 g d.w., with β-glucans in the range of 10.9-22.9 g per 100 g d.w. 24 A higher β-glucan content, i.e. 32.3 g per 100 g d.w., was also observed in one strain of P. ostreatus.…”

“…However, these produced some contradictory results regarding the identification and quantification of some of its components, which raises attention to the methodology applied. 10,11 There are also a growing number of studies on the use of this mushroom in new functional foods. The aim of this review is to summarize the existing literature information on the composition, nutritional value, health studies performed on humans, perception of sensory attributes and acceptability, and food applications of the most common species of Pleurotus, in order to evaluate the potential ability of this mushroom to address the needs of populations with endemic nutritional deficiencies and/or to act as a dietary supplement in the prevention of some diseases.…”

Isolation and Purification of Glucans from an Italian Cultivar of Ziziphus jujuba Mill. and In Vitro Effect on Skin Repair

“…No. K-YBGL Megazyme International, Bray, County Wicklow, Ireland), based on the method published by McCleary and Codd [20]. Human immortalized HaCat keratinocyte cell line was obtained from CLS Cell Lines Service GmbH (Eppelheim, Germany) after a Material Transfer Agreement, and Dulbecco's modified Eagle's medium (DMEM) and fetal bovine serum (FBS) were obtained from Thermo Fisher Scientific (Waltham, MA, USA).…”

“…Cellular debris were removed by extensive washing with PBS. Then, the cells were treated with DMEM and 10% FBS containing glucan samples at different concentrations (10,20,50, and 100 µg mL −1 ). The cells were then incubated at 37 • C in a humidified 5% CO 2 atmosphere for 24 and 48 h. The scratch area was periodically imaged, at 0, 24, and 48 h acquired at 40× of magnification (Leica DMIL, Buccinasco (MI), Italy) in clear field.…”