| Fungal polysaccharides have more pharmacol-effects as natural active substances, such as antioxidant, anti-virus, anti-tumor, immunomodulatory etc. Nowadays it becomes popular in medicines and functional foods research areas. Russula fungi resource is rich in Yunnan Province and often used as fresh or dried food. However, there is few studies on the Yunnan wild Russula alutacea fr. Polysaccharide (RAP). In this article, Russula alutacea are analysed by a number of aspects, including the extraction of polysaccharides, the composition of monosaccharides, its antioxidation activity, antibacterial activity, and the effect on a-amylase inhibition. The research provides the foundation for exploitating the healthy food and medicine research. And it also provided a new method for utilizing of RAP. The main research contents and results as follows:(1) The extraction methods of RAP including hot water extration, alkaline extraction, ultrasonic-assisied extraction, enzymatic-assisied extraction.Using the response surface method and orthogonal experimental method optimized these four methods.Our results show that the optimum hot water extracting process was that ratio of material to water was53:1, the extraction time was5.25hour, extraction temperature was91℃. Under the optimal extraction process, the polysaccharide extraction rate was7.08%. Using alkaline extraction method, the polysaccharide extraction rate was12.98%by40time0.83mol/L NaOH and at the temperature of91℃for50min. The optimum extracting process by ultrasonic-assisied extraction were that ultrasonic time is29min, water-feed ratio at50:1(mL:g), water-bath extraction temperature is90℃, time is3h. On this condition extraction efficiency was4.49%.When the pectase adding3%of the raw material mass, the hydrolysis temperature is55℃, pH was4.5, water-feed ratio was40:1(mL:g), the hydrolysis time was6h, water-bath extracting temperature was90℃, water-bath extracting time was1h, the pectase extraction efficiency was9.48%. When the papain adding4%of the raw material mass, the hydrolysis temperature is45℃, pH was4.5, water-feed ratio was40:1(mL:g), the hydrolysis time was6h, water-bath extracting temperature was90℃, water-bath extracting time was1.5h, the papain extraction efficiency was11.33%. And when the cellulase adding5%of the raw material mass, the hydrolysis temperature is55℃, pH was4, water-feed ratio was40:1(mL:g), the hydrolysis time was5h, water-bath extracting temperature was90℃, water-bath extracting time was1.5h, the cellulase extraction efficiency was12.05%.(2) Component analysis of monosaccharides in RAP is reported by gas chromatography. Gas chromatography analysis indicated that the hydrolyzed polysaccharide contains fucose, arabinose, mannose, glucose and galactose. Their mole ratio is0.71:0.44:2.96:20.69:2.18.(3) Antioxidant effects of the RAP were studied in vitro. The result demonstrated that the RAP has the reducing activity, and it can scaveng·OH, NO2-and DPPH·free radicals. RAP also inhibits lecithin peroxide. With increasing concentrations of RAP, the value of all the test indices increased.(4) With the agar diffusion method, RAP was tested for antimicrobial activity to Bacillus subtilis, Escherichia coli, Staphylococcus. Aureus, Bacillus cereus, Aspergillus niger, Rhizopus and Saccharomyces cerevisiae. The results showed that RAP had a powerful inhibiting effect on Bacillus subtilis, Escherichia coli, Staphylococcus. Aureus, Bacillus cereus, Aspergillus niger and Rhizopus, but nearly non-inhibiting effect on Saccharomyces cerevisiae. The minimum inhibitory concentrations (MIC) of different food-borne pathogens were:Bacillus subtilis10mg/mL, Staphylococcus. Aureus10mg/mL, Escherichia coli8mg/mL, Bacillus cereus8mg/mL, Aspergillus niger6mg/mL, Rhizopus20mg/mL.(5) The inhibition activity of RAP on a-amylase was studied. The results showed that RAP showed inhibiting effect on a-amylase in vitro and the effect were increased with the increasing of RAP concentration. |
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