Oligosaccharide preparation from microwave-ethanol pretreated Camellia oleifera seed shell by enzymolysis of Agrocybe aegerita

[Display omitted] •Removal rates of tannin and tea saponin in COSS were all over 85 % at 6 min MEP.•Activity of hydrolyase from A.aegerita was higher than other fungus during SSF.•Maximum activity of xylanase of A.aegerita was 213.99 U/g on day 10–12 of SSF.•Optimal conditions for OS production were 6 % substrate, initial pH 5.6, and 50 °C.•Maximum OS yield was 114.8 mg/g after 14 h enzymolysis under optimal conditions. This study aimed to produce oligosaccharide (OS) from Camellia oleifera seed shell (COSS) through the enzymolysis of edible fungus. The removal rate of tannin and tea saponin in COSS significantly increased to 85.75% and 94.51%, respectively, at 6 min of microwave-ethanol pretreatment due to the penetration and vibration damage of microwaves on the structure of COSS. The activity of hydrolyases produced from Agrocybe aegerita was higher than that from Lentinus edodes and Pleurotus ostreatus during 24 days solid-state fermentation (SSF) using pretreated COSS as the substrate. The activities of carboxymethyl cellulase, filter paper enzyme, and xylanase of A.aegerita increased to their maximum values of 94.68, 25.46, and 213.99 U/g, respectively, on days 10–12 of SSF. The optimal conditions for OS preparation via enzymatic hydrolysis were substrate concentration of 6%, initial pH of 5.6, and temperature of 50 °C. The maximum OS yield was 114.8 mg/g, which was achieved after 14 h of enzymolysis under optimal conditions. Analysis via Liquid chromatography-four-pole time-of-flight mass spectrometry revealed that the major components of OS were xylooligosaccharide and cellooligosaccharide with a polymerization degree of 2–8. Moreover, analysis of the molecular weight difference showed that no toxic byproducts existed in the hydrolysate.