Dietary polyphenolic compounds mediate polynomial actions in guarding against multiple diseases. Atherosclerosis is an oxidative stress driven pathophysiological complication where free radical induced oxidative modification of low density lipoprotein (LDL) plays the ground breaking role. Mushrooms have been highly regarded for possessing an antioxidant arsenal. Polyphenolic compounds present in dietary mushrooms seem pertinent in withstanding LDL oxidation en route to controlling atherosclerosis. In this study, the antioxidative effect of five solvent fractions consisting of methanol : dichloromethane (M : DCM), hexane (HEX), dichloromethane (DCM), ethyl acetate (EA), and aqueous residue (AQ) of Flammulina velutipes was evaluated. M : DCM fraction showed the most potent 2,2-diphenyl-1-picrylhydrazyl radical scavenging effect with IC50 of 0.86 mg/mL and total phenolic content of 56.36 gallic acid equivalent/g fraction. In LDL oxidation inhibitory tests, M : DCM fraction at 1 µg/mL concentration mostly lengthened the lag time (125 mins) of conjugated diene formation and inhibited the formation of thiobarbituric acid reactive substances (48.71%, at 1 mg/mL concentration). LC-MS/MS analyses of M : DCM fraction identified the presence of polyphenolic substances protocatechuic acid, p-coumaric, and ellagic acid. These chain-breaking polyphenolics might impart the antioxidative effects of F. velutipes. Thus, mushroom-based dietary polyphenolic compounds might be implicated in slowing down the progression of atherosclerosis.
This study aimed to investigate the effect of in vitro digestion on the antioxidant activity and carbohydrate-digestive enzymes inhibitory potential of five edible mushrooms after subjected to four domestic cooking; namely, boiling, microwaving, steaming and pressure-cooking. The water extracts of raw (uncooked), cooked and in vitro digested mushrooms were compared for their water-soluble phenolic content (WPC), total flavonoid content (TFC), ferric reducing antioxidant power (FRAP), radical scavenging activity (TEAC and DPPH), anti-α-amylase and anti-α-glucosidase activities. Among the raw samples, Lentinula edodes possessed the highest antioxidant activities (FRAP, TEAC, DPPH) and WPC while Pleurotus sajor-caju displayed the highest TFC, anti-α-amylase and anti-α-glucosidase activities. The antioxidant and carbohydrate-digestive enzyme inhibitory activities significantly varied according to mushroom species and cooking methods applied. Short duration of microwaving (Agaricus bisporus and Flammulina velutipes), boiling (Auricularia polytricha) and pressure cooking (L. edodes and P. sajor-caju) yielded the best antioxidant and carbohydrate-digestive enzymes inhibition values in the mushroom extracts. TFC was positively correlated with the antioxidant activities and anti-α-glucosidase activity in the mushroom extracts. In vitro digestion significantly improved the total antioxidant and anti-α-glucosidase activities but decreased the anti-α-amylase activity in the cooked mushroom extracts. Principle component analysis showed that in vitro digestion and the cooking process accounted for respective 48.9% and 19.7% of variation in the observed activities. Domestic cooking and in vitro digestion could potentiate the total antioxidant and carbohydrate-digestive enzymes inhibitory activities in the selected water extract of edible mushrooms.
This study aimed to investigate the effect of four cooking methods with different durations on the in vitro antioxidant activities of five edible mushrooms, namely Agaricus bisporus, Flammulina velutipes, Lentinula edodes, Pleurotus ostreatus and Pleurotus eryngii. Among the raw samples, A. bisporus showed the highest total antioxidant activity (reducing power and radical scavenging), total flavonoid, ascorbic acid and water soluble phenolic contents. Short-duration steam cooking (3 min) increased the total flavonoid and ascorbic acid while prolonged pressure cooking (15 min) reduced the water soluble phenolic content in the mushrooms. The retention of antioxidant value in the mushrooms varied with the variety of mushroom after the cooking process. The cooking duration significantly affected the ascorbic acid in the mushrooms regardless of cooking method. To achieve the best antioxidant values, steam cooking was preferred for F. velutipes (1.5 min), P. ostreatus (4.5 min) and L. edodes (4.5 min) while microwave cooking for 1.5 min was a better choice for A. bisporus. Pressure cooked P. eryngii showed the best overall antioxidant value among the cooked samples. Optimised cooking method including pressure cooking could increase the antioxidant values in the edible mushrooms.