Microwave-assisted Extraction Of Flavonoids From Phyllostachys Pubescens Leaves And Its Application In Nuts

Phyllostachys edulis,a monocotyledonous family of Bambusoideae,widely distributed in China,especially in the south of the Yangtze river,is the bamboo species with the highest economic value among the existing bamboo resources in China.The resource of Phyllostachys edulis is abundant,its planting area is accounting for more than 70% of the total area of bamboo forests in China.At present,the development and utilization of Phyllostachys edulis in China are mainly used in furniture making,architecture,paper making,arts and crafts,and daily food such as bamboo shoots,etc.,but the development and utilization of Phyllostachys edulis leaves relatively lag behind,people would often treat them as waste or burned directly as fertilizer,thus affecting the overall development and utilization of Phyllostachys pubescents,thus influence the overall development and utilization of Phyllostachys edulis.Microwave-assisted extraction of flavonoids from Phyllostachys edulis leaves was studied and optimized in this paper.Taking ascorbic acid as reference,the antioxidant capacity of flavonoids from Phyllostachys edulis in vitro was investigated.Using gallic acid(hereinafter referred to as PG)and BHT as control,the inhibition of soybean oil,canola oil and sesame oil by flavonoids from Phyllostachys edulis leaves was studied.Finally,the flavonoids from Phyllostachys edulis leaves were used as natural antioxidants in Walnut,Pecan and Macadamia,so as to provide a new development idea for antioxidant and shelf-life extension of nuts.Through experimental research,the following conclusions are obtained:(1)Using the method of microwave assisted extraction to extract Phyllostachys edulis leaves flavone,by single factor test,filter affected Phyllostachys edulis leaves flavone gain rate of four factors: ethanol concentration,solid-liquid ratio,microwave power,microwave irradiation time,through the response surface optimization analysis software,and properly adjust,the research obtains the best of microwave assisted Phyllostachys edulis leaves flavone extraction process parameters: ethanol concentration 70%,the ratio of liquor to materia29:1,microwave power 303 W,microwave radiation time 300 s,with these conditions the extraction rate of Phyllostachys edulis leaves flavone could be 1.93%.(2)The flavonoids from Phyllostachys edulis leaves could scavenge superoxide anions,hydroxyl free radicals and hydrogen peroxide,and flavonoids in Phyllostachys edulis leaves have weaker scavenging ability on superoxide anions and hydroxyl free radicals than VC,while stronger scavenging ability on hydrogen peroxide than VC.(3)Flavonoids from Phyllostachys edulis leaves have antioxidant ability tosoybean oil,canola oil and sesame oil,and their antioxidant effect is stronger than VC,which is close to PG and BHT.The degree to which Phyllostachys edulis leaves inhibit the antioxidant activity of these three vegetable oils is: soybean oil?canola oil?sesame oil.(4)The flavonoids of Phyllostachys edulis leaves were used as natural antioxidants in the preparation of ripe nuts of walnut,pecan and macadamia nuts.With the acid value and peroxide value was determined,it showed that the inhibitory effect of Phyllostachys edulis leaves flavonoids on rancidity and resist oxidation of the three kinds of nuts as follows: pecan nut?walnut?macadamia nut.