| ‘Fengdan’peony（Paeonia ostii‘Fengdan’）is a kind of wild peony p.ostii（Paeonia ostii）cultivars,seed with the characteristics of large quantity,high oil yield,strong adaptability and yield stability,mainly for the production of peony seed oil and paeonol.‘Fengdan’peony seed shell as a by-product of oil production,accounting for peony seed quality of 1/3,despite its abundant supply,due to the lack of technology and related research by processing,many peony seed coat as a waste,without effective use of them,resulting in the loss of resources and environmental pollution.Therefore,the deep processing and utilization of peony seed has important significance to improve the comprehensive utilization rate of peony seed oil by-product and its economic benefits.The extraction method of‘Fengdan’peony seed shell of total flavonoids,the extraction technology and antioxidant activity were studied.For providing new ideas for the comprehensive development and utilization of resources of peony,and providing a reference for the application of natural antioxidants in peony seed as raw material.The main results are shown as follows.（1）Water extraction,ethanol reflux extraction,acetone reflux extraction,ultrasonic assisted extraction,microwave assisted extraction and ultrasonic microwave extraction were adopted extract the total flavonoids of‘Fengdan’peony seed shell.The extraction rate and content as the index,the extraction results were compared with the analysis.And the mechanism of the higher extraction efficiency was studied by scanning electron microscopy.The results show that the extraction rate and content of the sequence of total flavonoids of different methods:acetone extraction>ethanol reflux extraction>ultrasonic microwave extraction>ultrasonic extraction>water extraction>microwave assisted extraction.Observed under the scanning electron microscope,the peony seed cell was broken most seriously after using ultrasonic microwave extraction,the porosity and depth;on the extraction efficiency,energy consumption and solvent consumption were considered and compared the use of ultrasonic assisted extraction method has better effect.（2）Flavonoids was extracted from peony seed shell by ultrasonic extraction method,and the effects of volume fraction of ethanol,solid-to-liquid ratio,ultrasonic power,extraction time and extraction temperature on yield of total flavonoids were studied by single factor experiments,Based on this,the extraction conditions were optimized by response surface methodology（RSM）.The results demonstrated that the optimum extraction conditions were obtained as follows:volume fraction of ethanol 60%,solid-to-liquid ratio 1:50g/m L,ultrasonic power 250W,extraction time 50min and extraction temperature 40℃.Under these conditions,the yield of flavonoids was 13.66%,with the relative error of 0.15%compared with the predicted value of 13.64%.（3）Infrared spectroscopy analysis was used to confer molecular structure of peony seed extractive.The functional groups in the IR spectra show that absorption peak information:the3435.63 cm-1 absorption peak of hydroxyl stretching vibration of O-H;the strong absorption peak near 2025 cm-1,the absorption peak features of Alkynes,1450-1650cm-1 for benzene skeleton characteristic absorption peak;stretching vibration peak at 1601.44 cm-1 of carbonyl C=O,some peak 1400-1200cm-1 is a carbohydrate C-H variable angle vibration absorption peak,so it can determine the compound containing carbohydrates;1159.22cm-1 is the absorption peak of phenolic hydroxyl groups,so that total flavonoids of peony seed shell may be inferred for flavonoid glycoside substance.（4）In order to antioxidant activity evaluation of flavonoids of peony seed,this experiment used three different methods:DPPH radical scavenging ability,ferrous ion chelating ability and ferric reducing ability.The results show that the total flavonoids in peony seed shell has good antioxidant activity,can effectively scavenge DPPH free radical and ferrous ion chelating and reducing iron ions,and in a certain concentration range with the flavonoids concentration increases the corresponding scavenging ability is enhanced.Compared with the same concentration of Vc under control,presented the same trend,and clear the peony seed shell flavonoids on DPPH radical was higher than that of Vc.The peony seed shell flavonoids have ferrous ion chelating ability,but lower than that of ferrous ion chelating ability of chelating agent EDTA.The peony seed shell flavonoids on iron reduction ability is lower than Vc control.In conclusion,the total flavonoids in peony seed shell have good antioxidant activity. |
PDF Full Text Request