Analysis And Preparation Of Cyclolinopeptides In Flaxseed Meal Based On Dry Screening

Flaxseed is one of the important oilseed crops in China,with various valuable effects on human being.With public acceptance of“Eat less oil,Eat better oil”,the demand on flaxseed oil is increasing in recent decades.Flaxseed meal,as the major byproduct of screw-pressing,is the resources for some of the flaxseed nutrient such as lignan and cyclolinopeptides.However,current utilization of flaxseed meal still remains in a primitive stage,like feeds or direct discard.Through physical screening,the complexity of extracting nutrients from flaxseed meal could be greatly reduced.Besides,the obtained kernel fraction from flaxseed meal could serve as an ideal feedstock for cyclolinopeptide production.In the present study,critical segment like meal powder screening,detection and preparation of cyclolinopeptides from flaxseed meal were investigated,providing a practical method on producing cyclolinopeptide from flaxseed meal.The founding of this research could also provide experimental basis for green extraction and value-added production.The main contents of this research are as followed:(1)Dry screening method with different mash(60,80,and 100)was applied in post-dehulling of flaxseed meal.The characterization of obtained fraction was conducted via SEM(Scanning Electron Microscope),EDS(Energy Dispersive Spectrometer),SPX(X-ray photoelectron spectroscopy),FTIR(Fourier Transform Infra Red)and FHSI(Fluorescence Hyperspectral Imaging)methods.Through SME method,shape of flaxseed meal shells(80 mesh)seems dried and stacked together,while flaxseed meal kernels show the smoothness of the oil,indicating that the composition of different parts of flaxseed meal composition characteristics are significantly different.Both semi-quantitative EDS energy spectroscopy and XPS methods showed that the flaxseed meal shell components includes five elements:C,O,K,Mg,Ca,additional Mg and Ca elements was found in flaxseed meal kernel.The results show that:the method can achieve the effective separation of flaxseed meal shells,kernels,with advantages of simple,practical,high recovery rate,high feasibility,which is suitable for industrial production.A 6:4 separation ratio of flaxseed meal husk kernel under 80 mesh sieving can ensure both meal kernel yield and efficiency,which can be a suitable raw material for the extraction of cyclolinopeptides in flaxseed meal.(2)A fast HPLC method for cyclolinopeptide analysis was developed based on14 mixed cyclolinopeptides standards.Kinetex~?Phenyl-Hexyl LC Column(150×4.6mm,2.6?m)with optimum conditions:elution programming of acetonitrile volume fraction increasing from 40%to 90%at 5%/min,flow rate 1m L/min,injection volume5?L.Under above conditions,the average resolution of the cyclolinopeptide is 1.65,and the analysis efficiency is 10.86.The time for each analysis is shortened to 9.09min,which greatly improves the analysis efficiency of the cyclolinopeptides.Compared with reported studies,the proposed methods have advantages of fast analysis and no overlapping of peaks,indicating the developed method is suitable for cyclolinopeptides analysis.(3)A two-step extraction method was developed for preparation of cyclolinopeptides using flaxseed meal as feedstock.By comparing four solvent for pre-extraction,extraction rate of crude oil,cyclolinopeptide and the corresponding oxidative index were determined using flaxseed meal fraction(from 80 mash).The pre-extraction rate of crude oil from high to low are 95%ethanol,petroleum ether,acetone and industrial hexane.The extraction rate of cyclolinopeptide are(from high to low):acetone,95%ethanol,industrial hexane and petroleum ether.The optimum extraction condition using 95%ethanol are:ratio of flaxseed meal to ethanol 1:14,extraction time 1 h,extraction temperature 70?.Under above conditions,the extraction rate of crude oil is 19.30%.By comparing and optimizing reported method for cyclolinopeptide extraction,including direction and binary phase extraction,the optimized cyclolinopeptide extraction conditions are crude oil 2 g,addition of methanol/water solution 4 m L,and vortex for 5 min.By collecting supernatant from three extraction.and filtering through wet filter paper,the extraction rate,yield of cyclolinopeptide and methionine concentration are 0.29%,96.29%and86.45%,respectively.Above result suggests that the proposed two-step extraction method with flaxseed meal through 80 mash screens as feedstock,is with advantages of green,practical and efficient,which could serve as potential method for preparing cyclolinopeptide from flaxseed meal.