Study Of Novel Sample Pretreatment Methods And Its Application In Functional Foods

With the improvement of people’s living standards and the emergence of sub-health problems,China pays more and more attention to the research and development of functional food,but there is still a certain gap compared with some foreign countries that started earlier.The extraction and analysis of active ingredients in functional food is the first step in the research and development process.However,the traditional sample pretreatment technology usually has shortcomings such as high energy consumption,long time and large use of organic solvents.This study is devoted to the development of new sample pretreatment technology with high efficiency,low energy consumption and environmental protection,and applied to the extraction and enrichment of active ingredients in functional foods.1.A solid phase matrix dispersion microextraction method assisted by boron nitride nanoparticle（BNNS）was developed for the extraction of alkaloids from functional foods.The target compounds were identified by UHPLC-Q-TOF-IM/MS.During the experiment,some important parameters,such as the type of dispersant,the amount of dispersant,the grinding time and the type of elution solvent,were optimized.Finally,BNNSs was selected as the best dispersant,and its microstructure was characterized by SEM and TEM.Due to the special properties of BNNSs,the cost of this experiment is greatly reduced,especially in terms of elution solvent volume（200μL）,sample dosage（50 mg）and extraction time（2 min）.The results showed that the method had good linearity（r²>0.999）,the recovery was 80-100%.RSDs of intra-day and intra-day accuracy were less than 2.01%and 4.84%,respectively.The LODs were 2.54-5.00 ng/mL,and the LOQs were 8.47-50.00 ng/mL.The method was successfully applied to the determination and analysis of three alkaloids in lotus plumule.2.A mechanical amorphous dispersion method assisted by polyethylene glycol（PEG）was developed for the first time to extract hydrophobic anthraquinones from functional foods.In order to fully understand the factors affecting the extraction efficiency,single factor test and RSM were used to systematically study the extraction efficiency.The influence parameters such as the type of PEG,the mass of PEG,grinding time,extraction time and solid-liquid ratio were optimized.The optimum conditions were PEG100000 242.67 mg,grinding time 4.91 min,extraction time 4.60min and water 10 mL.To verify the feasibility of the method,the extracted solution was analyzed by UHPLC-Q-TOF/MS.The results show that the method has good linearity（r²>0.99）,the RSDs of intra-day and intra-day precision were 0.04-2.07%and 0.22-3.00%,respectively.The RSD_Sof reproducibility were 0.02-6.23%.Finally,it is demonstrated that this method can be used for the extraction and analysis of seven anthraquinones from aloe.3.The mixed enzymes-assisted mechanical bio-extraction method was used for the extraction of polysaccharides from functional food.Through the process of optimization,the parameters that influence the extraction efficiency including the ratio of enzyme,the amount of enzyme,the extraction time,the grinding time and the ratio of solid/liquid were investigated.The best extraction conditions were obtained with the ratio of cellulase to pectinase was 2:1 and enzyme concentration 0.02g/mL,the grinding time of 10 min,the volume of water was 10 mL.The purified polysaccharide was characterized by GPC,SEM and FT-IR,which made the polysaccharide information more comprehensive.The obtained polysaccharide extracts were hydrolyzed and derivatized and then injected into UHPLC-Q-TOF/MS for monosaccharide composition analysis.After optimization of the chromatographic conditions（including mobile phase and column）,twelve monosaccharides were successfully determined within 20 min.The proposed method provided satisfactory linearity with the correlation coefficients higher than 0.99,suitable recoveries（81.46-114.92%）,acceptable reproducibility ranging from 0.06-4.77%,low LODs（0.70-45.45 ng/mL）.Therefore,this method can be used for the extraction of polysaccharides and the determination of monosaccharides from functional food.4.A simple,high efficiency and environmentally friendly IL-ATPSE method for multiple monosaccharides from jujube was established.The parameters affecting the enrichment effect including the type of IL,the amount of ILs,the amount of salt,the vortex time and the pH value of solution were optimized.The optimized conditions was as follows:[C₄min]Br with the amount of 313.49 mg,the amount of salt was 4.6g,the vortex time of 3.18 min,the pH value of 9.In addition,the established method was verified with good linearity（r²>0.999）,high sensitivity with the LOD were ranged from 6.1-34.09 ng/mL,LOQ in the range of 20.57-113.63 ng/mL.The recoveries of spiked samples were in range of 87.21-104.83%.Finally,the established method was successfully applied for the extraction and enrichment of multiple monosaccharides compounds from jujube.