| After the commercial forest cutting was completely stopped in Great Xing'an Mountains,the rational development and utilization of wild economic plant resources under the forest has gradually become a new local management and development idea.As an important wild and economic plant resources under the forest,lingonberry has been paid attention to its development and utilization gradually.To comprehensively understand the distribution properties,exploitation,and utilization status of lingonberry in Great Xing'an Mountains,the data collection,sorting,and analysis were carried out on the number of plants,total reserves,annual collection quantity,processing and utilization of lingonberry resources in Great Xing'an Mountains.The results showed that lingonberry resources are distributed zonally in Great Xing'an Mountains where its total reserves are large.To be specific,the lingonberry resources located in the northwest bureaus of Great Xing'an Mountains are more concentratedly distributed.The annual collection quantity of lingonberry is increasing,and the local lingonberry was mainly collected for selling as one type of fruit,which results in low economic value added and underutilization.According to the actual situation of lingonberry resources in Great Xing'an Mountains,the comprehensive utilization of lingonberry juice fermented fruit wine brewing technology,the reuse of lingonberry fruit pomace and the extraction and enrichment of active components from lingonberry leaves were studied,which provides technical reference for the follow-up in-depth development and utilization of lingonberry resources.During the brewing of lingonberry wine,the difficulty of starting fermentation was the main technical problem.We determined the comprehensive physical and chemical indexes of lingonberry such as total acid,total sugar,pH value,soluble solids,benzoic acid and total nitrogen.It was found that lingonberry is rich in acid content and poor in nitrogen content,which is the main reasons for the difficulty of starting fermentation of lingonberry fruit wine.To solve the above problems and considering the industrial production costs and implementation under real conditions,we reduced the acid content of lingonberry juice by adjusting the pH value and diluting juice,and supplemented the nitrogen content required for lingonberry wine fermentation by adding nitrogen source to promote more thorough fermentation.To guarantee the quality of lingonberry fruit wine,we obtained artesian juice after enzymatic hydrolysis for 2.0 h at 40?with 0.3‰ pectinase of lingonberry fruit quality.Taking the brix as the index,the effects of different acid-reducing treatments,yeast types and dosage,carbon source types and dosage and nitrogen source dosage on fermentation rate of lingonberry artesian juice were studied.Basis on optimizing the fermentation conditions of 2 L small-scale fruit wine in the laboratory,a set of the fermentation process of lingonberry dry-type fruit wine was explored by using a 10 L automatic fermenter,and then we developed one recipe for brewing lingonberry fruit wine.The detection results of aromatic components of lingonberry fruit wine showed that the highest aromatic component was ethanol with a relative content of 86.30%,indicating that lingonberry fruit wine was fully fermented,and other aromatic components with relatively high contents were ethyl benzoate,3-methyl-1-butanol,ethyl acetate,phenethyl alcohol and ethyl caprylate,with flower,fruit or cream aroma.To reuse lingonberry fruit pomace,which is often treated as waste,anthocyanins were extracted effectively.Due to the instability of the anthocyanin structure and considering the potential food safety hazards of traditional synthetic antioxidants in the application,rosemary extract was selected as the natural antioxidant in the ultrasound-assisted extraction of anthocyanins from lingonberry pomace.The yields of three main anthocyanins from lingonberry pomace,cyanidin-3-galactoside,cyanidin-3-glucoside,and cyanidin-3-arabinoside were measured by high-performance liquid chromatography(HPLC).We also used the single-factor experiments,the kinetic model,and response surface methodology to systematically optimize the parameters affecting the yield of anthocyanins from lingonberry pomace.Under the above-optimized conditions,the total yield of three main anthocyanins from lingonberry pomace was 4.12±0.18 mg/g.To further verify the effectiveness of the proposed method,rosemary extract was also added as an antioxidant in the extraction process of anthocyanins and flavonols from the berry plant blueberry,which is the same genus as lingonberry,it turns out the addition of natural antioxidant rosemary extract significantly improved the yields of anthocyanins and flavonols from blueberry pomace.As a natural component,rosemary extract is safer and more reliable in replacing synthetic.antioxidants.It has a great application prospect in the extraction of easily oxidized components of plant raw materials in the future.Lingonberry leaves were rich in phenols,especially arbutin,salidroside and chlorogenic acid,and the content of arbutin in lingonberry leaves is high.We used microwave pretreatment-circulated ultrasound extraction technology to extract arbutin,salidroside,and chlorogenic acid from lingonberry leaves in the meanwhile.The nine factors affecting the extraction yield were analyzed by single-factor analysis.The PBD(Plackett-Burman design),kinetic model and BBD(Box-Behnken design)were used to screen the main influencing factors.According to the results of PBD experiment,8 extraction conditions had a positive impact on the yield of three target analytes among the 9 single factors(the degree of influence in descending order was liquid-solid ratio,ultrasound irradiation time,ultrasound irradiation power,ethanol volume fraction,vaporizer concentration,vaporizer dosage,microwave irradiation time and microwave irradiation power),and one negative factor(stirring speed).BBD optimization was carried out for the three main influencing factors of liquid-solid ratio,ultrasound irradiation time and ultrasound irradiation power screened by PBD and kinetic model.Based on the optimized extraction conditions,the actual extraction yields of arbutin,salidroside and chlorogenic acid from lingonberry leaves were 14.80± 0.21 mg/g,1.23±0.04 mg/g and 0.87 ± 0.02 mg/g,respectively.To effectively enrich arbutin,salidroside,and chlorogenic acid in lingonberry leaves extract,Fe3O4@SiO2@IL(VBimBr),a type of magnetic silica gel loaded ionic liquid adsorbent materials was prepared,and Fe3O4?Fe3O4@SiO2 and Fe3O4@SiO2@IL(VBimBr)were characterized.The results showed that the ionic liquid was successfully loaded on magnetic silica gel materials.Using the prepared magnetic absorbent above,static and dynamic absorption for arbutin,salidroside,and chlorogenic acid were carried out.The results of static adsorption showed that when Fe3O4@SiO2@IL(VBimBr)magnetic adsorbent material reached equilibrium for arbutin,salidroside,and chlorogenic acid,the adsorption rates of the magnetic adsorbent materials for the three target analytes in descending order were 69.83%±1.13%of chlorogenic acid,62.13%±1.38%of arbutin,and 47.67%±1.35%of salidroside respectively.The eluent with 50%ethanol volume fraction was used to desorb the three target analytes.When the desorption equilibrium was reached,the desorption rates in descending order were 82.47%± 1.69%of chlorogenic acid,78.56%±1.12%of salidroside,and 73.64%±1.66%of arbutin,respectively.Compared with Freundlich adsorption model,the adsorption isotherms of arbutin,salidroside and chlorogenic acid were more consistent with Langmuir adsorption model,so the adsorption process of Fe3O4@SiO2@IL(VBimBr)to three target analytes in lingonberry leaves should be monolayer adsorption.A gas-liquid-solid three-phase magnetic fluidized bed was used to enrich arbutin,salidroside and chlorogenic acid dynamically.The gas phase,liquid phase and solid phase were nitrogen,lingonberry leaves extract and Fe3O4@SiO2@IL(VBimBr)magnetic adsorbent respectively.The liquid flow rate and magnetic field intensity were optimized,and the flow rate of sample loading was 6 mL/min after optimization.Under the applied magnetic field strength of 42.59 Oe,the three target analytes reached dynamic adsorption equilibrium earlier.It was speculated that the magnetic fluidized bed reached a magnetically stable state under the conditions of sample loading flow rate of 6 mL/min and magnetic field intensity of 42.59 Oe.The target analytes were desorbed with 50%ethanol eluent.The purity of arbutin,salidroside and chlorogenic acid was 42.01%,1.85%and 3.39%respectively.Fe3O4@SiO2@IL(VBimBr)magnetic adsorbent could effectively enrich arbutin,salidroside and chlorogenic acid in lingonberry leaves extract,and still have a certain enrichment ability after repeated utilization,reduced costs effectively.The dynamic enrichment process made the solid-liquid contact more sufficient and the enrichment efficiency higher under magnetic stable state.To further illustrate the fluidization characteristics of gas-liquid-solid three phases in the dynamic enrichment process of magnetic fluidized bed,the dynamic process was simulated by FLUENT software.The flow field nephogram showed that under the conditions of sample loading flow rate of 6 mL/min and magnetic field intensity of 42.59 Oe,the fluidized bed could reach a magnetically stable state,and the contact between the magnetic adsorbent and target analytes was the most sufficient.The simulation results were consistent with the actual experimental results,and the enrichment effect on the three target analytes was the best under the above conditions. |
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