Study On Extraction Separation And Microencapsulation Of Sulforaphane From Broccoli Seed

Sulforaphane(SF),a hydrolysate of Glucoraphanin(RAA)in cruciferous plants,is recognized as one of the natural products with the best anticancer and anticancer effects,so they have broad market prospects.At present,the domestic and international markets mainly use broccoli seed water extracts as the products,the main component of the extract is RAA,the content of medicinal ingredient SF is extremely low.This is due to the unstable isothiocyanate structure in the SF molecule,which can be degraded and inactivated by external temperature and oxygen,and greatly limits the development and application of SF.Microencapsulation technology can encapsulate unstable substances in polymer materials and improve their stability.In conclusion,due to the immaturity of SF preparation technology,poor stability and less research in preparation,SF related products are scarce,and it is difficult to meet the diversified needs of the market.In this paper,broccoli seeds were used as raw materials.Supercritical CO2 extraction,enzymatic hydrolysis,macroporous adsorption resin and emulsified spray drying were used to systematically study the extraction,separation,purification and microencapsulation of SF.Establish a process route from raw materials to products,with a view to promoting the development of SF in practical applications such as food,health products and pharmaceuticals,and to develop it into higher value-added products.The research content of this paper mainly includes the following three parts:1.Study on extraction process of broccoli from broccoli seedsBroccoli seeds were used as raw materials.First,the effects of seed degreasing method and hydrolysis method on the yield of SF were compared.The results were as follows:The supercritical CO2 extraction method was first applied to the degreasing process of broccoli seeds,then the broccoli seed degreasing powder was further hydrolyzed by enzymes to obtain a clearer SF extract.Secondly,the supercritical CO2 extraction process was optimized according to the oil yield of broccoli seeds.The results were as follows:pressure 30 MPa,flow rate 7 BV/h,particle size 40 meshes,extraction 4 hours at 40℃.94%of the oil in the seed can be removed.Then,the oil composition was analyzed by GC-MS.The results showed that erucic acid content in broccoli seed oil was up to 58.26%,which further indicated the necessity of degreasing broccoli seeds.Finally,the L9(34)orthogonal experimental design was used to study the enzymatic hydrolysis of broccoli seed defatted powder with SF content as the index.The optimum process parameters were as follows:extraction time was 6 h,extraction temperature was 30℃,the pH value was 6,the water addition amount was 10 BV,and finally the SF content was 5.40 mg/g.SF extraction process established in this experiment,the yield of SF was 4.16 mg/g,which was 32.48%higher than the traditional direct hydrolysis method,and the obtained SF extract was relatively clear,which was beneficial to the later enrichment and purification.2.Study on separation and purification of sulforaphaneThe macroporous adsorption resin and liquid-liquid extraction technology were used to systematically investigate the purification process of SF extract.The purification process parameters were determined as follows:DM850 macroporous resin was pretreated and packed into the column to make the column diameter ratio 1:8,SF extract was adjusted to pH 4 with 2 mol/L hydrochloric acid,centrifuged(4000 rpm,10 min),and the flow rate was 4 BV/h for 22 BV,and 0.5 h after the end of the sample.Then,it was eluted with 5 BV water,2 BV 10%ethanol,6 BV 50%ethanol,the flow rate of impurity removal and elution was 4 BV/h,and 50%ethanol eluate was collected and concentrated to SF concentration of about 3.31 mg/mL under vacuum.2 BV ethyl acetate was extracted twice,the extract was combined,and ethyl acetate was evaporated to dryness under reduced pressure.After purification of the process conditions,the average purity of SF can reach 45.01%,the total recovery rate was 72.00%,the process was stable,feasible,simple,low cost and can be used for scale-up production.The main components after purification were analyzed by GC-MS,and the results show that the SF obtained by the enzymatic hydrolysis method and macroporous adsorption resin-liquid-liquid extraction combined purification technology was green and safe,the components were clearly developed for product development.3.Study on microencapsulation of sulforaphaneThe SF microcapsules were prepared by emulsion spray drying method.The effects of wall materials,ratio of capsules,plant oil,solid content,emulsifier dosage,ratio of oil to wall material and inlet air temperature on the preparation process of microcapsules were studied.And design orthogonal test to optimize the best SF microencapsulation process.The results were;gum arabic/maltodextrin(1:1 m/m)was selected as the wall material,canola oil was the plant oil used,the solid content was 35%,the emulsifier dosage was 2%,the ratio of oil to wall material was 1:2,and the inlet air temperature was 160℃.The SF microencapsulation method was established in this experiment,the SF encapsulation efficiency was 80.59%,and can be further promoted in production.The physical properties of SF microcapsule powder were studied:SF microcapsule was in the form of off-white powder,and the special smell was masked,the water content was 4.52%,the particle size D50 was 2.29 ±0.15 μm,the scanning electron microscope showed that the most of the particles were smooth and round without cracks.The results showed that the SF microcapsule powder had good physical properties.The stability of SF microcapsule was studied:the retention rate of SF decreased with the increase of SF purity.The results showed that the purity of SF used in this experiment was suitable and stable;The stability of SF was poor under high temperature conditions,and the degradation rate constant(k)of SF decreased by 5～11 times after SF was encapsulated by microcapsule,The activation energy(Ea)increased by 14.04 kJ/mol,indicating that microencapsulation can significantly improve the tolerance of SF to temperature;The sample retention experiments showed that SF was extremely sensitive to temperature,it was suggested that SF microcapsulated products should be stored under refrigerated or frozen conditions.