Study On Extraction Technology Optimization And Purification Of Glucosinolates From Dry Broccoli

Glucosinolates are an glucose derivative containing sulfur which are wide spread in crucifers. Among diverse and rich glucosinolates exist in broccoli, glucoraphanin shows the best content. Sulforaphane is the mainly degradation product, which is efficient on the antitumor. Cruciferous vegetables can contribute to the prevention and treatment of cancer, which is put forward by WHO. Thus, the extraction process, enrichment and purification of glucosinolates was studied to the exploitation of health food which is essential to health.The most suitable method of enrichment and purification of Glucosinolates was investigated using dry broccoli, which could provide a theoretical basis to the exploitation and production of glucosinolates health products. The conclusions are as follows:1.Efficient extraction of glucosinolates was obtained using90% ethanol at60℃by the investigation on the single factor experiments and surface optimization test include ethanol concentration, time, ratio, times. The best condition of extraction of glucosinolates are as follows:90%ethanol,1:12of solid-liquid ratio, one hour of extraction time, four times repeated. Thus,0.6827mg/mL of crude glucosinolates extract,0.8972g of dry substance, the purity of15.22mg/g and17.94%of solid recovery was obtained.2.Ethanol precipitation was used to the study on the precipitation of glucosinolates using95%ethanol at0℃. The experimental results showed that after one hour of precipitation, precipitation recovery of glucosinolates was about90.20%, and the content was about20.40mg/g which increased about34.03%compared with unpurified glucosinolates. On the other hand, the purification of glucosinolates by CaCl2precipitation was also investigated. The results showed that41.35%of total glucosinolates could be precipitated by the formation to calcium salt. Removal of Ca2+could cause62.25%loss and the ultimate recovery of glucosinolates was about22.14%. CaCl2precipitation could avoid loss of glucosinolates in the long time of concentration step, which explored a new idea to the method of purification. Compared with the methods of the precipitation of protein like polyacrylamide, edible tannin, silica gel and Sevag, the recovery rate of glucosinolates was about89.34%by Sevag. 3.The effect of adsorption of glucosinolates was compared with several kinds of food grade column packing, the corresponding adsorption rate of Chitosan, kaolin and PVP/P is respectively7.70%,2.52%and2.80%, and the corresponding purity of glucosinolates was about19.89mg/g,18.23mg/g and16.36mg/g, which increased about30.70%,19.79%and7.50%compared with unpurified glucosinolates. While activated carbon powder, D315macroporous resin and acidic alumina could effectively adsorb glucosinolates. The recovery rate of glucosinolates could reach to41.34%,50.61%and86.72%by the best elution solution of glucose acid lactone, calcium chloride and ammonium carbonate. The adsorption saturation of activated carbon powder and acidic alumina on glucosinolates was about28mg/g and16mg/g. The best method was using kaolin and acidic alumina as column packing by comparing the effect of purification of glucosinolates. Thus,0.5815mg/mL of crude glucosinolates extract,0.0182g of dry substance,31.95mg/g of solid powder and84.62%of solid recovery was obtained, and the recovery rate of glucosinolates could reach to84.62%. The content and purity of glucosinolates was improved by this method, which could be helpful for factory production.4.The effect of glucosinolates elution could be improved by ultrasonic and centrifugal, the recovery rate could reach to84.62%compared with control group. The major of glucosinolates could be eluted by only5mL eluent. The above methods could provide a theoretical basis to further purification of glucosinolates.