Application Of Enzymatic Hydrolysis Technology In Extraction Of Marine Fatty Acids And Heparin

Enzymatic hydrolysis is an important technology in the extraction of natural active substances, which is more energy saving and emission reduction compared with traditional methods such as alkaline hydrolysis, acid hydrolysis and salt hydrolysis. In this paper, the extraction process of tuna cod liver oil by enzymatic hydrolysis, the extraction process of Antarctic krill oil by composite enzymatic hydrolysis of papain and autolytic enzyme, and the extraction process of heparin by immobilized enzyme were studied. The main contents as follows:1) Extraction process of cod liver oil using papain enzymolysis was optimizated according to the content of Eicosapentaenoic acid(EPA) and Docosahexaenoic acid(DHA). One-factor-at-a-time experiments followed by response surface analysis was carried out to achieve the optimal extraction conditions as below: at a solid-liquid ratio of 1∶1.5 g/mL, pH 6.0, hydrolysis 2.4 hours, temperature of 41 and enzyme dosage of 0.5%. ℃Under the optimal conditions, the total content of EPA and DHA in the liver oil is up to 56.07%.2) In this manuscript, papain enzymolysis was used to extract Antarctic krill oil, and the role of autolyzed system in the Antarctic krill oil extraction process was evaluated. The results showed that krill autolysis was beneficial for Antarctic krill oil extraction, and autolytic system combined with papain could work together to achieve the best extraction results. The content of EPA and DHA in shrimp oil was investigated with respect to extraction parameters such as enzymatic hydrolysis temperature, solid-liquid ratio, enzyme dosage, hydrolysis time and pH. One-factor-at-a-time experiments followed by orthogonal test analysis was carried out to achieve the optimal extraction conditions below: at a temperature of 50 ℃, solid-liquid ratio of 1∶22 g/mL, enzyme dosage of 1.25%, pH 7.0 hydrolysis 2 hours. Under the optimal conditions, the total content of EPA and DHA in the shrimp oil is up to 75.77%.3) The preparation of immobilized trypsin and its enzymolysis effects on intestinal mucosa were investigated. The results showed the optimal conditions for immobilized as below: the mass ratio of trypsin and carrier was 1∶25, immobilized 2 hours at room temperature with 15±5 nm Si O2 as carrier. The stability of immobilized trypsin was similar with free trypsin in different temperatures, while immobilized trypsin was more stable in wider pH value. For immobilized trypsin and free trypsin, the optimum extraction conditions and extraction efficiency were similar. One-factor-at-a-time experiments followed by RSM test analysis was carried out to achieve the optimal extraction conditions from pig intestinal mucosa extraction heparin with immobilized trypsin as below: at a temperature of 46 ℃, material-to-liquid ratio of 1∶3.3 g/mL, enzyme dosage of 0.24%, pH 11 hydrolysis 5 hours. Under the optimal conditions, the heparin titer was 15.28 U. Furthermore, pH and hydrolysis temperature influence on the heparin extract very significantly, while enzyme dosage and solid-liquid extraction ratio effect on heparin significantly.