摘要
研究了水解胶原蛋白在H2O2和L- 抗坏血酸协同作用下,加热氧化并生成CaSO4的机理。实验结果表明,H2O2、L- 抗坏血酸、反应温度及pH值对水解胶原蛋白中的SO2浓度都有显著影响。游离的Met在高于65℃、4min即可被H2O2和L 抗坏血酸协同氧化产生SO2。在 75℃、V(水解胶原蛋白)∶V(H2O2 )∶m(L 抗坏血酸) =100 (mL)∶5 (mL)∶1 (g)时,水解胶原蛋白中SO2浓度在 20 min内可从 5 .13×10-3 g/mL降至0 .1×10-3 g/mL,在 60min时再次上升到 3 .46×10-3 g/mL。表明了水解胶原蛋白热氧化产生CaSO4的机理是:在酸性条件下,H2O2和L 抗坏血酸作用形成L 抗坏血酸过酸,后者氧化水解胶原蛋白中的HSO-3 、—S—S—和CH3—S—,最终生成SO2-4 。导致CaSO4沉淀的生成。
Thermal oxidation of hydrolytic collagen and the mechanism of CaSO_4 format ion in the presence of both L-ascorbic acid and H_2O_2 have been investigated. The results show that the SO_2 content in the protein is af fected by L-ascorbic acid, H_2O_2, temperature and pH of the re action system. In the presence of L-ascorbic acid and H_2O_2, fre e Met could be oxidized, giving SO_2 within 4 min when temperature is above 65 ℃. At a ratio of V(hydrolytic collagen)∶V(H_2O_2 )∶m(L-ascorbic acid)=100∶5∶1 and 75 ℃ , the concentration of SO_2 in hydrolytic collagen is decreased from 5.13 ×10-3 g/mL to 0.1×10-3 g/mL within 20 min, and is then increase d to 3.46×10-3 g/mL at 60 min. Thus, the mechanism of CaSO_4 formati on could be considered as follows. Under acid condition, H_2O_2 at first react s with L-ascorbic acid, giving peroxy ascorbic acid, the latter then oxidiz es HSO-_3, —S—S— and CH_3—S— in the hydrolytic collagen, giving SO2 -_4 at last, resulting to the formation of CaSO_4 precipitate if there is Ca 2+ in the system.
出处
《应用化学》
CAS
CSCD
北大核心
2005年第3期326-330,共5页
Chinese Journal of Applied Chemistry
