Large Scale Production And Detection Of Natural Taurine From Abalone Viscera

With the increasement of health consciousness and living standards,people have more and more demand for “natural” foods.The natural taurine is extracted from organisms of plants and animals(mainly aquatic animals).Compared with synthetic taurine,the natural one is more safer and has considerable market prospect.Using abalone viscera as raw materials,single factor and response surface method(RSM)combining 4 factors of extraction temperature,extraction time,liquid-to-solid ratio,extraction times and their interaction effects on the extraction efficacy of taurine were investigated.A mathematical regression model was established based on the effect of each factor and taurine extraction.Optimal extraction conditions were determined as following: temperature at 94 °C,extraction time for 140 min,liquid-to-solid ratio of 4:1,extraction for 4 times.Under these conditions,the extraction rate of taurine from boiled liquid of abalone viscera was(12.82±0.23)mg?g-1,which agreed well with the predicted value of 13.00 mg?g-1 from the regression model.This result indicated that the regression model could fit well with the actual situation.Natural taurine with high purity was extracted from 10 kg abalone visceral under the optimum water extraction conditions,and separated by combination of ceramic and ultrafiltration membranes,concentration,ethanol precipitation,crystallization and recrystallization.High pressure liquid chromatography was used to analyze the purity of taurine.The results showed that the loss ratio of taurine was 25.61% using 0.2 ?m ceramic membrane and 100 kDa ultrafiltration membrane.After two membrane separation,concentration,ethanol precipitation and crystallization,35.63 g natural taurine with purity of 83% was finally obtained from 10 kg abalone visceral,and the purity could be improved to 98.3% after recrystallization.Compared with the traditional method of preparation of natural taurine,the way without using ion exchange resin was simpler,with lower cost and more suitable for large-scale production.Scanning electron microscopy(SEM)assay of natural taurine and synthetic taurine crystal showed that the shape of the natural taurine crystal is crystal powder of fine acicular,the surface is rough and it has more grain adhesion;the shape of synthetic taurine crystal is stick,it has smooth surface and less grain adhesion.The difference in the crystal form may be caused by the different crystallization.The results of the vitro antioxidant activity showed that natural taurine and synthetic taurine in vitro do not have obvious antioxidant capacity,impling that the antioxidant capacity of taurine in vivo is due to its synergistic effect.The acute toxicity of natural taurine showed that its LD50 value was higher than 10 g?kg-1.This indicates that natural taurine extracted from abalone visceral was actually non-toxic or non-toxic substance,and its safety was guaranteed.Finally,a method for identification of natural taurine and systhetic taurine was established.According to the 14 C activity of natural taurine was higher than that of the synthetic one,the 14 C activity was measured with Ultra-low background liquid scintillation analyzer.The results showed that the CPM value of instrumental background was 1.9,the CPM value of synthetic taurine was 1.8,while the CPM value of natural taurine solution was 2.7 under same concentration(50 mg?mL-1),and by entrusting a third party testing center to verify the experiment.This result indicated that the 14 C activity measurement method can effectively distinguish natural taurine and synthetic one,which is of practical significance for the protection and supervision of natural taurine market.