Effects Of Seawater Constant Ions And Functional Drinks On Enzymatic Lipid Hydrolysi

Seawater contains a lot of minerals and trace elements.Fresh water and concentrated seawater can be obtained by seawater desalination technology.In order to reduce the pollution and realize the recycling of concentrated seawater,the concentrated seawater can be made into marine functional drink.The functional drink has the effect of reducing blood lipid and preventing abnormal lipid metabolism diseases.The development of marine functional drink not only brings new value to concentrated seawater,but also is of great significance to realize zero discharge of seawater.Firstly,the effects of marine functional drink on lipase activity and stability were investigated by detecting the change of lipase activity under different kinds and concentration of major ions(Mg²⁺、Ca²⁺、Na⁺、K⁺、B³⁺).The effects of five major ions on lipase were analyzed by multiple linear regression model.Moreover,the conformational changes of lipase were characterized by Zeta potential,UV spectrum,fluorescence spectrum and synchronous fluorescence spectrum.Based on the above results,the effects mechanism of the functional drink and its major ions on lipase were preliminarily explored.The results showed that the activity and stability of lipase were promoted by the marine functional drink and the increasing ionic concentration and species.And the influence order was Mg²⁺>K⁺>Ca²⁺>B³⁺>Na⁺.The Zeta potential of lipase molecules was changed,and the UV absorption and the fluorescence intensity were also increased under the effect of functional drink and its major ionic.Furthermore,the maximum absorption peak was red shifted by 3 nm.The result proved that the microenvironmental polarity of protein molecules was changed,which resulting in the change of electricity and hydrophilicity of amino acid residues.And then,the conformation of the lipase molecules was affected,and the lipase activity and function were improved.Secondly,the single factor experiment was used to optimize the reaction conditions of enzymatic lard hydrolysis.According to the optimization conditions,four factor and three-level orthogonal experiments were designed to obtain the optimal reaction environment.Whereafter,the effects of marine functional drink and its major ions on the initial rate and hydrolysis rate of enzymatic hydrolysis were studied.Finally,the main fatty acids components in the hydrolysis products were determined by gas chromatography-mass spectrometry,and the effects of marine functional drink and its major ions on lipase selectivity were clarified.The results showed that the initial rate and hydrolysis rate of enzymatic hydrolysis were promoted by the marine functional drink and its major ions,moreover the improved performance was positively related to ionic concentration and species.The contents of palmitic acid,palmitoleic acid,stearic acid,oleic acid and linoleic acid in enzymatic lard hydrolysis products were 23.14%,7.78%,9.44%,31.24%and 10.62%,respectively.The percentages of palmitoleic acid and linoleic acid were increased by additional the marine functional drink and its major ions.Among them,the palmitoleic acid and linoleic acid increased to 10.64%and 16.89%by additional marine functional drink,which was the most significant influence.The results showed that the marine functional drink and its major ions makes the reaction more inclined to produce unsaturated fatty acids,such as palmitoleic acid and linoleic acid.