Study On Extraction Of Lutein Esters And Lipase-catalyzed Synthesis Of Lutein Derivatives

Natural lutein esters is a kind of important carotenoids fatty acid esters. Its stability is better than pre-columri lutein and the bio-accessibility of lutein esters is greater than that of lutein.Lutein esters is widely used in food,health care products and drugs.The major research topics is the lutein ester was synthesized from lutein and acid which catalyzed by Lipozyme Novo 435.Microwave-assisted extraction of lutein esters from marigold was investigated. Based on the single factor experiments, the effects of different extraction temperature,extraction time,ratios of solution to solid and microwave power on the extraction yield of lutein esters from marigold were optimized with Response Surface Methodology(RSM).A mathematical model was established and analyzed to describe the relationships between the studied factors and the response of the total extraction yield of lutein esters from marigold.The optimum extraction parameters are as follows:extraction temperature 40℃,extraction time 20s,ratios of solution to solid 20 ml/g, microwave power 500W.Under the optimum conditions,the extraction rate of lutein esters from marigold can reach 14.595 mg·g-1.In this paper, lutein was achieved using lutein esters by saponification technology were systemically investigated under ultrasonically conditions.Based on the single factor experiments,the affecting factors such as the water/solid ratio (ml/g),reaction temperature and reaction time were optimized with Response Surface Methodology (RSM).The studied factors and the response of the yield of lutein were analyzed.The results showed that the optimal saponification parameter was the reaction at the water/solid ratio of 15 (ml/g),48℃and 138 min.Under the optimum conditions,the yield of lutein can reach 75.8 mg·g-1The oleic acid lutein ester was first synthesized from lutein and oleic acid, caffeic acid,gallic acid,mandelic acid,L-Alanine acid,L-Lysine acid which catalyzed by Lipozyme Novo 435,the structure were determined by IR,13CNMR, 1HNMR and MS.The effects of enzyme concentration,solvent,the ratio of water to substrates,reaction temperature and reaction time on the esterification were investigated.The optimized conditions are:enzyme concentration 10mg/ml,the ratio of water to substrates 80mg/g,solvent chloroform and reaction temperature 45℃,reaction time 30 h.The oleic acid conversion rate is up to 80.4% when the esterification is carried on under the optimal conditions;enzyme concentration 10mg/ml,the ratio of water to substrates 10mg/g,solvent chloroform and reaction temperature40℃,reaction time24h.The caffeic acid conversion rate is up to 88%;enzyme concentration 10mg/ml,the ratio of water to substrates 60mg/g,solvent chloroform and reaction temperature 40℃, reaction time 30 h.The gallic acid conversion rate is up to 81.8%;enzyme concentration 10mg/ml,the ratio of water to substrates 80mg/g,solvent chloroform and reaction temperature 40℃,reaction time 24h.The mandelic acid conversion rate is up to 77.8%;enzyme concentration 10mg/ml,the ratio of water to substrates 80mg/g,solvent chloroform and reaction temperature 40℃,reaction time 30 h.The L-Alanine acid conversion rate is up to 81.8%;enzyme concentration 10mg/ml,the ratio of water to substrates 80mg/g, solvent chloroform and reaction temperature 40℃,reaction time 30 h.The L-Lysine acid conversion rate is up to 80.4%.