Immobilization Of TTL Lipase And Its Application In Preparation Of LML Structure Lipid

Oils and fats is one of the indispensable raw material of daily food,endowed with good taste and nutrition of food.But as diet and lifestyle changes,in recent years due to excessive intake of the grease of diseases such as obesity has become a global problem affect human health.Therefore,the research and development can replace daily edible oils and does not cause fat in the body health of excessive accumulation of fat people become increasingly concerned research topic.LML-meddium-and long-chain triacylglycerol(LML-MLCT),it is to point to Sn-2 for the medium chain fatty acid,Sn-1,3 for a class of long chain fatty acid triglycerides.Can not only avoid the chain structure of halloysite,MLM type structure can not provide the body with unsaturated fatty acids and essential fatty acids,can be controlled by its special metabolic pathway in the human body to reduce the accumulation of fat in the body.At present the study of synthesis LML type structure fat is less,and reported by the commercialization of lipase Novozyme 435 and Lipozyme RM IM as catalyst,and Novozyme435 no position selectivity at no-solvent system,leads to the target product yield is low;Lipozyme RM IM immobilized carrier used for phenolic resin,can reduce oil product quality.TTL is one of the newly discovered in recent years from Talaromyces thermophilus lipase,approved by the laboratory study found that the TTL has strong sn-1,3 a selective,this feature is suitable for catalytic preparation of structure lipid.This study to the immobilized lipase TTL,and by using immobilized TTL as catalyst,under pressure,solvent-free system type catalytic transesterification reaction preparation LML structure fat;In addition,using the structure of the molecular distillation and purification,preparation of fat,and with the preparation of the structure of the fat as frying oil,frying experiments,the fat the physical and chemical properties of the structure are analyzed for the first time.The main results were as follows:1.After screening for kinds of carriers used to immobilize TTL lipase,AB-8macroporous resin was selected as the best one.The biggest lipase activity was obtainedunder the optimal conditions: buffer was pH 7.0,adsorbent temperature was 35?,enzyme loading was 20 mg/g resin,adsorbent time was 8 h.The FT-IR test further confirmed that TTL lipase was successfully immobilized on AB-8 macroporous resin.The optimal conditions of immobilized lipase of TTL were 60? and pH 7.0.The thermostability of TTL lipase was effectively enhanced by immobilization.The results of regio-and stereo-selectivity indicated that TTL lipase was a sn-1,3 specific lipase.2.The LML-meddium-and long-chain triacylglycerol(LML-MLCT)was prepared trough transesterification reaction by immobilized TLL.The effects of reaction temperature,enzyme loading and molar ratio of substrates on traesterifiction reaction were evaluated.The optimal reaction conditions were that temperature was 60?,enzyme loading was 6% of substrates content and the molar ratio of tricaprylin to ethyl palmitate was 1:6.The conversion of ethyl palmitate was obtained 53.31% and the content of the structure lipid contained double long chain fatty acid was 56.12% under the optimal condition.Besides,the scale transesterification reaction of tricaprylin and soybean oil ethyl ester was studied under this condition.The results indicated that the esterification rate of long chain fatty acid was not affected.The product of the scale reaction was separated by two series of molecular distillation.The content of double long chain structure lipid was 87.58% in final product,and 87.04% of caprylic acid was in the sn-2 position of structure lipid.3.To investigate physicochemical property of LML structure lipid,frying potato chips by it was selected as mode process,the physicochemical property of LML structure lipid at specific time was determined.It was found that the acid value was increased from 0.18 mg/g to 0.76 mg/g after frying 8 h and the content of trans fatty acid has not significantly effect.These results indicated that it was potential to use LML structure lipid as fried oil.The oxidation stability of LML structure lipid was analyzed,it was found that TBHQ antioxidant can effectively inhibit its oxidation.