| Conjugated linoleic acid (CLA), an octadecadienoic acid with conjugated doublebonds, has a variety of positional and geometric isomers. Rumiant animal and dairyproducts are among the major dietary sources of CLA. The9c,11t-18:2and t10,c12-18:2isomers are the most biologically active isomer and both them are naturallyoccurring and synthetic major isomer. CLA as a new discovered nutrients, theameliorative effects of CLA on diseases, especially closely related to metabolicsyndromes, such as anticarcinogenic, antiobesity, antidiabetic, antihypertensive andimprove immunity.Most literatures usually use linoleic acid, sunflower oil, safflower oil and otherraw materials which are expensive substrate to convert the CLA. Colza oil is one ofour country’s major edible oil. Producing the colza oil that we got the byproducts-rapeseed oil sediment. Not only we can get easily, but also it has16percent linoleic.Using the rapeseed oil sediment to converted CLA, can save the cost and protectenvironment. Used biotransformation is a hot spot, which can immobilized restingcells transformed produce CLA, not only to achieve high-density conversion, lessinterference substance reaction system, and bacterial contamination can be easilyreused single product, etc.This paper mainly use the acidophilus bacteria, combined with adsorptionimmobilization techniques, adsorpted foot resting cells to convert colza oil productCLA, CLA can not only reduce the cost of production, but also to meet the growingmarket for CLA growing demand, to use rapeseed oil sediment can save resourcesand reduce environmental pollution.In this paper, firstly we used different methods to extract rapeseed oil sedimentin the neutral fat by extraction rate and fat mass index (acid value, saponificationvalue, iodine value) to determine the optimal extraction method is the directcentrifugation, its oil extraction rate was21.76%, an acid value of24.2,saponification value of194.706, an iodine value of69.105, and analyzed by gaschromatograph, foot compound found in colza oil contains90%unsaturated fattyacids, linoleic acid is contained there in15.5%. Then through sigle-factor experiment: enzyme concentration, substrateconcentration, reaction system’s pH, reaction temperature, reaction time, table ofrevolution and the way for lipase to add, Box-Benhnken compound design andresponse surface method, the technique conditions were optimized. The optimumconditions were determined as follows factors: enzyme concentration240U/ml,substrate concentration75mg/ml, pH7.0, temperature40℃, after optimization ofrapeseed oil sediment to hydrolysis rate is26.92±0.86%. Through the contrast ofproduced CLA by hydrolyzed rapeseed oil sediment extracts and un-hydrolysed bylactobacillus acidophilus, the result is hydrolysis rapeseed oil sediment extractshigher2.95times than unhydrolysed rapeseed oil sediment.This study contrast converted CLA by the lactibacillus plantarum andlactibacillus acidophilus. The results showed that the total production of CLA bylactobacillus acidophilus is135.62μg/ml, it’s1.3times than the lactobacillusplantarum.In this paper，we studied the directly transform rapeseed oil sediment to the CLAby immobilized the lactibacillus acidophilus, through the single factor’s study todetermine the best diameter of porous ceramicas the best adsorption time, cellconcentration, temperature, pH, reaction. On this base, the three major factors wereoptimized by using Box-Benhnken central composite–orthogonal design and responsesurface methodology. The optimum conditions were determined as follows factors:temperature was39℃, pH was6.5,the reaction time was20h and the production ofCLA was226.25±0.73μg/ml.15batches of CLA direct conversion have been carriedout using the innobilized lactic acid bacteria ball. Among the10batches were higherthan120μg/ml, and the production of CLA using immobilized lactibacillusacidophilus was1.1times of which using free lactibacillus acidophilus. |
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