Browsing by Keyword "organic solvents"
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Item Enzymic hydrolysis of animal fats in organic solvents at temperatures below their melting points(1991-05) Virto, M. D.; Lascaray, Jose Miguel; Solozabal, Rodolfo; de Renobales, Mertxe; Tecnalia Research & InnovationLipase from Candida rugosa catalyzed the hydrolysis of inedible beef tallow and pork lard (edible and inedible) in the presence of organic solvents at temperatures below the melting point of the fat. Reactions were carried out at 50% substrate with 180 lipase units per gram of fat in a two-liter reactor. In the presence of isooctane (5-10%) beef tallow yielded 94% hydrolysis in 24 hr both at 37° and 31°C. Edible pork lard yielded 97% hydrolysis under these conditions and at temperatures as low as 25°C, while inedible lard gave hydrolysis intermediate between the other two fats.Item Hydrolysis of animal fats by immobilized Candida rugosa lipase(1994-01) Virto, María D.; Agud, Isabel; Montero, Sol; Blanco, Alicia; Solozabal, Rodolfo; Lascaray, JoséM M.; Llama, María J.; Serra, Juan L.; Landeta, L. Carlos; de Renobales, Mertxe; Centros PRE-FUSION TECNALIA - (FORMER); Tecnalia Research & InnovationLipase (triacylglycerol ester hydrolase, EC 3.1.1.3) from Candida rugosa was immobilized by adsorption on a commercially available microporous polypropylene support of 200- to 400-μm particle size. A contact period of 90 min allowed the highest degrees of hydrolysis to be achieved, particularly in the second and third hydrolysis reactions. The optimal hydrolysis conditions were 0.10 kg enzyme per kilogram fat, 50% (w/v) fat, and 40°C for 24 h. The immobilized enzyme can be repeatedly used and hydrolysis degrees of 90% or higher can be achieved. Of the three animal fats studied, edible pork lard consistently yielded the highest degrees of hydrolysis (95%) in the first hydrolysis reaction and inedible beef tallow the lowest (65%). The immobilized enzyme lost its activity above 45°C. The support could be easily recovered and reused up to 5 times.Item Kinetic properties of soluble and immobilized Candida rugosa lipase(1995-02) Virto, Mar'ia D.; Agud, ISabel; Montero, Sol; Blanco, Alicia; Solozabal, Rodolfo; Lascaray, Jos'e M.; Llama, Mar'ia J.; Serra, Juan L.; Landeta, L. Carlos; De Renobales, Mertxe; Centros PRE-FUSION TECNALIA - (FORMER); Tecnalia Research & InnovationImmobilized lipase (triacylglycerol ester hydrolase, EC 3.1.1.3) from Candida rugosa has been immobilized on commercially available microporous polypropylene and used for the batch hydrolysis of different animal fats. The effect of the reaction products at concentrations similar to those obtained at 90% hydrolysis, both on soluble and immobilized lipase, was studied. Glycerol showed low inhibitory effect but oleic acid caused 50% inhibition. A mixture of free fatty acids present in the complete hydrolysis of beef tallow inhibited lipase activity more than 70%. The stability of the enzyme (both soluble and immobilized) was highest in the presence of 20% isooctane. The apparent Michaelis constant for each substrate for the soluble enzyme did not change on immobilization.