Optimization of distilled monoglycerides production

Monoglycerides (MG) are emulsifiers widely used in food and pharmaceutical industries. Current industrial processes for MG production consist of the interesterification of triglycerides with glycerol (GL), in the presence of inorganic catalysts at high temperatures (>200°C). This reaction is known as glycerolysis and produces a mixture of approx 50% of MG. This level of concentration is suitable for many applications, although, for some specific uses like margarine, shortening, icing, and cream filling, require distilled MGs, which are purified MG (min. 90%) obtained by the molecular distillation process. Therefore, in this work, a 2³ factorial design was employed to evaluate the effects of reaction parameters in the MG content after the interesterification reaction of refined soybean oil with GL in the presence of sodium hydroxide as catalyst. After that, the MG content in the reaction product was enhanced through the molecular distillation process in order to obtain distilled MG.     

Kinetics of ultrasound-assisted lipase-catalyzed glycerolysis of olive oil in solvent-free system

This work reports experimental kinetic data of solvent-free glycerolysis of olive oil using a commercial immobilized lipase (Novozym 435) under the influence of ultrasound irradiation. The experiments were performed in a mechanically stirred reactor under ultrasound irradiation, evaluating the effects of temperature (50-70 °C), enzyme concentration (2.5-10 wt%) and glycerol to oil molar ratio (0.8:1-3:1). Results show that ultrasound-assisted lipase-catalyzed glycerolysis might be a potential alternative route to conventional methods, as high contents of reaction products, especially monoglycerides, were achieved at mild irradiation power supply (∼130 W) and temperature, in a relatively short reaction time (2 h) and low enzyme content (7.5 wt%). To completeness, two simplified kinetic modeling approaches, based on the ordered-sequential bi bi mechanism and reaction stoichiometry, were employed to represent the experimental data, thus allowing a better understanding of the reaction kinetics.     

均相介质中脂肪酶催化沙丁鱼油甘油解反应的动力学研究

多不饱和脂肪酸(PUFAs)的生产多集中在酶催化,与无机催化相比,酶催化具有定向性和更温和的反应条件,因而酶催化制取多不饱和脂肪酸的路线在最近几年引起人们极大的兴趣。本文以优化量的叔丁醇为有机溶剂,研究了脂肪酶Lipozymeò435催化沙丁鱼油甘油解反应生成PUFA (多以甘油一酯或二酯(DAGs, MAGs)的形式存在)。首先分析了反应系统的传质影响,考察了脂肪酶载量、温度和进料浓度等因素的影响。采用一个基于甘油酯甘油解和水解这对可逆基元反应的半经验动力学模型,成功地关联了实验的动力学数据。结果表明,温度为323 K,甘油与油的摩尔比为3：1时,生成的MAG可达84 wt%以上。还考察了其他甘油解体系,并在MAG收率、反应速率和动力学参数意义等方面进行了比较。     

无溶剂体系中脂肪酶催化合成单甘酯的研究

以自制铜绿假单胞菌脂肪酶为催化剂,通过无溶剂法棕榈油甘油解反应催化合成了单脂肪酸甘油酯,实验结果表明：适宜加酶量为500u/g棕榈 油,甘油相适宜水含量为3％－4．5％,适宜加酶量为500u/g棕榈油,甘油与棕榈油的摩尔比为（2．0－2．5）：1,最佳反应温度为38－42度,在此温度区间内适宜反应时间为24h,临界反应温度为44度,程序降温和批次加酶更有利于反应,产物中单甘酯含量可增大10－20％,实验条件下反应48h后单甘酯含量可达65％,脱酶后达77％。