Wax esters are long chain esters that are derived from long chain fatty acids and long chain alcohols with chain lengths of 12 carbons or more. The compounds have many potential applications. The present work focuses on the synthesis of wax esters by alcoholysis of palm oil with oleyl alcohol using Lipozyme. The effects of various reaction parameters such as reaction time, temperature, amount of enzyme, molar ratio of substrates, various organic solvents and initial water activity (aw) of the reaction system were investigated. The optimum condition to produce wax ester were respectively, incubation time, 5 h-7 h, temperature, 40°C-50°C, amount of enzyme, 1.5% (w/v) and molar ratio of oleyl alcohol to palm oil, 3:1. Hexane was the best solvent for this reaction. Analysis of the yield of the products at optimum condition showed that between 78-83% wax esters were produced.
The mixture of beef tallow with rapeseed oil (1:3, w/w) was interesterified using sodium metoxide or immobilized lipases from Rhizomucor miehei (Lipozyme IM) and from Candida antarctica (Novozym 435) as the catalysts. The chemical interesterifications were carried out at 60 and 90°C for 0.5 and 1.5 h using 0.4, 0.6 and 1.0% of CH3ONa. Depend on the catalyst used the enzymatic interesterifications were carried out at 60°C for 8 h (Lipozyme IM) or at 80°C for 4 h (Novozym 435). The catalyst doses were kept constant (8%) but the water content in catalysts was changed in the range of 2 to 10%. The starting mixture and the products of interesterifications were quantitatively separated into pure triacylglycerols and non-triacylglycerols fraction containing free fatty acids and mono- and diacylglycerols. It has been found that after interesterification the concentrations of free fatty acids and partial acylglycerols increased. On the other hand the slip melting temperatures and solid fat contents in triacylglycerols isolated from interesterified fats and their oxidative stability were lower if compared with noninteresterified, initial blend. It was interpreted on the base of alteration on molecular structure of triacylglycerols as confirmed by their sn-2 and sn-1,3 distribution of fatty acids before and after interesterification. These distributions were practically random after chemical interesterification and close to random when Novozym 435 was applied. When Lipozyme IM was used the fatty acids composition at sn-2 position remained practically unchanged if compared with starting blend.
The titled assessment was conducted using a quartz crystal microbalance (QCM) and the Langmuir-Blodgett (LB) method. The gold electrodes of QCM were coated with cellulose acetate, nylon 6 or polyethylene film by spin-coating. Spreading monolayers of long-chain fatty acid as oily contaminants on water were transferred onto spin-coated polymer film. LB films of arachidic acid were ultrasonically cleaned in aqueous solution. Detergency was determined based on the frequency change of the QCM due to cleaning. Detergency was greatest for cellulose acetate, followed by nylon 6 and polyethylene. For all films, detergency increased with the addition of ethanol, surfactant and alkali. Detergency is discussed in relation to contact angle of aqueous solution on polymer film. Liquid introduction between LB film and the polymer surface in the zone of contact appeared to be a significant factor in the removal of LB film from the polymer surface.
Medium chain glycerides (MCGs) containing C8:0 and C10:0 fatty acids have got commercial importance by considering their medicinal and nutritional applications. Monolaurin is also a value added commercial product. Coconut acid oil, which is mainly utilized in soap manufacturing process, can be effectively utilized to produce MCGs and monolaurin by a combination of lipase-catalyzed hydrolysis and esterification. Coconut acid oil containing 68% free fatty acid (as lauric acid), and 31.4% neutral glycerides are hydrolyzed by Candida rugosa lipase. The hydrolyzed acid oil was then subjected to steam distillation under atmospheric pressure to get a fraction (yield, 5%) rich in medium chain fatty acids (C8:0, 46.2%, C10:0, 19.2%), and the residual fraction was fractionally distilled under vacuum to get a fraction rich in lauric acid (68.4%). These two fractions were esterified with glycerol with Rhizomucor miehei (Lipozyme RM IM) lipase to produce MCGs from the first fraction and monolaurin from the second fraction.
In the present study, examination was made of the apoptosis-inducing activity of sphingoid bases from plant and fungus sphingolipids and the mechanisms involved. Sphingoid bases from maize and lactic yeast, Kluyveromyces lactis (trans-4, trans-8-sphingadienine, trans-4, cis-8-sphingadienine and 9-methyl-trans-4, trans-8-sphingadienine) were found to bring about apoptosis in Caco-2 human colon cancer cells. The apoptosis-inducing activity of trans-4, cis-8-sphingadienine and 9-methyl-trans-4, trans-8-sphingadienine was significantly higher than that of trans-4-sphingenine. In differentiated Caco-2 cells, the model for normal intestine cells, no apoptosis by sphingoid bases was noted to occur. The Caspase-3 inhibitor suppressed sphingoid base-induced apoptosis in Caco-2 cells, thus indicating activation of the caspase pathway to be related to sphingoid base-induced apoptosis in Caco-2 cells. Sphingoid bases from plants and fungi caused intracellular β-catenin content to decrease, as was also noted in the case of sphingosine and sphinganine from animal tissues. It would thus appear that sphingolipids in edible plants and fungi may be considered functional lipids and the apoptosis-inducing pathway by sphingoid bases may be related to signal transduction via β-catenin.
Periploca sepium is used in Chinese crude drugs and widely employed as a tonic. The volatiles obtained by steam distillation (yield, 0.10%) included 4-methoxysalicylaldehyde (87.8%), furfural (3.13%), and lavender lactone (0.77%) as the major components.
Postprandial blood triglyceride is believed to be a risk factor for coronary artery disease. In this study, rats were fed a fat emulsion orally to study the effect of daily diet on postprandial blood triglyceride. First, rats were fed different volumes of dairy cream or corn oil emulsions. The resulting serum triglyceride levels were influenced by time and dose. Second, the maintenance diet for rats was switched to a high-fat or a low-fat diet, and an oral fat tolerance test was conducted. A few days of high-fat feeding hastened the peak of serum triglyceride after administration. Two weeks of high-fat feeding elevated basal serum triglyceride, and the peak of postprandial triglyceride was submerged. The short- and medium-term fat content of the daily diet clearly affects the results of a fat loading test.