In situ esterification of rice bran oil with methanol and ethanol

In situ esterifications of high-acidity rice bran oil with methanol and ethanol and with sulfuric acid as catalyst were investigated. In the esterification with methanol, all free fatty acids (FFA) dissolved in methanol were interesterified within 15 min, and it was possible to obtain nearly pure methyl esters. The amount of methyl esters obtained from a given rice bran was dependent on the FFA content of the rice bran oil. In the esterification with ethanol, it was not possible to obtain pure esters as in methanol esterification, because the solubilities of oil components in ethanol were much higher than those in methanol.     

Immobilization of Lathyrus cicera Amine Oxidase on Magnetic Microparticles for Biocatalytic Applications

Amine oxidases are enzymes belonging to the class of oxidoreductases that are widespread, from bacteria to humans. The amine oxidase from Lathyrus cicera has recently appeared in the landscape of biocatalysis, showing good potential in the green synthesis of aldehydes. This enzyme catalyzes the oxidative deamination of a wide range of primary amines into the corresponding aldehydes but its use as a biocatalyst is challenging due to the possible inactivation that might occur at high product concentrations. Here, we show that the enzyme’s performance can be greatly improved by immobilization on solid supports. The best results are achieved using amino-functionalized magnetic microparticles: the immobilized enzyme retains its activity, greatly improves its thermostability (4 h at 75 °C), and can be recycled up to 8 times with a set of aromatic ethylamines. After the last reaction cycle, the overall conversion is about 90% for all tested substrates, with an aldehyde production ranging between 100 and 270 mg depending on the substrate used. As a proof concept, one of the aldehydes thus produced was successfully used for the biomimetic synthesis of a non-natural benzylisoquinoline alkaloid.     

The effects of oxygenation aeration treatment on dissipation behaviors of tricaine mesylate in carp (Cyprinus carpio) muscle and water

Tricaine mesylate (MS-222) is one of the most used anesthetics in fish. It can be absorbed by the human body via food consumption, with related detriments to human health. In this study, a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was developed for the determination of MS-222 in carp muscle and water samples using liquid chromatography-tandem mass spectrometry (LC-MS/MS). For cleanup procedure, multiplug filtration cleanup (m-PFC) method with n-Hexane delipidation was adopted. The extraction solvent, cleanup methods and sorbents were optimized. All method validation parameters were in the acceptable range. The dissipation behavior study was followed by the method development. Firstly, the anesthesia dose and time were optimized in application study. Secondly, carps were revived for different period of time with (experimental group) and without (control group) the oxygenation aeration treatment to compare the dissipation rate of MS-222. After being anesthetized for 6 h at 50 mg/L and 12 h of elimination, the concentrations of MS-222 in crap muscle and water of experimental group was lower than those of control group. After 36 h of elimination under oxygenation aeration, over 90% of MS-222 was dissipated in carp muscle. The results showed that the half-life of MS-222 in carp muscle was 6.2 h. The findings suggested that the commonly-used oxygenation aeration treatment in aquaculture production had potential effects in accelerating the dissipation of MS-222 in carp and water. In this study, three days of withdrawal period was recommended in carps after MS-222 administration under oxygenation aeration.     

How to direct the fatty acid biosynthesis towards polyhydroxyalkanoates production?

Microorganisms are believed to be a promising feedstock for the production of many by-products (lactic acid, single cell proteins, bioethanol, polyunsaturated fatty acids) that can resolve the putative problems and cover a wide range of industrial applications. Among these components, polyhydroxyalkanoates (PHA) and fatty acids (FA) are seen as typical materials for more studies and production. In fact, PHA and FA biosynthesis share the same metabolism, where (R)-3-hydroxyacyl-CoA is a common intermediate that resulted from β-oxidation. Under this directive, FA metabolism is considered as versatile pool for PHA, hence many efforts have been focussed on directing the metabolism of microorganisms for the production of one of the components in question. In fact, the choice of final product is assumed to be a balance between genetic and metabolic regulation. Thus, special attention has been paid in this review for the ongoing research on FA or PHA production and the potential metabolic routes enhancing lipid production have also been extensively discussed.     

用D—异抗坏血酸钠延长多脂鱼冻藏期的研究

多脂鱼类在冻藏条件下迅速氧化导致腐败变质。用０．１％Ｄ－异抗坏血酸钠为抗氧化剂，经不同处理以谋求最佳抗氧化协合作用。     

辅助动力装置全环形燃烧室燃烧性能试验研究

针对某型辅助动力装置全环形燃烧室开展了整机燃烧性能试验研究。采用温度耙测量全环形燃烧室出口温度分布,研究不同进口温度和油气比条件下辅助动力装置燃烧室整机燃烧性能。试验结果表明:随着进口温度和油气比的增加,燃烧室出口温度相应增加,但温度分布规律基本保持不变,出口温度分布系数(OTDF)小于0.2,径向温度分布系数(RTDF)基本小于0.1,而燃烧效率和燃烧室进出口压力损失系数增加;随着进口总温的增加,燃烧室贫油熄火油气比逐渐减少(余气系数增加),但燃烧室的贫油熄火余气系数均大于13。     

Characteristics of Uruguayan mutton tallow

Fourteen samples of Uruguayan mutton tallow available in the local market were analyzed for their composition, melting point and titer. From the results it can be concluded that Uruguayan mutton tallow contains a higher percentage of oleic acid and a lower percentage of palmitic and stearic acids than that of other countries.     

Polyunsaturated fatty glyceride syntheses by microbial lipases

The degree of glyceride syntheses by lipase TOYO (Chromobacterium viscosum) and lipase OF (Candida cylindracea) using individual free fatty acids C_18∶1, C_18∶2, C_18∶3, C_18∶4, C_20∶4, C_20∶5 and C_22∶6 were compared. Lipase TOYO incorporated each of the fatty acids into glycerol at levels of greater than 89%. Lipase OF incorporated most of the fatty acids at levels above 70% (docosahexaenoic acid incorporation was 63%). It was concluded that these two lipases are feasible for producing glycerides from unsaturated fatty acids.     

Identification of cocoa butter equivalents added to cocoa butter by fatty acid composition of the triacylglycerol sub-fractions separated by Ag+-HPLC – II –

 In a previous study the fatty acid compositions of triacylglycerol sub-fractions, separated by Ag⁺-HPLC, were studied in samples of cocoa butter, cocoa butter equivalents (CBE) and some of their mixtures. In this paper similar research is described which was carried out on three other CBE (Illexao 30–61, Illexao 30–63, Illexao 30–71). The results show the particular significance of the fully saturated sub-fraction, in which notable percentage changes in C16 : 0 and C18 : 0 contents were also detectable in the two mixtures with the lowest CBE content (5% or 15%, w/w) relative to genuine cocoa butter. Multiple regression analysis was used to verify the percentages changes of fatty acid contents in the fully saturated sub-fraction as a function of the percentage of CBE added to genuine cocoa butter. Received: 19 December 1997 / Revised version: 25 June 1998     

Electromodulation and magnetomodulation of exciton dissociation in electron donor (starburst amine) : electron acceptor (bathocuproine) system

Electric field dependencies of electromodulated photoluminescence and photocurrents as well as the magnetic field effects on photocurrents, photovoltaic characteristics, electromodulated photoluminescence and photoluminescence have been investigated in vacuum evaporated films of m-MTDATA:BCP (4,4′,4″-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine and bathocuproine) system. The electromodulation processes do remain in accordance with Onsager as well as with the Sano–Tachiya–Noolandi–Hong formalisms of electron–hole pair separation. While the electromodulated photocurrents are due to operation of both long-radius and short-radius e–h pairs, the electromodulated photoluminescence quenching is related to merely short-radius fraction of the e–h pairs involved in the exciplex creation process. The photocurrents, photovoltaic characteristics, photoluminescence and electromodulated photoluminescence are influenced by external magnetic field of the hyperfine coupling (HFC) scale which modulates the singlet–triplet intersystem crossing of long-radius e–h pairs.