混合脂肪酸的分离

以一般油脂加工副产物十八碳混合脂肪酸为原料,采用配合结晶梯度冷冻反萃取分离技术,不经任何热处理以避免聚合作用的发生,使混合脂肪酸中的饱和脂肪酸与不饱和脂肪酸分离,同时将不饱和脂肪酸分成油酸和(亚油酸+亚麻酸)两组分。后者含量可达95%以上。     

Microbial Conversion of Vegetable Oil to Rare Unsaturated Fatty Acids and Fatty Alcohols by an <Emphasis Type="Italic">Aeromonas hydrophila</Emphasis> Isolate

We isolated two new microorganisms capable of converting vegetable oil to several rare unsaturated fatty acids and rare unsaturated fatty alcohols from a soil sample. The strains were identified as belonging to the same genus and species, Aeromonas hydrophila. The rare unsaturated fatty acids and rare unsaturated fatty alcohols were accumulated as a wax ester form by the strains. Compared to other strains, the A. hydrophila isolates effectively decreased fatty acid chain lengths and converted rapeseed oil, which is rich in 9-C18:1 fatty acid, into rare fatty acids, such as 7-C16:1 fatty acid and 5-C14:1 fatty acid. Furthermore, the A. hydrophila isolates converted the resulting fatty acids to rare unsaturated fatty alcohols, such as 7-C16:1 fatty alcohol and 5-C14:1 fatty alcohol. The isolates also converted safflower oil, which is rich in 9,12-C18:2 fatty acid, to 7,10-C16:2 fatty acid, 5,8-C14:2 fatty acid, 9,12-C18:2 fatty alcohol, 7,10-C16:2 fatty alcohol, and 5,8-C14:2 fatty alcohol. 7,10,13-C16:3 fatty acid, 9,12,15-C18:3 fatty alcohol, and 7,10,13-C16:3 fatty alcohol were also converted from linseed oil, which is rich in 9,12,15-C18:3 fatty acid, by the A. hydrophila isolates. These fatty acids and fatty alcohols are rarely found in natural oils. Since decreasing fatty acid carbon chain lengths from the carboxyl end and reducing unsaturated fatty acids to unsaturated fatty alcohols are both difficult reactions to accomplish by chemical means, we suggest that these A. hydrophila isolates may facilitate introduction of new bioprocess for producing rare unsaturated fatty acids and rare unsaturated fatty alcohols, especially fatty alcohols harboring more than two double bonds.     

越南安息香种子脂肪酸的在线甲基化-GC分析研究

建立了分析越南安息香种子油、果实和果壳的脂肪酸组成的在线甲基化-气相色谱法。将微克级的安息香样品与2μL衍生化试剂三甲基氢氧化硫（0.2 mol/L）加入裂解器,在350℃下瞬间反应,由气相色谱在线检测到8种脂肪酸甲酯成分,主要有棕榈酸（ C16∶0）、硬脂酸（ C18∶0）、油酸（ C18∶1）、亚油酸（ C18∶2）和亚麻酸（ C18∶3）,不饱和脂肪酸含量在84.5%以上,其中亚油酸含量最高,达47.29%。5次平行测定的相对标准偏差（ RSD）小于3.81%。并结合相似性分析法比较了4种不同产地的安息香种仁与6种食用油的脂肪酸组成,相似性结果表明不同产地的安息香种仁的脂肪酸组成相似,其脂肪酸组成与食用植物油相近,与玉米油的组成分布最为接近,相似系数在0.987~0.990,且越南安息香种子中人体必需的多不饱和脂肪酸含量（ C18∶2和C18∶3）与大豆油和葵花籽油相近,高于一般植物油,具有较高的营养价值。结果表明该法简便、快速、准确,适合越南安息香种子油脂的测定。     

Fatty acid and aldehyde composition of major phospholipids in salt gland of marine birds and spiny dogfish

The lipophilic components of choline phosphoglycerides and ethanolamine phosphoglycerides obtained from the salt gland of herring gull and eider duck and from the rectal gland of spiny dogfish were investigated by means of thin-layer chromatography, gas chromatography, and gas chromatography-mass spectrometry. All phospholipids analyzed were shown to contain small amounts of plasmalogens, and mainly C16, C18, and C18∶1 aldehyde was detected. The fatty acids were composed of saturated, unsaturated, straight chain, and branched chain types, ranging between 14–22 carbon atoms. The lipophilic composition of the rectal gland phospholipids showed a higher degree of unsaturation and the presence of more branched chain fatty acids than that of the birds, possibly related to body temperature.     

脂肪酸系列捕集剂在废纸中的浮选脱墨实验

简介了脂肪酸捕集剂的捕集机理 ,选择了一系列脂肪酸配以TX -10作实验脱墨剂进行了应用试验 ,结果不饱和脂肪酸捕集油墨性能优于饱和脂肪酸 ,C18的脂肪酸优于C12 、C16的脂肪酸     

Sterol and phospholipid acyl chain alterations inSaccharomyces cerevisiae secretion mutants as a function of temperature stress

Analyses of free sterol, steryl ester and fatty acid components from yeast secretion mutants indicated that free and esterified sterol remained relatively constant over a growth range of 24 C to 34 C. The saturated fatty acid components (16∶0 and 18∶0) increased while the unsaturated fatty acids (16∶1 and 18∶1) decreased as the growth temperature increased. In secretory mutants, fatty acid composition changes are more pronounced than in the wild-type strain. A shift toward increased saturated and decreased unsaturated fatty acid was observed when cells were subjected to a 2-hr temperature upshift to 37 C. Steady-state fluorescence anisotropy data indicated that modifications to the lipid component of yeast plasma membrane produced lipid thermotropic transitions that were 3 C to 6 C higher in yeast cells subjected to thermal stress.     

General properties and the fatty acid composition of the oil from the mophane caterpillar, Imbrasia belina

A preliminary investigation of the bulk properties of the oil from the edible mophane caterpillar (phane), Imbrasia belina, showed a significant difference in the iodine values of the oils from mature and young phane. Detailed analysis of the fatty acid composition of the two oil samples was thus carried out by capillary gas chromatography (GC) and complemented with ¹H and ¹³C nuclear magnetic resonance (NMR) studies to investigate the degree of unstauration in the two oil samples. While these studies showed that the oil samples from the mature and young mophane caterpillar were much the same in fatty acid composition, the data revealed a significant divergence from a literature report on phane oil. This earlier report puts the ratio of total saturated to total unsaturated fatty acids at approximately 1:1 (48.2:48.8, in percentages) and estimates the fatty acid composition for the major fatty acids as 16:0 (31.9%), 18:0 (15.2%), 18:1 (20.4%), 18:2 (9.9%), and 18:3 (19%). The data collected from the present work, however, showed the fatty acid composition for total saturated and total unsaturated fatty acids to be 40.5 and 57.0%, respectively. This work estimated the fatty acid composition for the major fatty acids as 16:0 (27.2%), 18:0 (12.3%), 18:1 (16.1%), 18.2 (10.7%), and 18:3 (29.0%). Thus, linolenic acid was the most abundant fatty acid in the phane oil. The GC results of the present analysis were largely corroborated by studies of the composition of fatty acid classes in the phane oil estimated from integrals of ¹H and ¹³C NMR signals. Oils from other edible Lepidoptera larvae are also known to be much richer in unsaturated than saturated fatty acids.     

Solvent-Assisted Crystallization of Fatty Acid Alkyl Esters from Animal Fat

An easy and efficient method for the separation of saturated and unsaturated fatty acid mono alkyl esters, prepared from animal fat, was developed. The most efficient separation was achieved by the use of solvents such as methanol and acetone at low temperatures. The dilution of the alkyl esters with 10 times the amount of solvent (10:1 v/w) and storage of the mixture for 4 h at ?22 °C could be defined as optimum conditions. After filtration of the saturated fraction at the corresponding temperature very pure fractions were obtained. For fatty acid methyl esters deriving from tallow, with an initial content of saturated fatty acids of almost 50 %, a saturated ester fraction with only 5 % unsaturated fatty acids and an unsaturated ester fraction with about 9 % of saturated fatty acids could be obtained. The solvent easily could be recovered by distillation. In addition fatty acid ethyl, 1‐propyl, 2‐propyl, 1‐butyl, tert‐butyl and 3‐methyl‐1‐butyl esters were prepared and separated into saturated and unsaturated fractions. All fractions were analyzed according to the fatty acid compositions and showed similar or slightly worse results compared to the methyl esters. The cold filter plugging points of the unsaturated fractions were measured, showing the lowest value for the unsaturated methyl ester fraction at ?26 °C. The fractionation with the use of solvents is an easy tool in order to obtain fatty acid alkyl esters with excellent cold temperature behavior out of animal fat.     

Microbial production of rare unsaturated fatty acids and alcohols

Aeromonas hydrophila N‐6, isolated from a soil sample, converted vegetable oils to several rare unsaturated fatty acids and alcohols accumulated inside the cells as a wax ester form. A. hydrophila N‐6 effectively decreased fatty acid chain lengths, and converted rapeseed, safflower and linseed oils into 7‐16:1 and 5‐14:1 fatty acids, 7,10‐16:2 and 5,8‐14:2 fatty acids, and 7,10,13‐16:3 fatty acids, respectively. Furthermore, A. hydrophila N‐6 reduced the resulting fatty acids to rare unsaturated fatty alcohols, such as 7‐16:1, 5‐14:1, 9,12‐18:2, 7,10‐16:2, 9,12,15‐18:3 and 7,10,13‐16:3. Such unsaturated fatty acids and alcohols are rarely found in natural oils. Because decreasing fatty acid carbon chain lengths from the carboxyl end and reducing unsaturated fatty acids to unsaturated fatty alcohols in industrially applicable scale are both difficult reactions to accomplish by chemical means, we suggest that A. hydrophila N‐6 may facilitate the introduction of new bioprocesses for producing rare unsaturated fatty acids and alcohols, especially fatty alcohols with more than two double bonds.     

Fatty acid profile in baby food products

The fatty acid composition in the lipid phase of 64 commercially available baby food products, of two different batches each, was analyzed. They comprised vegetable products for babies of five, eight, and twelve months and fruit and cereal products of three different brands. The comparison of the composition of the saturated (C18:0, C16:0, C14:0, C12:0, C10:0), the unsaturated monoenoic (C18:1n9 and C16:1n7) and the polyenoic (C18:2n6 and C18:3n3) fatty acids was determined by gas chromatography. All analyzed baby food products provided well‐balanced amounts of saturated fatty acids on the one hand (saturated fatty acids (SFA) 31—37% of total fatty acids) and unsaturated fatty acids on the other hand (monounsaturated fatty acids (MUFA) 23—26% and polyunsaturated fatty acids (PUFA) 38—46% of total fatty acids, respectively). The P/S‐ratio in vegetable products of five months reached a value of 1.5, in all other analyzed products it was around 1. The n‐6:n‐3‐ratio was 10:1 in fruit and cereal products, followed by 11.6:1 in vegetable products of eight and twelve months and 13.5:1 in the group of vegetable products of five months. Since there is a lack of arachidonic acid and docosahexaenoic acid in baby food products, it might be of advantage to consider whether such products should be supplemented by these long‐chain polyunsaturated fatty acids.     

Effect of Some Preservatives on the Poultry Lipids

Some treatments were conducted for prolonging the self life of broiler meat such as storage at two different temperatures (3 °C and -18 °C) with and without adding chemical preservatives (NaCl, polyphosphate and a mixture of them). Fatty acid composition of blended skin tissue and subcutaneous carcasses lipids were qualitatively and quantitatively determined by gasliquid chromatography. The fatty acid analysis indicated that 16:0 and 18:1 were the most predominant saturated and unsaturated acids of fresh skin tissue and subcutaneous carcasses lipids. Dipping carcasses in hot water alone and with NaCl, polyphosphate or a mixture of them exhibited very little effect on the fatty acid pattern. Storage at 3 °C led to conversion of some long-chained and unsaturated fatty acids to mediumchained and saturated ones. Dipping carcasses in tap or hot water with or without preservatives caused quantitative changes in 16 :0,18 :0,18 :1 and 18 :2 acids. In general, the most efficient treatment towards keeping carcasses quality is storage at -18 °C without adding any chemical preservatives.     

Changes in the Fatty Acid Content of Used Frying Fat Compared with Fresh Fat

In 21 samples of used frying fat and the corresponding samples of fresh fat the fatty acid content was determined by capillary GLC on a CP Sil 88 column. The content of both saturated and unsaturated fatty acids as well as the content of total fatty acids are decreased by frying. Both the decrease in linoleic acid and the decrease in total fatty acids correlate well with % polar compounds as fat quality evaluation criteria. No isomers of cis,cis-linoleic acid are formed during the frying process. The content of C18: 1 is increased during the frying process from about 0 to 8g/100g in average to 2.3g/100g, which means that also the frying process must be considered as a source to the human intake of trans fatty acids.     

Effect of growth conditions on the fatty acid composition ofListeria monocytogenes and comparison with the fatty acids ofErysipelothrix andCorynebacterium

Six strains ofListeria monocytogenes belonging to four different serotypes all had similar fatty acid profiles when grown at 37 C, with C₁₅ and C₁₇ branched chain acids as major components. The proportion of 17∶0 br decreased markedly as the growth temperature was lowered from 37 C to 4 C, and a reduction of 18∶1 with increasing age of cultures was observed in cells harvested at different stages of the growth curve. The fatty acid composition was also affected by the nature of the culture medium. Two other genera of the family Corynebacteriaceae were analyzed for fatty acid composition. Strains ofErysipelothrix rhusiopathiae isolated from human, turkey, dog and pig had rather similar patterns, consisting mainly of straight chain, even-numbered fatty acids from C₁₀ to C₁₈. The three species ofCorynebacterum analyzed each had quite different fatty acid patterns.C. poinsettiae bore some resemblance toL. monocytogenes butC. pseudodiphtheriticum had much higher proportions of 16∶0 and 18∶1 andC. equi contained a rather complex mixture of fatty acids. Part of this work was carried out in the Collip Medical Research Laboratory.     

Fatty acid composition of French infant formulas with emphasis on the content and detailed profile oftrans fatty acids

The aim of the present study was to identify and quantitatetrans isomers of C18 fatty acids in some French infant formulas. Twenty powdered infant formulas were purchased in pharmacies and supermarkets in order to assess theirtrans mono- and poly-unsaturated fatty acids content. The fatty acid profiles were examined using methyl and isopropyl ester derivatives. The combination of gas-liquid chromatography, high-performance liquid chromatography, and silver nitrate thin-layer chromatography was needed to describe the detailed fatty acid compositions of the samples, includingtrans isomers of unsaturated C18 fatty acids. All the samples containedtrans isomers of C18∶1 acid (mean level 1.97±0.28% of total fatty acids), with vaccenic acid being generally the major isomer (15 out of 20 samples), thus indicating the origin from bovine milk. All the formulas also contained various isomers of linoleic and α-linolenic acids, but at lower levels.Trans PUFA isomers are the same as those present in deodorized oils. In conclusion, all the infant formulas analyzed in this study contained sometrans fatty acids, including isomers of essential fatty acids. This should be taken into account in the dietary intake of the newborn.     

Die unterschiedliche Bedeutung der Fettsäuren in ihrer fungistatischen Wirkung

Significance of Fatty Acids in Their Fungistatic Action The fungistatic action of saturated and unsaturated fatty acids, halogenated fatty acids and esters as well as sulfurcontaining derivatives is reviewed. Fungistatic agents, known since a long time, are propionic acid, caprylic acid and its salts as well as undecylenic acid and its salts. The recently known fatty acid derivatives having fungistatic action are morpholine and piperidine compounds of long chain fatty acids and the new class of aminimides of fatty acids with 14–16 C atoms.     

Cyclic fatty acids: Separation from straight-chain fatty acids by urea adducting

A mixture containing 37% cyclic and 63% straight-chain fatty acids, made by high-temperature treatment of linseed oil fatty acids with alkali, was separated by the urea adduct method to give unsaturated cyclic fatty acids (nonadduct) in 95% purity and 90–95% yeild. Previous reports from this Laboratory describe a process for separating cyclic fatty acids from stearic acid by hydrogenation followed by crystallization at −40C. The urea adduct method avoids hydrogenation and low-temperature crystallization, and furthermore, unsaturated cyclic and unsaturated straight-chain products can be recovered as individual fractions. Then, by readducting the unsaturated straight-chain fatty acid fraction, the small amounts of palmitic and stearic acids are removed leaving an unsaturated fraction containing oleic, nonconjugated and conjugated linoleic and some unsaturated cyclic fatty acids. Presented at AOCS Meeting, Los Angeles, April 1966. No. Utiliz. Res. Dev. Div., ARS, USDA.     

The separation of solid fatty acids from liquid fatty acids by the formation of acid soaps. I. Tallow soaps

The formation of acid soaps has been used successfully for the separation of a mixture of fatty acids into high and low iodine value fractions. The acid soaps of saturated acid can be made to crystallize from water leaving their unsaturated counter parts in solution. Acid soaps of saturated fatty acids are well characterized compounds with the formula R-COOM.R-COOH, where R is a straight alkyl chain, and M is sodium, potassium or ammonium. Optimum crystallization conditions involve a soap concentration of 2–5%, pH adjustment to between 7.0 and 8.0, an initial crystallization temperature not below 25C, and a crystallization period of at least 4 hr during which time cooling to a final temperature of 5–10C must be gradual, and agitation gentle.     

Fatty acid composition of seed oils of some members of the meliaceae and combretaceae families

Seed oils of some members of the Meliceae (six) and Combretaceae (three) were analyzed for their fatty acid composition. In oils of members of both families palmitic acid was the most abundant saturated acid. Trace amounts of short chain (C12–C14) and long chain (C20–C22) saturated acids were detected in some members of the two families. Oleic acid was the most abundant unsaturated acids in the oils of four members of the Meliaceae. However, in the oils ofCedrella odorata andLovoa trichilloides, dienoic acid (C18:2) was the major unsaturated acid. Strikingly high levels of trienoic (C18:3) and monoenoic (C16:1) acids were detected in the seed oils ofC. odorata andEnthandrophragma angolense, respectively. Oleic acid also was the most abundant unsaturated acid in the Combretaceae. The nutritional value and industrial potentials of these oils are given.     

Specific distribution of fatty acids in the triglycerides of rainbow trout adipose tissue. Influence of temperature

In the trout, the unsaturated fatty acids are preferentially located in the β-position and the saturated fatty acids in the α-position of triglycerides. This fatty acid distribution is retained even with diets containing lard. The fish are, therefore, able to modify completely the fatty acid distribution of dietary triglycerides. There is no retention of the β-monoglyceride structure during the biosynthetic processes. However, the modification of the dietary fatty acid distribution by the trout seems to be more difficult at 18 C than at 10C. Presented in part at the 13th World Congress of the International Society for Fat Research, Marseille, France, 1976.     

Quantitative effects of dietary polyunsaturated fats on the composition of fatty acids in rat tissues

A method combining data on fatty acid composition into subsets is used to illustrate general relative competitive selectivities in the metabolic and transport events that maintain fatty acid compositions in tissue lipids and to minimize differences among tissues or species in the amount of individual fatty acids. Fatty acid compositions of triglycerides and phospholipids in several tissues of the rat were maintained with simple relationships between the exogenous n−3 and n−6 dietary polyunsaturated fatty acids and the endogenous n−7 and n−9 types of fatty acid. The general pattern of fatty acids in triglycerides was similar for liver, plasma and adipose tissue, averaging about 30% as saturated acids, 67% as 16- and 18-carbon unsaturated acids and only about 2% as 20- and 22-carbon highly unsaturated acids. The tissues maintained a linear relationship between the amount of 18-carbon polyunsaturated fatty acids in the diet and in the tissue triglycerides, with the proportionality constant for 18∶3n−3 being 60% of that for 18∶2n−6. The total phospholipids of liver, plasma and red blood cells maintained about 45% of the fatty acids in the form of saturated fatty acids and 20–30% as 20- and 22-carbon highly unsaturated fatty acids irrespective of very different proportions of n−3, n−6 and n−9 types of fatty acids. In all three tissues, the 20-carbon highly unsaturated fatty acids of the n−3, n−6 and n−9 type were maintained in a competitive hyperbolic relationship with apparent EC₅₀ values for dietary 18∶2n−6 and 18∶3n−3 near 0.1% of dietary calories. The consistent quantitative relationships described in this study illustrate an underlying principle of competition among fatty acids for a limited number of esterification sites. This approach may be useful in predicting the influence of diet upon tissue levels of the substrates and antagonists of eicosanoid biosynthesis.