EFFECT OF POSTMORTEM AGING ON CHICKEN MUSCLE LIPIDS

Neutral lipids of fresh chicken breast muscles are shown to be triglycerides, sterols and sterol esters with only traces of mono- and diglycerides and free fatty acids. Phospholipids include measurable quantities of phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl inositol, phosphatidyl serine, sphingomyelin, diphosphatidyl glycerol, lysophosphatidyl choline and lysophosphatidyl ethanolamine. Fatty acid analyses of several of the lipid fractions are also included. Decreases in phosphatidyl choline and phosphatidyl ethanolamine coupled with increases in lysophosphatidyl choline, lysophosphatidyl ethanolamine and free fatty acids after 48 hr postmortem in the cold indicate phospholipase A activity concurrent with other postmortem changes. The significance of the results is discussed.     

Lipids of berseem (Trifolium alexandrinum) seed

Berseem seed oil was fractionated into non-polar and polar components. Tentative identification was made of hydrocarbons, sterol esters, triglycerides, free fatty acids and partial glycerides in the non-polar fraction and of lysophosphatidyl choline, phosphatidyl inositol, lysophosphatidyl ethanolamine, phosphatidyl choline, phosphatidyl glycerol, phosphatidyl ethanolamine, digalactosyl diglycerides, sterol glycosides, phosphatidic acid, monogalactosyl diglycerides, cerebrosides and esterified sterol glycosides in the polar fraction. The fatty acid constituents of the major polar and of all the non-polar lipid components are also reported.     

Lipids in cereals. 1. Pennisetum typhoideum

Two improved strains of Pennisetum typhoideum (‘bajra’) were found to have a free lipid content of about 5.0% and bound lipid content of about 0.5%. In the non-polar fraction, sterol esters and hydrocarbons, triglycerides, free fatty acids, free sterols and partial glycerides were present with triglycerides as the principal constituents. Polar lipids were separated by two-dimensional thin-layer chromatography and lecithin was found to be the major component. Sterol-containing glycolipids (sterol glycosides and esterified sterol glycosides) were present in appreciable amounts. Phosphatidyl ethanolamine, phosphatidyl glycerol, phosphatidyl inositol, lysophosphatidyl ethanolamine, lysolecithin, phosphatidic acid, poly-glycerophosphatide, mono- and di-galactosyl glycerides and cerebrosides have also been tentatively identified.     

Fungal lipids. II. Effects of varying concentration of nitrogen in the medium and incubation period on the chemical composition of lipids of Pythium irregulare Buisman

Effects of varying the concentration of nitrogen in the medium and the incubation period on the chemical composition of lipids of Pythium irregulare Buisman were studied. In general, with low C/N ratios, the growth of mycelium and the lipid synthesis were found to increase up to the eleventh day of incubation after an initial lag period of five days. Thereafter only slight changes were observed. The fatty acid composition with low C/N ratios showed a considerable variation throughout the growth period. With high C/N ratios, the lipid content continued to increase during the whole period of growth. During this phase of growth, a rapid synthesis of triglycerides along with a marginal increase in the polar fraction was observed. In all the non-polar lipid classes, oleic and palmitic were the major fatty acid components. Free fatty acid fractions comprised mainly of palmitic, oleic and arachidic acids. In all polar lipid fractions, except phosphatidyl choline and phosphatidic acids, oleic and palmitic were the principal acids. By argentation thin-layer chromatography, eight mixed triglyceride classes were observed.     

Changes in phospholipids of buffalo meat during processing and storage

Effect of broiling and pressure cooking as well as alterations during refrigerated (4°C) and frozen (-10°C) storage on the phospholipids of adult male buffalo muscles viz. Triceps brachii (TB), Longissimus dorsi (LD) and Biceps femoris (BF), i.e. from three different locations were studied. Muscles differed significatly in their total lipid and phospholipid content. Cooking methods significantly altered the total phospholipid content and its fractions. Storage period did not show any significant effect on total phospholipids during refrigerated and frozen storage, whereas certain phospholipid classes viz. lysophosphatidyl choline and lysophosphatidyl ethanolamine + sphingomyelin increased significantly and major phospholipid classes viz. phosphatidyl choline and phosphatidyl ethanolamine decreased significantly. The changes in phospholipid classes were similar both in refrigerated and frozen samples but relatively more pronounced in the former. Palmitic, stearic, oleic and linoleic acids were the four predominant fatty acids in the phospholipids of buffalo meat. The effects associated with the location of muscles were evident. Differences in fatty acid composition of individual muscles in response to heat processing were observed. Heat processing significantly increased the total saturates in TB and LD muscles while it decreased in BF. The total monounsaturated and total polyunsaturated fatty acids of phospholipids decreased during refrigerated and frozen storage indicated by a significant decreass in oleic, linoleic and arachidonic acids.     

Composition of wheat-flour lipids

Lipids were extracted from a single sample of wheat flour using three solvent systems: ethanol–diethyl ether–water (2:2:1 by vol.); chloroform–methanol (2:1 by vol.); and water-saturated n-butanol. Analysis of the extracts and of residual lipid in the extracted flour showed that water-saturated n-butanol was the most efficient solvent. Wheat-flour lipids were extracted with water-saturated n-butanol and separated by chromatographic procedures into individual components. The lipid classes which were isolated and studied were steryl ester, free sterol, 6-O-acyl steryl glucoside, steryl glucoside, triglyceride, diglyceride, monoglyceride, free fatty acid, monogalactosyl diglyceride, 6-O-acyl monogalactosyl diglyceride, digalactosyl diglyceride, digalactosyl monoglyceride, monoglycosyl ceramide, diglycosyl ceramide, N-acyl phosphatidyl ethanolamine, N-acyl lysophosphatidyl ethanolamine, phosphatidyl ethanolamine, lysophosphatidyl ethanolamine, phosphatidyl choline, lysophosphatidyl choline, phosphatidyl serine and phosphatidyl inositol. Monogalactosyl monoglyceride was also tentatively identified. The quantitative distributions of the lipid classes were determined. Monoglycosyl ceramide contained small amounts of normal fatty acids (12:0–24:0) and large amounts of 2-hydroxy fatty acids (principally 16:0 and 20:0), with similar amounts of dihydroxy long-chain bases (18:0 and 18:1) and trihydroxy long-chain bases (18:0, 18:1, 19:0, 19:1, 20:0, 22:0). The principal sterols were identified as β-sitosterol, campesterol, and C₂₈ and C₂₉ saturated sterols. The fatty acids in the sterol lipids were principally 16:0 (50–60%) and 18:2 (28–30%) with small amounts of 16:1, 18:0, 18:1 and 18:3. The fatty acids in all the glycerides were principally 18:2 (51–84%) with lesser amounts of 16:0, 18:0, 18:1 and 18:3.     

Lipid Content and Fatty Acid Composition in Bamboo Shoots

Lipids from bamboo shoots (Phyllostachys pubescens), peeled and divided from top to base, were extracted and fractionated into three classes, and each class separated into constituent components by thin-layer chromatography (TLC). Fatty acid composition and amount of separated lipids were determined. Total lipids (TL) ranged from 800 (top) to 380 mg (base) per 100g fresh weight and the ratio of nonpolar lipids (NPL):glycolipids (GL):phospholipids (PL) was about 17:27:56. The main fatty acids of the three lipid classes were palmitic, linoleic and linolenic acids, but composition was remarkably different among these fractions. The fatty acid composition of triglycerides (TG) was similar to the original NPL. Palmitic acid was almost all located in 1-, 3-position, linoleic acid mainly located in 2-position of TG, while linolenic acid was distributed in each position. Digalactosyl diglyceride (DGDG) and monogalactosyl diglyceride (MGDG) were the main components of GL; the average of the former had about 37% linoleic and 29% linolenic acids, while the latter had about 25% linoleic and 62% linolenic acids. Bamboo shoots contained 9 PL fractions, the major being phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE). PC contained about 48% linoleic, 31% palmitic and 11% linolenic acids, and PE also had the similar tendency as PC.     

Identification and Quantitative Analysis of Phospholipids in Cocoa Beans

SUMMARY: The lipids extracted from several common cocoa bean varieties were separated into neutral lipid, glycolipid, and phospholipid fractions. The composition of the total lipid extract was 98% neutral lipid and 1 to 2% oolar lioid of which aporoximatelv 70% was glycolipid and 30% was phospholipids. Two-dimensional thin-layer chromatography was used to separate all of the known major phospholipids. The relative distribution of the phospholipids was determined by quantitative phosphorus analyses of individual spots scraped from two-dimensional thin-layer plates. The major components were lysophosphatidyl choline, phosphatidyl choline, phosphatidyl ethanolamine, and phosphatidyl inositol. Phosphatidyl choline was found to contribute 36 to 40% of the phospholipids of cocoa beans. The phospholipid composition of Accra, Arriba, and Bahia beans was shown to be quite similar although minor variations were observed.     

LIPIDS OF CURED CENTENNIAL SWEET POTATOES

SUMMARY –Lipids isolated from cured Centennial sweet potatoes were identified and quantitated by a combination of column and thin layer chromatography. These lipids were shown to consist of 42.1% neutral lipids, 30.8% glycolipids and 27.1% phospholipids. Triglycerides and steryl esters were the major lipids of the neutral fraction. Among the phospholipids, phosphatidyl ethanolamine, phosphatidyl choline and phosphatidyl inositol were the most abundant. Galactolipids and the steryl glucosides were also present. The predominant fatty acids were stearic, palmitic, oleic, linoleic and linolenic.     

Mesocarp,seed and pollen lipids of Raphia palms

The lipid classes, fatty acids and sterols of the mesocarp, seed and pollen lipids of five species of Raphia palms endemic to Nigeria were analysed. Apart from quantitative differences in the fatty acid compositions, chromatographic analyses demonstrated very little change in the patterns of the characteristic lipids associated with either the mesocarps, seed endosperms or pollens. Mesocarp lipids contained mainly triglycerides, while palmitic, oleic and linoleic acids were the major acids. Contrary to published data for seed lipids, Raphia seed endosperms contained a relatively small amount of triglycerides and a high proportion of polar lipids. Fatty acids associated with this tissue were not only highly unsaturated, but were significantly different from typical fatty acids of seed lipids. Raphia pollens, on the other hand, showed a complex array of lipid types. Triglycerides, sterols and sterol esters constituted the main neutral lipids while phosphatidyl choline, phosphatidyl inositol, phosphatidyl ethanolamine and galactosyl diglycerides represented the polar fraction. Apart from minor trends, palmitic, oleic and linoleic acids constituted the major fatty acids in all species. The biological importance of the steroidal sapogenins found in all organs is discussed.     

Characterization of Shrimp Lipids

Edible shrimp (Penaeus aztecus) tissue contains approximately 1.2% extractable lipids, the majority of which are phospholipids. Data from the gravimetric quantitation of lipid classes isolated by column chromatography indicated that phosphatidyl choline was the predominant phospholipid and cholesterol the predominant neutral lipid in edible shrimp tissue. Fatty acid distribution data indicated that sphingomyelins contained the greatest percent by weight of unsaturated fatty acids while cholesterol esters contained the greatest proportion of saturated fatty acids. Enzymatic hydrolysis followed by gas liquid chromatography of phosphatidyl choline, phosphatidyl ethanolamine, and phosphatidyl serine indicated that fatty acids located at the β position were more highly unsaturated than those at the α position.     

Changes in the composition of the rumen and abomasum lipids of sheep from birth to maturity

The composition of the lipids of the rumen and abomasum tissues of foetal (at term), 1 month, 2 month and 1-2-year old sheep grazed on pasture has been determined. The lipid content of the rumen tissues increased from 2.0% at birth to 3.4% in 1-2-year old sheep While that of the abomasum tissues increased from 2.6 to 5.7%. The main change in the neutral lipid fraction was a decrease in the hydrocarbon content from 0.13 % in the rumen tissues and 0.08 % in the abomasum tissues at birth to 0.003% and 0.006% respectively in the 1-2-year old sheep. The main components of the phospholipid fraction of the rumen and abomasum tissues were 34.9- 46.8% phosphatidyl choline; 14.623.5 % phosphatidyl ethanolamine; 14.3-21.1 % sphingomyelin; with smaller amounts of lysophosphatidyl choline (4 13-12.6 %), acidic phospholipids (cardiolipin) (4.1-8 -5 %) and phosphatidyl inositol/phosphaticlyl serine (3.0-5.5 %). No marked changes in phos- pholipid composition with age were noted. The amounts of phosphatidyl choline and phosphatidyl ethanolamine tended to be higher in the abomasum than in the rumen whereas the sphingomyelin content of the rumen tissue phospholipids was generally greater than that of the abomasurn tissue phospholipids. From the fatty acid composition of the triglycerides of the rumen and abomasum tissues it appeared that the foetal triglycerides were largely, though not entirely, of endogenous origin. In contrast the phospholipids of the foetal rumen and abomasum tissues contained di- and poly-unsaturated as well as branched-chain fatty acids in proportions similar to those found in older animals having access to pasture. From these results it is suggested that the phospholipids of the foetus are derived to a considerable extent from the maternal phospholipids.     

Supercritical fluid extraction and characterization of lipids from algae scenedesmus obliquus

Supercritical carbon dioxide (SC‐CO₂) extractions (with and without ethanol as an entrainer) were carried out to remove lipids and pigments from protein concentrate of green algae (Scenedesmus obliquus) cultivated under controlled conditions. The content and fatty acid composition of algal lipids using column, thin‐layer (TLC) and gas‐liquid chromatography (GLC) were determined. Absorption spectra of extracted fractions showed the predominance of chlorophyll A (λ_max at 410nm). Single step supercritical carbon dioxide (SC‐CO₂) extraction resulted mostly in removal of neutral lipids and a part of glycolipids, but phospholipids were not extracted. Addition of ethanol to SC‐CO₂ increased the amount of glycolipids and phospholipids in the extract. TLC pattern of algal lipids showed that the main part of neutral lipids consisted of diglycerides, triglycerides, hydrocarbons, free sterols, and sterol esters. The glycolipids were mostly monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. In phospholipids, phosphatidyl choline, phosphatidyl glycerol, and phosphatidyl ethanolamine were the main compounds. Fatty acid composition patterns indicated the main fatty acids to be 16:0, 16:1, 16:2, 16:3, 16:4, 18:1, 18:2 and 18:3(a). Relatively high recovery of polyunsaturated fatty acids and essential fatty acids in supercritical fluid extracted algal lipids and protein isolates were observed.     

Phospholipids of marine origin. I. The hake (Merlucius capensis, Castelnau)

The composition of hake flesh and hake liver phospholipids was determined by an hydrolytic procedure and by chromatography on silicic acid. The hydrolytic procedure involved determination of lecithin-choline, sphingornyelin-choline, lyso lecithin-choline, ethanolamine, serine, myo-inositol and the average equivalent weight of the liberated fatty acids. The composition of the flesh and liver phospholipids was very similar, the latter contained more sphingomyelins and cardiolipins at the expense of phosphatidyl choline. Phospholipid fatty acids had a markedly higher equivalent weight and unsaturation than the corresponding non-phosphorylated lipid fatty acids. The cephalin fractions contained more long chain polyunsaturated fatty acids, more stearic acid and less palmitic acid than the phosphatidyl choline fractions. Sphingomyelins were particularly rich in lignoceric and nervonic acid.     

Role of seed phosphatides as antioxidants for ghee (butter fat)

Antioxidant potentiality of seed phospholipids for stored ghee was found to be in the order of sunflower (Helianthus annuus L.), groundnut (Arachis hypogea), soybean (Glycine max) and cotton seed (Gossypium sp.), possibly corresponding to their phosphatidyl ethanolamine content. Out of phosphatidyl choline, phosphatidyl ethanolamine and phosphatidic acid, phosphatidyl ethanolamine was found to be the most effective antioxidant. Antioxidant property of phosphatidyl ethanolamine did not vary with the seed source, indicating that the fatty acid portion of the molecule played no role in protecting ghee against oxidation. In stored ghee addition of phosphatidyl ethanolamine and phosphatidyl choline reduced lipolysis, probably by interacting with the lipase system. During storage, phosphatidyl ethanolamine afforded better protection against the oxidation of unsaturated fatty acids.     

The fatty acid composition of the main phospholipid fractions of the rumen and abomasum tissues of foetal and adult sheep

The fatty acid composition has been determined on phosphatidyl choline, phos-phatidyl ethanolamine and sphingomyelin fractions earlier isolated from the rumen and abomasum tissues of foetal and of adult Romney sheep. The major proportion of polyunsaturated fatty acids was found in the phosphatidyl ethanolamine (17 to 43%) fraction and this was reduced in the phosphatidyl choline (7 to 25%) and sphingomyelin (1 to 4%) fractions. These features are in keeping with the results for mammalian tissues generally. The phosphatidyl ethanolamine fractions were further characterised by the low content of palmitic acid (<8%) compared with 25 to 30 % in the phosphatidyl choline fractions and 29 to 52% in the sphingomyelin fractions and by the occurrence of cyclopropane fatty acids. Consistent with the findings of other workers on mammalian tissues, the sphingomyelin fractions contained a relatively high content (16 to 27%) of higher w-saturated fatty acids including 22:0,23:0,24:0 and 25:0 and of tetracos-14-enoic (24:1 ω9) acid (5 to 16%). The total amounts of acids above C₂₀ tended to vary inversely with the levels of palmitic acid whereas the levels of stearic acid were relatively constant at 13 to 17%. Changes in fatty acid composition with age were generally not marked but the tissues of the foetus were distinguished from those of the foetus were distinguished from those of the adult by their substantial amount of eicosa-5,8,11-trienoic (20:3 ω9) acid together with relatively low contents of linoleic (18:2 ω6) and linolenic (18:3 ω3) acids and to a leser extent by reduced level of acids of the ω3 series. This was particularly reflected by the ratios of ω6/ω3 C₂₀ + C₂₂ acids in the phosphatidyl ethanolamine fractions, the valucs for the foetal rumen and abomasum tissues being 1.03 and 1.07, respectively, compared with corresponding values of 0.78 and 0.72 found in adult sheep. The results are consistent with a requirement for C₂₀ and C₂₂ polyunsaturated acids of the ω3 and ω6 series and some penetration of maternal fatty acids through the placenta. The resemblance between the fatty acid make-up and composition of foetal and maternal phospholipids suggests the possibiligy of transference of intact or lyso-phospholipids from the mother to the foetus through the placenta. However, such a possibility is counter-indicated by consideration of previous work using labelled intermediates and by the mechanism of conversion of linoleic and linolenic acids requiring their CoA derivatives in the formation of the corresponding polyunsaturated C₂₀ + C₂₂ acids. Nevertheless, the sharp cut-off of exogenous maternal fatty acids from the foetal triglycerides and their inclusion in the foetal phospholipids are not readily explainable.     

Phospholipids of marine origin. IV. The abalone (Haliotis midae)

Phospholipids of the abalone were separated into component fractions by chromatography on silicic acid. The phospholipids were remarkable for the presence (6%) of an unusual sphingolipid liberating 2-amino-ethylphosphonic acid on hydrolysis, and for the high proportion of plasmalogens (23%). The presence of phosphatidyl ethanolamine plus ethanolamine plasmalogen (32%), phosphatidyl serine (5%), phosphatidyl inositol (5%), phosphatidyl choline (41%) and sphingomyelin (1%) were also demonstrated. The fatty acid distribhion in the phospholipids, the non-phosphorylated lipids and the unusual sphingolipid was determined by gas chromatography. In general these results show a similarity between the phospholipid and the non-phosphorylated lipid fatty acids, the former being richer in long chain polyunsaturated fatty acids. Fatty acids of the unusual sphingolipid were outstanding for the high palmitic (53%) and stearic acid (15%) content.     

Supercritical fluid extraction and characterization of lipids from algae Scenedesmus obliquus

Supercritical carbon dioxide (SC-CO2) extractions (with and without ethanol as an entrainer) were carried out to remove lipids and pigments from protein concentrate of green algae (Scenedesmus obliquus) cultivated under controlled conditions. The content and fatty acid composition of algal lipids using column, thin-layer (TLC) and gas-liquid chromatography (GLC) were determined. Absorption spectra of extracted fractions showed the predominance of chlorophyll A (lambda max at 410 nm). Single step supercritical carbon dioxide (SC-CO2) extraction resulted mostly in removal of neutral lipids and a part of glycolipids, but phospholipids were not extracted. Addition of ethanol to SC-CO2 increased the amount of glycolipids and phospholipids in the extract. TLC pattern of algal lipids showed that the main part of neutral lipids consisted of diglycerides, triglycerides, hydrocarbons, free sterols, and sterol esters. The glycolipids were mostly monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. In phospholipids, phosphatidyl choline, phosphatidyl glycerol, and phosphatidyl ethanolamine were the main compounds. Fatty acid composition patterns indicated the main fatty acids to be 16:0, 16:1, 16:2, 16:3, 16:4, 18:1, 18:2, and 18:3(a). Relatively high recovery of polyunsaturated fatty acids and essential fatty acids in supercritical fluid extracted algal lipids and proteins isolates were observed.     

超高效液相色谱-静电场轨道阱高分辨质谱鉴定核桃仁的脂质构成

利用超高效液相色谱-静电场轨道阱高分辨质谱系统鉴定了核桃的脂质组.在正负离子模式下获得脂质的一级质谱和二级质谱信息后,共鉴定出4大类525种脂质分子,包括250种甘油酯、221种磷脂、18种糖脂、36种鞘脂类,含量分别占总脂质的87％、12.97％、0.02％和0.01％.甘油二酯(diacylglycerol,DG)...     

Relative Role of Individual Phospholipids on Thiobarbituric Acid Reactive Substances Formation in Chicken Meat, Skin and Swine Aorta

Fatty acid profiles and distribution of individual phospholipids (PL) in the total PL were determined in chicken meat and skin and swine aortas, and the contribution of each PL to malondialdehyde (MDA) formation was studied. Results indicate that phosphatidyl choline (PC) and phosphatidyl ethanolamine (PE) produced 70-77% of the total PL MDA while 16-25% of the MDA was formed by phosphatidyl inositol (PI) and phosphatidyl serine (PS). Much lower concentrations of MDA (3-6%) were formed by sphingomyelin (SP), cardiolipin (CL) and lysophosphatidyl choline (LyPC). In all analyzed tissues, both the MDA concentration and the percentage of polyenoic fatty acids, especially arachidonic acid, were highest in PI followed by PE, PS, PC, CL LyPC, and SP.