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.     

Permeate Flux During Ultrafiltration of Whey: Influence of Milk Coagulant Used for Cheese Manufacture

A pilot-scale plate and frame UF system was used to fractionate Cheddar cheese whey and study the effects of different commercial milk coagulants on permeate flux. Coagulants used in this study were calf rennet, Mucor pusillus protease, and Mucor miebei protease. Whey UF performance studies were conducted at a commercial Cheddar cheese plant and at Cornell under controlled conditions. Ultrafiltration was done in a continuous mode and initial concentration factor was set at 2× to simulate the first stage of a multistage whey UF system.Permeate flux decline was rapid in the first 30 min of UF for all wheys studied. More important, the type of milk coagulant used in cheese making had a profound effect on permeate flux during whey UF. No differences in the gross composition of the various wheys were correlated with differences in permeate flux. The highest permeate flux was measured for UF of whey produced during manufacture of Cheddar cheese using coagulant derived from Mucor pusillus. Lowest permeate flux was measured for UF of whey produced during manufacture of Cheddar cheese using calf rennet. Whey from cheese manufactured using Mucor miebei coagulant had flux performance intermediate to Mucor pusillus and calf rennet. The impact of milk coagulants on whey UF process efficiency should be considered by cheese makers.     

Fatty acid and aldehyde composition of individual phospholipid classes of rabbit skeletal muscles is related to the metabolic type of the fibre

The fatty acid composition of individual phospholipid classes as related to metabolic type of fibre in the rabbit was studied. The fatty acid composition of the individual phospholipid classes of five muscles were compared: two glycolytic ones (Longissimus lumborum and Psoas major), two oxidative ones (Soleus and Semimembranosus propriosus,) and an intermediate one (Gastrocnemius laterale). It was shown that except for phosphatidyl inositol (PI), the fatty acid compositions of the main phospholipid classes were strongly related to the metabolic type of the fibres; phosphatidyl ethanolamine (PE) of oxidative muscles contains less 18:2 n-6 and more 18:0 and long chain PUFA of the n-6 and n-3 series than that of glycolytic ones; phosphatidyl choline (PC) of oxidative muscles contains more 18:0 and less 16:0 and 18:2 n-6 than that of glycolytic ones; cardiolipin of the oxidative muscles contains less 18:2 n-6 than those of the glycolytic ones. These differences in fatty acid composition of PE, PC and cardiolipin explain a large part of the differences in fatty acid compositions of the total phospholipids of glycolytic and oxidative muscles.     

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 milk fat phospholipids during lactation

Changes in lipid composition were studied in milk obtained on postpartum d 3 (colostrum), 7, 42, and 180 from 12 Holstein cows. Triglycerides, 96 to 97% of total lipids, were relatively constant during lactation. Phospholipids and cholesterol declined with advancing lactation. Concentrations of the fatty acids synthesized within the mammary gland, C10:0 to C16:0, increased about 50% from 7 to 42 d of lactation. During this period, compensatory decreases were observed in C18:1. The phospholipids were separated into five major classes: sphingomyelin, phosphatidyl choline, serine, inositol, and ethanolamine for fatty acid analysis. The changes that occurred in milk total fatty acids were reflected in phosphatidyl phospholipid fatty acid composition: an increase in medium-chain fatty acids and a decrease in polyunsaturated fatty acids of 18, 20, and 22 carbon atom chain length as lactation progressed. These changes are consistent with the theory that milk phospholipids are synthesized de novo entirely in the mammary gland.     

Cheddar Cheese from Ultrafiltered Whole Milk Retentates in Industrial Cheese Making

Transporting whole milk retentates of ultrafiltration to a distant large industrial Cheddar cheese making site resulted in 16 lots of Cheddar cheese from vats containing 2,546 to 16,360 kg of cheese milk. Whole milk retentates concentrated by ultrafiltration to 4.5:1 were added to cheese milks to give mixtures concentrated 1.2:1 and 1.3:1 with approximately 20 and 30% more protein and fat, respectively, than in unsupplemented control whole milks or unsupplemented commercial reference milks.Gross composition of Cheddar cheese made from commercial reference, control, and retentate-supplemented milk generally showed no major differences. Yield increased in cheese made from retentate-supplemented milk. Yield efficiency per kilogram total solids rose in retentate cheese over controls but not among commercial reference, control, and retentate lots based on per kilogram fat or total protein. Milk components were higher in wheys from retentate cheeses, but loss of components per kilogram cheese obtained generally showed lower values in whey from retentate cheese.General quality of retentate Cheddar cheese was equal to that of reference unsupplemented commercial cheese and higher than unsupplemented control Cheddar cheeses. It appears technically feasible to ultrafilter milk at one site, such as the farm, collecting station, or specialized center, and transport it to an industrial site for Cheddar cheese making.     

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.     

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.     

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.     

虾头中磷脂提取与组学分析

研究虾头中磷脂的提取制备方法,并分别利用气相色谱法和多维度串联质谱法对样品磷脂的脂肪酸链结构进行脂质组学分析。利用乙醇浸提法制备得到虾头中的磷脂,并从乙醇体积分数、提取温度和提取时间3?个因素对提取方法进行优化,得到较优条件为乙醇体积分数90%、提取温度50?℃、提取时间30?min,磷脂的提取效果最佳,实际提取量可达到（11.58±0.03）mg/g,与优化前相比提高了83.8%。磷脂样品经甲酯化反应后用气相色谱法分析其脂肪酸链组成,并用高效液相色谱-质谱联用技术经负离子全扫描对磷脂分子实现分离鉴定和定量分析。结果显示,磷脂的脂肪酸链中主要含有棕榈酸链、亚油酸链、二十碳五烯酸和硬脂酸链等23?种脂肪酸链,其中单不饱和脂肪酸链占9.51%,多不饱和脂肪酸链占35.33%;磷脂样品中共检出磷脂酰胆碱、磷脂酰乙醇胺、磷脂酰肌醇和磷脂酰丝氨酸4?类共28?种磷脂分子,该提取方法所得各种类磷脂的脂肪酸链中存在许多不饱和度较高的脂肪酸链,如40∶8、36∶7、38∶7、O-40∶7、40∶7、34∶6、O-36∶6、36∶6、O-38∶6、38∶6、40∶6等。虾头中磷脂含量丰富,其脂肪酸链不饱和度较高,因此具有较高的开发利用价值。     

Seasonal changes in phospholipids of mussel (Mytilus edulis Linne)

The phospholipids of mussels (Mytilus edulis Linne) from the coast of Qingdao were extracted, fractionated and analysed over a 12 month period. The contents of total lipids, neutral lipids, polar lipids and phospholipids were measured. The composition of phospholipids was determined by high‐performance liquid chromatography, and their fatty acid composition was analysed by gas chromatography. The phospholipid content ranged from 3.6 to 6.4 g kg^?1 soft tissue. PE (phosphatidyl ethanolamine) and PC (phosphatidyl choline) were the major constituents. C16:0, C20:5 and C22:6 were the major fatty acids. C20:5 (5.25–23.10%) and C22:6 (6.05–20.42%) varied regularly with the seasonal factors. Their total amounts were high from January to June, which would be an optimal time for the utilisation of the phospholipids of mussels. © 2002 Society of Chemical Industry     

The composition of the fatty acids and aldehydes of the ethanolamine and choline phospholipids of various meats

The ethanolamine phospholipids of beef, lamb, pork and chicken examined in this study contained over 40% of ethanolamine plasmalogen, whereas fish contained only 13%. The level of choline plasmalogen in choline phospholipids was less than 1% in fish and ranged from 10 to 30% in the other four meats. Palmitaldehyde was the major fatty aldehyde in the choline plasmalogens of beef, lamb, pork and chicken (65–80% of total aldehydes), but was present at lower levels in the ethanolamine plasmalogens. The per cent fatty acid compositions of phosphatidylethanolamine and the corresponding ethanolamine plasmalogen were very similar, being typically low in palmitic acid but very high (56–74%) in polyunsaturated fatty acids. The fatty acids of the choline plasmalogens contained more polyunsaturated fatty acids than the corresponding phosphatidyl cholines, but at lower levels than in the fatty acids of the ethanolamine phospholipids.     

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.     

Lipolytic and oxidative changes in two Spanish pork loin products: dry-cured loin and pickled-cured loin

Lipolytic and oxidative changes were studied in two typical meat products from pork loin, dry-cured loin (DCL) and pickled-cured loin (PCL). Neither product registered changes in the percentages of the main lipid fractions: non polar lipids, phospholipids and cholesterol. However, in dry cured loin an important decrease was recorded in the main phospholipid classes, phosphatidyl choline and phosphatidyl ethanolamine. Muscle lipolytic enzymes were active in both products, and were accompanied by a significant increase in free fatty acids, from 0.580% (of total lipid) in fresh loin to 5.65 in DCL and 2.95% in PCL. With respect to oxidative changes, the peroxide value decreased in both products, and the TBA number only increased in PCL.     

Phospholipids of marine origin. V. The crab--a comparative study of a marine species (Cyclograpsus punctatus) and a fresh water species (Potamon)

A comparison has been made between phospholipids extracted from a marine crab and from a fresh water crab. Marine crab (body and viscera) contained a phospholipid fraction which liberated 2-aminoethylphos-phonic acid upon hydrolysis, while this substance was absent from the fresh water crab. Marine crab phospholipids had a higher content of phosphatidyl choline (57%), a higher content of phosphatidyl serine (5%) but a lower content of phosphatidyl ethanolamine (22%) than phospholipids from the fresh water crab (respective values: 52, 2 and 27%). Marine crab phospholipids and non-phosphorylated lipids were richer in C20 plus C22 fatty acids but poorer in C18: 2 acid, than were the corresponding lipids from the fresh water crab.     

Impact of ropy and capsular exopolysaccharide-producing strains of Lactococcus lactis subsp. cremoris on reduced-fat Cheddar cheese production and whey composition

Cheddar cheese mixed starter cultures containing exopolysaccharide (EPS)-producing strains of Lactococcus lactis subsp. cremoris (Lac. cremoris) were characterized and used for the production of reduced-fat Cheddar cheese (15% fat). The effects of ropy and capsular strains and their combination on cheese production and physical characteristics as well as composition of the resultant whey samples were investigated and compared with the impact of adding 0.2% (w/v) of lecithin, as a thickening agent, to cheese milk. Control cheese was made using EPS-non-producing Lac. cremoris. Cheeses made with capsular or ropy strains or their combination retained 3.6–4.8% more moisture and resulted in 0.29–1.19 kg/100 kg higher yield than control cheese. Lecithin also increased the moisture retention and cheese yield by 1.4% and 0.37%, respectively, over the control cheese. Lecithin addition also substantially increased viscosity, total solid content and concentrating time by ultra-filtration (UF) of the whey produced. Compared with lecithin addition, the application of EPS-producing strains increased the viscosity of the resultant whey slightly, while decreasing whey total solids, and prolonging the time required to concentrate whey samples by UF. The amount of EPS expelled in whey ranged from 31 to 53 mg L⁻¹. Retention of EPS-producing strains in cheese curd was remarkably higher than that of non-producing strains. These results indicate the capacity of EPS-producing Lac. cremoris for enhanced moisture retention in reduced-fat Cheddar cheese; these strains would be a promising alternative to commercial stabilizers.     

基于“鸟枪法”磷脂组学的稻谷品种鉴别分析研究

以江苏、黑龙江和辽宁3个产地的4个稻谷品种为试材，建立“鸟枪法”磷脂组学鉴别我国不同地区和品种的稻谷。利用“鸟枪法”质谱技术鉴定稻谷中磷脂种类，通过偏最小二乘判别分析(PLS-DA)进行品种间的差异分析。结果发现，稻谷中磷脂种类达67种，主要包括磷脂酰胆碱、磷脂酰乙醇胺、磷脂酰甘油、溶血磷脂酰胆碱、溶血磷脂酰乙醇胺和溶血磷脂酰甘油，不同品种稻谷中磷脂含量存在差异。结合PLS-DA的方法可以区分4个稻谷品种，确定不同品种磷脂差异的贡献组分，可实现不同稻谷品种间磷脂特征的差异分析。因此，“鸟枪法”质谱结合PLS-DA分析，可以快速鉴定稻谷品种。     

Isolation of bovine immunoglobulins and lactoferrin from whey proteins by gel filtration techniques

Whey is a suitable source of immunoglobulins and lactoferrin to enrich infant formulas. Gel filtration on Sephacryl S-300 and on Fractogel TSK HW-55 was used to isolate immunoglobulins from colostral whey, acid whey, and Cheddar cheese whey. The SDS-PAGE and immunoelectrophoresis techniques indicated that the purity of the fractions from fractionation on Sephacryl S-300 was better than that by fractionation on TSK HW-55 column. Biological activity of fractions from the Sephacryl S-300 column as assessed by immunochemical analysis was 99, 83.3, and 92% for colostral, acid, and sweet wheys. The well-proven antimicrobial agent, lactoferrin, was isolated from sweet whey by heparin-attached Sepharose. Lactoferrin selectively adsorbed to the column was subsequently eluted with 5 mM Veronal-HCl containing .5 M NaCl, pH 7.4. Purity of the isolated protein was confirmed by SDS-PAGE and immunoelectrophoresis.     

Physicochemical characterization of Mozzarella cheese wheys and stretchwaters in comparison with several other sweet wheys

To better understand the origins of the problems occurring during Mozzarella cheese whey concentration, lactose crystallization, and spray-drying steps, a physicochemical characterization was achieved. For this purpose, Mozzarella cheese wheys were sampled and their content in different compounds such as total nitrogen, noncasein nitrogen, nonprotein nitrogen, lactate, citrate, chloride, sulfate, phosphate anions, calcium, magnesium, potassium, sodium cations, and the sugars glucose and galactose were measured. In a second step, the results were compared with the corresponding content in Cheddar cheese wheys, Raclette cheese wheys, soft cheese wheys, and Swiss-type cheese wheys. At the end of this survey, it was shown that Mozzarella cheese wheys were more concentrated in lactate and in minerals—especially phosphate, calcium, and magnesium—than the other cheese wheys and that they contained galactose. These constituents are known to be hygroscopic. Complementary surveys are now necessary to compare the hygroscopicity of galactose and lactate and discover whether the amounts of these compounds found in Mozzarella cheese wheys are a factor in the problems encountered during the concentration, lactose crystallization, and spray-drying steps.     

Lipid content and fatty acid composition of green algae Scenedesmus obliquus grown in a constant cell density apparatus

The lipids of alga Scenedesmus obliquus grown under controlled conditions were separated and fractionated by column and thin-layer chromatography, and fatty acid composition of each lipid component was studied by gas-liquid chromatography (GLC). Total lipids were 11.17%, and neutral lipid, glycolipid and phospholipid fractions were 7.24%, 2.45% and 1.48% on a dry weight basis, respectively. The major neutral lipids were diglycerides, triglycerides, free sterols, hydrocarbons and sterol esters. The glycolipids were: monogalactosyl diglyceride, digalactosyl diglyceride, esterified sterol glycoside, and sterol glycoside. The phospholipids included: phosphatidyl choline, phosphatidyl glycerol and phosphatidyl ethanolamine. Fourteen fatty acids were identified in the four lipid fractions by GLC. The main fatty acids were C18:2, C16:0, C18:3(alpha), C18:1, C16:3, C16:1, and C16:4. Total unsaturated fatty acid and essential fatty acid compositions of the total algal lipids were 80% and 38%, respectively.