FATTY ACID COMPOSITION OF LIPIDS FROM BROILERS FED SATURATED AND UNSATURATED FATS

SUMMARY— The effect of feeding saturated fat (tallow) and unsaturated fat (safflower oil) to broilers on the change in fatty acid composition of lipids deposited in broiler tissues at 4, 6, 8, and 10 wk of age was determined. Fatty acids from raw and cooked skin, excluding that on the neck and third wing joint, breast meat, thigh meat, and abdominal fat were identified by using gas liquid chromatography. Fatty acids from water in which carcasses were cooked were also identified. The degree of unsaturation of fatty acids in these tissues wars influenced by the degree of unsaturated fatty acids in the diet and tended to assume the fatty acid composition of the diet. In some cases, however, the higher levels of certain fatty acids in depot fat was not present in broilers fed the higher levels in the diet. Fatty acids in the larger amounts in all broiler tissues were palmitic, stearic, ofeic, and linoleic but varied in amount among the different age broilers fed the same ration as well as different rations. In most cases there tended to be an inverse relationship between oleic and linoleic acids in the tissues. Lipids from cooked tissues contained a larger amount of 18-carbon unsaturated fatty acids than the other fatty acids combined. Fatty acids collected from cooking water were similar to those in cooked tissues. The presence of 13- and 25-carbon chain fatty acids noted in tissues of 4 wk-old broilers suggests a difference in the metabolism of fat in different age birds. Futher research is needed to substantiate this finding.     

PHYSICOCHEMICAL PROPERTIES OF EUROPEAN BAKERY MARGARINES WITH AND WITHOUT TRANS FATTY ACIDS

Physicochemical properties of commercially available European bakery margarines (cream margarines, cake margarines [CM] and puff pastry margarines [PPM]) containing and devoid of trans fatty acids (TFAs) were investigated. Studied physical properties were the solid fat content (SFC), dropping points (DPs), polymorphism, texture (hardness), plasticity and the melting profile by differential scanning calorimetry. Experimental results confirm that physical properties of the margarines corresponded with their application area. For example, SFC and DPs of PPM were higher than cream margarines and CM; they were also harder at 15C. Moreover, all the investigated physical properties were affected by the suppression of TFA in bakery margarines .

PRACTICAL APPLICATIONS

This study has shown that margarines present different physical properties with respect to their purposed application but also highlight changes that appear due to the absence of trans-fatty acids in the formulations. These changes can really affect the bakery abilities and will, finally, influence the quality of the bakery products.     

FATTY ACID COMPOSITION AND CONJUGATED LINOLEIC ACID CONTENT OF COW AND GOAT CHEESES FROM NORTHWEST ARGENTINA

ABSTRACT

In this study, we evaluated chemical characteristics, fatty acid composition and conjugated linoleic acid (CLA) content of cow and goat cheeses from Northwest Argentina. Similar chemical and fatty acid composition were determined in milk and cheese of both species. Palmitic, oleic and myristic acids were the most abundant fatty acids in dairy products. CLA level averaged 0.85 and 0.96 in milk and 0.76 and 1.04 g/100 g of fatty acids in cheese of cow and goat, respectively. Cis‐9,trans‐11 was the major isomer present in both species. Significant differences in CLA desaturase activity were observed, showing a value of 0.068 and 0.064 in milk, and 0.077 and 0.071 in cheese of cow and goats, respectively. Good nutritional properties were determined for cheeses of both species, which are fed on natural pasture during spring and summer seasons. Goat's cheese represents a higher source of CLA for human consumers than cow's cheese, offering from 156.6 to 222.6 mg/ 100 g of sample.

PRACTICAL APPLICATIONS

The present work shows the fatty acid composition and chemical characteristics of two fresh cheeses manufactured with cow and goat milk. Animals were fed on natural pasture during summer and spring seasons. It is known that pasture increases conjugated linoleic acid (CLA) concentration in milk fat, and the content in cheese is directly related to it. The CLA content of dairy products for the human consumers was analyzed, showing goat cheese with high polyunsaturated fatty acid content, including CLA. Cow and goat fresh cheese offer CLA as many ripening products of different countries, as cheddar or hard cheeses. Lipid composition of food is related to many illnesses, but some compounds are beneficial to human health. The main sources of CLA are milk and cheeses, and in Northwest of Argentina, no data are reported about it, where artisanal cheeses are consumed by the population. Therefore, the atherogenicity index was determined as well.     

PERFORMANCE CHARACTERISTICS AND FATTY ACID COMPOSITION OF PIGS FED A DIET WITH DOCOSAHEXAENOIC ACID

Market hogs were fed a ration from 22–42 days prior that contained the omega-3 fatty acid docosahexaenoic acid (DHA) supplemented at 0, 0.125 and 0.250 kg/pig in the form of the microalgae , Schizochythrum sp. There were no differences (P>0.05) between the average daily gain, feed consumption, or feed efficiency of the controls and those that received a DHA supplementation. Of the 21 fatty acids analyzed, the concentration of only five were affected by DHA supplementation. Muscles from the ham, loin, and shoulder of pigs that received 0.250 kg of DHA contained more eicosapentaenoate, docosahexaenoate, and docosapentaenoate n-6 and n-3 than either the controls or those that received 0.125 kg. Supplementation of DHA in the ration at 0.125 kg caused an elevation of docosapentaenoate n-6 and docosahexaenoate. These data suggest that addition of DHA to the diet can elevate the amount of this omega-3 fatty acid in pork with potential health benefits to consumers.     

不同颜色缅甸尖晶石的宝石学特征及其成份分析

采用可见光吸收光谱、紫外荧光及X射线能谱分析等测试手段，对产自缅甸的不同颜色尖晶石宝石学特征及成份进行研究分析。结果表明：不同颜色尖晶石的吸收带、荧光强度、微量元素组成及含量上具有不同特征。     

不同动物肝脏中脂肪酸成分分析

采用气相色谱法对7种动物肝脏中脂肪酸组成进行分析。以猪、羊、鸡、鸭、鲫鱼、草鱼和鹅的肝脏为材料,采用KOH-乙醇皂化,HCl-甲醇酯化的方法进行样品处理。实验结果表明,猪肝中有16种脂肪酸,鸡肝中有12种脂肪酸,羊肝中有18种脂肪酸,鸭肝中有14种脂肪酸,鲫鱼肝中有20种脂肪酸,草鱼肝中有22种脂肪酸,鹅肝中有19种脂肪酸。能快速、准确、可靠的满足动物肝中脂肪酸检测分析要求。     

抽油烟机回收油的脂肪酸组成变化特征研究

食用油在烹饪过程中挥发,会在抽油烟机系统中凝结。分别以花生油、葵花籽油、茶籽油、玉米油和调和油5种不同植物油为食用油进行烹饪试验,收集经抽油烟机系统凝结的油脂。通过测定抽油烟机回收油和相应未烹饪油的脂肪酸,来分析回收油脂肪酸组成变化特征。结果表明,回收油的脂肪酸种类和含量显著性差别于未烹饪油(P0.05)。回收油增加了C14∶0、C16∶1n7c短碳链脂肪酸,其饱和脂肪酸的含量增加了,不饱和脂肪酸含量减少了,其脂肪酸不饱和度明显降低,仅是未烹饪油的50%~61%。回收油中短碳链脂肪酸有增加的趋势,长碳链脂肪酸含量有减少的趋势,而且新增了食用油本底很少或没有的C18∶3n3c和EPA脂肪酸。回收油的品质也开始变化,有些回收油的脂肪酸已严重偏离了正常植物油的特征值。因此,抽油烟机回收油已不适合再食用,烹饪过程中应降低烹饪温度以减少食用油的变质。     

BARLEY DORMANCY AND FATTY ACID COMPOSITION OF LIPIDS ISOLATED FROM FRESHLY HARVESTED AND STORED KERNELS

The influence of kernel surface lipids on barley dormancy was investigated. Kernels with surface lipids extracted by chloroform:methanol (2:1) germinated nearly as well as Intact kernels subsequent to steeping in either distilled water or a solution of formaldehyde (ca 800 mg/l). Both water-sensitivity and innate dormancy were reduced in intact and surface-lipid extracted kernels stepped in formaldehyde when compared with kernels steeped in distilled water. Differences in fatty acid composition occurred in both surface and total kernel lipids of grain held in storage. However, compositional changes in fatty acids could not be used to predict kernel dormancy since increasing germination properties of kernels during the storage period were influenced by environmental conditions at time of harvest and varietal differences.     

TUDIES ON THE FATTY ACID COMPOSITION OF HOP EXTRACT

Studies on fatty acids composition of hop extract obtained from Vurtenberg hop by extraction with a threecomponent mixture was carried out. It has been established that the content of fatty acids in hop extract is 0.3% ±5%. Fatty acids composition was determined by Gas-chromatographic analysis. The presence of the following unsaturated fatty acids has been proven: C_16:1; C_18:1; C_18:2; C_18:3; C_20:1 which represent about 40% of the general content of fatty acids in the extract.     

INFLUENCE OF LOW FAT FISHMEAL ON FATTY ACID COMPOSITION AND SENSORY QUALITY OF PORK

Four groups of growing-finishing pigs, were fed low fat fishmeal together with an increased level of fish oil. Additional fish oil increased the content of long-chain n-3 fatty acids in subcutaneous fat and muscle when feeding up to 9 g fish oil kg^-1 diet. Sensory quality of fresh meat was not affected by the increased level of fish oil in diets but the intensity of off-flavor/odor and rancid flavor/odor of fat increased after six months of frozen storage. Partial least square regression of rancid flavor/odor after six months of frozen storage using the significant variables C20:1, C20:5 (EPA), C22:5 (DPA) and C22:6 (DHA) in subcutaneous fat gave correlation coefficients as high as 0.92. Based on these results, the use of low fat fishmeal is acceptable but the content of fish oil should be limited to 3 g fish oil kg^-1 diet for growing-finishing pigs.     

EFFECT OF FERMENTATION ON THE FATTY ACID CONTENT AND COMPOSITION OF CASSAVA TUBER MEAL

The effect of fermentation on the fatty acids (FA) content and composition of cassava tuber meal has been investigated. The major FA of the cassava tuber meal (CTM) lipid were oleic and palmitic acids. Other FA found in decreasing order were linoleic, linolenic, palmitoleic, stearic, myristic, pentadecanoic, heptadecanoic and nonadecanoic acids. Fermentation of the CTM resulted in substantial increases in the absolute quantities of the individual FA detected except linolenic acid. However fermentation did not alter the pattern of composition of the FA, but it caused increases in the composition of saturated FA and decreases in certain unsaturated ones. Stearic acid increased in composition by about 92.6% and pentadecanoic by about 50%. A reduction of about 72% of the linolenic acid and 24.2% of the palmitoleic acid composition were obtained in the fermented CTM lipid.     

温度对海洋微藻生长及脂肪酸组成的影响

研究了不同温度下,三角褐指藻和等鞭金藻生长及脂肪酸组成.结果表明,三角褐指藻的最适生长温度为20℃,而等鞭金藻的最适生长温度为25℃.无论是三角褐指藻的EPA还是等鞭金藻的DHA,均随着培养温度的升高而下降.低温有利于三角褐指藻积累EPA和PUFAs,但PUFAs含量（W/W）在10-20℃之间差异不显著（P＞0.05）.虽然等鞭金藻DHA含量随着温度的上升而下降,但PUFAs在20℃时含量（W/W）最高,为10.5%.不同海洋微藻不仅具有不同的生长温度,且最适PUFAs合成的温度也不同.