The quality properties and saturated and unsaturated fatty acid profiles of quail egg: the alterations of fatty acids with process effects

The nutritional composition (moisture, ash, crude protein, available carbohydrates, total lipids), energy value, some quality characteristics (yolk weight, albumen weight and shell weight), cholesterol level and fatty acid profiles of quail egg were determined (p<0.01). The protein content of quail egg was higher than laying hen's egg. The fatty acid composition of quail egg yolk consisted of 24 fatty acids including saturated fatty acids (C14:0, C16:0, C17:0, C18:0, C20:0, C22:0, C24:0), monounsaturated fatty acids (C15:1, C16:1, C17:1, C18:1n9, C18:1n7, C22:1n9, C24:1) and polyunsaturated fatty acids (C18:2n6t , C18:2n6c , C18:3n6, C18:3n3, C20:2, C20:3n6, C20:3n3, C20:4n6, C22:2, C20:5n3, C22:6n3). The total cholesterol level of quail egg was found to be 73.45+/-1.07 mg/100 g. Linoleic acid (C18:2n6c) (10.28%), arachidonic acid (C20:4n6) (1.92%) and cis-5,8,11,14,17-eicosapentaenoic acid (C20:5n3) (0.63%) were the major polyunsaturated fatty acids in the fatty acid content of quail egg yolk, whereas oleic acid (C18:1n9c) was the major monounsaturated fatty acid comprising 26.71% in the yolk. The palmitic acid (C16:0) and stearic acid (C18:0) levels were 16.62% and 6.89%, respectively. Total omega-3 was detected as 1.16% in raw egg whereas it was 0.82% in soft-boiled (rafadan) egg. The polyunsaturated fatty acid/saturated fatty acid proportion was 0.58 and 0.64 for raw and processed yolk, respectively.     

Detection of omega-3 fatty acid in designer eggs using hyperspectral imaging

Quantification of n-3 polyunsaturated fatty acids (PUFA) is an important aspect in quality control of designer eggs. Prediction of these fatty acids would be of value for egg grading stations. The aim of the present study was to evaluate the ability of hyperspectral imaging (HSI) to classify the eggs according their content in n-3 PUFA as a rapid and non-destructive technique. Furthermore, HSI was used to predict the content of n-3 PUFA in designer eggs. Normal eggs, eggs containing 75 mg and eggs containing 125 mg docosahexaenoic acid were purchased from a grocery store. After hyperspectral transmittance images were collected in the spectral region of 900–1,700 nm, the eggs were broken and analyzed chemically in order to measure fatty acid content. Regions of interest (ROIs) of about 3,000 pixels from each egg were selected. K-means analysis was performed to classify eggs into the three aforementioned types. The classification accuracy was 100%. A partial least-squares regression model was built and used to link the ROIs with results obtained from the chemical analysis. The correlation coefficients between the measured and predicted values of alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid were 0.94, 0.73 and 0.87, respectively. The root mean square error values for the validation sets were 38.65, 3.31 and 7.03, respectively. These results showed that HSI could be used both for discriminating the eggs between normal and designer eggs and for prediction of n-3 PUFA content in eggs.     

Comparative evaluation of essential fatty acid composition of mothers' milk of some urban and suburban regions of West Bengal,India

This study investigated the fatty acid composition of lipid present in breast milk of mothers residing in urban and suburban regions of West Bengal with special emphasis on n-6 and n-3 polyunsaturated fatty acids, which played a crucial role in the growth and development of neonates. Milk samples collected from 135 mothers of middle income group (average monthly income around ‘Rs 10,000/-’) were analysed by gas liquid chromatography after extraction and transmethylation to determine fatty acid composition. Information about the dietary intake of individual mothers was obtained through food frequency questionnaire. The fractions of n-6 and n-3 polyunsaturated fatty acids available in milk of urban mothers were 13.59 ± 0.94 and 3.65 ± 0.49, respectively, and in suburban mothers 12.74 ± 0.89 and 4.36 ± 0.39, respectively. The green leafy vegetables, fishes and vegetable oils were the major sources of essential fatty acids in the diet of the experimental groups of Bengali mothers. This study revealed a relationship between the alimentary habits of mothers and the concentration of essential fatty acids in breast milk of Bengali mothers.     

n-3及n-6多不饱和脂肪酸与乳腺癌关系的Meta分析

目的 系统评价n-3多不饱和脂肪酸(n-3PUFAs)、n-6多不饱和脂肪酸(n-6PUFAs)及其比例与乳腺癌发病风险的关系。方法 系统检索Pubmed、Embase、Web of Science、知网、万方等数据库截止至2022年1月1日有关n-3及n-6多不饱和脂肪酸与乳腺癌关系的研究,对最终纳入的文献进行数据提取与质量评价,采用Stata 15.1软件进行Meta分析。结果 共纳入33项针对n-3及n-6PUFAs和乳腺癌发病风险关联的观察性流行病学研究,其中队列研究14项,病例对照研究20项,共纳入研究对象1 077 178例,患者19 207例。Meta分析结果显示:n-3多不饱和脂肪酸(OR=0.933,95%CI:0.858～1.014)、n-6多不饱和脂肪酸(OR=1.018,95%CI:0.914～1.133)与乳腺癌发病风险无统计学关联(P>0.05),而较高的n-6/n-3PUFAs比值会显著增加乳腺癌的发病风险(OR=1.166,95%CI:1.047～1.299,P=0.005)。结论 n-6/n-3多不饱和脂肪酸的比值与乳腺癌的发病风险呈正相关,提示合理的膳食脂肪摄入比可能会降低乳腺癌的患病风险。而n-3及n-6多不饱和脂肪酸与乳腺癌发病风险的单独效应关系尚不明确,仍需更多前瞻性实验流行病学证据进行支持。     

N-3 fatty acids reduced trans fatty acids retention and increased docosahexaenoic acid levels in the brain

Introduction: The levels of docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (AA, 20:4n-6) are critical for the normal structure and function of the brain. Trans fatty acids (TFA) and the source of the dietary fatty acids (FA) interfere with long-chain polyunsaturated fatty acids (LC-PUFA) biosynthesis.

Objectives: The aim of this study was to investigate the effect of TFA supplementation in diets containing different proportions of n-9, n-6, and n-3 FA on the brain FA profile, including the retention of TFA, LC-PUFA levels, and n-6/n-3 PUFA ratios. These parameters were also investigated in the liver, considering that LC-PUFA are mainly bioconverted from their dietary precursors in this tissue and transported by serum to the brain. Also, stearoyl-CoA desaturase-1 (SCD1) and sterol regulatory element-binding protein-1c (SREBP-1c) gene expressions were evaluated.

Methods: Male CF1 mice were fed (16 weeks) diets containing different oils (olive, corn, and rapeseed) with distinct proportions of n-9, n-6, and n-3 FA (55.2/17.2/0.7, 32.0/51.3/0.9, and 61.1/18.4/8.6), respectively, substituted or not with 0.75% of TFA. FA composition of the brain, liver, and serum was assessed by gas chromatography.

Results: TFA were incorporated into, and therefore retained in the brain, liver, and serum. However, the magnitude of retention was dependent on the tissue and type of isomer. In the brain, total TFA retention was lower than 1% in all diets.

Discussion: Dietary n-3 PUFA decreased TFA retention and increased DHA accretion in the brain. The results underscore the importance of the type of dietary FA on the retention of TFA in the brain and also on the changes of the FA profile.     

The health effects of dietary unsaturated fatty acids

• 2.1 The chemistry of fatty acids
• 2.2 Digestion, absorption and metabolism
• 2.3 Functions of unsaturated fatty acids

3 Unsaturated fatty acids in the UK diet

• 3.1 Sources of fat in the diet
• 3.2 Dietary recommendations for fat
• 3.3 Intakes of unsaturated fatty acids
• 3.4 Major contributors to unsaturated fatty acid intake
• 3.5 Trends in intake

4 Unsaturated fatty acids in health and disease

• 4.1 Unsaturated fatty acids and cardiovascular disease
• 4.2 Unsaturated fatty acids and diabetes
• 4.3 Unsaturated fatty acids and cancer
• 4.4 Unsaturated fatty acids and inflammatory conditions
• 4.5 Unsaturated fatty acids in fetal and infant development
• 4.6 Unsaturated fatty acids and cognitive function and behaviour
• 4.7 Emerging aspects of unsaturated fatty acids and health

5 Unsaturated fatty acids and public health

• 5.1 Labelling of unsaturated fatty acids
• 5.2 Are current UK recommendations adequate?
• 5.3 Opportunities to increase intake of long chain n‐3 PUFAs
• 5.4 Implications of optimising intakes of unsaturated fatty acids

6 Conclusions

Acknowledgements

References

Appendix 1

Summary Fat provides energy; indeed it is the most energy dense of all the macronutrients, with 1 g providing 37 kJ (9 kcal). However, the constituent parts of fat, fatty acids, are required by the body for many other functions than simply as an energy source, and there is an increasing awareness of the potential health benefits of specific types of fatty acids. Fatty acids are long hydrocarbon chains, with a methyl group at one end (the omega or n‐end) and an acid group at the other. Unsaturated fatty acids are hydrocarbon chains containing at least one carbon–carbon double bond; monounsaturated fatty acids contain one double bond, and polyunsaturated fatty acids (PUFAs) contain many double bonds. The position of the double bond relative to the omega end determines whether a PUFA is an n‐3 (omega 3) or an n‐6 (omega 6) fatty acid. Most fatty acids can be synthesised in the body, but humans lack the enzymes required to produce two fatty acids. These are called the essential fatty acids and must be acquired from the diet. In humans, the essential fatty acids are the n‐3 PUFA α‐linolenic acid and the n‐6 PUFA linoleic acid. Although humans can elongate dietary α‐linolenic acid to the long chain n‐3 PUFAs eicosapentaenoic acid and docosahexaenoic acid, the rate of synthesis may not be sufficient to meet requirements, and it is, therefore, recommended that good sources of these fatty acids, namely, oil‐rich fish, are also included in the diet. Fat is found in most food groups, and foods containing fat generally provide a range of different fatty acids, both saturated and unsaturated. In the UK, the major dietary sources of unsaturated fatty acids include meat & meat products, cereals & cereal products and potatoes & savoury snacks; primarily as a result of the vegetable oil used in processing. Recommended intakes of both total fat and the different types of fatty acids have been set for the UK population, and it is possible to monitor fat intake from the data collected in nationwide dietary surveys. As a population, we are not currently meeting these recommendations, so there is still scope for dietary change. In Western diets, n‐6 fatty acids are the predominant PUFAs, and this is in line with current dietary advice to consume a minimum of 1% energy as n‐6 PUFAs and 0.2% energy as n‐3 PUFAs. The balance of n‐3 and n‐6 PUFAs in Western diets has changed substantially over the last 100 years or so, and as the two families of PUFAs share a common metabolic pathway, concerns have been raised that this might be detrimental to health; what is becoming increasingly clear is that both n‐3 and n‐6 PUFAs have independent health effects in the body, and as intakes of the n‐6 PUFAs are within the guidelines for a healthy diet, concerns about the n‐6 to n‐3 ratio are driven by low intakes of n‐3 rather than high intakes of n‐6. Currently in adults n‐6 PUFAs contribute to 5.3% energy. Detecting associations between components of the diet and risk of various diseases is notoriously complex and in many cases, the evidence is still accumulating. Cardiovascular disease, characterised by hardening and narrowing of blood vessels and/or the development of blood clots, is one of the leading causes of mortality and morbidity worldwide. The type and total amount of dietary fat has a clear part to play in affecting an individual’s disease risk, yet the precise mechanisms by which unsaturated fatty acids reduce cardiovascular disease risk are still unclear. A number of mechanisms whereby dietary fatty acids could influence the progression of cardiovascular disease and its risk factors have been identified. These include effects on blood lipid concentrations, blood pressure, inflammatory response, arrhythmia and endothelial function, along with many other effects, both known and as yet undefined. A well‐established risk factor for cardiovascular disease is an elevated plasma low density lipoprotein (LDL) cholesterol concentration. Replacing saturated fatty acids with either monounsaturated fatty acids or n‐6 PUFAs reduces LDL (the ‘bad’) cholesterol, and so reduces the risk of developing the disease. Unsaturated fatty acids, such as linoleic acid or monounsaturated fatty acids, also slightly raise high density lipoprotein (HDL) (the ‘good’) cholesterol, which assists in the removal of triacylglycerols from the bloodstream. Interest in the health effects of the long chain n‐3 PUFAs found in fish oils is also increasing. There is strong supportive, but not yet conclusive, evidence that these fatty acids protect against fatal heart disease. On the basis of this conclusion, in 2004 the Scientific Advisory Committee on Nutrition advised the UK government to adopt the population‐wide dietary recommendation to eat at least two portions of fish per week, of which one should be oil‐rich, equivalent to 0.45 g of the long chain n‐3 PUFAs per day. In recent years, the potential health benefits of α‐linolenic acid has attracted attention, and evidence is mounting on the role that this n‐3 fatty acid may play in preventing the progression of cardiovascular disease, although it is currently unclear what, if any, association exists. Brain cells are especially rich in certain long chain PUFAs. This has led to the suggestion that dietary status of these long chain fatty acids might influence cognitive function and behaviour. Research in this field is still in its early stages, but there is a small amount of evidence to suggest improvements in cognitive function following fatty acid supplementation. In contrast, it is well established that pregnant women must have an adequate supply of the long chain n‐3 PUFAs before and throughout pregnancy and lactation to support normal growth, neurological development and cognitive function of the baby. As n‐6 PUFAs are more abundant in the diet, achieving an adequate intake is less problematic. However, this is not the case for the n‐3 PUFAs; increasing fish consumption beyond two servings of oil‐rich fish per week or relying on fish oil supplementation is not appropriate during pregnancy due to the potential problems associated with heavy metal contamination of fish, or the high vitamin A level in some fish oil supplements. Unsaturated fatty acids have also been associated with a number of other diseases and although the evidence is by no means conclusive, it is an area that is attracting a huge amount of interest. Dietary fat affects a number of different metabolic pathways, including those involved with glycaemic control, so the types and amounts of dietary fat may have a role to play in the management of type 2 diabetes. Unsaturated fatty acids may also be associated with a reduced risk of developing certain cancers, including cancers of the colon, breast and prostate, although currently the level of evidence is not deemed sufficient by authoritative bodies, such as the World Cancer Research Fund, World Health Organization and the Department of Health, to make any specific dietary recommendations. There are a number of inflammatory conditions, such as asthma, Crohn’s disease and arthritis, which could potentially be alleviated by dietary modification. The fatty acid composition of cell membranes can be altered by consumption of both n‐3 and n‐6 PUFAs, and this can result in reduced inflammatory activity. However, whether this effect brings about a significant reduction in clinical symptoms is still unclear. It is also important to note that there are concerns that the beneficial effects on certain disease outcomes are only observed with very high intakes of unsaturated fatty acids, which could realistically only be achievable by supplementation. Few nutritionists would be comfortable recommending supplement use as the only alternative to fish, as this can be expensive and goes against the idea that all the nutrients that our bodies require can be obtained from the food that we eat if the right choices are made. Unsaturated fatty acids are now a nutritional hot topic, and their presence in foods has attracted both public and industrial interest. There is currently no specific legislation to control the use of health claims relating to the fatty acid content of foods. However, a European Union (EU) Directive is expected imminently which will formally set down the criteria that a product will have to meet in order to make any nutrition or health claim. With regards to the current recommendations, those for the UK are in line with those around the world. However, as a population, we need to increase our consumption of long chain n‐3 PUFAs and decrease intake of saturated fatty acids. To facilitate this, food technologists are looking at ways in which the fatty acid profile of a food can be modified in order to bring dietary improvements without requiring a major change in dietary habits. However, public health messages surrounding the optimum intakes of fatty acids must be clear and consistent to ensure that a favourable change in the fatty acid profile of the UK diet occurs.     

孕期不同膳食模式对膳食脂肪酸含量及母初乳脂肪酸组成的影响

【目的】研究中国两种不同膳食模式地区膳食脂肪酸(fatty acid,FA)含量的差异,并探讨这种差异对母初乳脂肪酸组成的影响。【方法】对传统内陆膳食(常州)和海洋膳食(温州)地区孕晚期孕妇进行7d膳食调查,根据《2002中国食物成份数据》中的食物脂肪酸含量数据计算出膳食脂肪酸含量;并通过随访这些孕妇收集5d母初乳样本,采用高效毛细气相色谱分析技术检测5d母初乳的脂肪酸组成。【结果】常州与温州两地孕母摄入的膳食种类存在差异,温州地区孕母摄入的海洋食品远大于常州地区。常州地区孕母膳食脂肪酸中亚油酸(linoleic acid,LA)和α-亚麻酸(α-linolenic acid,ALA)含量均高于温州地区;而二十二碳六烯酸(docosahexaenoic acid,DHA)和二十碳五烯酸(eicosap-entaenoic acid,EPA)含量均低于温州地区;花生四稀酸(arachidonic acid,AA)含量则未见显著差异。两地膳食脂肪酸组成中LA、ALA、AA以及DHA的差异同样反应在5d母初乳中,但两地5d母初乳中的EPA含量差异无显著性。【结论】膳食模式不同的两个地区,其孕母的膳食脂肪酸含量存在差异,且这种差异可在母初乳脂肪酸组成中得到体现。     

Fatty acid composition of frequently consumed foods in Turkey with special emphasis on trans fatty acids

Fatty acid compositions of frequently consumed foods in Turkey were analyzed by capillary gas chromatography with particular emphasis on trans fatty acids. The survey was carried out on 134 samples that were categorized as meat products, chocolates, bakery products and others. The meat products except chicken-based foods have trans fatty acids, arising as a result of ruminant activity, with an average content of 1.45 g/100 g fatty acids. The conjugated linoleic acid content of meat and chicken doner kebabs were found higher than other meat products. Chocolate samples contained trans fatty acids less than 0.17 g/100 g fatty acids, with the exceptional national product of chocolate bars and hazelnut cocoa cream (2.03 and 3.68 g/100 g fatty acids, respectively). Bakery products have the highest trans fatty acid contents and ranged from 0.99 to 17.77 g/100 g fatty acids. The average trans fatty acid contents of infant formula and ice-cream, which are milk-based products, were 0.79 and 1.50 g/100 g fatty acids, respectively. Among the analyzed foods, it was found that coffee whitener and powdered whipped topping had the highest saturated fatty acid contents, with an average content of 98.71 g/100 g fatty acids.     

鱼油类保健品中不饱和脂肪酸的气相色谱及质谱检测研究

[目的 ]　研究鱼油中多不饱和脂肪酸含量的确证分析方法。　 [方法 ]　利用毛细管气相色谱以及气质联用技术检测鱼油中多不饱和脂肪酸 (如DHA、EPA、DPA)的含量。　 [结果 ]　建立了用毛细管色谱柱进行有效分离 ,保留时间定性 ,以面积归一法或外标法定量 ,以GC -MS法进行确证的有效方法 ,同时对标准质谱库 (NIST库 )中没有的成分 (如DPA、DHA)建立了标准谱图。　 [结论 ]　本方法能满足对鱼油产品中不饱和脂肪酸的分析要求 ,具有简便、快速、可靠的特点     

不同年龄阶段小鼠脑聚集二十二碳六烯酸及脂肪酸去饱和酶的变化

【目的】 探讨生命早期不同年龄阶段脑摄取、聚集二十二碳六烯酸(DHA)(C22:6n-3)及相关去饱和酶的变化。 【方法】 使用6~8周龄清洁级C57BL/6J雌性小鼠,分别给予n-3 多不饱和脂肪酸(n-3 PUFAs)缺乏饲料和含n-3 PUFAs饲料喂养6周,然后雌雄合笼交配繁殖,新生仔鼠分别于生后7、21 d和42 d时取血、脑和肝脏。采用甲酯化-气相色谱分析对血浆、脑和肝脏中脂肪酸谱进行分析;采用荧光定量PCR方法对脑和肝脏中脂肪酸去饱和酶1(FADS1)和脂肪酸去饱和酶2(FADS2)基因mRNA表达进行检测。 【结果】 对不同年龄小鼠组织脂肪酸的比较发现,脑中DHA和总n-3 PUFAs含量在两种不同饲料组均随年龄增加而升高;而肝中的含量则随年龄增加而降低。与n-3 PUFAs缺乏组相比,饲料中添加n-3 PUFAs可使仔鼠生后7、21 d和42 d时脑和肝脏中DHA和总n-3 PUFAs含量均显著升高;升高的程度在脑组织中随年龄增加而降低,而在肝脏组织中则不随年龄变化。对不同年龄段FADS表达的比较发现,FADS1和FADS2 mRNA在脑组织中的表达量于42 d时显著高于7 d和21 d,而在肝组织中的表达量于各年龄段之间无显著性差异。与n-3 PUFAs缺乏组相比,饲料中添加n-3 PUFAs可使仔鼠生后7 d和21 d时脑组织FADS1和FADS2表达水平显著降低,而42 d时的表达无变化;肝组织中这两种酶mRNA水平在7 d和21 d时无变化,42 d时FADS1显著降低。 【结论】 发育期脑对DHA的聚集需求随着年龄增大而逐渐减少;FADS在脑中的表达水平随年龄增大而升高。同时,饲料n-3 PUFAs缺乏状态对脑聚集DHA以及FADS的影响在年龄小时更明显。     

Role for fatty acid binding protein in the regulation of hepatic lipogenesis by dietary linoleic acid

The effect of added dietary ethyl palmitate or ethyl linoleate on hepatic lipogenic enzymes and the amount of hepatic fatty acid binding protein was examined in meal-fed rats. Dietary linoleate reduced the activities of fatty acid synthetase, glucose-6-phosphate dehydrogenase, NADP-malic enzyme, ATP-citrate lyase, and the amount of fatty acid binding protein compared to rats fed a fat-free or palmitate supplemented diet. The possible role of fatty acid biding protein in the regulation of lipogenesis by dietary fat is discussed.     

不饱和脂肪酸的气相色谱法同时测定

目的：建立不饱和脂肪酸含量的测定方法。方法：采用衍生气相色谱程序升温同时测定4个成分。结果：平均回收率为95％～105％，RSD为0．39％～2．81％。结论：该方法可以用于保健品及食品中不饱和脂肪酸的测定。     

The effects of season and sex on fat,fatty acids and protein contents of Sepia officinalis in the northeastern Mediterranean Sea

The effects of season and sex on the fatty acids (FAs) and proximate compositions of the mantle of the mature common cuttlefish were evaluated. The results of the proximate composition showed that the lowest lipid content was obtained from females in winter (0.74%), whereas the highest level of lipid was found in males in autumn (0.94%; p < 0.05). The protein levels of the mantle of the mature male of common cuttlefish were significantly higher (p < 0.05) than those found in female specimens. The FA compositions of each sex for all seasons ranged from 29.4% to 32.5% saturated FAs, 8.7–11.1% monounsaturated FAs and 48.2–54.6% polyunsaturated fatty acids (PUFAs). The proportions of n-3 PUFAs (44.0–50.6%) were higher than n-6 PUFAs (3.4–4.3%) regardless of sex and seasons. The levels of eicosapentaenoic acid in the mature common cuttlefish mantle in spring, autumn and winter were 15.9–17.8%, 16.3–17.2% and 15.7–16.8% while those of docosahexaenoic acid were 32.5–33.0%, 27.5–29.0% and 28.7–31.1%, respectively.     

Omega-3 polyunsaturated fatty acids and cognition throughout the lifespan: A review

Abstract

With increasing awareness of the effects of nutrition on physical and mental health, researchers have begun to further investigate the benefits of omega-3 polyunsaturated fatty acids (n-3 PUFA) on health and the brain; however, these benefits remain unclear across different age groups.

Objectives

The purpose of this article is to summarize the current evidence on the cognitive effects of n-3 PUFA throughout the lifespan.

Methods

An exhaustive review of the literature on the effects of n-3 PUFA on various aspects of cognition, across the lifespan, was conducted.

Results

The research suggests that n-3 PUFA positively affect pre-natal neurodevelopment; however, this cognitive-enhancing effect might diminish post-natally with maturation, as no research on child populations has clearly tied dietary n-3 PUFA to improved cognitive skills. Overall, few studies have examined the cognitive effects of n-3 PUFA through childhood, young adulthood, and middle age. At later ages, multiple studies found evidence suggesting that n-3 PUFA can protect against neurodegeneration and possibly reduce the chance of developing cognitive impairment.

Discussion

Age groups central to the lifespan require further investigation into the effects that n-3 PUFA might have on their cognitive skills. The research examining the extremities of the lifespan provides evidence that n-3 PUFA are essential for neurodevelopment and cognitive maintenance in older adulthood. Future research must develop more consistent methodologies, as variable dosages, supplementation periods, and cognitive measures across different studies have led to disparate results, making the evidence less comparable and difficult to synthesize.     

Enrichment of n‐3 fatty acids and conjugated linoleic acid in beef: ProSafeBeef

ProSafeBeef is a 5‐year integrated project funded by the European Commission under the sixth Framework Programme. The overall aim is to advance beef safety and quality across Europe and the work programme spans seven integrated “pillars”. Pillar 3 is concerned with producing safe beef and beef products with enhanced nutritional and eating quality characteristics. A particular focus is on the development of strategies to enhance the concentrations in beef of those fatty acids considered to be of benefit to human health, without causing a detrimental effect on the appearance, shelf‐life or eating quality of the beef. There is accumulating evidence of the importance of long‐chain n‐3 (omega‐3) polyunsaturated fatty acids (PUFAs) for human health and disease prevention, and also evidence from experimental studies that has shown anticarcinogenic, antiatherogenic, and anti‐obesity effects of two isomers of conjugated linoleic acid (CLA). Based on this evidence, the major focus of research efforts to improve the nutritional value of beef has been on increasing the concentration of the n‐3 PUFAs and CLA. Considerable progress has been made within pillar 3 of ProSafeBeef to meet this aim, primarily by manipulating the diet of cattle. Fundamental information on ruminal lipid metabolism and on the control and/or prevention of ruminal hydrogenation of dietary lipids arising from research within ProSafeBeef will facilitate the production of beef with a ‘healthier’ fatty acid profile. Moreover, strategies will be defined for industry on how to optimise nutritional and sensory properties and oxidative quality of beef products, by combining the nutritional enhancement made in the live animal together with target levels of functional ingredients to be added during processing.     

Comparison of fatty acid and proximate compositions of the body and claw of male and female blue crabs (Callinectes sapidus) from different regions of the Mediterranean coast

Fatty acid and proximate compositions of the body and claw of male and female blue crabs from Akyatan Lagoon and Hurma strait were investigated. Male blue crab meat had a higher protein and fat content, and lower moisture and ash content, than that of the female from Akyatan Lagoon. Moreover, there were variations of protein and fat amounts in both female crab meats between Akyatan Lagoon and Hurma strait. The dominant saturated fatty acids were palmitic acid (16:0; range from ～12% to 15%) and stearic acid (18:0; range from ～7.5% to 16.1%) for all samples. The total monounsaturated fatty acid content in the body of female crabs from Akyatan Lagoon was higher than those of Hurma Strait (22.04% versus 7.55%). There were no statistically significant differences (P >0.05) between eicosapentaenoic acid concentrations in body meat of the male crab than those of female crab meat from Akyatan Lagoon (P<0.05). Docosahexaenoic acid contents were different between the body meat of male crabs from Akyatan Lagoon and those of female crabs from Hurma strait. The total n3 was detected as 27.33% in body meat whereas it was 24.39% in claw meat of the male crab from Akyatan Lagoon. Those values were almost similar in the body and claw meat of female crab from Akyatan Lagoon.     

外源性脂肪酸对结肠癌细胞生长的影响及其可能机制

目的：探讨八种外源性脂肪酸对人结肠癌细胞生长的影响及其作用机制。方法：体外实验中应用MTT法观察外源性脂肪酸对细胞生长的影响，并对细胞脂质过氧化反应产物丙二醛含量进行了测定。结果：多不饱和脂肪酸可抑制结肠癌细胞生长，饱和及单不饱和脂肪酸作用不明显，八种脂肪酸对正常成纤维细胞没有明显抑制作用。多不饱和脂肪酸可引起细胞内丙二醛含量升高。结论：多不饱和脂肪酸可选择性抑制肿瘤细胞生长，脂质过氧化反应增强，可能是其主要作用机制。     

Validation of a short questionnaire to qualitatively assess the intake of total fat, saturated, monounsaturated, polyunsaturated fatty acids, and cholesterol

Background To validate a self‐administered 20‐item short questionnaire (SQ) for classifying individuals according to their intake of total fat, saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA), as well as cholesterol. Methods The SQ was sent to a randomly selected subsample of 300 participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) in Heidelberg. The SQ was sent back by 244 participants (52.5% women, 47.5% men). Intake of total fat, SFA, MUFA, PUFA, and cholesterol was calculated from a 148‐item food frequency questionnaire (FFQ). The intake was compared with the scores computed from the SQ. Results Spearman's correlation coefficient between the intake estimated from the FFQ and the score from the SQ ranged from r = 0.29 (PUFA) to r = 0.56 (cholesterol). When the participants were assigned to quartiles of intake according to both methods 29–42% were classified into the same quartile, 1–7% of the participants were grossly misclassified. Conclusions The SQ demonstrated a good validity with respect to SFA and cholesterol and an acceptable validity with respect to total fat and MUFA, while the results are less good for PUFA. The SQ can be used to classify persons according to their intake into categories of intake.