脂肪真是那么可怕吗

脂肪留给人们的印象通常是不好的,谈“胆固醇”色变似乎已经上升到了谈“脂肪”色变的程度。毕竟,高脂膳食已被证明是患某些所谓“社会文明病”如心脏病、癌症和肥胖的危险因素这一事实,足以使脂肪将其坏名声留存于公众的意识中。然而,脂肪真是那么可怕吗?对这一问题还须辨证地来看。     

吃油要讲究脂肪酸平衡

吃多少油?吃什么油?怎样选购和保管油?怎样用油才科学?这是大家都关心的问题。2004年我国人均食用植物油的消费量是13·5公斤,即人均月消费量为1公斤多。加上鸡鸭鱼肉的动物性脂肪的消费,人均月膳食脂肪(从食品中所摄入的总脂肪量)为2公斤左右。从我国人民的健康状况看,我认为人均月2公斤膳食脂肪已经满足人体需要了。我国有些地方普遍食油过多,这与心血管病等疾病发病率高是有关系的。此外,吃油时脂肪酸平衡的问题也是需要重视的。脂肪酸平衡是怎么一回事呢?油脂的学名叫“甘油三酯”,由甘油和脂肪酸组成。脂肪酸的种类很多(如根据饱和程度…     

油脂营养

<正>人们食用脂肪是为提供本身所需热量、必需脂肪酸及吸收油溶性维生素,当然也为享用烹饪之美味、膳食热量30～40％由脂肪提供,多数脂肪系由16～18碳三甘油酯所组成,脂肪必须先在胃肠系统水解战单甘油酯、游离脂肪酸、甘油后,才能在肠道被吸收,在肠细胞中长链脂肪酸与乳糜微粒再酯化结合。然后经淋巴系统分泌入血液。因各个长链脂肪酸的碳链长,双键数、几何组合形状不同,故而不同长链脂肪酸具有各自不同物理性能,虽这些物理性能随长链脂肪酸种类,数量不同而异,而且,还受其他一些因素影响。如所添加抗氧化剂内容、遗传所育成特性等。 现在对膳食脂肪质量产生兴趣,主要是因为膳食脂肪种类及其数量与某些病症。特别是冠心病发生率和死亡率呈有一定相关性。据研究表明,饱和脂肪提供膳食热量比重与中、老年人冠心病死亡率有密切关系。 由于食用高含饱和脂肪膳食会提高血清胆固醇水平。就有理由认为膳食中饱和脂肪含量对冠心病有直接关系。门新克与凯塔最近对27份膳食研究报告作间位分析,以说明膳食脂肪替代醣类对血清脂蛋白组份影响。     

中国15省(区、直辖市)老年居民膳食脂肪摄入状况

目的:分析2015年中国15省(区、市)老年居民膳食脂肪摄入状况。方法:数据来自2015年中国居民营养状况变迁的队列研究。选取参加本次调查并有完整的调查数据的60岁以上老年居民作为研究对象,分析研究对象膳食脂肪摄入量、供能比和食物来源,并与《中国居民膳食指南(2016版)》膳食脂肪推荐摄入量进行比较。结果:我国15省(区、市)老年居民2015年膳食脂肪摄入量为69. 2g/d、膳食脂肪供能比为34. 2%、膳食脂肪供能比超过30%的人群比例为61. 7%;调查人群中来源于动物性食物、动物油、植物油和植物性食物的脂肪占膳食脂肪总量为32. 8%、3. 8%、43. 3%和20. 1%。结论:中国15省(区、市)老年居民膳食脂肪摄入量较高,脂肪供能比已超过《中国居民膳食指南(2016版)》膳食脂肪推荐摄入量的要求,应控制含脂肪高的食物的摄入量。     

充分发挥膳食纤维的保健作用

我国居民以植物性食物为主,一般不会缺乏膳食纤维。但是近年来,人们的饮食习惯发生了很大的变化,有些地区已出现了摄入纤维不足现象,加上脂肪与蔗糖摄入量的增加,肥胖症、糖尿病、动脉硬化、冠心病和恶性肿瘤的发病率有所提高。而且,这些疾病在各年龄     

断奶食品中纤维容量的研究

一、前 言 近年来膳食纤维成了人类营养非常感兴趣的问题,因为有些已被证明有益于健康,而另一些则尚属于假设性。这主要对成人或学龄儿童的营养而言;而婴儿和学龄前儿童的纤维问题却与成人的情况相反,提出的重要营养见解主要是其潜在的不利方面而不是其有利方面。在科罗拉多州大学由美国农业部/国际开发署(USDA/AID)资助的廉价挤压蒸煮计划(LEC)的研究中,纤维是特别     

健康饮食新观念

现代人解决了温饱问题后,也开始渐渐地注重起饮食的“营养”问题,但是很多人的营养知识还很贫乏,不知道吃什么和怎么吃更具“营养”,更有利于健康。有专家分析,现代都市人的膳食结构还存在较大的问题,如不少人膳食中的热卡和脂肪含量过高;有的偏食精细食物,忽视粗粮和蔬菜对人体健康的重要性。不良的饮食结构也带来了一系列的营养性疾病,如肥胖症、高血脂、高血压、动脉硬化、糖尿病、肿瘤及营养不良等发病率都有所上升。与饮食密切相关的心脑血管病和恶性肿瘤已成为导致人们死亡的两大主要病因,可见饮食与健康的关系已越来越为密切。那么,现代人的健康     

生活中的“长生果”——普通却不平凡的花生

<正>花生—平凡却不普通,其富含蛋白质、有益脂肪、膳食纤维、多种维生素、氨基酸及微量元素。2016年冬天,美国花生协会精选了健康美味的花生食品,登陆中国电商平台,为花生爱好者带来纯正的美国花生。花生中含有大量的蛋白质和脂肪,而其所含的脂肪多为有益脂肪,即不饱和脂肪酸。同时,花生还含有维生素、微量元素与膳食纤维,能够充分补充人体所需的营养。     

超声波辅助浸提小麦膳食纤维及其理化性质研究

采用超声波辅助浸提法制备小麦麸皮可溶性物质和不溶性膳食纤维,并研究了不同干燥方式对不溶性膳食纤维理化性质的影响。在膨胀力方面,经过低温真空干燥的膳食纤维大于经过真空冷冻干燥的;在吸附脂肪方面,经过低温真空干燥的膳食纤维小于经过真空冷冻干燥的,而且小麦膳食纤维吸附饱和脂肪的能力明显强于吸附不饱和脂肪的能力。在吸附亚硝酸根方面,受体系的pH值影响较大,在pH值为7时,小麦膳食纤维基本不吸附亚硝酸根;而在pH值为2时,溶液中残留的亚硝酸根的含量随时间呈现明显减小的趋势,低温真空干燥处理的吸附亚硝酸盐的能力强于冷冻真空干燥所制备的膳食纤维。     

槲皮素降脂减肥机制研究进展

肥胖已成为全球性的流行病,并且与糖尿病、心血管疾病、非酒精性脂肪肝等代谢综合征的发生密切相关,寻求有效安全的减肥药物成为人们的共同愿望。槲皮素是膳食中来源丰富的类黄酮物质,研究表明其具有降脂减肥的作用。本文综述了近年槲皮素减肥作用的机制研究,即抑制膳食能量营养成分吸收、改善机体脂肪代谢、抑制甘油三酯的积累、促进脂肪细胞凋亡和调节脂肪因子释放等方面的研究。     

食品中的反式脂肪酸及其危害

近年来的研究表明摄入含有大量反式脂肪酸的膳食对心血管系统和胎儿的生长发育等方面有不良影响。本文从反式脂肪酸的食物来源和形成机理及其与生长发育和心血管疾病的关系等方面对目前国内外的研究状况作一综述。     

Recent Research Trends on the Enzymatic Synthesis of Structured Lipids

Structured lipids (SLs) are lipids that have been chemically or enzymatically modified from their natural biosynthetic form. Because SLs are made to possess desired nutritional, physicochemical, or textural properties for various applications in the food industry, many research activities have been aimed at their commercialization. The production of SLs by enzymatic procedures has a great potential in the future market because of the specificity of lipases and phospholipases used as the biocatalysts. The aim of this review is to provide concise information on the recent research trends on the enzymatic synthesis of SLs of commercial interest, such as medium‐ and long‐chain triacylglycerols, human milk fat substitutes, cocoa butter equivalents, trans‐free or low‐trans plastic fats (such as margarines and shortenings), low‐calorie fats/oils, health‐beneficial fatty acid‐rich fats/oils, mono‐ or diacylglycerols, and structurally modified phospholipids. This limited review covers 108 research articles published between 2010 and 2014 which were searched in Web of Science.     

食品中反式脂肪酸的风险评价

根据风险评价理论,从反式脂肪酸来源、吸收代谢方式、对人体健康的危害及中国居民膳食调查和各种食品中反式脂肪酸暴露水平,推算出现在中国居民反式脂肪酸暴露量低于安全摄入剂量,表明中国食品中反式脂肪酸风险尚属可接受范围;最后从降低食物中反式脂肪酸、建立反式脂肪酸的标签制度及实施限量标准两方面提出了风险管理措施。     

Socio-economic dynamics and innovative technologies affecting health-related lipid content in diets: Implications on global food and nutrition security

The recent increase in human population coupled with rural-to-urban migration has led to challenges in managing a balanced diet in both food ‘secure’ and food ‘insecure’ regions. As a result of this geographic phenomenon, the human population continues to suffer from caloric-related conditions and diseases, including obesity and coronary heart diseases. In addition, fat and fatty acid composition of the diet has come under severe attack from the media and different human nutrition corridors in the past as they have been implicated in aiding the increase in cases of coronary heart diseases despite their important roles in cellular functions. In this view, fat and fatty acids is of great significance to the modern society, which aims at balancing their dietary proportions for efficient functionality of the human body systems. To improve food and nutrition, understanding the physiological function of the body and biochemical function of the fatty acids and polar lipids and getting a clearer view of the socio-economic aspects surrounding food consumption is also important. However, to further enhance the utilisation of fats accessed from diets, it is important to highlight significant current innovative technologies used to improve food fatty acid profiles and the influence of media on dietary and food consumption patterns. This review discusses the significance of health-related fatty acids, socio-economic aspects governing their presence in food and consumption, and how all these factors have a bearing on achieving the goal of human health, well-being and food and nutrition security.     

Tropical oils: nutritional and scientific issues.

Individually and in combination with other oils, the tropical oils impart into manufactured foods functional properties that appeal to consumers. The use of and/or labeling in the ingredient lists give the impression that these oils are used extensively in commercially processed foods. The estimated daily intake of tropical oils by adult males is slightly more than one fourth of a tablespoon (3.8 g), 75% of which consists of saturated fatty acids. Dietary fats containing saturated fatty acids at the beta-position tend to raise plasma total and LDL-cholesterol, which, of course, contribute to atherosclerosis and coronary heart disease. Health professionals express concern that consumers who choose foods containing tropical oils unknowingly increase their intake of saturated fatty acids. The saturated fatty acid-rich tropical oils, coconut oil, hydrogenated coconut oil, and palm kernel oil, raise cholesterol levels; studies demonstrating this effect are often confounded by a developing essential fatty acid deficiency. Palm oil, an essential fatty acid-sufficient tropical oil, raises plasma cholesterol only when an excess of cholesterol is presented in the diet. The failure of palm oil to elevate blood cholesterol as predicted by the regression equations developed by Keys et al. and Hegsted et al. might be due to the dominant alpha-position location of its constituent saturated fatty acids. If so, the substitution of interesterified artificial fats for palm oil in food formulations, a recommendation of some health professionals, has the potential of raising cholesterol levels. A second rationale addresses prospective roles minor constituents of palm oil might play in health maintenance. This rationale is founded on the following observations. Dietary palm oil does not raise plasma cholesterol. Single fat studies suggests that oils richer in polyunsaturated fatty acid content tend to decrease thrombus formation. Anomalously, palm oil differs from other of the more saturated fats in tending to decrease thrombus formation. Finally, in studies comparing palm oil with other fats and oils, experimental carcinogenesis is enhanced both by vegetable oils richer in linoleic acid content and by more highly saturated animal fats. The carotenoid constituents of red palm oil are potent dietary anticarcinogens. A second group of antioxidants, the tocotrienols, are present in both palm olein and red palm oil. These vitamin E-active constituents are potent suppressors of cholesterol biosynthesis; emerging data point to their anticarcinogenic and antithrombotic activities. This review does not support claims that foods containing palm oil have no place in a prudent diet.     

The Contribution of Modern Margarine and Fat Spreads to Dietary Fat Intake

The study of dietary fat consumption and its resultant effects on human health has been one of the most investigated topics in the field of human nutrition. Based on the results obtained from such studies, specific dietary recommendations on fat intake (both in terms of quantity and quality) have been established by health organizations around the globe. Among the various food industry sectors, the margarine manufacturers have also responded to these guidelines and now offer improved formulations with a desirable balance of fat contents and fat types. The main aim of this article is to provide an overview on how these modern margarines can contribute towards reaching the dietary guidelines relating to fat intake. In particular, the dietary recommendations with respect to the specific fatty acid types are comprehensively detailed along with an emphasis on the role of modern margarines in providing balanced fat types (more polyunsaturated fats, less saturated fats and a near‐complete absence of trans fats) in the daily diet.     

Synergistic effects of oleogelators in tailoring the properties of oleogels: A review

Conventional solid fats play a crucial role as an ingredient in many processed foods. However, these fats contain a high amount of saturated fats and trans fats. Legislations and dietary recommendations related to these two types of fats set forth as a consequence of evidence showing their deleterious health impact have triggered the attempts to find alternate tailor-made lipids for these solid fats. Oleogels is considered as a novel alternative, which has reduced saturated fat and no trans fat content. In addition to mimicking the distinctive characteristics of solid fats, oleogels can be developed to contain a high amount of polyunsaturated fatty acids and used to deliver bioactives. Although there has been a dramatic rise in the interest in developing oleogels for food applications over the past decade, none of them has been commercially used in foods so far due to the deficiency in their crystal network structure, particularly in monocomponent gels. Very recently, there is a surge in the interest in using of combination of gelators due to the synergistic effects that aid in overcoming the drawbacks in monocomponent gels. However, currently, there is no comprehensive insight into synergism among oleogelators reported in recent studies. Therefore, a comprehensive intuition into the findings reported on synergism is crucial to fill this gap. The objective of this review is to give a comprehensive insight into synergism among gelators based on recent literature. This paper also identifies the future research propositions towards developing oleogels capable of exactly mimicking the properties of conventional solid fats to bridge the gap between laboratory research and the food industry.     

The effects of sources of supplemental fat on performance,egg quality,and fatty acid composition of egg yolk in laying hens

BACKGROUND: The objective of this study was to determine the effects of sources of supplemental fat on laying performance, egg quality, and fatty acid composition of egg yolk. RESULTS: Two hundreds Isa Brown layers were assigned randomly to be fed ad libitum a standard commercial layer feed (BD), basal diet plus 2% tallow (T), basal diet plus a mixture of 1% tallow and 1% flaxseed oil (MTFO), basal diet plus 2% sunflower oil (SO), or basal diet plus 2% flaxseed oil (FO), which were offered for 8 weeks. Each diet was given to five groups, each containing 10 hens. The feed efficiency and egg production were 2.78 and 53.51% for BD; 2.30 and 63.47% for T; 2.45 and 60.14% for MTFO; 2.29 and 64.30% for SO, and 2.62 and 61.18% for FO groups, respectively. Dietary fat supplementation affected the laying performance but had no significant effects on egg quality parameters. The fatty acid composition of egg yolk lipids were significantly affected by dietary fatty acid composition. The supplemental tallow increased palmitic fatty acid. The proportions of linoleic and arachidonic fatty acids in egg yolks for layers fed the SO diet were higher than in the BD group and those on diets containing other fats. Concentrations of oleic and omega‐3 fatty acids were the highest in layers fed the FO diet during the laying period. CONCLUSION: The results indicated that dietary animal and plant fats changed the fatty acid composition of egg yolk. Copyright © 2008 Society of Chemical Industry     

Palmitic Acid and Health: Introduction

Interest in the dietary role and metabolic effect of saturated fatty acids has been recently renewed on the basis of epidemiologic observations and economical approach to health and well-being. Saturated fats may favorably increase blood HDL-Cholesterol levels without significant changes of the total cholesterol/HDL-Cholesterol ratio. Also, the negative effect of saturated fat on cardiovascular diseases risk has recently been challenged. Palmitic acid, among all, may have special structural and functional roles in utero and in infancy, and indeed is it is being delivered in a unique form in human milk. Future research should include objective cost-benefit analyses when disentangling the role of saturated fats in dietary recommendations.