蒸煮对不同品质鸭肥肝营养特性及脂肪酸组成的影响

研究3种不同品质的鸭肥肝在蒸煮后常规养分、脂肪酸组成及脂质过氧化的变化。结果表明:1)熟化增加了鸭肥肝中C12:0、总脂和丙二醛(MDA)的含量,降低了水分、蛋白的含量,对鸭肥肝中糖原的含量无影响;2)鱼油组肥肝熟化后,其SFA、PUFA、n-6PUFA、n-3PUFA、EPA、DHA均显著高于大豆油组肥肝(P<0.05),极显著高于玉米组肥肝(P<0.01);3)玉米组肥肝熟化后SFA和MUFA显著降低(P<0.05),PUFA、n-6 PUFA、n-3 PUFA显著升高(P<0.05),大豆油组肥肝熟化对这几种脂肪酸的影响不大,而鱼油组肥肝熟化后这几种脂肪酸含量均升高,其中n-6PUFA达到显著水平(P<0.05);4)熟化具有降低3种肥肝中EPA和DHA的趋势,EPA降低幅度以玉米组肥肝最大,DHA降低幅度以大豆油组肥肝最大。以上结果提示,鱼油组肥肝的食用价值最高。     

野生与养殖鳡鱼肌肉的营养成分比较

对野生鳡鱼和养殖鳡鱼的营养品质进行研究。结果表明：这两种鱼肌肉中水分含量差异不显著(P＝0.07779＞0.05),而粗蛋白、粗灰分含量野生鳡鱼显著高于养殖鳡鱼(P＝0.00115、0.00415＜0.05),养殖鳡鱼粗脂肪含量显著高于野生鳡鱼(P＝0.000215＜0.05)。养殖鳡鱼的必需氨基酸指数为94.16,而野生鳡鱼则为66.03,其构成比例符合联合国粮农组织/世界卫生组织(FAO/WHO)的标准。野生和养殖鳡鱼肌肉脂肪酸中二十碳五烯酸(EPA)+二十二碳六烯酸(DHA)含量分别为4.25%和4.8%。综合所得结果,养殖鳡鱼氨基酸组成及结构、EPA+DHA含量均优于野生鳡鱼,但野生鳡鱼蛋白质含量与n-3/n-6多不饱和脂肪酸(PUFA)比例优于养殖鳡鱼。     

饲喂不同配比油脂饲料对肉鸡肉品质及肌肉中脂肪酸组成的影响

研究日粮中添加不同配比油脂对肉鸡肉品质、肌肉胆固醇含量及脂肪酸组成的影响。选取648只1日龄AA肉鸡,随机分成6组,CON为对照组(饲喂基础日粮),SO为正对照组(日粮中添加豆油),LO为负对照组(日粮中添加猪油),COP、COC、COV组分别在日粮中添加以棕榈油为主的配比油脂、以椰子油为主的配比油脂、多种植物油组成的配比油脂,实验期为42d。结果表明：COP组胸肌24h的滴水损失显著升高(P＜0.05);COC组腿肌烹饪损失显著降低(P＜0.05)。LO组胸肌不饱和脂肪酸/饱和脂肪酸得到提高(P＜0.05);SO、LO、COP、COC组n-3多不饱和脂肪酸含量均得到提高(P＜0.05);SO、COC组n-6多不饱和脂肪酸含量高于CON组(P＜0.05);除COV组外,各组n-6/n-3低于CON组(P＜0.05)。SO组胸肌胆固醇含量低于除LO组外的各组(P＜0.05)。结论：配比油脂组提高了肉鸡肌肉中多不饱和脂肪酸(PUFA)含量,对肉鸡肉品质没有产生不良的影响,豆油组改善了胸肌中脂肪酸比例并降低胆固醇含量,以椰子油为主的配比油脂次之。     

多不饱和脂肪酸对大鼠肠道菌群及脂肪代谢相关基因的影响

目的：研究多不饱和脂肪酸（polyunsaturated fat acids,PUFA）饮食对大鼠肠道菌群及相关脂肪因子的影响,探讨其作用机理。方法：将30 只5 周龄健康大鼠分为正常对照组、n-6 PUFA组和n-3 PUFA组,自由摄食饮水8 周,每周记录大鼠体质量,实验结束时取大鼠盲肠粪便和肝脏,用实时荧光定量聚合酶链式反应检测双歧杆菌（Bifidobacterium,Bif）、乳酸杆菌（Lactobacillus,Lac）、肠道细菌Akkermansia muciniphila（Akk）和脂肪因子脂肪酸合成酶（fatty acid synthetase,FAS）、禁食诱导脂肪因子（fasting-induced adipose factor,FIAF）的水平;并将大鼠盲肠石蜡包埋、切片、苏木精-伊红染色测量其黏膜厚度。结果：n-3 PUFA组与正常对照组相比,肥胖程度和FAS水平明显降低（P＜0.05）,Bif、Lac、Akk和FIAF水平明显升高（P＜0.05）,肠道黏膜厚度明显增加;n-6 PUFA组大鼠的各项指标和正常对照组相比均无统计学差异。结论：n-3 PUFA饮食与n-6 PUFA饮食相比,可改变肠道菌群,抑制肥胖的发生和发展。     

青海牦牛肉与秦川牛肉氨基酸和脂肪酸的比较研究

通过青海牦牛肉与秦川牛肉的氨基酸和脂肪酸的比较研究,分析青海牦牛肉品质的特性及其潜在优势.选取秦川牛肉,青南、大通和环青海湖地区的成年牦牛肉以及大通犊牦牛肉进行氨基酸和脂肪酸的相关研究.结果表明:牦牛肉各组的蛋白质含量高于秦川牛肉,但差异不显著(P＞0.05);脂肪含量都低于秦川牛肉,差异极显著(P＜0.01).青南地区成年牦牛肉的必需氨基酸/非必需氨基酸(EAA/NAA)值、必需氨基酸/氨基酸总量(EAA/TAA)值、18∶2cis-12,15、α-亚麻酸、20∶0、多不饱和脂肪酸(PUFA)、必需脂肪酸(EFA)、多不饱和脂肪酸/脂肪酸总量(P∶S)值和n-3多不饱和脂肪酸都显著高于秦川牛肉(P＜0.05或P＜0.01);16∶0、二十碳五烯酸(EPA)和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).大通成年牦牛肉的赖氨酸、组氨酸和15∶0都显著高于秦川牛肉(P＜0.05或P＜0.01);月桂酸、亚油酸、PUFA、EFA、n-6多不饱和脂肪酸和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).环湖地区成年牦牛肉的脯氨酸、15∶0、16∶1cis-9、17∶0和18∶2cis-12,15都显著高于秦川牛肉(P＜0.05或P＜0.01);月桂酸和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).大通犊牦牛肉的色氨酸、肉豆蔻酸、17∶1cis-9、18∶1cis-11、亚油酸、α-亚麻酸、20∶3cis-5,8,11、20∶3cis-7,10,13、花生四烯酸(AA)、EPA、PUFA、EFA、P∶S值、n-3多不饱和脂肪酸和n-6多不饱和脂肪酸都显著高于秦川牛肉(P＜0.05或P＜0.01);脯氨酸、14∶1cis-9、棕榈酸、17∶0、油酸、SFA、MUFA和n-6/n-3值都显著低于秦川牛肉(P＜0.05或P＜0.01).结论:青海成年牦牛肉的蛋白质和必需氨基酸含量稍高于秦川牛肉,组成与秦川牛相近,但犊牦牛肉的氨基酸含量稍差一些.牦牛肉的n-6/n-3多不饱和脂肪酸比秦川牛肉合理,都在4.0左右,其中犊牦牛肉的P∶S值为1.15,说明牦牛肉的脂肪酸品质优,尤其是犊牦牛肉.     

南极磷虾油、鱼油与花生四烯酸油对骨质疏松症小鼠脂质代谢的影响

目的：比较南极磷虾油、鱼油和花生四烯酸油对去卵巢骨质疏松小鼠脂质代谢的影响。方法：对8 周龄健康雌性C57BL/6J小鼠部分进行双侧去卵巢手术,建立绝经后骨质疏松症模型;部分不进行去卵巢手术,仅进行开腹腔与缝合的假手术,作为假手术组（生理盐水）。将造模成功的小鼠分为模型对照组（生理盐水）、南极磷虾油组（150 mg/kg mb）、鱼油组（80 mg/kg mb）和花生四烯酸油组（140 mg/kg mb）。连续灌胃12 周后取材,测定骨密度,血清和肝脏中的总胆固醇、甘油三酯水平,肝脏中脂质合成相关基因表达水平等相关指标。结果：两种n-3多不饱和脂肪酸（polyunsaturated fatty acids,PUFA）油脂南极磷虾油和鱼油能极显著降低骨质疏松小鼠体脂比（P＜0.01）,改善血脂及肝脏脂质水平,显著或极显著下调肝脏中脂质合成关键基因SREBP-1c、FAS、ACC、SCD1的mRNA表达（P＜0.05、P＜0.01）;而n-6 PUFA油脂花生四烯酸油会升高血脂水平并上调肝脏中脂质合成关键基因的表达。结论：两种n-3 PUFA均能够显著改善骨质疏松小鼠脂代谢紊乱,且南极磷虾油效果更好;而n-6 PUFA花生四烯酸油则加剧脂代谢紊乱。     

α-亚麻酸体内转化为二十碳五烯酸和二十二碳六烯酸的研究进展

水产品是二十碳五烯酸(EPA)和二十二碳六烯酸(DHA)等n-3长链多不饱和脂肪酸(n-3LCPUFA)的主要膳食来源。我国广大内陆地区居民膳食中水产品消费量很低,EPA和DHA的摄入量远低于推荐量。α-亚麻酸(ALA)是我国居民膳食中最主要的n-3多不饱和脂肪酸(n-3PUFA),其在体内可以转化为n-3 LCPUFA。近来的研究表明,ALA转化能力受ALA摄入状况及人群生理差异影响,其中新生儿的内源转化效率较低,而育龄期妇女和鱼类低消费人群的转化效率较高,提示膳食ALA对改善这些人群的脂肪酸营养状况有着重要的意义。通过对相关方面的研究进行综述,以期更加客观、全面地认识α-亚麻酸的作用。     

日粮中添加亚麻籽和双低菜籽混合原料提高鸡蛋中N-3PUFA含量的研究

选取健康25周龄农大三号粉壳蛋鸡180只,按体重一致的原则随机分成5组,每组6个重复,每个重复6只鸡.第1组为对照组,饲喂玉米-豆粕型基础日粮,其他几个处理组分别在基础日粮中添加10%亚麻籽+1%鱼油(2组),10%亚麻籽+5%去皮双低菜籽(3组),5%亚麻籽+10%未去皮双低菜籽(4组),5%亚麻籽+10%去皮双低菜籽(5组),旨在研究每组中的两种不同原料的配比对鸡蛋中n-3PUFA含量和蛋鸡生产性能的影响.饲料和鸡蛋中脂肪酸采用气相色谱分析.试验结果表明:10%亚麻籽+1%鱼油组n-3PUFA含量显著高于对照组和其他处理组(P<0.01),10%亚麻籽+5%去皮双低菜籽n-3PUFA富集量低于鱼油组(P<0.01),但显著高于对照组和其他两组(P<0.01);10%亚麻籽+1%鱼油组鸡蛋中DHA含量明显高于其他几组(P<0.01),其他3个处理组间无显著性差异(P>0.01);各处理组中添加的两种混合n-3PUFA原料对蛋鸡生产性能无显著性影响(P>0.05);感官评分结果表明:10%亚麻籽+1%鱼油可使鸡蛋产生鱼腥味,降低鸡蛋的感官评分.综合考虑蛋中n-3PUFA富集量和人们对鸡蛋的可接受性,本试验认为日粮中添加10%亚麻籽+5%去皮双低菜籽可用于高富集量n-3PUFA鸡蛋的生产.     

饲喂鱼油对小鼠干眼症的治疗及缓解作用

研究饲喂鱼油对小鼠干眼症的治疗及缓解作用。采用苯扎氯氨诱导小鼠发生干眼症,并将其随机分为对照组(棕榈油替代鱼油)及鱼油饲喂组,饲喂14 d前后分别检测两组小鼠的泪液分泌量及泪膜破裂时间;14 d后处死小鼠,取眼周腺体,气相色谱法检测其DHA含量。结果表明:与饲喂前比较,鱼油饲喂组泪液分泌量增加、泪膜破裂时间明显延长(P0.05),对照组各指标变化不明显(P0.05);饲喂14 d后组间比较,鱼油饲喂组泪液分泌量增加、泪膜破裂时间明显延长(P0.05);饲喂14 d后,鱼油饲喂组眼周腺体中DHA含量极显著高于对照组(P0.01);高DHA膳食可减轻苯扎氯铵诱导的干眼症小鼠的干眼症状,可能与眼部腺体中DHA的供应有关。     

膳食补充n-3多不饱和脂肪酸保护大鼠衰老皮肤胶原的作用及机制研究

目的:探索膳食补充n-3多不饱和脂肪酸(n-3 PUFAs)对大鼠自然老化皮肤真皮胶原的保护作用及机制。方法:选取9月龄大鼠为年轻组,22月龄大鼠作为老化n-3 PUFAs组(膳食补充n-3 PUFAs)及老化对照组(膳食中脂质成分模拟日常饮食中成分作为对照)。通过HE染色、Masson染色及Weigert染色观察年轻组大鼠、老化n-3 PUFAs组和老化对照组大鼠真皮结构变化,ELISA检测Ⅰ、Ⅲ型胶原表达量,RT-qPCR检测Ⅰ、Ⅲ、Ⅳ、Ⅴ型胶原和MMP1、MMP3、MMP9、MMP10、MMP13的mRNA表达量。结果:老化大鼠表皮较年轻大鼠变平变薄,真皮胶原排列紊乱,Ⅰ、Ⅲ型胶原含量显著减少(P<0.05),Ⅰ、Ⅲ、Ⅳ、Ⅴ型胶原mRNA表达量显著下调(P<0.05)。老化n-3 PUFAs组中Ⅰ、Ⅲ型胶原含量及mRNA相对表达量均较老化对照组显著提高(P<0.05)。老化大鼠皮肤中MMP1、MMP9、MMP10、MMP13 mRNA相对表达量均较年轻大鼠显著增多(P<0.05),老化n-3 PUFAs组中MMP10、MMP13 mRNA相对表达量较老化对照组显著降低(P<0.05)。结论:膳食补充n-3 PUFAs可促进老化大鼠皮肤Ⅰ、Ⅲ型胶原合成,减少MMP10、MMP13的表达,增加皮肤中Ⅰ、Ⅲ型胶原含量,延缓皮肤自然老化进程。     

Magnesium and exercise

Magnesium is an essential element that regulates membrane stability and neuromuscular, cardiovascular, immune, and hormonal functions and is a critical cofactor in many metabolic reactions. The Dietary Reference Intake for magnesium for adults is 310 to 420 mg/day. However, the intake of magnesium in humans is often suboptimal. Magnesium deficiency may lead to changes in gastrointestinal, cardiovascular, and neuromuscular function. Physical exercise may deplete magnesium, which, together with a marginal dietary magnesium intake, may impair energy metabolism efficiency and the capacity for physical work. Magnesium assessment has been a challenge because of the absence of an accurate and convenient assessment method. Recently, magnesium has been touted as an agent for increasing athletic performance. This article reviews the various studies that have been conducted to investigate the relationship of magnesium and exercise.     

Muscle growth and exercise

This paper first reviews muscle growth and then considers the influence of exercise in growth. Knowledge about how muscle cells grow and some factors that may influence the growth pattern are discussed first since these effects must be considered before the influence of exercise becomes clear. Growth of muscle can occur in three ways: (1) by an increase in muscle cell numbers, (2) by an increase in muscle fiber diameter, and (3) by an increase in fiber length. All three of these mechanisms are involved in muscle growth. However, growth in cell numbers is limited to the prenatal and immediately postnatal period, with the animals and man being born with or soon reaching their full complement of muscle cells. Thus, growth occurs by either hypertrophy of the existing muscle fibers by adding additional myofibrils to increase the muscle mass or by adding new sarcomeres to the ends of the existing muscle fibers to increase their length. Both of these mechanisms occur during the growth process. Growth in the girth of the muscle fibers appears to take place by splitting of the myofibrils. This may be stimulated by development of stress creating an unequal pressure with splitting at the Z-band and development of additional SR and T-tubule systems. This adds to the diameter or girth of myofibers without any hyperplasia. The growth in length occurs at either end of the fibers and results in addition of new sarcomeres. In both cases, new myofibrillar protein must be synthesized and deposited in the muscle cells. It is suggested that adaptation by adding or removing sarcomeres is physiologically determined by the degree of force a muscle can generate that is in turn dependent on the degree of overlap of the thick and thin filaments. Thus, the amount of tension would control the number of in-series sarcomeres in a single muscle fiber. Nutrition is also known to play an important role in muscle and was discussed from the standpoint of the effects of nutritional adequacy and restriction. Although a nutritionally balanced and calorically adequate diet is required to achieve optimum muscle growth, it may be less efficient in terms of protein deposition than a moderately restricted diet. Muscle and bone deposition, however, can be limited on severely restricting the dietary intake. Although fat deposition is the first tissue to suffer on a severely restricted diet, muscle and bone follow next with the nervous system, brain and eyes being the last systems to be affected.(ABSTRACT TRUNCATED AT 400 WORDS)     

谷氨酰胺对运动能力影响的研究进展

谷氨酰胺是人或哺乳动物体内含量最丰富的一种游离的条件必需氨基酸, 是机体内众多代谢活动的能量来源, 对机体各器官功能的正常发挥起着重要的作用。但是在应激状态下, 谷氨酰胺的供求平衡会被打破。谷氨酰胺因其独特且复杂的生理特性成为营养学、生理学、生物化学、运动医学等多领域的研究热点。随着国际竞技体育的蓬勃发展, 功能性运动补充剂不断被开发, 在此期间谷氨酰胺在运动能力提升方面的巨大潜力被发掘, 经过研究发现谷氨酰胺能够有效提高机体运动能力并延缓疲劳。本文对过度运动与谷氨酰胺之间的关系及谷氨酰胺的生理功效进行综述, 并对谷氨酰胺未来的研究方向进行展望。     

器械有氧练习的对与错

一、划船机 动作——不协调，手与膝互相碰撞。 纠正方法：按照跳舞的节奏来做划船练习。按1-2-3、3—2—1的节奏练习。其中，“1”是蹬腿，“2”是挺身后仰，“3”是拉臂至胸前下端。回程也按3—2—1的顺序，放松手臂，身体前倾，手过膝后屈膝还原。整个动作应该流畅自然，富有节奏。     

跑步者如何锻炼肌肉

跑步者如果想要跑得更快、更理想、更强壮，需要采用专门的方法来锻炼自己的核心肌肉。20多年前，很少发现有顶级的跑步者把精力花在锻炼他们的腹部肌肉上。而现在，这已经成了必不可少的音盼。     

Chromium, exercise, and body composition

Chromium is an essential trace element involved in the metabolism of carbohydrates, lipids, and proteins mainly by increasing the efficiency of insulin. Chromium deficiency affects the maintenance of normal glucose tolerance and healthy lipid profiles. The Estimated Safe and Adequate Daily Dietary Intake for chromium is 50 to 200 microg/d for adults. However, the dietary intake of chromium in humans is often suboptimal. Chromium assessment has proven to be a challenge due to the low amounts of chromium present in biological materials and the absence of a reliable indicator of chromium status. Recently, chromium has been touted as an agent for increasing lean body mass and decreasing percent body fat. This article reviews the various studies that have been conducted to investigate the relationship of chromium with exercise and body composition.     

有氧运动中的“美体机”——舒华SH-821运动冲浪器

夏日，什么方法瘦身最酷，美国MM们会告诉你：冲浪。冲浪本身是一种潇洒优美的水上运动。冲浪爱好者可以立于冲浪板上或直接踏水，靠奔向岸边的海浪托起而浮于水面。由于夏日来临，很多肥胖者难耐高温而纷纷跳进海中，借冲浪来消除腰部、腿部和胳膊赘肉。其中美国的夏威夷海常常成为人们冲浪的首选。     

Zinc, exercise, and thyroid hormone function.

During the last 3 decades, remarkable advances have taken place in the field of zinc metabolism. Thirty years ago, only three enzymes that required zinc for their activities were identified; today more than 200 such enzymes have been classified. Zinc plays a vital role in human nutrition and biochemical function. Prior to 1963, zinc deficiency in humans was unknown. Today, it is recognized that a nutritional deficiency of zinc is common throughout the world, including the U.S.A marginal deficiency of zinc appears to be prevalent in many segments of populations in developed countries, and more severe deficiencies are widespread in many parts of the world. Therefore, it is important that proper steps to correct zinc deficiency are taken. However, the assessment of zinc nutriture has always proven to be a difficult problem because no reliable measure of zinc status currently exists. More recently, it has been recognized that zinc may play an important role in thyroid hormone metabolism, although the exact mechanism by which zinc affects thyroid hormone function is far from clear. In addition, exercise has been shown to alter zinc status. This review will focus on the relationship among zinc status, exercise, and thyroid hormone function.     

饮酒适度而又爱好运动的人更长寿

最近,在丹麦进行的一项长期研究发现,爱好运动而饮酒又有节制的人会更长寿.2008年1月9日,发表在<欧洲心脏杂志>(European Heart Journal)上的这项研究声称,适量饮酒和适度锻炼都与长寿有关,而更重要的是,当这两种行为结合起来时益处会更多.     

Cigarette smoking weakens exercise habits in healthy men.

To investigate the longitudinal impact of smoking cessation and relapse on the exercise habits of apparently healthy Japanese men, 750 subjects presenting for a checkup at a metropolitan health center were surveyed annually for 7 years. Exercise was dichotomously classified as none or any. Subjects were grouped in two categories: 98 smokers who ceased smoking during the second year of the study, matched with 196 continuing smokers and 196 men who had never smoked; and 52 relapsed smokers (including 2 new smokers) who did not smoke at baseline or at Year 1 but smoked from Year 2 to final follow-up, matched with 104 continuing smokers and 104 never-smokers. Based on self-reported responses to questionnaires, exercise was consistently less prevalent among smokers who did not quit than among never-smokers throughout the study. Habitual exercise in subjects who had quit smoking increased during the follow-up (any exercise: 42.9% at baseline increased to 51% at final follow-up, p for longitudinal trend = .115). Habitual exercise in matched never-smokers did not change during the study and decreased significantly among persistent smokers (p = .025). Habitual exercise in relapsed smokers decreased during the follow-up (any exercise: 50.0% at baseline declined to 32.7% at final follow-up, p = .007), but habitual exercise in matched persistent smokers and never-smokers did not change. We conclude that smoking and sedentary lifestyle coexist continuously, that smoking cessation is associated with increased habitual exercise among healthy men, and that relapse is associated with reduced habitual exercise, suggesting that cigarette smoking weakens exercise habits.