Ovomucin content and composition in chicken eggs with different interior quality

Egg albumen ovomucin distribution and composition were studied in fresh eggs with relatively low or high internal quality as indicated by Haugh unit (HU) values. Egg HU had been altered as a result of genetic selection (mean all eggs: 87 vs 73 HU) or by feeding vanadium (V) to hens (mean all eggs: 91 vs 80 HU). In both altered HU conditions, eggs with low HU values yielded significantly less water-insoluble ovomucin from the thick albumen than eggs with high HU values, whereas the yield of ovomucin from thin albumen did not differ. The amount of ovomucin differed between eggs with high or low HU values as a result of feeding V, but the composition of ovomucin from the thick albumen was not affected. This was confirmed by SDS-PAGE gels, carbohydrate contents, and amino acid contents. When HU values were different as a result of genetics, ovomucin was affected differently. The total amount of ovomucin isolated from the thick albumen of the eggs with high HU was much higher than the amount isolated from the low HU thick albumen. The composition of the ovomucin was also different. SDS-PAGE gels showed a greater proportion of the highly glycosylated β-subunit in the ovomucin from the low HU eggs. Carbohydrate analyses showed higher concentrations of sialic acids, hexoses and hexosamines in the ovomucin from the low HU eggs. The only difference between the ovomucins in the amino acid content was that isoleucine was slightly higher in the high HU ovomucin. © 1999 Society of Chemical Industry     

Systematic analysis of yeast strains with possible defects in lipid metabolism

Lipids are essential components of all living cells because they are obligate components of biological membranes, and serve as energy reserves and second messengers. Many but not all genes encoding enzymes involved in fatty acid, phospholipid, sterol or sphingolipid biosynthesis of the yeast Saccharomyces cerevisiae have been cloned and gene products have been functionally characterized. Less information is available about genes and gene products governing the transport of lipids between organelles and within membranes or the turnover and degradation of complex lipids. To obtain more insight into lipid metabolism, regulation of lipid biosynthesis and the role of lipids in organellar membranes, a group of five European laboratories established methods suitable to screen for novel genes of the yeast Saccharomyces cerevisiae involved in these processes. These investigations were performed within EUROFAN (European Function Analysis Network), a European initiative to identify the functions of unassigned open reading frames that had been detected during the Yeast Genome Sequencing Project. First, the methods required for the complete lipid analysis of yeast cells based on chromatographic techniques were established and standardized. The reliability of these methods was demonstrated using tester strains with established defects in lipid metabolism. During these investigations it was demonstrated that different wild‐type strains, among them FY1679, CEN.PK2‐1C and W303, exhibit marked differences in lipid content and lipid composition. Second, several candidate genes which were assumed to encode proteins involved in lipid metabolism were selected, based on their homology to genes of known function. Finally, lipid composition of mutant strains deleted of the respective open reading frames was determined. For some genes we found evidence suggesting a possible role in lipid metabolism. Copyright © 1999 John Wiley & Sons, Ltd.     

不同品种禽蛋中胆碱含量测定与分析研究

目的建立酶比色法测定禽蛋中胆碱含量的分析方法。方法在GB 5413.20-2013《食品安全国家标准婴幼儿食品和乳品中胆碱的测定》方法的基础上对检验条件(称样量、水解时间)迚行优化。幵比较分析不同品种禽蛋全蛋和蛋黄中胆碱含量水平和差异。结果称样量和水解时间优化结果为:全蛋和蛋黄称样量分别为1.0～2.0 g、0.5～1.0 g,水解时间为4 h。胆碱氢氧化物在50～250μg/mL浓度范围内线性良好(r=1),样品精密度相对标准偏差2.17%;样品加标回收率为94.0%～101.2%,相对标准偏差为1.86%～5.13%。蛋黄与全蛋中胆碱含量呈显著正相关(r=0.499, P0.01)。鸡蛋、鸭蛋、鹅蛋、鹌鹑蛋中胆碱含量(蛋黄)有显著差异(P0.05),鹅蛋、鹌鹑蛋中含量高,其次为鸭蛋、鸡蛋,其蛋黄中胆碱含量均值分别为1222.5、1277.9、1345.1、1340.8 mg/100 g。土鸡蛋、乌鸡蛋中胆碱含量(蛋黄、全蛋)显著高于普通鸡蛋(P0.05)。乌鸡蛋与土鸡蛋蛋黄、全蛋胆碱含量均无显著差异(P0.05)。咸鸭蛋中胆碱含量明显高于生鸭蛋,蛋黄中含量均值分别为1181.8、1406.0mg/100g,且差异具有统计学意义(P0.001)。结论本研究建立了禽蛋类胆碱提取测定方法-酶比色法,幵探讨了不同品种禽蛋营养价值,为消费者合理选择不同品种禽蛋提供参考。     

Proximate Composition and Seed Lipid Components of Sorghum Cultivars from Argentina

Seeds of 11 sorghum cultivars ( Sorghum bicolor ) from Argentina were analysed for proximate composition, fatty acids and sterols. Oil, protein, carbohydrate and ash contents varied between 41 and 66 g kg⁻¹, 111 and 156 g kg⁻¹, 670 and 730 g kg⁻¹ and 13·8 and 20·6 g kg⁻¹ of dry matter, respectively. Fatty acid profiles revealed that the major acids were palmitic (15·1–24·8%), oleic (29·9–41·8%) and linoleic (35·9–51·3%). Unsaponifiable matter was examined for sterols. Sitosterol was the prominent component in all cultivars (43·8–57·9%), followed by campesterol (18·7–29·1%) and stigmasterol (12·4–20·5%).     

不同产地油菜籽氨基酸组成比较研究

目的研究不同产地油菜籽中氨基酸水平的差异性。方法参照GB 5009.124-2016,用氨基酸自动分析仪检测长江上中下游鄂、苏、川、贵4省油菜籽中氨基酸。结果四川省油菜籽总氨基酸含量最高,为(24.47±0.22)mg/100 mg,同时各产地油菜籽必需氨基酸含量占氨基酸总量均在33%以上,其中湖北产地最高,为34.30%。通过t检验得到两两产地不同氨基酸具有显著性差异,其中半胱氨酸(cysteine,Cys)是差异性氨基酸中最显著的氨基酸。结论不同产地油菜籽中蛋白质的氨基酸含量和组成有较大差异,在加工过程中应选择适宜产地的油菜籽,从而提高油菜籽的利用率。     

摄食不同来源磷脂对大鼠脂质代谢及脑内磷脂脂肪酸组成的影响

研究了摄食不同来源磷脂对大鼠脂质代谢及其脑内磷脂脂肪酸组成的影响。雄性SD大鼠按体重随机分为大豆油对照组(添加9%)、牛乳磷脂组(添加5%)、大豆磷脂组(添加5%)、蛋黄磷脂组(添加5%),喂食3周。检测了血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)、游离脂肪酸(FFA)及肝脏TC、TG、磷脂(PL)的含量,并用气相色谱法测定了脑内磷脂脂肪酸的组成变化。结果显示:与大豆油对照组相比,3种磷脂均不同程度提高了大鼠体重、脏器指数,蛋黄磷脂效果显著;3种磷脂不同程度降低了血清TC、TG和FFA含量,牛乳磷脂降低血清FFA显著,大豆磷脂降低血清TC、TG显著,蛋黄磷脂降低FFA显著,大豆磷脂显著提升了血清HDL-C含量;3种磷脂不同程度降低了肝脏TC、TG、PL含量,牛乳磷脂与大豆磷脂降低肝脏TG、TC显著,而蛋黄磷脂降低肝脏TG显著;3种磷脂对脑内磷脂脂肪酸组成的影响各不相同,牛乳磷脂显著提高了脑内磷脂饱和脂肪酸含量,而大豆磷脂和蛋黄磷脂提高了DHA等多不饱和脂肪酸含量。研究表明,3种磷脂均有降血脂、肝脂作用,以大豆磷脂作用尤为明显,大豆磷脂和蛋黄磷脂的益智作用可能优于牛乳磷脂。     

不同地区油菜籽脂肪酸组成及含量

采用气相色谱法对不同地区多个品种油菜籽的脂肪酸组成及含量进行分析。结果表明：不同地区各油菜籽品种所含脂肪酸组成基本相同,均含有17种脂肪酸,脂肪酸种类比较丰富;油菜籽中含量较多的脂肪酸有油酸、芥酸、亚油酸、亚麻酸和花生一烯酸,各品种油菜籽间油酸、芥酸和花生一烯酸含量差异较大,亚油酸和亚麻酸含量差异较小;杂交、丰油10号和杂双5号油菜籽可作为丰富的油酸、亚油酸来源,搏优6号和皖油13油菜籽可作为丰富的花生一烯酸来源,南阳红、秦优9号、花菜子和四月红油菜籽可作为丰富的芥酸来源,杂双5号油菜籽可作为低芥酸菜籽油的原料来源;种植土壤对杂交油菜籽脂肪酸含量影响较大,而丰油10号油菜籽脂肪酸含量不受种植土壤的影响,无论是杂交油菜籽还是丰油10号油菜籽,在相同种植土壤条件下,即使来自不同地区,同品种油菜籽脂肪酸含量均无明显差异。     

Biochemistry,cell biology and molecular biology of lipids of Saccharomyces cerevisiae

The yeast Saccharomyces cerevisiae is a powerful experimental system to study biochemical, cell biological and molecular biological aspects of lipid synthesis. Most but not all genes encoding enzymes involved in fatty acid, phospholipid, sterol or sphingolipid biosynthesis of this unicellular eukaryote have been cloned, and many gene products have been functionally characterized. Less information is available about genes and gene products governing the transport of lipids between organelles and within membranes, turnover and degradation of complex lipids, regulation of lipid biosynthesis, and linkage of lipid metabolism to other cellular processes. Here we summarize current knowledge about lipid biosynthetic pathways in S. cerevisiae and describe the characteristic features of the gene products involved. We focus on recent discoveries in these fields and address questions on the regulation of lipid synthesis, subcellular localization of lipid biosynthetic steps, cross-talk between organelles during lipid synthesis and subcellular distribution of lipids. Finally, we discuss distinct functions of certain key lipids and their possible roles in cellular processes. © 1998 John Wiley & Sons, Ltd.     

Lipid composition of Bulgarian chokeberry,black currant and rose hip seed oils

The lipid composition of chokeberry, black currant and rose hip seeds was investigated. The seeds contain 19.3 g kg⁻¹, 22.0 g kg⁻¹ and 8.2 g kg⁻¹ glyceride oil respectively. The content of phospholipids, mainly phosphatidylcholine, phosphatidylinositol and phosphatidylethanolamine, was 2.8 g kg⁻¹, 1.3 g kg⁻¹ and 1.4 g kg⁻¹, respectively. The total amounts of sterols were 1.2 g kg⁻¹, 1.4 g kg⁻¹ and 0.4 g kg⁻¹. The main component was β-sitosterol, followed by campesterol and Δ⁵ -avenasterol. In the tocopherol fraction (55.5 mg kg⁻¹ in chokeberry oil, 249.6 mg kg⁻¹ in black currant oil and 89.4 mg kg⁻¹ in rose hip oil), α-tocopherol predominated in chokeberry oil (70.6 mg kg⁻¹). γ-Tocopherol was the main component in black currant oil (55.4 mg kg⁻¹) and rose hip oil (71.0 mg kg⁻¹). The fatty acid composition of triacylglycerols, individual phospholipids and sterol esters was also identified. In the phospholipids and sterol esters, the more saturated fatty acids, mainly palmitic, stearic, and long chain fatty acids predominated. © 1999 Society of Chemical Industry     

基于靶向代谢组学法鉴别真伪海鸭蛋

目的建立基于气相色谱-质谱(gas chromatography-mass spectrometry, GC-MS)的靶向代谢组学方法进行海鸭蛋真伪鉴别。方法采用气相色谱-质谱法,对海鸭蛋和笼养鸭蛋中的脂肪酸种类和含量进行分析检测。进一步应用化学计量学进行海鸭蛋与笼养鸭蛋的差异分析,筛选出可用于海鸭蛋真伪鉴别的标志物。结果海鸭蛋中的omega-3脂肪酸(Ω-3)在总脂肪酸中的占比高于笼养鸭蛋,差异有统计学意义(t=23.58,P0.05)。进一步通过主成分分析区分了海鸭蛋和笼养鸭蛋,通过正交偏最小二乘判别分析筛选出对海鸭蛋和笼养鸭蛋分类贡献最大的二十碳五烯酸(eicosapentaenoic acid,EPA)和二十二碳六烯酸(docosahexaenoic acid, DHA),EPA仅在海鸭蛋中检出,DHA在海鸭蛋中的含量高于笼养鸭蛋。结论 EPA和DHA可以作为标志物进行海鸭蛋的真伪鉴别。     

不同母乳营养成分的比较

比较了不同时期母乳成分、早产儿与足月儿母乳成分、城区与郊区母乳成分以及母乳与牛乳成分的差异。结果表明。母乳成分基本上能满足婴儿的需求，然而随着婴儿的生长发育其某些营养成分不能完全满足其营养的需要（如有些矿物质、维生素等），而且母乳的营养成分受到乳母膳食营养、饮食习惯、民族、文化和地域等因素的影响，乳母可通过膳食的调整来弥补这些营养素的缺陷。牛乳中营养素与母乳有很大不同，可通过调整牛奶中营养素使之满足婴儿的营养需求、因此，研究不同国家和民族母乳的营养成分对生产母乳化的配方奶粉具有重要意义。     

The value of different fat supplements as sources of digestible energy for lactating dairy cows

The effects of fat supplements that differed in fatty acid composition (chain length and degree of saturation) and chemical form (free fatty acids, Ca salts of fatty acids, and triacylglyceride) on digestible energy (DE) concentration of the diet and DE intake by lactating cows were measured. Holstein cows were fed a control diet [2.9% of dry matter (DM) as long-chain fatty acids] or 1 of 3 diets with 3% added fatty acids (that mainly replaced starch). The 3 fat supplements were (1) mostly saturated (C18:0) free fatty acids (SFA), (2) Ca-salts of fatty acids (CaFA), and (3) triacylglyceride high in C16:0 fatty acids (TAG). Cows fed CaFA (22.8 kg/d) consumed less DM than cows fed the control (23.6 kg/d) and TAG (23.8 kg/d) diets but similar to cows fed SFA (23.2 kg/d). Cows fed fat produced more fat-corrected milk than cows fed the control diet (38.2 vs. 41.1 kg/d), mostly because of increased milk fat percentage. No differences in yields of milk or milk components were observed among the fat-supplemented diets. Digestibility of DM, energy, carbohydrate fractions, and protein did not differ between diets. Digestibility of long-chain fatty acids was greatest for the CaFA diet (76.3%), intermediate for the control and SFA diets (70.3%), and least for the TAG diet (63.3%). Fat-supplemented diets had more DE (2.93 Mcal/kg) than the control diet (2.83 Mcal/kg), and DE intake by cows fed supplemented diets was 1.6 Mcal/d greater than by cows fed the control, but no differences were observed among the supplements. Because the inclusion rate of supplemental fats is typically low, large differences in fatty acid digestibility may not translate into altered DE intake because of small differences in DM intake or digestibility of other nutrients.     

不同畜禽肌肉脂肪酸组成的对比分析

采用GC-MS测定猪、牛、鸡、兔后腿肌脂肪酸组成的相对百分含量和实际当量,测定结果表明四者的主要脂肪酸组成有17种,其中棕榈酸（16∶0）、硬脂酸（18∶0）、油酸（18∶1n-9）、亚油酸（18∶2n-6）和花生四烯酸（20∶4n-3）的总含量占肌肉总脂肪酸含量分别为84.35%、79.71%、81.78%、81.19%。n-6/n-3比率猪肉最高,鸡肉、兔肉次之,牛肉最低。就综合营养价值而言,兔肉最高,牛肉、鸡肉次之,猪肉最低。      

Seed compositional studies of some species of Papilionoideae (Leguminosae) native to Argentina

Seeds of 17 wild leguminous species belonging to the Papilionoideae subfamily were analysed for their proximate, fatty acid and sterol compositions. Centrosema virginianum, Tipuana tipu, Adesmia volckmanni and some species of Desmodium contained high amounts (>300 g kg^?1) of protein. Geoffroea decorticans and Clitoria cordobensis were noteworthy for their high oil content (>350 g kg^?1). The seed lipids had a high proportion of unsaturated (oleic and linoleic mainly) fatty acids. Linolenic acid had the highest value in Adesmia volckmanni (25.4% of total fatty acids). β‐Sitosterol was the major component of the sterol fraction. Chemical analyses indicated that all species studied are suitable sources of animal feed. © 2002 Society of Chemical Industry     

抗生素在鸡蛋及鸡体组织中的代谢研究

目的 探究蛋鸡养殖业中广泛使用且在市场鸡蛋中检出频率较高的3种抗生素：氟苯尼考(florfenicol, FF)、恩诺沙星(enrofloxacin, ENR)、多西环素(doxycycline, DOX)在鸡蛋及鸡体组织中的代谢情况。方法 试验选取健康的103日龄育成鸡和300日龄产蛋鸡各105只,均分成7组,分别为FF低、FF高、ENR低、ENR高、DOX低、DOX高以及对照组。以肌肉注射的方式连续给药5 d,“低”代表说明书正常用量,“高”代表正常用量的一倍,对鸡只接受抗生素后一段时间内所产鸡蛋及鸡体组织中药物残留情况进行检测分析。结果 103日龄育成鸡使用抗生素后,至鸡只130日龄时所产鸡蛋中能检测到氟苯尼考残留,150日龄时所产鸡蛋中能检测到恩诺沙星和多西环素残留,3种抗生素还造成蛋鸡肝脏组织表面不同程度的出血和坏死;300日龄产蛋鸡注射抗生素后,氟苯尼考在蛋清、蛋黄中消除的时间分别为10 d、12 d。恩诺沙星在蛋清、蛋黄中消除的时间均为9 d。多西环素在蛋清、蛋黄中消除的时间均为25 d。结论 蛋鸡育成后期使用抗生素会对初产鸡蛋及鸡的肝脏组织造成一定影响,针对我国市场动物源性食品中频繁检出抗生素等问题,建议关注蛋鸡后备期抗生素的使用,不断强化市场监督机制和准入门槛,保障鸡蛋安全,维护人体健康。     

不同规格秋刀鱼肌肉的营养成分分析与品质评价

摘 要: 目的 对比分析不同规格秋刀鱼肌肉的营养价值。方法 参照国家标准方法测定大、中、小3种规格秋刀鱼肌肉的基本营养成分、脂肪酸组成和氨基酸组成, 比较其营养价值。结果 随着秋刀鱼规格的增大, 秋刀鱼肌肉中的粗脂肪含量增大, 而粗蛋白、水分含量减小; 3种规格秋刀鱼肌肉中均检测出18种氨基酸, 氨基酸总量为50.93~59.50 g/100 g, 且谷氨酸含量最高(7.00~8.39 g/100 g); 根据氨基酸评分,第一限制性氨基酸均为缬氨酸; 中规格秋刀鱼肌肉蛋白的必需氨基酸指数最高为88.44, 是良好蛋白源。不同规格秋刀鱼均富含多不饱和脂肪酸(47.23%~49.66%), 其中, 中规格秋刀鱼二十碳五烯酸和二十二碳六烯酸占总脂肪酸的比例最高为27.56%。结论 3种规格的秋刀鱼均属于高蛋白、高脂肪鱼类, 氨基酸和脂肪酸种类丰富且比例适中; 中规格秋刀鱼必需氨基酸指数最高, 二十碳五烯酸和二十二碳六烯酸的比例也最高, 营养价值相对较高。