维生素及矿物质对猪肉品质的营养调控

影响猪肉品质的因子很多,主要包括品种、性别、年龄、营养、环境、饲养方式和屠宰等。本文着重阐述了维生素和矿物质两种营养因子对猪肉品质的影响。     

青鱼饲料添加组氨酸的试验

鱼类对蛋白质的营养需要,实质是对氨基酸的需要,有关鱼类对氨基酸的数量及平衡的报道较多。但关于青鱼对游离氨基酸利用的研究不多,一般认为,鱼类对饲料中氨基酸和添加的游离氨基酸存在着吸收的不同步的现象,同时还影响别的必需氨基酸吸收的同步化,使氨基酸得不到平衡互补,从而影响游离氨基酸的结合率以至整个饲料蛋白质的利用。有的试验表明:添加游离氨基酸能     

浅谈减少PSE猪肉的饲料营养调控措施

在养猪生产中,随着饲料科技和育种工作的进步,猪的生产性能不断提高,但伴随而来的是猪肉品质的下降,劣质猪肉发生概率加大,典型的就是PSE猪肉。针对PSE猪肉产生机理、影响PSE肉产生的因素以及减少PSE肉发生率的饲料营养调控措施进行介绍。     

日粮营养水平与蓄禽繁殖性能

繁殖是畜禽的重要机能之一,也是畜牧生产的关键环节。畜牧生产的基础是繁殖数量多、品质优良的幼畜,以便用于畜牧生产和扩大再生产。影响畜禽繁殖性能的因素很多,营养是其中一个重要因素。能量、蛋白质、矿物质及维生素等营养物质对动物生殖的作用和动物繁殖机能均有较大影响。     

影响禽肉品质的营养因素及改进措施

随着人民生活水平的提高,消费者对肉质的要求越来越高,如何改变我国家禽数量增加但质量有所下降的现状,已成为我国家禽研究工作者的重要课题。影响禽肉品质的因素很多,其中营养因素和非营养因素对其影响较大,本文阐述了营养因素对禽肉品质的影响,并提出了相应的改进措施。1日粮     

小肽营养研究进展

小肽(sp)是动物降解蛋白质为氨基酸过程中的中间产物,对动物的重要营养有重要的营养作用。本文就小肽的吸收机制和特点、影响小肽释放和吸收的因素、小肽的营养作用以及其在动物营养中的应用等作一综述。     

日粮营养水平与畜禽繁殖性能

繁殖是畜禽的重要机能之一，也是畜牧生产的关键环节。畜牧生产的基础是繁殖数量多、品质优良的幼畜，以便用于畜牧生产和扩大再生产。影响畜禽繁殖性能的因素很多，营养是其中一个重要因素。能量、蛋白质、矿物质及维生素等营养物质对动物生殖的作用和动物繁殖机能均有较大影响。     

塞内加尔鳎仔稚鱼的营养生理研究进展

塞内加尔鳎分布于地中海和大西洋南部沿岸, 是一种优质养殖鱼类。我国于2005年引进, 到目前为止, 仅有小规模的养殖。本文介绍了塞内加尔鳎仔、稚鱼对蛋白质、氨基酸和脂肪酸的营养生理研究成果。主要包括大豆浓缩蛋白和花生四烯酸对塞内加尔鳎仔、稚鱼生长及生理的影响以及添加氨基酸、改变非蛋白能量水平、调节蛋白质和脂类比例对其营养生理的影响。研究结果表明: 大豆浓缩蛋白可部分替代鱼粉投喂塞内加尔鳎后期幼体, 对其生长没有显著影响, 但要先消除抗营养因子的作用; 氨基酸的添加可影响氨基酸代谢, 从而影响塞内加尔鳎后期幼体的生长。幼体饵料中添加的氨基酸种类应该和限制性氨基酸相一致; 塞内加尔鳎幼体的生长和存活不依赖于饲料中花生四烯酸的浓度, 但对色素沉着有影响。     

三疣梭子蟹营养和风味品质比较分析

三疣梭子蟹(Portunus trituberculatus)广泛分布于中国四大海域,以黄海、东海产量居高。三疣梭子蟹的蛋白质、脂肪、氨基酸和必需脂肪酸等成分含量可直接反映其营养品质,而游离氨基酸、脂肪酸、甜菜碱、核苷酸、糖原及矿物质等非挥发性成分和挥发性成分均与三疣梭子蟹的风味品质存在密切关系。文章根据近年来三疣梭子蟹营养和风味品质的相关研究成果,总结分析了三疣梭子蟹的性别、可食用部位以及养殖方式、成熟阶段及饵料组成等因素对三疣梭子蟹的营养成分及风味品质的影响,并对现有的营养成分的测定方法进行了归纳比较,以期为三疣梭子蟹的养殖生产及品质评价工作提供参考。     

塞内加尔鳎仔稚鱼的营养生理研究进展

塞内加尔鳎分布于地中海和大西洋南部沿岸,是一种优质养殖鱼类.我国于2005年引进,到目前为止,仅有小规模的养殖.本文介绍了塞内加尔鳎仔、稚鱼对蛋白质、氨基酸和脂肪酸的营养生理研究成果.主要包括大豆浓缩蛋白和花生四烯酸对塞内加尔鳎仔、稚鱼生长及牛理的影响以及添加氨基酸、改变非蛋白能量水平、调节蛋白质和脂类比例对其营养生理的影响.研究结果表明:大豆浓缩蛋白可部分替代鱼粉投喂塞内加尔鳎后期幼体,对其生长没有显著影响,但要先消除抗营养因子的作用;氨基酸的添加可影响氨基酸代谢,从而影响塞内加尔鳎后期幼体的生长.幼体饵料中添加的氨基酸种类应该和限制性氨基酸相一致;塞内加尔鳎幼体的生长和存活不依赖于饲料中花生四烯酸的浓度,但对色素沉着有影响.     

羊驼肉理化性状及食用品质研究

为评价羊驼肉的食用品质,试验采集9头羊驼肉作为样本,测定了羊驼肉肌红蛋白、系水率、蒸煮损失、剪切力、胶原蛋白、水分含量、粗蛋白、肌内脂肪和粗灰分的含量,初步建立了评定羊驼肉品质的方法。结果表明:羊驼肉的肌红蛋白、系水率、剪切力、胶原蛋白、蛋白质和肌内脂肪含量分别为8.2×10-2μmol/g、75.8%、4.7kg、3.4mg/g、25.6%、0.4%,羊驼肉中肌红蛋白含量低于牛肉;肉品的系水率较高,持水性较强,嫩度较猪肉差,但远优于牛肉;羊驼肉蛋白质和矿物质含量明显高于猪肉、牛肉,但肌内脂肪含量较低。总之,羊驼肉是一种优质的肉类资源,大有利用和开发前景。     

Evaluation of Protein Quality in Microbound Starter Diets Made with Decapsulated Cysts of Artemia and Fishmeal for Fish Larvae

Abstract.— The protein quality of carboxymethylcellulose microbound diets (MBDs) made with decapsulated cysts of Artemia andlor fishmeal as protein sources was used as an indicator of their suitability as starter feed for fish larvae. Studies on the proximate, fatty acid and amino acid composition. in vitro protein digestibility. diet solubility, and protein structure were combined with an in vivo feeding experiment with African catfish Clarias gariepinus larvae to evaluate the protein quality of the MBDs and a commercial diet. The growth of catfish larvae was higher when fed Artemia -based MBDs than with fishmeal-based MBDs, despite the higher protein and amino acid content of the latter. The in vitro protein digestibility was high for all the MBDs in comparison to a commercial diet. Differences were found in the protein molecular weight among the diets. Most of the proteins in the fishmeal-based diets had low molecular weight in the range between 7.4 and 49.2 kDa. The Artemia-based MBDs had larger protein fractions between 29.4 and 82 kDa. Decapsulated cysts improved the utilization of the MBDs when used in combination with fishmeal. Besides the effect of chemical attractants, the explanation for the positive effect of Artemia has yet to be elucidated. However, attention should be given to interactions between nutrients (e.g., protein-lipid) in live food, which might have an effect on the functional properties of food proteins.     

Growth performance and whole‐body composition of yellow catfish (Pelteobagrus fulvidraco Richardson) under feeding restriction

Fish growth is an important index in aquaculture practice. However, the effect of growth under restricted feeding on quality of fish grown to the same size remains poorly unknown. In this study, yellow catfish were reared by feeding them at three different feeding rates such as low (FR‐L group), medium (FR‐M group) and high (apparent satiation) ration levels for 82, 58 and 34 days to reach the same size, respectively. After this period, the growth performance, whole‐body amino acid composition and fatty acid profile of the fish were evaluated. Feeding restriction led to significant decreases in specific growth rate and feed conversion efficiency. Significant increases in dry matter, protein and energy contents were observed in fish under both restricted feeding treatments. FR‐L‐treated fish had significantly lower whole‐body essential amino acid contents, and significantly higher Ala and non‐essential amino acid contents compared to fish fed to satiation. Fish in restricted feeding treatments had significantly higher n‐3 PUFA and n‐3/n‐6 ratio compared to the fish fed to satiation. The present results indicate that from a quality perspective, there are certain advantages in improvement of whole‐body composition and enrichment of n‐3 PUFA associated with the restricted feeding of yellow catfish at slow growth rate.     

散鳞镜鲤、团头鲂及其杂交F1肌肉营养成分的比较

采用生化分析方法对散鳞镜鲤、团头鲂及其杂交F1肌肉的营养成分进行了测定并比较。结果表明，交杂种F1肌肉中的水分含量为77．89％、灰分含量为5．52％，均低于亲本；脂肪含量为4．77％，高于团头鲂，低于散鳞镜鲤；F1的氨基酸含量为77．89％，低于双亲，但大多成分含量与散鳞镜鲤相当。在总体水平上，杂交种品质得到初步的改良。     

蓝圆鲹肌肉中营养成分分析与评价

为了测定蓝圆鲹(Decapterus maruadsi)肌肉中的营养成分,并对其营养价值进行系统的分析及合理的评价,采用国家标准生化测定方法检测蓝圆鲹肌肉中的水分、粗蛋白质、粗脂肪、粗灰分、氨基酸、脂肪酸及矿物质。结果显示,蓝圆鲹肌肉中水分含量为75.00%,粗蛋白质、粗脂肪及粗灰分的干重含量分别为79.52%、9.88%和4.16%;共检出18种氨基酸,总含量为75.24%(干重),必需氨基酸占氨基酸总含量的30.08%,谷氨酸含量最高(11.40%),主要的限制氨基酸是色氨酸和缬氨酸,必需氨基酸指数EAAI为83.32;共检出17种脂肪酸,棕榈酸含量最高(2.60%),EPA+DHA含量为2.20%;富含磷(P)、钾(K)、钙(Ca)、钠(Na)、镁(Mg)等矿物质元素,常量元素中磷的含量最高(2 193.99 mg/kg),微量元素中铁的含量最高(22.25 mg/kg)。研究表明,蓝圆鲹是高蛋白低脂肪、营养价值及经济价值均较高的优质海洋经济鱼类,具有较好的综合开发利用价值。     

The whole amino acid profile as indicator of the nutritional condition in cultured marine fish larvae

The effect of variations in the amount or quality of food provided on the amino acid profile of larvae, was tested in two marine fish species, the Senegal sole (Solea senegalensis) and the sea bass (Dicentrarchus labrax). The objective was to assess whether such nutritionally suboptimum dietary patterns, which simulate situations that may occur in hatcheries, result in variations in the concentration of one or more amino acids that could be used as indicators of nutritional condition of larvae. Restriction in the normal food ration by 60% had no clear effect on the amino acid profile of sea bass, while the concentration of some amino acids (Arg, Ala and Phe) showed significant variations in sole. Feeding on artificial diets, which have shown their inadequacy a priori, resulted also in no significant effect on the profile of sea bass, but in a dramatic modification of the amino acid profile in sole. In addition, changes in the amino acid profiles considered as a whole were evaluated using the cluster analysis instead of paired comparisons between amino acid concentrations in each treatment. The analysis clearly separated profiles of larvae fed restrictedly or inadequately from their controls, irrespective of the species. This demonstrated the potential value of evaluating whole changes in amino acid profile as nutritional indicator. Besides, it was demonstrated that sensitivity of larvae to nutritional changes that may be reflected in the amino acid profile is greatly conditioned by the species and developmental stage.     

不同类型抗菌素对致病性鳗弧菌外膜蛋白表达的影响

摘要：对已分离的1株致病性鳗弧菌W1外膜蛋白图谱进行SDS-PAGE分析，并与8株不同血清型的鳗弧菌外膜蛋白进行比较。结果表明，鳗弧菌W1主要外膜蛋白分别为24kD，38kD，42kD和47kD，主要外膜蛋白图谱与鳗弧菌O1血清型标准菌株VIB1相似。抗生素药敏试验表明该菌对氨苄青霉素、强力霉素、磺胺嘧啶等14种常用药物产生了抗性，只对新生霉素、呋喃妥因、利福平、新霉素等9种药物敏感。研究不同浓度的氨苄青霉素、强力霉素、磺胺嘧啶和庆大霉素对鳗弧菌外膜蛋白表达的影响。结果表明，氨苄青霉素、强力霉素和磺胺嘧啶明显地抑制鳗弧菌42kD的主要外膜蛋白的表达，随着抗菌素浓度的增加，该外膜蛋白的表达量逐渐减少甚至消失，而庆大霉素浓度的变化对其表达没有明显影响。对该42kD主要外膜蛋白进行N末端分析表明，其N末端序列为EAPTAINS，与已发表的细菌其他外膜蛋白序列没有同源性。     

Effect of nitrogen and phosphorus on the growth and amino acid contents of Porphyra yezoensis

The effects of nitrogen fertilizer (NF) and phosphorus fertilizer (PF) on the growth as well as protein amino acid (PAA) and free amino acid (FAA) contents of Porphyra yezoensis in sea water were investigated. Single NF application did not improve P. yezoensis growth, but significantly increased its amino acid content. Single PF application significantly increased P. yezoensis growth, but decreased its amino acid content. Combined application of NF and PF could significantly promote the P. yezoensis growth, increase its amino acid content (including flavour amino acid) and thus improve its edible quality. Results indicate that combined application of NF and PF contributed to the growth and quality of P. yezoensis.     

Protein Hydrolysate from Visceral Waste Proteins of Bolti Fish (Tilapia nilotica): Chemical and Nutritional Variations as Affected by Processing pHs and Time of Hydrolysis

The main objective of the current work was to evaluate the proximate chemical composition and nutritional quality of amino acids of protein hydrolysates from viscera of Tilapia nilotica fish. The results of amino acid composition showed that all hydrolysates contained sufficient and/or excessive amounts of both essential and nonessential amino acids, with appreciable values of essential amino acid/nonessential amino acid ratio (0.77 to 1.59) and essential amino acid/total amino acid ratio (43.35 to 61.35). All protein hydrolysates had a high content of the flavor enhancer amino acids. The lowest values of essential amino acids were found for phenylalanine and methionine with chemical scores ranging from 0.04 to 0.77 and 0.09 to 1.06, respectively, except for 18 h hydrolysates. The protein efficiency ratio had values greatly exceeding 2.0, which is considered a high quality. On the other hand, the levels of sugar and ash contents ranged from 2.69 to 3.32 g L^?1 and 0.48 to 2.1%, respectively, with 9.2 to 14% dry matter. Mineral composition showed that sufficient amounts of calcium, sodium, potassium, magnesium, and iron were present. The results suggest that the studied hydrolysates are appropriate for use in balanced human or animal diets.     

马氏珠母贝肉的营养成分及其游离氨基酸组成

对马氏珠母贝肉的营养成分及游离氨基酸组成进行了较系统的食品化学特性研究,结果表明：马氏珠母贝含粗蛋白７４．９％（干基）,蛋白质的氨基酸组成中,富含Ｇｌｕ（２．２１％）、Ａｓｐ（１．４５）、Ｇｌｙ（１．０１％）等呈味氨基酸;蛋白质营养价高,氨基酸价为８２,第一限制氨基酸是含硫氨基酸（１９７３年（ＦＡＯ／ＷＨＯ标准）;无机盐含量丰富,尤其是微量元素Ｚｎ和Ｓｅ;游离氨基酸中,牛磺酸含量最高达１．３８％,