福瑞鲤与黄河鲤、建鲤鱼肉品质的比较及影响肉质的主成分分析

为研究福瑞鲤和黄河鲤、建鲤的肉质差异,选取了体质量相近、相同养殖条件下的3种鲤鱼,分析其质构特性、肉色、p H值变化及营养成分。结果表明:福瑞鲤剪切力、硬度、胶黏性、咀嚼性指标低于黄河鲤和建鲤,而黏附性高于黄河鲤;水分含量、脂肪含量极显著低于黄河鲤及建鲤(P0.01),灰分含量、蛋白质含量没有显著差异(P0.05),Ser、Cys含量以及必需氨基酸(essential amino acids,EAA)含量较高,Thr含量较黄河鲤、建鲤有很大提升。整体上来说,福瑞鲤鱼肉品质在质构性能和营养价值上要优于黄河鲤和建鲤。而相关性分析表明剪切力、硬度、胶黏性、咀嚼性4项指标均与粗蛋白、粗脂肪含量两项指标成显著正相关(P0.05);黏附性与粗脂肪含量成负相关(P0.05);从12项指标中提取出3个主成分,硬度、剪切力、粗脂肪、粗蛋白为影响肉质性能的最主要因素。     

不同日龄和性别白羽王鸽肉品质、主要营养成分及肌纤维特性的比较研究

目的比较研究不同日龄和性别白羽王鸽胸肌肉的常规肉品质、主要营养成分和肌纤维特性。方法随机选取健康28日龄乳鸽、600日龄左右老鸽公(♂)母(♀)各30只,屠宰取胸肌待测。使用色差仪、pH计、膨胀仪、肌肉嫩度仪等测定常规肉品质指标,参照国标方法测定营养成分,制作石蜡切片并通过生物显微镜观察肌纤维特性。结果乳鸽胸肌肉肉色a值和b值均极显著高于老鸽(P0.01);乳鸽胸肌肉pH高于老鸽,且乳鸽(♂)显著高于老鸽(♂)(P0.05);不同日龄和性别对白羽王鸽胸肌肉失水率没有显著影响(P0.05);老鸽胸肌肉剪切力大于乳鸽,且老鸽(♂)显著大于乳鸽(♀)(P0.05)。不同日龄和性别白羽王鸽胸肌肉水分含量无显著差异(P0.05),蛋白质和脂肪含量有显著差异(P0.05);蛋白质和脂肪含量:老鸽(♀)老鸽(♂)乳鸽(♀)乳鸽(♂)。乳鸽胸肌肉肌纤维饱满致密,老鸽细且纤维之间的空隙较大。老鸽胸肌肉的肌纤维密度极显著高于乳鸽(P0.01),肌纤维直径极显著低于乳鸽(P0.01);相同日龄公母鸽胸肌肉肌纤维密度和肌纤维直径没有显著差异(P0.05)。结论性别仅对白羽王鸽胸肌肉中蛋白质和脂肪的沉积有影响,对常规肉品质和肌纤维特性影响不大。日龄对白羽王鸽胸肌肉的肉品质、微观结构和化学成分均有影响。乳鸽肉色红润,肉质鲜嫩,肌纤维饱满,脂肪含量低;老鸽肌纤维细密,肌间脂肪和蛋白含量高。     

日粮维生素E水平对鲤生长性能和肌肉品质的影响

本文旨在研究日粮中添加不同水平的维生素E对鲤长性能、肌肉组成及其贮藏品质的影响。选取360尾健康的鲤,平均体重(97.17±6.01)g,随机分成6个处理,分别投喂在基础饲料中添加0、100、300、500、700和900 mg/kg维生素E的试验饲料,每个处理3个重复,每个重复20尾,试验期60 d。结果表明：随维生素E水平的升高,鲤增重、特定生长率呈先升后降趋势,均为维生素E添加量达500 mg/kg时最高;饵料系数呈相反的趋势,当维生素E添加量达500 mg/kg时最低;维生素E对肠长指数(RGL)没有影响,对照组鲤的肠体指数(ISI)显著(P<0.05)大于其余各组,肥满度(CF)显著(P<0.05)高于其余各组;随维生素E水平的升高,肝胰指数(HIS)呈先升后降趋势,700 mg/kg组最高,显著(P<0.05)高于对照组和100 mg/kg组;以增重、特定生长率及饵料系数为指标,利用折线模型分析表明,鲤生长性能最佳时维生素E添加量为466.33～478.25 mg/kg。维生素E对鲤肌肉组成有显著(P<0.05)影响。当维生素E添加量为700 mg/kg时干物质含量显著(P<0.05)大于对照组;当维生素E添加量在300~700 mg/kg时粗蛋白含量显著(P<0.05)大于对照组;对照组的粗脂肪含量显著(P<0.05)高于其余各组,在100~900 mg/kg范围内,除700 mg/kg 组的粗脂肪含量显著(P<0.05)低于100 mg/kg组外,其余各组差异不显著(P>0.05)。利用三次多项式模型分析表明,当维生素E添加量为636.36 mg/kg时,鲤肌肉粗蛋白含量最高。在肌肉贮藏品质方面,肌肉滴水损失、渗出损失、TVB-N和TBARS值随饲料中维生素E添加量的增加而显著(P<0.05)降低,均在维生素E添加量为900 mg/kg时达最低。     

5种不同花斑黄鳝肌肉品质的差异性分析

为分析大花斑、碎花斑、细花斑、隐花斑、黄黑斑5种不同花斑黄鳝肌肉品质的差异性,采用物性分析、组织切片及生化分析等方法对5种不同花斑黄鳝肌肉的质构特性、肌纤维特性及营养成分进行测定。结果显示:口感方面,隐花斑黄鳝肌肉的硬度和咀嚼性显著大于大花斑、碎花斑和黄黑斑(P0.05),细花斑黄鳝次之;黄鳝肌纤维直径的平均值以细花斑黄鳝显著最小(P0.05),碎花斑黄鳝最大。营养成分方面,粗脂肪含量以细花斑黄鳝显著低于大花斑黄鳝(P0.05),其他花斑黄鳝差异不显著(P0.05)。17种检出氨基酸中,氨基酸总量、必需氨基酸总量及鲜味氨基酸总量均以细花斑黄鳝含量最高,碎花斑黄鳝含量最低,且二者差异显著(P0.05)。测定的17种脂肪酸中,豆蔻酸和棕榈一烯酸均以隐花斑黄鳝和碎花斑黄鳝含量显著大于黄黑斑黄鳝(P0.05),花生三烯酸和花生四烯酸及多不饱和脂肪酸总量均为黄黑斑黄鳝含量显著大于隐花斑黄鳝(P0.05),其他花斑黄鳝差异不显著(P0.05)。结果表明,5种不同花斑黄鳝肌肉品质存在一定差异,且综合来看,细花斑黄鳝肌肉的品质更具优势。     

养殖中华鲟肉质、营养成分及风味分析

为了研究宣城地区人工养殖中华鲟肉质、营养成分和风味,以6尾质量为(1803.4±17.9)g的宣城地区人工养殖中华鲟为研究对象,对其肉质、营养成分及风味进行分析。结果表明,中华鲟背部的亮度、红度、失水率、蒸煮损失和肌纤维直径高于腹部,而黄度、p H、嫩度、滴水损失和肌纤维密度低于腹部。中华鲟水分含量、粗脂肪含量、可溶性蛋白质和灰分含量分别为76.89%、1.47%、19.86%和0.93%,肌肉中K含量最高,此外还含有丰富的微量元素Fe、Zn、Cu和Se等。经GC-MS分离鉴定,中华鲟中共有42种挥发性成分,其中,醛类(20.65%)、烃类(62.41%)、酯类(5.50%)和含硫、含氮、含氧及杂环化合物(6.59%)是中华鲟风味物质的主要成分。此结果可为中华鲟精深加工生产提供工艺设计参考和理论依据。     

藏猪与大白猪食用品质与肌纤维类型的相关性研究

为了探究不同地区猪肉品质差异及形成原因,本研究选取不同地区（西藏林芝、甘肃甘南、四川阿坝）自然放养下的藏猪与平原大白猪为研究对象,测定其背最长肌的食用品质（pH、颜色、蒸煮损失、剪切力）、肌红蛋白含量、羟脯氨酸含量、不同的肌球蛋白重链（MyHC）mRNA相对表达量,并对各指标进行相关性分析。结果表明,藏猪的pH_{3 h}处于5.7~5.8,显著低于大白猪（6.05±0.20,P<0.05）,藏猪的红度值（a*）和肌红蛋白含量显著高于大白猪（白猪为2.12±0.87、0.004 μmol/g）,其中,阿坝藏猪的a*最高（8.10±0.99）（P<0.05）;藏猪的剪切力和羟脯氨酸含量显著高于大白猪（41.81±0.83、5.92%±0.52%）（P<0.05）;藏猪的IIa型肌纤维比例显著高于大白猪而IIb型肌纤维比例显著低于大白猪（P<0.05）;相关性分析表明,a*与L*、IIb型肌纤维呈极显著负相关（P<0.01),与肌红蛋白含量、I型和IIa型肌纤维呈极显著正相关（P<0.01）,剪切力与羟脯氨酸含量呈现极显著正相关（P<0.01）。综上所述,藏猪大白猪肉的食用品质差异很大,藏猪比大白猪的肉色更红、嫩度更差,不同地区藏猪肉色也存在一定差异,这与它们的肌肉纤维类型有很大相关性。     

利用SUSAN边缘检测自动估算牛肌纤维直径

肌纤维是肌肉组成的基本单位,是衡量牛肉嫩度和肉色的参考依据。肌纤维测定基本内容包括肌纤维密度和肌纤维直径。本研究以甘南牦牛和黄牛前肢肌肉为试验材料,利用SUSAN边缘检测算法对牛肌纤维超微结构进行边缘特征提取,再利用检测出的边缘实现图像分割,计算出各个分块的直径并求平均数,即得牛肌纤维直径。通过大量实验数据表明,利用本算法自动分割牛肌纤维超微结构是可行的,并可以快速无损的估算出牛肌纤维的直径,为基于计算机视觉的牛肉品质自动检测打下基础。     

欧洲肉鸽与其他畜禽肉品质及主要营养成分比较分析

目的测定欧洲肉鸽胸肌肉的常规肉品质(肉色、p H、失水率和剪切力)和主要营养成分(蛋白、脂肪、氨基酸和脂肪酸)。方法使用色差仪、p H计、膨胀仪、肌肉嫩度仪等测定品质指标,参照国标方法和常用方法测定营养成分,并与其他禽肉进行比较分析。结果与其他常规畜禽肉相比,欧洲肉鸽肉色偏红偏暗,p H适中,失水率最高,剪切力最低;鸽肉的水分含量高于其他肉类,蛋白质含量最高为20.5%,脂肪含量最低仅2.7%;鸽肉中氨基酸含量丰富,必需氨基酸含量占40.80%,鲜味氨基酸含量占43.42%,均高于其他畜禽肉;鸽肉中脂肪酸种类丰富(11种),所含多不饱和脂肪酸含量最高,其中亚油酸的含量明显高于其他畜禽肉类。结论欧洲肉鸽色泽红润,滑嫩多汁,氨基酸含量丰富,脂肪酸组成优化,是一种高蛋白、低脂肪的理想型食用肉类。     

补饲和放养牦牛肉品质及肌肉微观结构差异

为研究补饲和放养牦牛肉品质及肌肉微观结构的差异,选取青海省海北州天然放养的12头牦牛,随机分为补饲组和放养组,屠宰后分别取2组牦牛的冈上肌、背阔肌和半腱肌,并对其食用品质、营养品质及肌肉微观结构进行测定分析。结果表明:补饲牦牛背阔肌和半腱肌的亮度(L*值)分别较放养牦牛高1.09和2.99,3个部位肉的p H值、持水力和剪切力均低于放养牦牛,每个部位肉的脂肪含量较放养牦牛高42%以上,且肌纤维横截面积、肌纤维直径、肌纤维膜厚度、Ⅰ带和A带均极显著低于放养牦牛(P<0.01),但肌纤维密度极显著高于放养牦牛?(P<0.01)。提示,补饲牦牛肉的肉色较好,肌纤维较细,嫩度好,但是持水力较差,脂肪含量高。     

小尾寒羊不同部位羊肉理化特性及肉用品质的比较

以我国著名的优良品种小尾寒羊为研究对象,对其不同分割部位(脊背、腰窝、肋条、前腿、后腿、腱子)羊肉的理化特性进行测定,并对其熟制品(牙签肉)食用品质进行比较.结果表明,根据理化性质不同可将不同分割部位分成臀腿部和躯干部两部分,肉品的脂肪含量、颜色、失水率、剪切力、肌纤维直径和密度有显著差异(p<0.05).肌肉脂肪含量明显影响羊肉产品风味,可作为羊肉风味的评价指标.肌纤维的组织学特性和剪切力都可作为嫩度的评价指标.肋条和腰窝部位肌肉脂肪含量较高,肌肉肌纤维直径细、密度大,系水力较强,剪切力小,肉质较嫩,香气浓郁,因此具有较好的食用品质,是制作烧烤涮羊肉制品的最佳原料.     

Probiotics and prebiotics--perspectives and challenges

Owing to their health benefits, probiotics and prebiotics are nowadays widely used in yogurts and fermented milks, which are leader products of functional foods worldwide. The world market for functional foods has grown rapidly in the last three decades, with an estimated size in 2003 of ca US$ 33 billion, while the European market estimation exceeded US$ 2 billion in the same year. However, the production of probiotics and prebiotics at industrial scale faces several challenges, including the search for economical and abundant raw materials for prebiotic production, the low-cost production of probiotics and the improvement of probiotic viability after storage or during the manufacturing process of the functional food. In this review, functional foods based on probiotics and prebiotics are introduced as a key biotechnological field with tremendous potential for innovation. A concise state of the art addressing the fundamentals and challenges for the development of new probiotic- and prebiotic-based foods is presented, the niches for future research being clearly identified and discussed.     

常用消毒灭菌法及其机理与应用

介绍了采用消毒灭菌方法,有加热消毒法,紫外线辐射法和化学药剂消毒法。常用化学药剂有醛类、含氯消毒剂、醇类消毒剂以及高锰酸钾、生石灰等,阐释了消毒与灭菌两个概念的区别。     

European citizen and consumer attitudes and preferences regarding beef and pork

This paper presents the combined mid-term findings of the consumer research components of two EU Sixth Framework Programme integrated projects concerning meat, ProSafeBeef and Q-PorkChains. The consumer pillar of ProSafeBeef carried out eight focus group discussions in May 2008, in France, Germany, Spain and the UK. Q-PorkChains conducted a large-scale, web-based, consumer survey in January 2008 in Belgium, Denmark, Germany, Greece and Poland. The first project provides a set of qualitative data from a small cohort of focus groups and the second a set of quantitative data from a larger consumer sample. This paper draws together the main findings of both projects and provides a comprehensive overview of European citizens’ and consumers’ attitudes towards and preferences regarding beef and pork. In general, consumers consider meat to be a healthy and important component of the diet. Consumers support the development of technologies that can improve the health attributes of meat products and guarantee eating quality, but they have a negative view of what they see to be excessive manipulation and lack of naturalness in the production and processing of beef products. In the Q-PorkChains study consumer and citizen segments are identified and profiled. Consumer segments were built upon the frequency and variety of pork consumption. The citizen segments were built upon their attitudes towards pig production systems. Overall, the relationship between individuals’ views as citizens and their behaviour as consumers was found to be quite weak and did not appear to greatly or systematically influence meat-buying habits. Future studies in both projects will concentrate on consumers’ acceptance of innovative meat product concepts and products, with the aim of boosting consumer trust and invigorating the European beef and pork industries.     

益生素、益生菌与结肠癌

介绍了益生素和益生菌及其作用机理。在动物模型中，有大量的数据证实益生素和益生菌能够预防癌症．而在人体内还没有直接实验证据。它们抑制癌症的确切机理目前尚不清楚，其抑制机理可能是：肠道菌群代谢活动的改变，肠道理化环境的改变，潜在的致癌物质的黏附和降解，肠道菌群的改变、抗癌或抗诱变物质的形成、提高宿主的免疫应答、影响宿主的生理活动以及发酵不能被消化的食物并形成有益代谢产物。     

节能节水型印染助剂和设备的现状

从节能、节水、缩短工艺流程和环保的角度出发，介绍了国内外研制开发的一系列新型节能、节水型印染助剂和染整设备。     

Heritability and correlations for body condition score and dairy form within and across lactation and age

The objectives of the current study were to investigate the relationship between body condition score (BCS) and dairy form and changes in genetic parameters for BCS and dairy form within and across lactations and age. Body condition score and dairy form were obtained from the Holstein Association USA, Inc. Records were edited to include those cows classified between 24 and 60 mo of age and between 0 and 335 d in milk (DIM). A minimum of 20 daughters per sire and 15 cows per herd-classification visit were required. The dataset consisted of 135,178 records from 119,215 cows. Repeatability, multiple trait, and random regression models were used to analyze the data. All models included fixed effects for herd-classification visit, age within lactations 1, 2, and 3 or higher, and 5th-order polynomials for DIM. Random effects included sire and permanent environment for all models. Random regression models included age at classification nested within sire or DIM and lactation number nested within sire. Genetic variance for both BCS and dairy form was lowest in early lactation and highest in midlactation. Genetic correlations within and across lactations were high. The genetic correlation between DIM 0 in lactation 1 and DIM 305 in lactation 3 was estimated to be 0.77 for BCS and 0.60 for dairy form. The genetic correlation estimate between 30 mo of age at classification and 50 mo of age at classification was 0.94 for both dairy form and BCS. The repeatability models appeared to generate accurate evaluations for BCS or dairy form at all ages and stages of lactation.     

组学技术与果蔬采后质量和安全控制

果蔬可以提供营养, 有利于人类健康, 而果蔬的后熟及其与环境的相互作用会影响果蔬采后的质量和安全。对果蔬生物学过程的了解和掌握是减少果蔬采后损失和保障果蔬采后质量和安全的关键。在过去的10多年, 基于组学技术的系统生物学在了解果蔬后熟及其与环境相互作用的分子机制方面得到了越来越多的应用。本文对此做了细致的总结, 指出了存在的不足, 并提出了未来的发展方向。     

原花色素及其开发应用

对原花色素的结构、化学特性、制备、分析方法、应用前景作一综述,并重点讨论其生理功能,为在功能性食品、药物、化妆品等领域的深入研究和开发提供参考。     

Dioxins and PCBs in ostrich meat and eggs: levels and implications

ABSTRACT

Although consumption of eggs is an essential part of our diet, limited information is available for table eggs other than those laid by hens. The aim of our study was to determine concentrations of polychlorinated dibenzofurans (PCDD/Fs), dioxin-like (DL-) and non-dioxin-like (NDL) polychlorinated biphenyls (PCBs) in ostrich eggs and meat available on the Polish market, in order to obtain baseline information on the current status of these pollutants in comparison to poultry products. Obtained data were compared with the binding EU limits set for chicken eggs and meat. The levels of individual PCDD/Fs and PCBs congeners varied considerably. The percentage share of total WHO toxic equivalency factor (WHO-TEQ) content indicates the dominant role of PCDD/Fs. High concentrations of PCDD/F and DL-PCBs, in the range of 0.85–74.48 pg WHO-TEQ g^?1 fat, were found in ostrich eggs; this exceeds the maximum level permitted for chicken eggs by a factor of up to 15. Eight of the 11 egg samples exceeded the action level for hen eggs. Although the ostrich meat concentrations of PCDD/Fs do not exceed the limit established for poultry muscle (1.75 pg g^?1 fat), average contents of PCDD/Fs exceeded almost four times the levels in chicken and turkey muscle. Human exposure was evaluated and the resulting risk was characterised. Taking into account the low average consumption of ostrich eggs, the resulting exposure to dioxins for the general population can be considered as negligibly low. However, the individuals who frequently consume such eggs may be at risk of elevated exposure. Although ostrich products are not consumed frequently, such data are nevertheless useful for food safety purposes.     

天然香精香料与生物技术

天然香精香料是高价值的精细化工产品和食品添加剂,但原料来源有限且提取成本高。利用生物技术生产这类产品具有广阔的前景。简述了发酵工程、酶工程、细胞工程和基因工程在香精香料中的应用,并探讨了生物技术在香精香料中的应用前景。