Compositional and functional properties of milk and dairy products derived from cows fed pasture or concentrate-based diets

Worldwide milk production is predominantly founded on indoor, high-concentrate feeding systems, whereas pasture-based feeding systems are most common in New Zealand and Ireland but have received greater attention recently in countries utilizing conventional systems. Consumer interest in ‘pasture-fed’ dairy products has also increased, arising from environmental, ethical, and nutritional concerns. A substantial body of research exists describing the effect of different feeding strategies on the composition of milk, with several recent studies focusing on the comparison of pasture- and concentrate-based feeding regimes. Significant variation is typically observed in the gross composition of milk produced from different supplemental feeds, but various changes in the discrete composition of macromolecular components in milk have also been associated with dietary influence, particularly in relation to the fatty acid profile. Changes in milk composition have also been shown to have implications for milk and dairy product processability, functionality and sensory properties. Methods to determine the traceability of dairy products or verify marketing claims such as ‘pasture-fed’ have also been established, based on compositional variation due to diet. This review explores the effects of feed types on milk composition and quality, along with the ultimate effect of diet-induced changes on milk and dairy product functionality, with particular emphasis placed on pasture- and concentrate-based feeding systems.     

Impacts of Milk Fraud on Food Safety and Nutrition with Special Emphasis on Developing Countries

Milk in its natural form has a high food value, since it is comprised of a wide variety of nutrients which are essential for proper growth and maintenance of the human body. In recent decades, there has been an upsurge in milk consumption worldwide, especially in developing countries, and it is now forming a significant part of the diet for a high proportion of the global population. As a result of the increased demand, in addition to the growth in competition in the dairy market and the increasing complexity of the supply chain, some unscrupulous producers are indulging in milk fraud. This malpractice has become a common problem in the developing countries, which lack strict vigilance by food safety authorities. Milk is often subjected to fraud (by means of adulteration) for financial gain, but it can also be adulterated due to ill‐informed attempts to improve hygiene conditions. Water is the most common adulterant used, which decreases the nutritional value of milk. If the water is contaminated, for example, with chemicals or pathogens, this poses a serious health risk for consumers. To the diluted milk, inferior cheaper materials may be added such as reconstituted milk powder, urea, and cane sugar, even more hazardous chemicals including melamine, formalin, caustic soda, and detergents. These additions have the potential to cause serious health‐related problems. This review aims to investigate the impacts of milk fraud on nutrition and food safety, and it points out the potential adverse human health effects associated with the consumption of adulterated milk.     

Amino acid enrichment and compositional changes among mammalian milk proteins and the resulting nutritional consequences

Milk is a hallmark of mammalian evolution: a unique food that has evolved with mammals. Despite the importance of this food, it is not known if variation in AA composition between different species is important to milk proteins or how it might affect the nutritional value of milk. As milk is the only food source for newborn mammals, it has long been speculated that milk proteins should be enriched in essential AA. However, no systematic analysis supports this assumption. Although many factors influence the overall nutritional value of milk, including total protein concentration, we focused here on the AA composition of milk proteins and investigated the possibility that selection drives compositional changes. We identified 9 major milk proteins present in 13 mammalian species and compared them with a large group of nonmilk proteins. Our results indicate heterogeneity in the AA composition of milk proteins, showing significant enrichment and depletion of certain AA in milk-specific proteins. Although high levels of particular AA appear to be consistently maintained, orthologous milk proteins display significant differences in AA composition across species, most notably among the caseins. Interspecies variation of milk composition is thought to be indicative of nutritional optimization to the requirements of the species. In accordance with this, our observations indicate that milk proteins may have adapted to the species-specific nutritional needs of the neonate.     

Computer model for municipal solid waste treatment in developing countries

Many integrated solid waste management (ISWM) models are available but are of little use to developing countries such as India since they do not take into account typical developing countries municipal solid waste characteristics such as high organic content, poor performance of formal sector control and support, high activity of scavengers and waste pickers, etc. The goal of this study is to create a computer program to determine the least cost treatment and disposal system for a given solid waste management problem. To demonstrate its applicability, the model was applied to the Indian city Amritsar. A typical Indian city like Amritsar generates about 500 ton of MSW/d with 45% moisture content, 30% volatile matter, and calorific value of 1500 kcal/kg. The computer model was run for various technologies. Results showthatfor Amritsar city incineration an expenditure of U.S. dollars (USD) 6.62 is incurred, whereas landfilling, composting, and biomethanation digester give an income of USD 0.13, USD 0.20, and USD 0.23 per ton of MSW, respectively. This empirical exercise not only reveals the model's strengths such as highlighting important interdependencies in the waste management sector but also its requirement for quality data.     

Composition of raw milk from sustainable production systems

Organic milk production has increased rapidly in many European countries during the last decade but the merits of organic dairy products are still disputed. Little unbiased information exists regarding any essential differences in gross composition or other parameters of technological and/or nutritional interest. In order to gather more basic information regarding organic milk, raw milk samples from 31 organic dairy farms in Sweden were collected once a month during 1 year. The samples were analyzed for gross composition, somatic cells, fatty acids, urea, iodine and selenium. As a reference, milk composition data from similar conventional farms was obtained.The results show small or no differences in the investigated parameters between organic milk and the milk from the conventional farms or average values regarding gross composition of Swedish raw milk. The only significant differences found were in urea content and somatic cells, both of which were lower in organic milk. In addition, levels of selenium were lower in organic milk, which is of nutritional importance since dairy products are significant dietary sources of selenium in Scandinavian diets.     

THE PRESENT NUTRITIONAL STATUS OF MILK PROTEINS

The role of milk and milk products as a source of protein required for human needs is assessed and various methods of determining the nutritional value of protein described. Biological value of milk protein and amino acids composition are compared and the importance of concentrated lysine is emphasized. The effect of heat treatment on whey proteins is discussed with the possibility of Maillard reaction. The future developments in milk protein with its high nutritional value and the necessity for new ways of using it as a food are stressed.     

Cowpea flour: A potential ingredient in food products

Cowpeas (Vigna unguiculata L. Walp) are an important grain legume in East and West African countries as well as in other developing countries. The U.S. is the only developed country producing large amounts of cowpeas. High protein (18 to 35%) and carbohydrate (50 to 65%) contents, together with an amino acid pattern complementary to that of cereal grains, make cowpeas potentially important to the human diet from a nutritional standpoint. Despite their potential as an inexpensive source of protein and energy, cowpeas are underutilized in the U.S. and other industrialized countries. A simple technology for preparing cowpea flour would stimulate increased consumption of this legume. This paper reviews the status of cowpea flour production technologies and uses of cowpea flour in various food products.     

代谢组学在牛奶质量安全中的应用研究进展

牛奶作为一种老少皆宜的食品,具有丰富的营养价值。近年来,牛奶质量与安全问题受到广泛关注,鉴别牛奶质量与安全性成为乳制品研究的主要方向之一。牛奶中含有许多代谢物,包括主要营养元素以及药物残留。代谢组学作为研究食品质量与安全的一类重要方法,可以大规模、高通量的揭示食品的质量安全问题。该文综述了代谢组学技术在牛奶质量与安全领域的应用。分析了对不同品种奶牛、不同加热方式以及不同环境和饲粮条件下得到的牛奶代谢物差异与牛奶质量的相关性;并总结了代谢组学技术鉴定牛奶中药物残留的应用,该技术可识别牛奶掺假问题;同时归纳了不同技术方法在牛奶质量和安全领域应用的特点。总之,该文阐明了代谢组学在鉴定牛奶品质中的应用范围,总结了近年来代谢组学在牛奶质量和安全方面的进展。     

绵羊奶组成和营养特性

绵羊奶是我国乳制品工业的"新增量",养殖规模和产奶量快速上升,然而,我国目前的绵羊奶产业水平还处于初级阶段,规模化加工制品几乎为零.绵羊奶营养价值高,总固形物在各种乳源中含量最高,除了具有较高含量的蛋白质、脂肪、矿物质和维生素以外,绵羊奶的活性功能因子丰富,乳铁蛋白、活性肽、乳脂肪球膜及低聚糖的组成、含量和生物活性与牛...     

山羊乳及其制品营养与功能特性的研究进展

山羊乳及相关制品由于丰富的营养价值和良好的健康功效受到越来越多消费者的关注。山羊乳属于一种资源稀缺型特种乳,与牛乳相比,其干物质含量较高、易消化,且致敏性较低,还是多种生物活性成分的良好来源。因此,山羊乳可用于加工制作适合各种人群的保健性能产品,也可作为益生元和益生菌等功能成分的载体。本文就山羊乳营养成分、功能特性以及加工处理等研究领域的前沿成果进行综述,着重介绍山羊乳相关制品预防与缓解多种疾病的作用与机制,为山羊乳高值化产品的开发提供参考。     

乳清产品在冰淇淋和冷冻乳制品甜食中的应用

<正> 乳清和乳清蛋白产品在过去的60多年中已经被成功应用于冰淇淋和其他冷冻乳制品甜食中。甜乳清、乳清浓缩蛋白(蛋白质含量34～89%)和乳清分离蛋白(蛋白质含量≥90%)是最常用的乳清产品。其他的乳清配料,如脱乳糖乳清和脱盐乳清也是常用的配料。成本优势和提升产品质量是使用乳清产品的主要出发点,     

生乳中体细胞数对乳品质量安全的影响研究进展

体细胞数增加会改变乳成分、影响牛乳风味及缩短乳制品货架期,并且使乳中抗生素和药物残留的风险增加。乳中体细胞数是衡量乳畜健康、乳品质量与安全的标准,也是国际判定隐形乳房炎的重要指标。为了保障乳品质量和安全,许多国家规定了生乳中体细胞数的限量。本文从体细胞数和乳品质量与安全的关系、不同国家对生乳中体细胞数的限量及影响体细胞数的因素和体细胞数的检测方法等方面作一综述。     

乳蛋白中乳清蛋白与酪蛋白组成、特性及应用的研究进展

乳清蛋白和酪蛋白是乳蛋白的主要组成成分,具有很高的营养价值。本文从乳中的乳清蛋白与酪蛋白出发,阐述了牛、羊等乳中乳清蛋白和酪蛋白的组成,并分别分析了乳清蛋白和酪蛋白的功能及其相关应用,综述了有关乳清蛋白和酪蛋白的新产品开发及综合利用,以期对乳中蛋白营养价值综合利用提供相应依据,为乳业相关企业及相关专业研究人员提供参考。     

Milk Processing in Rural Areas to Support Dairying in Developing Countries

Postcolonial collaboration in dairying between developed and developing countries has been taking place for 30 yr. The result of that collaboration has not always been successful. North – South transfer of dairying systems often leads to “development ruins”. For people in developing countries, milk is a valuable supplement but not a basic food. Nevertheless, milk processing may contribute to building up a rural industry based on agriculture. The rural location of such an industry provides additional working and earning opportunities and counteracts rural exodus. To avoid expensive, artificial cooling, and road transports, the collection radius for milk should be small. This leads to decentralized milk processing in small rural plants. The simple equipment of such plants should be manufactured in the developing country itself. Thus, milk processing may promote development of other sectors of domestic industry and become less dependent on imported equipment, which is difficult to maintain and replace. Plants and equipment have to be adapted to the special conditions in a developing country as well as the products. They should have good shelf-life, be marketable without artificial cooling, and be within reach of people with modest purchase power.     

Socioeconomic Aspects of Dairying in Developing Countries

Development of economically viable and socially acceptable dairy production systems in developing countries requires simultaneous consideration of production, distribution, and pricing aspects. Integration of dairying can best proceed through focusing on a local point of daily contact with farmers such as a collection center or processing plant.Total demand for milk and milk products is forecast to grow most rapidly in the Latin America and Far East regions. Chronic surpluses of the major dairy product traded internationally, nonfat dry milk, will keep international prices relatively low and force most developing countries to subsidize local milk production, at least in initial stages of development.Four basic types of dairying systems for developing countries are defined by criteria of specialization, use of milk, feeding systems, and animal species. Input-output relationships for some of these systems are discussed. Milk transportation and procurement problems for each class also are summarized.The organization and efficiency of milk procurement, processing, and distribution are seen as critical factors in eliciting the needed production response from small holders in developing countries. Minimum sizes for collection and processing systems are summarized. Finally, the potential role of dairying in rural development is discussed, and factors critical for success are listed.     

液态羊乳的加工研究进展

进入营养健康时代,消费需求不断升级,功能、营养、个性化的产品越来越受到重视。羊乳一直是人类营养的重要组成部分,与牛乳相比,羊乳的营养价值相对较高,凝乳的形成更柔软,乳脂肪小球的比例更高,致敏性低,与人乳更接近,是许多重要营养素的良好膳食来源。除了羊乳的许多有益作用外,饲养山羊和绵羊的优势,如动物成本较低、对饲料和水的需求较少及通常不需要大型牲畜所需的专门住房,也是促进全球羊乳生产改善的原因。然而,羊乳的热稳定性差,加工和贮藏过程中容易出现蛋白变性、沉淀、结块等质量缺陷,常温加工技术仍不成熟、货架期品质稳定性亟待提升。因此,本文对液态羊乳的加工技术、加工现状以及发展动态进行综述,为进一步开发常温液态羊乳奠定理论基础。     

Nutritional improvement of cereals by fermentation

Cereal grains form a major source of dietary nutrients for all people, particularly those in the developing countries. However, compared with animal foods, nutritional quality of cereal grains is inferior due to lower protein content, deficiency of certain essential amino acids, lower protein and starch availabilities, and the presence of some antinutritional factors. Fermentation of cereals for a limited period of time improves amino acid composition and vitamin content, increases protein and starch availabilities, and lowers the levels of antinutrients. In this review, the available literature concerning the nutritional improvement of cereals by fermentation has been compiled and is critically analyzed. The traditional foods prepared by fermentation of cereals in different parts of the world are briefly described and future research needs to improve their nutritional contribution are addressed.     

牛奶大豆双蛋白营养酸奶的研究

大豆蛋白质的氨基酸组成与牛奶蛋白质相近,除蛋氨酸略低外,其余必需氨基酸含量均较丰富,是植物性的完全蛋白质,在营养价值上,可与动物蛋白等同。大豆磷脂作为营养补助品已有七十多年历史,国外称其为“头脑补助食品”。用大豆分离蛋白、大豆磷脂和鲜牛奶制作的酸奶具有很高的营养价值和保健功能。     

核桃大豆植物奶加工工艺研究及品质分析

目的 深入探究核桃大豆植物奶的加工工艺,提升产品感官品质和营养价值。方法 研究大豆磨浆温度、磨浆pH和高压均质压力等因素对产品感官品质的影响,确定最佳加工条件,并探讨不同预处理方式对产品品质的影响。结果 实验研究了大豆磨浆温度、pH和均质压力的最佳组合,并进行了正交试验以优化加工工艺,最终确定大豆磨浆温度80℃、大豆磨浆pH 8.0、豆浆高压均质压力75 MPa的工艺条件,产品的感官评分最高。对比了不同预处理工艺对产品常规理化性质和香气品质的影响,发现浸泡条件显著改变豆浆中的可溶性固形物含量,进而影响产品的品质和营养价值,香气分析揭示了醛类化合物在豆腥味中的重要作用。结论 通过优化加工工艺,显著改善了产品的感官品质和营养价值,为核桃大豆植物奶的工业化生产提供了重要参考。     

Raw milk from vending machines: Effects of boiling,microwave treatment,and refrigeration on microbiological quality

In Italy, the sale of raw milk from vending machines has been allowed since 2004. Boiling treatment before its use is mandatory for the consumer, because the raw milk could be an important source of foodborne pathogens. This study fits into this context with the aim to evaluate the microbiological quality of 30 raw milk samples periodically collected (March 2013 to July 2013) from 3 vending machines located in Molise, a region of southern Italy. Milk samples were stored for 72 h at 4°C and then subjected to different treatments, such as boiling and microwaving, to simulate domestic handling. The results show that all the raw milk samples examined immediately after their collection were affected by high microbial loads, with values very close to or even greater than those acceptable by Italian law. The microbial populations increased during refrigeration, reaching after 72 h values of about 8.0 log cfu/mL for Pseudomonas spp., 6.5 log cfu/mL for yeasts, and up to 4.0 log cfu/mL for Enterobacteriaceae. Boiling treatment, applied after 72 h to refrigerated milk samples, caused complete decontamination, but negatively affected the nutritional quality of the milk, as demonstrated by a drastic reduction of whey proteins. The microwave treatment at 900 W for 75 s produced microbiological decontamination similar to that of boiling, preserving the content in whey proteins of milk. The microbiological characteristics of raw milk observed in this study fully justify the obligation to boil the raw milk from vending machines before consumption. However, this study also showed that domestic boiling causes a drastic reduction in the nutritional value of milk. Microwave treatment could represent a good alternative to boiling, on the condition that the process variables are standardized for safe domestic application.