PROSPECTS FOR DAIRY PRODUCTION AND CONSUMPTION IN THE UNITED KINGDOM

Future developments in milk production and consumption until the end of the century and the gradual but steady changes in the structure of the dairy industry since the 1950s are discussed. The decline in herd numbers and corresponding increase in herd size are considered and the yield potential predicted. Hopes of increasing consumption of milk and its products on the Continent and the need to expand the market for milk and dairy products is stressed.     

A 100-Year Review: Advances in goat milk research

In the century of research chronicled between 1917 and 2017, dairy goats have gone from simply serving as surrogates to cows to serving as transgenic carriers of human enzymes. Goat milk has been an important part of human nutrition for millennia, in part because of the greater similarity of goat milk to human milk, softer curd formation, higher proportion of small milk fat globules, and different allergenic properties compared with cow milk; however, key nutritional deficiencies limit its suitability for infants. Great attention has been given not only to protein differences between goat and cow milk, but also to fat and enzyme differences, and their effect on the physical and sensory properties of goat milk and milk products. Physiological differences between the species necessitate different techniques for analysis of somatic cell counts, which are naturally higher in goat milk. The high value of goat milk throughout the world has generated a need for a variety of techniques to detect adulteration of goat milk products with cow milk. Advances in all of these areas have been largely documented in the Journal of Dairy Science (JDS), and this review summarizes such advances.     

The adulteration of food,lessons from the past,with reference to butter,margarine and fraud

The history of food adulteration and fraud and attempts at their control from the Middle Ages to date is traced for Belgium and for the UK with special reference to butter and margarine. The development of analytical procedures for the authentication of milk fat is outlined, from those based on the characterisation of fatty acids derived from milk fat in the nineteenth century to chromatographic methods in the next century and the recent rapid spectroscopic approaches. The importance of adequate surveillance programmes to reduce the incidence of food fraud is stressed.     

Arsenic concentration in water and bovine milk in Cordoba, Argentina. Preliminary results

The Chaco Pampean Plain of central Argentina constitutes one of the largest regions of high arsenic (As) groundwaters known, covering around 1 x 10(6) km2 (Smedley & Kinniburg, 2002; Farías et al. 2004). The high-As groundwaters are from Quaternary deposits of loess (mainly silt) with intermixed rhyolitic or dacitic volcanic ash (Nicolli et al. 1989, Smedley et al. 1998,2002). Early in the last century an endemic disease due to contamination of drinking water with arsenic was recognised. This disease is called HACRE (Hidroarsenicismo Crónico Regional Endémico, Chronic Endemic Regional Hydroarsenism) and is connected with a particular type of skin cancer (Astolfi et al. 1981). One of the most affected region is the province of Cordoba, where Nicolli et al. (1989) reported As concentrations that exceed the maximun level permitted for drinking water of 50 microg/l for 82% of the groundwater samples (n=60) of a study area comprising approximately 10000 km2. The southeast of Cordoba is an important milk production zone in Argentina, where dairy product consumption is up to 192 equivalent milk l/inhabitant/year. As a secretion of the mammary gland, milk can carry numerous xenobiotic substances, which constitute a technological risk factor for dairy products and above all for the health of the consumer (Licata et al. 2004). Nevertheless no studies on the incidence of high-As livestock drinking water in livestock health and its transfer to milk have been performed in Argentina. The aim of the present study was the determination of arsenic content in livestock drinking water and milk from dairy farms located in an area of high-As groundwaters, to analyse the relation between As uptake through water and its transfer to milk.     

A 100-Year Review: A century of dairy processing advancements—Pasteurization,cleaning and sanitation,and sanitary equipment design

Over the past century, advancements within the mainstream dairy foods processing industry have acted in complement with other dairy-affiliated industries to produce a human food that has few rivals with regard to safety, nutrition, and sustainability. These advancements, such as milk pasteurization, may appear commonplace in the context of a modern dairy processing plant, but some consideration of how these advancements came into being serve as a basis for considering what advancements will come to bear on the next century of processing advancements. In the year 1917, depending on where one resided, most milk was presented to the consumer through privately owned dairy animals, small local or regional dairy farms, or small urban commercial dairies with minimal, or at best nascent, processing capabilities. In 1917, much of the retail milk in the United States was packaged and sold in returnable quart-sized clear glass bottles fitted with caps of various design and composition. Some reports suggest that the cost of that quart of milk was approximately 9 cents—an estimated $2.00 in 2017 US dollars. Comparing that 1917 quart of milk to a quart of milk in 2017 suggests several differences in microbiological, compositional, and nutritional value as well as flavor characteristics. Although a more comprehensive timeline of significant processing advancements is noted in the AppendixTable A1 to this paper, we have selected 3 advancements to highlight; namely, the development of milk pasteurization, cleaning and sanitizing technologies, and sanitary specifications for processing equipment. Finally, we provide some insights into the future of milk processing and suggest areas where technological advancements may need continued or strengthened attention and development as a means of securing milk as a food of high safety and value for the next century to come.     

NUTRITIONAL ASPECTS OF MILK PRODUCTS USED FOR INFANT FEEDING

The nutritional problems in design of satisfactory food for infants and the need for more research and development is discussed. The high infant mortality in the first decade of this century is noted, while the value of heat treatment and modification of cows' milk formulations in reducing infant mortality and disease is discussed. The properties of butterfat and solids-not-fat are assessed and the functions of whey protein in human and in cows' milk evaluated. Modifications to the recommendations for composition of infant foods over the last decade with the change in the contribution of the dairy foods industry are shown.     

再制奶在干酪生产中的应用

<正> 半个世纪以来,一些鲜奶供应不足的 国家一直在使用再制奶来生产各种类型的干酪。尽管用再制奶生产干酪会受到当地政府法规的限制以及世界乳品价格波动的影响,但为了满足消费者的需求,以这种方法生产干酪在这些国家已经变得不可或缺。这个现象背后的原因是多种多样且不断变化的,如购买力增强,当地居民膳食结构的调整,以及牛奶组分分离和再制技术的进步。     

Heat stability of milk

The heat stability of milk has been the subject of a considerable amount of research for about a century. This research has been aimed mainly at understanding the effects of compositional and processing factors on heat stability and elucidating the mechanisms of protein coagulation. This paper provides an overview of the factors that influence the pH dependence of the heat stability of normal and concentrated milks. The principal heat-induced changes in the milk system that contribute to coagulation are discussed. Current knowledge of the mechanisms of heat coagulation in normal and concentrated milks is also reviewed.     

Protease stability in bovine milk under combined thermal-high hydrostatic pressure treatment

At atmospheric pressure, inactivation of protease from B. subtilis in raw milk and pasteurized milk (with and without homogenization) was studied in a temperature range of 50–80 °C. Thermal inactivation followed a first order kinetic model in the temperature range tested. Temperature dependence of the first order inactivation rate constants could be accurately described by the Arrhenius equation, allowing Ea values to be calculated. Different milk systems did not show differences in enzyme thermo stability.The combined thermal (40, 50 and 60 °C)-high hydrostatic pressure (300–450 and 600 MPa) effect on protease activity was studied. Protease was very resistant to high pressures. Pressure stability was higher in raw milk than in pasteurized milk; homogenization appeared to have a protective effect on the enzyme. The separate effects of pressure and temperature on enzyme inactivation were related to changes in L?-values and milk appearance.A very pronounced antagonistic effect between high temperature and pressure was observed, i.e. at temperatures where thermal inactivation at atmospheric pressure occurs rapidly, application of pressure up to 600 MPa exerted a protective effect.Industrial relevanceHigh hydrostatic pressure (HHP) is an emerging technology that has been successfully applied as a minimal process for a variety of foods. Although the potential for the use of HHP treatment as an alternative method to heat treatment of milk was proposed almost a century ago, the suitability of this innovative technology to extend the shelf-life of milk hinges not only on its ability to inactivate pathogenic vegetative microorganisms but also on its effectiveness to inactivate indigenous and endogenous enzymes. This work examines the combined effects of temperature, pressure and homogenization on the protease (exogenous enzyme from B. subtilis) activity in milk. Inactivation of protease could extend the shelf life of milk.     

Technical difficulties and future challenges in isolating membrane material from milk fat globules in industrial settings – A critical review

Research on the milk fat globule and surrounding membrane began a century ago. Synthesis and secretion mechanisms of milk fat globules in mammary epithelial cells are well documented, but there is still controversy about the composition of the milk fat globule membrane (MFGM). In recent years, interest in isolating MFGM material has increased because of the presumed functional potential of the proteins and lipids. However, no standardised isolation procedure exists to our knowledge. Consequently, published reports on the MFGM composition differ significantly. Various isolation methods under different conditions were applied, and contradictory effects on the MFGM structure were obtained. In addition to compositional changes, losses of MFGM material also occur under particular conditions. This makes it difficult to compare reports on the composition of the isolated MFGM material. We therefore saw a necessity to critically review past and current literature with emphasis on the reported isolation methods and respective results.     

Production of agglomerated fat-filled milk powder

The production of fat-filled milk powder as an agglomerated product and the determining factors for wettability and flow properties are discussed. The melting point of the used fat with its effect on the content of free fat in the milk powder is examined with the importance of homogenization of the concentrate emphasized. Results are considered of a modified method of agglomerating fat-filled milk powder and figures given showing the influence of inlet and outlet temperatures on milk powder, also a flow diagram of spray drying plant for production of agglomerated fat-filled milk powder. (Editor's summary)     

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.     

Experimental designs for studying the influence of the raw milk flora on cheese characteristics: a review

To study the influence of native milk flora on the flavour and texture of raw milk cheese it is necessary to produce milk without its native flora. Three procedures to eliminate native flora from milk can be discernedfrom the literature: aseptically drawn milk, heat treatment of whole milk and physical treatment of skim milk with subsequent addition of the heat treated cream. The advantages and disadvantages of these three approaches are discussed.     

非热加工技术在低或无致敏婴幼儿配方粉中应用的研究进展

牛乳营养丰富，对婴幼儿来说，是母乳较好的替代品，绝大多数婴幼儿配方粉都是基于牛乳制备的，非热加工技术在降低牛乳过敏原致敏性，减少营养成分损失等方面表现出较多优势。本文介绍了牛乳中主要过敏原的结构和B细胞表位，总结了低或无致敏婴儿配方粉的研究进展，重点阐述了非热加工技术包括高压、微波、发酵及其与酶解联合处理对乳蛋白致敏性的影响，以及在婴幼儿配方粉中的应用，并对其未来的发展做出了展望，以期能够为营养充足、适口、低或无致敏性新型婴幼儿配方粉的开发提供理论依据。     

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...     

Microbial quality and safety of milk and milk products in the 21st century

Milk and milk products have been utilized by humans for many thousands of years. With the advent of metagenomic studies, our knowledge on the microbiota of milk and milk products, especially as affected by the environment, production, and storage parameters, has increased. Milk quality depends on chemical parameters (fat and protein content and absence of inhibitory substances), as well as microbial and somatic cells counts, and affects the price of milk. The effects of hygiene and effective cooling on the spoilage microbiota have shown that proteolytic and lipolytic bacteria such as Pseudomonas or Acinetobacter spp. predominate the spoilage bacterial populations. These bacteria can produce heat‐stable proteases and lipases, which remain active after pasteurization and thus can spoil the milk during prolonged storage. Additionally, milk can become contaminated after pasteurization and therefore there is still a high demand on developing better cleaning and sanitation regimes and equipment, as well as test systems to (quantitatively) detect relevant pathogenic or spoilage microorganisms. Raw milk and raw milk cheese consumption is also increasing worldwide with the growing demand of minimally processed, sustainable, healthy, and local foods. In this context, emerging and re‐emerging pathogens once again represent a major food safety challenge. As a result of global warming, it is conceivable that not only microbiological risks but also chemical risks relating to presence of mycotoxins or plant toxins in milk will increase. Herein, we provide an overview of the major microbial hazards occurring in the 21st century.     

Equine milk proteins: Chemistry,structure and nutritional significance

Equine milk has important nutritional and therapeutic properties that can benefit the diet of the elderly, convalescent or newborn. The protein content of equine milk is lower than that of bovine milk but similar to that of human milk. In this review qualitative and quantitative differences between the caseins and whey proteins of equine, bovine and human milk are discussed. Important biological and functional properties of specific proteins are reviewed and their significance in human nutrition considered. As well as characterizing equine milk proteins in the context of human nutrition and allergology, the potential industrial exploitation of equine milk is explored. Cross-reactivity of proteins from different species is discussed in relation to the treatment of cows’ milk protein allergy. While there is some scientific basis for the special nutritional and health-beneficial properties of equine milk based on its protein composition and similarity to human milk, further research is required to fully exploit its potential in human nutrition.     

THE EFFECT OF EEC REGULATIONS ON THE MARKETING OF MILK AND MILK PRODUCTS IN THE UK

The effect on the dairy industry of membership of the EEC and the distinction between its regulations and directives as set out in the Treaty of Rome are described. Over 3,000 regulations were issued in 1974, 250 of which dealt with milk and dairy products and a list of the main regulations is given in an appendix. The advantages of price reviews more than once a year and possible seasonal milk pricing are discussed. The marketing field is described and the need for products with the greatest earning potential stressed. Developments in liquid milk markets are shown and their importance in the United Kingdom emphasized. Possible standardization in the liquid milk market, and the difficulties involved in the operation of milk marketing boards is considered. {Editor's summary).     

A 100-Year Review: Identification and genetic selection of economically important traits in dairy cattle

Over the past 100 yr, the range of traits considered for genetic selection in dairy cattle populations has progressed to meet the demands of both industry and society. At the turn of the 20th century, dairy farmers were interested in increasing milk production; however, a systematic strategy for selection was not available. Organized milk performance recording took shape, followed quickly by conformation scoring. Methodological advances in both genetic theory and statistics around the middle of the century, together with technological innovations in computing, paved the way for powerful multitrait analyses. As more sophisticated analytical techniques for traits were developed and incorporated into selection programs, production began to increase rapidly, and the wheels of genetic progress began to turn. By the end of the century, the focus of selection had moved away from being purely production oriented toward a more balanced breeding goal. This shift occurred partly due to increasing health and fertility issues and partly due to societal pressure and welfare concerns. Traits encompassing longevity, fertility, calving, health, and workability have now been integrated into selection indices. Current research focuses on fitness, health, welfare, milk quality, and environmental sustainability, underlying the concentrated emphasis on a more comprehensive breeding goal. In the future, on-farm sensors, data loggers, precision measurement techniques, and other technological aids will provide even more data for use in selection, and the difficulty will lie not in measuring phenotypes but rather in choosing which traits to select for.     

The Extracellular Protease AprX from Pseudomonas and its Spoilage Potential for UHT Milk: A Review

The negative effects of proteases produced by psychrotrophic bacteria on dairy products, especially ultra‐high‐temperature (UHT) milk, are drawing increasing attention worldwide. These proteases are especially problematic, because it is difficult to control psychrotrophic bacteria during cold storage and to inactivate their heat‐resistant proteases during dairy processing. The predominant psychrotrophic species with spoilage potential in raw milk, Pseudomonas, can produce a thermostable extracellular protease, AprX. A comprehensive understanding of AprX on the aspects of its biological properties, regulation, proteolytic potential, and its impact on UHT milk can contribute to finding effective approaches to minimize, detect, and inactivate AprX. AprX also deserves attention as a representative of all extracellular metalloproteases produced by psychrotrophic bacteria in milk. The progress of current research on AprX is summarized in this review, including a view on the gap in current understanding of this enzyme. Reducing the production and activity of AprX has considerable potential for alleviating the problems that arise from the instability of UHT milk during shelf‐life.