bluuebunny/crossref_metadata_2025 huggingface dataset:
CIP system design and philosophy
Authors: SHARP N P B
Published: August 2007

CIP systems are now used in almost all sires and types of dairy plant. The history of this development is outlined and the major design influences are set out. The merits of the various types of CIP system in use currently are explained, as are the alternative component options now available. Consideration is given to the engineering principles and other factors that influence the cleaning efficiency of CIP systems. notably the commercial constraints which often determine design decisions. The influence of control equipment on CIP design has been significant and will continue to provide the main springboard for developments in the future.
Packaging and market design
Authors: LEONARD M
Published: August 2007

The technical and marketing characteristics needed in packaging systems to meet the needs of the distribution and retailing systems and of the consumer are described. Packages can serve a valuable purpose for advertising and conveying in formation.
Effect of commercial lipolytic enzymes on flavour development in Cheddar cheese
Authors: LAW B A , WIGMORE ANNE S
Published: August 2007

The addition of commercial lipolytic enzymes to experimental Cheddar cheese accelerated the liberation of free fatty acids during ripening. The substrate specificity of the added enzymes generally governed the chain lengths of the free fatty acids in the cheeses. None of the enzymes accelerated the formation of typical flavour in either the presence or the absence of a flavour‐enhancing proteinase, but higher addition levels produced lipolytic rancidity.
Effect of fat incorporation on properties of sterile concentrates prepared by ultrafiltration of skimmed milk
Authors: SWEETSUR A W M , MUIR D D
Published: August 2007

The preparation and properties of sterile concentrates, based on milk concentrated by ultrafiltration with added carbohydrate, are discussed. Methods are given for optimization of initial heat stability and shelf life. The new products are sweet but suffer from no apparent technical obstructions to their commercial exploitation.
Detergency and disinfection
Authors: MROZEK H
Published: August 2007

The principles to be followed to obtain satisfactory cleaning at minimum cost are set out. The importance of disinfection after cleaning, in order to minimize or prevent re‐contamination, is emphasized.
Views on the Common Agricultural Policy
Authors: PROVAN JAMES
Published: August 2007

The problem of the Common Agricultural Policy is market imbalance which, however, would probably have occurred through improvements in management and science without the existence of the CAP. A restrictive pricing policy seems to be needed to reduce this and to bring European prices more in line with those worldwide. Surpluses can also be reduced by diversification into non‐food agricultural products. Change is essential, and it is unfortunate that our government is reducing funds for research, development and extension at a time when help is especially needed.
Effect of carbon dioxide on improving the keeping quality of raw milk
Authors: RASHED M. A. , MEHANNA N. M. , MEHANNA A. S.
Published: August 2007

Fresh cows' milk samples were treated with CO2 to give a calculated CO2 content of 77mM. The treated samples as well as the control were stored at 7° and 20 ± 5°C for three days and analysed periodically. The increase in the total count as well as the counts of psychrotrophic, lactic acid and coliform bacteria during storage at 7°C was found to be inhibited by the addition of CO2. The treated samples had higher titratable acidity and lower pH values than the controls but satisfied the clot‐on‐boiling test. The keeping quality of cooled milk can therefore be improved by the addition of CO2.
Food legislation
Authors: COCKBILL C. A.
Published: August 2007

The basis of food law in the United Kingdom, which is primarily intended to protect the consumer, is described. The harmonization of legislation within the EEC, and the function of the Advisory Committees which recommend to Ministers action on food law, are considered.
Sheep dairying in Britain — a future industry
Authors: MILLS OLIVIA
Published: August 2007

The paper sets out the importance of dairy sheep in the economies of the Mediterranean Basin and points to the world shortage of ewe's milk, and the increasing demand for it, both as milk and as the products made from it, much of today's demand being met from cow's milk substitutes for original sheep products. The dairy ewe is described. Five thousand ewes, the nucleus of a new industry, are being milked in Britain today in both autumn and spring lambing flocks. Tables show the milk yields from different breeds; the composition of ewe's milk compared to that of the goat and cow; and the contribution of ewe's and cow's milk to the human daily needs of minerals and vitamins. Some of the unique qualities of ewe's milk in the making of products are discussed as well as its behaviour in the making of cheese. Its special properties in the field of food intolerances are touched on. The sheep is suggested as an alternative dairy animal.
Lactose and some of its derivatives
Authors: PRITZWALD‐STEGMANN BERND F
Published: August 2007

Lactose or milk sugar is the characteristic carbohydrate of milk and is the only sugar of animal origin. Lactose is a di‐saccharide of glucose plus galactose and is found in the three forms α‐lactose‐monohydrate, β‐lactose‐anhydride and amorphous lactose. β‐lactose in its stable and available non‐hygroscopic form is the commercial form of lactose. Lactose finds increasing applications as an excipient in pharmaceuticals, baby food, confectionery and many food recipes. Enzymatically hydrolysed lactose, especially in whey or whey derivatives, becomes increasingly interesting owing to its higher sweetness, functionality in toffee and ice cream and application in foods for people with lactose malabsorption. Lactitol, a new reduced‐calorie sweetener, is a sugar alcohol derived from lactose. Lactitol does not affect the blood glucose nor the insulin content, so it is a valuable sugar for diabetics. Lactitol is non‐cariogenic. Lactulose, a di‐saccharide of galactose and fructose, finds application in infant nutrition and medicine. The presence of lactulose in infant formula encourages the development of Bacterium bifidum in the intestinal flora. A medical use is the treatment of portal systemic encephalopathy and chronic constipation.
Yield loss of cottage cheese curd due to the formation of minor sludge: the beneficial effect of homogenization
Authors: GRANDISON A S , BROOKER B E , YOUNG P , WIGMORE ANNE S
Published: August 2007

The formation of sludge on the bottom of vats during cottage cheese manufacture was investigated. The sludge layer contained 4.23‐8.11% of the casein originally present in the vat and was probably caused by agglutinins present in the skimmed milk. Homogenization of the skimmed milk before addition of starter reduced the agglutination of bacteria during the early stages of acid development and eliminated minor sludge formation. Curd yield was increased by up to 5% and average manufacturing time was reduced by 40 min following homogenization.
Variation in the lactulose content of UHT milk during the running of a pilot and a commercial indirectly heated plant
Authors: ANDREWS GEOFFREY R
Published: August 2007

The lactulose content of UHT milk was measured during the running of a pilot and a commercial indirectly heated UHT plant. The lactulose content of milk processed in the pilot plant was found to decrease as the pressure drop across the heated sections rose. The lactulose content of the milk from the commercial plant varied little and showed no trend during an entire production shift. There was no evidence that deposit in the plants accelerated the formation of lactulose.
Conserving resources — packaging materials
Authors: NAGY G. B.
Published: August 2007

The background to food preservation and packaging developments is described. Packaging today provides the basis for many forms of shelf‐life extension, essential for modern retailing. However, packaging is often criticized on the grounds of cost and of being a waster of natural resources and energy. In this paper it is argued that packaging is necessary to protect the product from spoilage and to maintain public health — and that the packaging industry, just like any other industry, cannot exist without raw materials and energy. The total value of the UK packaging industry is £4,000 million per annum (approx £2,600 million for foods). However the total energy involved is only about 5% of the national energy consumption. The food packaging industry has always been anxious to conserve resources due to economic pressures. This has been achieved by using less packaging material, or by turning to cheaper, more abundant materials. In addition, recycling and package reuse/refilling schemes have been introduced voluntarily to save materials and energy and to protect the environment. In the near future, EEC directives will dominate packaging conservation and environmental matters.
Proteins recovered from milks heated at alkaline pH values
Authors: GRUFFERTY M B , MULVIHILL D M
Published: August 2007

Approximately 95% of available nitrogen can be precipitated from milk on adjustment to pH 4.6 after heating at 90°C × 15 minutes at its natural pH and pH 7.5, while 89% can be precipitated after heating at pH 10.0 at 60°C × 3 minutes. Non‐recovered protein includes some serum albumin, β‐lactoglobulin, α‐lactalbumin and proteose peptones. Protein isolates precipitated from milk heated at pH >7.0 are more soluble in the pH range 6.0–7.0 than those precipitated from milk heated at its natural pH. Whey proteins complex onto the casein micelles after heating milk at its natural pH, while on heating at pH >7.0 whey proteins appear to interact with k‐casein in the serum phase. When N‐ethylmaleimide is present in milk during heating the percentage protein recovered on pH 4.6 precipitation is decreased, confirming that disulphide linkage is involved in complex formation. However, addition of β‐mercaptoethanol to recovered isolates did not result in dissociation of the casein/whey protein complex, suggesting that forces other than disulphide bonding are also involved in maintaining the complex.
Opportunities for varying the composition of cows' milk*
Authors: BANKS W
Published: August 2007

At present, only two approaches for modifying the composition of bovine milk can be applied in practice: (a) changing to a breed other than the predominant Friesian and (b) dietary manipulation. Although other breeds may produce milk of high fat and protein content, the high yield of the Friesian, allied to the fact that it is an acceptable meat animal, probably ensures its continued dominance. In terms of diet, the content, yield and type of milk fat are easily susceptible to manipulation. However, the specialized diets required for this type of manipulation would probably incur extra costs, and it is not clear if the improved properties of the butter, eg, a butter having better low‐temperature spreadability, could attract a better return in the market. Protein content and yield are fairly insensitive to diet, and the consensus is that protein composition is invariant. Currently, the most sensible strategy for the dairy farmer appears to be to produce milk as cheaply as possible, and to leave it to the technologists to convert the components into a range of attractive, nutritious foodstuffs.
Milk compositional quality — opportunities for manipulation
Authors: McCRAE I , HARDING F , MUIR D D
Published: August 2007

Widespread discussion of the effects of fat in the diet and the publication of the report of the Committee on Medical Aspects of Food Policy (COMA, 1984) have created an interest in the possibilities of manipulating the fat content of milk from the dairy cow. The two most practical methods seem to be through nutrition and breeding. However, the former would be expensive and the latter would take many years. Genetic engineering techniques may produce more rapid results but would create problems of both an ethical and an economical nature.
Northern Ireland milk production — opportunities and constraints in the European Community context*
Authors: JACK W H
Published: August 2007

The paper indicates how the Northern Ireland dairy industry compared with the United Kingdom and the European Community of 10 over the last 15 years in production and the use of certain major intervention support measures. It considers changes in the manufacturing sector and the factors which affect production and highlights hidden constraints which should be capable of being overcome. It ends with a summary of areas where potential opportunities are being examined in an attempt to help the dairy industry meet the problems of the future.
Transfer of antibiotics between the udder quarters of dairy cows treated for clinical mastitis
Authors: LEONARD CATHERINE , HUNTER A C , FENLON D R
Published: August 2007

Milk samples from all quarters of 13 dairy cows, each treated with an antibiotic preparation for clinical mastitis in one quarter, were collected at each milking during treatment and for at least six milkings thereafter. After storage at —25 °C, these were tested for the presence of antibiotics. Transfer to untreated quarters was found in eight of the 13 cases studied, although in only two cases was the level in untreated quarters greater than 0.01 μ/ml. The main factor affecting transfer was found to be a history of infection in the treated quarter. This was observed in all but one case where transfer had occurred. During the period of study incorporation of milk from untreated quarters would not have raised the antibiotic level in the bulk supply to a level which would have incurred a financial penalty.
Proteins recovered from acid whey/skim milk mixtures heated at alkaline pH values
Authors: MURPHY B F , MULVIHILL D M
Published: August 2007

Skim milk and mixtures prepared by combining acid whey with skim milk at volume ratios of 2:1, 1:1, 1:2, 1:3 and 1:4 were adjusted to pH 7.5 and heated at 90°C × 15 min. Protein was isolated from these heated samples by precipitation at pH 4.6 and it was found that 65% of the whey protein was recovered in each case. Non‐recovered proteins included the proteose peptones and small quantities of β‐lactoglobulin, α‐lactalbumin and bovine serum albumin. The solubility of these isolates, which contained from 10–25% whey protein, decreased to > 95% when the whey protein exceeded ˜16%. Further characterization of the isolate, prepared from the 1:1 volume ratio of acid whey and skim milk, showed that ˜50% of the whey protein was insoluble, bound to casein and non‐functional while the other ˜50% was complexed with casein and was soluble. The addition of a reducing agent suggests that sulphydryl bonding alone is not responsible for complex formation.
Problems of funding for the independent dairy*
Authors: THOMPSON G RAYMOND
Published: August 2007

Probably the best way to illustrate the problems of funding for an independent dairy is to give a brief history of our own business which is a very small one by modern standards. Larger independent dairies will encounter quite different problems.
Modelling the relation between bacterial growth and storage temperature in pasteurized milks of varying hygienic quality
Authors: Griffiths M W , Phillips J D
Published: August 2007

The shelf‐life of pasteurized milk was mainly determined by the level of contamination with Gram‐negative psychrotrophic bacteria. The length of lag phase of the bacteria was also important, although the generation times of the naturally contaminating flora seemed to be of little relevance except for milks where the shelf‐life exceeded 10 days at 6°C. The effect of temperature on growth of the contaminants could be accurately determined by the ‘square root’ plot but the conceptual minimum temperature for growth (To) varied. The variation was related to the quality of the pasteurized milk. Effects of temperature on generation time, length of lag phase and shelf‐life were most marked at temperatures below 15°C.

The microflora of pasteurized milk varied significantly with storage temperature. At refrigeration temperatures, spoilage was mainly due to the growth of Pseudomonas spp. Enterobacteriaceae and Gram‐positive bacteria assumed greater importance in the spoilage of milks stored at temperatures above 10°C. Milks of good quality also contained Bacillus spp and this group of bacteria were not detectable in milks with short shelf‐lives.
Doorstep delivery — will it survive?*
Authors: Blake Frank
Published: August 2007

This paper examines the prospects for continued largescale doorstep milk delivery. It considers the factors behind reduced doorstep sales and notes some of the responses which the industry has made in its changing market. In contemplating the future, the paper reviews, in turn, the components of the consumer offer: the range, quality and packaging of product, the four major elements of customer service and the issue of price. It also emphasizes the essential role of the returnable container. Finally, it considers the additional need to communicate with customers. It proposes for this purpose the establishment of a joint marketing company to create and promote a national doorstep brand for milk, and to apply higher uniform standards of service.
Heat exchanger performance: y‐glutamyl transpeptidase assay as a heat treatment indicator for dairy products*
Authors: PATEL SHAILAM S. , WILBEY R ANDREW
Published: August 2007

Whole and skimmed milks were subjected to a range of high temperature short time treatments using a pilot scale plate heat exchanger. γ‐Glutamyl transpeptidase activity was assayed in the milks and the residual activities compared against the holding temperatures and total heat treatment. There was no residual activity following treatments of 78°C for 15 seconds, a total heat treatment 8.2 times more severe than that of a hold of 15 seconds at 72° C.
Quality assurance and quality monitoring of UHT processed foods*
Authors: CORDIER J L
Published: August 2007

Today, a wide range ofultra high temperature (UHT) products are commercialized and the quantity of products manufactured and sold is steadily increasing. A brief overview of the quality control of such products is given, covering sampling plans and analytical procedures applied to verify the quality of incubated packs. Attention, however, is focused on quality assurance based on the Hazard Analysis Critical Control Point system (HACCP). Different aspects such as installation, cleaning and sterilization of equipment as well as critical control points of UHT sterilization, starting from the raw materials and ending with the distribution of the finished product, are discussed.
Application of alginate particle techniques for the assessment of lethality in UHT processes*
Authors: GAZE JOY E , BROWN GAIL D
Published: August 2007

An alginate particle technique has been developed at Campden Food and Drink Research Association in order to assess the lethal effect achieved in aseptic processes. It incorporates the main food component of the product being tested with alginate and allows micro‐organisms to be immobilized in particles that are formed to shapes and sizes which simulate those in the product. Any destruction of the micro‐organism gives a quantitative indication of the total integrated lethality achieved in each particle. This technique has been tested at temperatures ranging from 60–140°C in various processing equipment, including an experimental recirculating fluid system, scraped surface heat exchangers and Ohmic heaters. The data illustrate that the technique gives a valuable assessment of lethality, which may be used as an indication or confirmation of process lethality.
BS 5750–the motorway to total quality management*
Authors: BROWN DOUGLAS
Published: August 2007

In the United Kingdom the traditional approach to quality has been superseded by a more comprehensive system of total quality management. The market leaders are convinced that their key to customer satisfaction and profitable success is quality. They have elevated it to primary position in their corporate strategy. BS 5750, the British Standard for Quality Systems, has become a vital benchmark in assessing an operation's overall approach to quality. Accredited companies have a head start not only in Europe, with a potential market of 320 million consumers, but also the w orld. Quality is the marketplace weapon for the 1990, and BS 5750 signposts the route and lays the foundations for total quality management programmes.
Product development – by accident or design?*
Authors: WILBEY R ANDREW
Published: August 2007

Product development is the response to both commercial pressures and the generation of new ideas. While accident can lead to new ideas and approaches to problems, the development work must depend on the application of expert knowledge from a range of disciplines.
PRINCIPLES OF UNIT OPERATIONS: Cheese vats
Authors: FERGUSSON P H
Published: August 2007

The following Table shows the various cheese types mentioned and considered in relation to the individual cheesemaking unit operations, and which of the latter operations are carried out in the cheese vat (Table).
Effect of yogurt cultures on the survival of bifidobacteria in fermented milks
Authors: SAMONA ASPASIA , ROBINSON R. K.
Published: August 2007

Three species of Bifidobacterium, Bif bifidum, Bif longum and Bif adolescentis were grown in reconstituted skim milk (12% total solids) either individually or in combination with one of three commercial yogurt cultures. Total colony counts were recorded for the bifidobacteria over a growth period of 24 hours and, for samples with the fermentation halted at pH 4.6, during storage at 5°C for up to 21 days. The results indicated that, while co‐inoculation with the yogurt organisms tended to suppress the growth of the bifidobacteria, subsequent storage in the presence of the yogurt cultures did not lead to any significant decline in numbers.
Factors influencing the recovery of psychrotrophic, mesophilic and thermophilic Bacillus spp from bulk raw milk
Authors: McGUIGGAN JAMES T M. , GILMOUR ARTHUR , LAWRENCE LORNA M.
Published: August 2007

Because of the wide range of physiological properties found in the genus Bacillus one of the main problems in the standard procedure for isolating these organisms from milk and dairy products is the difficulty in defining conditions which are suitable for the activation and outgrowth of all spores present. This study investigated the effects of various raw milk heat treatments, the addition of L‐alanine (a nutrient encouraging germination) to the milk after heat treatment, different incubation temperature‐time combinations and two confirmatory media on the recovery of psychrotrophic, mesophilic and thermophilic Bacillus spp occurring in raw bulked milk. There was no significant difference (p >0.05) between the confirmatory media used, ie, starch milk agar and milk plate count agar. However, it was found that heat treatment, addition of L‐alanine and the incubation period had significant effects on the recovery of the organisms from raw milk. The highest numbers of psychrotrophic and mesophilic spores were recovered after a heat treatment of 80d̀C for 10 min followed by the addition of L‐alanine to the milk at 0.1% wlv, and incubating at 6.5°C for 15 days for the former and 30d̀C for 15 days for the latter. The highest numbers of thermophilic spores were recovered from raw milk by a heat treatment of 80d̀C for 30 min, addition of L‐alanine and incubating at 55°C for 7 days.
The Biotrace method for estimating bacterial numbers in milk by bioluminescence
Authors: SUTHERLAND A D. , BELL C , LIMOND A , DEAKIN J , HUNTER E A.
Published: August 2007

A study of the hygienic quality of samples of commercial raw milks was carried out using total plate count and a reagent kit for estimating bacterial adenosine triphosphate (ATP) in milk. The method based on ATP is of greater precision. A relationship between the two counting procedures is derived and the statistical properties of computed plate counts from measurement of ATP are discussed.
Phosphatase activity levels in pasteurized goats' milk
Authors: ROSEIRO M LUÍSA de BIVAR , BARBOSA MANUELA
Published: August 2007

A study of the effect of pasteurization on goats' milk took place in order to compare the effectiveness of two pasteurization processes (low and high pasteurization) by assessing the procedure microbiologically and biochemically. The results revealed that both pasteurization processes were effective, showing microbial destruction of approximately 100%. With regard to the determination of phosphatase activity to monitor pasteurization, data in both cases were higher than the limit established for a well pasteurized milk, according to the method used. Machine milked milk showing a lower microbial content nearly achieved the standard level by batch pasteurization, 0.75 μg phenol/ml, but 2.5 μg phenol/ml by the high temperature short time (HTST) method. Phosphatase activity levels of 1.8 and 4.3 μg phenol/ml were the mean values obtained for low and high pasteurization respectively. Our results lead to the conclusion that the batch method for pasteurization of goats' milk is more efficient in terms of total bacterial count than the HTST method. Furthermore, the technique used for the determination of phosphatase activity does not seem to be adequate for pasteurization control of goats' milk, since in very rare situations were we able to attain the limit established.
In‐line viscometry in the dairy processing industry
Authors: O'CONNORI WILLIAM , McENTEE STEPHEN , O'CALLAGHAN DONAL
Published: August 2007

The viscosity of a fluid, or fluid like material, is a measure of its resistance to flow. Many foods are fluid in nature, as final products and/or during production. The viscosity of the final product is an indicator of product consistency and can determine consumer preferences. During production a suitable and reliable in‐line viscometer can help monitor the process, optimize yield, increase efficiency, reduce costs, enable a degree of automated control and improve final product consistency and quality. Whether such goals can be achieved in practice depends on many factors. This paper gives an overview of these factors.
Preliminary studies on the gelation processes of fermented and GDL‐acidified bovine and caprine milk systems
Authors: BELL IOANNA VLAHOPOULOUA E
Published: August 2007

Bovine and caprine milk gels were made by GDL‐acidification and yogurt fermentation (using ‘ropy’ and ‘non‐ropy’ starter cultures). The respective gelation processes were monitored rheologically using dynamic oscillatory testing. The bovine fermented systems produced gel structures with about half the strength of the equivalent chemically acidified gels. The fermented caprine milk systems produced gel structures some eight to 10 times weaker than the equivalent acidified systems. In all cases the caprine systems were weaker than the bovine gels despite having higher protein contents. In all cases the ‘ropy’ milk systems followed somewhat different gelation patterns and formed weaker gels than the equivalent ‘non‐ropy’ and GDL‐acidified systems. These data suggested that the starter culture material (biomass and extracellular polysaccharides) may have interfered with the protein–protein interactions during yogurt fermentation. This produced weaker gel structures, possibly by a modified gelation mechanism.
Manufacture of a feta cheese using skim milk retentate powder
Authors: BLOCK JAN DE , VILLE WILLY DE , PETIT LUC
Published: August 2007

Feta cheese was manufactured by addition of skim milk retentate powder to the cheese milk. In comparison with the reference cheese 40% of the initial milk was substituted on protein base by the powder. This substitution had little or no effect on proteolysis, lipolysis and the rheological properties of the cheese. Also sensory evaluation demonstrated that the experimental cheese was of the same quality as the reference cheese. Protein substitution proved to have some important advantages, such as a better yield and more economical cheese production. Furthermore, the skim milk retentate powder seems to have fat replacing properties.
Production of acetic and propionic acids from labneh whey by fermentation with propionibacteria
Authors: HADDADIN M S , AL‐MUHIRAT S R , BATAYNEH N , ROBINSON R K
Published: August 2007

Whey produced during the manufacture of labneh was supplemented with yeast extract (10 g/1), and then fortified with lactose, treated with β‐galactosidase or fermented with Lactobacillus helveticus, prior to inoculation with free living cells of Propionibacterium freudenreichii ssp shermanii or Propionibacterium acidipropionici or cells immobilized in aliginate beads. Under anaerobic batch conditions, fermentation of the whey with Lb helveticus followed by P acidipropionici (free cell system) for 2.5 days at 32°C gave a broth with 5.9 g/l of propionic acid and 2.4 gll of acetic acid, while immobilized cells of the same organisms gave a broth with 11.0 gll propionic acid and 3.2 g/l acetic acid over 4 days. These latter values were the maximum levels recorded with any of the treatments, and it is suggested that such yields might make recovery economically feasible in certain countries.
Putting HACCP into practice
Authors: Early R.
Published: August 2007

Food manufacturers have the responsibility to protect consumers from foodborne hazards. The Hazard Analysis Critical Control Point (HACCP) method of food safety control is accepted as the best way to assure consumer safety in the production of foods. It is a preventive approach to food safety management and, in practice, requires the completion of 14 stages which result in the development, implementation and maintenance of HACCP systems. Effective use of HACCP gives food manufacturers greater confidence regarding consumer safety, compliance with legislation and ability continuously to improve food safety control.
The role of heat exchangers in the contamination of milk with Bacillus cereus in dairy processing plants
Authors: Giffel M C Te , Beumer R R , Langeveld L P M , Rombouts F M
Published: August 2007

In the dairy industry microbiological contamination may arise from equipment used for handling or processing. In this study it was demonstrated that Bacillus cereus spores could adhere stainless steel, germinate and/or multiply in a tube heat exchanger. The levels of B cereus detect in the tubes, after 24 h at 20°C, varied from less than 1 to 2600 cm‐2. Adhering cells and/or spores were more resistant to cleaning with K500 and sodium hydroxide, determined by laboratory suspension tests and surface tests on stainless steel. This was confirmed in a field trial with a tube heat exchanger after cleaning B cereus could still be isolated from all tubes determined by swab samples of individual tubes. The identity of the isolates was checked by polymerase chain reaction/randomly amplified polymorphic DNA typing to confirm that the organisms found on the surfaces were the same as the bacteria in the ingoing milk.
Sensory properties of cheddar type cheese produced from recombined milk fat and casein fractions of bovine and ovine origin
Authors: Banks Jean M , Muir D Donald , Mcnulty David , Dreyer Insa
Published: August 2007

The sensory properties of cheddar cheese produced from ovine and bovine milk and recombined mixtures of the fat and casein from the two species have been monitored at intervals over a nine month maturation period. Seven aroma, eleven flavour and five texture attributes were evaluated by an experienced sensory panel. To facilitate interpretation of sensory data, Factor Rotation was applied to the scores obtained by Principal Component Analysis. The sensory space maps resulting from this analysis clearly indicated that cheddar aroma and flavour originate predominantly in the protein fraction of bovine milk. The protein fraction is also dominant in the development of texture. Cheese produced from ovine protein is crumbly throughout maturation, whereas that produced from bovine protein becomes more crumbly with age.
The effects of composition and some processing treatments on the rennet coagulation properties of milk
Authors: Guinee Timothy P , Gorry Claire B , O'Callaghan Donal J , O'Kennedy Brendan T , O'Brie Niamh , Fenelon Mark A
Published: August 2007

The effects of various processing parameters on the rennet coagulation properties of milk were assessed. Using low amplitude oscillation rheometry, the coagulation properties were monitored by measurement of the elastic shear modulus, G', as a function of time, t, from rennet addition; Gapos; was taken as a measure of curd firmness. The Scott‐Blair time dependency model was fitted to the experimental G' It curves for the determination of the following coagulation parameters: gel time, maximum curd firming rate, the set‐to‐cut time at 20 Pa (ie, time to reach 20 Pa) and the curd firmness after a renneting time of 2400 s. The renneting properties were enhanced by increasing the levels of milk protein and fat in the ranges 0.3–7.0% (w/w) and 0.1–10% (w/w) respectively and by two stage homogenization pressure where the first stage pressure, P1, was varied from 0 to 25 MPa and the second stage pressure, P2, was held constant at 5 MP a. The influence of these parameters, within the range investigated, in complementing the gel forming properties decreased in the following order: protein > fat > homogenization pressure. In contrast, the coagulation properties of milk were impaired by high heat treatment, the addition of a commercial microparticulated whey protein based fat substitute and by partial replacement of protein with fat.
Evaluation of test conditions during the measurement of coffee stability of instant whole milk powder
Authors: Teehan C M , Kelly P M , Devery R. , O'Toole A.
Published: August 2007

Coffee provides a harsh environment for the reconstitution of milk powder with undissolved powder being manifested as undesirable ‘floaters' or ‘sinkers’. A coffee test method was adapted to explore the behaviour of a range of industrial samples of coffee stable and coffee unstable instant whole milk powders, under varying pH, temperature and water hardness. The development and application of a simulation test suggests evidence of some stabilizing contribution by the coffee itself. High surface fat coverage, as determined by electron spectroscopy for chemical analysis, and high ionic calcium levels were associated with instances of poor coffee stability. The effects of the physicochemical characteristics of the powders on coffee stability appear to predominate when various measures were implemented, such as prior reconstitution of the powder before addition to coffee, increased agitation and use of surface active agents, which succeeded in reducing coffee sediment.
The flavour of milk and dairy products: III. Cheese: taste
Authors: Mcsweeney P L H
Published: August 2007

This is the third of a series of three papers on the flavour of milk and dairy products (see also Nursten1 and Urbach2). It deals with the taste of cheeses and so concentrates on the water soluble, non‐volatile fraction. Bitterness is the paramount concern, hydrophobic peptides being the principal culprits, but saltiness, sweetness and astringency are also considered.
Comparison of techniques for measuring the rheological properties of labneh (concentrated yogurt)
Authors: Ozer Barbaros H , Robinson Richard K , Grandison Alistair S , Bell Alan E
Published: August 2007

The effectiveness of conventional rheological dechniques (destructive) and the oscillatory dynamic test (non‐destructive) for the study of the physical properties of concentrated yogurt (labneh)was studied. Six different types of labneh (control (cloth bag method), ultrafiltrated (UF) after and ‐before fermentation, reverse osmosis (RO) ‐after and ‐before fermentation and direct reconstitution from whole milk powder) were examined. Dynamic rheological studies revealed that labneh is a viscoelastic system in which its elastic characteristic is more dominant than its viscous properties. The elastic and viscous attributes of the control labneh were significantly different from the rest of the test samples. In general, the samples with low protein content (RO‐after and ‐before fermentation and direct reconstitution labneh) produced weaker gel structures than their UF counterparts. The penetrometer and viscometer (destructive techniques) failed to reveal expected differences between the samples, and the results did not correlate with the oscillatory dynamic tests. In the light of these results, it could be suggested that dynamic studies are much more reliable than the destructive rheological techniques for the study of the physical properties of labneh.
Raw milk grading using fuzzy logic
Authors: HARRIS JOHN
Published: August 2007

In this paper the current raw milk standard specification for Zimbabwe is reviewed. The hygienic quality and the compositional quality parts of the standard are recast in fuzzy logic terms and linked with rule bases to form a structured judgment system for grading both the hygienic and compositional quality. These may also be merged to provide an overall or total quality assessment. The structured judgment system is applied to two raw milk samples from different sources. The data from the one sample yield a higher hygienic quality rating than the data from the other, but a lower compositional quality rating. A total quality rating is found for each of the two samples and compared. The structured judgment system provides a clearer and more comprehensive assessment than the currently used system, and since it embodies an expert system element there is also a conclusive opinion of the grading in the form of membership values of certain sets. It therefore goes farther than the present system as the basis for decision support.
Studies on the value of protein reducing substances in buffalo milk
Authors: SHARMA HARISH KUMAR , SINGHAL REKHA S , KULKARNI PUSHPA R
Published: August 2007

The values for protein reducing substances (PRS) of buffalo milk collected during the summer, rainy and winter seasons and subjected to thermal treatments have been determined. Analysis of model blends of reconstituted skim milk and buffalo milk for PRS values showed the suitability of the parameter as an indicator of the presence of reconstituted skim milk in both fresh and thermally treated buffalo milk.
The influence of milk pasteurization temperature and pH at curd milling on the composition, texture and maturation of reduced fat cheddar cheese
Authors: GUINEE T P , FENELON M A , MULHOLLAND E O , O'KENNEDY B T , O'BRIEN N , REVILLE W J
Published: August 2007

Reduced fat milks were pasteurized, for 15 s, at temperatures ranging from 72 to 88°C to give levels of whey protein denaturation varying from ˜ 3 to 35%. The milks were converted into reduced fat cheddar cheese (16–18% fat) in 500 litre cheese vats; the resultant cheese curds were milled at pH values of 5.75 and 5.35. Raising the milk pasteurization temperature resulted in impaired rennet coagulation properties, longer set‐to‐cut times during cheese manufacture, higher cheese moisture and moisture in the non‐fat cheese substance, lower levels of protein and calcium and lower cheese firmness. Increasing the pH at curd milling from 5.35 to 5.75 affected cheese composition and firmness, during ripening, in a manner similar to that of increasing milk pasteurization temperature. Despite their effects on cheese composition and rheology, pasteurization temperature and pH at curd milling had little influence on proteolysis or on the grading scores awarded by commercial graders during ripening over 303 days.
The isolation of salt‐tolerant lactic acid bacteria from ovine and bovine milks for use in the production of nabulsi cheese
Authors: YAMANI MOHAMMED I , AL‐NABULSI ANAS A , HADDADIN MALIK S , ROBINSON RICHARD K
Published: August 2007

Nabulsi cheese is one of the most popular white brined cheeses produced in Jordan and, traditionally, no starter cultures are employed for ripening. However, the resultant high pH means that spoilage problems arise in cheeses stored at ambient temperatures. Direct acidification or the use of commercial starter cultures have an adverse effect on flavour, but cultures derived from lactic acid bacteria isolated from local milks gave rise to cheeses that were as acceptable as the traditional products. In addition, the pHs of the cheese brines were in the range associated with stability during storage (pH 5.1–5.3), and hence it is suggested that these locally derived cultures could be employed by the industry to manufacture a nabulsi cheese from pasteurized milk that should: (a) be free from pathogens; (b) not deteriorate in‐store at ambient temperature; and (c) have a flavour profile similar to traditional nabulsi cheese.
European cheese industry: changing structure, economies of scale and implications for competitiveness
Authors: PITTS EAMONN
Published: August 2007

This paper shows the changes in the structure of the European cheese industry in the 1990s, and the implications of recent competitive behaviour. There has been a reduction in the number of plants and firms, and a significant increase in the number of firms which operate at a scale of over ten thousand tonnes of cheese per year. The extent of economies of scale in the production process is illustrated. Recent and projected investments in the industry are shown. These investments and the drive to make more efficient use of existing capacity have resulted in substantial price competition particularly for semi‐hard cheese, and probably in lower prices to farmers for milk.
Combined effects of concentrated thermophilic and mesophilic cultures and conditions of curd acidifications on the manufacture and quality of kasseri cheese
Authors: KAMINARIDES S. , PARSSCHOPOULOS N. , BERI I.
Published: August 2007

The effect offour process variables on the biological acidification of curd to be usedfor the manufacture of kasseri cheese was examined. The variables were (i) concentrated starter cultures: a thermophilic mixture of Streptococcus thermophilus and Lactobacillus delbrueckii subsp bulgar‐icus compared with a blend of Lactococcus lactis subsp lactis, Lactococcus lactis subsp cremoris and Lactobacillus casei subsp casei, and (ii) acidification temperatures: 30 and 40° C for the thermophilic cultures and 20 and 30°C for the mesophiles. The use of concentrated starter cultures enabled the cheese to be made in one day as compared with three in the traditional system usually using raw milk and no culture. The mesophilic blend combined with a lower scalding temperature (35°C) gave a higher yield than the alternative culture, and the cheeses were higher in total solids, acidity andsalt; the same cheeses were also harder and less elastic. The use of mesophilic cultures and a low acidification temperature (20° C) is recommended.
Innovation and the pursuit of excellence: a history of milk marketing in Northern Ireland 1934–1995
Authors: CHAMBERS GEORGE
Published: August 2007

This is the last article in a trilogy published by the Society to mark the replacement of thefive statutory milk marketing boards in the United Kingdom by voluntary milk marketing co‐operatives. In the August 1998 issue of the Journal (Vol 51, No 3, pp 77–85) John Empson gave a comprehensive account of the history, achievements and demise of the Milk Marketing Board in England and Wales in a changing political context common to all five boards. Dr Donald McQueen followed with an article on the three milk marketing boards in Scotland published in the November issue (Vol 51, No 4, pp 113–119). The present article concerns the long lead‐up to, and the subsequent history of, a board that was responsible for the marketing of ex‐farm milk in Northern Ireland from 1 April 1955 till 28 February 1995. The author was chief executive ofthat board from 1 October 1963 till 30 April 1988, having previously served for five years as its chief chemist. In retirement he has been delving deeply into the earlier history of the industry and recalling some of the experiences ofhis own time in milk marketing.
Incorporating whey proteins into mozzarella cheese
Authors: PUNIDADAS P. , FEIRTAG J. , TUNG M A
Published: August 2007

A study was conducted to improve the yield of cheese and make reduced fat cheese by incorporating whey proteins. Whey protein dispersions were prepared by heating whey at 95°C and pH 4.6, then removing excess serum and homogenizing part of the whey protein. Cheeses were made from standardized milk and standardized milk with homogenized and non‐homogenized protein dispersions. Cheeses were also made from standardized milk, reduced fat milk and reduced fat milk with homogenized protein. Adding whey proteins improved the yield, but lowered the retention of fat. Homogenization of whey proteins improved fat retention and yield. The dry matter increase was due to increased solids‐non‐fat. Reduced fat cheese gave lower yields, which were partially offset by adding homogenized whey proteins. Physical and sensory properties of reduced fat cheeses made with homogenized whey proteins were similar to the control.
Determination of acid phosphatase activity in heat treated milks by the Fluorophos Test System
Authors: BALCI A TÜLAY , WILBEY R ANDREW
Published: August 2007

The Fluorophos Test System® for measurement of acid phosphatase in fruit juices was used to determine the survival of acid phosphatase in heat treated cows' milk. The method was found to be applicable to milk, with reproducibility improved by use of a vortex mixer. It was sufficiently sensitive to provide a quantitative measure of the activity surviving heat treatments from 75 to 88° C for 15 seconds and would thus provide a rapid method for checking more severe heat treatments_ for instance, those used to enhance the destruction of Mycobacterium paratuberculosis.
Some aspects of the periurban dairy system in Cameroon
Authors: KAMENI A. , MBANYA N J , NFI A. , VABI M. , YONKEU S. , PINGPOH D. , MOUSSA C.
Published: August 2007

A survey to establish baseline data for future intervention in milk and dairy production in the peri‐urban areas of Garoua, Maroua and Bamenda was carried out. Dairy products are still produced in a traditional way in areas around Maroua and Garoua with milk from native zebu cattle (Red and White Fulani breeds). The important dairy products are pendidam and kindirmu, both of which are fermented milks. Naturally sour milk was found occasionally. Around Bamenda, milk is produced by herds comprising pure Holsteins, Jerseys and their crosses with local zebu cows; cross‐breeding is being intensified to increase rapidly the size of the dairy herds. Appreciable volumes of milk are produced daily, so allowing the industrial processing of fresh milk into pasteurized milk, yogurt and cheese. The potential for expansion of the dairy industry, and the possible constraints, were identified and solutions proposed.