bluuebunny/crossref_metadata_2025 huggingface dataset:
Light and copper catalysed oxidized flavours in stored milk
Authors: SCHRÖDER MONIKA J. A.
Published: August 2007

Oxidized flavour results from milk lipid oxidization which, in practice, is catalysed by either light (Λ around 450 nm) or Cu. Damaging levels of Cu may be present naturally in some milks but are usually due to contamination. Of the two defects. light‐induced flavour is today the more important by far, especially where milk is exposed to light in containers that transmit the damaging wavelengths and are, in addition, highly permeable to O2. Thus, in the UK. sterilized milk in blow‐moulded polyethylene bottles is especially at risk. The level of O2 required to produce the development of Cu‐induced oxidized flavour is negligible compared with that in milk saturated with air. In contrast, light‐induced oxidized flavour develops only after considerable O2 uptake has occurred in the milk due to ascorbic acid and other oxidations. In sterile milks exposed to fluorescent light with only the dissolved O2 present, oxidized flavour did not develop. It did. however, develop where there was an additional supply of O2 during storage. from a headspace or through an O2‐‐permeable container.
Accelerated detection of post‐heat‐treatment contamination in pasteurized double cream
Authors: PHILLIPS J. D. , GRIFFITHS M. W. , MUIR D. D.
Published: August 2007

A technique is described which enables a semi‐quantitative estimation of the extent of post‐heat‐treatment contamination of pasteurized double cream within 2 days. The method involves preincubation of the cream sample at 21° C for 25 h, after which Gram‐negative psychrotrophic bacteria are selectively counted (21° C/25 h incubation) on agar containing growth inhibitors for Gram‐positive organisms.
Post‐pasteurization contamination and shelf‐life of HTST‐pasteurized milk when filled in a Liqui‐Pak® conventional or Model 820A cartoning machine
Authors: SCHRÖDER MONIKA J. A. , BLAND MICHAEL A.
Published: August 2007

Bacterial contamination of pasteurized milk filled in a Liqui‐Pak®Model 820A cartoning machine has been examined. Compared with the conventional piston type, this new machine incorporates a number of design features to reduce or eliminate contamination during filling. The Model 820A did not normally cause post‐pasteurization contamination with psychrotrophic Gram‐negative rods, the typical spoilage organisms of conventionally filled pasteurized milk. This led to a considerable improvement in the keeping quality of the filled pasteurized milk, especially at a storage temperature of 7® C.
Subject: Milk utilization on the farm Understanding regulations ‐ the needs of the market place and the Milk Marketing Board
Authors: RAWLINSON C. S. A.
Published: August 2007

THE MMBS role and the philosophy behind the market and MMB requirements for producers wishing to become producer‐retailers, producer‐processors or producer‐manufacturers is explored. While the main conditions are described, the need for adequate planning of any retail business venture is stressed. The marketing considerations suggest it is appropriate to conduct market research and to be aware of the possible effects of competition. The MMB can provide practical help and advice in arriving at a balanced business decision.
The supplier view
Authors: GARRETT N L T
Published: August 2007

The major suppliers of goods and services to the dairy industry are identified. The commercial relationships arising in each sector of supply are considered and comparisons are made between monopolistic and competitive sources. Consideration is given to the scope of suppliers' responsibilities in terms of design, development and collaborative ventures.
A comparison of cheese yield and cheesemaking efficiency using seasonal and standardized milk
Authors: BANKS JEAN M , MUIR D D , TAMIME A Y
Published: August 2007

A study has been carried out on the efficiency of the cheesemaking process when Cheddar cheese was made from milk showing the normal seasonal trends in composition and from milk that had been standardized to a crude protein: fat ratio of 0.9. Standardization resulted in a small loss of yield from a standard volume of milk (averaged over a complete year), but this loss was compensated by an almost equal gain in the efficiency of fat retention.
A comparison of the quality of Cheddar cheese produced from seasonal and standardized milk
Authors: BANKS JEAN M , MUIR D D , TAMIME A Y
Published: August 2007

The quality of Cheddar cheese made from seasonal and standardized milk has been assessed over a 12‐month period. There was a slight consumer preference for cheese made from seasonal milk, but the difference was small and unlikely to be of commercial significance. Grade scores for cheese ‘body’ were not reflected in a consumer taste panel assessment of the quality of the mature cheese.
Isolation and identification of proteolytic psychrotrophic sporeforming bacteria from raw milk supplies at an experimental dairy in India
Authors: SHARMA J K , MALIK R K , MATHUR D K
Published: August 2007

Of 51 samples of raw milk produced at the National Dairy Research Institute, 65% were found to contain proteolytic psychrotrophic sporeforming bacilli. The protease activity of 50 isolates selected ranged from 20 to 480 units/ml. Twenty/four per cent (12) of the total isolates exhibited enzyme activity in the range 51–100 units/ml, while 20% (10) had protease activity of more than 300 units/ml. Of the 50 isolates, 36% were Bacillus cereus, 20% B. polymyxa, 14% each B. laterosporus and B. circulans. 10% B. pumilus. 4% B. subtilis and 2% were identified as B. coagulans.
Definitions of pure juices, cordials and drinks and related legal requirements
Authors: DOWNER A W E
Published: August 2007

The regulations with which the soft drinks and fruit juice industry must comply are set out and discussed. They deal with standards of composition and the names that can be used to describe the different products. The more general labelling regulations to which soft drinks must conform are also considered.
What does the food industry require of dairy ingredients?
Authors: WEST S I
Published: August 2007

Food additives and ingredients, in particular proteins, are increasingly characterized in terms of their functionality rather than their source or composition. Egg, milk and wheat proteins have been the classical functional proteins for centuries, and between them they possess a full range of functional properties. Therefore, when a new protein ingredient is to be launched on to the market, it is essential to have prior knowledge of its functionality. Included in this article is a list of the important functional properties and an indication as to which are important in different foodstuffs.
Electricity in the farm dairy: requirements, use and conservation
Authors: NORMAN ALICE J. , BOWES R. C.
Published: August 2007

Electricity is required in the farm dairy for milking and the transfer of milk, cooling and storage of milk and water heating. An audit of electricity and water use has been carried out on 12 dairy farms for two years. The results show that milk cooling consumes the largest proportion of total electricity, at 40 to 50%. Heating water for plant cleaning uses 20 to 40% of the total. Variation was found in electricity use between farms due to equipment and management differences. Seasonal variation within farms was also found. The opportunities for reducing electricity consumption in the farm dairy are outlined.
A new rapid method for the quantitative estimation of sediment in milk
Authors: PETTIPHER GRAHAM L. , RODRIGUES UBALDINA M.
Published: August 2007

A new rapid method for the quantitative estimation of sediment in milk within 20 minutes is described. The sediment was recovered from milk by filtration through 25µm pore size nylon filter cloth. After staining with malachite green the sediment on the filter was quantified by television image analysis. There was a linear relation between added sediment in the range 0 ‐ 5mg/l and the area of sediment measured by image analysis (correlation coefficient, r = 0.98). There was good agreement between the estimates of sediment in farm milks as assessed by the new method and the Minit test (r = 0.94).
Effect of incorporation of denatured whey protein on the yield and quality of Cheddar cheese
Authors: BANKS JEAN M , MUIR D D
Published: August 2007

Concentrated suspensions of a denatured protein‐fat complex were prepared by centrifugation of whey which had been heated in acid conditions. Significant improvements in cheese yield were obtained on adding the concentrate to milk for cheesemaking before renneting. A maximum increase in yield of 7% was attained in manufacturing Cheddar cheese which satisfied the legal requirements for moisture content. No consistent texture or flavour defects were evident in the cheese during the first jive months of maturation.
Market potential and trends
Authors: METCALF R L
Published: August 2007

The problems to be faced in maintaining or increasing the market for milk products in the face of changing population characteristics are considered. The economic consequences of recent EEC decisions are examined, and suggestions are made for market modification and development.
Packaging and presentation
Authors: PAINE F A
Published: August 2007

The development of individual food packs and their importance in modern retailing systems are considered. The ways in which a good pack can help sales and the factors to be taken into account in pack design are set out. The special case of packs suitable for aseptic filling of UHT milk is then examined.
Chemical composition and nutritive value of spray dried permeate powder
Authors: EL‐SALAM MOHAMED H ABD , EL‐SHIBINY SAFINAZ , MAHFOUZ MOHAMED B
Published: August 2007

Reconstituted skimmed milk (10% TS) was ultrafiltered, and the permeate was concentrated threefold by reverse osmosis and then spray dried at different temperatures (145–195° C). The drying conditions had no effect on the moisture content or the major constituents of permeate powder. The powder was mainly lactose (85%) with 6.35460% ash. A small percentage of the lactose in the permeate powder was present as a‐lactose. Sodium, potassium and citrate were present in high concentrations nearly equivalent to their average percentage in skimmed milk. The calcium, magnesium and inorganic phosphorus contents of permeate powder were also determined. The thiamine, riboflavin and niacin contents of permeate powder averaged 0.445, 0.947 and 0.729 mg/100 g respectively. The drying temperatures had no effect on the vitamin contents of the powder. The permeate powder had average Fe, Zn, Mn and Cu contents of 94.7, 21.1, 3.1 and 9.5 Fg/100 g respectively.
Aseptic filling into containers other than cartons, with special reference to sterile bulk packs
Authors: WILES R
Published: August 2007

Different industries set different standards for their aseptic operations. A standard for low acid foods k suggested. Cans and glass containers are discussed and some alternatives are mentioned. The suitability of plastics and plastics laminates for aseptic packaging k highlighted. The efficacy of the form‐filled‐seal technique k compared to that of the preformed system for aseptic operations. The main features of equipment for aseptic packaging in bulk are mentioned. Some possible future developments are predicted and novel applications for large bulk packs are suggested. Bulk aseptic packaging is in its in fancy and the current high cost of bulk packs may, in the short term, restrict their application to specialist duties.
Developments in membrane technology
Authors: MUIR D D , BANKS JEAN M
Published: August 2007

Reverse osmosis and ultrafiltration of whey are commercially successful techniques for adding value to whey. Advances in membrane performance and plant configuration have improved the efficiency of reverse osmosis for whey concentration to a level significantly greater than that of conventional evaporation. Ultrafiltration of whey k also well proven and can provide a range of protein products of diverse composition and functionality.
The future for milk products in the EEC
Authors: GORDON I. R.
Published: August 2007

The future of milk products must be set against a static European population of increasing age, already generally overfed, and a greater public emphasis on health aspects of foods. Patterns of consumption in the main countries of the EEC are examined with particular reference to the German market. It is suggested that dairy products can expand their share of the market only by replacing other foods, and that this might best be done not by the marketing of mass products but by introducing variety and segmentation of products.
Milk and cream: a review of recent market trends
Authors: HARRIS PETER G
Published: August 2007

There have been substantial changes in the market for liquid milk in the past few years. Within an overall decline in consumption there has been a marked shift to lower fat milks. The market for UHT milks is still low but is increasing. The cream market has also changed considerably, UHT cream now accounting for 20% of total sales. The reason is its long keeping quality. Fresh cream is still perceived as a quality product for use on special occasions.
Use of ultrafiltration and reverse osmosis to improve goats' milk yogurt
Authors: MARSHALL VALERIE , EL‐BAGOURY EKRAM
Published: August 2007

Acid and acetaldehyde production from yogurt starter was compared in goats' milk fortified by ultrafiltration (UF), reverse osmosis (RO) and addition of goats' milk powder. Starter activity was impaired when milk was concentrated by RO and aroma was poor in milk fortified by addition of dried milk, while yogurts made from milk concentrated by UF had good acidity and aroma. Threonine (0.1%) addition to unfortified milk and milk fortified by dried milk or UF produced yogurts with high levels of the aroma compound acetaldehyde.
The push of technology
Authors: BURGESS K J
Published: August 2007

Increases in the knowledge of milk and the behaviour of its components under different processing conditions, and developments in technology, allow the costs of production and the quality of existing products to be improved, allow new products to be produced and increase the versatility of operations. These effects are illustrated with reference to improvements in drying technology, the use of membrane concentration in cheese manufacture and the development of new buttermaking processes.
Milkfat products
Authors: RAJAH KANES K
Published: August 2007

The characteristics of butterfat are described together with modern ways of producing butter and concentrated butter or anhydrous milk fat (AMF). Possible ways of improving the properties of butter and AMF are considered. Their use in the production of recombined products is described. Finally, future possibilities in the modification of milk fat through chemical or biochemical processes are considered.
Yield maximization
Authors: PRESCOTT P W
Published: August 2007

Yield maximization depends on knowing accurately what is received into a creamery and what is produced. Good milk metering, sampling and analysis methods are needed. Investment in accurate filling systems is justified to reduce over‐filling. Perhaps the most important factors are the education, training and motivation of the workforce.
Cleaning of dairy HTST plate heat exchangers: comparison of single‐ and two‐stage procedures
Authors: TIMPERLEY D. A. , SMEULDERS C N M
Published: August 2007

A bench‐scale tubular heat exchanger and a pilot‐scale plate heat exchanger have been used to compare the effectiveness of a single‐stage with the traditional two‐stage procedure for the removal of milk deposits from heated surfaces. The use of a single‐stage detergent has been shown to produce both physically and chemically clean surfaces in half the time taken by the two‐stage, alkali‐acid procedure which did not remove completely calcium deposits.
Dairy science and technology: personal recollections
Authors: DAVIS J G
Published: August 2007

The following article is an edited version of the presentation given by Dr John Gilbert Davis, founder member of the Society, to the Reading Branch of the London, South and Eastern Section at the University of Reading on 12 March 1987.
Collaborative trial of the Penzym assay: a rapid method for the detection of β‐lactam antibiotics in milk
Authors: KNIGHT ANABEL H , SHAPTON NORAH , PRENTICE GEORGE A
Published: August 2007

The Penzym assay is a rapid enzymic method for the detection of β‐lactam antibiotics in milk in 20 minutes. Two collaborative trials of the Penzym assay were conducted between 11 laboratories using raw whole milk samples containing levels of 0.005 iu/ml, 0.015 iu/ml and 0.025 iu/ml penicillin G and were tested at 0.01 iu/ml and 0.02 iu/ml pass/fail levels. Trial 1 indicated a degree of operator dependency with a tendency to give false passes. Trial 2 confirmed the operator dependency, and both false passes and false failures were obtained. These results make the test unacceptable as a rejection test for detecting β‐lactam antibiotics in dairy laboratories. However, given the speed of testing and level of accuracy (92%), the assay may still be valuable as a screening test.
Yield of Cheddar cheese manufactured from milk concentrate by ultrafiltration
Authors: IYER M , LELIEVRE J
Published: August 2007

There are basically two methods by which the manufacture of cheese from milk concentrated by ultrafiltration can increase yields. Firstly, the procedure can increase the weight of certain water‐soluble, solids‐non‐fat components (mainly whey proteins) in the cheese. This extra solids‐non‐fat may allow extra water to be incorporated into the product without a decline in quality. Secondly, if suitable equipment can be designed, manufacture of cheese from concentrated milk can lead to a reduction in the losses of insoluble casein, fat and fines. The present study suggests that with a fivefold concentration of milk by ultrafiltration, and with the same losses of insoluble casein, fat and fines as with conventional cheesemaking, the yield of Cheddar is increased by around 4.5%. About half this increase is due to water‐soluble, solids‐non‐fat components; the remainder is due to water. With the elimination of all losses of insoluble casein and fines the gain in product is predicted to be around 6% while increases in the fat retention to 95% would bring the yield advantage to about 8%. However, it is suggested that the elimination of casein fines losses may be difficult to achieve in commercial‐scale, ultrafiltration cheesemaking equipment and that reductions in fat percentages in the whey are of little financial advantage to companies that recover whey fat.
Seasonal trends in the efficiency of recovery of milk fat and casein in cheese manufacture
Authors: BANKS JEAN M , TAMIME A Y
Published: August 2007

A study was undertaken to define the seasonal changes in the efficiency of recovery of milk fat and protein in curd during Cheddar cheese manufacture, and to examine the milk compositional factors that may contribute to these effects. Distinct seasonal trends in the efficiency of conversion of milk fat and protein to cheese were noted. Variations in the retention of milk fat in curd could be associated with seasonal changes in the casein to fat ratio of the milk.
Cleaning of dairy HTST plate heat exchangers: optimization of the single‐stage procedure
Authors: TIMPERLEY D A , SMEULDERS C N M
Published: August 2007

The influence of detergent concentration, temperature and flow rate on the time to remove milk deposits from the heated surfaces of a plate heat exchanger was studied. The results indicate that the main reduction in cleaning time was produced by small increases in the passage mean velocity of flow in the range 0.2 to 0.5 m/s. Increasing the temperature to 75 °C also resulted in substantial reductions in cleaning time. Variations in concentration, for which there was an optimum, had the least effect on cleaning time of the parameters investigated.
Transfer of radioactive contamination from milk to commercial dairy products
Authors: WILSON LINDA G , BOTTOMLEY ROBIN C , SUTTON PAUL M , SISK C HUGH
Published: August 2007

The fate of radioactive contamination resulting from fallout from the Chernobyl accident was studied during milk processing. A range of commercial dairy products was produced on a pilot/laboratory scale and the radiocaesium contents were measured by high‐resolution gamma spectrometry. The results show that the radiocaesium partitioned with the water phase and therefore butter, cream and cheese had relatively low levels of radioactivity. Ion exchange demineralization was effective in removing radiocaesium from whey. Ultrafiltration of whey resulted in a reduction of radioactivity relative to retentate solids.
Field evaluation of mechanical milk sampling devices on road tankers
Authors: FLEMING M G
Published: August 2007

Six tanker‐mounted milk sampling devices (called ‘samplers’) were evaluated by comparing the samples taken by them with those taken manually from the same milk supplies by trained operators. The samplers under test, although of different design, transferred the milk from the tanker milk line directly to the sample bottle at a point near the milk pump. The sampling rate was adjusted before each operation to ensure a fixed sampling rate from the complete supply and provide a standard sample size. When sampling for compositional quality (per cent fat) from refrigerated farm bulk milk tanks the mean difference (bias) between sampler and manual control values ranged from 0.003 to 0.018, while the standard deviation of individual differences (sampler ‐ control) ranged from 0.043 to 0.088. When sampling for hygienic quality the mean difference (bias) between sampler and control samples for the standard plate count (expressed as log10) ranged from 0.026 to 0.39, while the SD of individual differences ranged from 0.11 to 0.49.

It is concluded that with correct installation and operation the sampling devices tested are satisfactory for sampling producer milk supplies for compositional quality but not all are suited for sampling for hygienic quality. However, with minor adjustment in design or operation, in some cases performance may be improved.
Development and use of a defined strain starter system for Cheddar cheese
Authors: TIMMONS P , HURLEY M , DRINAN F , DALY C , COGAN T M
Published: August 2007

Out of 210 strains of Streptococcus cremoris and Streptococcus lactis screened, 35 were suitable for inclusion in multiple strain starters for Cheddar cheese. The use of various combinations of these 35 strains and bacteriophage‐insensitive mutants isolated from some of them as cheese starters over six seasons is described. All cheese graded well for body, texture and flavour, with <1% being downgraded due to starter failure. The system is now being used in all Cheddar cheese plants in Ireland producing ˜60,000 tonnes a year. The problems encountered in phage monitoring are also discussed.
The application of Hazard Analysis and Critical Control Point system to milk powder manufacture*
Authors: Woodhall Martin
Published: August 2007

All food manufacturers have a responsibility to have a full knowledge of the risks involved in their process, extending from raw materials through to consumption. The Hazard Analysis and Critical Control Point (HACCP) system is described as a management tool to develop preventive procedures for powder manufacture. Traditional HACCP focuses on microbiological pathogens as the hazard to the consumer. Within Dairy Crest Ltd a hazard is defined in the wider context of failure to meet product and process specifications. The paper describes the origin and development of HACCP, and gives a checklist for its successful implementation. Particular problems in implementation are discussed with reference to the author's experience. HACCP is only as effective as the management team driving it, and they must be clear as to the documentation they are setting out to produce
Routine testing of producers' milk supplies for compositional quality using randomly selected samples
Authors: CONNOLLY J. , FLEMING M G. , REID P.
Published: August 2007

In a study over a number of months, involving over 500 milk producers in three locations, and representing bulk milk collection from cans as well as mobile and stationary refrigerated bulk milk tanks, the precision of various random sampling and testing frequencies in estimating the fat, protein and lactose content of milk was evaluated. In addition, the traditional procedure of estimating the composition of milk supplies from chemically preserved composites was compared to values obtained by analysis of fresh samples. While sampling and testing every milk collection gave the most precise estimate of milk composition for each producer, it was found that for producers using refrigerated bulk milk tanks with ex‐farm collection, four random samples per month gave a precision of ±4% (or ±0.14% fat approx) for monthly fat content and ±l.2% (or ±0.04% fat approx) for annual fat content. Due to lower variability the precision for both protein and lactose estimation was much higher. The sample compositing procedure, while capable of a relatively high level of precision, did not always achieve this in practice and tended to underestimate the constituents in milk, especially protein and lactose.
Use of velocity of ultrasound to monitor gravitational separation in dispersions*
Authors: GUNNING P A. , HIBBERD D J. , HOWE A M. , ROBINS M M.
Published: August 2007

The article describes a non‐intrusive technique that is used to investigate the sedimentation/creaming of particles in a dispersion dire to gravity. The velocity of ultrasound is measured over a series of heights in the dispersion, and the data are converted to concentration profiles which are collected over a period of time. Often the method detects sedimentation/creaming at a very early stage and can therefore predict the long‐term shelf‐life of a product. The concentration profiles reveal information on the mechanisms of separation, and in certain cases give the particle size distribution and properties of the sediment/cream layer. The application of the technique to dairy products is discussed.
The development of heat‐resistant phosphatase activity in raw milk
Authors: KNIGHT ANABEL H. , FRYER SHEILA M.
Published: August 2007

The detection of phosphatase activity is used as a legal test to determine whether milk has been adequately pasteurized or whether it has been contaminated with raw milk. Occasional failures of the Milk Regulations phosphatase test were experienced by a processing dairy from stored silo milk. Trials demonstrated that the phosphatase was heat resistant and associated with a pasteurization‐sensitive, psychrotrophic organism isolated from one supply. The standard total viable count at 30°C (TVC) of the supply was satisfactory at 4.59 log cfu/ml; however, the psychrotrophic count at 7°C was much higher at 5.61 log cfu/ml. The test milk after storage produced sufficient heat‐resistant phosphatase activity to give a test failure when the psychrotrophic count reached about 7.09 log cfu/ml or greater. The occurrence of a failure was dependent on the initial numbers of psychrotophic bacteria, the amount of dilution with other milks and the storage time before processing. The psychrotrophic count of the test milk and the count of the phosphatase‐producing isolate were found to increase by approximately one log cfu/ml each day on storage at 4°C. This investigation has shown that a phosphatase failure may indicate the development of microbial phosphatase rather than a process failure. A retest after laboratory pasteurization of any sample failing the test will assist in identifying any microbially produced heat‐resistant phosphatase activity. While a TVC at 30°C will normally be expected to count most types of psychrotrophic organisms, this investigation has shown that on this occasion it did not detect specific psvchrotophic organisms which had contaminated the milk.
Prediction of the shelf‐life of pasteurized milk using dry medium culture plates (3M Petrifilm, Hygicult and Millipore Sampler)
Authors: PHILLIPS J D , GRIFFITHS M W
Published: August 2007

Petrifilm SM Plate. Hygicult and Millipore Total Count Sampler were compared with normal plate count procedures for the enumeration of bacteria after preincubation of pasteurized milk. There were good correlations between results obtained using normal plate counts and those obtained with each of the other methods. Coupling these counting methods with preincubation procedures of 21°C for 25 hours in the presence of crystal violet‐penicillin‐nisin allowed prediction of the pass rate of the recently introduced 6°C/5 day storage test for pasteurized milk. The predictive accuracy was slightly improved by the use of preincubation conditions of 15°C for 25 hours. The availability of these devices enables quality control procedures to be set up on even the smallest processing site.
Performance of a rapid ELISA for penicillin G in milk
Authors: JACKMAN R , CHESHAM J , MITCHELL S J , DYER S D
Published: August 2007

A rapid enzyme‐linked immunosorbent assay (ELISA) for the detection of penicillin G in milk at concentrations of 6 ng/ml (0.01 IU/ml) was used to screen 1651 off‐farm milk samples previously reported as containing no detectable levels of antimicrobial substances. Using a single‐well per test format and a percent inhibition cut‐off for the determination of positive/negative endpoint, 3.1% positives were obtained. Comparison with intra‐assay standards lowered the numbers of positives to 0.42%. Analysis of 170 milk samples positive for antimicrobials confirmed 92.4% as containing penicillin G using the prescribed cut‐off level and 87.6% when compared to standards. The ELISA, now available commercially in kit form, analyses between 1 and 48 samples in 15 minutes. It will detect 0.01 IU/ml to a level of confidence of 99% and 0.005 IU/ml with between 75 and 95% confidence.
Spray drying technology*
Authors: BOERSEN A C
Published: August 2007

The principles of powder production are reviewed. Special mention is made of advances in drying technology which allow the properties of powder to be tailored to specific end use.
The role of homogenization in the manufacture of halloumi and mozzarella cheese from recombined milk*
Authors: LELIEVRE JOHN , SHAKER REYAD R , TAYLOR MICHAEL W
Published: August 2007

When halloumi and mozzarella cheese are made from normal recombined milk, neither product exhibits the characteristic stretch and melt behaviour of the fresh milk cheeses. The present study demonstrates that this problem may be overcome either by using low homogenization pressures to prepare the recombined milk or by coating the fat in the recombined milk emulsion with phospholipid and homogenizing at the usual pressure. The influence of homogenization of milk on the properties of the cheese is discussed in terms of a polymer network model.
The influence of milk powder characteristics on the properties of halloumi cheese made from recombined milk*
Authors: Lelievret John , Shaker Reyad R , Taylor Michael W
Published: August 2007

The properties of halloumi made from recombined milks that had been prepared using milk powders processed by different methods were investigated. With skim milk powder, decreases in heat treatment of the liquid skim before drying were found to improve the stretch and melt properties of the cheese. In contrast, the level of solids in the skim concentrate before drying had no effect on the cheese characteristics. Ultrafiltration was also used to concentrate milk for spray drying. The resultant powder was recombined to give protein levels equivalent to that of normal milk and to that of milk concentrated fivefold. In both cases the recombined milks could be converted into high quality halloumi.
An alternative process for the manufacture of whole milk powder
Authors: Hols G , Mil P J J M Van
Published: August 2007

The traditional process of manufacturing whole milk powder has some negative aspects: high heat treatment of the milk and, owing to fouling during evaporation, loss of product. To reduce these negative aspects an alternative way of producing whole milk powder was investigated in pilot‐plant experiments. Milk was first separated into skim milk and cream and then treated further. Skim milk was subjected to a low heat treatment and concentrated by evaporation. The cream was subjected to a high heat treatment and mixed with the concentrated skim milk. The standardized whole milk concentrate was then spray dried. This process of manufacturing whole milk powder compared favourably with the traditional process with respect to product losses, the physical properties of the whole milk powder and the flavour of the reconstituted milk.
Applications of biotechnology and separation technology in dairy processing*
Authors: Donnelly William J
Published: August 2007

The potential areas of impact of biotechnology on dairy processing within the next decade are reviewed. The pace of introduction of new cultures and enzymes produced by recombinant DNA technology will be slow. There is considerable scope for extending the range of cultures and enzymes from non‐recombinant sources to improve the flavour, texture or functionality of dairy products. Developments in separation technology will permit the production of new milk protein fractions for use as food ingredients and in healthcare products. New possibilities for lactose fermentation may also arise.
Production of chhana by ultrafiltration
Authors: SACHDEVA S , REUTER H
Published: August 2007

Ultrafiltration has been successfully used in the manufacture of chhana, an Indian milk product used as a base material for making sweets. The ultrafiltration behaviour of pasteurized whole milk versus severely heated whole milk, as regards the flux, energy requirement for concentration and retention coefficients, was studied. Chhana was manufactured from ultrafiltrated retentates obtained by ultrafiltration of pasteurized whole milk and that of severely heated whole milk and the process standardized with respect to the heat treatment, concentration of coagulant and temperature and pH of coagulation. An increase of 31.4% in the yield of chhana on product basis and of 16.4% on dry matter basis was achieved. Only 4.35 kg of milk was used to produce 1 kg chhana by the ultrafiltration method against 5.7 kg of milk by the conventional method. The process offers access to easy automation and control ensuring uniformity of production on a large scale.
Dryspec2: a computer model of a two‐stage dryer
Authors: STRAATSMA J , HOUWELINGEN G VAN , MEULMAN A P , STEENBERGEN A E
Published: August 2007

Dryspec2 (DRYer System for Property and Energy Control) is an interactive computer program for use in making calculations relative to a two‐stage dryer for dairy products. The program indicates the relationship between the energy consumed by the drying process, the process parameters and the properties of the raw material and of the powder produced. To develop Dryspec2, simple model representations of both drying stages were made. Moreover, known physical relations were used to the maximum possible extent. Sorption isotherms form an essential part of the total drying model. The model can be attuned to the situation prevailing in actual practice by taking two model parameters of the first drying stage and one parameter of the second drying stage from data associated with the drying installation concerned. This gives the model a high degree of flexibility. Dryspec2 can be applied for such purposes as finding the optimum process conditions needed to produce a powder that must satisfy specific quality requirements at the lowest possible energy consumption. Dryspec2 is also suitable for use in designing or modifying a spray drying plant. Incorporation of the drying model underlying Dry spec2 into on‐line process control is currently under development.
The future of milk marketing in the United Kingdom*
Authors: DARE A R
Published: August 2007

The United Kingdom dairy market is static overall but the dynamics within each of the sectors are quite dramatic. On the milk supply side quotas have created artificial shortages, which in turn adversely impact on the UK balance of payments. In my view UK processors and farmers can only increase their income by adding value to their quota restricted milk supply or by arguing strenuously for the gradual removal of quotas. Finally this paper looks at the statutory Milk Marketing Scheme and likely changes in the way raw milk is priced in the UK.
The use of the chromogenic Limulus amoebocyte lysate assay to distinguish between ultra high temperature and in‐container sterilized milks
Authors: Mlawrence Lorna , Gilmour A.
Published: August 2007

The chromogenic Limulus amoebocyte lysate (LAL) assay may be used to distinguish between ultra high temperature (UHT) and in‐container sterilized (ICS) milks, when applied to samples which have received an additional heat treatment of 100°C for 10 minutes. This heat treatment resulted in a significant increase (p < 0.001) in the availability of lipopolysaccharides in ICS milks which did not occur in UHT milk samples. This method for distinguishing between these milk types is, however, limited to samples whose sera require extensive dilution prior to testing. This possibly reflects the calcium levels present.
Sensory evaluation of fermented milks: vocabulary development and the relations between sensory properties and composition and between acceptability and sensory properties
Authors: MUIR D DONALD , HUNTER E ANTHONY
Published: August 2007

Methodology for sensory profiling of fermented milks has been studied. A vocabulary of sensory attributes has been developed which encompasses most of the difference between samples. Principal Component Analysis, incorporating factor rotation, allowed simplification of the variability between samples to five Principal Components capable of clear interpretation. Sensory mapping was found to be a useful tool for categorizing fermented milks. The acceptability of the fermented milks was successfully modelled, by Partial Least Squares Regression, in terms of a limited number of key attributes. The model explained 88.4% of the variance. The relations between sensory attributes and the composition of the fermented milks were considered using Multiple Linear Regression. Although a number of statistically significant relations were derived they were of poor to modest value for purposes of prediction.
Anaerobic fermentation
Authors: STAFFORD D. A.
Published: August 2007

The need for proper disposal of effluents from the dairy industry is causing some strong interest in the evaluation of alternative treatment systems. Anaerobic digestion is a preferred candidate in many applications since it can be accompanied by energy recovery and also the pollution reduction needed consumes no oxygen for a high percentage biological oxygen demand/chemical oxygen demand removal. Some aerobic polishing will be required for river quality discharge. The economics of anaerobic digestion alternatives point to a return on capital expenditure–an unusual feature of a waste treatment process. The technology has been shown to be reliable and effective in full‐scale operation; the economics which have been demonstrated in several large scale operations need to be applied on a wider basis within the dairy industry.
A suggested corn sweetener blend that serves as a replacement for sucrose in a basic ice cream formula*
Authors: CONFORTI FRANK D
Published: August 2007

Vanilla ice cream (10% fat) was prepared by substituting two corn sweeteners (high fructose corn sweetener‐90: HFCS‐90, and high maltose corn sweetener: HMCS) for sucrose on a 50:50 basis at 25, 50, 75 and 100% substitution levels. Physical tests were conducted on the firmness and melting rate of the ice cream, and no significant differences (p >0.5) were found among the variations. Sensory evaluation showed that an increase in the use of corn sweetener blend caused a decline in sweetness as well as vanilla intensity with some flavour masking. The corn sweetener blend did produce a smooth texture in the ice cream when used as a 100% replacement for sucrose.
Milk production
Authors: THOMAS P C
Published: August 2007

This paper outlines some of the factors likely to influence the development of the United Kingdom dairy industry over the next decade. It considers the role of non‐European Community countries in European milk supply and utilization, the impact of changing agricultural policies and the strategies available to dairy farmers to respond to the challenges that lie ahead. It is concluded that while Eastern European countries may have long term importance as sources of low cost milk production the influences of changing agricultural policy and marketing frameworks within the EC will have a more immediate and more significant impact on UK dairy farmers. It is envisaged that medium term developments in the UK will include an increased variety in the linkages between producers and retailers and producers and manufacturers; some resurgence in farm‐based manufacturing; increased emphasis on milk compositional quality and manufacturing characteristics; continued pressure to reduce unit costs of farm production; and a movement towards lower input, less intensive systems of production.
Dairy products: technology
Authors: BANKS W
Published: August 2007

The paper deals with methods of prolonging the storage life of milk at creameries and then with technologies that have been mooted as possible alternatives to conventional heat exchangers. Postpasteurization contamination is dealt with briefly. In the case of cheese and spray drying, it is pointed out that the technology may have outreached the supporting science. The use of the microfluidizer, as opposed to the conventional valve homogenizer, is discussed. Finally, the current state of research aimed at decreasing the cholesterol level of milk is summarized.
Evaluation of the incubated plate count test for pasteurized milk
Authors: SUTHERLAND ALASTAIR D , LIMOND ANN M , MacDONALD FIONA , HIRST DAVID
Published: August 2007

Factors were examined which may influence bacterial psychrotroph counts obtained by the European Community's directed preincubation test for pasteurized milk. Studies to determine the best protocol for sampling milk indicated that the least counting error was obtained by taking at least five consecutive samples of milk. Increasing the number of replicate plates or making subsamples did not decrease counting error. When milk samples from five commercial dairies were examined over an 11 month period there was a significant difference (p < 0·001) in counts obtained over the period, but this did not seem to be a seasonal effect. The counts between dairies were not significantly different nor was the position in the pasteurization run from which the samples were taken significant. The proportion of samples which failed the test standard was 9.7% over the period. The bacterial flora isolated from plate count agar were identified; Gram­negative rods were the most common isolates. The spiral plater system was compared with the pour plate method in the preincubation test and results were found to be in close agreement, suggesting that the spiral plater could be used to improve the current official methods. Varying the time and temperature of sample preincubation was found to give significantly different results in plate counts. This suggested that preincubation conditons were critical and that variation in conditions even within the specified ranges of the test could significantly alter the bacterial psychrotroph counts obtained. Because of these results, the validity of the statutory test was questioned.
Homogenization of milk emulsions:use of microfluidizer
Authors: McCRAE CATHARINA H
Published: August 2007

The operating efficiency of a laboratory scale microfluidizer had been compared to that of a high pressure valve homogenizer using either pasteurized whole milk or recombined milk. Microfluidization was found to be a very effective method for reducing fat globule size and was only slightly affected by changes in operating pressure. The back pressure module on the microfluidizer had a marginal effect on particle size increase. As a result, the homogenization effect was always greater than that of conventional homogenization. Only very small amounts of serum protein but high levels of casein were found on fat surfaces after microfluidization. The protein load was higher than predicted on the basis of decreases in globule size. Microfluidization had little effect on the formation of fat clusters in milk. The higher protein load probably inhibited fat clustering.
Developments in the celeaning of Dairy Sterilization Plant
Authors: Timperley D. A. , Hasting A P M , de Goederen G.
Published: August 2007

The Cleaning of Dairy ultra high temperature sterilization Plant has been Studied using both single and two stage processes. Results on Pilot Scale Pland have Shown That Single stage cleaning of Such plant is feasible using a Leave Industrail detergent based on alkali (SU 556) in combination with a booster (SU 560). The analysis of the heat transfer surfaces indicated that a physically and chemically celan surface had been achieved. Thess Finding have be3en confirmed on commercial scale Plant of 12000 litres per hour capacity, leading ot significant reduction in celaing time (20­30%) in addittion to lower water water and energy consumption.
The marketing of Irish farmhouse cheese
Authors: O'CONNELL J. J. , HENCHION M. M.
Published: August 2007

Production of Irish farmhouse cheese (IFC), valued at less than £40000 in 1982, had grown to a value of over £2 million by 1993. An increase in consumer demand for speciality products has been the main factor facilitating this growth. Most of the output goes to the home market but there are some exports, mainly to the United Kingdom. Less than half of IFC producers operate on a commercial basis. Individual production is relatively low with most operators producing less than 10 tonnes per year. Producers tend to be ‘individualistic’. The industry has problems of fragmentation, variability of product quality, lack of consumer information and promotions and lack of product support. The possibility that a corporate entity could, at this stage of its development, significantly improve the industry's marketing performance was explored and the opinions of IFC producers were sought in this regard. Reactions were mixed but most consensus existed regarding the need for a corporate entity in relation to export markets and in relation to market research, promotions and trading. The opinions of distributors and various types of retailers were sought in relation to IFC and its marketing. There was general agreement that the average quality of IFC has improved substantially in recent years but improvements are required in areas such as creation of consumer awareness, packaging, some quality attributes, training and education of cheese handlers and continuity of supply. It is likely that the problems and development path of this fledgling industry are similar to those of farmhouse cheese, and indeed farmhouse food production, irrespective of geographical location.
The effect of substitution of fat by microparticulate whey protein on the quality of set‐type, natural yogurt
Authors: BARRANTES E. , TAMIME A. Y. , MUIR D. D. , SWORD A. M.
Published: August 2007

Low calorie yogurts were manufactured from reconstituted skimmed milk powder using microparticulate whey protein (Simplesse 100® in wet and dry form) as a fat substitute. They were compared with yogurt containing anhydrous milk fat (AMF 1·5%). The quality of whey protein based yogurts (at a 1·5% level of addition) was high and similar to that of the control samples containing AMF. However, serum separation was higher and firmness was lower for yogurts containing microparticulate whey protein than for those containing AMF. This difference between yogurt containing AMF and microparticulate whey protein was most marked when microparticulate whey protein (ie, wet type) was incorporated on an equivalent dry matter basis to AMF. The sensory panel identified significant differences (p<0·05) between products containing AMF and microparticulate whey protein only in terms of sour odour and perceived serum separation.