Journal of rhe Society of Dairy Technology Vol46, N o I February 1993

Original Papers and Proceedings

Changes in the dairy industry in the last 30 years

JOHN BIRD Alfa-Lava1 Food Engineering, Great West Road, Brentford, Middlesex TW8 9BT

Most people will accept that the food industry, in its widest sense, is a dynamic industry and has been subject to quite major disturbances in order to take advantage of changes in consumer eating habits. The dairy industry, in no less a way, has also been subject to such change. New processes and new milk-based products appear regularly. However, many of the processes we employ and the products we consume today have been around for some time.

I have been associated with the dairy industry for 30 years and have been party to, and witnessed, many changes not only in processing techniques, but also in the product range produced from these processes. The dairy industry today is very different from the industry which I joined in 1959.

I was recently asked by my company to give a 30 minute paper at a sales conference to highlight the changes during the period of time that I have been associated with the dairy industry. I was a little at a loss as to how to contract a career that spans a 30 year period into a 30 minute paper. I therefore decided, after much thought, that the only way to do justice to the subject would be to look at selected areas of the dairy industry with which I was familiar.

This paper will therefore be a nostalgic ramble down ‘Memory Lane’ of my time within the dairy industry.

PROCESSES AND PRODUCTS Let me put to you a selection of common words and phrases that we are all familiar with, and which we use in the course of our daily activities with the industry:

Self cleaning All weld pipework separators Aseptic packaging

CIP plants Automation UHT processing Low fat milks Homogenized milk Standardization Ultrafiltration Bulk milk collection Fruit yogurt

It may come as a surprise to most people to realize that the above list covers processes and products which were either not invented, or Historical review.

were in a very infant stage of development when I first joined the industry.

Liquid milk In the late 1950s and early sixties most urban areas had their own milk processing dairy which satisfied the local needs for pasteurized milk. These dairies were small by modem standards, with throughputs as low as 15 OOO litres rising, in some cases, to 60 OOO litres per day. A dairy processing in excess of 100 OOO litres of milk per day was considered a ‘large dairy’.

Rural needs were normally satisfied by the local dairy farmer who would deliver milk twice a day after morning and evening milk- ing, and usually from a churn placed on the back of a horse drawn cart. The milk would not have been subjected to any form of heat treatment, hence the need to deliver twice a day. The milk was invariably sour within 16- 18 hours of milking because the standard of hygiene on the farm was lower than today, and in addition very few homes had fridges.

Consider today’s industry where milk pro- cessing dairies can handle in excess of 500 OOO litres of milk per day, spread over a range of different liquid milk products based on fat content, packed in a variety of glass, paper and plastic containers, and can service an area covering many hundreds of square miles.

This is the change that has occurred in the liquid milk side of the industry in the last 30 years.

Dairy products In the late 1950s dairy products manufacture tended to be restricted to the commodity products, cheese, butter, milk and whey powders, with very little in the way of the ‘dessert products’ range which is available today. Government policy during this period was to purchase dairy products from the colonies and any other country which had a surplus. New Zealand had a large export of butter and cheese to the United Kingdom market, and other countries, such as Canada, also had access to our market.

Butter consumption was quite high and this product was considered part of the staple diet.

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Vol46, No I February I993 Journal of the Society of Dairy Technology

The general diet was based on a high fat intake and butter consumption per capita was roughly twice what it is today. Cream was very much a luxury product and was generally only purchased and consumed at weekends and major holidays, such as Easter and Christmas. The consumption market for liquid skim milk was non-existent, with the result that skim milk was either sold to the local pig farmer for stock feeding or processed into skim milk powder.

Transport of milk was not as well developed as it is today and the milk supply from the outlying rural areas was generally processed locally into either butter or cheese. Cheese production was very much of a ‘geographical’ product, with the cheese factories producing their local ‘territorial’ cheese in addition to cheddar. We would describe this approach today as ‘farmhouse’ production.

Distribution of dairy products was very much in its infancy and very little was seen of the supermarket type of retail operation. The local village store or corner shop would handle the sale of most dairy products while the local milkman would deliver milk and cream to the door. In rural areas the milkman was still invariably the local dairy farmer, and he would supplement his deliveries with home produced eggs and, in some cases, butter.

Milk collection The responsibility for the collection and marketing of milk direct from the farm was placed with various Milk Marketing Boards (the MMB’s), and until the early 1960s all milk was collected from farms by churn collection lorries.

Churn collection had particular problems in the summer months as the high ambient temperatures, usually coupled with a shortage of cooling water on the farms, meant that a significant proportion of the afternoon collec- tion milk was of doubtful quality when received at the dairy, and a proportion was invariably returned to the dairy farmer as unmarketable.

Bulk collection made its appearance in the early sixties, and this new system of refriger- ated bulk storage tanks on the farm coupled with collection in insulated road tankers rapidly expanded throughout the UK, which by the early seventies was totally ‘bulk collection’.

Refrigerated bulked supplies meant that a far better raw product was available to the industry, but the farmers soon realized that the refrigerated storage conditions could cover up a poor standard of on-farm hygiene, This led to some major quality problems in the manufactured products, especially long-keep- ing matured cheddar cheese, and under heavy pressure from the purchasers-in this case the major dairy companies-the MMB intro- duced a Quality Payment Scheme to reward,

or penalize, milk producers, depending on the hygienic quality of their raw milk. This scheme had the desired effect, and coupled with the payment bands for chemical compo- sition (fat % and dry matter %) the quality of the milk supply from the National Herd rapidly increased and is better today than at any time since records were introduced.

Equipment Dairy processing equipment was generally of small capacity in the late 1950s. The design of heat exchangers was not very advanced and short production runs were the norm as these units were subject to quite rapid fouling due to the high temperature differences employed between the heating water and the product. Cream separation was carried out in solid bowl separators and the advent of the self- cleaning machines in the late sixties, coupled with the new generation of plate heat exchangers, led to longer run times and larger, more efficient process plants. These two items of equipment came to the fore in the introduc- tion of the modern larger cream separation and butter plants.

Cream is no longer a weekend luxury but is consumed in large quantities not only as a liquid product but also in whipped form in fresh and frozen confection. The increase in cream consumption has gone some way to offset the recent dramatic fall-off in butter consumption.

Plant cleaning In the late fifties and early sixties hygiene standards within dairy process plants was very much ‘hit and miss’ and as cleaning-in-place (CIP) was a relatively new and generally not widely used process, the construction of most plants included all-union pipelines. These pipeline systems were taken down at night and hand cleaned. Sterilization was generally carried out by ‘steaming’ the reassembled circuits. Storage vessels, which were normally stainless steel or glass-lined horizontal tanks, were cleaned by hand. An operator would enter a vessel armed with a long handled brush and bucket of hot soapy detergent, and he would scrub the whole of the internal surfaces, finally rinsing off the detergent-soil mixture with warm water from a hose pipe. The vessel would usually be steam sterilized prior to use. The advent of reliable CIP units in the late sixties led to a new approach to pipework installation.

Glass lines, made from the new Pyrex formula, were installed in some process plants but never really found acceptance. They appeared briefly and then disappeared rapidly into oblivion. A fully welded stainless steel pipework system was the next logical step. The introduction in the late sixties of the new generation of balanced formulated detergents for the various soil debris found in dairy

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plants, brought a whole new field of expertise and the practice of plant hygiene took on a special role. Specially formulated detergents and sterilizing agents meant that sanitization of dairy plant became more reliable and reproducible.

The detergents in the late 1950s were of ‘liquid soap’ type, such as Lissapol, and alkaline types, such as caustic soda, available in either flake or pearl form. Inorganic acids and chelated formulations for use with diary equipment were in their infancy. Milk-stone build-up on the heated surfaces of milk pasteurization plant plate heat exchangers was commonplace, as usually only caustic soda solution was available for cleaning. One way to remove the milk-stone was to open up the plate pack and physically hand clean the exposed plate surfaces with an abrasive tool. This invariably caused damage to the plate surface which made subsequent milk-stone build up more likely. The neu range of chelated caustic detergents introduced in the early sixties effectively solved this particular problem.

CHANGES AND DEVELOPMENTS

In the late 1950s and early sixties pasteurized milk was restricted to three grades: Channel Island (C.I.), tuberculin tested (T.T.) and non-tuberculin tested (non-T.T.). The C.I. and T.T. grades were ‘premium’ grade milks and commanded a higher price in the market place.

In about 1964 the government, who in those days had significant influence in setting ‘ex- farm’ and ‘doorstep’ milk prices, decided that since approximately 95% of the National Herd produced a milk of T.T. grade, the justification of the T.T. premium of one old penny was no longer valid and the premium was discontinued. This move caused absolute panic in the dairy industry as there was now only one premium grade of milk and the loss of the T.T. premium effectively destroyed the profitability of the liquid milk side of the dairy industry. The industry created a new grade of milk, homogenized milk, and this was imme- diately sold at the same price as the old T.T. milk.

Profitability returned but probably at the cost of the most adverse publicity the dairy industry has had to face from the consumer. Many consumer groups attempted to suggest that the premium for homogenized milk was not justifiable on the same health grounds as the T.T. premium-which was of course quite correct, there being little or no real health benefit-and that the industry was holding its customers to ransom! The spokesmen for the dairy industry had great difficulty in convinc- ing the public of the virtue of homogenized milk and the furore took a considerable time to settle down.

The awareness of the consumer and the general trend towards a low fat diet led to the introduction of standardized milks in the late seventies and early eighties. Many liquid milk dairies, as well as cream and other multi- product factories, have invested in On-line Standardization Systems to produce low fat and skim milks for liquid consumption. In addition, a whole range of various fat% milks and fat-dry matter ratio standardized milks for use as raw materials in other products, such as ice cream formulations, concentrated milks and cheese, are produced. Liquid milk dairies are no longer single product factories but have to be capable of a flexible approach.

UHT A new invention-UHT (ultra high tempera- ture) milk-with aseptic packaging, made its debut in the late sixties and was hailed as the new process to revolutionize the milk distribu- tion system.

We are still waiting! Initially, sales were encouraging as the

public wanted to try this new milk with virtually unlimited shelf-life, compared to the three to five day shelf-life of pasteurized milk. However, the sale of UHT milks soon returned to a level that they still hold today. The experience in other parts of the world is very similar. The UHT market in the United States has been stagnant despite a massive sales and advertising campaign.

The advent of the UHT plant coincided with the introduction of small ‘spot’ automa- tion systems for local control of small plants such as UHT and CIP units. This automation was mainly ‘step’ function with some analogue capability. The pressure to look seriously at automation of total plants came in the 1970s and rode on the back of the government relaxation of the rules setting the ‘doorstep’ price for milk. The industry now had to sell pasteurized milk for what it could get and as the distribution side of the industry became more competitive, the pressure on margins forced the industry to look closely at its processing and distribution costs. Labour was the largest cost after the basic raw materials, milk, and the advantages of automation in reducing labour and in allowing managment more control of the process became apparent. High capital investment in fully automated liquid milk dairies and manufacturing factor- ies was one of the main areas of investment activity in the industry over the last 15-20 years.

Yogurt The liquid milk side is not the only area where innovation has taken place. From the late fifties onwards fermented dairy products, based on yogurt and other yogurt-related products, started to appear.

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Vol46, No I February 1993 Journal of rhe Society of Dairy Technology

Initially, yogurt was a set-curd product available in natural or flavoured varieties, the flavoured varieties being generally restricted to the ‘red’ fruits such as raspberry, straw- berry and cherry. My first position in the industry was in a small yogurt factory in the north of England and the weekly production was approximately 1500 gallons set-curd yogurt packed in 4 fluid ounce pots (we used the ‘understandable’ system of meaurement in those days). This production level was approximately 7% of the UK consumption in 1961.

Fruit yogurt made an appearance in 1967- 68 and was introduced from Switzerland. Contrary to popular opinion, the product was launched first by an independent dairy com- pany on the south coast-Chichester Dair- ies-who were in the market slightly ahead of Express Dairies with the Ski label. When I joined Chichester Dairies in 1970 this whole range of products was under development and I was privileged to be involved in the evol- ution of this rapidly growing product area.

Cottage cheese was introduced into the UK market at about the same time as yogurt and these two products formed the core of what came to be referred to as the ‘chilled product’ range. Significant development of this range, spearheaded by Eden Vale, St Ivel, larger independent companies and the major super- market chains, has taken place over the last 20 years, and this area now represents a signifi- cant and still growing segment of the industry. To service this segment of the market a new distribution system based on refrigerated box lorries was created and these vehicles, in distinctive company livery, are commonplace on the roads today.

THE PURPLE PATCH

The UK dairy industry went through its ‘purple patch’ in the 10-15 years after the UK joined the European Economic Community (EEC). The Common Agricultural Policy encouraged the EEC farming community to produce more and more milk, with the object of being completely self sufficient in milk and dairy products manufacture, and to reduce the reliance of the UK, and to a lesser extent the EEC, on imports from our traditional sup- pliers such as New Zealand.

Special arrangements were made for some of these countries to be given access to the normally closed EEC market and, in the case of New Zealand, these arrangements still hold today. As with most cases of tampering with market forces, the EEC went from being a nett importer, through self-sufficiency, to a surplus of milk production.

Massive investment in the UK in butter and skim milk powder manufacturing plants was led by the Dairy Crest organization, and the surplus milk was manufactured into the ‘sump’ products of butter and skim milk

powder and put into Intervention Board store. The Intervention Board was a novel device set up by the EEC to give the appearance of normality within the industry while paying out vast sums of taxpayers’ money to buy up surplus milk production in the form of butter and skim milk powder, which no one wanted.

Milk quotas The world market lacked the capacity for these excess products and artificial markets were created by the EEC by selling off subsidized butter and skim milk powder to the Eastern block countries and emergent nations, many of whom did not have a high fat diet. Eventually, even the slow reacting EEC realized that this situation could not go on indefinitely, and in 1984 milk production quotas were introduced across the EEC, which in turn would limit the production of the sump products. UK milk production was cut by 15% -a loss of milk production capa- city of 1 litre in every 7, an immense and punitive amount. This decimated the UK dairy farming industry and led many dairy farmers to leave milk production; in addition, it led to the demise of a large proportion of the dedicated butter-powder process plants. In my 10 years with Alfa-Lava1 one complete butter factory was sold, installed and commis- sioned, shutdown, mothballed and finally dismantled. The factory today, physically, no longer exists.

The situation in 1992 was that milk supply and demand was almost in balance in the UK but was still out of balance in the rest of the EEC. A further round of quotas is expected and figures of 7-9% reduction in UK milk production capacity have been suggested. At this level of reduction the UK will be thrown into a short-fall situation and will have to balance this by importation of milk from within the Community.

French milk on your cornflakes! This is a most absurd situation and is based

purely on EEC political expediency. How else do you explain the restrictions placed on the UK, which is probably the best grass growing area in the whole of the EEC?

Good council is expected to prevail and the UK share of the quota reduction is expected to be no more than 4-5%. The liquid side of the industry will still have first call on supplies, but the reduction will put pressure on the manufacturing side and quotas at this level will render it very difficult for the industry to expand its share of the UK chilled product market.

Supermarkets The dairy industry ‘sold its soul’ to the supermarket chains in the mid-1970s and the buying muscle that these organizations have has led to intense pressure on the profitability

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of the industry. The chase for increased margins led to heavy capital investment in the cheese sector of the industry. In the early nineties Dairy Crest Foods invested in a major cheddar cheese factory at Davidstow, Corn- wall, and as a result of the high level of automation within the plant design, coupled with the low manning levels, this combination made possible the production of low unit-cost, high quality cheddar cheese. Incidentally, this was the first ‘major’ cheese block-former system to be installed in the UK, which is quite remarkable when one considers that the UK is the home of the block-former. New Zealand cheddar cheese was produced almost totally on block-former systems by the time of the Davidstow project.

The Davidstow investment created a knock-on effect, with subsequent investment in at least five other major cheddar cheese plants within different dairy companies over the subsequent six to eight years.

Desserts The emergence of a dessert market on the Continent for new and innovative dairy products has led to the introduction of the new and versatile membrane technology, which not only allows for a flexible approach to soft cheese manufacture, but also greatly

enhances the yield of these products by encapsulating the whey proteins normally lost in the cheese manufacturing process. The use of ultrafiltration technology has revolution- ized the manufacture of a whole range of dessert products and soft cheeses such as quarg and fromage frais, and is seen in many quarters as the ‘process of the future’.

The consumer has become more aware of continental dessert products as they now meet these on their foreign holidays. The industry will have to be versatile and pro-active if we are to control our own market. 1992 opened up our market much more to the other EEC member states. What our industry must not forget is that their market is open to the UK dairy industry. The UK dairy industry has the opportunity to be more international in its outlook and we should all reap the benefit.

THE BRIGHT PATCH

The dairy industry I knew 30 years ago has long gone, and it has been replaced by a highly efficient, flexible and reactive industry well able to produce high quality milks and innov- ative dairy products which give the consumer a wide variety of choice and value.

The UK dairy industry has changed for the better and I am privileged to have been part of it.

Industrial scale production of Moroccan samn

M FAID’, J P LARPENT2, Y ADRIAN3, J L CHABARD4, A TANTAOUI-ELARAKI’ and A EL MARRAKCHI’

Departement de Microbiologie Alimentaire et Biotechnologie, IAV Hassan I1 BP 6202 Rabat-instituts, Morocco; * UniversitC Blaise Pascal Laboratoire de Microbiologie, Clermont-Ferrand, France; Laiterie du Chalet Route de Ricros, Domerat, France; Laboratoire de Chimie Analytique, FacultC de Pharmacie, Clermont-Ferrand, France

Pilot scale samn production was carried out in a dairy factory. Pasteurized butter, produced by concentrating and maturing cream, was used for samn preparation. Two batches of 100 units of 10 kg each were prepared with the use of a lipase (microbial lipase (EC.3.1.1.3) type VII from Candida zeylanoides). The trials were monitored by free fatty acid (FFA) determinations using the gas chromatograph-mass spectrometer system, and parallel sensory evaluations were carried out on the same samples. Results showed that high proportions of the prepared units were assessed as samn by the tasters. These units exhibited FFA profiles approaching those of traditional samn.

INTRODUCTION Product development - by accident or design? This was the subject of a report on food product development by Wilbey (1990). The practice of converting milk into dairy products may constitute the main methods for preserv- ing the nutritive value of milk over long periods (eg, ripened cheese) or for enhancing its organoleptic quality (eg, fermented milks).

Original paper. &mes,,,,ndene to M Faid.

All the procedures date back several centuries and have been improved by modern tech- nology. Several products are modelled on the protein portion of milk but, so far, there has been less concern about the transfor- mation of butter to products that are more enjoyable to consumers and more beneficial for the dairy industry by alleviating overpro- duction of butter in some countries, par-

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