Origins, Growth and Potential of Dehydration ORIGINS The origins of dehydration go back into antiquity. The preservation of food by drying has been an art for centuries but it is only in the middle of the Present century that the art has been translated into terms of technology. The old methods of utilising the sun and wind to evaporate water from foodstuffs, however, still prevail in many parts of the world, and are likely to do so for years to come, for the centuries-old crafts are not easily lost, even in the age of technol In the coastal villages of West Africa, fishermen still salt down their catch and hang it in the sun to dry, making what is locally, and somewhat understandably, known as'stink fish. To Europeans, this designation is perhaps an understatement, and most would regard it as the highest built-in ptomaine poison risk imaginable. In spite of this, stink fish is highly prized by the African and, added to cassava root meal or rice, it provides a protein constituent in what would otherwise be an unbalanced carbohydrate diet The conditions of preparation would appear to Western eyes to be devoid of the simplest requirements of hygiene and process control, yet the author has never heard of any untoward effects arising from its consumption In the cattle raising territories of South America the ranchers have been sun-drying beef in a similar fashion for years. Probably this was a technique originated by the Indians, and, as recently as the early part of the present century, it was not uncommon to see a side of dried beef hanging
1 Origins, Growth and Potential of Dehydration ORIGINS The origins of dehydration go back into antiquity The preservation of food by drying has been an art for centuries but it is only in the middle of the present century that the art has been translated into terms of technology The old methods of utilising the sun and wind to evaporate water from foodstuffs, however, still prevail in many parts of the world, and are likely to do so for years to come, for the centuries-old crafts are not easily lost, even in the age of technology. In the coastal villages of West Africa, fishermen still salt down their catch and hang it in the sun to dry, making what is locally, and somewhat understandably, known as 'stink fish'. To Europeans, this designation is perhaps an understatement, and most would regard it as the highest built-in ptomaine poison risk imaginable. In spite of this, stink fish is highly prized by the African and, added to cassava mot meal or rice, it provides a protein constituent in what would otherwise be an unbalanced carbohydrate diet. The conditions of preparation would appear to Western eyes to be devoid of the simplest requirements of hygiene and process control, yet the author has never heard of any untoward effects arising from its consumption. In the cattle raising territories of South America the ranchers have been sun-drying beef in a similar fashion for years. Probably this was a technique originated by the Indians, and, as recently as the early part of the present century, it was not uncommon to see a side of dried beef hanging 5
outside the entrance to a ranch, for migrant workers and itinerants passing by to help themselves to a few slivers, to give them sustenance for their journey. It is more than possible that, for economic reasons, this custom no longer prevails but it was once quite common in the Argentine and brazil. Naturally dried fish, preserved by traditional and ancient methods, is still seen in Scandinavia and other European countries where fishing is an important industry, and it is still consumed there, as are the more scientifically processed fish products. Dried ling, or 'stock-fish,, is a common sight hanging outside the village grocer's shop in the remoter parts of Ireland away from the sea coast. It forms a regular part of the Catholic diet on fast days, in the absence of fresh fish, and, in some areas in the West of Ireland, is even preferred to the more sophisticated types of canned and frozen fish. The sun-drying of fruit also goes back for centuries and is still Practised today, Particularly where labour is cheap and abundant, and climatic conditions are favourable It will, perhaps, be demonstrated in the latter chapters that to simulate the effects of these natural forces of sun and wind can, indeed be a costly procedure, and when we think of translating the old crafts into scientific processes, then it is essential to probe very carefully into the economics of the undertaking and this is considered in some detail in Chapter 13 GROWTH The transition from craft to technology can perhaps be traced to the period during World War 1 when considerable quantities of dried vegetables and soup were shipped to the Armed Forces in Europe from the US and,to a lesser extent, from Britain. Some commercial development in dehydrated foods, particularly vegetables, had previously been achieved in the UK in the mid-nineteenth century, when dehydrated carrots and potatoes were supplied to the Royal Navy, and to troops in the Crimea. At about the same time, some early research was carried out into the manufacture of dried milk Between the two World Wars, however, little 1 to have been made in gaining domestic consumer acceptance of dehydrated foods Their value under wartime conditions was undeniable but the technology was not sufficiently advanced to make any impact on the public in general Possibly the already improved techniques in canning impeded the progress of dehydration as a popular means of conserving food Further development obviously depended on fundamental research ive a better theoretical understanding of the underlying mechanisms, and on the creation of objective methods for assessing flavour and texture
outside the entrance to a ranch, for migrant workers and itinerants passing by to help themselves to a few slivers, to give them sustenance for their joumey. It is more than possible that, for economic reasons, this custom no longer prevails but it was once quite common in the Argentine and Brazil. Naturally dried fish, preserved by traditional and ancient methods, is still seen in Scandinavia and other European countries where fishing is an important industry, and it is still consumed there, as are the more scientifically processed fish products. Dried ling, or 'stock-fish' , is a common sight hanging outside the village grocer's shop in the remoter parts of Ireland away from the sea coast. It forms a regular part of the Catholic diet on fast days, in the absence of fresh fish, and, in some areas in the West of Ireland, is even preferred to the more sophisticated types of canned and frozen fish. The sun-drying of fruit also goes back for centuries and is still practised today, particularly where labour is cheap and abundant, and climatic conditions are favourable. It will, perhaps, be demonstrated in the latter chapters that to simulate the effects of these natural forces of sun and wind can, indeed, be a costly procedure, and when we think of translating the old crafts into scientific processes, then it is essential to probe very carefully into the economics of the undertaking and this is considered in some detail in Chapter 13. GROWTH The transition from craft to technology can perhaps be traced to the period during World War 1 when considerable quantities of dried vegetables and soup were shipped to the Armed Forces in Europe from the US and, to a lesser extent, from Britain. Some commercial development in dehydrated foods, particularly vegetables, had previously been achieved in the UK in the mid-nineteenth century, when dehydrated carrots and potatoes were supplied to the Royal Navy, and to troops in the Crimea. At about the same time, some early research was carried out into the manufacture of dried milk. Between the two World Wars, however, little progress appears to have been made in gaining domestic consumer acceptance of dehydrated foods. Their value under wartime conditions was undeniable but the technology was not sufficiently advanced to make any impact on the public in general. Possibly the already improved techniques in canning impeded the progress of dehydration as a popular means of conserving food. Further development obviously depended on fundamental research to give a better theoretical understanding of the underlying mechanisms, and on the creation of objective methods for assessing flavour and texture 6
changes which are directly related to human sensory evaluation World War 2 focused more attention on the industry, as the Allies were engaged this time in a type of warfare involving transportation and deployment of men and supplies over infinitely vaster areas than in world hydrated foods enabled many of these problems of transportation and storage to be solved, in that dried vegetables, meats and soups, produced for the Armed Services'use, occupied only a fraction of the space taken up py canned and fresh food, and the weight factor was similarly reduced, p A striking example of this weight/bulk economy is provided by cabbage-a vegetable with over 90 percent water content In dehydrated form, and compressed(as was specified by the services), it weighs only one twentieth as much as raw cabbage, and occupies about one fortieth of the storage space Cabbage, carrots and potatoes figured very prominently in the dehydration programme set up by the British Ministry of Food in the early part of 1941 and, by 1943, there were several factories operating in the UK, the total production of which taken by the Ministry. Quality specifications were laid down by the Governments technical officers and close liaison was maintained at all times with the factory technicians and management. In all, some sixteen major plants and about eight smaller units came into vegetable dehydration in this period, contributing very materially to the War effort Experimental work was also carried out at this time on dried soup and dehydrated meat at a pilot plant in Northern Ireland and on dehydrated herrings in Scotland. These experiments all led eventually to commerci production of supplies for the Forces. Throughout this time, close contact ras maintained between the Ministry and those in other parts of the world who were similarly developing dehydration, Particularly in the US and Canada. In 1942 a joint Ministry of Food-US Dept of Agriculture mission was appointed by the Combined Food Board to survey the vegetable dehydration industry in America and Canada, and to assess both the current and postwar prospects. In 1943, a mission, including both British and American mem toured Africa to stimulate the dehydration industry and to form a lia with the many workers in the field. In the following year a similar mission visited India with the same aims in view and as a result of all these contacts a pool of technical information was amassed and new ideas were diffused which provided a stimulus for further valuable experimental work that, in the ensuing years, was to provide the cornerstone for a new and important industry. The transition from a wartime industry to ble commercial
changes which are directly related to human sensory evaluation. World War 2 focused more attention on the industry, as the Allies were engaged this time in a type of warfare involving transportation and deployment of men and supplies over infinitely vaster areas than in World War 1. Dehydrated foods enabled many of these problems of transportation and storage to be solved, in that dried vegetables, meats and soups, pruduced for the Armed Services' use, occupied only a fraction of the space taken up by canned and fresh food, and the weight factor was similarly reduced. A striking example of this weight/bulk economy is provided by cabbage - a vegetable with over 90 percent water content. In dehydrated form, and compressed (as was specified by the Services), it weighs only one twentieth as much as raw cabbage, and occupies about one fortieth of the storage space. Cabbage, carrots and potatoes figured very prominently in the dehydration programme set up by the British Ministry of Food in the early part of 1941 and, by 1943, there were several factories operating in the UK, the total production of which was taken by the Ministry. Quality specifications were laid down by the Government's technical officers and close liaison was maintained at all times with the factory technicians and management. In all, some sixteen major plants and about eight smaller units came into vegetable dehydration in this period, contributing very materially to the War effort. Experimental work was also carried out at this time on dried soup and dehydrated meat at a pilot plant in Northern Ireland and on dehydrated herrings in Scotland. These experiments all led eventually to commercial production of supplies for the Forces. Throughout this time, close contact was maintained between the Ministry and those in other parts of the world who were similarly developing dehydration, particularly in the US and Canada. In 1942 a joint Ministry of Food-US Dept of Agriculture mission was appointed by the Combined Food Board to survey the vegetable dehydration industry in America and Canada, and to assess both the curxent and postwar prospects. In 1943, a mission, including both British and American members, toured Africa to stimulate the dehydration industry and to form a liaison with the many workers in the field. In the following year a similar mission visited India with the same aims in view and, as a result of all these contacts, a pool of technical information was amassed and new ideas were diffused, which provided a stimulus for further valuable experimental work that, in the ensuing years, was to provide the cornerstone for a new and important industry. The transition from a wartime industry to a viable commercial 7
undertaking in peacetime was, however, slow and it was the 1950s any significant progress was made. Most of the British dehydration ceased to operate when the Services requirements diminished at the end of he War, and it was left to a handful of companies to press on with the valuable research and experimentation, barely recognising, at that difficult time, the potential which was going to open up in the ensuing two decades ontacts with enthusiastic workers in the us were renewed, and now liaison with Europe was again possible. The first major breakthrough to retail consumer acceptance of dehydrated foods was, however, to occur in America, where Potato Granules hit the market in a big way. The interest in this product was, of course, stimulated again in a military context by the hostilities in Korea, and once again the manufacturing experience gained in wartime conditions played an important part in the improvement of technology and in the upgrading of the quality of the end-product in many ways In 1954, the research workers Cording and Willard of the Engineering and Development Laboratory in Philadelphia, produced Potato Flakes by using the technique of drum drying. The resultant product was a mashed potato almost indistinguishable in taste and texture from that of a freshly processing industry, which was seeking the American consumer market o mashed potato. This was a significant step forward for the new potat Simultaneously, considerable technical advances were made in the manufacture of potato granules, on both sides of the Atlantic, and in the 1958-59 processing season in the US, 7500000Olb of granules were produced, utilising 300,000 tons of potatoes, or 3 percent of the North American crop Meat dehydration also gained some impetus this time, particularly the processing of chicken granules for soup. Chicken Noodle was one of the first varieties to be promoted and to receive wide acceptance in the retail market, which had hitherto been dominated by canned sour The success of these novel convenience packs, with the advantages of low weight, low volume and portability, opened the way for the commercial pioneers of dehydration to improve the techniques of drying and packing of a wider range of vegetables and meats, than was ever contemplated during the War, in a form suitable for and attractive to soup manufacturers The latter were not always dehydrators themselves but relied for their basic ingredients on the specialists in drying, who now recognised the potential for an ever increasing range of products. Demand now went far beyond potatoes, carrots and cabbage, and extended to the more exotic field of asparagus, mushrooms, red and green peppers, celery, leeks, tomatoes, French beans, garden peas, celeriac, courgettes, spinach and chillies
undertaking in peacetime was, however, slow and it was the 1950’s before any significant progress was made. Most of the British dehydration plants ceased to operate when the Services’ requirements diminished at the end of the War, and it was left to a handful of companies to press on with the valuable research and experimentation, barely recognising, at that difficult time, the potential which was going to open up in the ensuing two decades. Contacts with enthusiastic workers in the US were renewed, and now liaison with Europe was again possible. The first major breakthrough to retail consumer acceptance of dehydrated foods was, however, to occur in America, where Potato Granules hit the market in a big way. The interest in this product was, of course, stimulated again in a military context by the hostilities in Korea, and once again the manufacturing experience gained in wartime conditions played an important part in the improvement of technology and in the upgrading of the quality of the end-product in many ways. In 1954, the research workers Cording and Willard of the Engineering and Development Laboratory in Philadelphia, produced Potato Flakes by using the technique of drum drying. The resultant product was a mashed potato almost indistinguishable in taste and texture from that of a freshly mashed potato. This was a significant step forward for the new potato processing industry, which was seeking the American consumer market. Simultaneously, considerable technical advances were made in the manufacture of potato granules, on both sides of the Atlantic, and in the 1958-59 processing season in the US, 75,000,0001b of granules were produced, utilising 300,000 tons of potatoes, or 3 percent of the North American crop that year. Meat dehydration also gained some impetus this time, particularly the processing of chicken granules for soup. Chicken Noodle was one of the first varieties to be promoted and to receive wide acceptance in the retail market, which had hitherto been dominated by canned soups. The success of these novel convenience packs, with the advantages of low weight, low volume and portability, opened the way for the commercial pioneers of dehydration to improve the techniques of drying and packing of a wider range of vegetables and meats, than was ever contemplated during the War, in a form suitable for and attractive to soup manufacturers. The latter were not always dehydrators themselves but died for their basic ingredients on the specialists in drying, who now recognised the potential for an ever increasing range of products. Demand now went far beyond potatoes, carrots and cabbage, and extended to the more exotic field of asparagus, mushrooms, red and green peppers, celery, leeks, tomatoes, French beans, garden peas, celeriac, courgettes, spinach and chillies. 8
Dehydrated 'packet soups were undoubtedly here to stay from the 1950s onwards. The trend towards shopping in the supermarkets and chain stores,which involved carrying the purchases home, highlighted, to the housewife, the great convenience of the 40g packet against the 400g can Some of the major soup manufacturers originated from the Continent where traditional culinary skill was displayed in the formulation of soups and a considerable service was rendered to the dehydration industry by the high standard of quality maintained in this field. Promotion of these products is now worldwide, and the future potential assured if quality is maintained POTENTIAL In the mid-70s the potential for vegetable dehydration in the United Kingdom appeared to experience some set-backs, and failed to achieve some of the earlier promised forecasts This applied mainly to the demand for domestic packs of individual eas,onions and mixed vegetables Potato granules were vigorously marketed, supported by advertising in the National media, and held their share of the convenience food market better than most other products but currently there is only one major granule producer left in the UK and some 2000 tonnes are imported each year. The greater part of this tonnage comes from the Netherlands, the Federal Republic of Germany, Belgium and France. A small tonnage in 1986 came from Poland and Sweden. The USA, once a major source of imports into the UK, has shipped very little, due in the main to the weakness of sterling against the dollar since 1976, when the rate dropped from a high of $2.55 to he pound in 1971 to $1.80 in 1976. There was a temporary rally in the value of sterling against the dollarin 1979/81 but since 1976 other European origins for potato granules have developed strongly and have taken up the slack arising from the decline in home production in the last decade and American Potato granules still hold a substantial share of shelf space in the supermarkets where the domestic market is vigorously promoted but an ever increasing tonnage has now found its way into value-added products in the form of an infinite variety of potato-based snack foods, soups, sauces and garnishes, and ethnic speciality foods. Taking the straight sales of granules plus the tonnage used as a constituent of other dehydrated foods, it must be recorded that in this context the trade has expanded since 1970 Where impetus has been lost, however, is in the case of the most popular green vegetable-the'garden pea-which in the 70s looked set to compete very seriously with the frozen pea. In spite of energetic promotion
Dehydrated 'packet' soups were undoubtedly here to stay from the 1950's onwards. The trend towards shopping in the supermarkets and chain stores, which involved carrying the purchases home, highlighted, to the housewife, the great convenience of the 40g packet against the 400g can. Some of the major soup manufacturers originated from the Continent where traditional culinary skill was displayed in the formulation of soups, and a considerable service was rendered to the dehydration industry by the high standard of quality maintained in this field. Promotion of these products is now worldwide, and the future potential assured if quality is maintained. POTENTIAL In the mid-70's the potential for vegetable dehydration in the United Kingdom appeared to experience some set-backs, and failed to achieve some of the earlier promised forecasts. This applied mainly to the demand for domestic packs of individual products, such as green peas, onions and mixed vegetables. Potato granules were vigorously marketed, supported by advertising in the National media, and held their share of the convenience food market better than most other products but currently there is only one major granule producer left in the UK and some 2000 tonnes are imported each year. The greater part of this tonnage comes from the Netherlands, the Federal Republic of Germany, Belgium and France. A small tonnage in 1986 came from Poland and Sweden. The USA, once a major source of imports into the UK, has shipped very little, due in the main to the weakness of sterling against the dollar since 1976, when the rate dropped from a high of $2.55 to the pound in 1971 to $1.80 in 1976. There was a temporary rally in the value of sterling against the dollar in 1979/81 but since 1976 other European origins for potato granules have developed strongly and have taken up the slack arising from the decline in home production in the last decade and American imports. Potato granules still hold a substantial share of shelf space in the supermarkets where the domestic market is vigomusly promoted but an ever increasing tonnage has now found its way into value-added products in the form of an infinite variety of potatebased snack foods, soups, sauces and garnishes, and ethnic speciality foods. Taking the straight sales of granules plus the tonnage used as a constituent of other dehydrated foods, it must be recorded that in this context the trade has expanded since 1970. Where impetus has been lost, however, is in the case of the most popular green vegetable - the 'garden' pea - which in the 70's looked set to compete very seriously with the frozen pea. In spite of energetic promotion, 9