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Article
Publication date: 6 September 2011

Enver Baris Bingol, Omer Cetin and Karlo Muratoglu

The purpose of this study is to investigate the effect of lemon juice on the survival of Salmonella Enteritidis and Escherichia coli in cig kofte (raw meatball).

Abstract

Purpose

The purpose of this study is to investigate the effect of lemon juice on the survival of Salmonella Enteritidis and Escherichia coli in cig kofte (raw meatball).

Design/methodology/approach

Cig kofte samples were inoculated one by one with both bacteria at high inoculum levels and were treated with different doses of fresh lemon juice (2, 5, 10 and 15 ml) for 10 seconds, 30 seconds, and 1, 5, 15, 30 and 60 minutes.

Findings

Treatments of lemon juice for different exposure times caused reduction ranging between 0.1 and 1.7 log CFU/g for Salmonella Enteritidis and 0.1 and 2.1 log CFU/g for E.coli. Results showed that lemon juice caused slight decrease in Salmonella Enteritidis and E.coli as an immediate inhibitor, but this effect increased with concentration and time.

Originality/value

This is a research study to provide information on the effectiveness of lemon juice which is squeezed generally before eating cig kofte, on the presence of the surface flora to strengthen the hygienic quality of the product. Inactivation effect of lemon juice on Salmonella Enteritidis and E.coli may give a practical and easy way of providing food safety for cig kofte.

Details

British Food Journal, vol. 113 no. 9
Type: Research Article
ISSN: 0007-070X

Keywords

Article
Publication date: 1 December 1937

Mr. H H. Bagnall, B.Sc., F.I.C., Public Analyst for the City of Birmingham, comments in his annual report on the work done at the City laboratory and on the still apparent…

Abstract

Mr. H H. Bagnall, B.Sc., F.I.C., Public Analyst for the City of Birmingham, comments in his annual report on the work done at the City laboratory and on the still apparent need for standards and definitions of food, and of legislation to enforce their application in manufacture or in shops. Of the 5,472 samples taken in the city under the Sale of Food and Drugs Acts 4 per cent. were found to be adulterated, but he observes that misdescription of articles of food is much more common than actual adulteration. The number of samples taken during the year was larger, and the variety greater, than in any previous year. About 140 different varieties of foods and drugs were examined, and few, if any, foods were not sampled. It was reassuring to learn that the Minister of Health was considering the introduction of legislation on the lines of the recommendations submitted in 1934 by the Departmental Committee which enquired into the working of the law as to the composition and description of articles of food other than milk. Ice‐cream was a case in point. In fifty‐one samples taken, the fat content varied between less than 2 per cent. and 19 per cent. Roughly, the samples were of two classes. Those containing less than 4 per cent. were bought mainly from carts in the streets of parks, and were probably the products of smaller makers; those with more than 8 per cent. were manufactured on a large scale by a few well‐known firms. “It is obvious something is wrong here,” Mr. Bagnall reports. “Apart from any question of price, ice cream is, or should be, a valuable article of food, and the purchaser should have some means of knowing what to expect when he asks for it. At the moment he may get a substance which approximates to frozen custard (not made with eggs !) or he may get a really first‐class product containing a considerable amount of cream. The position is similar with respect to a number of other products, particularly compounded articles; and the beneficial effect of legislation in such matters is clearly shown in the case of condensed and dried milks. This kind of governmental interference with manufacture used to be thought of as grandmotherly legislation; but, when one remembers the sort of statement, bearing no relation to the contents, that used to appear on tins of condensed milk, one cannot but feel that there may be some virtue in these departures from laisser‐faire methods. At any rate, no one would wish to return to the old haphazard days when condensed milk was simply what the manufacturers chose to make it. It is curious that the law is far more careful that the composition of feeding stuffs sold for the use of cattle should be made known to the purchaser than that articles sold for human consumption should be sold under a guarantee of quality. If I buy, say, cotton cake for feeding cows, the vendor is bound to give me an invoice stating the amounts of oil, protein and fibre contained in it, and severe penalties are entailed if false statements are made. If I buy an infant's food, however, there is no compulsion on the part of the maker to give particulars regarding its composition. In fact, the label may contain statements entirely at variance with the analysis, but which, nevertheless, are of too vague a character to become the subjects of police court proceedings. It is surely as important that the mother of a child should know something of the composition of the food she uses as that a farmer should know the food value of his cattle cakes, and it is to be hoped that legislation on such matters may not be unduly delayed. The misdescription of articles of food is a much more common thing than adulteration. Under modern conditions of inspection and sampling, it simply does not pay manufacturers and retailers to risk the cruder forms of adulteration and substitution, but the wide use of advertising as an aid to sales, often leads to the use of exaggerated statements regarding the quality and food value of articles of diet. We are all familiar with the extraordinary claims put forward on behalf of particular foods of well‐known composition which seek to show that they possess unique properties not shared by other similar foods. It is often impossible for the food analyst to check such statements, and the public is deceived into thinking that a superior article is being obtained. Often it is only in the advertisements relating to the article in question that one finds these exaggerated statements, and when a tin or packet is bought it is found that the label gives a much milder description of the contents. Under the present law only statements appearing on the label can be made the subject of legal proceedings. It is desirable that false claims appearing in advertisements should also be brought within the scope of food and drug legislation.” During the year a number of samples of pasteurised milk were examined by the “phosphatase test.” Of 112 samples, fifty‐eight were efficiently pasteurised; in thirty‐six cases some technical error had occurred during the process, such as imperfect temperature or time control, or a small admission of raw milk; and in the remaining eighteen cases there was evidence of gross negligence. The samples were taken at selected times and places thought likely to yield abnormal figures, so that too much weight should not be given to the fact that about 48 per cent. of the samples did not pass the test.”

Details

British Food Journal, vol. 39 no. 12
Type: Research Article
ISSN: 0007-070X

Article
Publication date: 14 November 2016

Satish Chandra Kushwaha and Pradyuman Kumar

The purpose of this study is to look at the application of ellagitannin (ET) powder in sharbet (sugar syrup-based drink) as an additive to produce a polyphenol-enriched…

Abstract

Purpose

The purpose of this study is to look at the application of ellagitannin (ET) powder in sharbet (sugar syrup-based drink) as an additive to produce a polyphenol-enriched drink. ETs are important polyphenols extracted from pomegranate peel (an underutilized juice industry waste). ETs are known for many functional properties such as antioxidative, antibacterial and coloring agent. Naturally, sharbet lacks in polyphenol content; hence, there is a large scope to enhance the functional property of sharbet by addition of ellagitannin powder (ETP) as an additive.

Design/methodology/approach

ETP at different concentrations (2, 10, 20, 30, 40 and 50 mg/100 ml sharbet) was applied in plain sharbet (EPS) and lemon-flavored sharbet (ELS). Each concentration of both types of sharbet was analyzed for physicochemical parameters and sensory attributes by sensory panel. Data were analyzed by using statistical tools (t-test, ANOVA, PCA and graphs) and finding the acceptability of ETP application in sharbet.

Findings

Each concentration of both sharbets was analyzed for chemical attributes, i.e. color (L, a, b) ranges (65.81-51.33, −0.24-0.24, −1.57-2.06, respectively), pH (6.30-3.95), titrable acidity as citric acid (0.01-0.1 per cent), total soluble solids (14.7-14.9 per cent), antioxidant activity as DPPH (12.6-71.6 per cent in EPS and 15.5-75.3 per cent in ELS) and sensory analysis (on Hedonic Scale) for sensory attributes, i.e. color, odor, taste and overall acceptability by a sensory panel (n = 24) of food technologists. Principal component analysis and sensory evaluation score have revealed that sharbet-flavored with lemon extract was liked more in comparison to plain sharbet. ELS containing 30 and 40 mg ETP per 100 ml sharbet was showed to have the highest acceptability index (92.13 and 91.67 per cent) in terms of overall acceptability by sensory panel. It is evident that the addition of ET in polyphenol-deficient beverages could be a market potential toward production of neutraceutical beverages which have antioxidative effects, good taste and are widely accepted.

Originality/value

In view of the neutraceutical food development, ETs could be a major polyphenolic component to fulfill the human health requirement. This research can be helpful for commercialization of ETs by the beverage industry.

Details

Nutrition & Food Science, vol. 46 no. 6
Type: Research Article
ISSN: 0034-6659

Keywords

Article
Publication date: 1 February 1983

Although universally recognised as the source of the best thirst‐quencher of all, the useful lime is a fruit that tends to be much neglected in most European countries…

Abstract

Although universally recognised as the source of the best thirst‐quencher of all, the useful lime is a fruit that tends to be much neglected in most European countries, though not in the USA. Too many people tend to regard the lime as a smaller lemon, not worth bothering with even when available in the shops. This hardly does justice to a highly important member of the citrus family that in its own individual way is highly nutritious, aggressively flavoursome, and uniquely pungent when used.

Details

Nutrition & Food Science, vol. 83 no. 2
Type: Research Article
ISSN: 0034-6659

Article
Publication date: 1 January 1942

Although a sheet of viscose film, such as cellophane, is so compact in structure as to be quite airtight, experimental work has shown that water vapour can evaporate as…

Abstract

Although a sheet of viscose film, such as cellophane, is so compact in structure as to be quite airtight, experimental work has shown that water vapour can evaporate as quickly from a vessel closed with it as from the open container. A wrapper composed of viscose film can be rendered impermeable to moisture vapour by covering the surfaces with a very thin layer of moisture‐proof transparent coating which often contains, as an essential ingredient, a small quantity of wax. It is wrappings of the latter “ moisture‐proof ” type which are normally used round cigarette cartons and often round biscuits and sweet packages. Unbroken films of wax are resistant to the passage of moisture vapour, and waxed papers are therefore largely used for the protection of foodstuffs. Not all waxed papers, or so‐called moisture‐vapour‐proof transparent wrappings, are satisfactorily impermeable to moisture vapour, and it is essential to test such materials to determine their actual protective powers. While complete protection against moisture exchange is advisable for most types of goods liable to dry out or for those which will deliquesce, it should be realised that there may be other factors that will prevent their being used. Some goods coated with cane sugar are found to keep best if in packings where they can “ breathe.” If, owing to a rise in temperature, the atmosphere in the moisture‐vapour‐proof wrapping should become saturated with moisture vapour, this would be deposited in droplets on the surface of the goods if the package were suddenly cooled. A dilute solution of sugar might be formed at the point of deposition, which would then be a favourable medium for the growth of aerial moulds and micro‐organisms. In many cases wrongly wrapped foods betray their deterioration by easily apparent signs, such as the hardness of bread, the stickiness of sweets or the odour of putrificd material. It is, however, quite possible for a loss in quality to occur which is only noticeable in flavour deterioration when the article is consumed, and an important instance of this is tea. Care must be taken that the wrapping itself does not impart a foreign flavour to the foodstuff packed in it, or induce one through permitting or accelerating chemical changes, such as oxidation (development of rancidity). Some of the transparent moisture‐vapour‐proof wrappings on the market have a strong flavour liable to contaminate goods wrapped in them, as have some waxed papers and ordinary “ boards ” used for cartons. Printing inks and adhesives used on cartons may also affect the flavour and odour of foodstuffs, unless properly chosen and properly used on the cartons. These odours will penetrate wrappers if the latter are not airtight, and instances are known where really expensive articles of food have been spoiled in flavour because strong‐smelling strawboards have been used as the foundation of the very elaborate and decorative boxes in which the foodstuff was packed. Rancidity development in fatty foods may be accelerated in several ways. It is well known that sunlight promotes the formation of rancidity, and fatty foods in ordinary transparent wrappings may deteriorate on this account. Attempts have been made to produce coloured transparent wrappers which will absorb the active light rays, and so prevent rancidity developing while at the same time allowing the goods wrapped to be visible. Some of these wrappers were so dark in colour that they were valueless for display purposes, but, according to advertised claims, some golden yellow transparent wrappers of good transparency and protective power are now available. There are available, however, wrappers treated with anti‐oxidants of the oat‐flour type which are claimed to arrest the development of surface rancidity of fatty foods packed in them. The last generation has seen the advent of scientific control and development in the catering business. Individual restaurants or hotels cannot afford to employ chemists, and with the exception of the large organisations owning a series of restaurants, the hotelier or restaurateur has to rely on the efforts of consultants or on the makers of the plant and machinery installed in his establishment. This help has been very valuable particularly as the amount of mechanical aids in restaurant kitchens has become during the last half century very considerable. Such devices as mechanical beaters or whippers, small doughing machines, mechanically or electrically controlled refrigerators, are but examples. Possibly one of the most interesting developments has been in the installation of mechanical washing machines for plates, dishes, cups, knives, etc. The number of pieces of china and cutlery is perhaps not appreciated. The modest two‐course lunch means that twelve articles, all of different sizes, shapes or materials of construction, must be washed; the seven‐course dinner requires 30–40 articles. The organisation to provide these articles in a steady stream sufficient for the needs of some hundreds of customers in the course of an hour or so must be very complicated, and one of the important cogs in the machine is “ washing up.” In the domestic scullery, unless particular precautions are taken, hot, hard water and soap are taken, and, by their admixture, produce a shiny scum which is mixed up with the soapy water. This scum and the water itself become loaded with grease during the washing process and the china is removed, carrying on its surface dirty, greasy, soapy water with its complement of soap scum. These are then wiped off with a drying cloth clean at first, but becoming gradually impregnated with grease, soap and scum, with the result that the surface of the china is finally covered with a thin transparent film of these objectionable substances. If the china, after removal from the wash‐bowl and when still wetted with grease‐laden soapy water, were rinsed under the hot tap until all this wash water were removed and replaced by clean hot water, and the china were then allowed to dry of its own accord, it would be chemically free from grease and would require no polishing. It would, moreover, not have to be handled at all. The essential factors of mechanical washing are therefore : (1) A detergent treatment that will emulsify all greasy substances and dislodge adherent food debris. Soap and suitable alkalis are used in this treatment. (2) A rinse treatment using clean hot water that will remove all detergent water from the china. (3) A drying treatment that is spontaneous and is carried out without touching the articles. Thus the production of washed articles entails a machine washer supplied with hot, softened water and suitable detergents; controls of rate of water supply, temperature, injection of detergent and rate of movement of china through the machine are of course all automatic. Treatment is generally in four stages—first a detergent treatment by high pressure jets, then a first and a second rinse treatment again by pressure jets, and finally a last rinse treatment provided by the incoming clean, hot, softened water taken directly from supply. The clean china is now so hot that within a few seconds of its emergence from the machine it is dry. It is then ready for use. It is only within the last century that “ gastronomy ” has been popularised, for the bulk of the population is now catered for with more care than ever before. The presentation of meals has advanced enormously, and the palatability of food has been studied with far more concern than ever before. Palatability, the controlling factor in eating, is a complicated attribute, and includes all those factors which can be considered as appealing to the senses. Sensation‐producing qualiites are odour, flavour, texture, temperature and appearance, appearance including form, design, size and colour. Palatability is no sure guide to food selection—“ Eat what you like and you need have no further concern about your food ”—modern scientific thought has demonstrated the fallacy of such a statement; nevertheless there are more factors of importance than the “ completeness ” of a food. To be informed that a mass of food contained all the necessary factors for proper nutrition has no effect on the gastric secretions, but the odour of a frying steak may make the mouth water : a badly baked meat pic, no matter how nutritious, lacks the appeal of one with the colour properly developed. This catering for masses of people has raised a number of important questions which the chemist has answered in many cases. As in the case of chain‐stores, where the public expects to get the same goods at the same price, be they purchasing in Manchester or Sidmouth, so in the case of chain‐restaurants the public demand the same standard of goods wherever they may happen to be eating. The consequence of this is that the cooking of a potato, the roasting of a joint, the frying of a fillet of fish, the production of a poached egg on toast, have to be standardised, and the chemist has collaborated with the engineer to produce the plant and machinery which will ensure, within reasonable limits, that the public be satisfied in so far as this consideration is concerned. Only a scientist can answer such questions as : for how many hours and under what conditions may a tin of sardines be kept after opening? What is the “ life ” of a meat pic in summer and what in winter? How long can Russian salad prepared under standard conditions be kept? What are the best conditions for the preparation and keeping hot of boiled cabbage : Incidentally the scientist has been forced to give attention to many problems outside the realm proper of food : for example, the standardisation of the crockery and glasses to reduce breakage to a minimum, the question of the colours to be used for the plates and cups and saucers, so that fading by the chemical treatment or by mechanical abrasion in washing or in general use be brought to a minimum. The solution of problems of the service of food in restaurants is not perhaps a spectacular field of work for the scientist, but, in view of the millions of meals served daily in England, its importance can hardly be over‐estimated. Such are some of the impacts of Science on Food. The sketch is naturally incomplete and many aspects have not been mentioned at all. The application of new scientific knowledge to food problems is continually assuming greater importance in the feeding of the people. This does not imply that science is supplanting the art of the chef; it may modify, perhaps simplify, the processes concerned with the preparation of food, but its main function is to interpret the principles on which the art is founded, and to adapt the accumulated knowledge to modern conditions.

Details

British Food Journal, vol. 44 no. 1
Type: Research Article
ISSN: 0007-070X

Article
Publication date: 1 September 1912

It is seven years ago since I first took up the estimation of dirt in milk samples; there had been numerous complaints about dirty milk sold in Chester, and the Public…

Abstract

It is seven years ago since I first took up the estimation of dirt in milk samples; there had been numerous complaints about dirty milk sold in Chester, and the Public Health Committee asked me if it would not be possible to estimate the dirt, so that proceedings could be taken against the milk sellers.

Details

British Food Journal, vol. 14 no. 9
Type: Research Article
ISSN: 0007-070X

Article
Publication date: 1 November 1941

Heat treatment, in view of later knowledge, is seen to have other effects than to destroy or lower the vitality of micro‐organisms initially present; there are the more…

Abstract

Heat treatment, in view of later knowledge, is seen to have other effects than to destroy or lower the vitality of micro‐organisms initially present; there are the more obvious changes of flavour and of consistency brought about by the partial cooking, but there are also the possible lowering of the vitamin potency and the still more subtle changes in the salts which may, after heat treatment, be rendered less available than in the raw product. The importance of these considerations cannot be too much stressed when it is remembered that heat treatment is, generally speaking, an inherent stage in the process of canning. It is the heat treatment which preserves the goods, the sealing of the can being merely a means of prevent re‐contamination. The chemist, no less than the physiologist, has been much concerned with the changes in foods caused by heat treatment as a method of preservation, and, as a result of his investigation, there is now a better understanding of the changes which take place, with a consequent improvement in the methods of processing. For a number of years, however, this country, in common with many others, has relied, in so far as its supplies of meat are concerned, on products preserved by “cold,” and the freezing of beef, the chilling of mutton, have made available to us the cattle of the Argentine and the sheep of New Zealand. Initially the processes employed were crude, the post‐mortem changes were imperfectly understood, conditions of storage, before, during and after shipment, were haphazard, and the methods of defrosting far from scientific. How far the methods have advanced, and to what extent the scientist has been concerned in the elucidation of the many problems, will be realised from the reports of the Food Investigation Board. It is not suggested that all the advance is due to the work of the Low Temperature Station a Cambridge—much has been done in other countries‐but the investigations carried out by the scientists a this station have been fundamental. Food producers in America were the first to realise the importance of the latest development in freezing, the advent of the “ Quick Freezing Processes ” marking a distinct advance in technique. When cellular tissue is normally frozen and subsequently defrosted, rupture of the cells may have occurred and the structure of the substance consequently partially broken down. When, however, the tissue is quickly brought down to a very low temperature, it is found that in many cases this breakdown in tissue does not take place. These principles have been applied to commercial installations, and fish, meat, fruit and vegetables so treated show on defrosting remarkably little change in character. Preservation by desiccation is a method employed for certain materials with great success. Sun‐drying of fruits (sultanas and dates, to quote but two) and the sun‐drying of cereal products such as macaroni is still practised. An important industry concerned with the drying of milk has developed in most milk‐producing countries, whilst dried eggs and dried egg‐albumin form important items of commerce. It is obvious that the object of concentrating such substances as fruit juices, milk and vegetables and animal liquid extracts is ideally to reduce the water content and obtain a product which, when the water is ultimately restored, gives a solution or material having the original taste, aroma and food value. The effect of heat is often, however, to change these characteristics, and although by the use of a vacuum the temperature to which the substance is submitted is lowered, changes still take place, and much of the aroma depending on volatile constituents is lost. To a very great extent this has been overcome by a method of desiccation which is essentially partial freezing, a method which has not yet received much publicity as it has only lately emerged from the experimental stage. The practical application of this principle is due to Dr. G. A. Krause, of Munich, who has invented and designed a dual process of concentration. In this process the liquid is first concentrated by freezing out water as ice, which is removed by mechanical separation in a centrifuge. By ingenious mechanical and regenerative devices this process has been made extremely efficient, the losses being only 1–2 per cent. of the original juice, although the efficiency is not maintained when the solids‐content of the product has been raised to 40–50 per cent. This liquid is then further concentrated by evaporation at a low temperature, about 10°–15° C. The differential evaporation of water as compared with the aromatic flavour constituents occurs because the removal of water as vapour at this temperature depends solely on the rate of diffusion of the molecules into the gas space. As water has a small molecule compared with the large molecules of the esters, ethers and alcohols of the flavouring substances, it escapes more readily ; the conditions of evaporation as given in the patent are all designed to aid this escape. A reduction in pressure may be used to speed up the process without interfering with the differential diffusion, and the provision of an atmosphere of small molecules (e.g., hydrogen) also has the same effect. A large surface for the evaporation is made by spreading the liquid as a thin continuously renewed film. The condenser is situated very near the evaporating liquid to remove the water molecules quickly (a distance of 3 cm. is the maximum diffusion path). The atmosphere may be circulated or disturbed to hasten the diffusion and, most ingenious of all, it may be blown towards the evaporating liquid when, if a velocity is used just greater than that of the heavy molecules leaving a liquid surface, the loss of flavour may be entirely eliminated while the rate of water evaporation is only reduced by 10 per cent. By these means a concentrate containing as much as 65 per cent. solids and capable of storage without deterioration at ordinary temperatures may be prepared, and 80 per cent. of the original vitamins retained. The use of refrigeration in the preservation of food has necessitated the use of refrigerated transport to complete the links between producer, manufacturer, retailer and customer. The variety of commodities and the different conditions they need create varying demands on the methods of insulating and refrigerating transport vehicles. The British railways have 4,000 refrigerated railway vans, and such vans, containing perishable produce, came regularly to England from Austria and Italy by way of the train ferries. These vans are designed for fairly high temperatures, 35–40° F., and long hauls, and use ice as a refrigerant. At the other end of the scale is the road vehicle, which may have a temperature as low as 0° F., but is only on its journey about 12 hours. It is in these road vehicles that the greatest advances have been made, for conditions in England do not justify the railways in expenditure on elaborate equipment. The early road vehicles were insulated boxes on a lorry chassis and were refrigerated by ice and salt, which was “messy” and caused bad corrosion of the chassis. The introduction of an eutectic solution, virtually a mixture of a freezing salt and water in a definite proportion, which was frozen as a whole in a sealed tank, was made some few years ago. This removed the “messiness,” conserved the salt and produced greater efficiency and a more stable temperature.

Details

British Food Journal, vol. 43 no. 11
Type: Research Article
ISSN: 0007-070X

Article
Publication date: 1 March 1942

Twenty‐three years ago the most frequently met among many slogans was “ Food Will Win the War.” To‐day our food problems are fully as important to our defence; but they…

Abstract

Twenty‐three years ago the most frequently met among many slogans was “ Food Will Win the War.” To‐day our food problems are fully as important to our defence; but they present many new aspects. Then our prime duty was to save food : now it is to consume food in the way most conducive to fitness. Our knowledge of nutrition has advanced so rapidly that much of it is too new to have been assimilated into our everyday thought and practice. Yet it is precisely as guidance to everyday use of our familiar foods that the newest knowledge of nutrition can be of most benefit: of benefit both to the one‐third of our people who are officially declared “ ill‐nourished,” and to the great majority of the rest of us as well. For while finding that much of our previously baffling disease and frustration is due to shortage of certain nutritional factors in the food supply, research has also shown that a more scientifically guided use of our everyday foods constitutes a sort of superior chemical engineering of our own mechanisms which can increase the vitality and efficiency even of those people who are already healthy and efficient. The relations of nutrition to the functioning of the mind are, of course, more difficult of controlled investigation and not yet as objectively demonstrable as to the effects of food upon bodily functions and length of life. But careful research is now showing that even within the range of fully normal conditions, our daily food choices have much more important effects than science ever previously supposed upon that internal chemistry that directly environs and conditions all our life processes. The blood is the great mediator of this internal environment, and the same blood circulates through the brain as through all the other organs of the body, bringing its help or its hindrance to both mental and muscular activities. True there is much which remains to be clarified by further research; but the already established findings, of recent and current nutritional investigation, need only to be more widely known and used in order to make our people much stronger for the defence of our civilisation, and for its permanent advancement when the emergency has passed. In our “ intellectual climate ” of the moment there is still a good deal of inertia because the newest knowledge is not yet sufficiently understood, while at the same time the new view is perhaps being over‐coloured by some writers. This paper therefore does not seek to add more assertions; but rather to review objectively the evidence on what the Council of National Defence has announced as one of our present‐day needs, “ to make the American people nutrition‐conscious in terms of the nutritional science of to‐day.” Nutrition presents three major aspects : (1) that in which food serves as fuel to supply energy for the activities of the bodily machine; (2) that of the assimilation of certain food constituents into structural material first for the growth and later for the upkeep of the body tissues; and (3) the utilisation of food substances either directly or indirectly to serve the body in those self‐regulatory processes by which it maintains its relatively “ steady states ” or essential internal environment. It is in its energy aspect that nutrition has most fully arrived at the status of an exact science. Expert opinion is well agreed on the fundamental principles of the energy transformations in the body, on the values of the foodstuffs as sources of energy, and on at least the broad lines of theory as to the influence of different bodily conditions in determining the energy need. On the latter points, especially, many laboratories are actively engaged in increasing the precision of present knowledge, and at least three well‐endowed nutrition laboratories—those of the Carnegie Institution, of the Russell Sage Institute, and of the Rochester University Department of Vital Economics—are devoting their resources especially to the perfection of the energy aspects of nutritional knowledge. The protein aspect of nutritional research has also reached a relatively mature status with well‐defined objectives. Among many other laboratories working in this field, that of the United States Department of Agriculture is giving special attention to the purification and description of the proteins themselves; and the laboratory of physiological chemistry of the University of Illinois is very actively investigating the nutritional relationships of the individual amino acids, with the generous support of the Rockefeller Foundation. We may look forward with confidence and great gratification to a presumably fairly near future in which this aspect of nutritional need can be stated quantitatively in terms of ten individually indispensable amino acids. The catalysts which make the chemical processes in the body go fast enough to support life overlap and in a measure integrate the subject matter divisions of the chemistry of nutrition. They function in the energy aspect; and in their own chemical constitutions they are derivatives of proteins (or their amino acids), mineral elements, and vitamins. This very active field of research is quite as frequently classified with general biochemistry as with nutrition. Until its current era of “ newer knowledge,” the chemistry of food and nutrition had for several decades faced the dilemma that foods could be analysed as elaborately, and their composition accounted for with as close an approach to one hundred per cent., as other natural materials; and yet nutrition could not be sustained with pure mixtures of the substances that the analyses revealed. Seeking deeper insights, chemists broadened their research methods to include the systematic use of feeding experiments with laboratory animals, carried on with as careful attention to accuracy of controls as in other experimental researches in the exact sciences. This extension of method in chemical research has been rewarded with a rapid series of discoveries of substances which are essential to our nutrition, but whose very existence was, until recent years, either entirely unknown or only vaguely apprehended. Neither in chemical nature nor in nutritional function do these substances have much in common with each other. That they came to be called by the group name vitamins was not the result of their being naturally related, but rather of the two circumstances, (1) that they were all discovered through the use of the same development of research method, and (2) that the discoveries of their existence and importance followed each other too rapidly for physical isolation and chemical identification and nomenclature to keep pace. The latter, however, are steadily catching up, and in several cases new names, which are individually distinctive of either the chemical structures or the historic associations of the substances, have been coined and are coming into general use.

Details

British Food Journal, vol. 44 no. 3
Type: Research Article
ISSN: 0007-070X

Article
Publication date: 1 September 1941

Cooking depends on two factors, time and temperature, and the second factor, temperature, has to be varied according to the type of product. The problem of the chemist…

Abstract

Cooking depends on two factors, time and temperature, and the second factor, temperature, has to be varied according to the type of product. The problem of the chemist then is to define the time at the given temperature necessary for a pie of a given size to be cooked correctly to yield a product satisfactory both to the palate and eye and from the point of view of its bacteriological standard. Where the oven used is of the travelling type—a type where the goods are fed into one end of the oven, the base of which is a moving band, and carried to the other end where they are discharged—an instrument has been designed which records not only the temperature but also the rate of travel, thus indicating the two factors, temperature and time. For the successful control of manufacture there are two aspects of primary importance. A stock‐control demonstrates that as a result of the consumption of certain amounts of raw materials a definite quantity of finished goods has been prepared for sale. This control however does not ensure that all the goods so produced are of the same composition, for under‐consumption in some may be offset by over‐consumption in others. The laboratory activities ensure that this possible inequality of final product does not take place. Therefore a joint control by means of stock control and laboratory control ensures that not only is the correct yield of finished product obtained from the amount of raw materials used, but also that the goods produced are of uniform character and composition. Where such a system is in force not only is the operator controlled but also the factory management; for a process having been standardised by this joint control, no deviation is allowed from the issued manufacturing instructions. But it must be stressed that the correct interpretation of this method does not stultify the initiative of the management staff; they still can make experiments, can still suggest alterations, but not until their suggestions have been incorporated in the official control can any changes be made in the method of manufacture. By constant attendance of chemists in the factory, by constant sampling of food in process of manufacture, by continued analysis and examination of the final product and by the stock control, the adherence to agreed recipes is assured. As mentioned previously the chemist is the interpreter of the art of the technician, but he is more than that. The dietitian can indicate what in calories, in vitamins and in trace elements is necessary to healthful feeding, but it remains for the food chemist with the knowledge of the technical expert to translate these requirements into practical terms so that the food manufacturer can produce an article of diet such that the consumer eats it with pleasure, thereby obtaining the maximum benefit. Moreover, ideas come for new food products, for new methods of production from people daily in touch with the actual manufacture; many ideas are brought by people from outside and ideas are given by competitive articles. The chemist puts the idea finally into production form. A recipe from Mrs. Beeton's Cookery Book cannot be applied as it stands to mass production, but the food chemist can often indicate those changes which will be necessary to translate such a recipe from the kitchen scale to the factory scale, from the scale of the gallon saucepan to the boiling tank with its charge of a ton weight. Investigational work is of a threefold character, for it is concerned with the modification and improvement of methods of analysis and control, with the study of fundamental chemical problems concerned with food materials, and with the development of manufacturing methods. Analysis for food control purposes must be very specialised in character. Whereas time is of little importance to the Public Analyst examining, for example, a sample of chocolate cake to see that it contains the implied amount of cacao matter, the control chemist analysing a sample of fruit‐pie‐filling, with a whole batch of such filling awaiting his report, is concerned essentially with the speed of the operation. Every control laboratory has to develop methods of analysis suitable to the end in view, and every new process, every modification of a standard process, a change in composition of raw materials, may necessitate an investigation into the technique of the method to be used. Investigations of a fundamental character are not necessarily stimulated with the idea of ultimate practical use to the firm, except in so far as they develop the initiative, the experimental sense, the interest of the chemical staff. It has however been a noticeable fact that often ideas have arisen from fundamental work which have been ultimately of great use in the preparation of food products. Sometimes many years have elapsed between the prosecution of a piece of research work and the sudden remembrance of a small fact, a peculiar reaction, which has been made use of to simplify control or to change the method of a section of the process of manufacture. The transition from the kitchen methods of preparation to the manufacture of food on a large scale has demanded much investigational work. Mass production and mechanisation are not synonymous, but they are so closely related in the modern world that the one needs the other for success. Mass production demands mechanisation and mechanisation, to be economically sound, requires mass production. Mechanisation is not possible unless the process to be mechanised is understood; and it is here, in the food industry—as in other industries—that the chemist has helped industry to develop. The operator engaged in hand‐dipping chocolate centres is able, with her palette‐knife and mass of chocolate in a warm bowl, to work the chocolate couverture continually, the appreciate the changing conditions of the small mass, to correct by her skill any change of consistence and to produce thereby a product of very nearly constant appearance and composition. But when the unit of chocolate mass is increased from a few pounds to hundredweights, and when the centres in their thousands pass through a cascade of chocolate mass and are so enrobed, no such continuous adjustments can be effected. Consequently the chemistry and the physics of chocolate couverture have to be understood; the effect of time and temperature on the fluid couverture, the effect of forced cooling on the enrobed chocolates have to be studied. The chemist has to carry out experiments and to indicate as a result of his investigations the conditions which will ensure a really standard product. Examples could be quoted in connection with baking problems, with jam boiling problems, and in fact with problems from every branch of food production. Mechanisation entails the use of machinery and the metals of which the machinery is constructed may have an unexpected result on the product being manufactured. The question of this type of contamination is of two‐fold interest. In the first place, the amount of metal taken into solution, either by purely chemical reaction, or by mechanical abrasion, must not be such that it will have any adverse effect on the health of those subsequently eating the food; in the second case, the effect of minute proportions of foreign metals on the flavour or keeping qualities must be studied; for example, tea is never brewed in an iron pot because a chemical reaction takes place by which a highly coloured compound is produced and gives to the infusion a blackish colour. This is an instance of a chemical change which takes place immediately. An example of a different type is provided by the milk industry. The flavour of milk is delicate and easily affected, and one change which may take place in it is the development of a “ tallowy ” flavour. The chemistry of the reactions which result in the development of this particular “ off ” flavour is not well understood, but one factor has been investigated, namely the effect of certain metallic contaminants. Coolers for milk—and obviously all milk has to be cooled subsequently to being heated to pasteurisation temperature—are often made of tinned copper. In time the constant cleaning which is necessary wears off the tin in certain places, small areas of copper appear, almost too small to be noticeable—and the milk then comes in direct contact with this metal. Copper, present only to the extent of a few parts in every million parts of milk, has a stimulating effect on the changes which result in the development of the “ tallowy ” flavour. Yet another example. The metal of which cans are made for the canning industry is iron covered with a thin layer of tin. But canned goods are often kept for long periods of time. Sometimes the cans begin to swell, the ends become somewhat rounded in shape. That may be caused by a very simple chemical reaction, not concerned with any spoiling changes taking place, but due to the reaction between the acid contents and the iron; the active constituents of the contents have gradually found their way through microscopic pinholes in the tin layer and the gas hydrogen is the result, the generation of which becomes eventually noticeable by the swelling of the can. These three examples, the first immediately apparent, the second booming noticeable in a few hours, and the last which may not be observed for months, indicate different types of effect of metal on food stuffs. This last could naturally be very much expanded, but the obvious conclusion is that plant must be considered in relation to the purpose to which it is to be put. Mass production demands consideration too from the hygienic standpoint, for difficulties on this score are inherent in food production. Not only have the methods of production to be studied from this point of view, but consideration has to be given to the bacteriological condition of the basic materials. This is generally impossible in small scale production and it is obviously also impossible, no matter what the scale of production, for each and every tin of canned goods to be examined, or every milk pudding to be submitted to bacteriological tests, but experience of continued tests gives the clue to those factors which must be watched and the precautions to be taken. Government action has been taken in many cases. For instance, in the delivery of meat the implementing of the precautions required by law has resulted in meat reaching the butchers or the food manufacturer in far better condition than previously and has reduced wastage caused by bacteriological spoiling. Consideration of the condition of raw materials brings to mind frozen eggs. Science has proved that eggs properly frozen are far more hygienic than eggs in shell so far as the food manufacturer is concerned. Moreover it can be definitely stated as a result of a large number of tests that Chinese frozen eggs from reputable firms in China are of the highest standard possible. The freezing of eggs on the large scale in China has reached a magnitude and a standard not surpassed anywhere in the world. This has been achieved by application of methods based entirely on scientific principles. Mass production has entailed investigation of methods whereby the onset of spoiling can be retarded. A loaf of bread immediately it is cooled after leaving the oven, be it the kitchen oven or the travelling oven baking 1,500 loaves an hour, has certain characteristics of freshness. How can those characteristics be retained? Night baking enables the householder to receive first thing in the morning a loaf baked an hour or so previously, but mass‐produced bread entails distribution over a wide area and the hour or two may spread out to six or seven before the housewife receives her loaf.

Details

British Food Journal, vol. 43 no. 9
Type: Research Article
ISSN: 0007-070X

Article
Publication date: 1 November 1924

1. Preservatives should be prohibited in all articles of food and drink offered or exposed for sale whether manufactured in this country or imported, except that—(a

Abstract

1. Preservatives should be prohibited in all articles of food and drink offered or exposed for sale whether manufactured in this country or imported, except that—(a) Sulphur dioxide only should be permitted, (1) in sausages in amounts not exceeding three grains per pound, (2) in jam in amounts not exceeding 0·3 grains per pound, (3) in dried fruit in amounts not exceeding seven grains per pound, (4) in preserved (but not dried) whole fruit or fruit pulp in amounts not exceeding five grains per pound, (5) in beer and cider whether in bottle or in cask in amounts not exceeding five grains per gallon, (6) in alcoholic wines, non‐alcoholic wines, and cordials and fruit juices sweetened and unsweetened in amounts not exceeding three grains per pint; (b) Benzoic acid only should be permitted (1) in coffee extract in amounts not exceeding three grains per pound, (2) in non‐alcoholic wines and cordials and sweetened and unsweetened fruit juices (as an alternative to sulphur dioxide) in amounts not exceeding five grains per pint, (3) in sweetened mineral waters and in brewed ginger beer in amounts not exceeding one grain per pint. The methods of estimating the foregoing preservatives should be prescribed by the Minister of Health.

Details

British Food Journal, vol. 26 no. 11
Type: Research Article
ISSN: 0007-070X

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