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This paper aims to show that a simplified surface fitting model can be efficient in determining the energy consumption during milk cooling by an on-farm direct expansion…
This paper aims to show that a simplified surface fitting model can be efficient in determining the energy consumption during milk cooling by an on-farm direct expansion bulk milk cooler (DXBMC). The study reveals that milk volume and the temperature gradient between the room and the final milk temperature can effectively be used for predicting the energy consumption within 95% confidence bounds.
A data acquisition system comprised a Landis and Gyr E650 power meter, TMC6-HE temperature sensors, and HOBO UX120-006M 4-channel analog data logger was designed and built for monitoring of the DXBMC. The room temperature where the DXBMC is housed was measured using a TMC6-HE temperature sensor, connected to a Hobo UX120-006M four-channel analog data logger which was configured to log at one-minute intervals. The electrical energy consumed by the DXBMC was measured using a Landis and Gyr E650 meter while the volume of milk was extracted from on the farm records.
The results showed that the developed model can predict the electrical energy consumption of the DXBMC within an acceptable accuracy since 80% of the variation in the electrical energy consumption by the DXBMC was explained by the mathematical model. Also, milk volume and the temperature gradient between the room and final milk temperature in the BMC are primary and secondary contributors, respectively, to electrical energy consumption by the DXBMC. Based on the system that has been monitored the findings reveal that the DXBMC was operating within the expected efficiency level as evidenced by the optimized electrical energy consumption (EEC) closely mirroring the modelled EEC with a determination coefficient of 0.95.
Only one system was monitored due to unavailability of funding to deploy several data acquisition systems across the country. The milk blending temperatures, effects of the insulation of the DXBMC, were not taken into account in this study.
The developed model is simple to use, cost effective and can be applied in real-time on the dairy farm which will enable the farmer to quickly identify an increase in the cooling energy per unit of milk cooled.
The developed easy to use model can be used by dairy farmers on similar on-farm DXBMC; hence, they can devise ways to manage their energy consumption on the farm during the cooling of milk and foster some energy efficiency initiatives.
The implementation of the developed model can be useful to dairy farmers in South Africa. Through energy optimization, the maintenance of the DXBMC can be determined and scheduled accordingly.
The value which can be placed upon the rights of property in a name of a commodity, a food or drink, perhaps famous all over the world, which has come down to us through the centuries, is incalculable. Most of such foods and drinks have a regional association, and are prepared according to methods, often secret, handed down from one generation to another and from locally grown and produced materials. Nowhere are such traditions so well established as in cheese‐making and the wine industry. The names do not signify merely a method of manufacture, since this can be simulated almost anywhere, nor even the raw materials, but differences in climate, the soil and its treatment, its produce, harvesting, even in the contaminants of environment. Rochfort cheese, for example, is made from ewe's milk, but most important, with mould growths found only in the caves of that part of France where it is stored.
Natural selection—survival of the fittest—is as old as life itself. Applied genetics which is purposeful in contrast to natural selection also has a long history, particularly in agriculture; it has received impetus from the more exacting demands of the food industry for animal breeds with higher lean : fat and meat : bone ratios, for crops resistant to the teeming world of parasites. Capturing the exquisite scent, the colours and form beautiful of a rose is in effect applied genetics and it has even been applied to man. For example, Frederick the Great, Emperor of Prussia, to maintain a supply of very tall men for his guards—his Prussian Guards averaged seven feet in height—ordered them to marry very tall women to produce offspring carrying the genes of great height. In recent times, however, research and experiment in genetic control, more in the nature of active interference with genetic composition, has developed sufficiently to begin yielding results. It is self‐evident that in the field of micro‐organisms, active interference or manipulations will produce greater knowledge and understanding of the gene actions than in any other field or by any other techniques. The phenomenon of “transferred drug resistance”, the multi‐factorial resistance, of a chemical nature, transferred from one species of micro‐organisms to another, from animal to human pathogens, its role in mainly intestinal pathology and the serious hazards which have arisen from it; all this has led to an intensive study of plasmids and their mode of transmission. The work of the Agricultural Research Council's biologists (reported elsewhere in this issue) in relation to nitrogen‐fixing genes and transfer from one organism able to fix nitrogen to another not previously having this ability, illustrates the extreme importance of this new field. Disease susceptibility, the inhibition of invasiveness which can be acquired by relatively “silent” micro‐organisms, a better understanding of virulence and the possible “disarming” of organisms, particularly those of particular virulence to vulnerable groups. Perhaps this is looking for too much too soon, but Escherichia coli would seem to offer more scope for genetic experiments than most; it has serotypes of much variability and viability; and its life and labours in the human intestine have assumed considerable importance in recent years. The virulence of a few of its serotypes constitute an important field in food epidemiology. Their capacity to transfer plasmids—anent transfer of drug resistance— to strains of other organisms resident in the intestines, emphasizes the need for close study, with safeguards.
At the annual meeting of Cow & Gate Ltd., in April, the Chairman of the Company said: “I think everyone looks forward to the day when the Ministry of Food ceases to exist. This is not meant in any way to reflect upon the ability with which this Ministry was administered during the war and immediate post‐war years, but a Ministry of Food should not really be necessary in peace‐time. Before the war the milk industry was largely governed by the Milk Marketing Board, and we have great admiration for the Board’s activities; but it was representative only of the producers’ side of this great industry. The distributive and manufacturing trade in the British Isles has grown out of all knowledge since 1939, and this country has relied more and more upon home manufacture as well as home production, both during and since the war. If some of the powers at present delegated to the Ministry of Food are to be placed in other hands, they should in all fairness be shared by the producers, distributors and manufacturers, who have at least an equal stake financially and who should be equally capable of discharging these duties in a conscientious and publicspirited manner. In my opinion, moreover, the day is long outlived when it can possibly be expedient or in the public interest to allow a statutory body representing purely producers’ interests to be the sole arbiter in regard to such a vital matter as the nation’s milk supply.”
The main ingredients are soya flour, separated milk powder and oatmeal. In some mixtures vitamin concentrates are included. In theory they are admirable, but the chief objection to soup as a meal for a child is that it is difficult to get 1,000 calories into the stomach, even with a good hunk of bread. Thick soup is too filling. It is excellent for emergency use, as experience with the Ministry of Food canned thick soups has shown under “blitz” conditions. But, on bread and thick soup, a child feels full before it has eaten the 1,000 calories it is desirable to get into him. Health of children is, from all reports, whether from public, private or elementary schools, remarkably good. We were not a little worried at this time last year about the adequacy of the supply of first‐class protein for growing boys and girls. The position is now reasonably satisfactory and every effort is being made to see that what is required for development of muscle and bone shall be provided. You, Sir, have on numerous occasions emphasised your determination to see that the younger generations shall not suffer as the younger generations suffered in the last war from diet deficiencies. The spirit that has moved you to take that firm stand will be a powerful force in the post‐war period. I can foresee, and hope to live to see, the day when every child in the country shall be able to get a good nourishing meal at school if the parents so wish. There is another important aspect of this vast expansion of the school feeding programme. The proper planning of school meals is only one way in which the child will benefit. Education in the simple facts of food values will be an essential part of the school. Impressions formed in the minds of these young people will last their lifetime. That is fully recognised in America, where a big concerted drive is about to begin to put nutrition propaganda before every section of the nation. It is true that food habits of a lifetime are sometimes hard to change. Whether they are based on long‐established custom or deep‐rooted fallacies, or both, they are not readily given up by adults. No better illustration could be given than the reluctance of the mass of the people to purchase wheatmeal bread when there was a choice between that and the ordinary white loaf. On the one hand we were urged to force wheatmeal bread down the throats of the people and were assured that they would like it when they came to understand that it was good for them. At the other extreme we were emphatically told that the public actively disliked a dark loaf. My own impression, from a close study of the matter, is that the majority of people are “conditioned,” to use a much overworked word, to white bread and give little thought to other variety. They are certainly apathetic to any appeals based on food values. Most people go into a shop, ask for a loaf of bread, get a white one, as has always been the case unless brown were specifically asked for, and give no more thought to the matter. A striking example of this indifference has been provided recently in America, where there has been extensive commercial development of the manufacture of white flour “fortified” by additions of synthetic vitamins. Large‐scale production has been in progress for about a year. At first the public, stimulated by a vigorous publicity, bought the new type of bread. Sales rapidly mounted. That it was largely novelty rather than vitamins that sold the bread in the first instance appears to be shown by the steady fall in sales that has recently occurred. Had the public as a whole actively disliked bread that is not white, as we were so often assured, it would have been reasonable to expect a volume of protest when National Bread came into general use. No such reaction occurred. On the other hand, favourable comment has been widespread. The war‐time nutrition policy that aimed at improving the food value of bread either by use of long‐extraction flours or artificial reinforcement will certainly be reflected in post‐war developments. What line they will take is not yet clear. It is certain, I believe, that minimum requirements, at least in respect to vitamin B1, will be laid down. Whether particular methods of manufacture will be specified is another question. In this connection it is appropriate to mention that a new method of milling wheat has been devised as a result of collaboration in Canada between the Government Cereals Research Department, certain milling interests and an enthusiastic pioneer who is leading Canada's nutrition “drive,” Dr. F. Tisdall, of Toronto. This method yields a flour, as rich in vitamin B1 as an 85 per cent. wheatmeal and containing considerably more of other important nutrients of the wheat berry than the ordinary type of wheat flour. If there is a public taste in regard to the whiteness of its flour, and if it is of real significance, we have here what appears to be the perfect compromise because the new Canadian flour—to be known officially as “Canada Approved”—is truly white. In passing, I may add that to encourage the production of this type of flour in Canada the addition of synthetic vitamin B1 to white flour has been made illegal. But although we must admit a large measure of resistance in adults to new ideas about food I by no means share the view that it is always a matter of the greatest difficulty to change their food habits. Twenty years ago, perhaps even ten, a workman who openly drank a glass of milk in front of his mates would have had to face a barrage of appropriately phrased ridicule. America led the way with its encouragement of milk in factories. When the war broke out we were rapidly following her lead. Milk was being drunk in considerable and increasing volume in factories. People no longer stopped to stare if they saw a big, husky navvy drinking from a bottle of milk. We were told, when we tried to get vegetable salads into workers' canteens, to make good the loss of vitamin C which is almost unpreventable in large‐scale cooking, that the “hands” would not touch them. They didn't, when little or no effort was made to explain in simple terms what they were for or to serve them attractively. The conventional idea that salads can consist only of lettuce, cucumber and tomato and that they are only to be eaten with cold meat was hard to uproot. But, wherever canteen supervisors have taken even moderate pains to encourage people to try salads—and I am speaking of war‐time salads of shredded cabbage, grated carrot, potatoes, etc.—there has been a record of success. Of course, everything depends on who runs the canteen. In one factory in London it was found not only possible, but a simple task, to make a midday meal of the “Oslo” type popular in summer months, even with men doing relatively heavy work. The serving of a helping of vegetable salad as part of the meal has proved a success in a number of communal restaurants. It is invariably eaten and most people like the innovation. If it were offered as a separate item relatively few would ask for it, merely because they are unaccustomed to do so. This small helping of fresh vegetables is of very great nutritional importance. Large‐scale cooking in restaurant kitchens involves serious losses of vitamin C. Some are caused by vegetables being prepared and left soaking many hours before they are cooked, sometimes overnight. Even more serious losses occur during cooking. Finally, cooked vegetables which have to be kept hot for several hours suffer a further serious reduction in the amount of ascorbic acid. The result is that instead of providing at least 25 mg. of vitamin C, as we would like it to do, an ordinary canteen meal may contain no more than 5·20 mg., particularly in winter months. It is all very well for the nutritional expert to tell us that by taking certain precautions and modifying the methods of cooking vegetables a large proportion of this loss can be prevented. The hard fact is that it is exceedingly difficult, sometimes quite impracticable, to change the organisation and routine of a large kitchen. We know of no means of preventing loss of C when cooked vegetables are kept hot in insulated containers, as is frequently necessary. In four hours the ascorbic acid content of a helping of cooked potatoes can fall from about 6 mg. to 2 mg., and that of one of “greens” from 25 mg. to 10 mg.; losses, that is, of the order of 60 per cent. The small helping of vegetable salad overcomes the difficulty. We have found that there is relatively a small loss when fresh vegetables are shredded or grated. A helping of about 3–4 ozs. of mixed chopped cabbage, carrot, turnip and beetroot gives from 20 to 40 mg. of vitamin C: an amount ample for the average person's daily need. We are trying very hard through the medium of propaganda by the Ministry of Food and Board of Education to make the people salad‐conscious; in the hope that salads will become an accepted part of the daily meals of an increasing number of families, schools, institutions and hospitals. If the movement really gains good ground during the war period, when the choice is so restricted, it should spread rapidly when normal times come and the green‐grocer's shops show once again the rich variety of produce from home and overseas. It has been a hard, uphill fight to make “the man in the street” believe that garden vegetables are a good substitute for fruit, in the nutritional sense. I think we have made good progress, but there are many still unconverted. It is important that the truth of this matter should be widely known. Of the fruits we ate in ordinary times only oranges, grapefruit, blackcurrants, redcurrants, gooseberries and strawberries are particularly good sources of C. Apples, pears, bananas, cherries and plums are relatively poor in this respect. When most of these fruits are unobtainable, as at present, it is important to know that we can easily obtain our vitamin C from cabbage and sprouts, cauliflower and broccoli. We recently published, in collaboration with Dr. H. V. Taylor, of the Ministry of Agriculture, tables showing that a well‐cultivated allotment of the regulation size of ten rods, a mere 300 sq. yards, will provide all the vitamin C required for a family of four during each month of the year, even after liberal allowances for wastage and cooking losses. Moreover, the same crops will provide no less than half the vitamin A required by a family of that size. No stronger evidence of the immense value of an allotment could be produced. It will be a thousand pities if every effort is not made to sustain the allotment movement to the greatest possible extent after the war. After the last war the area cultivated in this manner fell rapidly as parks, building sites and other grounds were taken back for their original purpose. Of necessity, much land will have to be given up when peace comes again, but if our post‐war world, is, as Sir Stafford Cripps remarked on Sunday last, to be “consciously planned for better living conditions,” the immense national importance of allotments must not be ignored as it was in the “reconstruction” after 1918. Nor do I feel we should regard the British Restaurant as a temporary war‐time expedient. There will doubtless be a certain amount of agitation after the war directed towards their abolition.
It must be difficult for many to contemplate the numerous changes in progress and projected without wondering why it all has to happen now. Of course, there have always been with us those who would change everything, even those who would spoil; all seemingly unable to leave anything alone; unwillingly to let us be for what we are. Then there are those who dislike change of any kind in their familiar environment and strangely, children are the most conservative of us all, and others who do not object to change when it is necessary, but only when it is change merely for the sake of change. The changeover to the metric system, or to use one of the grating terms of the new technological language, metrication, must be accepted as a natural sequence to decimal currency and advances in industry. A revolution in weights and measures, it will indeed present very great problems throughout the country and at all levels, which will dwarf those presented by the switch to decimal coinage, for at worst, these may be just confusing to the general public and a price‐raiser in small‐value commodities, despite assurances to the contrary.
Three events of significance to this country took place in 1899 – the British Food Journal was launched, Australia retained the Ashes, and the Boer War hostilities commenced. If challenged on the order of their importance, cricketers and Empire‐builders may be excused their preference. However, looking at it purely from the standpoint of pro bono publico, the dispassionate observer must surely opt for the birth of a certain publication as being ultimately the most beneficial of the three.
During the year the information service of the Food Investigation Organisation has been considerably extended. The Index to the Literature of Food Investigation, which was published quarterly, has been replaced by a two‐monthly journal, Food Science Abstracts, which also contains reviews and survey articles.
The long controversy that has waxed furiously around the implementation of the EEC Directives on the inspection of poultry meat and hygiene standards to be observed in poultry slaughterhouses, cutting‐up premises, &c, appears to be resolved at last. (The Prayer lodged against the Regulations when they were formally laid before Parliament just before the summer recess, which meant they would have to be debated when the House reassembled, could have resulted in some delay to the early operative dates, but little chance of the main proposals being changed.) The controversy began as soon as the EEC draft directive was published and has continued from the Directive of 1971 with 1975 amendments. There has been long and painstaking study of problems by the Ministry with all interested parties; enforcement was not the least of these. The expansion and growth of the poultry meat industry in the past decade has been tremendous and the constitution of what is virtually a new service, within the framework of general food inspection, was inevitable. None will question the need for efficient inspection or improved and higher standards of hygiene, but the extent of the