Food processing

“ When by these or other means we convert vegetable tissue into dextrin and sugar, as it is naturally converted in the ripening pear, and as it has been artificially converted in our laboratories, we shall extend our food supplies in an incalculable degree. Swedes, turnips, mangold-wurzels, &c., will become delicate diet for invalids; horse beans, far more nutritious than beef; delicate biscuits and fancy pastry, as well as ordinary bread, will be produced from sawdust and wood shavings, plus a little leguminous flour to supplement the nitrogenous requirement. ”

“ The importance of pure food can not be overestimated. The surest way to get it is to do your own grinding, thus having the article freshly ground as you use it, and avoiding the danger of injurious adulterations. This mill is adapted to grinding or pulverizing any of the following articles:—
Coffee, peanuts or nuts of any kind, all wet or oily substances, corn meal, cracker dust, bread crumbs, cracked wheat and oats, horseradish, and cooked meats, spices, herbs, and roots, vanilla beans and pods when mixed with sugar and ground together for flavoring ”

“ The addition of a small quantity of a food rich in oil and albuminous substances to the ordinary kinds of feed, which contain a large quantity of vegetable fibre or woody matter, more or less indigestible, but nevertheless indispensable to the herbivorous animals, their digestive organs being adapted to a bulky food, has been found highly advantageous in practice. ”

“ It is proper to remember that the white flour from which our bread is chiefly made, and which is deemed the staff of life, is a purely artificial product—a selection from that perfect food combination which exists in wheat. A competent food chemist has compared the regular milling processes to one by which the fat part of an ox should be saved for food, and the lean part—the albuminous or nitrogenous portion—discarded and given to the dogs. ”

“ As has been pointed out, it is not the mere presence of micro-organisms that causes the spoiling of food, but their constant growth. Therefore, to keep milk from souring, meat from spoiling, bread from molding, canned fruit from fermenting, and so on, it is necessary to know what will prevent the growth of these minute organisms. Different foods require different treatment. Some foods must be kept very cold, some must be heated or cooked, others must be dried, and to others must be added preservatives. ”

“ From the number of animals under experiment, and the well-planned and thorough methods of investigation, in all departments of the experimental work, the results obtained have been of great value, not only from the light thrown on many of the obscure processes of nutrition, but also in laying a foundation for a consistent system of feeding, in which the relations of the food consumed to the special animal products obtained, and to the value of the manure produced, as an incident of the process, are clearly traced. ”

“ White of egg and lean meat are almost pure protein and water. Proteins are most abundant, as we should expect, in those plants which are richly supplied with nitrogen; peas and beans, and in grains and nuts. Fats, which are melted into oils at the temperature of the body, are represented by the fat in meats, bacon, pork, lard, butter, and vegetable oils.
Water.—Water is, as we have seen, a valuable part of food. It makes up a very high percentage of fresh fruits and vegetables; it is also present in milk and eggs, less abundant in meats and fish, and is lowest in dried foods and nuts. ”

“ By the substitution of a little cheese and an orange for the oatmeal, a meal containing about the same fuel value and proportion of protein could be arranged, and it would certainly appeal more to the appetite, and furnish better proportions of ash constituents.
In the construction of the menu for the day or meal, we must consider not only food values and time of day and combinations which shall be digestible, but flavor, color, texture, and temperature of our foods. The study of digestible combinations belongs to the science of nutrition. ”

“ The process of maintaining animals with suitable food for the production of milk or flesh is similar. The combination of flour, water, salt and yeast, by heat, first mild and then intense, into a loaf of bread is a good illustration of a change of qualities by rearrangement of the elements of a substance. ”

“ In the nutrition of both plants and animals large quantities of water are needed. The solids must be supplied in solution or dissolved in the assimilative processes, and this cannot take place without water, which also conveys the dissolved solids to the various parts of the economy, and in the case of animals removes waste materials. For the most part, water passes through the body unchanged, but a certain proportion unites chemically with the food materials and assists in their digestion. It is therefore not surprising that seven eighths of milk is composed of water. ”

“ Raw and Cooked Foods Compared.—Raw and cooked foods differ in chemical composition mainly in the content of water. The amount of nutrients on a dry matter basis is practically the same, but the structural composition is affected by cooking, and hence it is that a food prepared for the table often differs appreciably from the raw material. Cooked meat, for example, has not the same percentage and structural composition as raw meat, although the difference in nutritive value between a given weight of each is not large. ”

“ The lesson we should learn from this is that ordinarily if it is necessary to soak foods, such as beans, they should be cooked in the water in which they have been soaked. Furthermore, where possible, as it is with nearly all succulent vegetables, we should take the fluid in which the vegetables have been cooked as a part of the meal. If the vegetables are properly cooked, there will not be much fluid to take. To pour away the water in which vegetables have been cooked means that perhaps one-third of the food value and one-third to one-half of the valuable salts are lost. ”

“ I do not mean by this that the vegetable we should use shall be grass itself, or that grass should be one of the vegetables. We must, for our requirement, select vegetables that contain as much nutriment in a given bulk as our present mixed diet, but in doing so we encounter the serious difficulty of finding that the readily soluble cell wall or main bulk [178] of animal food—the gelatin—is replaced in the vegetable by the cellulose, or woody fibre, which is not only more difficult of solution, but is not nitrogenous, is only a compound of carbon, oxygen, and hydrogen. ”

“ For instance, boiling in water, which is probably one of the most common ways of cooking vegetables, is decidedly advantageous in some respects, but the water dissolves much of the soluble material, such as mineral salts, sugar, etc., found in the vegetables, so that unless some use is made of this water in the cooking of other foods, considerable waste results. On the other hand, steaming and baking permit no loss of food material, and so they should be applied to vegetables whenever it is desired to conserve food substances. ”

“ The staple grain feeds are corn, oats, wheat, barley and buckwheat. The grain by-products, bran, middlings and gluten feed, to which may be added corn meal, ground oats and ground barley.
Animal food of some kind is an essential to growth and egg-production. Skim milk and butter milk, fish scrap made from oil-free fish, beef scrap, fresh cut green bone and good grades of digester tankage are all excellent. But use only feeds of this character which are of prime quality. Oily fish, poor beef scrap and mouldy green bone will surely cause trouble. ”

“ The art of cookery, by exposing vegetable and animal substances to heat, has contributed to increase the quantity of the food of mankind by other means besides that of destroying their acrimony. One of these is by converting the acerb juices of some fruits into sugar, as in the baking of unripe pears, and the bruising of unripe apples; in both which situations the life of the vegetable is destroyed, and the conversion of the harsh juice into a sweet one must be performed by a chemical process ”

“ Modern science carries us a step farther and teaches us that cooking destroys lower organisms, such as harmful bacteria that may be present, and even animal parasites in meats.
We cook, therefore, to improve the appearance of food, to develop flavors, to render some foodstuffs more digestible and to destroy microörganisms.
We have at our command the following processes:
Heat direct from coal, charcoal, wood, or gas. ”

“ Let the proportions follow the example given in wheat, milk, and eggs, which have all the elements needed and in proper proportions. According to this rule, use unbolted flour rather than superfine. In selecting food, have reference to age, climate, and state of the health. Meals should be at least five hours apart, that the stomach may rest. Do not eat between meals, as it mixes partly digested food with the new supply, and impedes digestion. Do not eat too much, because it impedes digestion, and overtaxes, and thus weakens, the organs that must throw off the excess. ”

“ The eating of flesh tends to produce a distaste for mild vegetable foods, especially if uncooked. In process of time, not only flesh but vegetable foods, were more and more subjected to cooking and seasoning, or mixed with the flesh, blood or viscera of the animals killed. Next, food was manufactured to produce a still greater variety, to increase the flavour, or less frequently to produce an imagined greater digestibility or nutritiveness. Man has taken that which seemed most agreeable, rarely has he been intentionally guided by scientific principles, by that which is really best. ”

“ He can even subsist on every variety of these substances, under every mode of preparation, dried, preserved in salt, hardened in smoke, pickled in vegetable acids, &c.
The Author of Nature has so constructed our organs of digestion, that we can accommodate ourselves to every species of aliment; no kind of food injures us; we are capable of being habituated to every species, and of converting into nutriment almost every production of nature. ”

“ The preparation of food is of two kinds—public and private. The public consists in the ordinary modes of converting minerals and gases into vegetables, and vegetables into animals with milk, cream, cheese, flesh meat, and marrow-bones. ”

“ The proper adjustment of the relative quantities of the great groups of nutritive elements in the food is a matter the importance of which cannot be over-rated, for it is in fact the foundation of successful and economical feeding; and this will be readily understood if we consider what would be the result of giving to an animal a supply of food containing a large quantity of nitrogenous and a deficiency of fat-forming compounds. ”

“ When I come to the other constituents of vegetable food it will be understood that the changes effected in their cookery are but nominal, and that nearly the whole business of vegetable cookery consists in rendering the cellular tissue more digestible than it is in the raw state ”

“ Whatever may be the material, therefore, from which bread is made, when the artificial preparation is of that simple character which leaves the proportions of 25nutritious and innutritious properties, as nature combined them, and effects little change in the nutritious principles, and retains the natural requisition for the function of the teeth, and thus secures the proper chewing of the food and the mixing of it with the fluids of the mouth, and swallowing of it slowly, the artificial process militates very little, if at all, against any of the physiological or vital interests of the body. ”

“ When we enquire more minutely into the chemical constitution of the different alimentary materials, which promote the growth, support the strength, and renew the waste of our body, we find that animal substances are not suited to form the whole of 9our daily food ”

“ In vegetables, the absorption of food is thus regulated chiefly by the circumstances of heat, moisture, and light, under which the plant is placed, and by the consequent necessity which exists at the time for a larger or smaller supply of nourishment to carry on the various processes of vegetable life. According to this arrangement, nutrition is always most active when the greatest expenditure of material is taking place. ”

“ The principles above explained, therefore, shew that the value of any vegetable production, considered as the sole food of an animal, is not to be judged of—cannot, in short, be accurately determined—by the amount it may contain of any one of those substances, all of which together are necessary to build up the growing body of the young animal, and to repair the natural waste of such as have attained to their fullest size. ”

“ The composition of water had just been discovered, and he found by experience that a given quantity of solid food was more satisfying to the appetite and more effective in nutrition when made into soup by long boiling with water. This led him to suppose that the water itself was decomposed by cookery, and its elements recombined or united with other elements, and thus became nutritious by being converted into the tissues of plants and animals. ”

“ It is well known, however, that the mechanical state of the food has a most important influence on its nutritive value. Thus, for example, the presence of a large quantity of woody fibre protects the nutritive substances from assimilation, and seeds with hard husks pass unchanged through the animal, although, so far as their composition alone is concerned, they may be highly nutritive; and the loss of a certain quantity of many varieties of food in this way is familiar to every one. ”