THE CHEMISTRY OE FOOD

A man may eat his fill and yet be hungry. It is not the quantity but the proper quality in food that satisfies. It is not only true that what is one man's food is another's poison ; but it is also true that what is food at one season of the year, at one jieriod of life, or in one climate, may be poison to the same individual at another season or age, or in another climate. The inhabitants of the tropic subsists and thrives on fruits on which the Ice- lander would starve; while the blubber and oil that makes up the diet of the inhabitants of the frozen zimcs would be fatal to those who live under the burning sun of the equator. Even the same person requires a fruit diet in the tropics, and one of fats in the north region. The child requires food made up <d different elements from that which best suits the adult ; and the diet of a laliorcr in the open air must differ from* that of the brain-worker, who takes little exercise, and whose work makes heavy draughts on the nervous system.

No one has mastered the art of cooking who does not know something of the chemical elements of foods, and the purpose they serve when taken into the system. It is particularly important that those who are compelled to practice rigid economy should know just what foods will best supply the real needs of the family, and how the most real nourishment may be had for their money.

An adult takes into the system daily, through lungs and mouth, eight and a quarter puumls of dry food, water, and air necessary for respiration. The same amount is given off as waste through the pores, lungs, kidneys, and intestines. Life and activity consume this amount as fuel just as a lamp consumes oil. Every moment, every breath, every heart-beat, every thought burns up a cf^rtain amount of fuel-material, and if the supply is not forth- coming, the machinery stops and death ensues. The better the oil the more perfect the light ; and the more perfectly the food is adapted to its wants, the more vigorous the body, and the more perfect the working of its intricate uuK'hincrv of muscle, nerve, and brain.

THE CHEMISTRY OF FOOD. 1065

Food is first masticated and then digested. In mastication it is not only moistened with saliva, but acted upon chemically in preparation for the more vigorous and thorough work of the stomach. It is a mistake to sup- pose that water or any of the various drinks taken at table are a substitute for saliva. They not only do not prepare food for the stomach, but force it into the stomach unprepared, and, besides, retard digestion by delaying the process until the water can be absorbed into the blood. For these reasons drinks should precede or follow a meal. Crusts of bread and hard and firm food is wholesome, principally because it must be thoroughly masticated be- fore it can be swallowed.

When the food reaches the stomach it rouses into action, the gastric juice pours from hundreds of little points, the food is diluted and the more solv- ent parts dissolved, to be taken up by the thousands of little mouths which honeycomb the surface, and carried into the circulation to repair the waste of tissues. Tlie oily portions of food, and such as do not yield to the action of the gastric juice, pass on and are subjected to the influence of the bile and pancreatic fluid, until all that is of value is absorbed, while the waste is rejected and passes off.

This much of the digestive process needs to be known to make clear the why of certain processes in cookery. As the juices of the stomach only act on the surface of the food which passes into it, it is easy to see why light bread is more wholesome than heavy. The gastric and other juices can act only on the outside surface of a heavy lump of dough ; but when made into light and porus bread, the outer surface is not only vastly increased but the juices pour through thousands of avenues, and penetrate ami act on eveiy part. If the frugal housewife knew this, would she set the heavy, soggy loaf of bread before her children "to save it?" Many a mother ignorantly gives her children a stone when it asks for bread.

Fats of all kinds do not digest in the stomach. The gastric juice mingles with but does not dissolve them. It is only after they have passed on and become subjected to the action of the bile and pancreatic fluid that they are taken up and made available as carbon for lung combustion. Fats, uncoiv- hined with other substances, act as emetics or cathartics and not as food. It is only when combined with other food that they are capable of being taken u}) by the absorbing vessels, and made to act as fuel to the sj^stem. A half pound of crude lard, unmixed with any other substance, would be rejected, but when thoroughly and skillfully mixed into a flaky crust will not derange the stomach, and will be assimilated and utilized. Remember that the use of more fat than can be perfectly blended, or any carelessness or imperfection in the process, is sure to produce indigestion and work mischief.

Foods differ in the time required for digestion. Some fruits refresh in- stantly, the juice being at once absorbed into the circulation. Some meats and vegetables yield almost immedia4;ely to the action of the gastric juice, and pass into the circulation. Others require a long time for digestion. The more subtle and delicate flavors and parts of food yield first ; then the gluten of the flour, the curd of the milk, the fiber of the flesh, reinforce the blood and supply muscular waste, while, later, the oily and sugary portions are worked over to repair waste or furnish fuel to keep up the heat of the body.

Food has chiefiy two offices to perform ; the repair of muscular waste, and the supply of the body with fuel to keep its heat up to 98*^. Each of these is indispensable to health and strength. The chief part of what we eat is used by the lungs for fuel ; the rest, except small portions of minend substances, such as lime, potash, sulphur, etc., goes to the prcduction of muscular and brain force. The great secret in the preparation of food that

106G THE CIIKMISTRY Of FOOD.

will prolong life and maintain a high state of health, is to adapt it to the peculiar conditions of those to be fed, — age, occupation, climate, and season to be considered. Variety of food is nearly always at hand ; knowledge only is necessary to choose that best adapted to present needs.

The heat of the bod\' is produced by the action of the lungs, which tises uj/the h('at-pr<)diicing|f<jod, as action of muscle or brain consumes the muscle- making material. Tile former is non-nitrogenous ; the latter nitrogenous. Foods may be divided into three groujjs ; the nitrogenous, in whicli nitrogen is the chief element, and which feeds muscle only; the non-nitrogenous, chiefly carbon, which produce heat only; and those in which both are united.

It has been proved by chemical analysis that the body reipxircs four to five ounces fur heat to one for muscle, and this gives us the key to the proper jiroportion of the elements in food, varying slightly of course, with seasons, climates, occui)ations, and ci^nditions.

The suljstaiice riclu-st in nitrogen, the muscle-making element, is albu- men, found in its most perfect form in the white of an egg. The lean or red parts of beef, mutton, venison, and chicken contain nearly as great a per- centage, as well as grain, pease, and beans. If muscles only were to be fed, these would be nearly perfect foods, but for one ounce that goes to muscle, live ounces must go to heat, and this calls for carbon.

The carbon neede<l to keep up the bodily heat comeschietly from starch, which is abundant in the vegetable kingdom. Grate a potato and wash in a tiuccession of waters, allowing the sediment to deposit each time, and a floury substance will appear, })erfectly white, and dry and crispy to the touch. This is starch, and consists of round grains, too small to be seen by the eye. One-half of the bulk of dry starch is carbon ; the remainder is oxygen and hydrogen in exactly the proportion as in water; and in that wonderful laboratory, the stomach, the carbon is elminated from the starch, and the oxygen and hydrogen combine to form water.

The starch made from wheat is seldom used as food. Sago, Tajnoco, and arrowroot, so much used for pmlilings, are almost pure starch, with sliglit coloring matter taken fron\ the material. Corn starch is less agreeable in flavor, and makes a less tinii jelly when cooked. These desert dishes are easily digested, and contribute c-irbon, but do not feed muscle, except as they are cond)ined with milk, eggs, etc., in cooking, which contain a little nitro- gen and a good deal of carbon. The food, then, is not adapted to a working man or to growing children, who need to have their muscles fe<l. For persons of sedentarj- habits, especially for the aged, whose feeble resi)iration needs a large .su})]dy of carbon to keep up lieat, they are valuable because easily digested. For others they are of value only to supplement muscle-making food as adessert.

The following table (Prof. Yoemans) gives the proportion of starch in common grains .

Pek Cent St.vkch.! Pek Cent Starch.

Kice Flour, - - - 84 to 85 Barlev Flour, - - G7 to 70

Indian :Meal, - - - 77 to 80 Rve Flour, - - - 50 to (U

Oat Meal, - - - 70 to 80 Buckwheat, - - ry2

Wheat Flour, - - - 30 to 77 Pease and Beans, - - 42 to 4.? Potatoes (75 per cent water) 13 to lo.

The large variation in wheat flour is due to the process of grinding. Va- rieties of wheat (mly vary alnuit five per cent, but the old process of making tine white Hour, used onlv the nuddle or starchy parts of the kernel, reject- ing the gluten (nitrogenous and muscle-feeding.) The whitest and highest- ]»riced flour was, therefore, less nourishing, containing the largest per cent of starch. Modern invention has, however, reversed this, and the best "new

THE CHEMISTRY OF FOOD. 1067

process" flour contains the largest proportion of gluten. The old argument in favor of Graham, that it contained a larger proportion of nitrogen, and better supplied the body with muscle-making material, no longer holds good. Analysis shows that the best "new process" flour and Graham are almost identical in these elements. The only advantage left for Graham is the action of the coarser particles of bran (the outer shell and indigestible) on the coat- ings of the stomach, which is often salutary, but sometimes injurious to tlie delicate membranes. When flour and bread made from it contains one part nitrogent to four of carbon, it is nearly perfect food, and will sustain life.

The substance which is of next importance in supplying carbon to the body is oil (which is chiefly carbon). The oils used for food are butter, lard, and the fat of beef. Other oils, used sometimes in cooking, are nearly iden- ticle with these. They contain about eighty per cent of carbon, butter hav- ing the least. In grains, oil varies, being nine per cent in corn meal, six in oatmeal, three and a half in rye, and one to two in wheat. Oils and starch serve the same purpose in the digestive process ; both are useful to supply carbon; neither nourish muscle. Starch is easy of digestion, requiring one hour, while butter is converted into chyme in three and one-half, nmtton-fat in four and a half, and beef-fat in five and one-half hours. This furnishes the best of reasons why fats should be sparingly used, especially in warm and moderate weather, when a sufficient supply of carbon is easily secured from vegetable foods. Besides, it is a well established fact that 'excessive use of fats in cooking cause an excessive secretion of bile, and this in turn, causes a sensation like hunger and an increase of saliva. This is mistaken for real hunger. ]More food is taken, and indigestion, and later dyspepsia result. An eminent authority says : "I believe it will be found the' offend- ing ingredient in nine-tenths of the dishes that dii^turb weak stomachs." Dyspeptics need to reject not only foods in which fats are mixed, but those in which they are the natural element, such as the yolk of eggs, liver, milk, rich cheese, etc. Yolks contain twenty-eight per cent of oil, and milk over three per cent. One condition only calls for .the use of fats in daily diet : Long continued exposure to excessive cold. One

The best bread for cold weather is that containing most oil . Corn breach ranks first, oatmeal next, rye third and wheat last. Of course comparativeh few are exposed to the rigors of winter in civilized life, and brief exposure to cold is ofl'set by an increase of clothing, and ordinary diet furnishes a plentiful supply of carbon. For woodmen, soldiers, sailors, pilots, travelers, railroad men, and others exposed to long, cold storms, especially when they can not exercise freely, should eat liberally of fat beef, yolks of eggs, and butter. Butter is the least objectionable of fats. Fat from salt pork and smoked bacon is less injurious than that from fresh pork. Beef fat is also much more W"holesonie than lard. Above all, let the cook remember that oils are physic, and next to poison, if not blended with substances which contain large quanties of starch, such as rice, mealy potatoes, and bread made of fine wheat flour. An ounce of lard and a pound of flour thoroughly blend- ed in a loaf of bread is digestible, but the same amount added to corn meal (already rich in oil) would be fit food only for a Greenlander. The proper proportion of oil in food of ordinary circumstances is illustrated in milk, which contains three and one-half parts of oil in one hundred.

The next important element which supplies carbon is sugar, w^hich is contained in greater or loss quantity in all vegetable substances, and largely (five to six and one-half per cent) in milk. Sugar contains forty per cent car-

1068 THE CHE>nSTRY OF FOOD.

hon, the rest water. It seems to be first converted into fat, and then used in respiration. In moderate quantities it has no injurious effects. A part of su^ar as ordinarily eaten passes into lactic acid, and aids digestion, but if too much is produced digestion is retarded.

There are too kinds of sugars in commerce — cane and grape. The former is rnadc from cane, maple saps, beets, corn-stalks, etc. ; the other from plants ■whifh have an acid juice. Cane sugar contains twelve parts carbon to eleven of water ; grape sugar twelve of carbon to fourteen of water. Sugars are changed by fermentation into carbonic acid and al<;ohol, but grape sugar is most liable to such fermentation — cane sugar first becoming grape sugar by chemical combination with water. Pure cane sugar remains perfectly dry and unchanged in the air, while grape sugar attracts moisture, and becomes mealy and damp. Cane sugar dissolves more readily in water than grape, and hence tastes sweeter. Two pounds of cane sugar sweeten as much as live of grape. These facts give a hint to housekeepers of great value. Grape sugar, whicli is worth only two-fifths as much as cane, is used largely to adul- terate the latter. The fine, floury "powdered" sugar is largely grape sugar, and is not only of much less value, but deteriorates more rapidly than pure cane sugar. Brown sugar, after standing for some time, absorbs water from the air, and becomes grape sugar. It is, therefore, the best economy to buy the best white granulated sugar.

There is another element of food which does not feed muscles, vegetable jelly, called pectine. This and pectine acid particularly abounds in fruits and berries, By tlie processes of ripening, the vegetable acids which are enclos- ed in little cells, burst out and diffuse through the mass of fruit, and manu- facture pectine or jelh\ Heat produces the same effect as ripening, and cooking is, in fact, only a rapid process of ripening. The jelly, when com- bined with sugar, goes to make up a variety of delicate articles, such as jellies and marmalades. They are nourishing, principally on account of the sugar they contain, but are easily digested, cooling and delicious. It should be mentioned that nearly all fruiits are rich in sugar, — a ripe peach containing as much as an equal quantity of cane juice.

There are some other substances which appear in less quantity in foods which seem none the less essential to health and life. One of these is phos- phorus, which is the element of brain and nerves, and is wasted by mental activity and nervous excitement. The brain-worker demands a diet rich in phosi)h()rus, and in sucli a form as to be easily assimilated. The food that l)est sustains a laborer in the open air is not the best for those who live among the excitements and exhausting demands on the brain, that are the rule in city life. For the latter, eggs, iriost kinds of fish, oysters, lobsters, crabs, game, cheese, and among vegetables the potato; aiid these foods are just what are craved by city people'

Another element is sulphur, which is required in the growth of bone and cartilage, the hair and nails. Of this there is so much in the yolk of an egg that silver is blackened by contact with it. Curd of milk and "cheese are also rich in sulphur.

Iron is always present in healthy blood, and its absence — paleness — is an indication of illness. Most articles of food contain iron ; in the juice of flesh, in eggs, and in milk it is abundant. Lime and salt are also ingredients in all food, the former making bone, and the latter playing an important part in the creation of the digestive juices. Lime is found in all grains, particularly in wheat and in milk, in form of subphosphates. Bread and milk are for this reason an excellent diet for growing children, as they supply not only heat and muscle, but lime that goes to supply the growth of bone. .Salt also exists in many articles of food.

I\Ien and races grow in proportion to their skill in combining heat and muscle-producing foods. The hardy Scotch use oatmeal largely, which is

THE CHEMISTRY OF FOOD. 1069

rich in nitrogen. The Irish, who endure a large amount of hard labor on cheap fare, eat potatoes, oatmeal, cabbage, and milk, while the lime and phosphates are said to be derived from the ''hard" water impregnated with lime. The English add bacon (heat-producing) to beans, rich in niti'Ogen, and to rice, which abounds in starch (carbon), and milk and eggs, which feed muscle. The Italian eats macaroni, which is principally starch, with cheese, rich in nitrogen. The use of chemistry in cooking is to teach how to supplement one kind of food by another which contains the essentinl elements which the first lacks. For instance, venison contains fifteen per cent nitrogen to fifty-two carbon, or as one to three and a half, while the ratio should be one to four or five. To make it perfect and satisfying food. M'e have only to supplement it with something rich in carbon, as wheat bread, oatmeal, potatoes, or rice. A farmer's dinner of salt poric and cabbage is nearly perfect for an out-door laborer in cold weather. The cabbage is rich in Tlitrogen and the pork in carbon. It is a proper dinner dish, because it requires four and a half hours to digest, while a supper may be made on venison, which is digested in an hour. Beef has fifteen per cent of nitrogen, but is not so easily digested as venison, and is fit only for a breakfa.st or dinner dish. Wheat bread does not contain nitrogen enough for a workingman's diet, and butter eaten with it does not supply the lack. Some kind of lean meat is needed to make per- fect food. The more active the life out of doors the nearer can health be sustained on a diet of lean meat only. Beans contain, next to meats, the most nitrogen, and are excellent food for

Milk contains all the important elements of food ; yet adults need solid food. Add to milk eggs, rich in nitrogen, rice and sugar, rich in carbon, and you have a nutritious dish, easily digested.

Butter-milk is a wholesome drink, particularly in summer, as the nutri- tive power of the milk is but little reduced by the removal of the butter, while the sourness, due to the formation of lactic acid, aids digestion.

Eggs contain a great deal of carbon, and are, for that reason, good food for cold weather. They are too concentrated for exclusive diet, and should be eaten with coarse food, or that which is composed largely of starch.

In making cakes, the oil of the yolks of eggs used makes the perfect blending of lard or butter impossible, and hence unwholesome. For this reason sponge cake, which contains no butter, is less objectionable.

Breads difi'er but little in these elements. Corn meal contains more oil and less niti-ogen than others, and oatmeal is richest in nitrogen. The easy blending of the elements, and the tough gluten of wheat, make it the most aA'ailable grain for bread. Wheat bread alone will support life longer than any other food except animal flesh. The proportion of nitrogen to carbon is one to five, which is nearly correct for a sedentary person. For active, out- door life more nitrogen is needed, and is best supplied by lean meats.

The nutritive qualities of animals difl"er but little. Wild meats digest more easily than tame, though the time required varies with the age and condition of the animal. Flesh is a stimulating diet because it is force-giving and muscle-feeding. The animal has gathered from various sources and concentrated in its flesh the constituents which best meet the wants of our bodies in the most available form.

Applying the knowledge of the wants of the body, and of the elements of food to a bill of fajre, and a wholesome breakfast demands strength-giving

1070 THE CHEMISTRY OF FOOD.

and muscle making food. Nothing is more quickly available than beefsteak, and it is most digestible broiled. It is a diet for real workers. Eggs are nu- tritive, but less stimulating. These provide for the muscles. For heat, starchy food is demanded, but bulk is not desirable for breakfast after a long fast. Bread and cakes of wheat flour are best for the purpose, and fruits, raw or cooked furnish the mild vegetable acid, which aids digestion If cof- fee is taken at all, breakfast is the time, so that the stimulating effect may ■ ])ass away before the hour of rest comes. An infusion of genuine coffee, not a decoction, is not injurious in the morning to most persons, and is beneficial to those exjjosed to changes ot temperature.

Nothing appeases the appetite sooner than the juice of flesh. The barley gives a color and flavor. Following soup is roast beef, which feeds the muscles, and after it come the puddings, which abound in carbon, to give the fuel necessary to keep up the animal heat. Last comes fruit to aid digestion, with its agreeable acids. In summer le.«s carbon should appear on the bills of fare, and blanc-manges, creams, fruit puddings and pies, berries, and ripe fruits should make up the desserts.

In making a feast, the wise hostess would consider well what has been the employment of the guests. A party of fox-hunters, or wood-clioppers, or surveyors, would require an abundance of meats, but a collection of artists and scholars would relish better a variety of delicacies and novelties A sleighing party will devour carbon, but those wIkj have sweltered under a July sun long for cooling fruits and the leanest of meats. The time when a feast is given should decide whether food, easy or difficult of digestion, should appear on a bill of fare, though such consideration for the health of guests is hardly to be expected of the average hostess.

A table of relative proportions of nitrogenous to carbonaceous elements in food, deducted from above hints may be of aid to many and has been kindly given us by a physician.

or Nitrog. Carbonaceous.

Lean beef 1 c o

Eggs 1 1.5

Pease 1 2.7

Beans 1 2.7

Lentils 1 2.4

Milk 1 3.6

Fat Beef 1 o.O

Oatmeal 1 <j. 1

Wheat meal or Bread 1 7.0

Indian meal 1 7.7

Rye meal 1 W.8

Potatoes 1 10.7

Carrots 1 11..-)

Barlev meal 1 12.7

Rico." 1 13.0

By tlie above table it will be seen that wheat meal is the food which of all single substances the most perfectly meets the requirements of the sj'steni, containing exactly seven parts of the carbonaceous elements to one of the albuminous. Beef and eggs are deficient in the cai'bonaceous elements. Potatoes and most other vegetables, and rice, are deficient in albuminous elements. Oatmeal has an excess of the albuminous elements. JSy combin- ing food substances which arc deficient in one class of elements with those in wiiicii the same class is in superabundant proportion, the two classes of ele- ments may be furnished to the system in just the right proportion. For in- stance, lean lieef, eggs, pease, beans, milk, or oatmeal may be used with

THE CHEMISTRY OF FOOD. J 071

potatoes, rice or other foods deficient in albuminous elements. It is for this reason that the Irish or Scotch laborer by instinct combines with his potatoes, oatmeal porridge or buttermilk. The following gives the proper proportion of different foods necessary to furnish the right amount of albuminous ele- ments.