1. Ferments for predigesting foods at home.

2. Predigested proprietary milk foods, either alone or in combination with starch.

3. Predigested proprietary meat preparations.

4. Malt and malt extracts.

5. Malted foods, in which starch is partially changed or completely changed into soluble carbohydrates. " Invalid foods".

I. Ferments

In the preparation of predigested foods two classes of agents have to be relied upon: the action of the digestive ferments, of which pepsin and pancreatic extract are best known, and which act upon the proteins and carbohydrates of the food; and secondly, the vegetable ferment diastase or malt, which has the property of converting starch, an insoluble substance, into the soluble sugar maltose.

The digestive ferments find their use in the following directions - (a) as therapeutic agents, being used as remedies for indigestion; (b) as peptonising agents, for the artificial digestion of food. These ferments are obtained by simple infusion of the fresh gland or the secreting membrane, and in the proper media behave in the same manner as the natural juices. They may be dried and made into powders. These digestive ferments possess enormous energy, being capable, even when only in an infusion, of converting into solution many thousand times their weight of alimentary substance. Pepsin is found only to be active in an acid medium, pancreatic ferments in neutral, alkaline, and feebly acid solutions. The dried powders are preferable to the fluid preparations, being more constant in their action. An additional point of importance is that the dried powders hardly effect the flavour of the food treated, while the infusions all tend to impart their peculiar repulsive taste to the food.

Pepsin can be administered by the mouth to aid feeble digestion or to relieve indigestion, but it is not available for peptonising food for the sick, its action being restricted to albuminous substances in an acid medium. This has to be remembered, since the words peptonised and peptone are erroneously associated with pepsin. Practically all pre-digestion of foods is done with pancreatic ferments. Pancreatic extract contains a ferment capable of transforming proteins into peptones like pepsin, but it acts in a neutral or alkaline or faintly acid medium; another ferment, trypsin, has a special power in digesting milk; there is in addition a starch-digesting principle.

Peptonised foods should only be employed when it is necessary to assist the digestive organs for a time by giving the alimentary canal some degree of physiological rest.

They are indicated in many acute diseases associated with impairment in the gastric functions, such as gastric ulcer, cancer of the stomach, and some severe constitutional diseases in which irritability of the stomach is a prominent feature. Some of the so-called humanised milks are prepared by partial peptonisation or pancrcatisation of the milk-proteins.

Pepsin in the form of pepsin powder or tablets, Pepsencia (Fairchild's), or Liquor pepticus (Penger's) is administered directly after a meal, and is not mixed with the food before being swallowed, because, as already explained, to get it to act on the food the pepsin must be mixed with dilute hydrochloric acid, and this spoils the flavour of the food.

Savory & Moore have produced a saline essence of pancreatine, and saline essence of pepsin; these have an agreeable ketchup odour and flavour, and may be used with roast meat or fowl as a sauce, or a small quantity may be added to beef-tea, soup, or broth. In actually peptonising milk and foods by means of pancreatic ferments there are several reliable preparations that may be employed. Liquor pancrcaticus (Benger's), Allenbury's Extractum pancreaticum and peptonising powders, and Byno pancreatin are all reliable; the latter can be used either for peptonising food or can be taken with meals. Fairchild's "Zymine" powder and peptonising tubes are always reliable. Savory & Moore manufacture peptonising pellets, each weighing 5 grammes. This form of powder does not require a large excess of alkali, and the flavour of the foodstuff is hardly altered.

All these peptonising preparations give full directions for their use on their wrappings; in addition the following recipes may be given: -

Peptonised Milk

1 pint milk.

1/4 pint water.

2 teaspoonfuls Liquor pancreaticus. 20 grs. (1/2 small teaspoon) bicarbonate of soda.

Allow the milk to stand. Skim off the cream. Dilute the skimmed milk with 1/4 pint of water, and heat to a temperature of 1400 F. Mix with the warm milk the Liquor pancreaticus and 20 grs. of bicarbonate of soda. The mixture is poured into a covered jar, with a tea-cosy over it, and put near the fire. Let this stand for one and a half hours. Bring the mixture to the boil for two or three minutes to arrest any further fermentative action, which will make the milk unpalatable. Now add the cream that was removed, and it is ready for use.

When peptonised by the cold process described below, the milk has no taste or evidence of the presence of the peptonising agent, and is especially suitable for dyspeptics.

Method

Mix the peptonising agent in cold water and cold milk as above, and immediately place the bottle on ice without subjecting it to any heat. When needed, pour out the required portion, and use in the same manner as ordinary milk.

It is recommended to try the milk by the cold process in those cases in which food is not quickly digested, and in which the digestive functions are impaired or even practically suspended. It has been found in many such cases that the peptonising principle exerts sufficient action upon the milk in the stomach to ensure its digestion and proper assimilation.

Effevescent Peptonised Milk

Put some finely crushed ice in a glass and then half-fill it with Apollinaris, Vichy, or carbonated water as preferred, and then quickly pour in the peptonised milk and drink during effervescence. Peptonised milk may be made agreeable to many patients by serving with a little grated nutmeg, sweetened, or flavoured with a little brandy.

Peptonised Gruels are acted upon by the ferment, the starch being transformed into sugar, and the albuminoid matters are peptonised.

The gruel may be made from any farinaceous article in use - oatmeal, Quaker oats, etc. The gruel should be thoroughly well boiled. It is placed in a covered jar when it is below the temperature of 140°F., the pancreatising agent is added, and the jug is covered and kept warm as before. After standing two hours, boil the mixture for five minutes, and then carefully strain.

Peptonised Milk Gruel

This was a favourite preparation of Sir W. Roberts. It is an artifically digested milk, and forms a complete and highly nutritious food for weak digestions.

A thick gruel is made from farinaceous material (see p. 296). To the boiling gruel add an equal quantity of cold milk. This will then have a temperature of about 1400 F. To each pint of the milk gruel add 3 teaspoonfuls of Liquor pancreaticus and 20 grs. of sodium bicarbonate (or other peptonising agent). Let it stand covered in a warm place for two hours, boil for five minutes, and then strain. The peculiar flavour of predigested milk is quite masked by this process, and most invalids will take it without the least objection.

Peptonised Milk Lemonade

Juice of 1 lemon.

1 gill peptonised milk.

I gill effervescing water.

1 tablespoonful of sugar and rice.

Fill a small tumbler one-third full of crushed ice, add the water, lemon juice, and the sugar to the ice, and fill up the glass with milk.

Peptonised Milk Punch

Take a small tumbler and fill it about one-third full of crushed ice, pour on to this a tablespoonful of St Croix rum, and half a tablespoonful of brandy; then fill the glass with peptonised milk, stir it well, sweeten to taste, and sprinkle over the top of the mixture a little grated nutmeg.

Peptonised Meat

Add 4 ounces of minced meat to 1/2 a pint of water, and gradually bring to the boil. Then add 1/2 a pint of cold water, so as to reduce the temperature to about 140o F., and add 30 grs. of Zymine or other peptonising agent, and 20 grs. of bicarbonate of soda. Keep warm for three hours and the meat will be peptonised.

Peptonised Meat, Broths, And Teas

1/2 lb. lean beef, finely minced. 1 pint water.

1 tablespoonful Liquor pancreaticus. 20 grs. bicarbonate of soda.

Mix together and simmer slowly for one and a half hours; when it has cooled down to 140 F., add Liquor pancreaticus; keep it warm under a cosy for two hours; occasionally shake it up, then decant off the liquid portion and boil for five minutes.

This has a relative value in nitrogenous materials almost equal to milk. The tea can be flavoured with celery seed or vegetables, or thickened with sago, breadcrumbs, etc. (see P.75).

Peptonised Soups, Blancmanges, And Jellies

With a little ingenuity a variety of peptonised dishes can be obtained. There is no difficulty in doing this if it is always remembered that any peptonised fluid after standing at most two hours must be boiled, in order that the action of the ferment may be arrested. For the making of soups, use peptonised gruel (p. 173) instead of water. For the making of blancmanges, peptonised milk is added to the cream. For jellies, mix the Liquor pancreaticus with gelatine in the proportion of 2 teaspoonfuls to the pint, allow it to stand for one and a half hours in a warm place, and then check the further action by boiling.

Peptonised Oyster Soup

Take half a dozen large oysters with their juice, and 1/2 a pint of water. Heat in a saucepan until they have boiled briskly for a few minutes. Pour off the broth and set aside.

Mince the oysters finely, and reduce them to a paste with a potato masher. Place the oysters in a jar with the broth that has been set aside, and add Liquor pancreaticus 2 teaspoonfuls, sodium bicarbonate 15 grs. Let the jar stand in hot water or in a warm place for one and a half hours, then pour into a saucepan, and add 1/2 a pint of milk. Heat over the fire slowly to boiling point, flavour with salt and pepper, and serve hot. Any undigested oysters may be strained out. The milk will be sufficiently digested during the few minutes which will elapse before the mixture boils, if heated gradually.