Causes of spoilage.

TM 38-400/NAVSUP PUB 572/AFMAN 23-210 MCO 4450.14/DLAM 4145.12

change in consistency and texture (softening).

ture, humidity, care in handling, protection from

Emulsions such as canned cheese and butter, prepared

weather, quality of the food when received, and the

mustard, and mayonnaise may be broken (separated) by

packing. Safe storage periods become very uncertain at

freezing although the food is not spoiled.

extremes of temperature and under combat conditions.

The fact that subsistence has been on hand up to the

(b) Heat (high temperatures). A high

limit of the "safe" storage period does not mean that the

temperature over long periods of time is very

subsistence should be surveyed but should be

detrimental to the keeping of almost all food products.

consumed as soon as practicable. Subsistence which

High storage temperature encourages bacterial growth,

has been on hand beyond the safe storage period

mold growth, and insect infestation and is particularly

should be inspected carefully for spillage, leakage, or

dangerous when accompanied by high humidity.

other damage and, if still good, issued as soon as

Chemical action is accelerated, causing rancidity in

possible; such items will be given priority of issue over

many items; action of the food acids naturally present

newer stocks.

within the cans is accelerated, resulting in pinholing,

c. Causes of spoilage.

blackening of the interior, and hydrogen swells. High

temperature is the chief cause of accelerated spoilage in

(1) Age. All foodstuffs are subject to varying

canned foods and should be controlled when possible by

degrees of natural deterioration; this deterioration is

providing adequate ventilation.

inherent in the food itself. It should not, however, be

confused with the action of micro-organisms, chemical

Flour and associated products (barley, cereals,

agents, or other outside agents. Such facts compel an

cornmeal, cornstarch, cracker and biscuit, hominy,

observance of the basic principle of storage that the

noodles, oats, rice, spaghetti and macaroni, tapioca, and

oldest lots of the item always should be used first,

uncooked wheat) are subject to insect infestation,

except under conditions indicated in a(1l) above.

particularly at high temperatures. Flour and cereals will

absorb odors and should be kept away from subsistence

(2) Insects (roaches, flies, weevils, and

or materials giving off distinctive odors. Cocoa will keep

moths). Insects can cause great damage to stored food,

years under cool, dry storage conditions. The formation

attacking both natural and manufactured food. Food

of white "bloom" (described as a "whitening" or "graying"

stored at temperatures between 60 F. and 900 F is

due to storage under fluctuating temperatures) has little

especially attractive to insects. Infested supplies must

or no effect on the flavor of cocoa. Long periods of

be segregated and if not too heavily infested, may be

storage at higher temperatures may cause mustiness or

"reconditioned" for use.

Cornmeal, especially, is

rancidity. Cocoa does absorb moisture and odors;

susceptible to insect infestation and rancidity. Insect

therefore, cans should be kept tightly closed. Roasted,

repellents should be used carefully so as not to

ground coffee rapidly develops a weak and stale flavor.

contaminate the foods or cause damage by the

If coffee is not hermetically sealed, it will absorb odors

absorption, by the food, of the fumigant or insecticide

affecting the flavor.

flavor. Roaches and flies not only contaminate the

foods, but may spread disease. (See chap 3, sec IV for

(c) Moisture (humidity). High humidity

information on pest management.)

is detrimental to stored subsistence in many respects

(i.e., accelerating the growth of bacteria and molds

(3) Rodents (rats and mice). Rodents not

promoting insect infestation and causing mustiness in

only physically destroy food by feeding, chewing, and

flour, rice, and similar foods). High humidity causes

cutting the bags for nests or nesting material, but also

products which readily absorb moisture such as sugar

contaminate food with their excreta and hairs. Rodents

and salt to cake and become hard. Tea will absorb odors

are carriers of filth and disease; the importance of

and high humidity causes it to become musty and sour.

controlling these pests is evident. The most effective

It should be emphasized that dehydrated products are

method of control is to prevent entry of these animals.

perishable and should not be handled or stored

(4) Physical environmental factors.

carelessly. Such products are subject to moisture

(a) Freezing. Dry products such as

absorption, insect infestation, and mold. A loss of flavor

grains, flour, sugar, starch, cereals, and dehydrated

and discoloration (darkening) will occur with age; this

foods, ordinarily are not injured by freezing. If foods

action is progressive and is accelerated at high

containing relatively large amounts of water such as

temperatures. Dried vegetables and fruits are subject to

canned products are frozen, the usefulness and

in- sect infestation and molding (particularly fruits) and

palatability of such products have not been harmed.

should be inspected at frequent intervals.

However, the physical appearance may suffer due to

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