*63071 Or3cl 729 STATE Food Spoilage (Causes and Prevention) 0 E; Prepared by Extension Nutrition Specialists, Oregon State University - COLLECTO.1 A diamond may be forever, but food quality is not. tamed until the food can be eaten. When we purchase or grow high quality food, we must SoGIVE FOOD CARE to keep it safe and to handle it in such a way that the good quality is re- maintain quality. General Rules for Food Storage 1.Handle food gently to prevent bruising or breakage fection is greater in sliced or ground food. or cutting of the outside skinas the case may be. Do not wait for leftovers or foods cooked for later 2. Take food home as soon as you can after shopping. use to reach room temperature. Refrigerate them Put perishable food in the refrigerator immediately. quickly in covered containers. 3. Be sure that sliced or ground food is well-cooked Freeze or refrigerate sandwiches and other foods and well-refrigerated. The chance of spreading in- that you plan to take on picnics or outings. Signs of Spoilage Foods spoil if we keep them too long, handle them All of the actions explained above will not harm us carelessly, or store them improperly. We may see if we eat the food. Mold growth and yeast growth on mold growing where it is unwanted. Fruit juices may food usually are not harmful to persons who have eaten become bubbly from the fermentation of undesirable food spoiled in this way. The vitamin content may have yeast growth. Off-flavors may develop and sometimes been altered, but the food is still edible. In some cases, the odor is objectionable. Cans of food may show mold growth is desirable, such as in making Bleu cheese. bulges both top and bottom. None of these things is Yeast growth is what gives the raising power in making desirable and we describe the food as spoiled. bread. Food Poisoning Food poisoning comes to us in three ways: Poison- looking into the matter more deeply, investigators found ing by chemicals, poisoning by poisonous plants and that the steaks had been grilled on an old refrigerator animals, and poisoning by microorganisms and their shelf. Tests showed that the shelf had been plated with products. cadmium, which melted under the high temperature of burning charcoal and stuck to the steak. Result: cad- mium poisoning. Many metal household products are Poisoning by Chemicals coated with cadmium. Do not use makeshift utensils of this kind if they touch the food. It is not very common to hear of persons suffering from food poisoning because of chemicals. Metals have been thought to be the cause in some cases. Antimony, Poisoning by Plants and Animals arsenic, cadmium, lead, and zinc in foods have been blamed for food poisoningmainly from foods being Some plants and animals may be sources of food prepared, cooked, or stored in containers made of these poisoning. There are poisonous plants in the West. If substances. One summer a family of four became vio- you like to be out of doors and live for a while off the lently ill after enjoying barbecued steak, baked potatoes, wilderness land, you must be sure of your identification and saladall fresh and prepared sanitarily. After before using a plant for food. Some wild plants must Extension Circular 729 August 1965 Cooperative Extension Service Oregon State University Corvallis be carefully processed (such as by leaching) before Warmth, moisture, and time encourage staph they are edible. There are poisonous varieties of mush- growth. In this example we can see how conditions rooms which are easily mistaken for edible kinds. To were right for the growth of staph (a quick way of prevent mushroom poisoning, avoid all mushrooms un- saying staphylococcus) bacteria. First of all, staph are less you are an expert. Rhubarb greens have been re- almost everywhereon the skin, in a person's breath, ported as responsible for oxalic acid poisoning. Ocean and suspended on droplets of moisture or dust particles. mussels and clams during certain seasons of the year Skin infections are ready sources of the staph bacteria, contain a poisonous alkaloid, apparently from plankton and it is for this reason that persons with skin infec- consumed by the shellfish. tions should not handle food. It is hard to keep the organisms out of foods. Poisoning by Microorganisms and Their Products Since we know staph are almost unavoidable, it be- comes extremely important that conditions are kept so The third way food poisoning happens to humans is that the staphylococcus cannot grow to produce the en- as a result of microorganisms and their products. Bac- terotoxin. It is the toxin that is poisonous to humans. teria, molds, and yeasts are microorganisms. Neither molds nor yeasts have been known to cause food poi- Staphylococcus food poisoning is encouraged by soning. Certain types of bacteria have caused food poi- warm foods or foods permitted to stand for long peri- soning. One goes by the name of Clostridium botulinum ods of time at room temperature in the summer months. and another goes by the name Staphylococcus aureus. To let foods stand this way is to invite food poisoning. The staph microorganisms just "love" these conditions Staph toxinA cause of food poisoning of warmth and moisture, and they grow and flourish to form toxin along the way. Staphylococcus food poisoning is the most com- monly occurring true food poisoning. When the Staphy- Proper refrigeration prevents the formation of the lococcus grows in food, it produces an enterotoxin. It toxin of the staph by preventing growth of the micro- is this toxin which is poisonous to a person when he organisms. Staphylococci can be killed by heating to eats toxin-containing food. The toxin causes inflamma- boiling. But, if toxins have developed before heating, tion of the lining of the stomach and intestines. If you these toxins may not be destroyed by boiling. This is have experienced food poisoning or have heard about one of the main reasons for careful refrigeration of all someone who has, you know how awful it feels. The perishable food. Do not give the toxin a chance to symptoms include nausea, vomiting, retching, abdom- develop. inal cramping of various severity, and diarrhea. Also, there may be headache, muscular cramping, sweating, Foods encouraging to staph growth. Foods most chills, prostration, weak pulse, shock, and shallow res- involved in causing outbreaks of staphylococcus food piration. Although a person suffering this way feels he poisoning are: custard and cream-filled bakery goods, is surely going to die, death from this kind of food ham, tongue, and poultry. Other foods incriminated poisoning is rare. The duration is briefusually a day include: other meats and meat products, fish and fish or two. Recovery is complete (although you probably products, milk and milk products, cream sauces, salads, will not believe it while you are in the first miserable puddings, custards, pies, and salad dressings. If left- stages of the food poisoning). over turkey or other fowl, along with gravy and dress- ing, is kept out of a crowded refrigerator, it may cause A true story about staph food poisoning. A pic- poisoning. nic, a tour, or an outdoor luncheon for large numbers of people are examples of occasions which precede an Staph do not grow well in high acid foods. However, outbreak of food poisoning. One example is a livestock acid foods may be reduced in acidity by adding ingredi- tour in one of the western states. Out of about 350 ents, such as eggs or cream, and then become dangerous. people nearly 300 got sicksome within a couple of Time can be a factor. Foods warmed for extended hours; some started home but got sick along the way. periods of time, such as on steamtables in cafeterias and About half the stricken people needed hospital care. restaurants and food-vending machines,favorthe They all recovered completely. growth and toxin-production by staphylococci. The cause was traced to the potato salad served at the noon meal at a ranch 25 miles out of town. The We can summarize with these simple rules: meal was served out of doors on a warm day from 11 am, to 1:30 p.m. Many people prepared the food, with Cultivate clean habits.Cleanliness in handling a few responsible for providing the potato salad. There foods is vital. was such a large amount required to serve 350 persons that it would not fit in the household refrigeration space Keep foods cold. When foods are cooked to high available. Also, the salad was brought early enough so temperatures, keep them hot. To store for a that the tables could be arranged and ready for serving while, refrigerate hot foods promptly. Do not at 11 a.m. allow a lingering cooling period. Approximate High-Quality Life of Some Perishable Foods Held in a Home Refrigerator One or two days Fruit: Meats, poultry, fish: Vegetables: Berries Ground meats Sweet corn Ripe tomatoes Variety meats (liver, kidney, Asparagus brains) Broccoli Poultry, cut-up and whole Lima beans, shelled Fish Brussels sprouts Leftover cooked meats and meat Spinach and other green, leafy veg- dishes etables Lettuce Green onions Green peas Three to five days Dairy products: Fruit: Meats: Vegetables: Milk and cream Cherries Fresh meat cuts Cabbage Cottage cheese Grapes Hearts Cauliflower Peaches Cold cuts Lima beans, unshelled Apricots Corned beef Snap beans Ham slice Celery Ham, half Carrots, tops removed One week Fruit: Poultry products: Meats: Apples, eating-ripe Shell eggs Bacon, sliced Oranges Grapefruit Lemons Two weeks Dairy products: Meats: Soft cheese (other than cottage cheese) Cured ham, whole Butter Dried beef, sliced Clostridum toxinA cause of food poisoning ods.