Before purchasing any food item, look for dents in cans or openings in the package. Food spoilage will begin to occur faster if a can is dented, or if a package has been opened and exposed to air.
When storing foods at home, place newly purchased foods in the back bringing the older products forward. This is the "FIFO" method, "First In, First Out". To get the best quality out of the foods in your refrigerator, freezer or pantry, always store them at the proper temperature.
Foods in cans, jars, bottles or boxes containing non-refrigerated items should be stored in a cool, dry place between 50° and 70° F.
Refrigerated foods should be stored between 38° and 40º F.
Frozen foods should be frozen in their original packaging, or properly wrapped in freezer paper or freezer weight plastic wrap and stored at 0°.
Wash hands and work surfaces often. Because bacteria are always present on our bodies, use suitable utensils for removing food from cans and jars. For example, don’t use your fingers to get a pickle out of a jar!
Don't cross-contaminate. Don’t use utensils that have touched raw meats, or meats in marinades with cooked meats.
Cook foods to proper temperatures.
Refrigerate cold foods promptly.
Keep cold foods cold (40°F) and hot foods hot (140° F)!
Cold foods that are left out of refrigeration for longer than 2 hours or hot foods left to cool for longer than 2 hours, begin to grow bacteria at increasing numbers.
Keep cold foods cold and refrigerate any leftovers immediately. . Generally speaking, refrigerated foods between 34 to 38 degrees will double their shelf life. The exception to this is lettuce or any other product with a high water content, in which case the colder temperatures can cause damage.
Do not allow cold food to come to room temperature. Food that is left too long in this temperature may smell and look just fine but be dangerous to eat. Under correct conditions, bacteria can double their numbers in as little as 30 minutes. With this large number of microorganisms and their waste products, objectionable changes in odor, taste, and texture will occur in foods. The less time food spends between the temperatures of 40 and 140 degrees the better!
Keep hot foods hot. Once food has been cooked, it should be eaten immediately or kept warm at 140º F. Then store the warm leftovers before they have a chance to cool. For storing warm food, first divide it into smaller containers so it will cool faster once refrigerated. Placing a large warm casserole, meat, or other large warm item into the refrigerator can actually raise the temperature of the refrigerator to above 40 degrees.
Minimize food quality losses by reducing exposure of foods to the air, light, sources of moisture and heat.
Avoid cross-contamination when preparing food. If working with raw meat, poultry or seafood, wash your cutting board with hot water and detergent after each use. Never put cooked food on the same plate that held it when it was raw, unless the plate has been washed with detergent and hot water. Rinsing it with water alone will not kill the bacteria from the raw juices. It’s better to use an acrylic cutting board for raw seafood, meats, and poultry as they are easier to keep clean than a wooden cutting board.
Rinse or wash any food, such as melon, that you will be cutting with a knife. Bacteria can enter food on the knife as it is passed through outer skin of a food.
Food Spoilage Food spoilage is a gradual process occurring because of poor sanitation, enzymatic or chemical reactions, improper temperature controls, microbial growth or physical abuse.
Microbial spoilage is caused by microorganisms and their by-products; non-microbial spoilage can be caused by foreign material in the foodstuff or by enzymes that occur in the foodstuff naturally. Bacteria need about four hours to adapt to a new environment before they begin rapid growth. In handling food, this means we have less than four hours to make a decision to cool the food, heat it, or eat it. If you don't decide, the bacteria will begin to grow rapidly and cause the food to spoil. Bacteria produce the slime, toxins, off colors and odors associated with food spoilage. If we can control bacterial growth, we can control the major cause of food spoilage necessary for microbial spoilage.
Foods are naturally contaminated with microorganisms. To keep the numbers of microorganisms as low as possible, wash fruits and vegetables, especially ones that are getting cut with a knife, such as melons. The bacteria from the outside of the fruit can be brought to the inside. In general, food that is kept at cooler temperatures has a longer shelf life. Refrigerated foods should be kept between 34 to 40 degrees F. Keep a thermometer in your refrigerator and check it often especially during warmer temperatures when the refrigerator may be opened frequently. Like every other living thing, bacteria require food to live. Grease on a blade and food residue on a can opener or on a cutting board is a feast for microorganisms. Any kitchen equipment that comes in contact food with food surfaces should be thoroughly cleaned.
Non-Microbial Food Spoilage Food may spoil as a result of chemical changes within the food itself or by a reaction between the food and the packaging material. Beef, chicken and turkey may be kept frozen up to a year, while sausage and bacon have a much shorter three-month shelf life. This is due, in part, to the high fat content of the sausage and bacon. Fats, like butter and oils, are subject to rancidity. Rancidity is caused by a chemical reaction that breaks down the fatty acids in fat to smaller molecular weight fatty acids and, at the same time, releases certain odoriferous products. So as butter becomes older, it tastes stronger.
Enzymatic Spoilage Enzymes are chemicals produced by all living things. They help speed up or slow down chemical reactions, act as transports for foods, and are a normal constituent of foods. For instance, as a banana matures, the color changes from green to yellow to brown to black. This change is caused by the enzyme ethylene. The ripening, then softening, of other fruits such as apples, peaches and tomatoes is another example of enzymatic action. Enzymes can be inactivated by heat, which is the reason for blanching vegetables; or they can be inactivated by cold temperatures below 40 degrees F, which is the reason for placing fruits and vegetables under refrigeration.
Because bacteria are always present on our bodies, use suitable utensils for removing food from cans and jars. For example, don't use your fingers to get a pickle out of a jar! Wash your hands with soap and water before starting food preparation, before working with new food or new utensils, after finishing food preparation, and before serving food. Avoid cross-contamination when preparing food. If working with raw meat, poultry or seafood, wash your cutting board with hot water and detergent after each use. Never put cooked food on the same plate that held it when it was raw, unless the plate has been washed with detergent and hot water. Rinsing it with water alone will not kill the bacteria from the raw juices. It's better to use an acrylic cutting board for raw seafood, meats, and poultry as they are easier to keep clean than a wooden cutting board. Rinse or wash any food, such as melon, that you will be cutting with a knife. Bacteria can enter food on the knife as it is passed through outer skin of a food. Some leftover foods in the refrigerator will develop an off taste when reheated. This is typical of beef and chicken and is referred to as warmed-over flavor. This is caused by a change in the chemical compounds in the meat responsible for flavor and is not related to bacterial spoilage. Warmed-over flavor may be masked by spices and the food used in barbecued items. Some foods held for long periods of time in the refrigerator after cooking may develop off odors or flavors as a result of the waste products produced by psychrophilic bacteria. Raw foods such as meat, poultry, vegetables and other foods may get slimy or develop an off odor that indicates the food is near the point of spoilage. When the food is cooked or brought to an internal temperature of 165 degrees F, both enzymes and bacteria are destroyed. This food, although edible, may have an off flavor or odor. The off flavor or odor developed is a result of the amount of bacteria on the food before it was cooked. Keep leftover foods covered to prevent contamination and refrigerate them so the temperature of the food is reduced below 40 degrees F as soon as possible. A metal-stemmed thermometer is handy to make quick checks on temperatures of foods. When soups, stews, or meats such as turkey are to be stored in large quantities overnight, they may be cooled by utilizing two steam table pans. Place ice in one pan and the soup, stew or other food in another pan on top of the ice. Once the "flash heat" is removed from the food. It may be placed in four-inch deep covered pans and placed under refrigeration.
How to safely handle refrigerated ready-to-eat foods and avoid listeriosis
Listeria monocyotogenes is a bacterium that can cause a serious infection in humans called listeriosis. Food borne illness caused by L. monocytogenes in pregnant women can result in miscarriage, fetal death, and severe illness or death of a newborn infant. Others at risk for severe illness or death are older adults and those with weakened immune systems. Because L. monocytogenes can grow at refrigerator temperatures and is found in ready-to-eat foods, the Food and Drug Administration (FDA) advices all consumers to reduce their risk of illness by following these procedures:
Store perishable items that are precooked or ready-to-eat at 40 degrees F or lower and consuming as soon as possible
Clean refrigerators regularly
Use a refrigerator thermometer to make sure that the refrigerator stays at 40 degrees F or below.
The FDA is providing the following advice to those at-risk consumers of foods that have a greater likelihood of containing Listeria monocytogenes: (Especially, pregnant women, older adults, or people with weakened immune systems).
Do not eat hot dogs and luncheon meats, unless they are reheated until steaming hot.
Do not eat soft cheese such as Feta, Brie, and Camembert cheeses, blue-veined cheeses, queso blaco, queso fresco, and Panela unless it is labeled as made with pasteurized milk.
Do not eat refrigerated pates or meat spreads. Canned or shelf-stable pates and meat spreads may be eaten.
Do not eat refrigerated smoked seafood, unless it is contained in a cooked dish, such as a casserole. Refrigerated smoked seafood, such as salmon, trout, whitefish, cod, tuna, or mackerel, is most often labeled as "nova-style," "lox," "kippered," "smoked," or "jerky." The fish is found in the refrigerator section or sold at deli counters of grocery stores and delicatessens. Canned or shelf-stable smoked seafood may be eaten.
Do not drink raw (unpasteurized) milk or eat foods that contain unpasteurized milk.