What are the appearances when the food spoils?

During storage and distribution, foods are exposed to a wide range of environmental conditions. Food spoilage occurs when products develop undesirable odors, flavors and appearances due to microbial growth.

Quite often, the evidence of microbial growth is easily visible as in the case of slime formation, cotton-like network of mold growth, iridescence greening in cold cuts and in cooked sausage, and even discrete large colonies of bacteria. Food spoilage also produces undesirable aromas and color defects.  

In liquid such as juice, microbial spoilage is often manifest by the development a cloudy appearance or curd formation.

Spoiled food, such as moldy bread, soured milk or bad fish may not cause any harm or illness if consumed.

On the other hand, if food is contaminated with pathogenic bacteria then a potentially dangerous food poisoning may occur.
What are the appearances when the food spoils?

Food Additives as Preservatives and Appearance Additives

Food Additives as Preservatives and Appearance Additives
Preservatives are added to food substance to slow spoilage and deterioration. Some sources estimate that there are about 100 common preservatives being used by the food industry.

Preservatives are specific to the food being preserved; antioxidants are used in fatty products, for example, while breads often have “mold inhibitors.”

Other common multipurpose preservatives are familiar ingredients such as salt, sugar and vinegar. All of these extend the shelf life of food products and reduce the risk of food related disease.

Some preservation techniques , such as irradiated food, aseptic processing and microwave pasteurization, reduce the need for conventional food additives used to reduce spoilage, but their safety is sometimes debated.

Appearance additives include texturizers, coloring agents and flavorings. These additives enhance the look, mouthfeel or taste of foods without changing other characteristics.

Texturizers are put into food products to maintain a desired texture, and sodium nitrate is used to develop and stabilize the pink color in meats.

Coloring agents are used to increase attractiveness of food to consumers; foods that are frequently colored include candy, soft drinks and diary products such as butter, cheese, and cream.

Flavoring additives are the most common type of additive approved for human consumption. If the roughly 3,000 additives approved, about 2,000 are flavorings used to replace the flavors lost during processing.

Hence, this category of additives used mainly to appeal to user tastes and to enhance purchasing of the target food product.
Food Additives as Preservatives and Appearance Additives