User:AylinM27/Food spoilage

Food Spoilage

Food spoilage is the process by which a food product becomes unsuitable for consumption. The cause of food spoilage varies depending on environmental conditions, microbial activities, or the food product’s endogenous mechanisms. Additionally, the most common cause for food spoilage is due to improper compartmentalization, where the food product is inadequately stored, exposing it to external factors compromising its quality and safety. Food spoilage can be detected in several ways: exhibiting an abnormal exterior appearance, such as discoloration, or the food product may induce an unappealing smell, or an unpleasant taste. The primary culprits of food spoilage are fungi, bacteria, and moulds.  

Common foods associated with food spoilage include:

1. Meat Products
2. Fruit & Vegetable Products
3. Diary Products

Signs of Food Spoilage

Signs for detecting food spoilage include discoloration, unpleasant odors, change in texture, present colony formations, or undesirable taste. Although not all food products display spoilage through physical characteristics, awareness of these signs is crucial for consumption safety. Thus, practicing proper food handling is necessary.

Below I have listed examples of food spoilage in common products:

1. Spoiled milk can be detected when the product presents itself as chunky, curdled, thick, and yellowish in appearance.
2. Spoiled meat displays a discolored appearance and may present a slimy, sticky, or tacky residue.
3. Spoilage in vegetables may present browning or darkening spots, mold or fungus, and a rotten smell.

Consequences of Food Spoilage

Example of Spoiled Moldy Cheese

Food spoilage poses significant consequences within the food industry due to substantial losses in profit and potential health implications for consumers. Approximately 25% of available food perishes due to food spoilage, which can occur at any stage of the harvesting or post-harvesting process. Additionally, if consumption is undertaken, it may cause harm to the human body and start an outbreak of food-borne illnesses. The biggest threat caused by spoiled food is the consumption of mycotoxins, a toxic compound produced by fungi.

Mycotoxins

Mycotoxins are produced by the secondary metabolism of fungi or mold that develops under favorable conditions. Moreover, mycotoxins can destroy and devastate harvest and may prolong post-harvest if environmental conditions allow them to reproduce.  

Foods that may potentially be contaminated with mycotoxins:

1. Staple Cereals
2. Peanuts
3. Dried Fruits
4. Spices

The Impact of Mycotoxins on Health

The effects of consuming Mycotoxins are detrimental; these include acute diseases called mycotoxicosis and the potential risk of food-borne illness outbreaks. Throughout history, several reports of outbreaks have occurred due to mycotoxins. Additionally, researchers have discovered the correlation of Aflatoxins, a type of mycotoxin, and its associated risk of liver cancer, liver disease, and fatal kidney disease.

In England in 1960, there was an outbreak of Turkey X disease caused by aflatoxins. The outbreak involved the death of thousands of turkeys, and it was later discovered that there were present pathogenic changes in the liver of the turkey.

In Kenya in 2004, 317 individuals consumed contaminated maize with present aflatoxins, which was labeled the largest outbreak of aflatoxicosis in history, leading to the death of 125 individuals.

Thus, the consumption of mycotoxins can produce toxic effects on animals and humans. Some effects involve carcinogenicity, teratogenicity, immune toxicity, neurotoxicity, and other consequences.

Bacteria

Bacteria are one of the microorganisms responsible for food spoilage in meats, poultry, fish, milk, and other food products. Acid and other waste products are generated when bacteria break down the food product. While the bacteria may or may not be harmful, the waste products it produces could potentially implicate health risks if consumed. Additionally, the bacteria responsible for food spoilage varies; it could be gram-negative rods, gram-positive spore formers, lactic acid bacteria, or others not listed. However, the most common bacteria associated with food spoilage are Bacillus cereus, Clostridium algidicarnis, and Pseudomonas fluoresces.  

For example, Bacillus can contaminate egg products because of their unique spore-forming properties. The biggest safety concern about Bacillus is their ability to produce enterotoxins in eggs. But the bacteria is not limited to eggs, but can spoil all types of food. When stored or subjected to unruly conditions, the organisms will begin to breed apace, releasing harmful toxins that can cause severe illness, even when cooked safely.

Another example is Clostridium algidicarnis, the bacteria responsible for the spoilage of refrigerated vacuum-packed meats. As a result of contamination, the product loses its color and texture and generates a strong foul odor.

Moreover, Clostridium butyricum is the bacteria responsible for the spoilage found within low-acid canned foods. Furthermore, it's also responsible for spoiling and producing gas in hard cheese.

Last but not least, Pseudomonas fluorescens is a bacterium that causes food spoilage of normal and refrigerated goods because of its enzyme and pigment production.

Fungi: Yeast & Molds

Fungi contribute to food spoilage, causing food products to appear undesirable. Spoilage caused by fungi can make the food product unpalatable or unsafe for consumption because it disintegrates the product, acidifies it, and renders its nutrients. Due to the present fungi, the food commodity shows fuzzes, powders, slimes and discoloration of black or brown. Most importantly, the growth of fungi on food product is based on eight principal factors: water activity, ph—levels, temperature, gas tension, consistency, nutrient status, preservatives, and solute effects.

Yeast

Yeast is another contributor to food spoilage. It is a type of fungi that grows vegetatively via single cells that either bud or divide by fission. This allows yeast to multiply in liquid environments, favoring the dissemination of single-celled microorganisms. However, it cannot expand or thrive on solid surfaces. It is important to understand that there are two types of yeast spoilage; the first one consists of visible white, cream, or pink patches on the surface of bakery commodities, and the second consists of the fermentative spoilage.

Some of the most common yeasts responsible for food spoilage are Zygosaccharomyces and Candida. The presence of yeast spoilage mainly occurs in food products that present the following conditions: high sugars, organic acids, carbon sources, and a low pH level of 5.5 or lower.

Zygosaccharomyces is a genus bacteria responsible for the spoilage of high-sugar and high-salt products. These products include fruit juices, dried fruit, honey, jams, soft candy, and other varieties. The growth of this yeast is slow, but its most dangerous aspect is gas buildup in the packaging.

Molds

Mold, a type of fungus, is another contributor to food spoilage, but the two terms, mold, and fungus, are not reciprocals of each other: they have their defining features and perform their tasks. To prevent mold from expanding, controlling environmental conditions can inhibit the production of spores. Some potential ways to control these environmental conditions are domineering oxygen levels, temperature levels, and employing an alternative approach to limit the production of spores. However, the most popular molds are Penicillium and Aspergillus.  

Penicillium expansum is a primary spoilage fungus and a leading producer of the mycotoxin patulin, primarily found in fruit juices. This occurs because the processing fruits are contaminated with rotting areas, leading to spoilage, especially, in apple and pear juices. On the other hand, Penicillium digitatum causes discoloration and destructive brown rots on oranges and other Citrus fruits. Above all, nearly every food is contaminated with Penicillium spores, which are made visible when a single colony grows. Consequently, the consumption of Penicillium can cause rashes, gastrointestinal discomfort, and hypersensitivity.

Aspergillus is another spoilage contributor; it can produce mycotoxins, specifically aflatoxins, secondary metabolites. Moreover, its production of Aflatoxin B1 is recognized as the most potent liver carcinogen. Additionally, its production of Ochratoxin A can damage kidney function. The consequences of encountering Aspergillus may be harmless or mild, but it can lead to severe infection for individuals who are immunocompromised or have an underlying lung disease like asthma. But the most severe consequence is aspergillosis, which is an invasive aspergillosis that causes the infection to spread to various parts of the human body like the blood vessels and lungs.

Prevention

Several methods of prevention can be used to delay, reduce, or totally prevent food spoilage. Some examples include a food rotation system, food preservatives, and proper food compartmentalization. Below is a list of ways to prevent food spoilage to protect the food product’s quality and your health:

1. The Food Rotation System uses the first-in-first-out method (FIFO), which ensures that the first item bought is the first item consumed.
2. Preservatives are another measure that prolongs the life span of food products so they can be harvested, processed, sold, and kept in the consumer's home for a reasonable time.  
3. Drying, an age-old technique, is another measure for food preservation. It is the process of dehydrating food, preventing mold and fungus growth. While there is a potential chance of fungi developing on dried food products, the chance is quite low.
4. Refrigeration can increase the shelf-life of particular food and beverages, though it does not indefinitely expand it with most items. Freezing can preserve food even longer, but it also has its limitations.  
5. Canning can preserve food for an exceptionally extended period, whether at home or commercially. Canned food is vacuum-packed to remove oxygen from the can, which is the primary motivator for bacterial growth in aerobic spoilage.
6. Lactic acid fermentation also preserves food and prevents spoilage.
7. Practice the four-step system: Clean, Separate, Cook, and Chill.
8. Finally, food commodities like meat, poultry, milk and cream should be kept out of the danger zone, which is anything between 4° and 60 °C (40°F and 140 °F). Within this danger zone would be dangerous because pathogenic toxins may be emitted, resulting in severe illnesses.

Disclaimer

This page is an edited addition to the original Food Spoilage page on Wikipedia.