Food Preservatives
Introduction
- Food preservatives are natural or synthetic chemicals that are added to foods or pharmaceuticals to retard spoilage, whether from microbial growth, or undesirable chemical changes.
- Some methods of food preservation involve the use of salt, sugar or
vinegar, which is sometimes considered to be foods rather than additives. - Some people believe preservatives are harmful.
- Food preservatives have been around since centuries ago, as in pickled onions, salted meat and fish, sweetened fruit and spiced foods.
- As people move away from the countryside and demand for food increased many people rely on processed items as part of their daily sustenance.
- Food preservatives help maintain the freshness and shelf life of such food products because, without them, they would spoil quickly due to exposure to air, moisture, bacteria, or mold.
- Either natural or synthetic substances may be added to avoid or delay these problems.
History of preservatives
- Preservatives have been used since prehistoric times.
- Smoked meat, for example, has phenols and other chemicals that retard spoilage.
- The preservation of foods has evolved greatly over the centuries and has been instrumental in increasing food security.
- The use of preservatives other than traditional oils, salts, etc. in food began in the late 19th century but was not widespread until the 20th century.
Importance of preservatives
- Food preservatives are essential for many reasons. They are used to:
- o Maintain consistency and texture of foods
o Improve or retain nutritional properties
o Delay spoilage
o Enhance flavors, textures, and color
- o Maintain consistency and texture of foods
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Maintaining consistency and texture of foods
- It helps to sustain smoothness or prevent the food from separating, caking or clumping.
- Preservatives slow product spoilage caused by mold, air, bacteria, fungi or yeast.
- In addition to maintaining the quality of the food, they help control contamination that can cause foodborne illness, including life-threatening botulism.
- One group of preservatives — antioxidants – prevents fats and oils and the foods containing them from becoming rancid or developing an off-flavor.
- They also prevent cut fresh fruits such as apples from turning brown when exposed to air.
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Improve or retaining nutritional properties
- Enrichment replaces nutrients lost in processing — this occurs with grains, as some vitamins and minerals are lost in the milling
process. - Fortification adds a nutrient that wasn’t there before and may be lacking in many people’s diets.
- Iodized salt is an example.
- This has proven useful in preventing goiter, a thyroid disease caused by a deficiency in iodine.
- Enrichment replaces nutrients lost in processing — this occurs with grains, as some vitamins and minerals are lost in the milling
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Delaying spoilage
- Preservation usually involves preventing the growth of bacteria, fungi (such as yeasts), and other microorganisms, as well as retarding the oxidation of fats which cause rancidity.
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Enhance flavors, textures, and color
- Spices, natural and artificial flavors, and sweeteners are added to enhance the taste of food.
- Food colors maintain or improve appearance.
- Emulsifiers, stabilizers, and thickeners give foods the texture and consistency consumers expect.
- Leavening agents allow baked goods to rise during baking.
- Some preservatives help control the acidity and alkalinity of foods, while other ingredients help maintain the taste and appeal of foods with reduced fat content.
Classification:
- Natural or class I preservatives:
In this category of natural food preservatives comes the salt, sugar, alcohol, vinegar, spices, syrup, edible oil and honey.
- Chemical or Class II preservatives:
In this category, chemical preservatives are included like sorbates, nitrites, benzoates, sulfites, nitrates of sodium or potassium, glycerides, glutamates and so on.