Food Chemistry and Fish in Nutrition ( 2+1)

12.1.3.Antimicrobial agents or Preservatives

Antimicrobial agents or Preservatives

Antimicrobial agents or preservatives prevent or inhibit spoilage of food due to fungi, bacteria and other microorganism.

Microbes will grow quickly when they are in the right conditions; warm, moist, correct pH and a supply of food to grow on. Preservation tries to alter the conditions to slow or stop the microbe growth. When this is not possible, or convenient, preservatives may be added to stop the food from going 'off'. Different microbes are sensitive to different types of preservatives and so a wide range of preservatives are in use today.

List of some important preservatives

i) Sorbic acid and its salts (E200-203): Sorbic acid and its salts are naturally occurring substances and they are among the most important food preservatives. Sorbic acid gives no taste or flavour to products and it is effective over a wide range of foods and beverages. Sorbic acid is used in beverages, dairy products, fish and seafood, fat-based products, fruit and vegetable products, baked goods and confectionery products.

ii) Benzoic acid and its salts (E210-E213): A widely used preservative. It is only used in acidic situations which include non-alcoholic beverages, products prone to spoilage by bacteria and fruit-based products.

iii) Sulfur dioxide and sulfites (E220-E228): These preservatives are multifunctional food ingredients which act as preservatives, antioxidants and colour stabilizers. They have a much more pronounced antibacterial effect than other preservatives and are therefore used when control of bacterial growth is essential. Sulfur dioxide is used in a wide range of products including packet soup, dried bananas and apricots, tinned crabmeat, sausage meat, beer, wine, quick frozen chips and jams

iv) Potassium nitrite and sodium nitrite (E249 and E250): They act as preservatives, stabilizers and flavours. Potassium and sodium nitrite are particularly important in the preservation of cured meat products.

v) Propionic acid and its salts (E280-E283): The propionates are also naturally occurring preservatives. They work better in the more alkaline conditions of bakery products and may be used, for example, to delay the green mould growth on bread