Food Preservatives:
Antimicrobial preservatives combined with good manufacturing practice,provide a useful role to ensure safe food products. The purpose is generally to avoid spoilage during the transportation time and extend the shelf-life of foods, thus reducing waste, diposal and costs. Food preservatives are divided into two categories such as organic acid and salts.

Organic Acids

• Commonly used for flavour and tartness to stabilize colour, reduce turbidity, enhance gelling and as anti-microbial agent.
• Acetic acid is effective against yeast, bacteria and molds. It is used as a pickling agent in condiments, cheese, dairy product analogues, sauces, gravies and meats.
• Lactic acid is the primarily preservative in fermented products as well as being a pH-control agent and flavouring. It used in salad dressings, sauces, soups and desserts.
• Propionic acid and propionate are used against molds, some yeasts and bacteria in flour, bread, whole-meat products and cheese products.
• Citric acid although not used directly as an anti-microbial agent but it has activity against some molds and bacteria.
• Benzoic acid and sodium benzoate are used to control yeasts ans molds which are most effective at pH 2.5-4.0 and least effective at pH above 4.5
• Sodium benzoate is extensively used in beverages, salad dressings, condiments margarine, sauces, gravies and pastry fillings.
• Other organic acid include malic, succinic, tartaric and caprylic acids.

Salts

• Sodium nitrite primarily function as an antimicrobial agent is to inhibit the growth and toxin production Clostridium botulinum in bacon, sausage, and other poultry products.
• Sulphur dioxide and its salts are used as anti-microbial agents and prevent enzymatic and non-enzymatic discolouration in foods.
• The sulfites are primarily used in fruit and vegetable products to control acetic acid producing, fermentation and spoilage yeasts and molds.
• Sorbates (potassium, calcium or sodium salts) are effective inhibitors of fungi. Its effectiveness depends on pH, processing, packaging, storage temperature and length and other ingredients.