Food Preservatives Overview

Preservatives

• Prevent growth of microorganisms to reduce food spoilage and food poisoning.
• Extend shelf-life of consumer products.
• Natural preservatives include vinegar, salt, and sugar; artificial preservatives include sodium benzoate, sodium nitrite/nitrate, and sulphites.
• Acetic acid (vinegar) disrupts cell membranes in bacteria, yeasts, and molds; used in mayonnaise and pickles (max 3.6%).
• Benzoic acid and benzoate inhibit molds and yeast in beverages and soft drinks (max 0.05-0.1%).
• Natamycin binds sterols in fungal membranes; commonly used in cured cheese.
• Sorbic acid inhibits molds and yeast in cheese, wine, and baked goods (max 0.3%).
• Nitrates and nitrites inhibit bacterial enzymes, primarily Clostridium botulinum, in cured meats.

Antioxidants

• Prevent oxidative rancidity in fat and oil-rich foods.
• Protect vitamins and amino acids from degradation due to air exposure.
• Help maintain appearance of cut fruits, vegetables, and juices by preventing browning.
• Two types: water-soluble and fat-soluble antioxidants.

Colors

• Used to replace lost colors or enhance food attractiveness.
• Simulate perception of naturalness for consumers.
• Natural colorants include caramel (E150), annatto (E160b), and turmeric (E100).
• Synthetic colorants include FD&C Blue No.1 (E133) and FD&C Red No. 40 (E129).

Flavouring Agents and Enhancers

• Flavouring agents impart taste or smell; common examples include spices and herbs.
• Flavour enhancers enhance existing flavours without providing flavour themselves; examples include MSG and natural extracts.
• Monosodium glutamate (MSG) is a common flavour enhancer, enhancing taste in foods.

Anti-caking Agents

• Prevent caking in powdered foods to ensure free flow.
• Common anti-caking agents: sodium bicarbonate and calcium silicate (max 5%).
• Help maintain the texture of instant mixes, powdered drinks, and table salt.

Antifoaming Agents

• Reduce or prevent foaming in foods by lowering surface tension.
• Included in foods and cooking oils to control frothing; an example is dimethyl polysiloxane (max 10ppm).

Emulsifiers

• Stabilize emulsions of oil and water, facilitating mixing of immiscible liquids.
• Two types of emulsions: water-in-oil (e.g., margarine) and oil-in-water (e.g., mayonnaise).
• Emulsifiers have both hydrophilic and lipophilic regions.

Stabilizers

• Maintain uniform dispersion of immiscible substances in food.
• Examples include agar, pectin, and gelatin.

Thickeners

• Increase food viscosity without altering other properties.
• Types include polysaccharides (e.g., cornstarch), vegetable gums (e.g., xanthan gum), and proteins (e.g., egg whites).

Glazing Agents

• Provide a shiny appearance and protective coating on food.
• Common examples are stearic acid (E570) and beeswax (E901).

Sweeteners

• Improve taste and flavor in foods; include both natural (from sugar cane) and artificial (e.g., aspartame) sweeteners.
• High-intensity sweeteners are much sweeter than sugar, while bulk sweeteners have similar sweetness levels to sugar.

Acidulants

• Enhance flavors and act as preservatives; include vinegar and citric acid.

Chelating Agents

• Scavenge metals that catalyze oxidation; examples are EDTA and citric acid.

Curing Agents

• Used in meat preservation to inhibit microorganisms while imparting color and flavor; sodium nitrite is commonly used.

Humectants

• Retain moisture to prevent food from drying out; examples include glycerol and sorbitol.

Firming Agents

• Keep fruits and vegetables crisp; typically aluminium sulphates and calcium salts.

Clarifying Agents

• Remove haze from beverages like beer and fruit juices; examples include bentonite and gelatin.

Advantages of Food Additives

• Extend shelf-life and improve transportability of processed foods.
• Maintain consistent food quality.
• Enhance visual appeal for consumers.

Disadvantages of Food Additives

• Potential health risks or adverse effects on consumers.
• May lead to reduced food quality perceptions.
• Overconsumption can result in health issues.