🍲 Food Additives and Preservatives

This lesson explains core food science and nutrition concepts with practical relevance to food quality, safety, and human health.

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Food Additives and Preservatives

Definition and Classification

A food additive is any substance intentionally added to food to perform a specific technological function such as preservation, coloring, flavoring, or improving texture. Food additives are regulated by national and international bodies to ensure consumer safety.

Classification of Food Additives

1. Preservatives — prevent microbial spoilage and extend shelf life
2. Antioxidants — prevent or delay oxidative deterioration (rancidity)
3. Colors — enhance or restore visual appearance
4. Flavoring agents — impart or enhance taste and aroma
5. Emulsifiers and stabilizers — maintain uniform dispersion of immiscible phases
6. Thickening agents — increase viscosity (starch, pectin, guar gum)
7. Sweeteners — provide sweetness (nutritive and non-nutritive)
8. Acidity regulators — control pH of food products

GRAS (Generally Recognized As Safe)

The GRAS concept, established by the US FDA, refers to substances that are generally recognized by qualified experts as safe under intended conditions of use. Common GRAS substances include salt, sugar, vinegar, baking soda, and spices. In India, FSSAI regulates the permissible list of food additives and their maximum limits.

Permitted Preservatives

Chemical Preservatives

• Benzoic acid and sodium benzoate — effective against yeasts and molds at acidic pH; used in fruit juices, pickles, and carbonated beverages (max 750 ppm)
• Sorbic acid and potassium sorbate — effective against molds and yeasts; used in cheese, bakery products, and wine
• Sulfur dioxide and sulfites — used in dried fruits, wine, and fruit pulps; act as antimicrobial and antioxidant; may cause allergic reactions in sensitive individuals
• Nisin — a natural bacteriocin produced by Lactococcus lactis; effective against Gram-positive bacteria; used in processed cheese and canned foods

Antioxidants

• BHA (Butylated Hydroxyanisole) and BHT (Butylated Hydroxytoluene) — synthetic antioxidants used in fats, oils, and snack foods
• Ascorbic acid (Vitamin C) — natural antioxidant; also acts as oxygen scavenger
• Tocopherols (Vitamin E) — natural antioxidant in vegetable oils
• TBHQ (Tertiary Butylhydroquinone) — highly effective in vegetable oils and frying fats

Colors and Flavors

Permitted food colors in India are classified as natural (e.g., turmeric, annatto, caramel, beetroot red) and synthetic (e.g., tartrazine, sunset yellow, erythrosine). FSSAI permits only a limited list of synthetic colors with prescribed maximum limits.

Flavoring agents include natural flavors (vanilla, essential oils, spice extracts), nature-identical flavors (chemically synthesized to match natural compounds), and artificial flavors. All flavoring substances used in food must comply with FSSAI regulations and Codex Alimentarius guidelines.

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Summary Cheat Sheet

Topic	Key takeaway
Main focus	Food additives and preservatives — GRAS, permitted preservatives, antioxidants, colors, and flavors.
Section context	Revise this lesson with the rest of Principles of Food Science and Nutrition for stronger conceptual continuity.