**General Food Additives:**

Substances added during the processing and preparation of food to make it ready for consumption are called additives. Additives are added to foods mainly for three purposes:

Various vitamins, amino acid derivatives, and mineral substances can be added to increase the nutritional value of the food. Characteristics like color, aroma, taste, etc., may partially be lost during processing and storage. To compensate for this loss, certain substances are added to foods. In preventing food spoilage, antimicrobial additives are used to increase resistance to microbial deterioration.

**Classification of Food Additives:**
- Colorants
- Aroma substances
- Preservatives
- Substances affecting the structure and appearance of foods
- Biological value enhancers

**Preservatives:**

Antimicrobial substances (preservatives) are added to foods to eliminate unwanted bacteria, molds, and yeasts—which may be present for various reasons—and to prevent the growth or activity of any pathogenic or non-pathogenic microorganisms.

**Commonly Used Preservatives in the Food Industry:**

**Sulfur Dioxide (SO₂) and Sulfites**

When SO₂ dissolves in water, H₂SO₄ is formed; this acid has very high antimicrobial power. Sulfites prevent yeast, mold, and bacteria. SO₂ is a harmful substance to health. Therefore, it should be used consciously and with well-adjusted doses.

**Nitrites and Nitrates**

They exhibit antimicrobial effects especially in the presence of NaCl (table salt). They are used to control taste, aroma, color, and microbial stability in cured meat products and fish.

**Sorbic Acid**

Sorbic acid and its sodium (Na) and potassium (K) salts are effective against molds and yeasts. Sorbates are used in the food industry in various cheeses, cereal products, wines, jams, jellies and marmalades, sauces, ketchup, ready-made salads and salad dressings, fruit cocktails, margarine, dried fruits, meat and fish products, pickles and brines, and syrups. The most common application area is the cheese industry.

**Benzoic Acid**

In the food industry, the sodium salt of benzoic acid is more commonly used. Benzoic acid and its salts are added as preservatives mainly to pickles, various sauces and ketchup, table olives, margarine, jams, jellies and marmalades, cocoa products, biscuits, wafers and cake creams, non-alcoholic beverages, fruit cocktails, fruit juices, and various syrups.

**Antioxidants**

Many foods contain lipids, and the oxidation of these lipids results in substances that alter flavor and taste. To prevent lipid oxidation, either oxygen needs to be removed or antioxidants need to be added to food products. Antioxidants are divided into two categories: natural and synthetic. The most well-known synthetic antioxidants are BHA, BHT, and propyl gallate.

An additional protective effect is generally provided via antioxidants in vegetable oils, while antioxidants have special importance in the preparation of complex foods subjected to special processes, such as bakery products, instant soups, and cake mixes.

During the production of bakery products, the oxidation of carotenoids can be prevented by adding antioxidants (BHA) or by improving vacuum processing conditions.

Cadmium ions are readily absorbed by plants and are homogeneously distributed throughout all plant tissues.

Below are the levels of Hg, Pb, and Cd in some foods (in mg/l or mg/kg):

**Food Item**

**Hg**

**Pb**

**Cd**

Milk

-

0.02

0.001

Eggs

0.011

0.074

0.024

Meat (Beef)

0.003

0.07

0.016

Green Vegetables

0.004

0.62

0.044

Fruits

0.002

0.17

0.014

Drinking Water

0.0003

0.009

0.001

Wine

0.173

0.003

-

Cereals

0.004

0.041

0.035

Potatoes

0.006

0.075

0.05

Fish (Freshwater)

0.257

0.124

0.02

Fish (Sea)

0.128

-

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