spongy.2 2. It makes the product digestible.
3 3. It makes it soft.
4 4. It makes the product tastier and appetizing.
The leavening agents used as additives are mainly of two types.
a. Biological agent: Biological leavening agents are harmless microorganism like yeast Saccharomyces cerevisiae. The yeast cell added ferments the sugar and produces carbon dioxide and ethanol. The yeast added may be active dry yeast or compressed yeast.
b. Chemical agents: Three types of chemical leavening agents are used. They are baking soda, baking powder, and ammonium bicarbonate. Baking soda contains sodium bicarbonate (NaHCO3) that releases carbon di oxide when heated. Baking soda is always used with acid like buttermilk, vinegar, lemon juice, molasses, honey, vinegar, buttermilk, cocoa fruits, fruit juices, and cream of tartar. Baking powder contains baking soda, dry acids, and starch. Baking powder may be either single acting powder or double acting powder. In single acting baking powder carbon dioxide is released as soon as it is added in the liquid. Double acting baking powder releases carbon dioxide in two stage: first is when it is mixed in cold liquid and second is during baking. Ammonium bicarbonate is another leavening agent that produces carbon dioxide when it decomposes. They are used in the products which are finally dry and porous so that all the ammonia liberated during heating gets released otherwise it will affect the taste.
2.3.6.8 Firming Agent
These are the additives that give firming action to food. Fruits and vegetables contain pectin that is relatively insoluble and form firm gel around the tissues of fruit. Firming agents are additives that help to precipitate residual pectin. It strengthens the supporting tissue and prevent its collapse during processing. Calcium salts are used as firming agent. It forms calcium pectate gel that protects the tissues against softening during processing. Some of the other examples of firming agents include aluminium sulfate, ammonium aluminium sulfate, calcium chloride, calcium sulfate, and sodium/potassium aluminium sulfate.
2.3.6.9 Glazing Agent
Food glazing agents are additives also known as polishing agent. When they are applied on food material, it gives a protective and shiny coating on fruits, bakery and confectionary items. These additives are prepared from either natural or synthetic sources. Common glazing agents are beeswax, lac, mineral oil, etc.
2.3.6.10 Humectant
These are hygroscopic substances that promote moisture retention. It prevents the food from drying out. Polyols including propylene glycol, glycerol, sorbitol, and mannitol are some examples of humectants. They contain several hydroxyl groups that makes them hydrophilic that enables them to bind with water. They are also known as moisture retention agent or wetting agent. Examples of products where humectants are used include shredded coconut, cookies, glazed and dried fruit, and cake.
2.3.6.11 Sequestering Agent
Sequestering agents are also known as chelating agent. They protect food products from chemical, oxidative, and enzymatic reactions that promote deterioration of food through chelation during processing and storage. They form chelate with polyvalent metal ions like copper, iron, and nickel. Even at very low concentration of these metal ions as low as 0.05 ppm, they can cause rancidity, discoloration, spoilage in texture, odor, and flavor. Copper can affect ascorbic acid, folic acid, vitamin E, and thiamine. Vitamin A will be destroyed by both copper and iron. Fats and oils are also oxidized in presence of metal ions that act as catalyst. Examples of chelating agents are EDTA, polyphosphate, citric acid, and tartaric acid.
2.3.6.12 Gelling Agent
These are the food additives that are used with the purpose to thicken and stabilise various foods like jelly, desert, and candies. The change the texture of a food by forming gel. Typical gelling agents are natural gum, starches, pectin, agar, and gelatin. The provide the food a texture by the formation of gel. Some stabilizers and thickening agent are also gelling agent. These agents are polysaccharide or protein as per their nature.
2.3.6.13 Propellants
Propellants are the food additives that are used in foods like carbonated drinks to expel it out of their container. A propellant creates more pressure to liquid food so that it will come out from its container. It is also used in whipped creams. Common propellant includes carbon dioxide, nitrogen, nitrous oxide, propane, and butane. They are also used to reduce the amount of oxygen in contact with the food in the container. Nitrous oxide and carbon dioxide are better propellants as they dissolve in the liquid food and expand during its release from its container.
2.3.6.14 Foaming Agent
These additives are also known as aerating agent. It facilitates the formation of foam and helps in the formation of uniform dispersion of gaseous phase over liquid or solid food. They are used in toppings, cake mixes, whipped creams, beverages, and soft drinks. Examples are propylene glycol ester of fatty acid, glycyrrhizin, alginic acid, and polysorbate.
2.3.6.15 Seasoning
They are the additives from plant origin. They are added in food and drinks to improve the taste and aromatic fragrance. They are obtained from different parts of the plant like root, leaves, flower, bud, fruits, seeds, and whole plants. A list of some common spices along with their bioactive compounds are presented in Table 2.6. They also add phytonutrients, essential oil, antioxidants, vitamin, and minerals to the food where it is applied [20].
Table 2.6 List of some common spices and their bioactive compounds [21].
| Spice | Bioactive compound | Benefits |
|---|---|---|
| Black pepper | Piperine, piperidines, and pyrrolidines | When applied in meat products, it decreases lipid peroxidation. |
| Paprika | Capsaicin | It reduces inflammation and stimulate digestion. |
| Turmeric | Curcumin, curcuminoid | It reduces join pain and stomach pain. |
| Ginger | Gingerol, shogaols, paradols | It has anti-blood clotting activity, stimulates digestion, and reduces bacterial and fungal infection. |
| Cardamom | Eucalyptol, limonene, cineole, and α-terpinyl acetates | It has anti-microbial properties and can improve cardiovascular health. |
| Vanilla | Vanillin | It has antioxidant and antimicrobial property. |
