Flavoring Agent
4. Coloring Agent
5. Texturizing Agent
6. Miscellaneous Additives [7]
Figure 2.1 Types of food additives.
2.3.1 Preservatives
The food additives under this category are used for the preservation of the food. Food may be easily spoiled by the microorganism or by chemical or enzymatic reaction. The addition of preservative may inhibit the growth of spoilage microorganism or they may inhibit chemical and enzymatic reactions. The food preservatives may be of following three types.
i. Antimicrobials: These additives are added for their ability to inhibit the growth of microorganism. Common additives include benzoates, sorbate, acetic acid, nitrate and nitrites, sulfur dioxide, antibiotics, and phosphates. The overall mode of action of these antimicrobial compounds includes reduced water availability and increased acidity. Natural antimicrobials have the dual benefit that they can inhibit the microorganism as well as make the food safe for eat. They may be derived from microorganism or animal or plant source. Some examples of natural alternative of food preservative include Natamycin, which is an antibiotic selectively that inhibits mold but the growth of bacteria required for ripening of cheese. Nisin and Pediocin are bacteriocin produced by microorganism that is effective on other microorganism. Lysozyme, enzyme lactoperoxidase, and lactoferrin are examples of antimicrobial derived from animal source. Antimicrobial extracted from plant source includes essential oils.
ii. Antioxidants: Antioxidants are additives that are added in to the food to prevent the oxidation reaction. In food material, two types of oxidation reaction may occur: a. enzymatic oxidation of fruits and vegetables; and b. oxidation and rancidity of fats and oils. Antioxidants used in the food material are of following five types:a. radical scavenger or chain breaking antioxidant that is primary antioxidant and it binds with the free radical formed during oxidation reaction, thus preventing the chain reaction;b. chelator binds with metal and prevents them from radical formation;c. quencher that inactivate high energy oxidant;d. oxygen scavenger that removes oxygen from the system;e. antioxidant regenerator that regenerates the antioxidants.Polyphenols are natural antioxidants like flavonoids, tannins, lignans, and coumarins. Natural antioxidant also includes Ferulic acid, Catechin, Ascorbic acid, Tocopherol, Carotenoids like Lycopene, and β-carotene. They are generally used as plant extracts. Synthetic antioxidants include Butylated Hydoxy Anisole (BHA), Butylated Hydroxy Toluene (BHT), tbutylhydroquinone (TBHQ), gallate, and stannous chloride [8–10].In contrast to synthetic antioxidant scientists are finding alternative source of antioxidant in nature. They found that algae contain natural antioxidative compounds that affect various pathogenic organisms with low-cost isolation process. The main antioxidant includes vitamin C and E, carotenoids, polyphenols, and chlorophyll. The red and brown algae contain high levels of folic acid and folate. Two species of cyanobacteria Spirulina platensis and Spirulina maxima are considered as supplements. They have the capacity of lowering lipid content in human body, antioxidant and anti-inflammatory effect. They have high nutritional value. They are considered as important food during long term space mission by NASA. Other important algae include Chlorella vulgaris, Phaeodactylum tricornutum, Gayralia oxysperma, Chaetomorpha antennina, Sargassum vulgare, and Chondrus crispus. They have high antioxidant capacity and have a potential to act as a source of natural antioxidant.
iii. Anti-browning agent: The development of brown or gray or black color in food product is due to browning reaction that may be of two types.a. Enzymatic browning that makes the formation of quinones by the oxidation of polyphenols in presence of polyphenol oxidase. It can be prevented by blanching, acidification, and addition of sulfites.b. Non-enzymatic browning occurs due to the reaction between reducing sugar and free amino acids resulting melanoidin pigment. It can be prevented by avoiding excessive heat, controlling moisture content, and application of sulfites. Sulfites are used in the form of sodium (or potassium) sulfite, bisulfite, or metabisulfite. Other anti-browning agent includes ascorbic acid, cysteine, and 4-Hexylresorcinol.
2.3.2 Nutritional Additives
Nutritional additives mean addition of pure compounds like vitamin, mineral, amino acid, and fatty acid to maintain or improve the nutritional quality of food. It is also added for other purposes, like vitamin C and E are added as antioxidant, and carotenoids are added to improve color.
Nutritional additives include fortification of salt with iodine, enrichment of cereal and dairy products with vitamin A, B, and D, enrichment of fruit beverages with vitamin C, essential fatty acid, mineral, and fiber [11].
2.3.3 Flavoring Agent
Flavoring agent includes flavorings and flavor enhancers. Flavorings added in the food produce flavor in the food, while flavor enhancer intensifies the existing flavor. Food flavoring may be of three types.
a. Natural flavoring: These are single or mixed substances obtained from vegetable and animal source. This type of flavoring includes spice oleoresin and essential oils from citrus oils.
b. Nature identical flavoring: These are the chemical substances but the identical substances are present in nature.
c. Artificial flavoring: These types of compounds are completely synthetic and they are not identified in natural products.
Natural flavor includes spices, herbs, essence, and essential oil. The synthetic flavor includes esters, aldehydes, ketones, alcohols, and ethers. Monosodium glutamate is an example of widely used flavor enhancer [12, 13].
2.3.4 Coloring Agent
Coloring agents are added into the food to make it attractive and to influence the flavor. The other reasons for the addition of food color are as follows:
a. Color may be lost during processing and storage, so to compensate it, food color is used.
b. Food material containing natural color may show variation of color food color is added to correct that variation.
c. Food color is added to improve the color imparted by the natural color.
d. Food color is used for the food items having no color.
As per FDA regulation, the colors added may be with or without certification. The certified colors are man-made color. They are more effective than the natural color. They do not introduce any off flavor in the food. The natural colors are exempted from certification but they are more expensive and can produce off flavor. Color additives used may be of three types.
a. Pure pigment or straight color.
b. Colors obtained by mixing the straight colors with other substances.
c. Mixtures produced by mixing two or more pure colors.
Natural food color includes annatto, betanin, saffron, lycopene, and anthocyanin. The certified food color includes Erythrosine, Tartrazine, Sunset Yellow, and Brillant Blue
