Food Chemistry. Группа авторов

turns to pink from yellow at low pH and chlorophyll turns to brown from green. This makes natural origin colorants more expensive. For example, natural red and yellow colorants may cost 100 times more than synthetic products with the same effect. Natural coloring matters are synthesized by plant and animal organisms or microorganisms and they naturally exist in them. The most notable colorants obtained from animal sources are Natural Sepia (Cuttle fish), Crimson (Kermes Lotus), and Tyrian purple (Murexshellfish).

We all need food to survive and to maintain our health and as the population is increasing day by day, demand for food is also increasing. In modern days, consumer wants good food with appropriate quality, taste, and safety. For these improvements and increasing demand of food, food additives are required in our daily food for good quality to fulfil the demands of consumers. Ingredients or substance that added in a food for processing, preserve, or storage is called food additives. Food additives are of little or no nutritive values and it includes food coloring agents, flavoring substance, and food preservatives. Food additives are also used for enhancing the taste and appearance.

Table 1.1 Chemical classification of natural colorants.

Sl. no	Color	Chemical classification	Plant sources
1	Orange-yellow	Flavone dyes, isoquinoline dyes, polyene dyes, pyran dyes, chromene dyes	Marigold, β-carotene, lycopene, gentism, turmeric, saffron, Sanguinaria canadensis
2	Brown	Naphthoquinone dyes	Camellia thea, Lawsonia inermis
3	Red	Quinone dyes, anthraquinone dyes, chromene dyes	Annatto, Beta vulgaris, paprica, grapes vitacea, Alkanna tinctoria
4	Purple-blue	Benzopyrone dyes	Centaurea cyanus, Indigofera inctoria, Vaccinium myrtillus

      As we all need food for living and for good health, but the demand of food is increases with increasing population day by day. In modern days, consumer wants food with increasing standard of quality, taste, and safety. For this improvement, we added food additives in our daily food for good quality. So, when food is manufacture, it has to face many challenges which can be technologically fascinating.

      Food additives are used to prevent from spoiling and it also prevents the growth of bacteria, yeast, in food. The most commonly used additives are salt and sugar. Other examples of additives are ammonium carbonates, sodium nitrates, white sugar, potassium bromate, sodium benzoate, etc.

As with the time, people’s lifestyle changes, and nowadays, most of the people depends on the factory made food (also called processed food) rather than the homemade food. So, the factory made food should be balance its taste, appearance, texture, and its safety. The processed food should remain safe for long time after it has been made [15, 16]. The important roles of additives in our food are as follows:

      1 1. For improving quality of food, for example, preservatives.

      2 2. For giving the texture and consistency, for example, gelling and emulsifier.

      3 3. For improving the nutritional value in food, for example, sweeteners.

      4 4. For improving the flavor and taste, for example, acidulants and flavoring.

      5 5. For preserving the food from different types of bacteria or fungi, etc.

All additives are assigned by European wide basis. European wide regulates and controls the use of additives in food. All food additives are tested and must be shown to be safe before food manufacture able to use them. Food preservatives are a part of food additives as they come under the category of food additives. For example, chips packet are not completely filled up with chips but also contains almost half the packet of gas which is nitrogen gas used for preserving the chips. Table 1.2 shows the common color and associated food [20–25].

Table 1.2 Common color and associated food.

Sl. no.	color	Chromophore	Plant sources	Nutrients
1	Purple-blue	Anthocyanins	Eggplant, blackberry, purple cabbage, plum, blueberry, raisins, prunes, purple grapes, figs	Lutein, zeaxanthin, resveratrol, vitamin C, flavonoid, ellagic acid, quecertin
2	Green	Chlorophyll	Avocado, cucumber, spinach, kale, broccoli, snow pea, zucchini, artichoke, lettuce, kiwi	Lutein, zeaxanthin, resveratrol, vitamin C, calcium, folate, β-carotene
3	White-tan	Anthoxanthins	Cauliflower, mushrooms, parsnip, potato, ginger, onions, jicama, banana, garlic	Ancilin, potassium, selenium
4	Yellow-orange	Carotenoids	Papaya, pineapple, apricot, pumpkin, peach, carrot, orange, corn	β-carotene, zeaxanthin, flavonoid, vitamin C, potassium
5	Red	Lycopene or anthocyanins	Cranberry, beet, watermelon, tomato, strawberry, pomegranate	Ellagic acid, quecertin, hesperidin

      Food additives can be natural or artificial. Natural food additives are extracted from fruits, plants, etc., for example, beetroot powder which is used to as coloring agent, whereas artificial food additives are made synthetically, for example, vanillin which is used as flavoring agent in desserts [20].

      With time, the lifestyles of people are changing, and nowadays, most people depend on factory made food also known as processed food rather than using homemade food, for example, people prefer packed dairy products like paneer instead of making at home on their own. So, machine made food should have appropriate taste, appearance, texture, and its safety. Processed food should remain safe for longer time after it has been made.

      The important functions of food additives are as follows:

       • to prevent food from spoiling, for example, adding preservatives to food;

       • to give texture and consistency, for example, gelling and emulsifiers;

       • to improve flavors, taste, for example, adding flavoring agents to food;

       • to enhance the nutritional values, for example, sweeteners;

       • to make food attractive and appealing;

       • to garnish food;

       • to expand affordability and convenience;

       • to maintain the freshness of food.