Knowledge of the use of colorants, color protectants and bleaching agents

Colorants
Color and luster are important sensory indicators for evaluating the quality of food;
Whether the color is normal or not is an important basis for judging the quality of food;
Foods with pleasing color and luster can win a good first impression.
Colorant is to make the food color and improve the color of food substances.
I. Food and Color
The color of food and its acceptability.
It is the first feeling
It is one of the indicators to judge whether the quality of food is good or bad freshness
The value of food ingredients is determined by their color and luster
However, in food processing, the natural pigments in food will be discolored or faded, so in order to restore or improve the color of food, it is necessary to use coloring agents.
Color and luster give flavor associations. The ability of a food product to be attractive and give a sense of taste in terms of color largely determines the marketability and evaluation. Common colors act on the senses in the following general ways:

Green and blue: give a person a fresh, refreshing feeling, mostly used in alcohol, convenience dishes, beverages and other foods. But there is a raw, cool, sour feeling, so non-vegetable canned food, snacks and pastries, etc. generally do not use these colors.
Red: give people a strong taste of mature and delicious feeling, and more bright and eye-catching, can stimulate the consumer’s desire to buy, so many candies, pastries, etc. are used in this type of color.
Orange: is a mixture of yellow and red color, both red and yellow advantages of the two colors, giving a strong sense of sweetness, maturity and mellowness, beverages and canned food and other foods are used.

Coffee color: it gives a feeling of unique and strong flavor. Coffee, chocolate, beverages, pastries, beer and tea are often used.
Yellow: gives a person the feeling of aroma, ripe and delicious, appetite, baked goods, canned fruits and margarine and other foods are often used.
Second, coloring agent classification
(A) food synthetic coloring
Food synthetic coloring is an artificial chemical synthesis of organic pigments. At present, the world allows the use of synthetic pigments are almost exclusively water-soluble pigments, in addition to their respective color precipitates.

Color precipitation is by water-soluble pigments precipitated in the permitted use of insoluble substrate (usually Al2O3) prepared by the special coloring agent, suitable for a variety of powdered foods, snack foods, gummies, candies (especially with titanium dioxide formulated as a suspension of coated or sliced confectionery) and a variety of pressed food.
China’s permitted use of synthetic food coloring are: amaranth red, carmine, erythrosine, new red, seductive red, lemon yellow, sunset yellow, bright blue, indigo and their respective aluminum precipitates, as well as β-carotene, sodium copper chlorophyll and titanium dioxide.
(ii) Edible natural colors
Edible natural pigments are from natural substances, the use of certain processing methods to obtain organic coloring agents, there are many varieties.
Plant pigments: such as green (chlorophyll), orange (carotene), red or purple (anthocyanin);
Animal pigments: e.g. red pigments in muscle, carotenoids in shrimp and crab skin;
Microbial pigments: e.g. erythroxanthin.
Advantages: security than synthetic pigments, so the recent development is rapid, countries licensed to use the varieties and the amount are increasing.
Disadvantages: pigment content and stability are not as good as synthetic products.
Development trend: Although synthetic products in the permitted scope of use and the amount of use, will not bring harm to human health, but in the reverence for natural and return to nature today, the use of chemicals is declining year by year, and natural coloring agents are becoming more and more popular.

Translated with DeepL.com (free version)