In life, we all like beautiful things. When we choose food, we are also more attracted to foods with aromas and flavors. This makes the appearance of food especially important. So are the foods that are colorful enough to be pure natural? Of course, not.

The color of natural foods is easily affected by light, heat, oxygen and processing, and it is easy to lose its natural color. However, the appearance of food will ultimately affect consumers' choices, which will directly reduce the value of goods. Therefore, in order to make the appearance color of the food uniform, various food colors are often used to improve the appearance of the food and improve the commerciality of the product. Food coloring can be divided into two major categories: natural pigments and synthetic pigments. Natural pigments have natural color, many varieties have both nutritional value, and some have therapeutic effects. However, natural pigments have poor stability, easy to fade, are not easy to dissolve, resulting in uneven dyeing, and limited yield, resulting in high extraction costs. The use in the processing industry is also subject to significant restrictions. Since the 1950s and 1960s, with the development of chemical industry and food industry technology, a variety of artificial colors have been obtained through chemical synthesis. Most of the synthetic pigments are coal tar aniline dye compounds, which are structurally divided into azo pigments (amaranth, carmine, sunset yellow, lemon yellow, etc.) and non-azo pigments (red erythro, bright blue, Indigo, etc.). Synthetic pigments have the characteristics of bright color, strong tinting strength, good stability, odorless and tasteless, soluble in water and color, uniform in quality, low in cost, etc., and have been widely used in the food industry.

The artificial synthetic pigments currently allowed in China include erythrosine red, quinoline yellow, tartrazine, sunset yellow, amaranth, carmine, new red, temptation red, azo red, bright blue and indigo [1]. The standards for the use of food coloring in China are based on strict animal toxicity tests by national specialized agencies and are safe to use within the scope of application and limited standards. Due to the different cultural backgrounds and technological developments of different countries, there are certain differences in the varieties, application scope and limit standards of food coloring. When the world uses the most synthetic pigments, there are more than 100 varieties, and the United States is currently only left. Seven species are legally recognized by the FDA, while some EU countries such as Sweden, Norway, and France ban the use of azo-based pigments. In Norway, it is completely forbidden to add any chemical synthetic pigments to foods. In recent years, the issue of the safety of artificial food coloring has received great attention worldwide, especially the impact on children is the focus of attention.

Children's organs are developing and are more susceptible to toxic substances. Studies have shown that excessive consumption of colored snacks containing artificial colors directly affects children's health and development. In 2004, researchers at Columbia University conducted a comprehensive analysis of previous studies on pigmentation and children with ADHD. The results showed that there was a certain correlation between synthetic pigment and ADHD [2]. In 2007, the University of Southampton, UK, requested the British Food Standards Agency to conduct research on the effects of artificial artificial coloring on children's development, and published the relevant research results in the famous journal Lancet. The study included 153 children aged 3 years and 144 children aged 8-9 years old. They were randomly divided into groups containing mixture A (lemon yellow, carmine, sunset yellow, azo red and sodium benzoate), mixture B (sunset yellow, even) Nitrogen red, quinoline yellow, tempting red and sodium benzoate) and fruit juice without mixture, the results showed that children in the experimental group showed hyperactivity, agitation, inattention and other problems [3]; children fed synthetic pigments have not yet A well-developed liver and kidney increase the burden, which interferes with normal metabolism in the body, diarrhea, bloating, abdominal pain, malnutrition and various allergies such as rash, urticaria, asthma, rhinitis, etc. Although the European Food Safety Authority (EFSA) pointed out the limitations of the above studies in the evaluation of artificial pigment safety, including the small sample size and insufficient evidence, it is also believed that children aged 1-10 will indeed have With a higher risk of disease, the European Food Safety Authority believes that artificial pigmentation should be strengthened in order to increase the protection of children's health. Due to concerns about the potential hazards of synthetic pigments to children, since 2008, many consumer organizations in Europe have urged the EU to completely ban six synthetic pigments, namely, evening yellow, blue acid red, lemon yellow, carmine, quinoline yellow and brilliant red. [4] Although it has not been implemented yet, it has also proved that the safety of synthetic pigments in children is getting more and more attention.

If the artificial synthetic pigments are reasonably added in strict accordance with the National Food Safety Standard, the safety is still controllable, but some unscrupulous merchants add synthetic pigments in violation of regulations, including increasing the use of food coloring and adding non-food coloring in foods. The consequences are worrying. The issue of food safety in China has become more prominent in recent years. The current Sudan Red incident has been illegally added to non-edible artificial colors in food. Sudan red belongs to azo pigments and is extremely harmful to human health. Studies have confirmed that azo compounds form an aromatic amine compound after decomposition in the body, and aromatic amines are known to cause canceration of multiple target organs. Studies have confirmed that azo pigments can bind to human serum albumin and DNA [5,6] to play a toxic role. Long-term intake of azo pigments in rats and liver tissue pathological changes, reproductive toxicity to animal organisms , genotoxicity and carcinogenic, mutagenic effects [7]; foods containing temptation red can cause damage to the DNA of the feeding mice [8]; lemon yellow and acid red also have adverse effects on liver and kidney function in rats [9] Scientists in the former Soviet Union conducted long-term animal experiments on amaranth, and found that the carcinogenic rate was as high as 22% [10].

Children have a natural love for bright and sweet foods, and often cause excessive consumption without being restrained. Therefore, when we choose foods, especially children's foods, we should carefully check the product labels, try to choose foods produced by regular enterprises with quality assurance; in addition, we must restrain the children and avoid eating too many foods containing artificial colors in a short period of time. It causes excessive consumption of artificial pigments and affects health; the adverse effects of artificial pigments on the body are reduced to a controllable safety range.