Food Business Network News The color of natural foods is affected by the natural conditions of the outside world and the processing process. Sometimes it loses its natural color, which causes people to produce the illusion of food deterioration, and the value of the goods is greatly reduced. In order to make the appearance color of the food uniform, it is necessary to use various food colors 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. Synthetic pigments have been widely used because of their bright color, strong tinting strength, good stability, odorless and tasteless, soluble in water and color, uniform quality and low cost. There are many kinds of natural pigments, natural color, many varieties have both nutritional value, and some have therapeutic effects, especially the safety is trusted by people, and its use range and maximum dosage are more than artificial synthetic pigments. Natural colouring A natural pigment refers to a food coloring derived from natural resources and is a mixture of a plurality of different components. According to the natural pigment extraction method, it can be divided into the following four categories: 1. Liquid or solid pigments obtained by extracting juice or solvent from animals and plants 2. Powdery pigment obtained by drying and grinding colored colony 3. Pigment separated by a microbial fermentation into a liquid or further processed into a solid powder 4. A pigment obtained by processing a natural product as a raw material. Grape peel pigment The main component of the grape skin pigment is mallow pigment, which is usually extracted from the grape skin of the wine by sulfite solution, and the sulfuric acid content in the extract is 5X10-4-1X10-3. The pH value can affect the change of the hue, and the more acidic the color, the more vivid the red color. It is stable in an acidic environment and relatively unstable to light and heat. When used in a beverage, it is added in advance to enhance the color, and the quality can be prevented to a certain extent. Roselle pigment Roselle is an annual erect herb of the genus Hibiscus native to Africa, widely distributed in the tropical and subtropical regions of the world. The roselle flower bud is purple-red, and its pigment is anthocyanin. Its water extract is dehydrated with pectin extract, which has a unique acidity and can be used as a natural sour agent at the same time. The pigment property is similar to that of grape skin pigment. When used as a coloring of beverages, browning is likely to occur if the storage time is long. Safflower yellow pigment Safflower yellow is a water-soluble yellow pigment extracted from the petals of safflower of Compositae, which is stable to light and heat, and is not affected by pH. It can be used in beverages such as lemon. Due to its high hygroscopicity, special attention should be paid to the preservation of powdered pigments. caramel When a concentrated solution of a sugar or a sugar is heated to above 100 ° C, a caramelization reaction occurs to cause decomposition of the sugar, which is accompanied by brown color. The reaction can be carried out rapidly under the catalysis of an acid or a base. Due to the formation of 4-methylimidazole in the caramel produced by the ammonium process, some countries have banned the production of caramel by ammonium. Caramel with compatible properties should be used as much as possible. If the balance is destroyed, turbidity and precipitation will occur. The isoelectric point of caramel used in acidic beverages is often controlled to have a pH of 2 or less. Pay special attention to products containing tannic acid. Synthetic pigment Edible synthetic pigments generally refer to food colorings made from coal tar. The artificial synthetic pigments currently allowed in China are carmine, amaranth, lemon yellow, sunset yellow, indigo, bright blue and the like. Amaranth Amaranth is also called acid red, red bayberry red, cockscomb red, blue acid red, etc. It is a purple-red to dark red powder, odorless and soluble in water. The 0.01% aqueous solution is reddish purple, soluble in glycerin and propylene glycol, slightly soluble in ethanol, insoluble in oil, and easily decomposed by bacteria. It is stable to light, heat and salt, acid resistant, stable to citric acid and tartaric acid, and dark red in alkaline solution. It is not suitable for the use of fermented foods because it is sensitive to oxidation-reduction. Amaranth red pigment is suitable for fruity water, fruity powder, sherbet, soda, mixed liquor, concentrated juice, etc. The maximum use amount is 0.05 g/kg. If it is mixed with other pigments, it should be converted according to the maximum use ratio. Generally, it is first dissolved in water after being dissolved in the ingredients. Carmine Carmine is red to dark red granules or powder, odorless, red in water. It is soluble in glycerin, slightly soluble in ethanol, insoluble in oil, stable to light and alkali, but poor in thermal stability and resistance to reduction, and poor in bacterial resistance. When alkali becomes brown, at 20 °C 23 grams of water can be dissolved in 100 ml of water. It is used in the preparation of wine, sherbet and fruit juice. Due to poor light resistance, the finished products such as soda, juice and so on are too long to fade in the sun. The maximum usage is 0.05 g/kg. Lemon yellow Lemon yellow is also called tartrazine, acid yellow, and yellow. Lemon yellow is orange-yellow granules or powder, which is good in heat resistance, acid resistance, light resistance and salt tolerance. It is stable to citric acid and tartaric acid, red when it is alkali, and brown when it is reduced. The maximum amount used in the beverage is 0.1 gram. Sunset yellow Sunset yellow is also called sunset yellow, orange, sunset yellow, sunset yellow is orange-red particles or powder, odorless, soluble in water and glycerin, insoluble in ethanol, insoluble in oil, solubility in water at 0 ° C is 6.9% . It is light-resistant and heat-resistant. It is stable in citric acid and tartaric acid. It turns brown or brownish red when it is alkali. It is brown when it is reduced. It can be used alone or in combination with other pigments. The maximum usage is 0.1 g kg. Use of pigment 1. When using pigments, weigh accurately to avoid chromatic aberration. When changing to different strength pigments, it is necessary to determine the new addition amount after conversion and testing to ensure the consistency of the color tone of the products before and after. 2, the use of pigment powder directly, not easy to distribute evenly in food, may form color spots. Therefore, it is preferred to dissolve in a suitable solvent and use the pigment as a solution. It is generally formulated into a solution with a concentration of 1% to 10%. It is difficult to make the color uniform by an excessively concentrated solution. 3. The water used to prepare the synthetic pigment solution must be dechlorinated or deionized, because bleaching powder or sodium hypochlorite is commonly used in waterworks to purify water. Direct use can lead to dye fading. Water with high hardness causes difficulty in pigment dissolution. 4. When dissolving the pigment, the container used should be glass, ceramic, enamel, stainless steel and plastic utensils to avoid the influence of metal ions on the stability of the pigment. 5. The color types of synthetic pigments allowed in China are red, yellow and blue. The different chromatograms can be mixed in different proportions to meet the needs of beverage production. 6, a variety of synthetic pigments dissolved in different solvents, can produce different shades and strengths, especially when using two or several synthetic pigments color matching, the situation is more significant. For example, a certain proportion of a mixture of red, yellow and blue colors has a yellowish color in an aqueous solution and a reddish color in 50% alcohol. 7. Color matching should consider the effects of pigments and environment. For example, when indigo and red peony are mixed, indigo will make red blush faster. When citrine and indigo are colored together, if exposed to sunlight, indigo fades faster, while lemon yellow does not fade. 8. In the production of beverages, in order to avoid the influence of various factors on synthetic pigments, the addition of pigments should be placed as far as possible. 9. Water-soluble pigments should be stored in a dry and cool place due to their high hygroscopicity. When stored for a long time, it should be installed in a sealed container to prevent moisture deterioration. The unfinished pigments after unpacking must be resealed to prevent color changes due to oxidation, contamination and moisture absorption. Zhuhai Mingke Electronics Technology Co., Ltd , https://www.mingke-tech.com