Food additives refer to chemical synthetic or natural substances added to food in order to improve the quality, color, aroma, taste and shape of food and meet the needs of preservation and processing technology. The raw materials for processing green food come from certified green food producing areas, and food additives must be reasonably selected and limited in the processing process to prevent secondary pollution to green food.
Key words: food additives, quality, color, fragrance, taste, deterioration, production technology, nutrition
Green food refers to pollution-free, safe, high-quality and nutritious food produced according to the principle of sustainable development and approved by specialized agencies. Food additives refer to chemical synthetic or natural substances added to food in order to improve the quality, color, fragrance, taste and shape of food and meet the needs of preservation and processing technology. In addition, food nutrition fortifiers also belong to the category of food additives. Food nutrition fortifier refers to a substance added to food to enhance nutritional components.
Raw materials for processing green food come from certified green food producing areas. In the process of processing, food additives must be reasonably selected and limited to prevent secondary pollution to green food. The purpose of using food additives in green food production is:
(1) Maintain and improve the nutritional value of products, and supplement or improve the flavor and color lost during processing;
(2) improving the storage resistance and stability of the product;
(3) improve the finished product, quality and sense, improve the processing speed, and facilitate production and operation.
First, food additives improve the quality of green food
There are seven kinds of additives that can improve the quality of green food, namely emulsifier, thickener, water-retaining agent, flour treatment agent, stabilizing coagulant, leavening agent and gum base agent.
1. Emulsifier refers to a substance that can make two or more mutually immiscible liquids (such as oil and water) uniformly disperse into emulsion (also called emulsion). The definition of FDA in the United States is: "It can change the surface tension of components in an emulsion and make it a stable and highly viscous substance."
(1) Types of emulsifiers in green food production:
(1) by source
(2) Classification by dissociation type
(3) Classification by function
(2) Emulsifiers used in green food include sucrose fatty acid ester, sodium caseinate, glycerol monostearate, sodium stearoyl lactate, propylene glycol fatty acid ester, lecithin, modified soybean lecithin and rosin glyceride.
2. Food thickener is a kind of substance that can improve the physical properties of food, increase the viscosity of food or form gel, endow food with viscosity and suitable taste, and improve emulsion and stability of suspension.
Classification of thickeners in green food;
(1) by source
(2) Classification by ion type
(3) Classification by chemical structure
(4) Classification according to gel properties
3. Water-retaining agent, also known as water-retaining agent and quality improver, is a food additive used to improve the quality of various foods in food processing. It has the following functions in food processing:
(1) Increase the water retention and hygroscopicity of meat products, improve the elasticity of products, avoid the loss of soluble nutrients, and enhance the tenderness of food;
(2) Enhance the fat emulsification of dairy products, and keep the products with uniform texture and delicate taste;
(3) Enhance the water retention, moisture absorption, adhesion and other functions of bread and cakes, so as to avoid the dry surface of products and the difficulty of loosening and shedding tissues;
(4) It can thicken jam, change rheological properties and improve taste;
(5) The improvement of flour enhances the strength and stability of gluten;
4. Flour treating agent is a food additive, which is used to whiten flour and improve the quality of baked products. Most flour treatment agents are chemically synthesized products, so they should be used with caution in green food.
There are several flour treatment agents commonly used in grade A green food: azoformamide, L- cysteamine hydrochloride, magnesium carbonate, calcium peroxide and active gluten.
The banned flour treatment agents are benzoyl peroxide and potassium bromate.
5. Stabilizers and coagulants are a kind of food additives that can stabilize the food structure, or keep the food structure unchanged, solidify protein or prevent fresh fruits and vegetables from softening.
The types of stabilizers and coagulants include coagulants, fruit and vegetable hardeners, chelating agents, canned deoxidizers, humectants and clarifiers.
6. The leavening agent is the main additive in the production of cakes and biscuits, also known as leavening agent or loosening agent.
The types of leavening agents used in green food are: alkaline leavening agent, acidic leavening agent, compound leavening agent and biological leavening agent.
7. Gum base is a substance that endows chewing gum with foaming, plasticizing and chewing resistance. Generally, it is mainly composed of natural rubber, synthetic rubber and other polymer colloidal substances, plus softeners, fillers, antioxidants, plasticizers and so on.
Second, food additives improve the color of green food
The first important sensory stimulation of food is color, and the color of food can stimulate people's vision best. It is an important factor to evaluate the sensory quality of food, just like the fragrance, taste and shape of food. Additives used to enhance, adjust and improve color in green food processing mainly include colorants, color fixatives and bleaches.
1. Colorants are substances that can color and improve the color of food, usually including edible synthetic pigments and edible natural pigments. The allowable colorants in AA and A grade green foods are: corn yellow, beet red, turmeric and curcumin, safflower yellow, shellac red, cranberry, paprika red, tea yellow pigment, red rice red, chrysanthemum yellow extract, black bean red, sorghum red and chlorophyll.
2. Color fixative is a kind of chemical substance without pigment, which can make food processed as scheduled and will not decompose and destroy during storage. Common color fixatives for common foods include potassium nitrite, sodium nitrite, sodium nitrate and potassium nitrate. Common color fixatives include L- ascorbic acid and its sodium salt, isoascorbic acid and its sodium salt, nicotinamide and so on. But potassium nitrite, sodium nitrite, sodium nitrate and nitrate are forbidden in green food.
3. Bleach is a substance that destroys and inhibits the color factor of food, makes it fade or prevents food from browning. At present, the bleaches allowed to be used are all chemical synthetic products and cannot be used in AA-grade green food. At present, it is stipulated that all grade A green foods can be used except sulfur, but the dosage should be strictly controlled and the relevant regulations of the state should be paid attention to.
The commonly used bleaching methods in food industry include reduction bleaching, oxidation bleaching and decolorization bleaching, including fumigation, which can not only bleach but also inhibit browning.
Three, enhance the aroma of green food food additives
The aroma in food is mainly formed through three ways. First, it naturally exists in food raw materials, that is, it is formed during the growth of raw materials; Second, it is formed by aroma precursors in food raw materials during processing and storage, and third, it is added during food processing.
All natural or synthetic substances that can stimulate people's olfactory organs and cause pleasure are collectively called spices. Spices that can be used to prepare food flavors are called food flavors.
Spice classification:
(1) provided by spice source.
(2) according to the perfume composition
(3) According to the types of spices: citrus, fruits, mint, beans, spicy, milk, meat and nuts.
(4) According to the form of spices.
(5) according to the use of spices.
Fourth, adjust the taste of green food food additives
The flavor of food is one of the important factors caused by the stimulation of food ingredients to taste receptors. Food additives to adjust the taste of green food mainly include sweeteners, acidity regulators and flavor enhancers.
Sweetener refers to an additive that can give food sweetness.
Sweetener classification:
(1) by source
(2) according to the nutritional value
(3) Classification according to chemical structure and basic characters.
2. Acidity regulator, also known as pH regulator, is a substance used to maintain or change the acidity of food, which can be used as both processing aid and final ingredient in processed food. Acidity regulators are usually divided into acidulants, alkalis and salts.
Classification of acid agents:
(1) can be divided into sour taste, sour taste, astringent taste, pungent taste and umami taste.
(2) according to the kind of acid
(3) according to the source of the acid
3. A flavor enhancer is a food additive that supplements or enhances the original flavor, also known as a flavor enhancer. Umami is the feeling of some amino acids, nucleotide amides, trimethylamine, peptides, organic acids and other substances that are possessed by food raw materials or produced by processing and heating decomposition on taste buds.
Classification of umami agents:
(1) According to the basic chemical properties
(2) according to their sources
Five, to prevent the deterioration of green food food additives
One of the key problems in green food processing is preservation.
1. Preservatives are additives used in food, which are used to prevent food from deteriorating during storage and circulation, mainly caused by microbial reproduction, improve preservation and prolong use value. Preservatives are mostly substances that can kill microorganisms or inhibit their reproduction.
Types of preservatives:
(1) According to the main functional characteristics of microorganisms
(2) According to the components
(3) according to the characteristics of preservatives
2. At present, many natural preservatives have been developed, which have the characteristics of strong antibacterial activity, safety, non-toxicity, good water solubility, good thermal stability and wide range of action, mainly including lysozyme, chitosan, natamycin, sodium diacetate, nisin, polylysine and protamine.
3. Green food antioxidants refer to food antioxidants that can prevent or delay the oxidation of green food, improve the stability of green food and extend the shelf life after being added to green food.
Classification of antioxidants:
(1) According to solubility.
(2) By source
(3) According to the action mechanism, there are: free radical absorber, metal ion integrator, oxygen scavenger, singlet oxygen quencher, methyl siloxane and sterol antioxidant, peroxide decomposer, ultraviolet absorber, multifunctional antioxidant and enzyme antioxidant.
Six, improve the food additives in the process of green food production.
These food additives usually have some unique functions, such as catalysis, defoaming, filtering, molting, coating, anti-caking, adsorption, etc., which can optimize production technology, improve production efficiency and improve product quality. These additives mainly include enzyme preparation, coating agent, defoaming agent and anti-caking agent.
Seven, strengthen the nutrition of green food food additives
Additives that emphasize the nutrition of green food are called nutritional fortifiers. Food nutrition fortifier is a natural or synthetic food additive added to food to enhance nutritional components. These food additives can be divided into three categories according to their properties: amino acids, vitamins and inorganic salts.
Functional nutritional fortifier is the demand for improving the nutritional health level of Chinese people and developing high-quality green food, such as functional sugar alcohols, active peptides and proteins, fungal polysaccharides, special essential fatty acids and trace active elements.
Prospect of green food additives;
The market of food additives has a bright future. China is rich in plant resources. At present, China's natural extracts such as tea polyphenols, natural sweeteners such as licorice extract, natural antibacterial agent allicin, natural pigments and natural spices are favored by the international market. In the future, we should take advantage of this advantage, increase the application of high-tech extraction technology and upgrade the grade of food additives in China.
Although the production capacity and output of food additives in China are increasing rapidly at present, some products are still in short supply. In the future, according to the domestic food consumption structure, we should focus on developing some efficient, commonly used and new varieties, such as molecular distilled monoglyceride and sucrose ester series products in emulsifiers; Various small-tonnage vitamins and soybean extracts such as soybean isoflavones in nutritional fortifiers; Oligosaccharides and fructose syrup in sweeteners; Propionates and esters, food-grade sodium diacetate, sodium isovitamin C, catechol, etc. Among anti-corrosion antioxidants; Modified starch in thickener.
With the continuous improvement of people's living standards and the rapid development of food industry, the types and dosage of food additives are increasing and the application scope is expanding. Food additive industry has become an independent industry and an important part of modern food industry, with huge market space and broad development prospects.