What are the performance characteristics and applications of commonly used food additives?

Food additives are an important factor in the modern food industry, and play an extremely important role in improving the color, aroma and taste of food, increasing food nutrition, improving food quality, improving processing conditions, preventing food deterioration, and extending the shelf life of food. Therefore, the food additive industry occupies an important position in the modern food industry.
Definition and Role of Food Additives
1, the definition of food additives food additives, food additives, in order to improve the quality of food and color, aroma and taste, as well as for the preservation and processing technology needs to be added to the food of synthetic or natural substances.

2, the role of food additives and development trend 1) the main role of food additives a) can improve the quality of food, improve the quality of food, to meet the requirements of people on food flavor, color, texture;
b) It can make the food processing and manufacturing process more reasonable, more hygienic, more convenient, and is conducive to the mechanization, automation and scaling up of the food industry; c) It can enable the food industry to save resources, reduce costs, and greatly enhance the quality and grade of food at the same time, increase its added value, resulting in significant economic and social benefits.
2) The development trend of food additives a) Develop natural, nutritious and multi-functional food additives;
b) Commitment to the development of diversified, specialized additives.
Types of food additives
Food additives can be divided into natural food additives and synthetic food additives according to their sources. Classified by function, there are: nutritional enhancers, anticorrosive and antifungal agents, antioxidant and preservative, thickeners, emulsifiers, chelating agents (including stabilizers and coagulants), quality improvers, flavoring agents, color treatments, edible flavors, spices and so on.

1, food preservatives food preservatives are to inhibit food spoilage and deterioration, to extend the storage period and freshness of a class of additives. Currently used food preservatives are mainly 4 types: benzoic acid and its salts, sorbic acid and its salts, propionic acid and its salts, parabens.

1) Benzoic acid and its sodium salt benzoic acid, also known as benzoic acid, is a commonly used organic fungicide. In low pH environments, benzoic acid is effective against a wide range of microorganisms, but weak against acid-producing bacteria.
It is ineffective against many molds and yeasts when the pH is above 5.5. The optimum pH of benzoic acid for bacterial inhibition is 2.5-4, and the minimum mass fraction for complete inhibition of general microorganisms is 0.05% to 0.1%.

(2) Sorbic acid and its salts sorbic acid chemical name 2,4 a hexadienoic acid, is a broad-spectrum food preservatives.

(3) propionic acid and its salts propionic acid is similar to acetic acid stimulate the sour flavor of the liquid, due to the normal intermediates of human metabolism, it is non-toxic, its ADI value is not restricted.
Propionic acid is effective against molds, aerobic bacteria, gram-negative bacteria, especially against Bacillus coli which makes bread produce filamentous mucus, and prevents aflatoxin production, so it is commonly used in the production of bread and pastries. Propionates have the same preservative effect, and are commonly used as calcium and sodium salts.

(4) Parabens and its esters Parabens, also known as nipagin esters, are colorless crystals or white crystalline powder, tasteless and odorless. It is mainly used in soy sauce, jam, refreshing drinks and so on.
The anticorrosive effect is better than benzoic acid and its sodium salt, the use of about 1/10 of sodium benzoate, the appropriate pH value of 4-8. The toxicity of parabens is lower than that of benzoic acid, and its water solubility is poor, commonly used in alcohols to dissolve first before use, and the price is also higher.

(5) Natural food preservatives natural preservatives have the advantages of strong antibacterial, safe and non-toxic, good water solubility, good thermal stability, wide range of effects, etc., not only harmless to human health, but also has a certain nutritional value. In recent years, the research and development of natural preservatives are: natamycin, glucose oxidase, fish protein, lysozyme, polylysine, chitosan, pectin decomposition, propolis, tea polyphenols and so on.

2, food emulsifiers and thickeners food emulsifiers and thickeners are to improve and stabilize the physical properties of food components or to improve the organization of food additives, food “shape” and “quality” and food processing performance has an important role.

(1) emulsifier where a small amount is added to make immiscible liquids (such as oil and water) to form a stable emulsion of food additives known as emulsifiers.

(1) Fatty acid esters of glycerol
Glycerol and fatty acid reaction, can generate single, double and triple ester. Single fatty acid esters of glycerol, referred to as monoglycerides, is an important food emulsifier, widely used in shortening, pastry, bread, candy, ice cream, emulsification, foaming, anti-crystallization, anti-aging effect.
Sucrose fatty acid esters
Sucrose fatty acid ester is an emulsifier with excellent performance, high efficiency and safety. Sucrose fatty acid ester is hydrophilic in sucrose part and lipophilic in long carbon chain fatty acid part, which can be digested into sucrose and fatty acid in the body and absorbed. Sucrose fatty acid esters are non-toxic, non-irritating and easily biodegradable, so there is no restriction on their use in food.

③Sorbitol fatty acid esters with lost water
Sorbitol fatty acid esters are sold under the trade name of Span. Span emulsifiers react with ethylene oxide in an addition reaction catalyzed by alkali to obtain Tween emulsifiers.

④Soy lecithin
Soy lecithin, also known as soy lecithin or phospholipids, is a yellowish or brown transparent, translucent viscous material. He is a by-product of soybean oil production, is a natural surfactant. Its main components are lecithin, ceruloplasmin and inositol phospholipids. Soy lecithin as an emulsifier, with excellent emulsification, antioxidant, dispersion and moisturizing properties, has been widely used in food, instant milk, margarine, granular beverages, nutritional emulsifiers and so on.

(2) Thickeners Thickeners are a class of food additives that can increase the viscosity and change the properties of food.

Gelatin
Gelatin is white or yellowish, translucent, slightly glossy flakes or fine particles, its main component is protein, is made of animal skin, bone, cartilage and other collagen contained in the partial hydrolysis of polymer polypeptide polymers. Gelatin gel is tough, elastic, good pressure, dissolved in 30 ℃ water, cooling gel into a colloid.
②Maltodextrin
Maltodextrin, also known as water-soluble dextrin or enzymatic dextrin, is based on various types of starch as raw materials, low degree of controlled hydrolysis by enzymatic processes, purification, drying and become. Maltodextrin is widely used in candy, cream of wheat, fruit tea, milk powder, ice cream, beverages, canned food and other foods, is a variety of food fillers and thickeners.
③Pectin
Pectin is a kind of polysaccharide substance widely existed in plant tissues, and its main component is galacturonic acid, which is recommended by FAO/WHO Joint Committee on Food Additives, and is not subject to the limitations of the amount of food additives recognized as safe. The main raw material for the production of pectin is citrus peel.
④Carrageenan
Carrageenan is a natural plant gum extracted from red algae, and is the youngest of the three major algal gums: fucoidan, agar, and carrageenan, whose main components are D-galactose and L-galactose. Carrageenan is extracted from raw materials such as kirin, salsify and carob. Carrageenan used in the food industry mainly has the properties of gelation, viscosity, stability, emulsification and suspension, etc. It is widely used in dairy products, ice cream, juice drinks, bread, water gels (see curry, etc.), meat products, canned food and other foods.
⑤ Xanthan Gum
Xanthan gum is a safe, non-toxic, tasteless new food additives, with excellent thickening, suspension, emulsification, stabilization and other functions. Xanthan gum is an extracellular heteropolysaccharide produced by Xanthomonas campestris through a series of biochemical reactions with starch as the main raw material. Its main components are glucose, mannose, glucuronic acid and so on, and its molecular weight is up to millions, which is the most commercially valuable, the largest production and the most widely covered market among the domestic and foreign microbial polysaccharides products at present. Xanthan gum has excellent thickening properties, using a very low concentration, it can achieve the required viscosity. Xanthan gum and high concentrations of sugar or a variety of salts can form a stable thickening system.

3, flavoring agent flavoring agent mainly sour agent, sweet agent, salty agent and bitter agent. One of the bitter agent application is very little, salty agent (generally use salt) our country and not as a food additive management. The following mainly introduces acidulants, sweeteners.

(1) acidulants to give food acidity as the main purpose of food additives called acidulants. Acid can promote saliva, gastric juice, bile and other digestive secretion, with the promotion of appetite and digestion, its main role is to regulate the pH value of food, used as an antioxidant synergist, to prevent food rancidity or browning, to inhibit the growth of microorganisms and to prevent food spoilage and so on. Acidulants are mainly organic acids: citric acid, lactic acid, tartaric acid, malic acid, fumaric acid and adipic acid; inorganic acids: edible phosphoric acid, carbonic acid and so on.

Citric acid
Citric acid is colorless transparent crystals or white powder, with a mild and refreshing sour taste, commonly used in a variety of beverages, soft drinks, wine, candy, snacks, cookies, canned fruit juices, dairy products and other food manufacturing.

②Malic acid
Malic acid chemical name for carboxybutanedioic acid or hydroxysuccinic acid, is a white or fluorescent white solid. He has a special malic acid flavor, widely used in yogurt, soda, ice cream, chewing gum, ketchup, jam, vinegar, fruit wine, margarine and so on. Malic acid is better than citric acid, with a strong acidic flavor, a taste close to natural fruit juice, and a good pH adjustment effect. Use him instead of citric acid as acidulant, the amount can save 20%, and can cover some of the cane sugar substitutes produced by the odor.

(2) sweetener sweetener is to give food sweetness for the main purpose of food additives. According to its source can be divided into two categories of natural sweeteners and synthetic sweeteners. Natural sweeteners are divided into sugar and sugar derivatives, non-sugar natural sweeteners. Synthetic sweeteners are mainly some of the sweet chemical substances, sweetness is generally tens to hundreds of times higher than sucrose, most do not have nutritional value.

Saccharin and Sodium Saccharin
The chemical name of saccharin is phthaloylbenzimide, no calories, high sweetness, saccharin sodium sweetness is 300-500 times that of sucrose, is an early development of a chemical synthetic sweeteners. the early 20th century began to be used in food, our country has more than 60 years of production and use of the history of production capacity of 40,000t/year, the world’s major exporting countries.

② Xylitol
Xylitol is a sugar alcohol made from wood, corn cobs and other materials in the reduction of xylose or polyxylan. Xylitol is a white crystalline or crystalline powder, with a cool sweetness, sweetness of sugar 65% to 100%, heat 12.5kJ / g, higher than other sugar alcohols, the formation of dental caries inhibition of the effectiveness of the activities of the bacterium Aspergillus. Xylitol in addition to the commonality of sucrose, glucose, but also has a special biochemical properties, he does not need to pass insulin can be absorbed by the body through the cell wall, and has the function of lowering blood lipids, ketone bodies and other functions, can be used for the production of beverages, confectionery, canned food and other foods.

③ Stevioside
Stevioside is a colorless or yellowish needle crystal with melting point 196℃～198℃, it is a mixture of many kinds of glycosides extracted from plant stevia, which is relatively safe and the sweetness is about 300 times of sugar. Its taste is similar to that of sucrose, with pure sweetness, long retention time and delicious aftertaste. It is stable to heat, acid and alkali, and is an ideal low-energy sweetener.

④Maltitol
The sweetness of maltitol is 0.8 to 0.9 times that of sucrose, and it does not produce heat after intake, nor does it synthesize fat and stimulate the formation of cholesterol. Pure maltitol is chemically very stable, with better heat and acid resistance than sucrose, sorbitol and xylitol. Maltitol is able to resist the digestive action of gastric juice, the hydrolysis of small intestinal enzymes, and the decomposition of large intestinal microorganisms in the human digestive process. This special physiological performance makes maltitol a high-grade health care sweetener with excellent taste and no calories.

⑤ Aspartame
The chemical name is aspartyl phenylalanine methyl ester, the relative molecular mass is 294.31. aspartame is a new type of amino acid sweetener, the appearance of white crystals or crystalline powder, pH: 4.5-6.0. aspartame has a pure sweetness like sugar, the sweetness is 200 times of sucrose, there is no odor, and it has an effect on the flavor of food. It has good safety performance, its metabolism in the body does not need the participation of insulin, it can be digested and absorbed quickly, and it does not cause dental caries.

⑥ Acesulfame
The chemical name is potassium acetylsulfamate, molecular weight 201.24. Acesulfame is a white crystalline powder with high sweetness, which is about 200 times sweeter than sucrose (mass fraction 3% solution).

⑦Other sweeteners
Mainly oligofructose, erythritol, sweetener, somatosweet and so on.

4, food coloring additives used for food coloring is called food coloring, its purpose is to increase the appetite for food and stimulate appetite. According to the source of food coloring is divided into synthetic coloring and natural coloring two categories.

(1) synthetic pigments synthetic pigments are amaranthine red, carmine, erythrosine, new red, lemon yellow, sunset yellow, indigo yellow, bright blue, as well as for the enhancement of the above water-soluble acidic pigments in the oil dispersion of a variety of pigments in the aluminum precipitate.

Carmine
Carmine is a red to deep red powder. It is characterized by acid resistance, good light resistance, but heat resistance, poor resistance to reduction, turn brown when alkali, mostly used in confectionery, beverages, livestock and aquatic products processing.

② lemon yellow
Lemon yellow is an orange-yellow powder, countries are allowed to use a wide range, mainly for confectionery, beverages, livestock and aquatic products processing, medicine and cosmetics. Characterized by heat resistance, acid resistance, light resistance and salt resistance are good, poor oxidation resistance, slightly reddened by alkali, restore the color faded.

(2) natural pigments natural pigments are extracted from plant and animal tissues with solvents. Although the color of natural pigments is a little inferior to light, heat, pH and other stability is relatively poor, but the security than synthetic pigments to be higher, and rich sources, some natural pigments also have vitamin activity or some kind of pharmacological function, is increasingly being attached importance to people, the production, sales volume is growing rapidly. The main products of edible natural coloring in China are: caramel, red yeast rice and red yeast rice powder, red yeast red, chili oil resin and chili red, mast yellow, mast blue, beet red, wormwood red and so on.
General Requirements and Safe Use of Food Additives
With the development of food toxicology, food additives originally considered harmless have been found in recent years to have chronic toxicity and teratogenicity, mutagenicity, carcinogenicity hazards, so countries pay full attention to this.
At present, both international and domestic food additives are subject to strict management, enhanced evaluation and restricted use. In order to ensure the safety of food additives, food additives should follow the following principles:
① Safety Evaluation. Evaluation of the toxicity of food additives (or safety) of the first standard is the ADI value (human daily intake), the evaluation of the safety of food additives, the second commonly used indicators is the LD50 value (half lethal dose, also known as lethal dose).
② use regulations. GB2760-2014 national standards for food safety, food additives use standards, stipulates the principle of use of food additives, permitted use of food additives varieties, the scope of use and the maximum amount of use or residue.