Views: 0 Author: Site Editor Publish Time: 2021-03-30 Origin: Site
Natural preservatives have the incomparable advantages of synthetic preservatives, such as strong antibacterial properties, safety and non-toxicity, good water solubility, good thermal stability, and wide range of action. Since natural preservatives are natural substances, and some of them are components of food, they are non-toxic to the human body and can improve the flavor quality of food. They are a kind of food preservatives with development prospects.
Protamine
Protamine is a small and simple high-arginine-containing strong alkaline protein found in fish sperm cells. Protamine shows strong antibacterial ability in neutral and alkaline media. High thermal stability, heating at 210 ℃ for 1.5h is still active, while the scope of antibacterial and food preservation are wide. Studies have found that protamine can interact with certain proteins in cell membranes involved in nutrient transport or biosynthesis systems, impairing the function of these proteins, and then inhibiting cell metabolism and causing cell death. The antibacterial effect of protamine in neutral and alkaline media is more significant. It is widely used in the preservation of bread, cakes, food products (prepared dishes), aquatic products, bean paste, seasonings, etc.
Propolis
Studies have shown that propolis contains a large number of active reducing factors. Because of its strong antioxidant properties, it can be used as a natural antioxidant for oils and other foods; propolis polyphenol compounds have the effect of inhibiting and killing bacteria, and after degradation The final product is benzoic acid, which is a natural preservative; propolis can also be used as a natural food additive to improve the taste and color of food; it can be used as a food function enhancer to enhance the health effect of food. In recent years, research has also found that propolis It is not only widely used in food, but also has strong medical care value. Propolis can be processed into natural chewing gum after a special process. The active ingredients in it can clean and protect teeth, prevent the formation of dental caries, and gradually eliminate tartar.
Chitosan
Chitosan, also called chitin, is a polysaccharide substance deacetylated from chitin from crabs, shrimps, insects, etc. It has a strong inhibitory effect on Escherichia coli, Proteus vulgaris, Bacillus subtilis, and Staphylococcus aureus. Affect food flavor. It is widely used in preserved foods, raw noodles, rice, bean paste, seasoning liquid, strawberries, etc.
Tea polyphenols
A large number of experiments have shown that tea polyphenols have a good antiseptic and fresh-keeping effect. Tea polyphenols are effective against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, tomato ulcers, Streptococcus caries, as well as Mucor, Penicillium, Gibberella, Anthrax. Saccharomyces cerevisiae has an inhibitory effect. Moreover, tea polyphenols have a good physiological effect on the human body after being taken into the human body; it can remove excess free radicals in the human body, improve the permeability of blood vessels, strengthen blood vessel walls, lower blood pressure, prevent blood sugar from rising, and promote vitamin C. Absorb and assimilate, regulate the microorganisms in the human body, inhibit the growth of bacteria, and have the effects of anti-cancer, anti-caries, anti-body lipid oxidation and anti-radiation.
Essential oil
Essential oils refer to extracts from the roots, bark, seeds or fruits of aromatic plants that generally grow in the tropics. As early as prehistoric times, essential oils have been used as condiments and food additives, and used in medicine and preservation of corpses. In recent decades, there have been many reports on the effect of essential oils in inhibiting microorganisms and as food preservatives. In addition to the essential oils of laurel, cinnamon, garlic, pepper, onion and other plants that can be used as natural preservatives, there are also reports that the anethole in the volatile oil of anise can inhibit Vibrio cholerae, Escherichia coli and Staphylococcus bacteria; The spice extract extracted from alcohol has a strong inhibitory effect on a variety of bacteria. The spice extract can be used as a preservative with wine.
Clove oil contains eugenol and tannins. Studies have found that clove oil has a broad-spectrum antibacterial effect on Staphylococcus aureus, Escherichia coli, yeast, Aspergillus Niger and other foods, and is stable to heat within 100 ℃. Its outstanding feature is its strong antifungal effect.
Allicin
Allicin contained in garlic has a strong inhibitory and killing effect on some pathogenic intestinal bacteria such as Shigella and common food spoilage fungi. This makes it a natural preservative. The antibacterial properties of garlic cloves are very weak, and garlic seedlings and stems and leaves have considerable antibacterial effects. Its antibacterial performance drops a lot at high temperatures, so it is best to use garlic extract to preserve freshness at a lower temperature (85°C). The optimum pH of garlic is about 4, so it is suitable for the preservation of acidic food.
Bacterial natural preservatives
The bacteriostatic substance produced by bacteria is called bacteriocin, which is a complex of polypeptides, sugars and lipids. Dozens of bacteriocins have been found in lactic acid bacteria (including lactic acid bacteria, Pediococcus, Lactobacillus and Leuconostoc) at home and abroad. Among them, nisin, or niisn, is widely used. Nissan is an intramolecular ring formed by 34 amino acid residues and 5 sulfide bridges. It has a strong inhibitory effect on a variety of Gram-positive bacteria, but it is ineffective against Gram-negative bacteria, yeast and mold.
Natural preservative produced by actinomycetes
Natamycin, also called pimaricin, produced by Streptomyces nata, is a polyolefin macrolide compound that can effectively inhibit and kill toadstools, yeasts, filamentous fungi, and is ineffective against bacteria and viruses. . Tylosin is a macrolide compound produced by streptomycin, and its effect is similar to nisin. The polylysin produced by Streptomyces albicans is a polypeptide formed by condensation of lysine, which can inhibit Gram-positive, negative bacteria and yeast, but it is not effective against molds. It has good thermal stability, heating at 100℃ for 100min or 120℃ for 20min can still inhibit microorganisms. Generally, it is combined with glycine, sodium acetate, ethanol, lysozyme and other auxiliary agents to be used in products such as rice, cooking, jelly vegetables, fish cakes and other products. The lysozyme produced by Streptomyces sphaeroides can specifically dissolve Staphylococcus aureus and other food contaminating bacteria, and has a broader lysozyme spectrum than protein lysozyme.
Mold
The antibacterial substance produced by Monascus mainly acts on bacteria, and this antibacterial substance is related to the polyketide pigment produced. Kojic acid produced by the fermentation of Aspergillus oryzae can inhibit certain bacteria and fungi. Salmonella cheese penicillium is inoculated on the surface of dried sausages, which can inhibit the growth of mycotoxin-producing molds.
Related to natural preservatives are acid flavoring agent, food coating agent and stabilizing agent, I believe you will also be interested in them.
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