Tea polyphenols are extracted from tea (Camelliasinensis L.) as raw materials, and become the main polyphenolic compound food additives with catechins, also known as Vitamin Phenols. Catechins are mainly: epigallocatechin gallate (EGCG), epigallocatechin (EGC), epigallocatechin gallate (ECG), epicatechin (EC), catechin (C).

Not all teas have the same amount of tea polyphenols. The deeper the tea is fermented, the more the tea polyphenols are converted into other substances, and the tea polyphenol content will decrease accordingly. Green tea is unfermented, the tea polyphenol content is quite rich, some data show that the green tea in the tea polyphenol content than the same quality of black tea is higher than 144%, than the same quality of oolong tea is higher than about 59%.

In addition to the type, the quality of the tea will also affect the content of tea polyphenols. For example, when making tea, the more tender the leaves, the better the quality. This is because young leaves grow at the top, closest to sunlight, and are able to fully photosynthesize, which will synthesize more phenolic substances.

National standard: GB 1886.211-2016 National standard for food safety Food additives Tea polyphenols (also known as Vitaminol)

Characteristics and functions of tea polyphenols

Characteristics of tea polyphenols:

Pale yellow to single tea-colored or tea-brown powder or paste; tea flavor, slightly astringent; easily soluble in water, ethanol, methanol, ethyl acetate, acetone and other solvents, slightly soluble in oils and fats, insoluble in chloroform; hygroscopicity; strong stability, in the PH value of 4-8, 25 ℃ or so of the environment, within 1.5 hours can be stable, in the presence of trivalent iron ions are easy to decompose.

Antioxidant properties:

Tea polyphenols have strong antioxidant properties, its antioxidant capacity is 4-6 times that of BHT, BHA, 6-7 times that of vitamin E, 5-10 times that of vitamin C. And the dosage is small, 0.01%-0.03% can be effective, and there is no potential toxic side effects.

The role of tea polyphenols:

Anti-aging: tea polyphenols can be extremely strong scavenging of harmful free radicals, blocking the lipid peroxidation process, can inhibit the skin mitochondria lipoxygenase and lipid peroxidation, thus having an anti-aging effect. Studies have shown that 1 mg of tea polyphenols scavenging harmful excess free radicals in the human organism is equivalent to 9 micrograms of superoxide dismutase (SOD), much higher than other similar substances; tea polyphenols antioxidant properties than vitamin E is obviously 18 times stronger than vitamin E, and vitamin C, E has a synergistic effect.

Reduce blood lipids: tea polyphenols in the catechin ECG and EGC and its oxidation products such as theaflavin, can inhibit smooth muscle cell proliferation after the formation of atherosclerotic plaques, reduce the viscosity of blood clotting leading to enhanced fibrinogen. Thus inhibiting atherosclerosis.

Relieve allergies: tea polyphenols can strongly inhibit the release of histamine, experiments have proved that tea polyphenols anti-anaphylaxis and anti-allergic skin reactions than the current commonly used anti-allergy drugs inhibit the effect of 2 to 10 times stronger.

Detoxification: Tea polyphenol has a strong adsorption effect on heavy metals, can form complexes with heavy metals and produce precipitation, which is conducive to reducing the toxic effects of heavy metals on the human body. In addition, tea polyphenols also have the effect of improving liver function and diuresis, thus alkaloid poisoning has a better anti-detoxification effect.

Digestion: Caffeine in tea polyphenols can improve the secretion of gastric juice, which can help digestion and enhance the ability to decompose fat. This is the reason why the so-called “long food makes people thin”.

Radiation: Tea polyphenols and their oxidized products have excellent anti-radiation function, which can absorb radioactive substances and prevent them from spreading in the human body, known as the natural ultraviolet filter.

Dental protection: Tea polyphenols can kill lactobacilli and other caries bacteria present in the teeth, with the effect of inhibiting glucose polymerase activity, effectively interrupting the process of caries formation. Protein food remaining in the teeth becomes a substrate for the proliferation of decaying bacteria, and tea polyphenols can kill such bacteria.

Face: Tea polyphenol is a water-soluble substance, wash your face with it can remove facial grease, astringent pores, with disinfection, sterilization, anti-skin aging, reduce ultraviolet radiation in the sun on the skin damage and other effects.

Application of Tea Polyphenol

1. Application of antioxidant in fats and oils

Animal fats and oils do not contain natural antioxidants, they are very easy to oxidize and deteriorate automatically, and the PV value reached 100meq/kq after only 3d exposure in room temperature air. vegetable fats and oils contain some natural antioxidants, but they will be preserved for a long time at room temperature due to auto-oxidation and rancidity. The rancidity and deterioration of fats and oils occurs due to the auto-oxidation reaction of unsaturated fatty acid glycerolipids in fats and oils with oxygen in the air.

The antioxidant activity of tea polyphenols was first used in fats and oil-containing foods. The phenolic hydroxyl group on the benzene ring of catechins has hydrogen-donating activity, which makes its reducing ability strong and makes it an ideal natural antioxidant for fats and oils. The antioxidant mechanism of tea polyphenols is that the active phenolic hydroxyl group acts as a hydrogen donor and combines with free radicals in fatty acids to interrupt the chain reaction of fatty acid oxidation, thus inhibiting the formation of hydroperoxides.

2. Application in meat preservation

In meat processing, you can soak all kinds of meat products in 0.05%-0.2% tea polyphenol aqueous solution for 5-10min, or sprayed on the surface of all kinds of meat products for drying until the meat surface can not be seen droplets until the surface of the meat proteins and tea polyphenol to form a layer of impermeable hard film, which can play a role in preventing the rancidity of meat products, inhibit the generation of bacteria to prevent the effect of corruption and spoilage.

3. For deep-fried noodle products or deep-fried meat products

Fried food in the frying process, vegetable oil in the frying 3h, the peroxide value exceeds the standard of 42.8%, so that the fried food color dark, black, fried instant noodles containing oil in 23% or so, in storage with the oxidation of fats and oils rancidity gradually deepen the role of the products of the aroma, the flavor has been seriously affected by the quality is declining, due to the tea polyphenol is a “carryability As tea polyphenol is a “portable” antioxidant, the antioxidant effect on fried food is better, so adding tea polyphenol in the frying process can slow down the oxidative rancidity phenomenon and improve the shelf life of food.

4. Application in aquatic products

In the production of dry fish products, with tea polyphenols containing 300-500mg / L of water (or seawater) impregnation of aquatic products, can prevent dry fish due to “oil burning” caused by yellowing and lipid oxidation, while spraying the surface of the fish body instead of impregnation treatment, the same effect can also be obtained.

5. Application in jam preservation

Tea polyphenols have antibacterial effect, can better inhibit the damage caused by harmful microorganisms on the fruit and lead to pathological water loss; tea polyphenols have high efficiency antioxidant effect, can slow down the oxidative damage of fruits and vegetables, regulate the activity of polyphenol oxidase, activation of the defense system of fruits and vegetables; at the same time, tea polyphenol molecules contain a number of active phenolic hydroxyl group, can be the molecular hydrogen is provided to the fruits and vegetables directly to the vitamin C, so that it maintains the reduced state, reduce the loss of vitamin C. At the same time, tea polyphenols contain several active phenolic hydroxyl groups, which can provide hydrogen directly to vitamin C in fruits and vegetables to keep it in a reduced state.

Tea polyphenols on different fruit and vegetable preservation mechanism is not the same, different objects require different amounts and conditions of use, to be further studied.

6. Application in functional foods

Tea polyphenols, as the most abundant and widely researched functional components in tea, have unlimited potential in the development of functional foods.

Tea polyphenols have a low redox potential, multiple adjacent phenolic hydroxyl groups can provide hydrogen to interrupt or terminate the chain reaction of free radicals, and their unique chemical structure determines that they have a strong scavenging ability of free radicals; tea polyphenols can activate the scavenging system of free radicals, and can inhibit the production of free radicals by inhibiting oxidative enzymes and complexing transition metal ions that induce oxidation. As a natural free radical scavenger, tea polyphenols are beneficial to human health.

Foreign experience shows that our development of tea polyphenol-related health food is still in its infancy, and at present the country has not been able to take full advantage of our rich tea polyphenol resources to accelerate the development of tea polyphenol health food market. The final recognition of tea polyphenol health food by consumers also requires proper publicity and guidance.

7. Others

Based on the strong reducing properties of tea polyphenols, tea polyphenols can prevent natural pigments such as chlorophyll, carotene, safflower yellow, vitamin B and cochineal from fading due to photo-oxidation, and as a color-preserving agent, it can keep the pigment color bright and stable.