Interactions between different antioxidants

　　Some compounds have weaker activity in the pure state and show stronger antioxidant effect in the mixed state. We believe that there is a positive synergy between the components, usually referred to as synergy. Synergy is a common phenomenon among antioxidants. The most typical examples are VC and VE. In 1962, Tappel took the lead in conducting research on the synergy between VE and VC, and put forward the view that VC regenerates VE, and this conclusion was subsequently confirmed by Paker and NiKi.

　　Because the process of synergistic anti-oxidation is relatively complicated, at present people do not fully understand its mechanism. Summarizing the existing research work, there are three main ways of synergistic anti-oxidation:

　　1 Regenerative antioxidant

　　Some antioxidants, such as VC, coenzyme Q can exchange electrons with high-efficiency antioxidants (mainly VE) in addition to acting directly on the oxidation process itself, so that VE maintains normal levels and continuously exerts antioxidant effects. For example, VE and VC have been produced by Jianming in the experiments of inhibiting the lipid peroxidation of soybean phospholipid liposomes, fish oil, linoleic acid or methyl linoleate in homogeneous systems. It was found that the concentration of VE in the initial stage of the reaction was basically No change, but the concentration of VC has decreased. After VC is completely consumed, the concentration of VE begins to decrease. From this, people speculate that VC can reduce VE radicals to VE, thereby increasing the effective concentration of VE in the solution and enhancing the antioxidant capacity; at the same time, VC can also decompose the hydroperoxide of lipid compounds into non-radical products, so Shows synergy.

　　In addition, He Dong et al. used front-line molecular orbit theory to explain the above phenomenon theoretically. The front-line reaction theory points out that it is important for the stability of the reaction system and the formation of new chemical bonds that the ****occupied orbits (HOMO)--****** empty orbits (LUMO) interoperate. Produced by Jianming. The HOMO orbit of VC is composed of Pz orbitals of carbon and oxygen, and the LUMO orbit of VC radicals is also composed of Pz orbits, and the energy level difference between the two is small, so VE radicals may react with VC to regenerate.

　　Palozza and Krinsky observed that β-carotene and VC are more effective than single ingredients in preventing cancer and inhibiting early tumors. Li Zhaolong and others found that β-carotene can effectively inhibit the peroxidation of linoleic acid in a homogeneous organic solution, and when used in combination with VE, it has a significant antioxidant synergy and mutual protection. They attribute this to β -Retinol, the oxidation product of carotene, and β-carotene-degrading aldehyde (RCHO) can reduce VE radicals and regenerate them.

　　It is also reported that TP (tea polyphenols) has a protective effect on VE and VC, TP can protect VE, and can completely inhibit the consumption of VE. Wu Ruirong's research confirmed that TP can promote the storage of VC in human body, the reason is that TP regenerates VC.

　　2 Remove oxygen

　　In vegetable oil and lard, there is a synergistic antioxidant effect between carotenoids and VC. Carotenoids in oils usually have the following reactions:

　　VC has strong reducibility and can react with the oxygen in the oil to reduce the oxygen concentration. When carotenoid is combined with VC, the reaction (2) is inhibited due to the action of VC, the rate of formation of Car-OO· is much less than that of Car·, that is, the concentration of peroxide radicals in the system is effectively reduced, so the performance Antioxidant synergy.

　　3 Chelated metal ion

　　In 1936, Olcott and Mattill found that phenolic antioxidants and acidic substances (such as citric acid, phosphoric acid, etc.) have a very significant antioxidant effect when they are used together. They believe that these acidic substances can chelate trace metal ions and inhibit metals. Catalytic decomposition of peroxides by ions, thus showing a synergistic effect of anti-oxidation.

　　In addition to the above reasons, the synergy may also be caused by the mutual protection between antioxidants. For example, the presence of nucleic acids can form hydrogen bonds with VE to protect VC from other oxidative damage, thus showing synergy. Produced by Jianming.

　　At the same time, Ruan Jianjun (2012) studied the effect of different antioxidants on the oxidation stability of rice bran crude oil. The test uses the acid value (AV), peroxide value ((POV) and malondialdehyde (MDA) content as evaluation indicators. The ethoxyquinoline, tert-butyl hydroxyanisole (BHA), di-tert-butyl hydroxytoluene ((BHT) Three antioxidants are added to the oil in the form of different monomers or combinations to study their effect on the antioxidant properties of rice bran oil. The results show that the effect of composite antioxidants is better than single antioxidants. Rice bran Oil has higher oxidation resistance than general vegetable oils. A large number of studies have shown that when different antioxidants are used in combination, their antioxidant effect is often superior to a single antioxidant. Ma Tao et al. studied accelerated oxidation at (63±1)℃ , Taking peroxide value ((POV) as evaluation index, the influence of TBHQ, BHT, PG, citric acid and compound antioxidants on the antioxidant performance of rice bran oil. The results show that the antioxidant effect of compound oxidants is better than single antioxidants , Citric acid has a synergistic effect on antioxidants. Chen Zhenlin and others studied the effect of different combinations of antioxidants TBHQ, BHA, VC palmitate on the storage stability of rice bran oil, and found that different combinations of antioxidants can improve the storage stability of rice bran oil The stability of rice bran oil added with 0.015% VC palmitate + 0.015% TBHQ + 0.015% BHA can reach 30-33 days, which is 1.43-1.83 times the stability of the control sample.

　　4 What are the antioxidant solutions?

　　In 1968, Jianming discovered the important role of free radical chelating agents in the antioxidant system, and developed antioxidants with dual effects.

　　Then Jianming began to study the synergistic effect between different antioxidants, developed a highly effective compound antioxidant, and creatively carried out scientifically effective ingredients such as EQ, BHA, BHT, metal chelating agents and organic acids***** *Mixed ratio, obtained scientific and efficient compound antioxidant Xianling? and Baoxian? series, so as to efficiently and stably guarantee the quality of oil.