Antioxidants lecithins

Antioxidant. Lecithin is a natural complement to antioxidants for stabilizing animal fats and vegetable oils. Phospholipids thus help to reduce development of rancidity and to prolong product freshness (319). Lecithin functions particularly well as a synergist with antioxidants. 

Animal Feed. In animal feeds (1—3% lecithin) lecithin is an emulsifier wetting and dispersiag agent energy source antioxidant surfactant source of choline, organically combiaed phosphoms and iaositol and Hpotropic agent. It is used ia a milk replacer formula for calves (approximately 10,000 t of lecithin ate used for this purpose) and for veal production, ia mineral feeds, poultry feeds, fish foods, pet foods, and feeds for fur-beating animals (30). 

Food. Lecithin is a widely used nutritional supplement rich ia polyunsaturated fatty acids, phosphatidylcholine, phosphatidylethanolamine, phosphatidjhnositol, and organically combiaed phosphoms, with emulsifying and antioxidant properties (38). 

M C roni nddoodles. Lecithin (0.25—5%) is used as a conditioning ageat and antioxidant, improves machining, counteracts disiategration and syneresis, and improves color retention. 

Edible Oils and Fats. lecithin (0.01—2%) is used as an emulsifier, wetting agent, and antioxidant it extends shelf hfe, especially of animal fats iacreases lubricity (shortening value) improves stabiUty of compouad shortenings and lowers cloud poiat of vegetable oils. 

One excellent UV protector for foods is PABA, a B vitamin. Likewise, many of the same antioxidants we ingest as health supplements—such as vitamin C and a similar chemical, erythorbic acid vitamin E and lecithin, a source of the important nutrients choline and inositol—occur naturally in food. 

Lecithin is also an antioxidant, helping to keep fats from going rancid (but in the process, going rancid itself). 

In addition to phenolic substances, there are other components present in foods which have no antioxidant activity of their own, but which increase that of phenolic antioxidants. They are called synergists, and they should be accounted for in any discussion of antioxidant activity. Polyvalent organic acids, amino acids, phospholipids (lecithin) and various chelating agents belong to this group. Proteins may modify the efficiency of antioxidants as they react with the reaction products of both antioxidants and synergists. 

NASNER A (1985) Die antioxidative Eigenschaften von Lecithin , Feite, Seifen, AnstrichmitteV, 87 (12) 477-81. 

The selection of an appropriate antioxidant depends on factors such as stability, toxicity, efficiency, odor, taste, compatibility with other ingredients, and distribution phenomena between the two phases. Antioxidants that give protection primarily in the aqueous phase include sodium metabisulfite, ascorbic acid, thioglycerol, and cysteine hydrochloride. Oil-soluble antioxidants include lecithin, propyl gal-late, ascorbyl palmitate, and butylated hydroxytoluene. Vitamin E has also been used, but its virtue as a natural antioxidant has been the subject of some controversy. 

Satue-Gracia MT, Heinonen M and Frankel EN. 1997. Anthocyanins as antioxidants on human low-density lipoprotein and lecithin-liposome systems. J Agric Food Chem 45 3362—3367. 

Antioxidant therapy might be promising medication for the treatment of some lung disorders. For example, lecithinized phosphatidylcholine-CuZnSOD suppressed the development of bleomycin-induced pulmonary fibrosis in mice [284] these findings could be of relevance for the treatment of bleomycin-stimulated pulmonary fibrosis in humans. Davis et al. [285] recently demonstrated that the treatment of premature infants with recombinant human CuZnSOD may reduce early pulmonary injury. 

Tocopherols are not as effective as antioxidants as the synthetic antioxidants, e.g. BHA or BHT. The antioxidant effect of tocopherols is increased by mixing them with ascorbyl palmitate, ascorbic acid, lecithin or citric acid. Typical confectionery applications are the use of tocopherols with ascorbyl palmitate or lecithin or citric acid in the fat phase of toffees or caramels. Chewing gum base can be treated with a- and y-tocopherol to extend the shelf life. 

Heinonen, M. et al., Effect of protein on the antioxidant activity of phenolic compounds in a lecithin-liposome oxidation system, J. Agric. Food Chem., 46, 917, 1998. 

One -A-Day Antioxidant Plus Antioxidant vitamins and mineral supplement Soybean oil, beeswax, partially hydrogenalcd vegetable oils Lecithin... 

For phenol 1-37 pM For H2O2 30-130 pM For lecithin 2.0-48.7 mg L"1 Superoxide radical 0.02-2.0 mM <5% Working media ft-hexane for tyrosinase electrode chloroform for catalase electrode chloroform/hexane (50% v/v) containing 1% by volume of methanol for lecithin electrode. Antioxidant capacity of wines was evaluated in terms of polyphenol content, sulfite and ascorbic acid, and compared to superoxide radical scavenging... 

Antioxidants are tested for purity by melting point and TLC on heat-activated silica using solvent systems 1) chloroform, 2) chloroform/methanol, 19/1, 3) chloroform/methanol/acetic acid, 19/1/0.1. Antioxidants are added at 0.1% by weight of dispersed lipid. In a typical test, 50 ml of the lecithin microdispersion... 

Figure 10. Antioxidant evaluation by oxidative polyamide fluorescence from soy lecithin liposomes. Key O, blank , lecithin plus hematin A, lecithin-hematin...

We reported (35) on a fluorescence test of the relative effectiveness of antioxidants in oxidizing soy lecithin liposomes (sonicated microdispersions). 

Antioxidants include ascorbic acid, lecithin, and tocopherol and are added to all food products. Other antioxidants, such as butylated hydroxy anisole (BHA), butylated hydroxy toluene (BHT), and gallates, are permitted for use only in specific concentrations of food products. BHA is permitted for use in many countries, but BHT is not permitted because of possible toxicity, such as tumorigenicity. 

Studies on the antioxidant properties of anthocyanins on human low-density lipoprotein (LDL) and lecithin liposome systems in vitro showed that the inhibition of oxidation increased dose-dependently with antioxidant concentration. The oxidation was catalyzed by copper in the LDL system and the effects of the anthocyanins were explained by several antioxidant mechanisms including hydrogen donation, metal chelation and protein binding [33]. Anthocyanins also prevented the oxidation of ascorbic acid (vitamin C), through chelate formation with the metal ions, and finally by the formation of an ascorbic (copigment)-metal-anthocyanin complex [49]. 

Oxidative stability of 00-3 fatty acids can be increased using free radical scavengers. TBHQ (t-butyUiydroquinone) at a concentration of 0.02% has successfully slowed down the oxidation of menhaden oil for up to 40 days, compared with 3 days for the control group (83). a-Tocopherol and butylated hydroxytoluene (BHT) alone or in combination increased the oxidative stability of EPA and DHA (84). The most notable success in fish oil stabilization has been achieved with ternary antioxidant systems, which contain a- or y-tocopherol concentrates, ascorbic acid (or ascorbyl palmitate), and lecithin (85). 

Commercially, tocopherol is available as a pure all-rac-a-tocopherol, mixed tocopherols having various contents of a-, p-, y-, or 8-tocopherols (diluted in vegetable oil) and synergistic mixtures containing tocopherols, ascorbyl palmitate or other antioxidants, and synergists such as lecithin, citric acid, and carriers. Extraction of tocopherols from natural sources and chemical synthesis of tocopherols are well described by Schuler (100). 

Lecithins as antioxidants. The literature is replete with references to the antioxidant properties of lecithins. For example, Pokomy (102) claimed that the addition of soybean phospholipids reduced the rate of autoxidation of sunflower oil and prolonged the induction period. Hudson and Ghavani (103) published data showing that the addition of 0.3% dipalmitoyl phosphatidylethanolamine (DPE) to refined soybean oil increased the induction time during Rancimat analysis from 8.8 hours to 19.3 hours. Hildebrand et al. (104), and Jung et al. (105), also published data demonstrating the antioxidant properties of various phospholipids and commercial lecithins. 

Refined de-oiled lecithin can also be blended with carriers such as cocoa butter, hard butters, medium-chain triglycerides, or other diluents to obtain products with more functionality and different physical characteristics. Up to 40% phospholipids may be incorporated in these carriers without the use of solvents. These products are usually stabilized against autoxidation by the addition of antioxidants (33). De-oiled lecithin should be packaged as soon as possible to prevent moisture... 

Commercial lecithin products that were sold many decades ago for applications such as chocolate and confectionery products, margarine, bakery goods, pasta products, textiles, insecticides, and paints are still active today because of their emulsifying, wetting, colloidal, antioxidant, and physiological properties. Lecithin s multifunctional properties and its natural status make it an ideal food ingredient. The major applications and functional properties of lecithin products are shown in Table 25 (7). 

Functional Uses of Lecithin in Animal Feeds Lecithins can be employed in animal feeds for their numerous functional properties. These applications result from lecithins emulsifying, wetting, colloidal, antioxidant, and physiological properties. 

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