Corn tocopherol content

That tocopherols are apparently nature s choice of antioxidant is demonstrated in Fig. 4, which is similar to a correlation observed by Hove and Harris (1951). Here the total tocopherol content of oils from babasu (1), beechnut (2), carrot (3), castor bean (4), cacao (5, 6), coconut (7, 8), corn (9, 10), cottonseed (11-13), hazelnut (I4, 15), linseed (16), oat germ (17), okra seed (18, 19), olive (20-25), palm (26-28), peanut (29-33), pecan (34, 35), poppyseed (36), rapeseed (37), rice bran (38), safflower (39), sesame (40, 4I), soybean (42-44), sunflower (45), and wheat germ (46-50), as reported by Lange (1950), have been plotted against their total linoleic plus linolenic acid content as reported by Hilditch (1956). The linoleic, plus linolenic acid content of oils from the same species varies, sometimes threefold. It is unfortunate that the content of tocopherol, linoleic acid, and linolenic acid have seldom been determined on the same sample. If Fig. 4 could have been prepared from such data, the correlation would probably be even more dramatic. 

The high biological effect tocopherols are present in an amount of 0,02-0,1%. Arachis oil and corn oil are rich in tocopherols. These components as natural antioxidants influence the oxidation stability of polyunsaturated fatty acids. In course of edible oil production, the tocopherol content also decreases, it can be 30-50%, depending on the parameters of the deodorization. The more colourless and odourless product is produced, the less tocopherol... 

TABLE 17. Effect of Processing on the Tocopherol, Phosphorous (P), Iron (Fe), and FFA content of Corn Germ Oil. ... 

The unsaponifiable matter of soy, corn, canola/rapeseed, sunflower, cottonseed, peanut, and palm ranges from 10-30%, and it is composed of 40% phytosterols and 15% tocopherols (199-202). The temperature, duration, quantity of skimming vapor, and the extent of vacuum used for deodorization are the parameters that greatly influence the quality and quantity of DOD. The low content of tocopherols and sterols in the DOD often requires a concentration step however, if the starting material is soybean, this is not an issue because of the high concentration of these compounds. 

Details of the tocopherol components are shown in Table 5.11 (Muller-Mulot 1976) and of the sterols and sterol esters in Table 5.12 (Popov et al. 1975). Values for other typical vegetable oils, such as soybean and corn, are included for comparison. Both soybean and corn oils have higher levels of y-and 8-tocopherol than sunflower oil. There is some difference between the sterol contents of the three oils, but the sterol ester content of com oil is much higher than in either sunflower or soybean oils. 

Based upon the conventional wisdom of the time, not much attention was directed toward the types of fat in the diet, except as they represented a source of tocopherol. Accordingly, although the relationship betw een polyunsaturated fatty acids and tocopherol should have been apparent to us from earlier clues in the literature (Filer et al., 1946) it was not until April 1956 that an attempt was made to increase the linoleic acid content of the diet by substituting stripped corn oil for the stripped lard which had been used as the source of fat in the human experiment. Obviously, any choice of how much tocopherol should be left in the basal diet had to be a... 

The cod liver oil proved to be the critical component of the diet. Substitution by com oil made the diet nontoxic, and crude linoleic acid was approximately as effective. The eclamptic disease could be prevented by treating the animals with a-tocopherol or lettuce before the toxic diet was given, or by adding these materials to the eclamptogenic diet. Apart from a possible toxic effect of the vitamin D, it is also possible that the oil itself has a toxic effect. It is known that highly unsaturated acids are present which do not have the activity of the essential unsaturated fatty acids, because they have cis-trans and trans-trans configurations instead of the active cis-ds form. Even deficiency of the essential unsaturated fatty acids may be promoted. The crude linoleic acid, which was not quite as active as corn oil, may contain about 50% of the inactive cis-trans configura-tion(s). The vitamin E content of the com oil is probably important also. 

Frankel et al. (1996a) also observed that camosol and camosic acid were significantly more active antioxidants in oil-in-water emulsions buffered at pH 4 or 5 than at pH 7. Hopia et al. (1996) reported that camosic acid was a better antioxidant than camosol in methyl linoleate, but that the reverse was tme in linoleic acid. In methyl linoleate or linoleic acid, camosic acid and camosol were more active than a-tocopherol. However, a-tocopherol was more active in bulk corn oil triacylglycerols, followed by camosic acid and camosol. The oxidative stability of rapeseed oil treated with rosemary extracts correlated well with the content of camosic acid, but not with content of camosol (Trojakova et al, 2001). In all emulsified systems, a-tocopherol exhibited more antioxidant activity than camosol or camosic acid (Hopia et al., 1996). In bulk com oil, the addition of camosol to a-tocopherol had a negative impact on the antioxidant activity of a-tocopherol, whereas camosic acid enhanced a-tocopherol activity (Hopia et al, 1996). Both camosic acid and camosol disappeared from the test system more quickly than a-tocopherol (Hopia et al, 1996). 

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