Palm 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. 

PLE extraction with hexane (80 °C, 1500 psi, one extraction cycle of 10 min) was used to successfully extract tocols from palm-pressed fiber (Sanagi et ah, 2005). Contents and standard deviations of a-tocopherol and a-trienol, and y- and 5-tocotrienols were comparable to those from Soxhlet extraction extraction time with the PLE method was reduced to only 25 min and solvent usage to 45 ml, whereas those with Soxhlet extraction were 8 h and 200 ml. Hexane under PLE conditions has also been used to extract tocols from lyophilized nuts (Sivakumar et ah, 2005) and grape seeds (Freitas et ah, 2008), and always gave higher yields than Soxhlet extraction. 

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. 

Palm oil (also its fraction, palmolein) has good frying stability because of its high contents of gamma- and delta-tocotrienols, aside from the corresponding tocopherols. Tocotrienols contain three unsaturated double bonds as compared with the... 

The content of tocopherol, a natural antioxidant in canola, is comparable to those of peanut and palm oil. This is an important factor for oils with high linolenic acid content, which can reduce the shelf-life of the product, while the namral antioxidant, if present, can prevent oxidation during storage and processing. 

Palm oil is an exception among oil crops, because more than 85% of its vitamin E content consists of y-tocotrienol, a-tocotrienol and a-tocopherol (Tan, 1989). 

Other tocotrienols (i.e., 3-, 8-) are also present (Syvaoja et al., 1986 Ong and Choo, 1997). Total vitamin E content in crude palm oil is between 600-1200 pg/g, while contents in palm oil fractions may be significantly smaller. Palm kernel oil has only <100 pg/g vitamers (Eitenmiller, 1997 Ong and Choo, 1997). Tocotrienols and tocopherols are concentrated up to eightfold in the palm fatty acid distillate compared with the crude palm oil, which enables extraction of vitamin E compounds from this by-product. 

Table 3.13 Vitamin E (total tocopherols and tocotrienols) content in palm oil products...

Abdul Gapor, M.T., Berger, K.G., Hashimoto, T., Tanabe, K., Mamuro, H. and Yamoka, M. (1981) Effects of processing on the content and composition of tocopherols and tocotrienols in palm... 

An excellent example of the implementation of SCFF to obtain palmitic acid from a plant source is the work of Brunner and Machado [7,72]. They conducted a detailed analysis on the fractionation of fatty acids from palm fatty acid distillates (99 % FFA (mainly palmitic, oleic and linoleic acid), 0.9 % squalene and 0.1 tocopherol) starting with a phase equilibrium analysis through to pilot plant studies and experimental verification of the separation. They postulated, from the phase equilibrium studies, that squalene and palmitie acid would be preferentially extracted and verified their postulation experimentally. They also considered a pseudo-binary mixture separation where palmitic acid is to be separated from oleic and linoleic acid and showed, using separation factors that this is possible. On pilot plant scale they showed that such a separation is feasible and balanced yield and extraet quality. At their optimum conditions (373 K, 29 MPa, extract to raffinate ratio of 1.2) they obtained an extract where the palmitic acid content was enriched from 52.5 % in the feed to 74.4 % in the extract and the oleic and linoleic acid content enriched from 46.3 % in the feed to 59.0 % in the raffinate. Squalene was also enriched in the extraet Irom 0.6 % in the feed to 1.2 % in the... 

The fate of endogenous antioxidants in vegetable oils, especially tocopherols, due to microwave heating has also been studied. In com and soybean oils, 90% of the original tocopherol level was retained after 8-10 min of microwave heating, however, in olive, palm and flaxseed oils the content of tocopherols was decreased substantially. When soybean oil was heated for 12 min, 40% of the total tocopherols was lost, but microwave treatment for 6 min retained 90% of their original amounts (Yoshida et al, 1990 1995). 

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