Vitamin E

Abstract

There is a growing body of evidence to suggest that the dietary intakes of vitamin E are insufficient to protect against the long‐term health risks associated with oxidative stress. Traditional plant breeding and food processing technologies have not concerned themselves with maximising the levels of the tocopherols in the diet, and supplementation is necessary both for nutritive reasons and for the protection of fat‐rich foods against oxidative rancidity. The paper reviews the potential for improving the tocopherol levels in the diet, particularly α‐tocopherol. Genetic technologies have already demonstrated the potential to enhance tocopherol levels by up‐regulation of the final steps in the biosynthetic pathway. Other strategies for the enhancement of the vitamin E content of plant foods are considered both from the perspective of improved bioavailability and the levels in processed foods. Finally some priorities for future research in the field are described. © 2000 Society of Chemical Industry

Effect of storage time on physicochemical and textural properties of sausages covered with oxidized banana starch film with and without betalains

“…Researchers still do not know how exactly these compounds protect the body. Current thinking is that they act as antioxidants that neutralize free radicals, elements that can unleash different pathologies in the body (Bramley et al, 2000;Ferruzzi & Blakeslee, 2007). Betalains are plant compounds often used in the food industry as coloring for fruit juice, but they have not been fully exploited on the industrial level (DelgadoVargas, Jiménez, & Paredes-López, 2000).…”

Genetic Analysis of High .ALPHA.-tocopherol Content in Soybean Seeds

“…Although four isoforms are absorbed equally in human intestines, in human liver, α-tocopherol is specifically recognized and absorbed by a hepatic tocopherol transfer protein (known as α-TTP), while in human blood plasma, α-tocopherol shows the highest retention among the four tocopherols. As a consequence, α-tocopherol displays the highest vitamin E activity whereas the β-, γ-, and δ-tocopherol activity are 40%, 10%, 1-2% respectively, of the vitamin E activity of α-tocopherol (Bramley et al 2000, Schneider 2005. Generally, soybean oil shows a relatively higher total tocopherol content than that of other oil crops such as safflower and sunflower.…”

“…However, in soybean, γ-tocopherol is the most abundant (about 70% of the total tocopherol content); while in safflower and sunflower, α-tocopherol predominates (about 80% of the total tocopherol content). Therefore, the vitamin E activity in soybean is actually lower than that of safflower or sunflower (Bramley et al 2000). Thus, some of the breeding objectives of soybean include the improvement of the nutritional value by increasing the α-tocopherol content and enhancing the vitamin E activity in seeds.…”

Variabilité des teneurs et compositions des composés mineurs dans l’huile de tournesol au cours du développement du capitule

“…Dans les graines au contraire, on trouve principalement les formes c et d. L'activité MPBQméthyl transférase, à l'origine de la voie du c-tocophérol, ainsi que l'activité c-méthyl transférase, produisant les formes b ou a, jouent un rôle prépondérant sur la composition en tocophérols, mais pas sur la teneur totale [19,20], celle-ci semble plutôt dépendre de la synthèse des deux sous-parties de la molécule : HGA et phytyl-DP [15]. Le rôle des tocophérols est capital dans les tissus photosynthétiques, où, par leur activité anti-oxydante, ils peuvent bloquer la propagation de la péroxydation des lipides à l'intérieur de la membrane, en particulier lors de stress hydriques, où les tocophérols contribuent à la photoprotection des chloroplastes [19,21,22]. Une des principales fonctions des tocophérols de la graine serait d'assurer sa viabilité en préservant de l'oxydation les lipides de réserve [23] ; ainsi, pendant le stockage des graines, la teneur des différents tocophérols diminue progressivement [24,25].…”