Vitamin E má u člověka jen relativně mírné projevy hypovitaminózy, které navíc nejsou, ve většině případů, způsobeny nedostatečným obsahem tokoferolů ve stravě. Pozornosti výživové politiky tak pravděpodobně uniká fakt, že skutečný příjem vitaminu E je u většiny populace (celosvětově) nedostatečný. Tento přehled shrnuje aktuální informace o doporučeném a reálnem příjmu vitaminu E a o rizicích a případných benefitech spojených s jeho nedostatečným či zvýšeným příjmem.
Vitamin E has only relatively mild manifestations of hypovitaminosis in humans, which, moreover, are not, in most cases, caused by insufficient content of tocopherols in the diet. Thus, the fact that the actual intake of vitamin E is (worldwide) insufficient in the majority of the population is likely to escape the attention of nutrition policy. This review summarizes current information on the recommended and actual intake of vitamin E and on the risks and possible benefits associated with insufficient or increased intake.
Vitamin E was described in 1922 and its basic mecha-nism of action was elucidated in 1931. However, some new compounds with vitamin E activity have beendiscovered, and some unknown mechanisms of action of this vitamin invivohave been described in a research con-ducted in the last 20 years. Therefore, the present review provides a comprehensive, current view of vitamin E.
BACKGROUND: Cholesterol is susceptible to oxidation and the formation of oxysterols, which could have a negative health effect. The formation and distribution of oxysterols was investigated in meatloaves prepared under different baking regimes with an increased temperature or prolonged time. The effect of frozen storage and marjoram addition on the level of oxysterols was also investigated. RESULTS: The effect of baking regime on the content and distribution of oxysterols was determined. Temperature was the most important factor affecting 7-ketocholesterol formation in baked meatloaf. Its content was significantly higher after baking at 250 °C compared to at 180 °C. The content of 7-ketocholesterol increased from the centre (87 μg kg-1 ) to the surface (122 μg kg-1 ) of baked meatloaves prepared under standard conditions. The level of α-tocopherol and its distribution was also affected by the baking regime. A higher level of 7-ketocholesterol was found in baked meatloaves after their frozen storage. The addition of marjoram did not change this level. CONCLUSION: Inadequate culinary conditions used for preparation of baked meat can contribute to an increased oxysterol intake in the diet. Frozen storage did not stop oxysterol formation. The inhibition effect of marjoram on sterols oxidation was not confirmed. © 2017 Society of Chemical Industry.
