Modern methods to determine vitamin E in foods and feeds

Abstract

Highly specific and sensitive, the proposed fluorometric method for determining α-tocopherol is robust and fairly fast. Ithas been tested in parallel with a conventional thin layer chromatographic method on foods and feeds. The only necessarycleanup is the usual saponification. The unsaponificable fraction can be extracted with ethyl ether or, preferably, withExtrelut columns. Reagents and their solvents are added to the isooctane solution before each successive reaction and arethen eliminated by partition with water. The α-tocopherol (α-T) derivative always remains in isooctane. The first step isnitrosation and elimination of tocopherols and tocotrienols other than α-isomers. α-T is then oxidized to α-tocored (α-TR)with a mixture of sulfuric acid, ferric chloride, and iodine bromide. Α-TR is then condensed to a new reagent: 4,5-dimethylo-phenylenediamine. The phenazine formed is strongly fluorescent. Iodine and bromine add to the double bonds of α-tocotrienol present and quench the fluorescence of its phenazine.

Evaluation of a derogation application for deep‐frying meat products in oil at a temperature higher than 180°C

“…Earlier-mentioned N-NA levels for heat-treated (unprocessed) pork and poultry in the studies by Tricker et al (1991), Yurchenko and Mölder (2007) and Bara et al (2011) are relatively low. It can also be noted that the nitrite content of the heat-treated pork and poultry was not measured in these studies, making it unclear as to whether or not any nitrite was added to these meat products prior to heat treatment.…”

“…Another study measured 1 µg/kg N-nitrosodimethylamine and 1 µg/kg N-nitrosodiethylamine in cooked poultry (no information on dimensions of heat-treated steel) (Bara et al, 2011). Tricker et al (1991 detected mean values of 0.93 µg/kg N-nitrosodimethylamine, 0.25 µg/kg N-nitrosopiperidine and 0.10 µg/kg N-nitrosopyrrolidine in cooked chicken (no information on dimensions of heat-treated sample).…”