Relationship between the Sensory-Determined Astringency and the Flavanolic Composition of Red Wines

[EN] The relationship between the proanthocyanidin profile and the perceived astringency was assessed in 13 commercial Tempranillo red wines. The concentration and compositional information were obtained by liquid chromatography with diode array detection coupled to electrospray ionization mass spectrometry after acid-catalyzed depolymerization of wine proanthocyanidins in the presence of excess phloroglucinol. Statistical analysis of the results showed significant correlations between sensory and chemical determinations. Astringency was more affected by the subunit composition than by the total concentration or the average degree of polymerization of wine proanthocyanidins. Higher proportions of epicatechin (EC) subunits in extension positions and gallocatechin (GC) subunits in terminal positions were shown to increase astringency. On the contrary, the amount of epigallocatechin (EGC) in both extension and terminal positions was negatively correlated with the perceived astringency

Stability of the Secondary Antioxidant Bis(2,4-di-tert-butylphenyl)pentaerythritol Diphosphite in Food Simulants

To establish the stability of Ultranox 626 (an antioxidant added to plastics) in food simulants under migration conditions, migrations tests have been performed. A method has been developed for the determination of Ultranox 626 in the aqueous food simulants distilled water, 3% (w/v) acetic acid, and 15% (v/v) ethanol and in the fatty food simulants 95% (v/v) ethanol and isooctane. The method uses reversed-phase high-performance liquid chromatography with ultraviolet detection at 230 nm, is fast, and can be run automatically. To determine the stability of Ultranox 626, it was heated in each of the listed food simulants under the conditions stipulated in EU regulations for testing for compliance with migration limits. These experiments showed that this additive had acceptable stability in water, 15% and 95% (v/v) ethanol, and isooctane but that it decomposed completely in 3% (w/v) acetic acid. Migration testing with 3% acetic acid is of no use, since by the end of the testing regime the additive will have undergone substantial or total decomposition, and the level detected will not reflect the true level of migration. The EU Commission should replace 3% acetic acid with 15% ethanol as an appropriate test simulant for the determination of Ultranox 626 in all types of acid- and alcohol-containing foodstuffs. A number of experiments were carried out to develop a suitable method for the determination of Ultranox in fat simulants such as olive oil and HB 307. It appeared not possible, within the scope of this project, to obtain a method suitable to establish the stability of Ultranox 626 in fat simulants. Best results were obtained by freezing out the fat at -80 °C, but recovery was limited to 50%, which was insufficient for the intended purpose. Further experiments are required to establish the stability of Ultranox 626 in fat simulants such as olive oil and HB 307

Organochlorine pesticide residues in Galician (NW Spain) honeys

Organochlorine pesticide residues were analyzed by capillary gas chromatography-electron capture detection (GC-ECD) on 101 Galician (NW Spain) honey samples. Of the 101 honey samples, 13 were free from detectable residues. The pesticides found were HCH (isomers other than lindane) present in 47 samples (trace to 161 μg/kg), lindane in 57 samples (trace to 59 μg/kg), heptachlor in 29 samples (trace to 57 μg/kg) aldrin in 36 samples (1 to 150 μg/kg), dieldrin in 9 samples (trace to 13 μg/kg), endrin in 1 sample (7 μg/kg), op'DDT in 7 samples (1 to 12 μg/kg), pp'DDT in 18 samples (1 to 61 μg/kg) and methoxychlor in 11 samples (19 to 593 μg/kg)