DOI: 10.11118/978-80-7509-996-9-0297

STANOVENÍ CELKOVÉHO OBSAHU OXIDU SIŘIČITÉHO A PODÍLU JEHO VOLNÉ FORMY V CITRONOVÉ ŠŤÁVĚ A OCHUCOVADLECH NA JEJÍ BÁZI / DETERMINATION OF THE TOTAL CONTENT OF SULFUR DIOXIDE AND THE PROPORTION OF ITS FREE FORM IN LEMON JUICE AND FLAVORINGS BASED ON IT

Jan Pospíšil¹, Kateřina Debreczeniová¹

¹ Ústav hygieny a technologie potravin živočišného původu a gastronomie FVHE, VETUNI, Palackého třída 1, 612 42 Brno

This work deals with the comparison of the total content of SO₂ and the amount of its free form, which is responsible for the antibacterial and antioxidant properties of SO₂ in food. The subject of the research was lemon juice available on the Czech market and flavorings based on it. Twenty-two products were divided into 2 groups: SO₂ treated products (n=10) and SO₂ free products (n=12). The analysis was performed spectrophotometrically using analytical sets K-TSULPH and K-FSULPH (Megazyme Ltd., IE). Total content of SO2 in treated products ranged between 37–364 mg.l^-1, while the free form was present in the amount of 20–186 mg.l^-1. In 20% of the samples, the proportion of its free form was very low, even though the total SO₂ content was considerable. Statistically significant difference (p < 0.05) was demonstrated in the total SO₂ content between the treated and non-treated products. The legislative limit of 350 mg.l^-1 was exceeded only in one sample, when the determined value was 364 ± 6 mg.l^-1.

Keywords: sulfites, fruit juices, free sulfites, lemon seasonings, Ellman’s reagent

pages: 297-302, online: 2024