Naslov
Determination of polyphenols and methylxanthines in chocolates produced in Croatia by UV/VIS and HPLC

Autori
Radojčić, Ivana ; Delonga, Karmela ; Carić, Marija ; Kujundžić, Dijana ; Vorkapić-Furača, Jasna

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Annals of Nutrition&Metabolism / Battistini, N. C. ; Rossi, L. ; Sette, S. - Basel : Karger Publishers, 2003

Skup
9th European Nutrition Conference

Mjesto i datum
Rim, Italija, 01.10.2003. - 04.10.2003

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Polyphenols; Methylxanthines; Chocolates; HPLC

Sažetak
The benefits of chocolate have been recognized due to the presence of polyphenols [(-)-epicatechin, (+)-catechin and procyanidins] and methylxanthines (theobromine and caffeine), biologically active compounds. Polyphenols show the antioxidant capabilities higher than some fruit and vegetables and have protection effect against cardiovascular diseases, and possibly cancer. Therefore, the exact nature and amounts of flavonoids in commercially available chocolates should be known. The common methods for estimating their total content are colorimetric measurements, for radical scavenging capabilities the measurement with DPPH, while the identification of individual polyphenols and methylxanthines can be done by high performance liquid chromatography (HPLC). The objective of our study was determination of total amounts of polyphenols and methylxanthines in dark and milk chocolates on the Croatian market by UV/VIS spectrometry and HPLC. The total amounts of polyphenols were obtained by the Folin-Ciocalteu reagent and their range was 2.94-8.81 mg g-1 chocolate, depending on amount of cocoa liquor. The chocolates with a higher content of cocoa liquor showed higher content of total polyphenols and procyanidins. Radical scavenging measurements with DPPH exerted strong dependence on the content of cocoa liquor, too. In all the chocolate samples the estimated content of (-)-epicatechin (0.206-0.524 mg g-1 chocolate) was higher than that of (+)-catechin (0.078-0.216 mg g-1 chocolate). The procyanidins were identified by UV-DAD as well as some other polyphenolic compounds. The predominating compounds in acetone extracts analyzed by HPLC were theobromine (5.12-14.22 mg g-1 chocolate) and caffeine (0.328-1.15 mg g-1 chocolate) making chromatographic separation of other compounds especially difficult.

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

POVEZANOST RADA