Effects of polyphenol supplementation to in vitro antioxidant potential of citrus juices

Food preparations containing substances with antioxidant activity have considerably aroused the interest of consumers, which has led to the marketing of a number of dietary supplements such as resveratrol, hesperidin or chlorogenic acid. On the other hand, natural antioxidants present in citrus fruit juices, together with dietary supplements, could contribute to an enhancement of their antioxidant properties and, in turn, alter their physiological impacts. The aim of the study was to evaluate the effect of supplementation of freshly squeezed citrus juices with resveratrol, hesperidin and chlorogenic acid on the in vitro antioxidant potential of the juices. The solutions of juices, selected polyphenols and the mixtures of solutions of juices and solution of polyphenols were analyzed to determine total polyphenol concentration using the Fast Blue method and total antioxidant potential by the ABTS method. As a result three different types of interactions were established: synergistic of chlorogenic acid which additionally increased the antioxidant potential by 35 - 38% over theoretical predictions, additive - after addition of resveratrol, and antagonistic - in the case of hesperidin. While the antioxidant potential was substantially higher in the mixture of mandarin juice with chlorogenic acid, the measured total polyphenol concentration decreased. Also a considerable decrease in the concentration of polyphenols was measured in the mixtures of mandarin and orange juices with resveratrol, all these possibly due to the sensitivity to other substances present in juices of the analytical method applied. A correlation between antioxidant potential of all examined solutions and total polyphenol concentration was found (r2 = 0.8879)

Factors influencing on the Silesian University students’ decisions concerning purchasing of vitamin and mineral food supplements

Prawidłowo skomponowana dieta pokrywa zapotrzebowanie zdrowego, dorosłego człowieka na składniki odżywcze, witaminy oraz składniki mineralne. Obserwuje się jednak stale rosnące spożycie suplementów diety z grupy witamin, składników mineralnych i innych składników pokarmowych. Krajowy rynek suplementów diety zawierających witaminy i składniki mineralne oferuje szeroką gamę produktów zróżnicowanych zarówno pod względem jakościowym jak i ilościowym. Celem niniejszej pracy była ocena czynników, którymi kierują się studenci różnych kierunków Śląskiego Uniwersytetu Medycznego przy zakupie preparatów witaminowo-mineralnych. Badanie ankietowe przeprowadzono w grupie 208 studentów w wieku od 19 do 24 lat spośród których 99,5% zażywało dotychczas preparaty witaminowo-mineralne. Na podstawie uzyskanych wyników stwierdzono, że głównymi czynnikami decydującymi o wyborze i zakupie suplementu diety przez studentów są: skład preparatu, cena oraz wygoda jego stosowania. Internet natomiast okazał się głównym źródłem informacji o omawianych preparatach.Correctly composed diet covers the demands of a healthy adult for nutrients, vitamins and minerals. Nowadays constant increase of vitamin and mineral supplements of diet intake is observed. Customers have a great choice of diet supplements on Polish market. They are diversified under the quality and quantitative accounts. The main aim of this study was to evaluate main factors of Silesian University students’ choice while they are purchasing particular diet supplements. The questionnaire survey was conducted in a group of 208 students at the age of 19 to 24. 99,5% of them admitted that they have supplemented their diets with vitamin and mineral preparations until the moment of the experiment. The results indicate that main factors that influence the students’ decisions on purchasing these preparations are: composition of the supplement, price and convenient dosing regimen. Respondents indicate the internet as a main source of information on the supplements being discussed in the following study