Carotenoids are important pigments found in foods and biological samples. Among carotenoids, β-carotene is the major carotenoid present in vegetable oils. It plays an important role in the thermal stability of the vegetable oil. We established a simple, precise, specific, sensitive, repeatable, and accurate HPTLC method for the analysis of β-carotene in fortified vegetable oils and assessment of its degradation. Analysis was performed on silica gel HPTLC plates with petroleum ether-hexane-acetone 2:3:1 (
) as mobile phase and densitometric detection. The
of β-carotene was 0.91 and regression analysis showed response was a linear function quantification of amount of β-carotene in the range 100–600 ng (
= 0.99991). The limits of detection and quantification were 0.11 and 0.37 ng, respectively. The thermal degradation (1–5 h at 100°C) of β-carotene in fortified sunflower oil was studied. It was observed that this HPTLC method could be used for efficient analysis and monitoring of the degradation of β-carotene in edible oils.
Authors:Enikő Vida, Orsolya Valkó, A. Kelemen, P. Török, B. Deák, T. Miglécz, Sz. Lengyel, and B. Tóthmérész
We studied the early vegetation dynamics in former croplands (sunflower and cereal fields) sown with a low-diversity seed mixture (composed of 2 native grass species) in Egyek-Pusztakócs, Hortobágy National Park, East-Hungary. The percentage cover of vascular plants was recorded in 4 permanent plots per field on 7 restored fields between 2006 and 2009. Ten aboveground biomass samples per field were also collected in June in each year. We addressed two questions: (i) How do seed sowing and annual mowing affect the species richness, biomass and cover of weeds? (ii) How fast does the cover of sown grasses develop after seed sowing? Weedy species were characteristic in the first year after sowing. In the second and third year their cover and species richness decreased. From the second year onwards the cover of perennial grasses increased. Spontaneously immigrating species characteristic to the reference grasslands were also detected with low cover scores. Short-lived weeds were suppressed as their cover and biomass significantly decreased during the study. The amount of litter and sown grass biomass increased progressively. However, perennial weed cover, especially the cover of Cirsium arvense increased substantially. Our results suggest that grassland vegetation can be recovered by sowing low diversity mixtures followed up by yearly mowing. Suppression of perennial weed cover needs more frequent mowing (multiple times a year) or grazing.
Authors:Hellyda K. T. A. Silva, Thiago Chellappa, Fabíola C. Carvalho, Edjane F. B. Silva, Tarcísio A. Nascimento, Antônio S. Araújo, and Valter J. Fernandes Jr.
sunflower, castor, and soybeans from 2007 to 2008 has grown considerably, though two of these are directed to the food sector. In recent years, the cultivation of castor beans was encouraged, especially by displaying socio-economic benefits and the tendency
Authors:Aysel Kantürk Figen, Osman İsmail, and Sabriye Pişkin
characteristics of different types of agricultural material, there are only a few studies on kinetic analysis especially about the devolatilization of sunflower, rice, corn, and wheat stalks based on Coats&Redfern, Horowitz&Metzger, and Arrhenius non
Békési, P. (2002): A napraforgó legfontosabb betegségei és az ellenük alkalmazható védekezés lehetőségei. (The most important diseases of sunflower and potential protection against them.) Gyakorlati Agrofórum