Seasonal Variation in Phenolic Content and Antioxidant Activity of Glechoma Hederacea L. Harvested from Six Hungarian Populations

Ground ivy (Glechoma hederacea L.) is one of the prosperous plants for the food-industry as natural antioxidant. This fact led us to examine the chemical diversity of six ground ivy populations situated in different natural habitats and to analyse the effect of the harvesting time. Total phenolic content, chlorogenic acid, and rutin content, as well as the antioxidant capacity showed significant differences due to the harvest time. The highest total phenol content (115 mg g–1 GAE) and the strongest antioxidant activity (53.3 mg g–1 AAE) were measured in the population originated from Budapest (GLE 6), harvested in July. The highest chlorogenic acid (357 mg/100 g) and rutin (950 mg/100 g) contents were detected in the July harvested samples from the Soroksár Botanical Garden population (GLE 1). According to our results, the collection time has significant effect on the total phenolic content – first of all on the chlorogenic acid and rutin accumulation levels of ground ivy, while the influence of the habitat seems to be less important

Comprehensive quantitative analysis of fatty-acyl-Coenzyme A species in biological samples by ultra-high performance liquid chromatography–tandem mass spectrometry harmonizing hydrophilic interaction and reversed phase chromatography

Fatty acyl-Coenzyme A species (acyl-CoAs) are key biomarkers in studies focusing on cellular energy metabolism. Existing analytical approaches are unable to simultaneously detect the full range of short-, medium-, and long-chain acyl-CoAs, while chromatographic limitations encountered in the analysis of limited amounts of biological samples are an often overlooked problem. We report the systematic development of a UHPLC–ESI-MS/MS method which incorporates reversed phase (RP) and hydrophilic interaction liquid chromatography (HILIC) separations in series, in an automated mode. The protocol outlined encompasses quantification of acyl-CoAs of varying hydrophobicity from C2 to C20 with recoveries in the range of 90–111 % and limit of detection (LOD) 1–5 fmol, which is substantially lower than previously published methods. We demonstrate that the poor chromatographic performance and signal losses in MS detection, typically observed for phosphorylated organic molecules, can be avoided by the incorporation of a 0.1% phosphoric acid wash step between injections. The methodological approach presented here permits a highly reliable, sensitive and precise analysis of small amounts of tissues and cell samples as demonstrated in mouse liver, human hepatic (HepG2) and skeletal muscle (LHCNM2) cells. The considerable improvements discussed pave the way for acyl-CoAs to be incorporated in routine targeted lipid biomarker profile studies

The effect of ageing temperature on the physicochemical properties, phytochemical profile and α-glucosidase inhibition of Hibiscus sabdariffa (roselle) wine

The effect of temperature (6, 15 and 30 °C) during ageing on the colour, phytochemical composition and bioactivity of roselle wine was investigated over 12 months. At the end of ageing, wines stored at 6 °C had the highest colour density and lowest polymeric anthocyanins. The initial concentration of most of the individual phenolic compounds decreased during ageing, with reduction of monomeric anthocyanins contributing to the formation of anthocyanin-derivatives (pyranoanthocyanins), eight of which were identified tentatively and reported here for the first time in roselle wine. The decrease in individual phenolic compounds did not affect inhibition of α-glucosidase (maltase) activity, which remained relatively low but stable throughout ageing. Diethyl succinate was the only volatile clearly influenced by ageing temperature, with the most pronounced effect at 30 °C (∼256 fold increase). In summary, the final concentrations of anthocyanins and diethyl succinate were the major compounds influenced by ageing temperature

Comparison of sample preparation techniques for multielemental analysis of wine samples by ICP-MS

The aim of this study was the comparison of different sample preparation methods for multielemental ICP-MS analysis of wine samples. All investigated methods were previously published for the same purpose, but the comprehensive comparison was carried out in the frame of this study for the first time. Five wine samples of different residual sugar content (2 dry, 2 sweet and one extra fine quality dessert wine) were used from Hungarian wine districts. Due to the lack of certified reference materials method validation and cross-checking was carried out by using two different types of inductively coupled plasma mass spectrometers (ICP-MS), namely a quadrupole based ICP-MS equipped with a collision cell (ICP-CC-MS) and a high resolution sector field ICP-MS (ICP-SF-MS). The measured elements were Li, Mg, B, Al, Cu, Rb, Sr, Zr, Cd, Ba, Tl, Pb, Bi, U, Cr, Fe, Mn, Co, Ni, Zn, As, Mo and Ga.Sample preparation procedures were based on sample dilution, microwave digestion using nitric acid (in combination with and without evaporation prior to ICP-MS analysis) and a mixture of nitric acid and hydrogen peroxide. The investigation resulted that the optimal digestion method for the above-mentioned purpose is microwave digestion using nitric acid without evaporation. The advantages and disadvantages of the investigated methods are critically discussed

Simultaneous determination of water soluble vitamins in fortified food products

Vitamins form a heterogeneous chemical group having different stability. In foodstuffs some of them might be bound to matrix components. In the case of vitamin supplemented food products, since the vitamins are not strongly embedded in the matrix a general extraction method could be fit for purpose. The aim of this study was the simultaneous determination of the most common water-soluble vitamins, i.e. ascorbic acid (C), riboflavin (B2), niacin (B3), pyridoxine (B6), folic acid (B9) in enriched food products. Sample preparation based on the European Standard (CEN, 2003) was optimised for further LC-MS compatible chromatography. The separation of the vitamins was achieved by reversed-phase liquid chromatography. Detection was carried out with a photodiode array detector at four different wavelengths. The chromatographic method and the sample preparation were successfully applied for vitamin-enriched cereal, instant cacao powder and fruit juice samples

The effect of UVB radiation on the vitamin D2 content of white and cream type button mushrooms (Agaricus bisporus Lange/Imbach) and oyster mushroom (Pleurotus ostreatus (Jacq.) P. Kumm)

Vitamin D2 is essential for the human body and mushrooms are proved to be one of the best sources of it. In our experiment biologically active, pre-harvest white and cream type button mushrooms and oyster mushroom were treated with UVB light in order to increase their vitamin D2 level, by transforming their natural ergosterol content into vitamin D2. UVB lamps (operating on 312 nm) and six time periods of irradiation (15 to 90 min) were used. After three consecutive days of treatments the yield were measured and samples were taken for vitamin D2 analysis. Data showed considerable increase in vitamin D2 levels at every time period in each cultivar