Eva Vítová

Identification of volatile aroma compounds in processed cheese analogues based on different types of fat

The simple and rapid solid-phase micro-extraction method using gas chromatography was used for the identification and quantification of volatile aroma compounds in various types of processed cheese analogues produced from different types of fat (butter, butter oil, coconut oil, palm oil, and sunflower oil). In total, 31 organic compounds belonging to five chemical groups were identified, with the alcohols and fatty acids quantitatively predominant. The contents of the aroma compounds (the so-called aroma profiles) of the analogues and corresponding fats used as raw materials were compared. Significant differences (p < 0.05) were found between samples. The highest total content of aroma compounds was found in coconut oil analogue ((547.30 ± 9.82) mg kg−1), the lowest in palm oil analogue ((372.01 ± 16.16) mg kg−1). The concentrations of aroma compounds in fats were substantially lower (p < 0.05) than in analogues. Hence, the largest number of aroma analogues came from Edam cheese used for production as a protein source.

Comparison of selected aroma compounds in cultivars of sea buckthorn (Hippophae rhamnoides L.)

Thirteen cultivars of sea buckthorn (Hippophae rhamnoides L.) berries: Aromat, Botanicky, Buchlovicky, Hergo, Krasavica, Leicora, Ljubitelna, Pavlovsky, Peterbursky, Sluničko, Trofinovsky, Vitaminnaja and Velkoosecky, were tested for the content of volatile aroma compounds using gas chromatography with the solid phase microextraction method during two consequent years (2012–2013). In total, 69 volatile compounds were identified: 26 alcohols, 12 aldehydes, 11 ketones, 9 acids and 11 esters. Based on principal component analysis, 18 most relevant compounds, best representing the variability of the whole system and suitable for the discrimination of the samples, were selected from all compounds identified. These compounds were then compared using the analysis of variance to confirm differences between the samples. Significant (p < 0.05) differences were found in the varieties in both years, Krasavica and Sluničko cultivars were found to be quite different from other varieties, being rich in the compounds identified and containing most of the selected compounds. Variability within the cultivars (between picking years) was low or not significant.

Multi-experimental characterization of selected medical plants growing in the Czech Republic

Complex analysis of the impact of post-production conditions on antioxidant status, content of selected polyphenols, color, and concentration of selected metals was evaluated in the group of ten most popular medical plants conventionally produced in the Czech Republic. Ultraviolet visible near infrared spectroscopy (UV–VIS–NIR), electron paramagnetic resonance (EPR), high-performance liquid chromatography (HPLC), and inductively coupled plasma optical emission spectrometry (ICP-OES) were employed for these purposes. The entire data set of the obtained experimental characteristics was processed by multivariate statistical methods to assess the influence of the way of processing on sample properties. On the basis of 11 characteristics identified by the analysis of variance (ANOVA) as the most significantly different, successful differentiation of medical plant samples was achieved according to post-harvest treatment, families, and individual medical plant species by means of canonical discrimination method, reaching 100, 89.5, and 100% correctness, respectively. The importance of the sample processing on their properties and on the concentration of target naturally containing compounds with health-promoting and antioxidant properties was thus proved unambiguously.