Volatiles Distinguishing the European 'Conference' and the Asian 'Yali' Pears Stored at Different Post-Harvest Temperatures

A total of 124 identical volatile aromatic compounds were identified during storage of the European 'Conference' and the Asian 'Yali' pear cultivars in different temperature conditions. Only 5 volatiles were statistically differentiated in both cultivars by means of successive multinomial logistic regression: 3-methylbutan-1-al, 2-methylpropyl acetate, 2-methoxy-4-vinylphenol, ethanol, and eugenol. Significant statistical data obtained by sequential multinomial logistic regression developed by the principal component analysis (PCA) procedure and distinguishing the different 'Conference' and 'Yali' pears storage regimes were dimensionless in themselves. The PCA components were expressed as linear combinations of selected variables necessary to distinguish the cultivars. The eigenvalues of the first three PCA components differentiated the storage regimes. For each principal components were selected volatiles with a probability higher than 0.4. Combinations created from PCA components were shown using clusters distinguishing the pear storage conditions used. Analytical data from SPME-GC/MS such as concentration (ng kgMINUS SIGN 1) demonstrated multiple and order-of-magnitude differences between the 'Conference' and 'Yali' pears. The 'Yali' cultivar exhibited significantly higher concentrations of eugenol.O

Effect of sample dilution on estimated values of antioxidant capacity by photochemiluminiscence method

This paper describes principles of a proper dilution of samples used for the determination of antioxidant capacity by means of a photochemiluminiscence method using the instrument Photochem (Analytik Jena AG). The authors used the method ACL (Lipid-soluble Antioxidant Capacity), which is one of two methods enabling to measure in this instrument. It was demonstrated that values measured by the photochemiluminiscence method ACL were influenced by the degree of sample dilution. When studying effects of dilution of samples of wine and rutin, it was demonstrated that there is a non-linear correlation between the degree of dilution and measured values of antioxidant capacity. At low molar amount of substance (i.e. at 0.5 and 1.0 nmol), the measured value of rutin inhibition was higher than the same that molar amount of trolox. At higher molar amounts (i.e. 3; 4 and 5 nmol), the inhibition value of trolox was higher. This dependent change can be explained by means of a different effectiveness of antioxidants and a different stability of their products with radicals

Effect of Leaf Area Size on the Main Composition in Grape Must of Three Varieties of Vitis vinifera L. in an Organic Vineyard

The concentrations of sugars and acids are very important for the quality and the stability of wines. In addition, the proportion of the two main acids, i.e., tartaric acid and malic acid, is a significant factor for wine taste and stability. Over a period of three seasons in an organic vineyard, the influence of leaf area on the concentration of total soluble solids (TSS), pH, titratable acidity (TA), the concentration of tartaric acid and malic acid, and their mutual proportions were monitored. Vines of three varieties (‘Rhine Riesling’, ‘Pinot Gris’, ‘Sauvignon Blanc’) were treated using three different treatments (proportion of leaves removed 0%, 40%, and 70%). All varieties exhibited positive correlations between leaf area and TSS. In terms of relationships between TA and leaf area, ‘Sauvignon Blanc’ was the most sensitive variety. The highest differences between the individual variants were found for this variety. The tartaric to malic acid ratio displayed a significant seasonal effect, which was mostly more important than leaf area reduction. The size of the leaf area mainly affected the accumulation of sugars in the grapes, while content and ratio of acids was not affected so significantly. Therefore, leaf area regulation is one of the ways to optimize the composition of grapes in organic vineyards

Comparison of anthocyanins present in grapes of Vitis vinifera L. varieties and interspecific hybrids grown in the Czech Republic

Anthocyanins present in the grapes of nine grapevine (Vitis vinifera L.) varieties and ten interspecific hybrids were compared. Total anthocyanin levels were determined in fresh grapes and the values ranged from 0.50 g kg -1 to 4.99 g kg-1. A total of twenty-two different anthocyanins were identified. Malvidin 3-glucoside was the most abundant anthocyanin, with concentrations ranging from 30 % to 64 % of the totals observed. The ratio of acetylated to coumaroylated malvidin and peonidin derivatives ranged from 0.09 (variety: Regent) to 1.34 (variety: Cerason), depending on the variety. Diglucosylated anthocyanins were not found in particular interspecific hybrids such as the teinturier XIV 26-56, Laurot, Merlan, and Nativa. © 2013 Institute of Chemistry, Slovak Academy of Sciences

Effect of Leaf Area Size on the Main Composition in Grape Must of Three Varieties of <i>Vitis vinifera</i> L. in an Organic Vineyard

The concentrations of sugars and acids are very important for the quality and the stability of wines. In addition, the proportion of the two main acids, i.e., tartaric acid and malic acid, is a significant factor for wine taste and stability. Over a period of three seasons in an organic vineyard, the influence of leaf area on the concentration of total soluble solids (TSS), pH, titratable acidity (TA), the concentration of tartaric acid and malic acid, and their mutual proportions were monitored. Vines of three varieties (‘Rhine Riesling’, ‘Pinot Gris’, ‘Sauvignon Blanc’) were treated using three different treatments (proportion of leaves removed 0%, 40%, and 70%). All varieties exhibited positive correlations between leaf area and TSS. In terms of relationships between TA and leaf area, ‘Sauvignon Blanc’ was the most sensitive variety. The highest differences between the individual variants were found for this variety. The tartaric to malic acid ratio displayed a significant seasonal effect, which was mostly more important than leaf area reduction. The size of the leaf area mainly affected the accumulation of sugars in the grapes, while content and ratio of acids was not affected so significantly. Therefore, leaf area regulation is one of the ways to optimize the composition of grapes in organic vineyards

Vulnerable Road User protection service in connected and cooperative environment

Kooperativní systémy inteligentní dopravy C-ITS (Cooperative Intelligent Transportation Systems) a jejich služby mají obecně pozitivní vliv na bezpečnost na silnicích a efektivitu provozu. V tomto článku je shrnut současný stav služeb zajišťujících zvýšenou ochranu zranitelného účastníka provozu VRU (Vulnerable Road User) a jsou identifikovány nedostatky dosavadního výzkumu v této oblasti. Na tomto základě je v článku navrhnuta architektura pro hybridní komunikaci zranitelného účastníka provozu s ostatními uživateli, architektura samotné služby zvýšené ochrany zranitelného účastníka provozu a vhodné rozšíření standartních C-ITS zpráv, které si vyměňují uživatelé této služby. Tento návrh přesně zapadá do plánu budoucích služeb definovaných Evropskou C-ITS platformou a splňuje požadavky Evropské legislativy.Cooperative Intelligent Transportation Systems (C-ITS) and its services have generally positive impact on the road safety and traffic efficiency. This paper summarizes state of the art on Vulnerable Road User (VRU) safety enhancement services and assess shortcomings of the related work. Based on the assessment the paper proposes: hybrid communication architecture for VRU, VRU protection service architecture and suitable C-ITS message set extensions exchanging between service users. The whole proposal fits into the European C-ITS platform future service road map and fulfills requirements of the European legislation

Procedure to reduce sulphite in wine with anion-exchange resin

The aim of this experiment was to eliminate SO2 ions present in wine using the anion-exchanger resins. To compare the effectiveness, 2 following strongly basic anion-exchange resin were used. When activated, the sodium bicarbonate solution (activation solution I) is used to prevent parallel reduction of sulphites, tartates and malates, so the anion-exchange resins were activated in two-step activation. In the second step, it was immersed into a mixture of malic acid and tartaric acid (1:1). After the application of anex into wine, the content of total SO2 was reduced to 97–201 mg.L−1 (depending on the amount of anex added into the wine sample). According to our expectations, the variants with anion-exchange resin activated only with bicarbonate solution, the tartrates and malates were significantly reduced. If the anion-exchange resin was activated with a two-steps activation, the tartaric acid and malic acid were reduced in the range of ± 0.13 g.L−1. This phenomenon was strongly reflected at the anion-exchanger Aqua Osmotic 02. The changes in antioxidant content were not affected by the type of anion-exchange resin, the method of activation, or an amount of used anion-exchanger. The color parameters of wine, expressed by the L * a * b *, were not significantly affected by the effects of anion-exchange resin use

Comparison of some physico-chemical parameters of kiwiberry (Actinidia arguta) cultivars from a cold climate

The Actinidia genus includes a number of commercial fruit species with a wide range of countries of origin. Some species such as A. arguta or A. kolomikta are characterized by a high level of resistance to frost. The aim of this study was to compare the fruit of selected cultivars of kiwiberry. In the kiwiberry fruit, sucrose was the predominant type of sugar. Citric acid was dominant in all samples; it was most represented in the pulp of kiwiberry seedlings and in the skin of kiwiberry ‘Issai’. Kiwiberry fruits feature a higher ascorbic acid content in the skin in comparison with the commercial A. chinensis cultivars. Antioxidant activity of kiwiberry fruit skin was up to 18 times higher than that of the pulp. In view of the kiwiberry fruit having no hair, it is possible to eat the whole fruit, including the skin containing substances beneficial to health