Manganese screening of pineapple by total-reflection X-ray fluorescence (TXRF) spectroscopy

Manganese is regarded as an essential trace element for human nutrition and is found in pineapple fruits in elevated concentrations. In this study, the manganese content of pineapple and pineapple juice was analysed by total-reflection X-ray fluorescence (TXRF) spectroscopy. The manganese concentration in whole fruits was highly variable, however, inside the individual fruit there is an increase from the fruit flesh to the skin of the pineapple. Looking at industrially processed pineapple products, purees (n = 12) have the lowest manganese content with a median of 4.9 mg/kg compared with pineapple juices (10.5 mg/kg, n = 17) and concentrates (15.5 mg/kg; n = 48, calculated to 12.8 °Brix). Depending on the concentration of the product, the tolerable daily intake of manganese is nearly reached with only one glass (200 mL) of pineapple juice.Mangan gilt als essenzielles Spurenelement für die menschliche Ernährung, die Ananas enthält hiervon deutliche Mengen. In dieser Studie wurde der Mangangehalt von ganzen Ananas, Säften und Pürees mithilfe der Totalreflektions-Röntgenfluoreszenzspektroskopie (TRFA) untersucht. Der Mangangehalt der Ananas ist sehr variabel, die Konzentration nimmt jedoch vom Fruchtfleisch zur Schale hin zu. Von den industriellen Verarbeitungsprodukten haben die Pürees (n = 12) mit einem Median von 4,9 mg/kg den geringsten Gehalt, verglichen mit dem Saft (10,5 mg/ kg; n = 17) und den Konzentraten (15,5 mg/kg; n = 48, berechnet auf 12,8 °Brix). Abhängig von der Konzentration im Produkt kann die empfohlene tägliche Aufnahme von Mangan mit einem Glas Ananassaft (200 mL) erreicht werden

Influence of processing on quality parameters of strawberries

To determine the effects of different processing steps, such as enzymatic treatment of the mash and pasteurization, on selected quality parameters, strawberries were processed to juices and purees. To identify the processing steps causing the highest losses, samples were taken after each step, and ascorbic acid, total phenols, anthocyanins, and antioxidant capacity were analyzed. To assess the antioxidant capacity, three different methods were applied: the trolox equivalent antioxidant capacity (TEAC), the ferric reducing antioxidant power (FRAP), and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, showing correlation coefficients of 0.889 to 0.948. The antioxidant capacity decreased with processing steps except heat treatment, which partly caused an increase due to the formation of antioxidant active products. The content of ascorbic acid, in comparison to that in the frozen strawberries, decreased significantly during the processing of the fruit to puree by 77%. In the pressed cloudy juices, the loss of ascorbic acid was 37%. The decline of phenolic compounds, measured as total polyphenols and anthocyanins, was smaller (between 30−40%). Pressing and pasteurization were the most critical steps for the decrease of these compounds. The enzymatic treatment of the mash within 90 min supported the release of secondary plant metabolites, while ascorbic acid is reduced up to 20%

Potential wine ageing during transportation

In a global world, wineries have to satisfy the demand of consumers who wish to drink high quality wines from countries all over the world. To fulfill this request wines have to be transported, crossing thereby great distances from the place of production to the consumer country. At the Institute of Enology of Hochschule Geisenheim University examinations with White-, Rosé- and Red-Wines of different origins which had been transported over longer distances within Europe (Portugal, France, Italy to Germany) by trucks were carried out. Shipping of wines was simulated in a climatized cabinet to analyze the influence on wine quality during this way and conditions of transportation. Time and temperature profiles were based on real transport situtations which were recorded during shipping from Germany to Japan using data loggers. White, Rosé and Red wines were transported during 6 to 8 weeks and then were analytically and sensorically compared to those which were stored at a constant temperature of 15 ∘C. Besides the effect of temperature, the movements and vibrations encountered by the wines were also examined. Analytically wines were analyzed for general analytical parameters with Fourier-Transformation-Infrared-Spectroscopie (FTIR), Colour differences (Spectralphotometrie) and free and total sulfuric acid with Flow-Injection-Analysis (FIA). Sensory examinations with a trained panel were performed in difference tests in form of rankings and triangular tests. Summarizing the results from the different tests it could be found that transportation had an influence on the potential ageing of wines depending on the wine matrix. Especially high and varying temperatures during transportations over a longer distance and time had negative influences on wine quality. Also the movement of wine at higher temperatures had showed a negative effect whereas transport at cool temperatures even below 0 ∘C did not influence wine characteristics. Sophisticated, younger white and lighter wines with distinct levels of carbon dioxide showed tendencially clearer analytical and sensorical differences between transported and non-transported samples

Responses on Must and Wine Composition of <i>Vitis vinifera</i> L. cvs. Riesling and Cabernet Sauvignon under a Free Air CO₂ Enrichment (FACE)

Challenges of climate change on the future grape and wine production are widely discussed in science and in the wine industry with the goal to maintain a consistent must and wine quality in the future. Therefore, the effect of elevated CO2 (eCO2)—as one of the relevant greenhouse gases jointly responsible for a changing climate—was investigated concerning the composition of must and wine made of two grapevine cultivars V. vinifera L. cvs. Riesling and Cabernet Sauvignon within the established VineyardFACE (Free-Air Carbon dioxide Enrichment) experiment. Must and wine analysis were conducted in three consecutive years (2014–2016) by analyzing standard must and wine parameters, e.g., total soluble solids (TSS), pH, total acidity (TA), organic acids (e.g., tartaric acid, malic acid, shikimic acid, citric acid, volatile acid and gluconic acid) or total phenolics (TP). Also, for both cultivars CIELab coordinates (L* for lightness, a* as green/red and b* as blue/yellow components) were used to test colour in young white and red wines. Additionally, total anthocyanins and monomeric indices were analyzed for young wines of the red cultivar Cabernet Sauvignon. With marginal differences between CO2 treatments, the composition of must and young wines was not found to be negatively influenced by an eCO2 concentration

Responses on Must and Wine Composition of Vitis vinifera L. cvs. Riesling and Cabernet Sauvignon under a Free Air CO2 Enrichment (FACE)

Challenges of climate change on the future grape and wine production are widely discussed in science and in the wine industry with the goal to maintain a consistent must and wine quality in the future. Therefore, the effect of elevated CO2 (eCO2)&mdash;as one of the relevant greenhouse gases jointly responsible for a changing climate&mdash;was investigated concerning the composition of must and wine made of two grapevine cultivars V. vinifera L. cvs. Riesling and Cabernet Sauvignon within the established VineyardFACE (Free-Air Carbon dioxide Enrichment) experiment. Must and wine analysis were conducted in three consecutive years (2014&ndash;2016) by analyzing standard must and wine parameters, e.g., total soluble solids (TSS), pH, total acidity (TA), organic acids (e.g., tartaric acid, malic acid, shikimic acid, citric acid, volatile acid and gluconic acid) or total phenolics (TP). Also, for both cultivars CIELab coordinates (L* for lightness, a* as green/red and b* as blue/yellow components) were used to test colour in young white and red wines. Additionally, total anthocyanins and monomeric indices were analyzed for young wines of the red cultivar Cabernet Sauvignon. With marginal differences between CO2 treatments, the composition of must and young wines was not found to be negatively influenced by an eCO2 concentration

Effect of Sequential Inoculation with Non-Saccharomyces and Saccharomyces Yeasts on Riesling Wine Chemical Composition

In recent years, studies have reported the positive influence of non-Saccharomyces yeast on wine quality. Many grape varieties under mixed or sequential inoculation show an overall positive effect on aroma enhancement. A potential impact by non-Saccharomyces yeast on volatile and non-volatile compounds should benefit the flavor of Riesling wines. Following this trend, four separate sequential fermentations (using the non-Saccharomyces yeasts Torulaspora delbrueckii, Metschnikowia pulcherrima, Pichia kluyveri, and Lachancea thermotolerans with Saccharomyces cerevisiae) were carried out on Riesling must and compared to a pure culture of S. cerevisiae. Sequential fermentations influenced the final wine aroma. Significant differences were found in esters, acetates, higher alcohols, fatty acids, and low volatile sulfur compounds between the different trials. Other parameters, including the production of non-volatile compounds, showed significant differences. This fermentation process not only allows the modulation of wine aroma but also chemical parameters such as glycerol, ethanol, alcohol, acidity, or fermentation by-products. These potential benefits of wine diversity should be beneficial to the wine industry

Analytical examination of dealcoholized wines

The demand for dealcoholized wine has been steadily increasing in recent years. Moreover, the attention for such products is probably increasing even more. More producers are seeking to participate in the marked to dealcoholized wine. Due to that increasing demand and market awareness the different legal authorities are also discussing the regulation and harmonizing of rules, for those products. However, there is a lack of precise data on how to analytically describe these products on the market. To this end, the present study examined 200 commercial dealcoholized wines and their carbonated variants on the basis of key enological analytical parameters (acidity, density, extract, glycerin, exact alcohol content, etc.). This work aims to help understand the specific characteristics of dealcoholized wines that are currently found on the major wine markets

Grapevine age : impacts on physiological parameters and wine quality

Poste

Impact of grapevine age on vigor and berry development

Oral presentatio