scholarly journals Preliminary study on the influence of UV-C irradiation on microorganism viability and polyphenol compounds content during winemaking of ‘Regent’ red grape cultivar

2017 ◽  
Vol 19 (2) ◽  
pp. 130-137 ◽  
Author(s):  
Kamila Mijowska ◽  
Krzysztof Cendrowski ◽  
Bartłomiej Grygorcewicz ◽  
Jan Oszmiański ◽  
Paweł Nawrotek ◽  
...  

Abstract In this study, UV-C light was tested as an alternative method to inactivate microorganisms in the must of ‘Regent’ red grape cultivar. The control sample containing the microorganism diluted in a physiological NaCl solution was prepared to take into consideration different conditions of liquids, such as turbidity and colour. Additionally, the changes in the composition of polyphenol compounds in the ‘Regent’ must after UV-C exposure were evaluated. The viability of yeasts (Saccharomyces cerevisiae) and bacteria (Oenococcus oeni) significantly decreased with time; however, the highest decline was noted after the first hour of exposure. The polyphenol compound content was significantly lower after UV-C treatment and this was mainly the result of anthocyanin decomposition. The total content of flavan-3-ols and hydroxycinnamic acids and derivatives increased after irradiation.

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 850
Author(s):  
Karolina Nowosad ◽  
Monika Sujka ◽  
Urszula Pankiewicz ◽  
Damijan Miklavčič ◽  
Marta Arczewska

The aim of the study was to investigate the influence of a pulsed electric field (PEF) on the level of iron ion accumulation in Saccharomyces cerevisiae cells and to select PEF conditions optimal for the highest uptake of this element. Iron ions were accumulated most efficiently when their source was iron (III) nitrate. When the following conditions of PEF treatment were used: voltage 1500 V, pulse width 10 μs, treatment time 20 min, and a number of pulses 1200, accumulation of iron ions in the cells from a 20 h-culture reached a maximum value of 48.01 mg/g dry mass. Application of the optimal PEF conditions thus increased iron accumulation in cells by 157% as compared to the sample enriched with iron without PEF. The second derivative of the FTIR spectra of iron-loaded and -unloaded yeast cells allowed us to determine the functional groups which may be involved in metal ion binding. The exposure of cells to PEF treatment only slightly influenced the biomass and cell viability. However, iron-enriched yeast (both with or without PEF) showed lower fermentative activity than a control sample. Thus obtained yeast biomass containing a high amount of incorporated iron may serve as an alternative to pharmacological supplementation in the state of iron deficiency.


2021 ◽  
Vol 4 (11(112)) ◽  
pp. 6-16
Author(s):  
Ayana Serikbaeva ◽  
Bagimkul Tnymbaeva ◽  
Maryna Mardar ◽  
Nataliіa Tkachenko ◽  
Saniya Ibraimova ◽  
...  

In order to determine the influence of temperature and time of germination of the Bogatyr variety buckwheat on a change in the content of vitamins E, C, and B group, the germination parameters were optimized when developing a new type of seasoning. To optimize the germination parameters, the response surface methodology was used. The maximum total content of B, E, and C group vitamins in the sprouted buckwheat (4.591 mg/100 g) was observed at a temperature of 21.5 °C and the duration of germination of 3 days. The Bogatyr variety buckwheat was sprouted for 4 days. Changes in the nutritional and biological value of the sprouted grains were registered after 24 hours. Based on the comparative chemical analysis, it was established that the content of protein, fiber, vitamins, amino acids increases during the germination of buckwheat in comparison with the control sample. The protein content on day 4 increases by 1.38 times compared to control. At the same time, the mass fraction of carbohydrates on day 4 is reduced by 1.57 times; the mass fraction of fat ‒ by 2 times. It was established that the prototype seasoning that contains 30 % of sprouted buckwheat is characterized by a higher content of protein, vitamins, micro-and macronutrients compared to the control sample (without the addition of sprouted buckwheat). Adding the sprouted buckwheat grain to the seasoning has made it possible to increase by 25 % the antioxidant activity of the finished product compared to the control sample, which is 259.09 and 383.72 mg/100 g, respectively. In terms of safety indicators, the new product fully complies with the requirements for sanitary and hygienic safety. The results reported here give reasons to recommend the production of a new type of seasonings of enhanced nutritional value based on the sprouted Bogatyr variety buckwheat, which could expand and improve the quality of nutrition


2018 ◽  
Vol 25 (14) ◽  
pp. 14097-14105 ◽  
Author(s):  
Stéphane Pfendler ◽  
Thomas Munch ◽  
Faisl Bousta ◽  
Laurence Alaoui-Sosse ◽  
Lotfi Aleya ◽  
...  

2020 ◽  
Vol 8 (5) ◽  
pp. 655 ◽  
Author(s):  
Santiago Benito

The combined use of Lachancea thermotolerans and Schizosaccharomyces pombe is a new winemaking biotechnology that aims to solve some modern industrial oenology problems related to warm viticulture regions. These areas are characterized for producing musts with high levels of sugar that can potentially be converted into wines with elevated ethanol contents, which are usually associated with high pH levels. This biotechnology was reported for the first time in 2015, and since then, several scientific articles have been published regarding this topic. These reported scientific studies follow an evolution similar to that performed in the past for Saccharomyces cerevisiae and Oenococcus oeni; they start by reporting results for basic winemaking parameters at the beginning, later continuing with more advanced parameters. This review compares the results of different researchers that have applied this new biotechnology and have studied wine quality parameters such as ethanol, glycerol, malic acid, lactic acid, amino acids, aroma compounds, or anthocyanins. It is shown that the new biotechnology is repeatedly reported to solve specific winemaking problems such as the lack of acidity, biogenic amines, ethyl carbamate, or undesirable color losses. Such results highlight this biotechnology as a promising option for warm viticulture areas.


2020 ◽  
Vol 38 (11) ◽  
pp. 1231-1238
Author(s):  
Anita Kaliszewicz ◽  
Michał Winczek ◽  
Kamil Karaban ◽  
Dominik Kurzydłowski ◽  
Maria Górska ◽  
...  

The contamination of freshwater ecosystems with microfibres has not yet been studied in Poland. We analysed samples from a river and three lakes located in central and northeastern Poland. A significantly higher number of fibres were reported in the river, which runs through large cities, compared with the lake situated within the Landscape Park. Fibres smaller than 1.0 mm dominated, especially in the river where they constituted 39% of all fibres detected. We found more microplastics (⩽ 4930 fibres·m−3) by using a mesh size of 20 µm compared with other studies of inland waters. The use of Raman spectroscopy allowed us to identify conventional plastic polymers: polyethylene terephthalate, polyester and polyurethane. We estimated that up to 25 g of microplastic in the form of fibres might be in the lake water under the surface. We found microplastic fibres in Majcz Lake situated within the Masurian Landscape Park. This suggests that microfibres are carried by the wind and rain and enter freshwater isolated from sewage outlets. By using the control sample and an air-test of microfibres in the laboratory, we observed that there is a high probability of contamination with microplastic in the field samples (up to 30% of all fibres detected). The contamination risk noted from the samples cannot be ignored; this could be particularly important for analysis of microplastic in remote freshwater ecosystems.


LWT ◽  
2011 ◽  
Vol 44 (1) ◽  
pp. 191-198 ◽  
Author(s):  
Marcela Schenk ◽  
Silvia Raffellini ◽  
Sandra Guerrero ◽  
Guillermo A. Blanco ◽  
Stella Maris Alzamora

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Tindibale L. Edward ◽  
M. S. K. Kirui ◽  
Josiah O. Omolo ◽  
Richard G. Ngumbu ◽  
Peter M. Odhiambo

This study investigated the effects of ultraviolet-A (UV-A) and ultraviolet-C (UV-C) light on the mechanical properties in oyster mushrooms during the growth. Experiments were carried out with irradiation of the mushrooms with UV-A (365 nm) and UV-C (254 nm) light during growth. The exposure time ranged from 10 minutes to 60 minutes at intervals of 10 minutes and irradiation was done for three days. The samples for experimental studies were cut into cylindrical shapes of diameter 12.50 mm and thickness 3.00 mm. The storage modulus, loss modulus, and loss factor of the irradiated samples and control samples were determined for both UV bands and there was a significant difference between the storage modulus, loss modulus, and loss factor of the irradiated samples by both UV bands with reference to the control sample, P<0.05. UV-C light irradiated samples had higher loss modulus and loss factor but low storage modulus as temperature increased from 35 to 100°C with respect to the control sample while UV-A light irradiated samples had lower loss modulus, low loss factor, and higher storage modulus than UV-C irradiated samples.


2017 ◽  
Vol 39 (3) ◽  
Author(s):  
TAÍSA CERATTI TREPTOW ◽  
FERNANDA WOUTERS FRANCO ◽  
LAURA GIZELE MASCARIN ◽  
LUISA HELENA RYCHECKI HECKTHEUER ◽  
CLÁUDIA KAEHLER SAUTTER

ABSTRACT Grape juice has been widely studied due to the presence of phenolic compounds and its beneficial effects on human health. Ultraviolet irradiation C (UV-C) can increase the content of phenolic compounds and anthocyanins and contribute to sensory acceptability. The aim of this study was to evaluate the effect of different doses of ultraviolet irradiation C (UV-C) on ‘Trebbiano’, ‘Niagara Branca’, ‘Isabel’ and ‘Cabernet Sauvignon’ grapes, as well as effect of the storage period. Juices were elaborated and evaluated for physicochemical analyses, and for the sensorial analysis in irradiated samples. In ‘Niagara Branca’ and ‘Trebbiano’ cultivars, storage and irradiation promoted few physicochemical alterations, and sensorially, irradiation reduced the intensity of flavor and color attributes. In juices from ‘Isabel’ and ‘Cabernet Sauvignon’ cultivars, the storage period led to the concentration of sugars and irradiation influenced physicochemical parameters and increased the intensity of aroma attribute at dose of 2 kJ m-2. Thus, UV-C irradiation contributes little for the improvement of white grape juices; however, it favors some sensory attributes in red grape juice, requiring further studies to elucidate the influence of UV-C irradiation on the phenolic and volatile composition of grape juice.


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