The phenolic compounds of red wines are responsible for their color, astringency, and antioxidant properties. The fermentative yeasts might be used to modulate wines in terms of their color, aroma ...and probably healthy properties. In this study, six non-
species were tested because they might enhance the properties of red Tempranillo wines from Rioja. The results confirmed that the anthocyanins and stilbenes composition of wine can be modulated with the use of a specific fermentation starter.
,
,
, and
achieved the greatest improvements of the monomeric anthocyanin composition, and the latter three yeast species achieved the best results of stilbene composition when compared to
and the other non-
yeasts. Overall, results suggested that the use of
and
as fermentation starters could be of great interest to achieve wines with better color and likely healthy properties.
During wine stabilization, control of the microbial population is required in order to ensure a quality wine. Pulsed Electric Field (PEF) was applied to commercial wines in a continuous flow to ...reduce the amount of SO2 added after the end of malolactic fermentation to manage microbial populations. Samples of wine from three commercial wineries of the Rioja Qualified Designation of Origin were treated with 30 mg/L SO2, with 15 mg/L SO2 and PEF, and only with PEF. The inactivation of the microbiota with the PEF treatment was greater than the inactivation achieved with SO2 four days after treatment. Six months later, the lactic acid bacteria population was still viable in some of the wines. Regarding the physicochemical characterization of the wines, the PEF treatment was positive for quality because the wines had greater color intensity and lower volatile acidity. Moreover, organoleptic analysis indicated different scoring depending mainly on the characteristics of the original wine. Despite these positive results, further studies are advisable to optimize the control of lactic acid bacteria.
The application of PEF during wine stabilization after MLF can be a viable alternative for the oenological industry to reduce the SO2 dosage used in winemaking.
•PEF technology was effective for reducing the SO2 dosage.•PEF technology achieved an important inactivation of microorganisms.•LAB remained viable in wines six months after treatment.•PEF treatment caused an increase in the color intensity.•PEF treatments did not alter the organoleptic wine quality.
Dadas las necesidades, expectativas y experiencias de las nuevas generaciones, se han agudizado los discursos que hablan acerca de la educación de calidad y de las posibilidades de generar ambientes ...y políticas para concretar este ideal. Sin embargo, la realidad de la sociedad actual reclama otro tipo de prácticas pedagógicas al interior de las instituciones de educación básica y media, especialmente, en lo que a Educación Sexual1 se refiere, es decir, una ES renovada, despojada de los estereotipos, los prejuicios y los diferentes enfoques que por décadas han perpetuado modelos formativos basados en enfoques preventivos, moralistas y heteronormativos. Por lo anterior, surge esta investigación2,3, la cual tiene por objetivo analizar los significados críticos presentes en las Políticas Públicas de ES con respecto a las prácticas formativas en los colegios públicos de Bogotá. Así, el presente artículo evidencia el resultado de la revisión y análisis de 50 artículos resultados de investigaciones relacionadas con ES; situando el interés en los estudios realizados en Argentina, Chile, Brasil, Colombia, Costa Rica, Venezuela, Ecuador, México, Cuba y Perú con el fin de construir un panorama de la ES en la región. A partir de lo anterior se puede concluir que existen falencias en la formación docente respecto a temas relacionados con la sexualidad y su enseñanza. De igual forma, es necesario generar un cambio en las prácticas pedagógicas de Educación Sexual Integral (ESI)4, para transcender a los discursos heteronormativos y las miradas biopolíticas que mantienen los roles y los estereotipos de género.
This study was aimed to measure the impact of the application of a bio-fungicide against
on the microbiota involved in the alcoholic fermentation (AF) of Tempranillo Rioja wines. For this purpose, a ...bio-fungicide composed of the biological control bacterium
QST713 was applied to the vineyard. The microbial diversity was analyzed from grape biofilm to wine. Impact on microbial diversity was measured employing indexes assessed with the software PAST 3.10 P.D. Results were compared to non-treated samples and to samples treated with a chemical fungicide mainly composed by fenhexamid. Overall, the impact of the biological-fungicide (bio-fungicide) on the microbial diversity assessed for grape biofilm and for musts was not remarkable. Neither of the tested fungicides enhanced the growth of any species or acted against the development of any microbial groups. The bio-fungicide had no significant impact on the wine microbiota whereas the chemical fungicide caused a reduction of microbial community richness and diversity. Although environmental threats might generate a detriment of the microbial species richness, in this study the tested bio-fungicide did not modify the structure of the microbial community. Indeed, some of the
applied at the grape surface, were detected at the end of the AF showing its resilience to the harsh environment of the winemaking; in contrast, its impact on wine quality during aging is yet unknown.
Carbonic maceration (CM) vinification is a very traditional method that allows saving energy without great equipment investment, obtaining high-quality wines. However, due to its particularities, CM ...winemaking implies a higher risk of microbial alteration. This work studies the evolution of bacterial population along carbonic maceration wines elaboration with and without yeast inoculation. In the same way, two strategies of yeast inoculation were studied: "pied de cuve" and Active Dry Yeasts (ADY) seed. For this purpose, three conditions were assayed: spontaneous fermentation (without inoculation), "pied de cuve" technology, and ADY inoculation. For each condition, two winemaking methods were compared: carbonic maceration and the standard method of destemming and crushing (DC). The bacterial evolution (lactic acid and acetic acid bacteria) was followed in different fermentation stages. Finally, the wines obtained were analysed (pH and volatile acidity). In the non-inoculated wines produced by CM, high development of the bacterial population was observed (counts of acetic acid bacteria around 4.3 log cfu/mL), and finished wines presented high values of volatile acidity (>1.5 g/L), which did not occur in the inoculated vinifications (counts of acetic acid bacteria around 1.5 log cfu/mL and 0.5 g/l of volatile acidity). Thus, the control of yeast population, as a "pied de cuve" as ADY seed, seems to be an effective tool to avoid bacterial alterations in CM vinifications.
One of the alternatives to SO2 as an antimicrobial is the use of bioprotection yeasts, which colonize the medium preventing the proliferation of undesirable microorganisms. In this work, the ...bioprotective effect of a mixed inoculum formed by Torulaspora delbrueckii/Lachancea thermotolerans during fermentation was evaluated. For this purpose, fermentations were carried out using this mixed inoculum and the populations of yeasts, lactic bacteria and acetic bacteria, and the physical–chemical parameters of the wines obtained were studied. The results were compared with those obtained in spontaneous fermentation with and without SO2. The different fermentation strategies caused a differentiation in the yeast species present during fermentation. Regarding populations of lactic acid bacteria, results showed that the effect of the addition of the mixed inoculum was comparable to that exerted by SO2. On the other hand, due to the high sensitivity of acetic acid bacteria to SO2, the sulfite vinifications showed a lower population of acetic acid bacteria in the early stages of fermentation, followed by the vinifications with the mixed inoculum.
Four different treatments of pulsed electric field (PEF) technology were tested in a continuous-flow system for inactivating 25 species of yeast, lactic acid bacteria and acetic acid bacteria ...associated with wines. Overall, the reached inactivation varied from 0.64 to 4.94logunits. Curiously, it was determined that the application of higher specific energy did not provide significant declination of yeast population, although significantly different inactivations were determined for bacteria. The inactivation of bacteria highly depended on each species and results corroborated different sensitivity of two Oenococcus oeni strains what could be related with their genetic characteristics.
•PEF was tested in continuous-flow over 25 yeast, LAB and AAB species from wine.•Four treatments were applied, varying the inactivation from 0.64 to 4.94logunits.•High specific energy did not conduct significant high inactivation in yeasts.•Significantly different inactivations were found in bacteria, especially in AAB.•Oenococcus oeni strains had different sensitivity to PEF treatments.
Nitrogen supplementation in musts or during the alcoholic fermentation is a common practice to promote fermentations. In this study, the impact of the supplementation of two different sources of ...nitrogen during Tempranillo red wine elaboration was studied. Mineral and organic nitrogen was added after the exponential yeast growth phase and during winemaking, examining its impact on the alcoholic and malolactic fermentation development, on the aromatic wine composition and on the nitrogenous wine composition. The nitrogen supplementation did not provide neither significant advantages in kinetics and fermentations time, nor differences in the chemical wine composition. The aromatic composition of the wines improved with the addition of inorganic nitrogen, although its organoleptic evaluation was not favored. Moreover, the concentration of amino acids in wines increased slightly after the malolactic fermentation and significantly during the stabilization time, especially with organic nitrogen addition. However, the synthesis of biogenic amines did not increase in wines neither after the malolactic fermentation, nor after the storage period.
Indigenous lactic acid bacteria (LAB) communities have been analyzed for three years (2006, 2007 and 2008) during alcoholic (AF) and malolactic (MLF) fermentations of Tempranillo wines in ten ...wineries of La Rioja. The results showed that analytical composition of wines and physical–chemical conditions of elaboration influenced the LAB populations, the MLF duration and the percentage of each isolated species and strains. The highest diversity of LAB species was observed during AF in all the wineries. Oenococcus oeni was present in all studied stages of the fermentation process, being the predominant species at final AF stage. The study of 925 isolates of O. oeni by Pulsed Field Gel Electrophoresis (PFGE) allowed the detection of a total of 112 distinct genotypes. Most fermentation stages of both AF and MLF showed mixed O. oeni strain populations, so that there were different genotypes able to share their ecological niche or tank in spontaneous MLF. The frequency of participation of each genotype varied either from year to year or from winery to winery. Otherwise, seven genotypes were detected in the three studied years and in at least three out of the ten studied wineries, being four of them also present in the three studied subzones of this region. These results suggest the existence of an endemic microbiota in this region, the adaptation of indigenous O. oeni strains to the winery conditions every year and the interest of selecting predominant genotypes in order to preserve the biodiversity and peculiarity of these wines.
► The highest number of LAB species was detected during alcoholic fermentation. ► Mixed populations and great O. oeni strain diversity were observed. ► Genotypes at each winery sometimes were distinctive and others were coincident. ► An endemic microbiota adapted to ecological conditions of this region was surmised. ► Dominant genotypes were interesting to selection process and preserve biodiversity.
The use of non-Saccharomyces yeasts in sequential fermentations with S. cerevisiae has been proposed to improve the organoleptic characteristics involved in the quality of wine. The present study set ...out to select a non-Saccharomyces inoculum from the D.O.Ca. Rioja for use in winemaking. Strains included in the study belonged to Torulaspora delbrueckii, Lachancea thermotolerans, Metschnikowia pulcherrima, Zygosaccharomyces bailii, Williopsis pratensis, Debaryomyces hansenii, Pichia kluyveri, Sporidiobolus salmonicolor, Candida spp., Cryptococcus spp. and two mixed inocula of Lachancea thermotolerans-Torulaspora delbrueckii in a 30/70 ratio. In the first stage of the process, SO2 resistance and presence of enzymatic activities related to wine aroma and wine color and fining (esterase, esterase-lipase, lipase, leucine arylamidase, valine arylamidase, cystine arylamidase, β-glucosidase, pectinase, cellulose, xylanase and glucanase) were studied. In the later stages, selection criteria such as fermentative behavior, aroma compound production or influence on phenolic compounds were studied in laboratory scale vinifications. Taking into account the results obtained in the different stages of the process, a mixed inoculum of Lachancea thermotolerans-Torulaspora delbrueckii in a 30/70 ratio was finally selected. This inoculum stood out for its high implantation capacity, the production of compounds of interest such as glycerol and lactic acid and the consequent modulation of wine acidity. Given these characteristics, the selected inoculum is suitable for the production of quality wines.
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