The effects of co- and sequential inoculation of Torulaspora delbrueckii and Pichia kluyveri on chemical compositions of durian wine

2017 ◽  
Vol 101 (21) ◽  
pp. 7853-7863 ◽  
Author(s):  
Yuyun Lu ◽  
Marilyn Kai Wen Voon ◽  
Jian-Yong Chua ◽  
Dejian Huang ◽  
Pin-Rou Lee ◽  
...  
2019 ◽  
Vol 7 (6) ◽  
pp. 164 ◽  
Author(s):  
Inês Oliveira ◽  
Vicente Ferreira

The goal of this study is to assess to what extent non-Saccharomyces yeasts can introduce aromatic changes of industrial interest in fermentative, varietal and aged aromas of wine. Aroma precursors from Riesling and Garnacha grapes were extracted and used in two independent sequential experiments. Synthetic musts were inoculated, either with Saccharomyces cerevisiae (Sc) or with Pichia kluyveri (Pk), Torulaspora delbrueckii (Td) or Lachancea thermotolerans (Lt), followed by Sc. The fermented samples were subjected to anoxic aging at 50 °C for 0, 1, 2 or 5 weeks before an aroma analysis. The fermentative aroma profiles were consistently changed by non-Saccharomyces: all strains induced smaller levels of isoamyl alcohol; Pk produced huge levels of aromatic acetates and can induce high levels of fatty acids (FA) and their ethyl esters (EE); Td produced large levels of branched acids and of their EE after aging, and induced smaller levels of FA and their EE; Lt produced reduced levels of FA and their EE. The varietal aroma was also deeply affected: TDN (1,1,6-trimethyl-1,2- dihydronaphthalene) levels in aged wines were reduced by Pk and enhanced by Lt in Garnacha; the levels of vinylphenols can be much reduced, particularly by Lt and Pk. TD and Lt can increase linalool and geraniol in young, but not in aged wines.


2016 ◽  
Vol 243 (4) ◽  
pp. 681-688 ◽  
Author(s):  
Laura Medina-Trujillo ◽  
Elena González-Royo ◽  
Nathalie Sieczkowski ◽  
José Heras ◽  
Joan Miquel Canals ◽  
...  

2016 ◽  
Vol 7 ◽  
pp. 02024
Author(s):  
Laura Medina-Trujillo ◽  
Elena González-Royo ◽  
Nathalie Sieczkowski ◽  
José Heras ◽  
Francesca Fort ◽  
...  

2020 ◽  
Vol 8 (9) ◽  
pp. 1349
Author(s):  
M. Antonia Álvarez-Fernández ◽  
Ilaria Carafa ◽  
Urska Vrhovsek ◽  
Panagiotis Arapitsas

Yeasts are the key microorganisms that transform grape juice into wine, and nitrogen is an essential nutrient able to affect yeast cell growth, fermentation kinetics and wine quality. In this work, we focused on the intra- and extracellular metabolomic changes of three aromatic amino acids (tryptophan, tyrosine, and phenylalanine) during alcoholic fermentation of two grape musts by two Saccharomyces cerevisiae strains and the sequential inoculation of Torulaspora delbrueckii with Saccharomyces cerevisiae. An UPLC-MS/MS method was used to monitor 33 metabolites, and 26 of them were detected in the extracellular samples and 8 were detected in the intracellular ones. The results indicate that the most intensive metabolomic changes occurred during the logarithm cellular growth phase and that pure S. cerevisiae fermentations produced higher amounts of N-acetyl derivatives of tryptophan and tyrosine and the off-odour molecule 2-aminoacetophenone. The sequentially inoculated fermentations showed a slower evolution and a higher production of metabolites linked to the well-known plant hormone indole acetic acid (auxin). Finally, the production of sulfonated tryptophol during must fermentation was confirmed, which also may explain the bitter taste of wines produced by Torulaspora delbrueckii co-fermentations, while sulfonated indole carboxylic acid was detected for the first time in such an experimental design.


2013 ◽  
pp. 415-426 ◽  
Author(s):  
Panagiotis Tataridis ◽  
Anastasios Kanelis ◽  
Stilianos Logotetis ◽  
Elias Nerancis

Selected Saccharomyces yeast strains have been used for more than 150 years in brewing and for several decades in winemaking. They are necessary in brewing because of the boiling of the wort, which results in the death of all yeast cells, with the exception of some Belgian style beers (ex. Lambic), where the wort is left to be colonized by indigenous yeast and bacteria from the environment and ferment naturally. In winemaking their use is also pertinent because they provide regular and timely fermentations, inhibit the growth of indigenous spoilage microorganisms and contribute to the desired sensory characters. Even though the use of selected Saccharomyces strains provides better quality assurance in winemaking in comparison to the unknown microbial consortia in the must, it has been debated for a long time now whether the use of selected industrial Saccharomyces strains results in wines with less sensory complexity and ?terroir? character. In previous decades, non-Saccharomyces yeasts were mainly considered as spoilage/problematic yeast, since they exhibited low fermentation ability and other negative traits. In the last decades experiments have shown that there are some non-Saccharomyces strains (Candida, Pichia, Kluyveromyces, Torulaspora, etc) which, even though they are not able to complete the fermentation they can still be used in sequential inoculation-fermentation with Saccharomyces to increase sensory complexity of the wines. Through fermentation in a laboratory scale, we have observed that the overall effects of selected Torulaspora delbrueckii yeast strains, is highly positive, leading to products with pronounced sensory complexity and floral/fruity aroma in winemaking and brewing.


Fermentation ◽  
2019 ◽  
Vol 5 (3) ◽  
pp. 79 ◽  
Author(s):  
Ophélie Dutraive ◽  
Santiago Benito ◽  
Stefanie Fritsch ◽  
Beata Beisert ◽  
Claus-Dieter Patz ◽  
...  

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.


Author(s):  
D.I. Potter ◽  
M. Ahmed ◽  
K. Ruffing

Ion implantation, used extensively for the past decade in fabricating semiconductor devices, now provides a unique means for altering the near-surface chemical compositions and microstructures of metals. These alterations often significantly improve physical properties that depend on the surface of the material; for example, catalysis, corrosion, oxidation, hardness, friction and wear. Frequently the mechanisms causing these beneficial alterations and property changes remain obscure and much of the current research in the area of ion implantation metallurgy is aimed at identifying such mechanisms. Investigators thus confront two immediate questions: To what extent is the chemical composition changed by implantation? What is the resulting microstructure? These two questions can be investigated very fruitfully with analytical electron microscopy (AEM), as described below.


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