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1.
Environ Sci Process Impacts ; 24(10): 1957, 2022 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-35983843

RESUMO

Correction for 'Effect of the orientation and fluid flow on the accumulation of organotin compounds to Chemcatcher passive samplers' by H. Ahkola et al., Environ. Sci.: Processes Impacts, 2015, 17, 813-824, https://doi.org/10.1039/C4EM00585F.

2.
Food Microbiol ; 98: 103644, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33875226

RESUMO

The potential of yeasts isolated from traditional chichas as starter cultures, either for controlled production of the native beverage or for industrial beer production, has been investigated. Three S. cerevisiae strains and one T. delbrueckii strain isolated from four different Ecuadorian chichas were compared to ale and lager beer strains with respect to fermentation performance, sugar utilisation, phenolic off-flavour production, flocculation and growth at low temperature. Fermentations were performed in 15 °P all-malt wort and in a model chicha substrate at 12 °C and 20 °C. Tall-tube fermentations (1.5 L) were also performed with both substrates to assess yeast performance and beer quality. Among the strains tested, only one Ecuadorian S. cerevisiae strain was able to ferment the wort sugars maltose and maltotriose. Fermentations with all Ecuadorian strains were poor in wort at 12 °C relative to 20 °C, but were similar in model chicha substrate at both temperatures. The aromatic profile was different between species and strains. These results indicate the potential of yeasts derived from traditional Andean fermented beverages for commercial applications. One of the chicha strains demonstrated traits typical of domesticated brewery strains and could be suitable for ale fermentation, while the other strains may have potential for low-alcohol beer or chicha production.


Assuntos
Bebidas Alcoólicas/microbiologia , Saccharomyces cerevisiae/metabolismo , Trissacarídeos/metabolismo , Zea mays/microbiologia , Cerveja/microbiologia , Equador , Fermentação , Aromatizantes/química , Aromatizantes/metabolismo , Microbiologia de Alimentos , Maltose/metabolismo , Saccharomyces cerevisiae/classificação , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Leveduras/classificação , Leveduras/genética , Leveduras/metabolismo , Zea mays/metabolismo
3.
Annu Rev Food Sci Technol ; 11: 23-44, 2020 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-31951488

RESUMO

Yeasts directly impact the efficiency of brewery fermentations as well as the character of the beers produced. In recent years, there has been renewed interest in yeast selection and development inspired by the demand to utilize resources more efficiently and the need to differentiate beers in a competitive market. Reviewed here are the different, non-genetically modified (GM) approaches that have been considered, including bioprospecting, hybridization, and adaptive laboratory evolution (ALE). Particular emphasis is placed on the latter, which represents an extension of the processes that have led to the domestication of strains already used in commercial breweries. ALE can be used to accentuate the positive traits of brewing yeast as well as temper some of the traits that are less desirable from a modern brewer's perspective. This method has the added advantage of being non-GM and therefore suitable for food and beverage production.


Assuntos
Cerveja , Fermentação , Laboratórios/organização & administração , Saccharomyces/metabolismo
4.
FEMS Yeast Res ; 17(4)2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28582493

RESUMO

The brewing industry is experiencing a period of change and experimentation largely driven by customer demand for product diversity. This has coincided with a greater appreciation of the role of yeast in determining the character of beer and the widespread availability of powerful tools for yeast research. Genome analysis in particular has helped clarify the processes leading to domestication of brewing yeast and has identified domestication signatures that may be exploited for further yeast development. The functional properties of non-conventional yeast (both Saccharomyces and non-Saccharomyces) are being assessed with a view to creating beers with new flavours as well as producing flavoursome non-alcoholic beers. The discovery of the psychrotolerant S. eubayanus has stimulated research on de novo S. cerevisiae × S. eubayanus hybrids for low-temperature lager brewing and has led to renewed interest in the functional importance of hybrid organisms and the mechanisms that determine hybrid genome function and stability. The greater diversity of yeast that can be applied in brewing, along with an improved understanding of yeasts' evolutionary history and biology, is expected to have a significant and direct impact on the brewing industry, with potential for improved brewing efficiency, product diversity and, above all, customer satisfaction.


Assuntos
Cerveja/análise , Genoma Fúngico , Engenharia Metabólica/métodos , Pichia/genética , Saccharomyces cerevisiae/genética , Saccharomyces/genética , Evolução Biológica , Quimera , Cruzamentos Genéticos , Fermentação , Humanos , Odorantes/análise , Pichia/metabolismo , Saccharomyces/metabolismo , Saccharomyces cerevisiae/metabolismo , Zygosaccharomyces/genética , Zygosaccharomyces/metabolismo
5.
Environ Sci Process Impacts ; 17(4): 813-24, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25758414

RESUMO

Monitoring of harmful substances in an aquatic environment is based on spot sampling which is the only sampling technique accepted by environmental authorities in the European Union. Still the implementation of the European Union Water Framework Directive (WFD) requires novel sampling tools for monitoring priority pollutants since their concentrations in natural waters can often remain below the limit of detection when using the conventional spot sampling method. However, this does not necessarily mean that the pollutant is not present in the aquatic environment. Many chemicals that are considered to be harmful are bioaccumulative and can affect, e.g., reproduction of aquatic organisms even at very low concentration levels. Also the timing is crucial since with spot sampling the pulse of harmful substances can easily be missed. Passive samplers collect the compounds for a certain amount of time which allows the concentrations in the sampler to rise to the measurable level where they are easy to detect. Organotin compounds (OTCs) have been widely used as plastic stabilizers and antifouling agents in ship paints and in many industrial processes. Among the OTCs, tributyltin is listed as a WFD priority substance. In this study a small-scale flow simulation around the Chemcatcher passive sampler was performed to visualize the flow streamlines in the vicinity of the sampler and to study the pressure experienced by the receiving phase in different sampler positions. With laboratory experiments the sampling rates for each OTC were determined and the effect of the flow velocity and sampler orientation on the accumulation of OTCs is discussed. The pressure changes were observed on the surface of the receiving phase in simulations with varying sampler orientations. Despite that, the laboratory experiments discovered no difference in the accumulation of compounds when varying the sampler orientation. The concentrations of OTCs in the surrounding water calculated from the passive sampling results were equivalent to the spot sampling ones. Hence, the Chemcatcher passive sampler provides a practical tool for the implementation of WFD.


Assuntos
Monitoramento Ambiental/instrumentação , Compostos Orgânicos de Estanho/análise , Movimentos da Água , Poluentes Químicos da Água/análise , Rios/química
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