In this study, the presence of non-conventional yeast associated with vineyards located between latitudes 30°S and 36°S was examined, including the valleys of Limarí, Casablanca, Maipo, Colchagua, Maule, and Itata. The microbial fingerprinting in each valley was examined based on the specific quantification of yeast of enological interest. Grape–berries were sampled to evaluate the presence and load of non-conventional yeast with enological potential, such as Metschnikowia, Hanseniaspora, Torulaspora, Debaryomyces, Meyerozyma, and Rhodotorula. These yeasts were present in all vineyards studied but with varying loads depending on the valley sampled. No identical fingerprints were observed; however, similarities and differences could be observed among the microbial profiles of each valley. A co-variation in the loads of Metschnikowia and Hanseniaspora with latitude was observed, showing high loads in the Casablanca and Itata valleys, which was coincident with the higher relative humidity or rainfall of those areas. Non-conventional yeasts were also isolated and identified after sequencing molecular markers. Potentially good aromatic properties were also screened among the isolates, resulting in the selection of mostly Metschnikowia and Hanseniaspora isolates. Finally, our results suggest that microbial terroir might be affected by climatic conditions such as relative humidity and rainfall, especially impacting the load of non-conventional yeast. In this study, the microbial fingerprint for yeast in Chilean vineyards is reported for the first time revealing an opportunity to study the contribution of this assembly of microorganisms to the final product.
Artículo de publicación ISIThe concentration of proanthocyanidins from twenty red wines from cv. Cabernet Sauvignon, five ros e
wines from cv. Cabernet Sauvignon and five white wines from cv. Sauvignon Blanc was quantified using
four analytical methodologies, and their relationship with the perceived astringency was investigated. Proanthocyanidin
concentrations were determined by a methylcellulose precipitation assay, a protein precipitation
assay and two colourimetric methods (Bate-Smith and vanillin assay). The four methodologies
showed high repeatability but differed widely in proanthocyanidin concentrations. The methylcellulose
and protein precipitation assays could not quantify proanthocyanidins in ros e and white wines. The protein
precipitation assay gave the lowest concentration of proanthocyanidins in all of the red wines. The
methylcellulose precipitation assay (r = 0.7725; r2 = 0.59) and the protein precipitation assay (r = 0.6828;
r2 = 0.47) showed a strong correlation with the perceived astringency compared with the colourimetric
methods. The strong correlation of the methylcellulose precipitation method with the perceived astringency
could be a useful tool to estimate red wine astringency
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.