RESUMEN
ABSTRACT: This study aimed to know the biodiversity of non-Saccharomyces yeasts in Brazilian apples must with potential to improve of the aromatic quality of ciders. The strains were isolated from thirty-five (35) Gala and Fuji apple musts from different locations from south region of Brazil. Forty-five (45) strains were isolate and identified by PCR analysis. Results indicated ten (10) species: Candida oleophila, Candida parapsilosis, Candida tropicalis, Clavispora lusitaniae, Hanseniaspora guilliermondii, Hanseniaspora uvarum, Lodderomyces elongisporus, Pichia anomala, Pichia fermentans and Rhodotorula mucilaginosa. The genus Rhodotorula sp., Lodderomyces sp. and Clavispora sp. constituted 71.2% of the strains identified. The following strains, C. oleophila, R. mucilaginosa, P. fermentans, H. uvarum and H. guilliermondii were selected in qualitative tests due the fruity aroma production by trained team in the aromatic assessment of cider.
RESUMO: Este estudo teve como objetivo conhecer a biodiversidade de leveduras não-Saccharomyces em maçãs com potencial para a melhoria da qualidade aromática da sidra brasileira. As cepas foram isoladas de trinta e cinco (35) mostos de maçã Gala e Fuji de diferentes locais da região Sul do Brasil. Quarenta e cinco (45) cepas foram isoladas e identificadas por análise de PCR. Os resultados indicaram dez (10) espécies: Candida oleophila, Candida parapsilosis, Candida tropicalis, Clavispora lusitaniae, Hanseniaspora guilliermondii, Hanseniaspora uvarum, Lodderomyces elongisporus, Pichia anomala, Pichia fermentans e Rhodotorula mucilaginosa. Três desses gêneros (Rhodotorula sp., Lodderomyces sp. e Clavispora sp.) juntos constituíram 71,2% das cepas identificadas. Entre estas cepas, C. oleophila, R. mucilaginosa, P. fermentans, H. uvarum e H. guilliermondii foram selecionadas em teste qualitativo devido a produção de aroma frutado, indicando potencial para a produção de compostos aromáticos na sidra.
RESUMEN
The objective of this work was to study the malolactic bioconversion in low acidity cider, according Brazilian conditions. The apple must was inoculated with Saccharomyces cerevisiae or S. cerevisiae with Oenococcus oeni. The control contained the indigenous microorganisms. Fermentation assays were carried out with clarified apple must from the Gala variety. At the beginning of fermentation, there was a fast growth of the non-Saccharomyces yeast population. Competitive inhibition occurred in all the assays, either with inoculated or indigenous populations of the yeast. The lactic acid bacteria count was ca. 1.41·10²CFU/mL at the beginning and 10(6)CFU/mL after yeast cells autolysis. The lactic bacteria O. oeni reached the highest population (10(7)CFU/mL) when added to the apple must after the decline of the yeast. The malic acid was totally consumed during the alcoholic fermentation period (80.0 to 95.5 %) and lactic acid was still synthesized during the 35 days of malolactic fermentation. These results could be important in order to achieve a high quality brut, or sec cider obtained from the dessert apple must.