Population dynamics of mixed cultures of yeast and lactic acid bacteria in cider conditions

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.

Classification of juices and fermented beverages made from unripe, ripe and senescent apples based on the aromatic profile using chemometrics.

The aim of this study was to assess differences between apple juices and fermented apple beverages elaborated with fruits from different varieties and at different ripening stages in the aroma profile by using chemometrics. Ripening influenced the aroma composition of the apple juice and fermented apple. For all varieties, senescent fruits provided more aromatic fermented apple beverages. However, no significant difference was noticed in samples made of senescent or ripe fruits of the Lisgala variety. Regarding the juices, ripe Gala apple had the highest total aroma concentration. Ethanal was the major compound identified in all the samples, with values between 11.83mg/L (unripe Lisgala juice) and 81.05mg/L (ripe Gala juice). 3-Methyl-1-butanol was the major compound identified in the fermented juices. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were applied and classified the juices and fermented juices based on physicochemical and aroma profile, demonstrating their applicability as tools to monitor the quality of apple-based products.

Elaboração de fermento frisante de maçã com características semelhantes à sidra francesa / Elaboration of a sparkling apple wine with characteristics similar to the french cider

Este trabalho teve como objetivo elaborar fermentado frisante de maçã com características de qualidade baseadas na sidra francesa e na preferência do consumidor brasileiro. Utilizou-se suco despectinizado da cultivar Gala no processo de crioconcentração e na elaboração do fermentado. Diluiu-se o grau alcoólico para 4,5% GL, sendo as correções de açúcares com o crioconcentrado e de acidez com ácido cítrico efetuadas com base no resultado da preferência dos consumidores pelo teste de ordenação. Definiu-se a espuma após teste com alginato de propileno glicol. O teor residual de açúcares corrigido com o suco crioconcentrado foi de 50 g.L, aumentando seu teor de fenólicos e sua atividade antioxidante. Corrigiu-se a acidez para 0,75 g.100mL, tornando-a semelhante à da sidra francesa. A espuma, próximo ao natural, porém mais persistente foi conseguida com adição de alginato de propileno glicol na proporção de 4,0 g.hL. O índice de aceitação do produto foi de 81,63% com tendência de intenção de compra de aproximadamente 85%, indicando que o produto atende ao gosto do consumidor. Desta forma, elaborou-se bebida com características da sidra francesa com ótima aceitação pelos consumidores e potencial de mercado.