Efeito de polímeros naturais na conservação de banana CV Caturra / Effect of natural polymers in banana CV caturra conservation

Este trabalho teve como objetivo avaliar o efeito de filmes formados por pectina, albúmen de ovo, carragena, gelatina, fécula de batata, xantana e amido de milho na conservação de banana cv. Caturra. As bananas foram sanitizadas e imersas em soluções filmogênicas de pectina (2%), albúmen de ovo (100%), carragena (2%), gelatina (5%), fécula de batata (2%) com glicerol (0,7%), xantana (1%), amido de milho (2%) com glicerol (0,7%) e o controle (0%), sendo armazenadas a 18ºC a 80% de UR por 8 dias. As bananas revestidas foram avaliados de acordo com a perda de massa, taxa de perda de massa, sólidos solúveis totais, cor (luminosidade e croma b*) e firmeza, nos tempos de zero hora, 2, 6, 7 e 8 dias. Ao final do período de armazenamento as bananas cv Caturra revestidas com filmes de pectina promoveram menor perda de massa e se mantiveram dentro do limite permitido (7%) até os 4,9 dias. O revestimento com carragena mostrou menor aumento dos sólidos solúveis totais, já os filmes de albúmen proporcionaram menores reduções da firmeza e variações da coloração amarela e o revestimento com fécula de batata melhorou a luminosidade nos frutos. Este aspecto mostra uma contribuição dos filmes na manutenção da qualidade da banana cv. Caturra. No entanto, outros parâmetros de qualidade devem ser avaliados, buscando conhecer outros efeitos desses filmes sobre a banana.

Apple Aminoacid Profile and Yeast Strains in the Formation of Fusel Alcohols and Esters in Cider Production.

The amino acid profile in dessert apple must and its effect on the synthesis of fusel alcohols and esters in cider were established by instrumental analysis. The amino acid profile was performed in nine apple musts. Two apple musts with high (>150 mg/L) and low (<75 mg/L) nitrogen content, and four enological yeast strains, were used in cider fermentation. The aspartic acid, asparagine and glutamic acid amino acids were the majority in all the apple juices, representing 57.10% to 81.95%. These three amino acids provided a high consumption (>90%) during fermentation in all the ciders. Principal component analysis (PCA) explained 81.42% of data variability and the separation of three groups for the analyzed samples was verified. The ciders manufactured with low nitrogen content showed sluggish fermentation and around 50% less content of volatile compounds (independent of the yeast strain used), which were mainly 3-methyl-1-butanol (isoamyl alcohol) and esters. However, in the presence of amino acids (asparagine, aspartic acid, glutamic acid and alanine) there was a greater differentiation between the yeasts in the production of fusel alcohols and ethyl esters. High contents of these aminoacids in dessert apple musts are essential for the production of fusel alcohols and most of esters by aromatic yeasts during cider fermentation.

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.