Aline M. Bortoletto

Congeners in sugar cane spirits aged in casks of different woods

The profile of volatile compounds and aging markers in sugar cane spirits aged for 36 months in casks made of 10 types of wood were studied. The ethanol content, volatile acidity, aldehydes, esters, higher alcohols, and methanol were determined. In addition, gallic, vanilic and syringic acids, siringaldehyde, coniferaldehyde, sinapaldehyde, vanillin, 5-hydroxymethylfurfural and furfural were identified and quantified. The profile of volatile compounds characterised aging in each type of wood. The beverage aged in oak cask achieved the highest contents of maturation-related congeners. The Brazilian woods, similar to oak, were jequitibá rosa and cerejeira, which presented the highest contents of some maturation-related compounds, such as vanillin, vanilic acid, syringaldehyde and sinapaldehyde. Although oak wood conferred more chemical complexity to the beverage, Brazilian woods, singly or complementarily, present potential for spirit characterisation and for improving the quality of sugar cane spirits.

How native yeasts may influence the chemical profile of the Brazilian spirit, cachaça?

Cachaça is the typical Brazilian spirit, obtained by distillation of fermented sugarcane must, whose production is closely related to regional heritage and geographical traits. In this work, we investigate the influence of different autochthonous yeast species, in comparison to other commercial strains, on the chemical profile of cachaça. Fermentations were performed with four different wild species, a mixed starter culture with native yeasts, and two commercial strains. Procedures were carried out simulating traditional practices, the distillates analyzed by gas chromatography, and data analyzed by multivariate statistics. Results show that the overgrowth of some non-Saccharomyces during fermentation can lead to higher concentration of contaminant compounds in the distillate. However, those microorganisms do not impress negative traits when working in cluster association, and may indeed contribute to the distinctive chemical quality and flavor of cachaça. Spontaneous fermentation are still the traditional method used for the production of cachaça, and our results indeed suggest that higher diversity, and evened fermentative environments, enable yeasts to act as a complex cluster and imprint a distinctive, quality chemical profile to the distillate. Finally, this study may help to understand the role of the native microbiota and its influence on cachaças chemical and sensory profiles, besides demonstrating the importance of adopting insightful handling practices and strict control of technical guidelines.

Volatile and maturation congeners in Cachaça aged in new, second-use and extensive fill barrels

Methodology: Sorghum (Sorghum bicolor L.) and okra (Abelmoschus esculentus L.) were grown in sterilized and fertilized loamy sand, with two phosphorus supply levels: 50 mg P (P1) or 100 mg P (P2) per kg dry soil. Plants were either inoculated with R. irregularis (+M) or left non-inoculated (-M). After four weeks of growth, plants were exposed to water stress, i.e. the soil was irrigated either to 15% (w/w) water content for the well-watered (+W), or 7% (w/w) for the water stress treatment (-W).Methodology & Data: The intra-seasonal Soil Water Management Program Economic model (SWAMP-ECON), which is a simulation-optimization model, was developed to deal with the main objective of the research. The simulation part comprises the Soil Water Management Program (SWAMP) crop growth model which was supplemented with economic module to quantify the economic impacts of alternative irrigation schedule options while the optimization section uses special evolutionary algorithms (EA) to find optimized irrigation scheduling for a field crop. State-contingent approach was followed to model production uncertainty in SWAMP-ECON.