RESUMO
This article contains data obtained by following the evolution of minor volatile compounds throughout 32 weeks of 100% Agave Silver tequila maturation in new French oak barrels under real cellar conditions. Barrels were made with the same cooperage methods in four French regions. Tequila samples were obtained every 2 weeks; volatile compounds were extracted and analyzed by GC-MS. Volatile compounds were identified and relatively quantified in % of Area. Obtained data are presented in three datasets: Identified compounds, quantification according to barrel origin, and quantification according to maturation time. General Discriminant Analysis of the quantification data sets are also shown. Interpretation of the data and discussion can be found in "Evolution of volatile compounds during the maturation process of Silver tequila in new French oak barrels" Martín-del-Campo, López-Ramírez and Estarrón-Espinosa [1].
RESUMO
This study examined the impact of emulsifier type on the physicochemical characteristics and antifungal capacity of oregano oil-in-water emulsions: Tween 80, hydroxylated soy lecithin, and gum arabic. GC/MS analysis showed that the major components of the Lippia graveolens essential oils were thymol (31.7%), p-cymene (18.7%), and carvacrol (14.6%). The oil-in-water emulsions were made using ultrasonic technology in which thymol and carvacrol quantities were 12.26-13.67 g/L and 5.6-6.2 g/L, respectively. The droplet size of the emulsions followed the next descendent order: gum arabic > lecithin > T80. The zeta potential of the emulsions favored the stability against coalescence. Finally, the antifungal activity of the emulsions was evaluated, in which, 30 µL/mL of gum arabic or hydroxylated soy lecithin emulsions inhibited the growth of Candida albicans. The result suggests that Mexican oregano essential oil emulsions can be used as an antifungal against of C. albicans.
RESUMO
Knowledge of physiological behavior of indigenous tequila yeast used in fermentation process is still limited. Yeasts have significant impact on the productivity fermentation process as well as the sensorial characteristics of the alcoholic beverage. For these reasons a better knowledge of the physiological and metabolic features of these yeasts is required. The effects of dilution rate, nitrogen and phosphorus source addition and micro-aeration on growth, fermentation and synthesis of volatile compounds of two native Saccharomyces cerevisiae strains, cultured in continuous fed with Agave tequilana juice were studied. For S1 and S2 strains, maximal concentrations of biomass, ethanol, consumed sugars, alcohols and esters were obtained at 0.04 h⻹. Those concentrations quickly decreased as D increased. For S. cerevisiae S1 cultures (at D=0.08 h⻹) supplemented with ammonium phosphate (AP) from 1 to 4 g/L, concentrations of residual sugars decreased from 29.42 to 17.60 g/L and ethanol increased from 29.63 to 40.08 g/L, respectively. The S1 culture supplemented with AP was then micro-aerated from 0 to 0.02 vvm, improving all the kinetics parameters: biomass, ethanol and glycerol concentrations increased from 5.66, 40.08 and 3.11 g/L to 8.04, 45.91 and 4.88 g/L; residual sugars decreased from 17.67 g/L to 4.48 g/L; and rates of productions of biomass and ethanol, and consumption of sugars increased from 0.45, 3.21 and 7.33 g/L·h to 0.64, 3.67 and 8.38 g/L·h, respectively. Concentrations of volatile compounds were also influenced by the micro-aeration rate. Ester and alcohol concentrations were higher, in none aerated and in aerated cultures respectively.
Assuntos
Agave/metabolismo , Bebidas Alcoólicas , Fermentação , Saccharomyces cerevisiae/metabolismo , Álcoois/metabolismo , Amônia/metabolismo , Biomassa , Metabolismo dos Carboidratos , Etanol/metabolismo , Manipulação de Alimentos/métodos , Glicerol/metabolismo , Nitrogênio/metabolismo , Oxigênio/metabolismo , Fosfatos/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Compostos Orgânicos Voláteis/metabolismoRESUMO
AIMS: To study how the antimicrobial and antioxidant activities of Lippia graveolens essential oils with different composition are affected after the microencapsulation process with beta-cyclodextrin (beta CD). METHODS AND RESULTS: Three Mexican oregano essential oils (EOs) with different carvacrol/thymol/p-cymene ratios (38 : 3 : 32, 23 : 2 : 42, 7 : 19 : 35) were used in this study. Microencapsulation was carried out by spray-drying. Antimicrobial activities were measured as MBC (minimal bactericidal concentration) using 0.05%/0.10%/0.20% (w/v) dilutions of EOs against Escherichia coli ATCC 11229, Pseudomonas aeruginosa ATCC 9027 and Staphylococcus aureus ATCC 6538. Antioxidant activities were determined by the 2,2'-diphenyl-1-picrylhydrazil (DPPH) method. EOs showed antimicrobial and antioxidant activity, but microencapsulation preserved the antimicrobial activity in all cases and increased the antioxidant activity from four- to eightfold. CONCLUSIONS: Although the Lippia essential oils were from the same species, their composition affects the biological activities before and after the microencapsulation process, as well as encapsulation efficiency. Our study supports the fact that microencapsulation of EOs in beta-cyclodextrin preserves the antimicrobial activity, improves the antioxidant activity and acts as a protection for EOs main compounds. SIGNIFICANCE AND IMPACT OF THE STUDY: Microencapsulation affects positively EOs main compounds, improves antioxidant activity and retains antimicrobial activity, enhancing the quality of the oils.