RESUMO
Alternative solvents are being tested as green solvents to replace the traditional organic solvents used in both academy and industry. Some of these are already available, such as ethyl lactate, cyrene, limonene, glycerol, and others. This alternative explores eco-friendly processes for extracting secondary metabolites from nature, thus increasing the number of unconventional extraction methods with lower environmental impact over conventional methods. In this context, the Peruvian Ambrosia arborescens was our model while exploring a microwave-assisted extraction (MAE) approach over maceration. The objective of this study was to perform a phytochemical study including UHPLC-ESI-MS/MS and the antioxidant activity of Ambrosia arborescens, using sustainable strategies by mixing both microwaves and ethyl lactate as a green solvent. The results showed that ethyl lactate/MAE (15.07%) achieved a higher extraction yield than methanol/maceration (12.6%). In the case of the isolation of psilostachyin, it was similar to ethyl lactate (0.44%) when compared to methanol (0.40%). Regarding UHPLC-ESI-MS/MS studies, the results were similar. Twenty-eight compounds were identified in the ethyl lactate/MAE and methanol/maceration extracts, except for the tentative identification of two additional amino acids (peaks 4 and 6) in the MeOH extract. In relation to the antioxidant assay, the activity of the ethyl lactate extract was a little higher than the methanol extract in terms of ORAC (715.38 ± 3.2) and DPPH (263.04 ± 2.8). This study on A. arborescens demonstrated that the unconventional techniques, such as MAE related to ethyl lactate, could replace maceration/MeOH for the extraction and isolation of metabolites from diverse sources. This finding showed the potential of unconventional methods with green solvents to provide eco-friendly methods based on green chemistry.
RESUMO
The effects of Lactobacillus plantarum UFLA CH3, Pediococcus acidilactici UFLA BFFCX 27.1, and Torulaspora delbrueckii UFLA FFT2.4 inoculation on the volatile compound profile of fermentation of Cucumeropsis mannii cotyledons were investigated. Different microbial associations were used as starters. All associations displayed the ability to ferment the cotyledons as judged by lowering the pH from 6.4 to 4.4-5 within 24h and increasing organic acids such as lactate and acetate. The population of lactic acid bacteria (LAB) and yeasts increased during fermentation. In the fermentation performed without inoculation (control), the LAB and yeast populations were lower than those in inoculated assays at the beginning, but they reached similar populations after 48 h. The Enterobacteriaceae population decreased during the fermentation, and they were not detected at 48 h in the L. plantarum UFLA CH3 and P. acidilactici UFLA BFFCX 27.1 (LP+PA) and L. plantarum UFLA CH3, P. acidilactici UFLA BFFCX 27.1, and T. delbrueckii UFLA FFT2.4 (LP+PA+TD) samples. The assays inoculated with the yeast T. delbrueckii UFLA FFT2.4 exhibited the majority of volatile compounds (13 compounds) characterized by pleasant notes. The LP+PA+TD association seemed to be appropriate to ferment C. mannii cotyledons. It was able to control the Enterobacteriaceae population, and achieved high concentrations of esters and low concentrations of aldehydes and ketones.
Assuntos
Cotilédone/metabolismo , Cucurbitaceae/metabolismo , Fermentação , Microbiologia Industrial , Enterobacteriaceae/fisiologia , Técnicas In Vitro , Lactobacillus plantarum/metabolismo , Pediococcus/metabolismo , Pediococcus/fisiologia , Torulaspora/metabolismo , Torulaspora/fisiologia , Leveduras/crescimento & desenvolvimentoRESUMO
The aim of this work was to study the microbial communities and volatile compounds profile of different fermentations: using four different cocoa hybrids and adding Saccharomyces cerevisiae UFLA CA11 as starter culture. Each hybrid showed particular characteristics: size, peel, seed and pulp. The temperature of the cocoa mass increased during fermentations (24°C to 47°C). The hybrid FA13 inoculated with S. cerevisiae showed the lowest temperatures (26 to 37°C). The pulp's compositions were different between the hybrids, mainly regarding citric acid (0.5 to 3.2g/kg). The carbohydrates were more rapidly (60h) metabolized in inoculated fermentations than in spontaneous fermentations (84h). Thirty-nine volatile compounds were identified by GC-FID for all fermentation processes. Esters (14 compounds) and alcohols (12) were the most important groups. Yeast communities were similar among the different processes while bacterial communities were dependent on the hybrid and process. The inoculation accelerated the fermentation and the hybrid characteristics influenced on the fermentation requiring particular management.
RESUMO
The objective of the work was to evaluate the effect of malolactic fermentation (MLF) on the composition of Cabernet Franc, Cabernet Sauvignon and Isabella wines, elaborated on a small scale during the 1995 vintage. Eighteen variables were evaluated before and after MLF. The results showed that MLF degraded the malic acid, decreased the total acidity, the dry extract, the reduced dry extract and color intensity and increased the pH, the volatile acidity, the alcohol in weight/reduced dry extract ratio and the A420/A520 ratio. Among the volatile compounds it was observed the formation of ethyl lactate and acetoin.
O objetivo do trabalho foi avaliar o efeito da fermentação maloláctica (FML) na composição dos vinhos Cabernet Franc, Cabernet Sauvignon e Isabel, elaborados em pequena escala na safra de 1995. Dezoito variáveis foram avaliadas antes e após a FML. Os resultados mostraram que houve degradação do ácido málico; diminuição da acidez total, do extrato seco, do extrato seco reduzido e da intensidade de cor; e aumento do pH, da acidez volátil, da relação álcool em peso/extrato seco reduzido e da relação I420/I520. Entre os compostos voláteis, verificou-se a formação de lactato de etila e da acetoína.
RESUMO
The objective of the work was to evaluate the effect of malolactic fermentation (MLF) on the composition of Cabernet Franc, Cabernet Sauvignon and Isabella wines, elaborated on a small scale during the 1995 vintage. Eighteen variables were evaluated before and after MLF. The results showed that MLF degraded the malic acid, decreased the total acidity, the dry extract, the reduced dry extract and color intensity and increased the pH, the volatile acidity, the alcohol in weight/reduced dry extract ratio and the A420/A520 ratio. Among the volatile compounds it was observed the formation of ethyl lactate and acetoin.
O objetivo do trabalho foi avaliar o efeito da fermentação maloláctica (FML) na composição dos vinhos Cabernet Franc, Cabernet Sauvignon e Isabel, elaborados em pequena escala na safra de 1995. Dezoito variáveis foram avaliadas antes e após a FML. Os resultados mostraram que houve degradação do ácido málico; diminuição da acidez total, do extrato seco, do extrato seco reduzido e da intensidade de cor; e aumento do pH, da acidez volátil, da relação álcool em peso/extrato seco reduzido e da relação I420/I520. Entre os compostos voláteis, verificou-se a formação de lactato de etila e da acetoína.