Suchergebnisse

Twenty-eight commercial herb liqueurs, elaborated by maceration of aromatic and medicinal plants in grape marc distillate, were analysed. Thirty-two volatile compounds were identified and quantified by gas chromatographymass spectrometry, whereas seven phenols were determined by high-performance liquid chromatography with UV detection. All compounds showed significant differences among the samples analysed as consequence of the initial composition of the distillate and the plants and spices used in the liqueur elaboration. Of the 32 volatile compounds identified, 18 were considered to be impact odorants (odour activity value ?1) and these were classified into six odorant series. Spice, fruity and floral were the series that contributed the most to the aroma profile of the evaluated liqueurs. A first principal components analysis (PCA) was performed on the concentration of the seven phenols and these accounted for 75.37% of the total variance and a second PCA was performed on the concentration of the 18 impact odorants and these accounted for 60.96% of the total variance; allowing for the classification of the liqueur samples into three different groups. ; We are grateful to the Spanish Ministry of Economy and Competitiveness for the financial support of this work (project CTQ201571436-C2-1-R), which has partial financial support from the FEDER funds of the European Union. José Manuel Salgado was supported by the grant SFRH/BPD/84440/2012 from Fundação para a Ciência e Tecnologia - FCT, ...

Two phase olive mill waste (TPOMW) is presently the major waste produced by the olive mill industry. This waste has potential to be used as substrate for solid state fermentation (SSF) despite of its high concentration of phenolic compounds and low nitrogen content. In this work, it is demonstrated that mixtures of TPOMW with winery wastes support the production of lipase by Aspergillus spp. By agar plate screening, Aspergillus niger MUM 03.58, Aspergillus ibericus MUM 03.49 and Aspergillus uvarum MUM 08.01 were chosen for lipase production by SSF. Plackett-Burman experimental design was employed to evaluate the effect of substrate composition and time on lipase production. The highest amounts of lipase were produced by A. ibericus on a mixture of TPOMW, urea and exhausted grape mark (EGM). Urea was found to be the most influent factor for the lipase production. Further optimization of lipase production by A. ibericus using a full factorial design (32) conducted to optimal conditions of substrate composition (0.073 g urea/g and 25% of EGM) achieving 18.67 U/g of lipolytic activity. ; Jose Manuel Salgado is grateful for Postdoctoral fellowship (EX-2010-0402) of Education Ministry of Spanish Government. Luis Abrunhosa was supported by the grant SFRH/BPD/43922/2008 from Fundacao para a Ciencia e Tecnologia-FCT, Portugal. Authors thank Fundacao para a Ciencia e a Tecnologia (FCT) for financial support through the project FCT ...

Phenolic compounds (benzoic and cinnamic acid derivatives) were determined by high-performance liquid chromatography with multiple wavelength detector (HPLC--MWD) in grape marc distillates aged in Quercus petraea, Quercus robur and Quercus alba wooden barrels. In addition to colour indices and evaluable polyphenols, all samples were described by sensorial analysis. There were significant differences in the mean concentrations of the majority of phenolic compounds among the samples. Gallic and benzoic acids were the most abundant and samples aged in Q. robur from Galicia (NW of Spain) had the highest concentration of most of the determined phenols. Grape marc distillates aged in Q. robur obtained the highest values of all sensorial attributes, whereas samples aged in Q. petraea and Q. alba obtained similar scores. Principal component analysis accounted for 88.32 % of total variance, showing a good separation of aged distillates in terms of phenolic compounds and colour characteristics, according to the species and origin of the oak wood used in the ageing process. ; We are grateful for the financial support of this work to the Spanish Ministry of Science and Innovation (project CTQ2011-28967), and partial financial support from the FEDER funds of the European Union and to the Regulatory Board of Geographical Names of the Traditional Galician Spirits and Liqueurs for providing the samples. Jose Manuel Salgado is grateful for postdoctoral fellowship (EX-2010-0402) of Education Ministry of Spanish ...

Wastes from olive oil and wine industries (as exhausted grape marc, vineshoot trimmings, two-phase olive mill waste, vinasses, and olive mill wastewater) were evaluated for lignocellulolytic enzyme production (as endocellulases, endoxylanases, and feruloyl esterases) by solid-state fermentation (SSF) with Aspergillus niger, Aspergillus ibericus, and Aspergillus uvarum. To study the effect of different solid medium composition and time in enzyme production, a PlackettBurman experimental design was used. Variables that had a higher positive effect in lignocellulolytic enzyme production were urea, time, and exhausted grape marc. The maximum values of enzymatic activity per unit of substrate dry mass were found with A. niger for feruloyl esterase. Enzymatic extracts from SSF with A. niger achieved maximum feruloyl esterase activity (89.53 U/g) and endoxylanase activity (3.06 U/g) and with A. uvarum for endocellulase activity (6.77 U/g). The enzyme cocktails obtained in the SSF extracts may have applications in biorefinery industries. ; Jose Manuel Salgado is grateful for the postdoctoral fellowship (EX-2010-0402) of the Education Ministry of Spanish Government. Luis Abrunhosa was supported by the grant SFRH/BPD/43922/2008 from Fundacao para a Ciencia e Tecnologia-FCT, ...

Background and Aims The ageing process, in wooden barrels, is used to improve the sensory quality of wines and distillates. This process, however, is costly, often leading to an alternative strategy of using wood fragments. The main aim of this work was to evaluate the influence of size, toast level and origin of the oak fragments on the composition of grape marc distillates. Methods and Results The accelerated ageing process of grape marc distillate was optimised with a BoxBenhken experimental design. Five dependent variables were evaluated: the concentration of vanillin, whiskey lactone and phenolic substances, the antioxidant activity and the colour parameters to determine the influence of the independent variables: concentration of oak fragments, proportion of ethanol in Galician grape marc distillate (Orujo) and the time of maceration. The concentration of oak fragments was the variable with the greatest effect on the dependent variables evaluated, except for whiskey lactone. The optimal conditions obtained were applied in 11 experimental accelerated ageing processes to study the influence of size, toast level and origin of the oak fragments on the parameters previously mentioned. Conclusions The best results were obtained with the smaller fragment size (granular) from Quercus petraea with medium toast level. The contact time did not significantly influence the parameters evaluated. Significance of the Study This study, performed at a micro-scale, determined the optimum conditions for greater extraction of compounds from oak with beneficial characteristics: volatile compounds with positive notes, vanillin and whiskey lactone, and the phenolic substances with antioxidant properties. This option allows producers to reduce considerably the cost of the process. ; We are gratefulto the Spanish Ministry of Economy and Competitiveness for the financial support of this work (project CTQ2015-71436-C2-1-R), which has partial financial support from the FEDER funds of the European Union and to Laffort for providing the ...

BACKGROUND Herbal liqueurs are alcoholic beverages produced by the maceration or distillation of aromatic and medicinal plants in alcohol, and are also highly valued for their medicinal properties. The process conditions, as well as the number and quantity of the plants employed, will have a great influence on the quality of the liqueur obtained. The aim of this research was to optimize these important variables. RESULTS A BoxBenhken experimental design was used to evaluate the independent variables: alcohol content, amount of plant and time during the experimental maceration of plants in grape marc distillate. Four plants were assessed, with the main compound of each plant representing the dependent variable evaluated with respect to following the evolution of the maceration process. Bisabolol oxide A in Matricaria recutita L., linalool in Coriander sativum L. and eucalyptol in Eucalyptus globulus Labill. were quantified using a gas chromatography-flame ionization detector. Glycyrrhizic acid in Glycyrrhiza glabra L was determined using a high-performance liquid chromatography-diode array detector. Other dependent variables were also evaluated: total phenolic content, color parameters and consumer preference (i.e. appearance). CONCLUSION The experimental designs allowed the selection of the optimal maceration conditions for each parameter, including the preference score of consumers: 70% (v/v) of ethanol, 40 g L1 plant concentration and a maceration process of 3 weeks. ; Spanish Ministry of Economy and Competitiveness - (project CTQ2015-71436-C2-1-R) ; FEDER funds of the European Union ; Fundação para a Ciência e Tecnologia a (FCT) - grant ...

In situ extractive fermentation was used to produce 4-vinyl derivatives from hydroxycinnamic acids extracted from corn cobs by recombinant Escherichia coli cells expressing Lactobacillus plantarum phenolic acid descarboxylase (PAD) gene. This microorganism mainly produced 4-vinylphenol (4VP) from p-coumaric acid (p-CA). In a first study, we observed that concentrations of 4VP higher than 1 g/L had a negative impact on descarboxylation of p-CA to 4VP by recombinant E.coli cells. Because of this, and in order to improve the downstream process, a two-phase aqueous-organic solvent system was developed. The results of the extractive fermentation indicated that it was possible to use hydrolyzates as aqueous phase to bioproduce 4VP, and recover simultaneously the product in the organic phase containing hexane. The detoxification of pre-treated corn cob alkaline hydrolyzate improved 4VP production up to 1003.5 mg/L after 24 h fermentation (QP = 41.813 mg/L·h). Additionally, preliminary experiments using cells immobilized in calcium alginate showed to be a good system for the biotransform of p-CA to 4VP in extractive fermentation, although the process hindered partially the recovery of 4VP in the organic phase. ; We are grateful to the Spanish Ministry of Science and Innovation for the financial support of this work (CTQ2011-28967 and AGL2011-22745 projects), which has partial financial support from the FEDER funds of the European Union. J.M.S. is grateful for Postdoctoral fellowship (SFRH / BPD / 84440 / 2012) of Fundacao para a Ciencia e Tecnologia - ...