Reliability of a Screening Method Using Antibiotic Disks to Detect Carbapenemases in Glucose-Nonfermenting Gram-Negative Microorganisms From Clinical Samples of a Regional Hospital in Southeastern Spain.

BACKGROUND: Infections by glucose-nonfermenting gram-negative bacilli (NFGNB) pose a major public health problem due to multiresistance to beta-lactam antibiotics, especially plasmid-borne carbapenemases. Their detection by microbiology laboratories is challenging, and there is a need for easy-to-use and reliable diagnostic techniques. Our objective was to evaluate an in-house screening method to presumptively detect carbapenemases in NFGNB in a simple and clinically useful manner. METHODS: The study included 175 NFGNB isolates from urinary, respiratory, and rectal samples. In a triple assay, isolates were incubated at 37°C for 24 h on three solid-culture media: MacConkey II Agar, 5% Sheep Blood Columbia Agar and Mueller Hinton II Agar; meropenem (MEM) and cefepime (FEP) disks were employed for screening. Studies were then performed on the inhibition halo diameter, scanning effects, and the appearance of mutant colonies, which were compared with those observed using the colorimetric Neo-Rapid CARB Kit and immunochromatography (NG5-Test Carba and K-Set for OXA-23). Receiver operating characteristic curves were constructed for these data. RESULTS: Carbapenemases were expressed by 79/175 (45.1%): 19 Pseudomonas aeruginosa and 60 Acinetobacter baumannii. Optimal inhibition halo diameter cutoffs to detect this resistance on 5% sheep blood agar were as follows: 6 mm (MEM) and 6.5 mm (FEP) for P. aeruginosa (in the absence of scanning effects and mutations) and 10.5 mm (MEM) and 16 mm (FEP) for A. baumannii (even in the presence of scanning effects). CONCLUSION: The combined utilization of MEM and FEP antibiotic disks in 5% sheep blood agar, measuring their inhibition haloes, offers an effective method to predict the presence of carbapenemases as resistance mechanism in P. aeruginosa and A. baumannii.

Concerning the presumptive identification of Candida kefyr on Uriselect™4 agar / Sobre la identificación presuntiva de Candida kefyr en agar Uriselect™4

Introduction. Non-albicans Candida species, such as Candida kefyr, are emerging pathogens. Chromogenic media are highly useful for the diagnosis of urinary tract infections (UTIs). The aim was to describe the behavior of this specie on a non-specific chromogenic medium. Material and methods. A retrospective study of cases of candiduria detected in the Microbiology laboratory of the Virgen de las Nieves Hospital in Granada (Spain) between 2016 and 2021 (N=2,130). Urine samples were quantitatively seeded on non-selective UriSelect™4 chromogenic agar. Results. Between 2016 and 2021, C. kefyr was the seventh most frequent Candida species responsible for candiduria in our setting (n=15). The macroscopic appearance of C. kefyr colonies, punctiform and bluish, allowed the direct identification of these microorganisms. Conclusions. This study provides the first description of the specific behavior of C. kefyr on UriSelect™4 agar, which differentiates it from other Candida species based on its enzymatic characteristics. (AU)

Introducción. Las especies de Candida no-albicans, como Candida kefyr, son patógenos emergentes. Los medios cromogénicos son muy útiles para el diagnóstico de infecciones del tracto urinario (ITU). El objetivo era describir el comportamiento de esta especie en un medio cromogénico no específico. Material y métodos. Estudio retrospectivo de casos de candiduria detectados en el laboratorio de Microbiología del Hospital Virgen de las Nieves de Granada (España) entre 2016 y 2021 (N=2.130). Las muestras de orina se sembraron cuantitativamente en agar cromogénico no selectivo Uri Select™4. Resultados. C. kefyr fue la séptima especie de Candida responsables de la candiduria en nuestro medio (n = 15). El aspecto macroscópico de las colonias de C. kefyr, puntiformes y azuladas, permitió su identificación presuntiva directamente. Conclusiones. Este estudio proporciona la primera descripción del comportamiento específico de C. kefyr en agar Uri Select™4, que lo diferencia de otras especies de Candida en función de sus características enzimáticas. (AU)

Microbial characterization of Sichuan Baoning vinegar: lactic acid bacteria, acetic acid bacteria and yeasts.

Sichuan Baoning vinegar, a typical representative of Sichuan bran vinegar, is a famous traditional fermented food made from cereals in China. At present, there are few studies on microbial characterization of culturable microorganisms in solid-state fermentation of Sichuan bran vinegar. To comprehensively understand the diversity of lactic acid bacteria, acetic acid bacteria and yeasts, which play an important role in the fermentation of Sichuan bran vinegar, traditional culture-dependent methods combined with morphological, biochemical, and molecular identification techniques were employed to screen and identify these isolates. A total of 34 lactic acid bacteria isolates, 39 acetic acid bacteria isolates, and 48 yeast isolates were obtained. Lactic acid bacteria were dominated by Enterococcus durans, Leuconostoc citreum, Lactococcus lactis, and Lactiplantibacillus plantarum, respectively. Latilactobacillus sakei was the first discovery in cereal vinegar. Acetic acid bacteria were mainly Acetobacter pomorum and A. pasteurianus. The dominant yeast isolates were Saccharomyces cerevisiae, in addition to four non-Saccharomyces yeasts. DNA fingerprinting revealed that isolates belonging to the same species exhibited intraspecific diversity, and there were differences between phenotypic and genotypic classification results. This study further enriches studies on cereal vinegar and lays a foundation for the development of vinegar starters.

Preliminary reading of antibiogram by microdilution for clinical isolates in urine culture.

PURPOSE: We evaluated a modification of automated antibiograms in urine cultures designed to facilitate the early interpretation of minimum inhibitory concentrations (MICs) and accelerate the targeted treatment of urinary tract infections (UTIs), METHODS: A prospective study was conducted of 309 isolates (219 Enterobacteriaceae, 75 Enterococcus spp., and 15 non-fermenting Gram-negative bacilli (NFGNB), and a retrospective study of 9 carbapenemase-producing clinical isolates from urine cultures. Colonies grown on conventional isolation plates were inoculated in MicroScan Walkaway system panels and incubated for 7 h, using a MicroScan AutoScan-4 plate reader for preliminary MIC determination by turbidimetry. Resulting antibiograms were compared with definitive antibiograms obtained after incubation for 17 h. RESULTS: Preliminary and definitive readings were concordant for 86.7% of Gram-positive cocci isolates (65/75), 61.6% of Enterobacteriaceae (135/219), and 53.3% of NFGNB. The agreement rate was greater than 90% for most antimicrobials against Gram-positive cocci (94.7% or more) and Enterobacteriaceae, (97.2% or more for 10 of 17 antibiotics) except with nitrofurantoin (89%). The agreement rate was 86.7% or more for most antibiotics against NFGNB apart from piperacillin/tazobactam, aztreonam, amikacin, and ciprofloxacin. Gram-negative bacilli showed the highest differences in MIC values between preliminary and definitive readings. CONCLUSIONS: A preliminary antibiogram reading may be useful in urine cultures to reduce the delay before targeted antibiotherapy, especially against Enterobacteriaceae and Gram-positive cocci, but not in cases of carbapenemase-producing NFGNB. Further local studies are warranted to evaluate the usefulness of this approach in relation to resistance rates.

Antibiotic resistances of Pseudomonas aeruginosa and Acinetobacter baumannii in urine cultures: experience in a hospital of Southeast Spain.

The objectives of this study were to perform a systematic review of publications between 2010 and 2021 on the antibiotic resistance of Pseudomonas aeruginosa and Acinetobacter baumannii from urinary tract infections and to analyze changes over time in hospital urine cultures from 2016 through 2021. The literature was searched, and a retrospective cross-sectional descriptive study was performed in the hospital. Out of 21 838 positive urine cultures, 3.86% were due to P. aeruginosa and 0.44% were due to A. baumannii. For P. aeruginosa, lower resistance rates were observed to virtually all tested antibiotics than were obtained in the systematic review, and the present series of hospital samples showed an in vitro resistance rate <10% to ceftazidime, cefepime, meropenem, piperacillin-tazobactam, amikacin, tobramycin, and colistin. For A. baumannii, the resistance rates to almost all antibiotics were higher in the present series than in the systematic review, being lowest to colistin (10%). Both microorganisms show reduced in vitro susceptibility to some antibiotics during the years of the COVID-19 pandemic in comparison to previous years. In our setting, both piperacillin-tazobactam and meropenem can be recommended for the empirical treatment of UTIs by P. aeruginosa, whereas only colistin can be recommended for UTIs by A. baumannii.

Comparative study on the use of seasoned or unseasoned casks made of wood from different origins for the ageing of Sherry vinegar.

BACKGROUND: In the present study, the ageing process of Sherry vinegar in used (seasoned) or new casks made of chestnut, American oak, Spanish oak or French oak wood has been investigated, considering that no research has investigated whether this seasoning has a definite influence on the final composition of the aged beverage. The polyphenolic and volatile contents of the aged vinegars were determined and their sensory properties were evaluated. Different statistical tools were applied to the data collected. RESULTS: With respect to polyphenolic contents, ageing time was the most influential factor, followed by the seasoned-cask factor. The type of wood was only significant for gallic acid, p-hydroxybenzoic acid, methylfurfural, ethyl gallate, ferulic acid, coniferyl aldehyde and sinapaldehyde. Principal component analysis according to polyphenols did not allow the samples to be differentiated, whereas cluster analysis revealed a slight grouping trend according to ageing time and seasoning of the wood. In relation to volatile compounds, variance analysis revealed that, again, ageing time and cask-seasoning were the most significant factors, with the samples clustering according to these two parameters. Following the sensory study, a clear difference between seasoned and new cask vinegars could be established as a result of the high scores in olfactory quality obtained for those vinegars aged in new casks. This was probably because of an excess of the descriptor 'ethyl acetate' exhibited by seasoned-cask Sherry vinegars. CONCLUSION: The previous seasoning of the casks together with the ageing time conditioned the composition of the vinegars aged in casks of different botanical origin, which translated into differences at a sensory level. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Genetic Characterization of Extensively Drug-Resistant Shigella sonnei Infections, Spain, 2021-2022.

In 2022, the United Kingdom reported an increase in drug resistance in Shigella sonnei isolates. We report 33 cases in Spain genetically related to the UK cases and 4 cases with similar antimicrobial resistance profiles infected with genetically distant strains. Our results suggest circulation of multiple genetic clusters of multidrug-resistant S. sonnei in Spain.

Method development of stir bar sportive extraction coupled with thermal desorption-gas chromatography-mass spectrometry for the analysis of phthalates in Peruvian pisco.

In this work, for the first time, a stir bar sorptive extraction (SBSE) coupled with thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was developed and validated for the determination of seven phthalates in Peruvian pisco. The phthalate compounds considered were dimethyl phthalate (DMP), diethyl phthalate (DEP), bis(2-ethylhexyl) hexahydrophthalate (BEHP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di-isodecyl phthalate (DIDP) and di-isobutyl phthalate (DIBP). The best overall analytical conditions obtained from the optimization were as follow: extraction time of 120 min, size of polydimethylsiloxane (PDMS) twister (20 mm length x 1 mm thickness), NaCl content (20 %) and sample volume (40 mL). The in-house validation of SBSE/TD-GC-MS method was performed taking into account the ISO/IEC 17,025 requirements and EURACHEM/CITAC guideline. Under optimal conditions, very low limits of detection of 1.3-0.21 µg L-1 were obtained. Furthermore, the limits of quantification ranged from 4.2-70 µg L-1, and the correlation coefficients were found to be ≥ 0.991. The method was precise, with relative standard deviations (RSD, %) for inter twister repeatability and the inter day repeatability precisions from 1.1 to 11 and from 6.2 to 15.9, respectively. The pisco samples were analysed with recoveries between 91-124.4%, and DBP, BEHP, and BBP were the most commonly found compounds in the samples. The optimized methodology was also evaluated in terms of green character, and it obtained almost the best AGREE score when it was compared with other previous methods for the analysis of phthalates in alcoholic beverages. Therefore, the SBSE/TD-GC-MS method has proved to be suitable for routine practice because it is simple, less laborious, economical, precise, accurate and green, and it would be applicable for pisco safety regulations.

Development and Characterization of Probiotic Beers with Saccharomyces boulardii as an Alternative to Conventional Brewer's Yeast.

The development of new non-dairy probiotic foods is interesting, given lactose intolerance, milk allergies, and the growing trend of vegetarianism. In this paper, beer has been used as a probiotic delivery matrix, using Saccharomyces boulardii as an alternative to conventional brewer's yeast. The strain was able to grow in worts prepared with hops containing different alpha-acid concentrations, attaining in all cases a final cell concentration above 1·108 cells mL-1. Some differences were found in the physicochemical parameters of beers brewed with S. boulardii compared to those brewed with a standard brewer's yeast. Probiotic beers turned out to be less cloudy, which could help with a possible filtering step; less alcoholic in some cases; a healthier alternative; and with a slightly lower pH, interesting for the reduction of spoilage risk. Thirty volatile compounds were determined in the samples, and, in general, the beers brewed with the probiotic yeast presented significantly higher concentrations for the majority of the studied volatile compounds. In addition, multivariate statistical analysis was successfully performed to differentiate the beers obtained in terms of their volatile composition. Probiotic and standard beers were also subjected to sensory analysis, and they presented similar results in their overall impression.

Shigelosis atendidas en el servicio de urgencias de un hospital regional del sudeste de España: Desde su presencia a la multirresistencia / Shigellosis attended in the emergency department of a regional hospital in southeastern Spain: from their presence to multiresistance

Introduction. In the bacterial etiology of severe acute infectious diarrhea, except that caused by Clostridioides difficile, most of them have an invasive character and antibiotic treatment will be necessary in specific situations. Shigella is a classic pathogen, in which it is crucial to know the sensitivity to different classic and alternative antimicrobials. The objective of this work was to analyze the presence of shigellosis and the rate of antibiotic resistance.Methods. A descriptive-retrospective study of the reports of shigellosis of stool cultures issued between January 2016 and April 2022 was conducted.Results. A total of 34 episodes (16 -47.1%- by Shigella sonnei) were observed, as of 2018. There were only 2 pediatric cases. The overall resistance rate to azithromycin, trimethoprim-sulfamethoxazole and ciprofloxacin was 52.9%, 64.7% and 44.1%, respectively. 26.5% were resistant to the 3 groups of antibiotics. There was a higher rate of resistance for S. sonnei. The emergence of resistance to cephalosporins in recent years stands out. Episodes of multidrug-resistant shigellosis were detected between 2020 (1 by S. flexneri) and 2022 (4 by S. sonnei).Conclusions. The episodes of shigellosis are emerging in our environment with a higher rate of multi-resistance. In this context, current empirical treatments for acute enteroinvasive enteritis are at risk of failure, if necessary.

Introducción: En la etiología bacteriana de la diarrea infecciosa aguda grave, exceptuando la causada por Clostridioides difficile, la mayor parte presentan un carácter invasor y el tratamiento antibiótico será preciso en situaciones concretas. Shigella es un patógeno clásico, en el que es crucial conocer la sensibilidad a distintos antimicrobianos clásicos y alternativos. El objetivo de este trabajo fue analizar la presencia de shigelosis y la tasa de resistencia a los antibióticos. Métodos: Se realizó un estudio descriptivo-retrospectivo de los informes de shigelosis de los coprocultivos emitidos entre enero de 2016 y abril de 2022. Resultados: Se observó un total de 34 episodios (16-47,1%- por Shigella sonnei), a partir del 2018. Sólo hubo 2 casos pediátricos. La tasa de resistencia global a azitromicina, trimetoprim-sulfametoxazol y ciprofloxacino fue de 52,9%, 64,7% y 44,1%, respectivamente. El 26,5% fueron resistentes a los 3 grupos de antibióticos. Hubo mayor tasa de resistencia por S. sonnei. Destaca la aparición de resistencia a cefalosporinas en los últimos años. Los episodios de shigelosis multirresistente se detectaron entre 2020 (1 por S. flexneri) y 2022 (4 por S. sonnei). Conclusiones: Los episodios de shigelosis importada están emergiendo en nuestro medio con una mayor tasa de multirresistencia. En este contexto, los tratamientos empíricos actuales para las enteritis agudas enteroinvasivas corren el riesgo de fracasar, en caso de ser necesarios. (AU)

Vinegar production via spontaneous fermentation of different prickly pear fruit matrices: changes in chemical composition and biological activities.

BACKGROUND: This study focused on the valorization of prickly pear (PP) fruit (Opuntia ficus-indica) into vinegar by spontaneous surface fermentation on different starting matrices (with/without the addition of sucrose and with/without PP peel in the raw material). Different parameters were monitored during the fermentation process in terms of their physicochemical and biological properties. RESULTS: Physicochemical and phytochemical analysis revealed significant differences depending on the starting matrix. An increase in total phenolic content (TPC) was observed for the majority of samples when transformed from PP juice into PP vinegar revealing the role of fermentation in enhancing the bioactive compounds content. Better antioxidant and antibacterial activity were detected for vinegar samples compared with the initial starting matrix. Using whole PP fruit resulted in better TPC and antioxidant activity; in contrast, sugar addition had no significant effect on any studied data. Analysis of variance, taking into account the four factors that were studied (matrix, variety, with/without peel, and with/without sugar), demonstrated that only the factor 'presence or absence of the peel' had a significant influence on the TPC values. CONCLUSION: This study demonstrated that both whole PP fruit and PP juice could be used as new raw materials for vinegar production. © 2023 Society of Chemical Industry.

Antibiotic Resistances of Enterobacteriaceae with Chromosomal Ampc in Urine Cultures: Review and Experience of a Spanish Hospital.

The Enterobacteriaceae Citrobacter freundii, Enterobacter cloacae, Klebsiella aerogenes, Morganella morganii, Providencia stuartii, and Serratia marcescens (CESPM group) produce numerous urinary tract infections (UTIs) which are difficult to treat due to their high multiresistance rate. The objectives of this study were to carry out a systematic review of antibiotic resistances by UTIs and to determine changes over time in urine cultures from a reference hospital in southern Spain. The literature was searched for European data on the resistance rates of each microorganism, and a retrospective cross-sectional descriptive study was performed in samples with suspicion of UTI from patients in Virgen de las Nieves University Hospital (Granada, Spain) between 2016 and the first half of 2021. Among 21,838 positive urine cultures, 1.85% were caused by E. cloacae, 0.77% by M. Morganii, 0.65% by K. aerogenes, 0.46% by C. freundii, 0.29% by P stuartii, and 0.25% by S. marcescens. The lowest resistance rates by microorganism were: E. cloacae to amikacin (3.47%) and imipenem (5.28%); M. morganii to piperacillin-tazobactam (1.79%), cefepime (4.76%), and tobramycin (7.74%); K. aerogenes to tobramycin (3.55%), gentamicin (4.25%), trimethoprim-sulfamethoxazole (4.96%), imipenem (5.75%), and cefepime (6.43%); C. freundii to imipenem (no resistance), nitrofurantoin (1.96%), fosfomycin (2.80%), and ertapenem (6.12%); P. stuartii to cefepime (3.28%) and ceftazidime (3.28%); and S. marcescens to gentamicin (1.8%), ciprofloxacin (3.64%), cefepime (3.70%), piperacillin-tazobactam (3.70%), and trimethoprim-sulfamethoxazole (5.45%). In our setting, CESMP Enterobacteriaceae showed the lowest resistance to piperacillin-tazobactam, cefepime, imipenem, gentamicin, and colistin, which can therefore be recommended for the empirical treatment of UTIs. The COVID-19 pandemic may have had a clinical impact in relation to the increased resistance of E. cloacae and M. morgani to some antibiotics.

Corrección del prolapso de cúpula vaginal mediante colpopexia vía abdominal

Introducción: Las disfunciones del suelo pélvico se consideran un problema de salud en el mundo y constituyen una de las indicaciones de operaciones ginecológicas más comunes. Entre sus variantes está el prolapso de la cúpula vaginal. Objetivos: Evaluar los resultados de la corrección del prolapso de cúpula vaginal por la técnica de colpopexia, mediante fijación con tiras aponeuróticas a la pared abdominal anterior. Métodos: Se realizó un estudio observacional, descriptivo. Las variables utilizadas fueron la edad, presencia de comorbilidades, el número de cirugías previas y el grado de satisfacción subjetivo de las pacientes, luego del procedimiento. Resultados: Hubo predominio de edades avanzadas en la muestra estudiada con 89,5 % de pacientes mayores de 55 años. En la mayoría de las pacientes se encontró una o más comorbilidades que favorecieron la presencia de esta afección. Un total de 8 pacientes habían sido sometidas a una cirugía correctora previa para el prolapso (30,7 %). Al mes de la cirugía el 80,7 % tenía una puntuación de 1-3 de la escala de evaluación PGI-I, valor que fue en ascenso y alcanzó el 96,1 % a los 3 meses, el 100 % a los 6 meses y al año. Conclusiones: La corrección del prolapso de la cúpula vaginal, mediante colpopexia por vía abdominal es una alternativa de tratamiento para las pacientes, fundamentalmente jóvenes o que quieren conservar la funcionalidad vaginal y la vida sexual activa.

Introduction: Pelvic floor dysfunctions are considered a health problem in the world, and constitute one of the most common indications for gynecological surgery. Among its variants is the prolapse of the vaginal vault. Objectives: To evaluate the results of the correction of the vaginal vault prolapse by the colpopexy technique by means of fixation with aponeurotic strips to the anterior abdominal wall. Methods: An observational, descriptive, retrospective study was carried out. The variables used were age, presence of comorbidities, the number of previous surgeries and the degree of subjective satisfaction of the patients after the procedure. Results: There was a predominance of advanced ages in the sample studied with 89.5% of patients older than 55 years. In most of the patients, one or more comorbidities were found that favored the presence of this condition. A total of 8 patients had undergone previous corrective surgery for the prolapse (30.7%). One month after surgery, 80.7% had a score of 1-3 on the evaluation, a value that increased and reached 96.1% at 3 months, and 100% at 6 months, and one year. Conclusions: Vaginal vault prolapse correction by mean of abdominal way colpopexy is therapeutic alternative, mainly young, and those who want to preserve vaginal functionality, and active sexual life.

Determination of Volatile Metabolites in Vinegar by Stir Bar Sorptive Extraction-Gas Chromatography-Mass Spectrometry (SBSE-GC-MS).

Stir bar sorptive extraction (SBSE) is a rapid, sensitive, precise, and environmentally friendly extraction technique that, coupled to gas chromatography-mass spectrometry detection (GC-MS), enables the simple determination of volatile organic compounds in liquid samples. The present protocol describes the procedure for the determination of volatile compounds in vinegar by means of SBSE-GC-MS.

Determination of Volatile Metabolites in Vinegar by Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry (SPME-GC-MS).

Solid-phase microextraction (SPME) is an easy, sensitive, and environmentally friendly technique that has been employed, coupled to gas chromatography or liquid chromatography, to determine a huge amount of analytes with different volatilities. The present work describes the procedure to follow in order to determine volatile compounds in vinegar by SPME-GC-MS.

Effect of the type of acetic fermentation process on the chemical composition of prickly pear vinegar (Opuntia ficus-indica).

BACKGROUND: In several countries, the cactus plant (Opuntia ficus-indica (L). Mill.) has received renewed attention because of its ecological, socio-economic and environmental role. In this study, prickly pear vinegar was produced employing two types of acetification processes: surface and submerged culture. Both acetification processes were performed at different temperatures (30, 37, 40 °C) by using two different species of thermotolerant acetic acid bacteria (Acetobacter malorum and Gluconobacter oxydans). Polyphenols and volatile compounds analyzed by ultra-performance liquid chromatography with diode array detection and stir bar sorptive extraction-gas chromatography-mass spectrometry, respectively, were considered as the main variables to determine the effect of the acetification process on the quality of the vinegar. RESULTS: As a result, 15 polyphenols and 70 volatile compounds were identified and quantified in the vinegar samples produced by both acetification processes. The results showed that the surface acetification method led to an increase in the concentration of phenolic components, which was higher than that in the submerged process. However, a significant increase in volatile compounds predominated by esters and acids was observed when submerged culture acetification was employed, whereas alcohols were predominant in surface culture vinegars. Moreover, multivariate statistical analysis showed that the components that mostly contributed to the differentiation between all vinegar samples were the volatile compounds. CONCLUSION: It has been proved that prickly pear vinegar could be successfully produced at higher temperatures than usual, by employing thermotolerant bacteria, and that the type of acetification method significantly affects the final quality of the vinegar produced. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A Study on the Influence of the Use of Sulphur Dioxide, the Distillation System and the Aging Conditions on the Final Sensory Characteristics of Brandy.

Brandy is a unique alcoholic beverage obtained from wine distillates. Numerous studies have been published on its physicochemical traits and the effect of certain elaboration variables on them, but not many studies have been carried out from a sensory point of view or that have followed standardized methods applicable to this discipline. This study intends to determine the effect that certain production variables have on the sensory characteristics of brandy. These variables are the following: The use of sulphur dioxide during the fermentation of the base wine, the subsequent distillation system, the alcohol content during aging, the botanical origin of the aging casks, and their toasting degree. For this purpose, the guidelines provided by the ISO standards for sensory analysis have been followed, and chromatic parameters have also been determined. Heavy extractions from Quercus petraea casks resulted in brandies with widely varying colors, although these were hard to distinguish using the olfactory and gustatory properties associated with the factors under study. Conversely, those brandies aged in Quercus alba casks presented very consistent greenish shades that are not traditionally associated with aged brandy. This lower extraction could explain why the aromatic traits that are found in the fresh spirit are better preserved when this type of oak is used. The spirit obtained through the distillation of SO2-free wines aged in Quercus robur presented average sensory characteristics: Good color, smooth in the mouth, and medium-intensity oak notes. The distillates that were aged at 55% ABV were later perceived as more aromatically intense with a greater oak note on the palate. On the other hand, the brandies obtained from wines without SO2 added were perceived as less alcoholic, sweeter, and more balanced, with a softer oak note.