https://hdl.handle.net/10259/5827 2026-04-19T07:50:41Z 2026-04-19T07:50:41Z Ortega Sanz, Irene Rovira Carballido, Jordi Megías, Gregoria Rivero Pérez, Maria Dolores Melero Gil, Beatriz https://hdl.handle.net/10259/11287 2026-01-27T01:05:58Z 2025-08-01T00:00:00Z

Genome-Wide association study to identify genetic markers associated with Campylobacter jejuni motility Ortega Sanz, Irene; Rovira Carballido, Jordi; Megías, Gregoria; Rivero Pérez, Maria Dolores; Melero Gil, Beatriz The ability of Campylobacter jejuni to survive and persist under harsh conditions is linked to the presence of flagella. This structure promotes the motility of the bacteria towards their optimum environment. The aim of this study was to examine the genetic basis for motility within 136 C. jejuni isolates through two different Genome-Wide Association Studies, gene presence/absence and Single Nucleotide Polymorphisms (SNPs). The motility phenotype was widely distributed across the phylogeny with large intra-lineage swarming performance variabilities. Accessory genes significantly associated with motility were found in four key genomic regions. One of these regions affected the Cj0727-Cj0733 operon, that encodes a putative ABC transporter system for phosphate uptake, while other influenced the capsule biosynthesis locus. Multiple SNPs mostly linked to increased motility were also discovered in clusters of genes, with special relevance to transport and membrane proteins. Therefore, the capsule and membrane composition might influence nutrient transfer, further impacting the protonmotive force that drives flagellar motor rotation in C. jejuni. The study provides novel genetic markers with a potential role in the motility phenotype of the pathogen.

2025-08-01T00:00:00Z Polanco-Estibález, Berta García-Santa-Cruz, Rodrigo Queirós, Rui P. Serment-Moreno, Vinicio González Angulo, Mario Tonello Samson, Carole Rivero Pérez, Maria Dolores https://hdl.handle.net/10259/11286 2026-01-27T01:05:56Z 2023-12-01T00:00:00Z

High-Pressure Processing for Cold Brew Coffee: Safety and Quality Assessment under Refrigerated and Ambient Storage Polanco-Estibález, Berta; García-Santa-Cruz, Rodrigo; Queirós, Rui P.; Serment-Moreno, Vinicio; González Angulo, Mario; Tonello Samson, Carole; Rivero Pérez, Maria Dolores Cold brew coffee (CBC) has gained in popularity due to its distinct sensory experience. However, CBC can pose a risk for bacterial pathogens if not stored properly. High-Pressure Processing (HPP) is a nonthermal technology that can improve the safety of CBC while maintaining its quality. In this study, CBC made from ground roasted coffee grains was processed at 600 MPa for 3 min and stored at 4 or 23 °C for 90 days. The microbiological quality indicators remained stable throughout the study period. Physicochemical and quality parameters, such as pH, total dissolved solids, titratable acidity, color, total phenolic compounds and antioxidant activity, were not significantly affected by HPP. Both unprocessed and HPP CBC samples showed changes in pH, titratable acidity and color stability after 60 days at 23 °C. Unprocessed CBC samples spiked with Escherichia coli O157:H7, Listeria monocytogenes and Salmonella enterica showed decreased counts, but the pathogens were still detectable after 60 days at 4 °C and after 90 days at 23 °C. HPP achieved a >6-log10 reduction in the species tested, with non-detectable levels for at least 90 days at both storage temperatures. These findings suggest that HPP can effectively control vegetative pathogens and spoilage microorganisms in CBC while preserving its quality attributes.

2023-12-01T00:00:00Z Correia, Ana C. González San José, Mª Luisa Ortega Heras, Miriam Jordão, António M. https://hdl.handle.net/10259/11219 2026-01-16T01:05:56Z 2023-09-01T00:00:00Z

Preliminary Study of the Effect of Short Maceration with Cherry and Oak Wood Chips on the Volatile Composition of Different Craft Beers Correia, Ana C.; González San José, Mª Luisa; Ortega Heras, Miriam; Jordão, António M. In the last few years, the production and consumption of craft beers has increased notably. However, there is restricted knowledge about the potential impact of chips from different wood species on beer quality. Thus, this work aimed to evaluate the effect of the addition of wood chips from cherry and oak species—after the fermentation was completed and during a brief maceration time—on the volatile composition of three different beer groups (Ale, Lager, and Porter) through a headspace solid-phase dynamic extraction (HS-SPDE) and GC-MS analysis. Fifty-six volatile compounds from different chemical families (esters, alcohols, terpenes, acids, aldehydes, ketones, and pyrazines) were detected, identified, and considered in this study. In general, the volatile composition of the beers macerated with wood chips was very similar to that of the control beers. However, the control beers showed higher volatile compound levels. The results suggest potential interactions between beer volatile compounds and the wood chips during maceration. The outcomes of this research could be of practical interest to brewers since they could improve the knowledge of the impact of short-time contact and low wood chip concentration on the volatile composition of different craft beers.

2023-09-01T00:00:00Z Jordão, António M. Correia, Ana Cristina Botelho, Renato Vasconcelos Ortega Heras, Miriam González San José, Mª Luisa https://hdl.handle.net/10259/11218 2026-01-16T01:05:30Z 2024-10-01T00:00:00Z

Phenolic content, volatile composition and sensory profile of red wines macerated with toasted woods from different South American botanical species Jordão, António M.; Correia, Ana Cristina; Botelho, Renato Vasconcelos; Ortega Heras, Miriam; González San José, Mª Luisa The use of wood species from South American origin was not previously considered for wine aging. Thus, this work focuses on the comparative analysis of phenolic content, volatile composition and sensory characteristics of a red wine macerated with woods, in form of toasted cubes, from jequitibá, jaqueira, ipê, amburana and lenga species. All wines macerated with these woods showed a tendency for an increase of the phenolic parameters evaluated. This tendency was more evident in wine chromatic characteristics, especially for the wine macerated with jequitibá wood, where significantly higher color intensity and total color difference values was detected. For volatile composition, the different wood species induced significant changes on wine volatile profile. Thus, 3-hydroxy-4-phenyl-2-butanone was only detected in wine macerated with jaqueira wood, while benzophenone, ethyl pentadecanoate, D-citronellol, linalool, geranic acid and isovainillic acid were only detected in wine macerated with amburana wood. For sensory profile, wine macerated with amburana wood showed significantly higher scores for “coconut”, “toasted” and “floral” aroma descriptors, while for taste and overall appreciation this wine also showed a tendency for a slightly higher score. The outcomes of this research improved the knowledge of the use of several South American wood species on red wine characteristics.

2024-10-01T00:00:00Z