http://hdl.handle.net/10498/6782 2026-11-05T19:02:43Z 2026-11-05T19:02:43Z Rendón, A.B Malfeito-Ferreira, M. Lasanta Melero, Cristina Morata, A. http://hdl.handle.net/10498/40482 2026-10-30T05:00:44Z 2026-01-01T00:00:00Z

Analytical and sensory characterisation of Palo Cortado in comparison with Amontillado and Oloroso Sherry wines Rendón, A.B; Malfeito-Ferreira, M.; Lasanta Melero, Cristina; Morata, A. This research focuses on the analytical and sensory characterisation of Palo Cortado Sherry wines, using Amontillado and Oloroso as reference styles across the spectrum of biological to oxidative ageing in the Jerez region. Sensory evaluation and physicochemical analyses were carried out on samples from six wineries, including GC-FID, FTIR, and colour measurements (absorbances and CIELAB). Results revealed both common patterns among wines within styles and distinguishing factors among them. Significant differences were mainly observed in sensory attributes, colour parameters, and specific volatile compounds. Despite intra-style variability, certain grouping patterns emerged, allowing partial differentiation of the styles and revealing greater proximity between Palo Cortado and Oloroso. Acetaldehyde concentrations were 50 % higher in Amontillado than in Oloroso, and 37 % higher than in Palo Cortado. In contrast, ethyl acetate concentrations were approximately 30 % higher in Oloroso and Palo Cortado than in Amontillado, with similar values between the former two. These results emphasise the influence of the ageing processes on the concentration of these characteristic volatile compounds.

2026-01-01T00:00:00Z Pérez González, Juan Manuel Sancho Galán, Pau Amores Arrocha, Antonio Jiménez Cantizano, Ana Concepción http://hdl.handle.net/10498/40461 2026-10-27T05:08:49Z 2026-05-07T00:00:00Z

Suitability of Spanish Local White Grape Cultivars for Warm Climates Pérez González, Juan Manuel; Sancho Galán, Pau; Amores Arrocha, Antonio; Jiménez Cantizano, Ana Concepción Plant genetic resources are increasingly viewed as a key tool to address the multiple challenges faced by modern viticulture. In this context, local grape cultivars are proposed as a strategy to enhance resilience to climate change and to diversify wine styles. However, while genetic identification has been widely reported, field-based phenotyping information for local cultivars under current climate conditions remains limited. In this context, phenotyping results are presented for six local Andalusian cultivars (Castellano, Beba, Cañocazo, Mantúo de Pilas, Perruno and Vigiriega). All cultivars were grown in a vineyard plot in the Marco de Jerez and evaluated over three consecutive seasons (2023–2025). Morphology was assessed using 46 descriptors, allowing cultivars to be grouped into two main clusters. Phenological monitoring showed a measurable year effect while preserving a consistent relative ranking among cultivars, most clearly during veraison and ripening, with Castellano reaching these stages earlier and Mantúo de Pilas later. Grape must composition highlighted contrasting ripening dynamics, with Palomino Fino and Castellano generally reaching higher sugar levels, whereas Vigiriega and Mantúo de Pilas showed the most acidic profiles. These results provide growers with performance-based comparative information to support cultivar selection for new plantings and to explore the potential of local cultivars for developing new wine styles under warm climate conditions.

2026-05-07T00:00:00Z Caro Pina, Ildefonso Romero Vargas, Agustín Díaz Villanueva, Manuel Jesús Huertas, Julia http://hdl.handle.net/10498/40311 2026-10-03T04:01:57Z 2026-01-01T00:00:00Z

A kinetic model for polyhydroxyalkanoates production by Cupriavidus necator using dark fermentation effluents Caro Pina, Ildefonso; Romero Vargas, Agustín; Díaz Villanueva, Manuel Jesús; Huertas, Julia Polyhydroxyalkanoates (PHAs) represent a family of biodegradable polymers that are precursors of bioplastics, offering a sustainable alternative to plastics derived from fossil fuels, within a circular economy framework. This study investigates the production of PHAs by the Cupriavidus necator bacterium, using as carbon sources synthetic media with volatile fatty acids (VFAs) and real effluents from dark fermentation (DFE) of seaweed wastes, which contain this type of acids. Experimental results indicate that, when acids are fermented singly, propionic acid yields a lower polymer quantity than acetic or butyric acids. However, when VFAs are supplied in mixtures, synergistic effects are observed. The kinetic models actually published fail to account for the increasing alkalinity of the medium during the VFA consumption, which frequently leads to biomass growth inhibition, and do not incorporate pH-dependent growth equations or consider the deleterious impact of alkaline conditions on the polymer stability. Thus, a novel kinetic model is proposed, based on the Monod equation, but integrating the inhibitory effects of pH in the biomass growth and the alkaline polymer degradation, with only nine fitting parameters. The new model allow for the robust prediction of the PHA production, the substrate consumption and the biomass growth, in the experimental conditions applied, which are typical of the PHA fermentations of DFE. The overall regression coefficient of theoretical curves (R2) is over 0.92, thus facilitating the designing and optimization of the industrial-scale processes.

2026-01-01T00:00:00Z Erdocia, Xabier Ruiz, Encarnacion Romero, Inmaculada Díaz Villanueva, Manuel Jesús Castro, Eulogio Labidi, Jalel http://hdl.handle.net/10498/40129 2026-07-30T04:10:21Z 2017-01-01T00:00:00Z

Lignin characterization from two different pretreatments in bioethanol production processes from olive tree pruning Erdocia, Xabier; Ruiz, Encarnacion; Romero, Inmaculada; Díaz Villanueva, Manuel Jesús; Castro, Eulogio; Labidi, Jalel Biomass generated from pruning of olive trees is an abundant lignocellulosic residue that has been proposed for bioethanol production by means of a process including pretreatment, enzymatic hydrolysis, and fermentation. The pretreatment is critical step in the process, which allows the fractionation of the biomass. Lignin is the main byproduct of the process, and then its valorization is a key factor for the economical viability of the bioethanol production from olive tree pruning. In this work, two types of pretreatments have been compared steam explosion and organosolv in terms of the produced lignin suitability for further applications in the so-called new biorefinery concept. Starting from this fact, special emphasis was given to determine the physico-chemical properties of lignins produced by the two processes in order to determine their suitability for the development of added value products (e.g. materials, building blocks, additives). Overall, the lignin obtained from organosolv pretreatment had better properties for its further valorization as it presents more suitable qualities for higher-added value applications like fine phenolic chemicals production.

2017-01-01T00:00:00Z