Thermal and Non-Thermal Physical Methods for Improving Polyphenol Extraction in Red Winemaking

Maceration-fermentation is a critical stage in the elaboration of high-quality red wine. During this stage, the solid parts of the grape berries remain in contact with the fermenting must in order to extract polyphenols mainly located in the grape skin cells. Extracted polyphenols have a considerable impact on sensory properties (color, flavor, astringency, and bitterness) and on the aging behavior of red wine. In order to obtain wines with a sufficient proportion of those compounds, long maceration times are required. The presence of the solid parts of the grapes during red wine fermentation involves several problems for the wineries such as production capacity reduction, higher energy consumption for controlling the fermentation temperature and labor and energy consumption for periodically pump the grape must over the skin mass. Physical techniques based on heating such as thermovinification and flash expansion are currently being applied in wineries to improve the extraction of polyphenols and to reduce maceration time. However, these techniques present a series of problems derived from the heating of the grapes that affect wine quality. A series of recent studies have demonstrated that non-thermal innovative technologies such as pulsed electric fields (PEF) and ultrasound may represent effective alternatives to heating for assisting polyphenol extraction. In terms of general product quality and energetic requirements, this review compares these thermal and non-thermal physical technologies that aim to reduce maceration time

Two-step PEF processing for enhancing the polyphenol concentration and decontaminating a red grape juice

This study’s aim is to evaluate Pulsed Electric Fields (PEF) technology as an alternative method for the processing of red grape juice. For this purpose, two PEF treatments were applied: first to grapes for polyphenol enrichment of the juice, and subsequently for microbial decontamination of the obtained juice. Juice obtained from PEF-treated grapes (5 kV/cm, 63.4 kJ/kg) had the polyphenol content 1.5-fold higher and colour intensity two times higher of control juices by spectrophotometric measurement (p = 0.05). A subsequent decontamination treatment by PEF (17.5 kV/cm and 173.6 kJ/kg) achieved inactivation of the present microbiota (yeasts, moulds, and vegetative mesophilic bacteria) below detection level (<30 CFU/mL). Furthermore, PEF-treated juices were microbiologically stable up to 45 days, even at abusive refrigeration storage temperatures (10 °C). PEF juice quality and sensory characteristics were similar to a fresh juice; they were neither affected by the PEF decontamination treatment, nor by storage time and temperature. Results obtained in this study demonstrate the considerable potential of PEF for the production of a polyphenol-enriched and microbially stabilized red grape juice as a unique and sustainable alternative for the juice industry, while avoiding enzymatic and heat treatments

Nuevas citas de Parasquilla ferussaci (Roux, 1830) (Crustacea, Stomatopoda) en el Atlántico oriental y Mediterráneo occidental

En esta nota se informa sobre la presencia del estoma­tópodo Parasquilla ferussaci en las costas de la península ibérica. La documentación está basada en tres especímenes capturados, respectivamente, en Isla Cristina (Huelva) en el Golfo de Cádiz, Fuengirola (Málaga) en el Mar de Alborán y en Gavà (Barcelona) en el Me­diterráneo noroccidental. Se amplia la distribución conocida de la especie completando así el vacío existente hasta el momento entre las citas atlánticas y las del Mediterráneo central. Palabras clave: Parasquilla ferussaci, Estomatópodo, Mediterráneo occidental, Golfo de Cádiz.We report the occurrence of the little known stomatopod Parasquilla ferussaci on the Atlantic and Mediterranean coasts of the Iberian peninsula. Documentation is based on three specimens captured off Isla Cristina (Huelva) in the Gulf of Cadiz, off Fuengirola (Málaga) in the Alboran Sea and off Gavà (Barcelona) in the North-Western Mediterranean. These reports fill the distribution gap between Eastern Central Atlantic reports and previous Mediterranean reports east of the Balearic Islands. Key words: Parasquilla ferussaci, Stomatopoda, Western Mediterranean, Gulf of Cadiz.En esta nota se informa sobre la presencia del estoma­tópodo Parasquilla ferussaci en las costas de la península ibérica. La documentación está basada en tres especímenes capturados, respectivamente, en Isla Cristina (Huelva) en el Golfo de Cádiz, Fuengirola (Málaga) en el Mar de Alborán y en Gavà (Barcelona) en el Me­diterráneo noroccidental. Se amplia la distribución conocida de la especie completando así el vacío existente hasta el momento entre las citas atlánticas y las del Mediterráneo central. Palabras clave: Parasquilla ferussaci, Estomatópodo, Mediterráneo occidental, Golfo de Cádiz

Taxonomic study of the Pagurus forbesii "complex" (Crustacea: Decapoda: Paguridae). Description of pagurus pseudosculptimanus sp. nov. from alborán sea (Southern Spain, Western Mediterranean Sea)

Study of hermit crabs from Alboran Sea has allowed recognition of two different morphological forms under what had been understood as Pagurus forbesii. Based on morphological observations with various species of Pagurus, and molecular studies, a new species is described as P. pseudosculptimanus. An overview of species of Pagurus from the eastern Atlantic and Mediterranean Sea is provided. © Copyright 2014 Magnolia Press.This work was supported by the Junta de Andalucía RNM-0141 Research Group.Peer Reviewe

Study of ni/al-fe catalyst stability in the aqueous phase hydrogenolysis of glycerol

The present work studied the stability and reusability of Ni/Al-Fe catalyst in the aqueous phase hydrogenolysis of glycerol without external hydrogen addition. The catalyst based on 28 molar % of Ni with 3/1 molar ratio of Al/Fe was prepared through co-precipitation. This catalyst presented the best performance in our last study which compares several Ni/Al-Fe catalysts with different molar ratios of Al/Fe. To see the influence of the pressurized water on the physicochemical characteristics of Ni/Al-Fe catalyst, a test of up to 9 h has been carried out. Fresh and used catalysts were characterized by various techniques: X-ray Diffraction (XRD), N2-physisorption, field emission scanning electron microscopy (FESEM) and STEM. Glycerol conversion and carbon yield to gases and liquids did not vary significantly when compared at 3 h and 9 h. Furthermore, the morphology of the catalyst remains stable after continuous recycling under severe hydrothermal conditions. The nickel rich phase of the catalyst, which was determined by XRD and scanning transmission electron microscopy (STEM) techniques, showed a stable size after 9 h under reaction

Quality-Based Thermokinetic Optimization of Ready-to-Eat Whole Edible Crab (Cancer pagurus) Pasteurisation Treatments

Traditional processing practices used in the manufacture of ready-to-eat edible crab products include a double-heat treatment involving an initial cooking step followed by washing and packaging and finally, a second heat pasteurisation. The latter, pasteurisation step, results in the most severe impact on product quality. The main objective of this research was to optimise this pasteurisation step using quality index degradation kinetic approach. Preliminary work involved the characterisation of temperature rise in the crab cold-spot during pasteurisation. Equivalent treatments (F90°C 10°C = 10 min) were defined in order to assess the impact of pasteurisation temperature on different crab quality indexes in both crab meat types, white and brown. Colour degradation of crab white meat was defined as the critical quality parameter to be monitored during thermal pasteurisation. The effect of time and temperature on the kinetics of white meat colour change (¿E*) were characterised and fitted to an exponential equation. Following this, an industry focus group was used to define white meat colour change vs product quality and defined ‘good’ (¿E* = 7), ‘acceptable’ (7 &lt; ¿E* &lt; 9) and ‘unacceptable’ (¿E* = 9) quality. Finally, using the developed equations, optimal pasteurisation conditions were defined and validated. To produce ‘good’ quality crab, optimal temperatures ranged between 96 and 100 °C while temperatures between 104 and 108 °C produced ‘acceptable’ quality in crabs of 400 and 800 g, respectively. Overall, the results show that the equations obtained could be used in a decision support system (DSS) to define heat pasteurisation conditions to optimise the quality of ready-to-eat edible crab

Pulsed electric fields as a green technology for the extraction of bioactive compounds from thinned peach by-products

Thinned fruits are agricultural by-products which nowadays have few economic or environmental benefits. However, previous studies have revealed that these immature fruits have a large amount of antioxidant compounds. The aim of this study was to evaluate whether pulsed electric fields (PEF) might be a suitable green technology for enhancing the extraction of phenols, flavonoids and antioxidant compounds from fresh thinned peaches, thus reducing the use of methanol. Moreover, response surface methodology has been used to determine the optimal PEF treatment conditions, observing that the solvent is the main factor. The highest amounts of bioactive compounds were extracted using 80% methanol and no PEF. Methanol combined with PEF produced a negative effect on the extraction yield. However, the use of water as a solvent increased the amount of total bioactive compounds and individual phenols (chlorogenic acid, coumaric acid and neochlorogenic acid). Thus, PEF-assisted extraction of bioactive compounds from thinned peach fruits using water as a solvent is an alternative to conventional extraction methods which require dried products, large amounts of organic solvents and long extraction times

Bythocaris cosmetops (Decapoda: Caridea: Hippolytidae) in the western Mediterranean Sea

The capture of the species Bythocaris cosmetops in the Alboran Sea (southern Spain, western Mediterranean Sea), previously known from only two specimens from the Atlantic, Sierra Leone (south-west Africa) and the northern Bay of Biscay (north-west Europe), represents the first record of the genus and species in the Mediterranean Sea and Iberian Peninsula (south-west Europe). New data on morphology, biology and habitat are provided and discussed.Postprint0,000