A life in the surf zone: Age and feeding habits of the pompano (Trachinotus ovatus, Linnaeus, 1758) on the beaches of the Gulf of Cádiz (south-west Iberian Peninsula).

Surf zones are crucial habitats for many fish species, where they spend the initial stages of their lives, finding food and shelter. One such species is the pompano (Trachinotus ovatus). The aim of this study was to examine the age and diet of the pompano within the surf zone, along with any potential variations in the environment. The average size of the specimens was 10.61 ± 4.91 cm. The length-weight relationship was total weight (TW) = 0.0136*total length (TL)2.8512 (parameter a: 95% C.I.: 0.0130-0.0142 and parameter b: 95% C.I.: 2.8318-2.8705). The most abundant age classes were 0+ and 1+, making up 97% of the captured specimens, with significant differences in the abundance of age classes depending on the time of the day and season. The pompano primarily fed on clupeiforms, copepods, and mysids, with significant variations in diet based on the time of the day, season, and size of the specimens. This study contributes new information about the use of the surf zone by T. ovatus in its early years of life, underscoring the importance of these areas and their role as an additional ecosystem service.

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.

Exploring morphometric frontiers: A comprehensive study of otolith growth patterns in brown comber Serranus hepatus (Linnaeus, 1758).

Otoliths are widely employed in marine sciences to gain insights into fish growth, age, migrations, and population structure. This study investigates the relationships between morphometric measurements, otolith characteristics, and length size patterns in the brown comber (Serranus hepatus) from the Gulf of Cádiz, a species discarded in artisanal trawl fisheries. Our findings reveal significant changes in otolith shape indices as fish grow, with symmetry observed between left and right otolith measurements. Otolith size is found to be related to fish size, supporting its use in estimating body length at different life stages. Otolith shape analysis has potential applications in stock identification, detecting catch misreporting, and studying marine predator diets. Combining otolith shape analysis with other data types can clarify relationships among taxa and inform spatial management strategies, contributing to the long-term sustainability of fish populations and the assessment of the impact of management strategies on fish size and growth. This study enhances our understanding of the broader implications of morphometric and otolith analyses in fisheries research and supports the development of more sustainable fisheries management practices.

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.

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.

Effect of climatic oscillations on small pelagic fisheries and its economic profit in the Gulf of Cadiz.

Several studies have shown the effect of climatic oscillations on fisheries. Small pelagic fish are of special global economic importance and very sensitive to fluctuations in the physical environment in which they live. The main goal of this study was to explore the relationship between the North Atlantic Oscillation (NAO), the East Atlantic pattern (EA), and the Arctic Oscillation (AO) on the landings and first sale prices of the most representative small pelagic commercial species of the purse-seine fisheries in the Gulf of Cadiz (North East Atlantic), the European anchovy Engraulis encrasicolus and the European sardine Sardine pilchardus. Generalised linear models (GLMs) with different data transformations and distribution errors were generated to analyse these relationships. The best results of the models were obtained by applying a moving average of order 3 to the dataset with a double weighted median. Our results demonstrate relationships between NAO, AO, and EA and European anchovy and sardine landings. These cause an indirect effect on the first sale price in markets through catch variations, which affect the price according to the law of supply and demand. The limitations of this study and management implications are discussed.

Influence of fermentation temperature and yeast type on the chemical and sensory profile of handcrafted beers.

BACKGROUND: Various physicochemical parameters, the polyphenolic content, the volatile fraction as well as the sensory profile of beers were studied using five different yeast strains (three top-fermentation and two bottom-fermentation) and two different fermentation temperatures (12 and 18 °C) for each of them. RESULTS: The results indicated that at lower fermentation temperatures, the yeast strain factor was less significant for the various physicochemical parameters considered. The polyphenolic content increased as the fermentation temperature decreased, and significantly higher amounts of tyrosol were found in the samples fermented at 12 °C. However, the volatile content increased for beers fermented at 18 °C, these beers being better evaluated from the sensory point of view. CONCLUSIONS: No clear relationship was observed between the temperature used and the type of yeast, with more complex aroma and sensory profiles being found in beers fermented at higher temperatures, using yeasts that are supposedly suitable for use at lower temperatures. © 2020 Society of Chemical Industry.

Application of accelerating energies to the maceration of sherry vinegar with citrus fruits.

BACKGROUND: In the present work we propose the use of accelerating energies (microwaves and ultrasounds) to the maceration process of sherry vinegar with citrus fruit peels (orange and lemon). For the application of microwaves, an experimental design has been developed in order to optimize the maceration conditions. To evaluate the effect of these energies on the maceration, the volatile and polyphenolic content of the samples has been analyzed, as well as their sensory characteristics. RESULTS: Orange peel provided a higher number of volatile and polyphenolic compounds to the vinegar, while lemon's yielded a greater amount of some of them. The multivariate analysis showed that the samples macerated using microwaves were the most similar to the samples macerated in the traditional way. This aspect was corroborated by the sensory analysis, which was more noticeable when orange peel was used in the macerations. CONCLUSION: Therefore, it seems that the use of microwaves to accelerate maceration is a good alternative to the traditional method of making sherry vinegars macerated with citrus peel, since it cuts down the maceration time from 3 days to just a few minutes. © 2020 Society of Chemical Industry.

Effect of different cooking methods on sea lettuce (Ulva rigida) volatile compounds and sensory properties.

BACKGROUND: The effect of different cooking methods (boiling, vacuum and steamed cooking) on the volatile compound content and sensory properties of sea lettuce (Ulva rigida) seaweed was assessed. Sea lettuce was cooked at three different temperatures (50, 70 and 100 °C) for three different lengths of time (5, 10 and 15 min). Various statistical techniques were employed in order to establish any possible changes. RESULTS: The different cooking methods modified significantly both the volatile compound content and the sensory properties of sea lettuce seaweed. In general, the cooked samples had lower concentrations of several volatile compounds than the control sample, mainly aldehydes. Regarding sensory analysis, the cooked samples exhibited lower values for various aroma descriptors such as seaside and seaweed, whereas descriptor scores such as cooked fish, salty dry fish and crustacean increased. No clear statistical differences were found between different cooking lengths of time and temperature levels with regard to both volatile compounds and sensory properties. CONCLUSIONS: In the cooking of sea lettuce seaweeds, the main sensory changes and modifications in their volatile content took place during the first minutes of cooking and at medium cooking temperatures. © 2020 Society of Chemical Industry.

Effect of the type of wood used for ageing on the volatile composition of Pedro Ximénez sweet wine.

BACKGROUND: The present study investigated the volatile composition of a Pedro Ximénez sweet wine that had been aged in barrels made of different types of wood (Spanish oak, French oak, American oak and chestnut) and subjected to different degrees of toasting (medium toasting and intense toasting). The analyses were carried out using stir bar sorptive extraction gas chromatography-mass spectrometry after validation of the matrix in this case. RESULTS: Good values of linearity, precision, limits of detection and limits of quantification were obtained for the 36 compounds studied, six of which were identified for the first time in Pedro Ximénez (propyl acetate, cis-3-hexenyl acetate, benzyl acetate, guaiacol, trans-whiskeylactone and 4-ethylguaiacol). The volatile composition of the samples varied as the ageing process progressed, and higher volatile concentrations were obtained in samples aged in barrels that had been intensely toasted compared to in those with medium toasting. A multivariate statistical study allowed the samples to be correctly classified according to ageing time, wood toasting and the type of wood used for ageing. CONCLUSION: The organoleptic analysis performed on the Pedro Ximénez sweet wine samples resulted in differences between the wines aged in the different types of wood during the early weeks of ageing, and scarce differences towards the end of the study period. At the end of the process, all of the wines were better valued and wines aged in medium toasted barrels were the best rated by the panel of judges for all four woods under investigation. This fact could indicate the suitability of alternative woods for the ageing of Pedro Ximénez sweet wines. © 2020 Society of Chemical Industry.

Evolution of volatile compounds and sensory characteristics of edible green seaweed (Ulva rigida) during storage at different temperatures.

BACKGROUND: Edible seaweeds are one of the most important resources that currently exist for their multiple uses and applications. Like other food types, during their storage there are significant changes in sensory characteristics associated with loss of freshness and with production and/or degradation of their volatile compounds. In this study, multiple headspace sorptive extraction (MHSSE) coupled with gas chromatography/mass spectrometry (GC/MS) detection has been applied to an edible green seaweed (Ulva rigida) in order to determine the evolution of volatile compounds during storage for 12 days at 4 or 16 °C. RESULTS: The existing analytical methodology has been updated and validated for 18 additional compounds. At the end, 41 volatile compounds from different chemical families were quantified. Aldehydes, carboxylic acids and esters were the main classes found in U. rigida. Analytical and sensory data were submitted for statistical analysis. During storage, most volatile compounds were only affected by the number of storage days (P < 0.05), with significant decreases as storage time increased. Sensory analysis revealed significant changes in the samples stored for longer times (8, 10 and 12 days), with a clear influence of the boiled vegetable descriptor. CONCLUSION: In order to get a successful preservation of seaweeds and to maintain their marine character during storage, both temperature and time should be carefully controlled. © 2019 Society of Chemical Industry.

Benchmarking laboratory-scale pomegranate vinegar against commercial wine vinegars: antioxidant activity and chemical composition.

BACKGROUND: There is growing interest in the beneficial health effects of certain fruits, such as pomegranate, and their by-products, like vinegar. Vinegars contain antioxidant compounds such as polyphenols, which can scavenge free radicals in the body. In this study, the antioxidant properties (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid and 2,2-diphenyl-1-picrylhydrazyl scavenging capacities) and global polyphenolic composition of a new functional product, namely a pomegranate vinegar produced in the laboratory from the Gabsi variety, were evaluated and compared with those of commercial wine vinegars (Sherry and Rioja red wine Spanish vinegars). The evolution of the polyphenolic and volatile compositions during production of the pomegranate vinegar was also studied. RESULTS: The results indicate that pomegranate contained a relatively stable total phenolic content that is suitable for the elaboration of vinegar and that this product had an antioxidant capacity comparable to, or even better than, that observed for aged wine vinegars. Regarding the volatiles profile, a high proportion of esters (close to 50%), in relation to alcohols and fatty acids, was observed for pomegranate vinegar, and this is consistent with the high red fruits character identified by sensory analysis. CONCLUSION: Pomegranate vinegar produced in the laboratory has an antioxidant activity and a global phenolic content similar to those of red wine vinegars and higher than most of the white wine vinegars studied. The pomegranate vinegar retained the red fruit sensory character of pomegranate fruit. © 2018 Society of Chemical Industry.

Application of a stir bar sorptive extraction method for the determination of volatile compounds in different grape varieties.

BACKGROUND: Stir bar sorptive extraction (SBSE) has been employed for the analysis of aroma compounds directly from Spanish and Italian grape extracts. The extraction conditions have been optimized using a statistical approach, obtaining results that improve the current state of the art. RESULTS: The proposed analytical conditions were: sample volume 40 mL, extraction time 80 min, 25% (w/v) NaCl and stirring speed 750 rpm using 20 mm × 0.5 mm stir bars. Performance characteristics of the SBSE procedure were further studied and showed correlation coefficients, detection and quantification limits, linear ranges, recoveries and precision values adequate for analysing these compounds in grapes. Twenty-four grape varieties (aromatic and non-aromatic) were analysed. Statistically significant differences (P < 0.05) according to geographical origin were found, being derived mainly from the terpenoid content. By principal component analysis it was possible to note that the terpenoids were more effective in the separation of the non-aromatic samples, showing negative and positive scores for Italian and Spanish grapes, respectively. CONCLUSION: For non-aromatic grape varieties, the factor 'geographic location' was the most significant, thus corroborating the high influence of this parameter on the volatile composition of grapes and therefore on the genuineness of wines. © 2016 Society of Chemical Industry.

Development of a stir bar sorptive extraction method for the determination of volatile compounds in orange juices.

A stir bar sorptive extraction method for the determination of volatile compounds in orange juices was developed. The extraction variables were optimized using a reduced two-level factorial screening design (2(5-1) ), and the most suitable analytical conditions for the extraction of the studied compounds were: sample volume 10 mL, extraction time 60 min, stirring speed 1800 rpm, NaCl amount 30% (weight/volume), and twister length 10 mm. The optimized method was further validated, obtaining good linearity and detection and quantification limits low enough to correctly determine the studied compounds. As well, for most of the studied compounds precision and recovery values were good. Several orange juice samples (squeezed and commercial) were extracted following the optimized extraction method and analyzed by gas chromatography coupled to mass spectrometry detection. The method has proven to be suitable for the determination of the aroma of orange juice, of which limonene was the major volatile compound in all the studied samples.

Development of a new stir bar sorptive extraction method for the determination of medium-level volatile thiols in wine.

A fast, simple, and reliable analytical method for the determination of medium-level volatile thiols in wines is presented. Stir bar sorptive extraction using ethylene glycol-silicone coated stir bars has been used in combination with thermal desorption gas chromatography with mass spectrometry for the analysis of 4-mercapto-4-methylpentan-2-one, 2-furanmethanethiol, 3-mercaptohexyl acetate, and 3-mercaptohexanol in wine. Optimization of the extraction technique was performed using a two-level fractional factorial design. For the extraction step, the optimum conditions were: Ethylene glycol and silicone coated stir bars, pH at 3.5, sample volume of 25 mL, extraction time of 90 min, NaCl content 4.0 g, and stirring speed at 500 rpm. The optimized method achieved good linearity for all studied compounds (r(2) > 0.995) and it provided detection limits of 21.52, 0.36, 0.73, and 2.55 µg/L for 4-mercapto-4-methylpentan-2-one, 2-furanmethanethiol, 3-mercaptohexyl acetate, and 3-mercaptohexanol, respectively. It was repeatable, with precisions lower than 18% relative standard deviation for both intraday and interday repeatability. The developed procedure is suitable for the determination of these kinds of compounds when they are present at medium concentration levels. It was finally applied to real wine samples with negative aroma derived from the high concentration levels of these compounds.

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.

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.

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.

Artisanal trawl fisheries as a sentinel of marine litter pollution.

Systematic seafloor surveys are a highly desirable method of marine litter monitoring, but the high costs involved in seafloor sampling are not a trivial handicap. In the present work, we explore the opportunity provided by the artisanal trawling fisheries to obtain systematic data on marine litter in the Gulf of Cadiz between 2019 and 2021. We find that plastic was the most frequent material, with a prevalence of single-use and fishing-related items. Litter densities decreased with increasing distance to shore with a seasonal migration of the main litter hotspots. During pre-lockdown and post-lockdown stages derived from COVID-19, marine litter density decreased by 65 %, likely related to the decline in tourism and outdoor recreational activities. A continuous collaboration of 33 % of the local fleet would imply a removal of hundreds of thousands of items each year. The artisanal trawl fishing sector can play a unique role of monitoring marine litter on the seabed.