Biogenic amines (BAs) generally result from the decarboxylation reaction of free amino acids as a result of the activity of different microorganisms. A build-up of these compounds can result in food being spoilt. Therefore, the rapid and precise detection of BAs like histamine is an important task for food safety. This research aimed to explore the potential of Fourier-Transform Mid-Infrared (FT-MIR) spectroscopy combined with chemometric methods to assess histamine in fresh tuna quantitatively. Based on the FT-MIR data, partial least squares regression models for the prediction of histamine were successfully constructed with R2 > 0.90. Machine learning algorithms (partial least squares-discrimination analysis, k-nearest neighbors, and support vector machine) were applied, and excellent discrimination results were achieved based on the limits specified in two different legislations (EU and FDA). The results support the use of a rapid, economic and reliable approach for the discrimination of samples that could pose a health risk to consumers.

Abstract The ready availability of abundant food sources can be a key factor in the success of biological invasions. This study provides information about feeding habits, dietary niche, and seasonal and ontogenetic diet changes of the American invasive weakfish Cynoscion regalis in the Gulf of Cádiz, where its population is increasing exponentially since 2011 when its presence was reported in the area. By content analysis of 340 stomachs, we assessed the diet composition, prey diversity and abundance of juveniles and adults present in the Guadalquivir River Estuary. Fish and crustaceans accounted for more than 90% of their diet. Mysids are the main food intake for juveniles and piscivory becomes more important as C. regalis grows in size. Stomachs were significantly fuller during the summer and autumn months, coinciding with the higher abundance of small pelagic fish during that time in the estuary, especially the anchovy Engraulis encrasicolus, the main prey consumed through all months of the year, that showed a consumption peak in September and October. Adults also show significant monthly variations in the diet composition (P < 0.01) respect to Total Length. Juveniles show a specialist behaviour feeding almost exclusively on Mesopodopsis slabberi, while adults show a mixed feeding strategy. This research constitutes a comprehensive study of weakfish diet along the year in the non-native area, including for the first time, juvenile’s stages.

Botryosphaeria dieback is a canker disease caused by fungal species of the Botryosphaeriaceae family that threatens almond productivity. The most common control measure to prevent canker development is the application of fungicides which are being phased out by European Union regulations. In the present study, two sets of bacterial strains were evaluated for their antifungal activity against pathogenic Botryosphaeriaceae species through in vitro and in vivo antagonism assays. The rhizospheric bacteria Pseudomonas aeruginosa AC17 and Bacillus velezensis ACH16, as well as the endophytic bacteria Bacillus mobilis Sol 1-2, respectively inhibited 87, 95, and 63% of the mycelial growth of Neofusicoccum parvum, Botryosphaeria dothidea, Diplodia seriata, and Macrophomina phaseolina. Additionally, they significantly reduced the length of lesions caused by N. parvum and B. dothidea in artificially inoculated detached almond twigs. All these bacterial strains produce hydrolytic enzymes that are able to degrade the fungal cell wall. P. aeruginosa AC17 also produces toxic volatile compounds, such as hydrogen cyanide. This strain was the most effective in controlling Botryosphaeria dieback in planta under controlled conditions at a level similar to the biocontrol agent Trichoderma atroviride and standard chemical fungicide treatments. Pseudomonas aeruginosa AC17 is the best candidate to be considered as a potential biocontrol agent against Botryosphaeriaceae fungi affecting almond. © 2023 Society of Chemical Industry.

The endophallus of Timarcha kiesenwetteri ssp. sagrensis is herein described for the first time. Its morphology is simple. It has a long basal lobe and a large medial lobe which narrows progressively to a small apical diverticulum. Timarcha kiesenwetteri is an extremely rare species from Southern Spain. It is so rare it has been found very infrequently in the last century.

Durum wheat cultivation in Mediterranean regions is threatened by abiotic factors, mainly related to the effects of climate change, and biotic factors such as the leaf rust disease. This situation requires an in-depth knowledge of how predicted elevated temperatures and [CO2] will affect durum wheat-leaf rust interactions. Therefore, we have characterised the response of one susceptible and two resistant durum wheat accessions against leaf rust under different environments in greenhouse assays, simulating the predicted conditions of elevated temperature and [CO2] in the far future period of 2070–2099 for the wheat growing region of Cordoba, Spain. Interestingly, high temperature alone or in combination with high [CO2] did not alter the external appearance of the rust lesions. However, through macro and microscopic evaluation, we found some host physiological and molecular responses to infection that would quantitatively reduce not only pustule formation and subsequent infection cycles of this pathogen, but also the host photosynthetic area under these predicted weather conditions, mainly expressed in the susceptible accession. Moreover, our results suggest that durum wheat responses to infection are mainly driven by temperature, being considered the most hampering abiotic stress. In contrast, leaf rust infection was greatly reduced when these weather conditions were also conducted during the inoculation process, resembling the effects of possible heat waves not only in disease development, but also in fungal germination and penetration success. Considering this lack of knowledge in plant-pathogen interactions combined with abiotic stresses, the present study is, to the best of our knowledge, the first to include the effects of the expected diurnal variation of maximum temperature and continuous elevated [CO2] in the durum wheat-leaf rust pathosystem.

AbstractThe flowering time, which determines when the fruits or seeds can be harvested, is known to be sensitive to plasticity, i.e. the ability of a genotype to display different phenotypes in response to environmental variations. In the context of climate change, strawberry breeding can take advantage of phenotypic plasticity to create high-performing varieties adapted either to local conditions or to a wide range of climates. To decipher how the environment affects the genetic architecture of flowering time in cultivated strawberry (Fragaria ×ananassa) and modify its QTL effects, we used a bi-parental segregating population grown for two years at widely divergent latitudes (5 European countries) and combined climatic variables with genomic data (Affymetrix® SNP array). We detected 10 unique flowering time QTL and demonstrated that temperature modulates the effect of plasticity-related QTL. We propose candidate genes for the three main plasticity QTL, includingFaTFL1which is the most relevant candidate in the interval of the major temperature-sensitive QTL (6D_M). We further designed and validated a genetic marker for the 6D_M QTL which offers great potential for breeding programs, for example for selecting of early-flowering strawberry varieties well adapted to different environmental conditions.HighlightsA GXE study of a segregating strawberry population in Europe showed that temperature is the main driver of flowering time plasticity. A genetic marker was designed for the main QTL.

Orange peel is an interesting by-product because of its composition, particularly its dietary fibre and flavanones. The aim of this work was to extract different fibre fractions from orange peel to obtain potential added-value ingredients and evaluate how the presence of fibre may interfere with (poly)phenol metabolism. Using an aqueous extraction, as a green extraction method, an insoluble fibre fraction (IFF) and a water-soluble extract (WSE) were obtained. Those fractions were analysed to determine the proximate and dietary fibre composition, hydration properties, (poly)phenol composition and antioxidant capacity, comparing the results with the orange peel (OP). The IFF presented the highest content of insoluble dietary fibre and the WSE showed the highest content of (poly)phenols, these being mainly flavanones. An in vitro faecal fermentation was carried out to evaluate the production of short-chain fatty acids (SCFAs) and lactate as prebiotic indicators; the IFF gave the highest production, derived from the greater presence of dietary fibre. Moreover, catabolites from (poly)phenol metabolism were also analysed, phenylpropanoic acids being the major ones, followed by phenylacetic acids and benzoic acids. These catabolites were found in higher quantities in WSE, because of the greater presence of (poly)phenols in its composition. IFF also showed a significant production of these catabolites, which was delayed by the greater presence of fibre. These results reveal that the new ingredients, obtained by an environmentally friendly water extraction procedure, could be used for the development of new foods with enhanced nutritional and healthy properties.

Amino acids have proved to play a key role in the development of volatile compounds present in wine with determining repercussions on the final wine bouquets. Biogenic amines originate from the chemical transformations of amino acids found in various foods, a phenomenon that has given rise to several health-related concerns among consumers. In the present research, the evaluation of two of the most influential factors: variety (genetic) and year (climatic conditions) on these compounds in grapes has been performed. Eight Vitis vinifera varieties have been collected during three years and the content of nineteen amino acids, two biogenic amines, and the ammonium ion has been quantified using the HPLC-PDA technique. The genetic factor has proved to be an influential variable (p-value < 0.05) with mean values of amino acids ranging from 896.89 to 1713.79 mg/L and of biogenic amines ranging from 10.61 to 22.28 mg/L. The climatic conditions have shown to be an influential factor as well (p-value < 0.05), being the low temperatures and rainfall and the high solar radiation favour the development of the amino acid and avoid biogenic amines accumulation in grapes.

Crop modelling is a critical tool for assessing the impact of climate change and for evaluating adaptation strategies to ensure the sustainability of agricultural systems. In addition to increased temperature and reduced precipitation, studying the effects of increased atmospheric CO2 concentration ([CO2]) and water stress on water efficiency of crops is highly relevant for identifying and evaluating impacts and new adaptation measures. We carried out 12 experiments with 4 faba bean cultivars under controlled conditions of [CO2], temperature and water supply. An increase of [CO2] from 430 to 650 ppm caused a 20% reduction in stomatal conductance under optimal irrigation supply but had almost zero effect under water stress conditions. Our study shows that the beneficial effect of a higher atmospheric [CO2] on faba bean growth is counteracted by water stress, with the beneficial effect only detected when proper water management is applied. Thus, stomatal conductance appeared to be more sensitive to water stress than to elevated [CO2], indicating that the beneficial effects of elevated [CO2] on faba bean are largely dependent on the plant water status. This is particularly relevant in Mediterranean agricultural systems, where water shortage associated with droughts will become more frequent, even in areas of irrigation. Although differences in the response between cultivars were observed in our study when the water status was intermediate between optimal and severe drought, no single genotype among those studied will be sufficient to improve or fully guarantee yield under conditions of increasing [CO2] and water shortage. Therefore, the introduction of irrigation and/or sowing date strategies currently represent the only adaptation measures. The gaps in knowledge of the response of faba bean to climate change, and the limited number of adaptation measures available highlight the need for continued research, with breeding of drought-tolerant and high-yielding faba bean genotypes as one of the most promising alternatives.

The present work was conducted to evaluate the volatile profile of Ecuadorian Forastero, CCN-51, ETT103 and LR14 cocoa beans during traditional fermentation in laurel wood boxes followed by a sun-drying process. Fifty-six volatiles were identified with HS-SPME-GC-MS. Aldehydes, alcohols and ketones were the compounds that mainly characterized the fresh cocoa. The main compounds formed during the anaerobic fermentation step were esters and acids, while in the aerobic fermentation step, an increase in ester-, aldehyde- and acid-type compounds was observed. Finally, after the drying step, a notable increase in the acid (i.e., acetic acid) content was the predominant trend. According to the genotypes, ETT103 presented high contents of terpenes, alcohols, aldehydes and ketones and low contents of unfavorable acid compounds. The CCN-51 and LR14 (Trinitarian) varieties stood out for their highest amounts in acids (i.e., acetic acid) at the end of primary processing. Finally, the Forastero cocoa beans were highlighted for their low acid and high trimethylpyrazine contents. According to the chemometric and Venn diagram analyses, ETT-103 was an interestingly high-aromatic-quality variety for cocoa gourmet preparations. The results also showed the need for good control of the processing steps (using prefermentative treatments, starter cultures, etc.) on Ecuadorian genotypes of Trinitarian origin.