Hazelnut (Corylus avellana L.) shells as a potential source of dietary fibre: impact of hydrothermal treatment temperature on fibre structure and degradation compounds.

BACKGROUND: Hemicellulose extraction from lignocellulosic biomasses has gained interest over the years, and hydrothermal treatment is one of the most common methods employed for this purpose. This work aimed to deeply study hazelnut (Corylus avellana L.) shells as a new source of dietary fibre, evaluating the effect of hydrothermal treatment temperatures on the type and structure of fibre extracted, but also on the formation of side-products derived from lignocellulose degradation. RESULTS: Different process temperatures led to diverse polysaccharides in the hydrothermal extract. Pectin was identified for the first time in hazelnut shells when experimenting with extraction at 125 °C, whereas at 150 °C a heterogeneous mixture of pectin, xylan, and xylo-oligosaccharides was present. The highest yield in terms of total fibre was gained at 150 and 175 °C, and then decreased again at 200 °C. Finally, more than 500 compounds from different chemical classes were putatively identified and they appeared to be present in the extracted fibre with a different distribution and relative amount, depending on the heat treatment severity. A generally high content of phenols, phenyls, oligosaccharides, dehydro-sugars, and furans was observed. CONCLUSIONS: Modulation of the hydrothermal treatment temperature allows fibre extracts with very different compositions, and therefore different potential end uses, to be obtained from hazelnut shells. A sequential temperature-based fractionation approach, as a function of the severity of the extraction parameters, can also be considered. Nevertheless, the study of the side-compounds formed from lignocellulosic matrix degradation, as a function of the applied temperature, needs to be fully addressed for a safe introduction of the fibre extract within the food chain. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A multiplatform metabolomics/reactomics approach as a powerful strategy to identify reaction compounds generated during hemicellulose hydrothermal extraction from agro-food biomasses.

Hydrothermal treatment is commonly used for hemicelluloses extraction from lignocellulosic materials. In this study, we thoroughly investigated with a novel approach the metabolomics of degradation compounds formed when hazelnut shells are subjected to this type of treatment. Three different complementary techniques were combined, namely GC-MS, 1H NMR, and UHPLC-IM-Q-TOF-MS. Organic acids, modified sugars and aromatic compounds, likely to be the most abundant chemical classes, were detected and quantified by NMR, whereas GC- and LC-MS-based techniques allowed to detect many molecules with low and higher Mw, respectively. Furans, polyols, N-heterocyclic compounds, aldehydes, ketones, and esters appeared, among others. Ion mobility-based LC-MS method was innovatively used for this purpose and could allow soon to create potentially useful datasets for building specific databases relating to the formation of these compounds in different process conditions and employing different matrices. This could be a very intelligent approach especially in a risk assessment perspective.

Production of xylo-oligosaccharides (XOS) of tailored degree of polymerization from acetylated xylans through modelling of enzymatic hydrolysis.

Xylo-oligosaccharides (XOS) are emerging prebiotics that have recently been gained a great interest in the market of functional foods. Since their beneficial activity strictly depends on their chemical structure and on their degree of polymerization (DP), in this work an enzymatic method was developed to produce XOS with variable and modellable DPs, involving a combination of a commercial endo-ß-1,4-xylanase M3 from Trichoderma longibrachiatum and a deacetylase, using a commercial acetylated standard xylan as substrate. A Design of Experiment (DoE) was developed and through the variation of some hydrolysis conditions, some experiments allowed to obtain significant amounts of XOS with DP 7-10, up to 11%, despite XOS with DP 2-4 were always the most abundant (60-96% of total XOS). The most impacting parameter on the XOS distribution was the order of addition of the xylanase and deacetylating enzyme, while pH showed to have a great influence on the total yield. The method was also tested on an acetylated xylan extracted from grape stalks, structurally similar to the commercial standard xylan. The model was found to work in a very similar way also on the non-purified xylan sample, allowing the manipulation of enzymatic hydrolysis on a low-cost by-product, with the potential to obtain on a large scale XOS with high added value and with a specific DP, depending on the final application.

Potential Valorization of Hazelnut Shells through Extraction, Purification and Structural Characterization of Prebiotic Compounds: A Critical Review.

Hazelnuts are one of the most widely consumed nuts, but their production creates large quantities of by-products, especially shells, that could be upcycled into much more valuable products. Recent studies have shown that hazelnut shell hemicellulose is particularly rich in compounds that are potential precursors of xylooligosaccharides and arabino-xylooligosaccharides ((A)XOS), previously defined as emerging prebiotics very beneficial for human health. The production of these compounds on an industrial scale-up could have big consequences on the functional foods market. However, to produce (A)XOS from a lignocellulosic biomass, such as hazelnut shell, is not easy. Many methods for the extraction and the purification of these prebiotics have been developed, but they all have different efficiencies and consequences, including on the chemical structure of the obtained (A)XOS. The latter, in turn, is strongly correlated to the nutritional effects they have on health, which is why the optimization of the structural characterization process is also necessary. Therefore, this review aims to summarize the progress made by research in this field, so as to contribute to the exploitation of hazelnut waste streams through a circular economy approach, increasing the value of this biomass through the production of new functional ingredients.

Antifungal activity of yeasts and lactic acid bacteria isolated from cocoa bean fermentations.

The aim of this study was to select yeast and LAB strains to be used as a mean of biological control against fungal growth during cocoa fermentation process. Their antifungal activity was assessed against six spoilage fungi isolated from both fermented and dried cocoa beans and belonging to Aspergillus and Penicillium genera. An initial screening was carried out by using the overlay method where the plates were examined for fungi inhibition zone around LAB and yeast streaks. Then, the most active strains were studied in inhibition test in 96-well microplates where mould growth was measured by microplate reader at 490 nm. The nature of their antifungal strenght (organic acid and/or proteins) was also evaluated. The most promising candidates as biological agents belonged to the species Lactobacillus fermentum, Lactobacillus plantarum, Saccharomyces cerevisiae and Candida ethanolica and their antifungal strength was attributed mainly to organic acid production (for LAB) and proteinaceous compounds (for yeasts) or to their synergic effect.

Molecular and taxonomic characterisation of introduced specimens of Poecilia reticulata in the lower Paraguay River basin (Cyprinodontiformes: Poeciliidae)

Poeciliids comprise around 300 species inhabiting the fresh and brackish waters of the Americas and Africa. Poecilia reticulata is native to Northeastern South America and Trinidad and Tobago. In this paper, introduced specimens of P. reticulata collected in the lower Paraguay River in Argentina, were characterized by means of molecular and taxonomic approaches. We further explore, by means of DNA Barcoding, the singularity of the genetic identity of these specimens. Ocurrence of P. reticulata in the lower Paraguay River represents the first record of this species in Argentina. Thirteen individuals of P. reticulata were collected. DNA barcoding showed that all five specimens sampled belong to a single mitochondrial lineage, which was also present in 11 countries from five continents. The distance-based tree clearly grouped separetely four different clusters of P. reticulata when including public data. Genetic distance between the most divergent P. reticulata almost paralleled distance between this species and Poecilia mexicana and P. vivipara. Established populations from Paraguay could be one of the plausible sources for the introduced populations recorded in the lower Paraguay River. The presence of P. reticulata in an open waterway with known drainage to a natural stream is of major concern.(AU)

Poecilídeos compreendem cerca de 300 espécies que habitam águas doces e salobras das Américas e África. Poecilia reticulata é nativa do nordeste da América do Sul e Trinidad e Tobago. Neste trabalho, espécimes introduzidos de P. reticulata coletados no baixo rio Paraguai na Argentina, foram caracterizados por meio de abordagens moleculares e taxonômicas. Exploramos ainda, por meio de DNA Barcoding, a singularidade da identidade genética destes espécimes. A ocorrência de P. reticulata no baixo rio Paraguai representa o primeiro registro dessa especie na Argentina. Treze indivíduos de P. reticulata foram coletados. O Barcoding mostrou que todos os espécimes pertencem a uma única linhagem mitocondrial, a qual está presente em 11 países dos cinco continentes. A árvore de distâncias agrupou separadamente quatro clusters diferentes de P. reticulata quando incluindo dados públicos. A distância genética entre os agrupamentos mais divergentes de P. reticulata quase igualou a distância entre esta espécie e Poecilia mexicana e P. vivipara. As populações estabelecidas no Paraguai poderiam ser uma das fontes plausíveis para as populações introduzidas registradas no baixo rio Paraguai. A presença de P. reticulata em um canal aberto com drenagem conhecida para um córrego natural é de grande preocupação.(AU)

Genital diseases awareness in young male students: Is information necessary to protect them?

INTRODUCTION: Few studies on the prevalence of male sexual diseases are currently available due to difficult application of observational studies or andrological disease prevention campaigns on large series of apparently healthy subjects. The medical check-up linked to compulsory military service represented in Italy a valid tool for epidemiological and observational study for 18 year old boys from 1861 to 2004. The stopping of compulsory military service and its related medical check-up could have determined an important social impact in terms of a lower level of attention and care on male genital/sexual diseases. The aim of the present observational study was to check the prevalence of genital/sexual diseases among young male high-school students and promote an alternative campaign of information among young students. METHODS: A prospective observational analytical study on young male students was conducted by 6 urological centres. Genital and sexually transmitted diseases were presented with slides to students in a general assembly. Some students were then counselled and filled out a short questionnaire on their lifestyle. RESULTS: 12,535 students (10,432 males-83.6%) followed the presentation. and 4,897 males (46.7%) decided to be checked-up by the urologist and out of them 1554 (31.7%) presented relevant andrological diseases. Five-hundred students completed the questionnaire concerning their lifestyle. Many of them had not yet experienced condom use during sexual intercourse (27.8%). Drug abuse was reported by 39.6% of subjects and alcohol consumption in 80.8% of them. CONCLUSIONS: These data suggest the need for a national information campaign on male sexual disorders to promote sexual health.

Utilización del Score de Alvarado en el diagnóstico de apendicitis aguda / Use of Alvarado's socre for the early diagnosis of acute appendicitis

La apendicitis aguda no sospechada y diagnosticada puede evolucionar hacia la perforación, o por el contrario conduce a la remoción de un apéndice normal. Objetivo del trabajo: la utilización de un sistema de Score, desde un punto de vista clínico, para el diagnóstico de esta patología y lograr disminuir las apendicectomías negativas

Utilización del Score de Alvarado en el diagnóstico de apendicitis aguda / Use of Alvarados socre for the early diagnosis of acute appendicitis

La apendicitis aguda no sospechada y diagnosticada puede evolucionar hacia la perforación, o por el contrario conduce a la remoción de un apéndice normal. Objetivo del trabajo: la utilización de un sistema de Score, desde un punto de vista clínico, para el diagnóstico de esta patología y lograr disminuir las apendicectomías negativas

Quantitative evaluation of bacteria adherent to polyelectrolyte HEMA-based hydrogels.

The use of adhesive poly(HEMA)-based hydrogels is standard practice in dental restorative procedures. Microorganisms, which potentially can cause oral pathologies, may colonize these polymers. In the present work, bacterial adhesion to polymers prepared with 2-hydroxyethyl methacrylate (HEMA) and to different molar ratios of 2-acrylamido-2-methylpropane-sulfonic acid (AMPS) and/or to 2-methacryloyloxyethyl-tri-methyl-ammonium chloride (METAC) co-monomers were tested. A colorimetric assay system that utilizes the Microbo revelation medium (Microbo srl, Rome, Italy) for microbial counts is shown to be capable of counting the number of adherent bacterial cells without removing them from polymer surfaces. In conditions that mimic those present in the oral cavity, similar bacterial adhesion percentages on the same polymer were observed with the different bacteria belonging to both gram-positive and gram-negative genera, such as Streptococcus sobrinus and Streptococcus oralis (resident microorganisms in the oral cavity) and Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa (transient microorganisms in the oral cavity). It is determined that the physico-chemical characteristics of poly(HEMA)-based hydrogels are the major factors promoting bacterial adhesion, which increased with increasing water content in the swollen polymers, reaching maximal values on the cationic polymers.