Impact of salt reduction on biogenic amines, fatty acids, microbiota, texture and sensory profile in traditional blood dry-cured sausages

Meat industry needs to reduce salt in their products due to health issues. The present study evaluated the effect of salt reduction from 6% to 3% in two Portuguese traditional blood dry-cured sausages. Physicochemical and microbiological parameters, biogenic amines, fatty acids and texture profiles and sensory panel evaluations were considered. Differences due to salt reduction were perceptible in a faint decline of water activity, which slightly favoured microbial growth. Total biogenic amines content ranged from 88.86 to 796.68 mg kg 1 fresh matter, with higher amounts, particularly of cadaverine, histamine and tyramine, in low-salt products. Still, histamine and other vasoactive amines remained at low levels, thus not affecting consumers’ health. Regarding fatty acids, no significant differences were observed due to salt. However, texture profile analysis revealed lower resilience and cohesiveness in low-salt products, although no textural changes were observed by the sensory panel. Nevertheless, low-salt sausages were clearly preferred by panellists.

Preparação, caracterização e modificação de adsorventes para remoção de pesticidas de águas

O objectivo principal deste trabalho de mestrado consistiu em avaliar a potencial utilização de materiais adsorventes, nomeadamente, de carvões activados (AC) preparados por activação química com KOH, a partir de PET reciclado, e de materiais com estrutura mesoporosa ordenada, do tipo MCM-41 e SBA-15, na remoção de ácido 4 - cloro - 2 - metilfenoxiacético (MCPA) e de azul de metileno (MB), presentes nas águas. Nesta tese apresentam-se estudos de preparação e caracterização de materiais micro e mesoporosos e também estudos de avaliação da capacidade adsortiva em fase líquida. Prepararam-se três materiais microporosos, nomeadamente, PET-2-700, PET-2-700ox (AC oxidado) e PET-2-700red (AC reduzido), dois materiais constituídos exclusivamente por mesoporos, Si-MCM-41 e Ti-MCM-41-50 e dois materiais contendo maioritariamente mesoporos, mas que também possuem alguma microporosidade, tais corno, Si-SBA-15 e Ti-SBA-15-50. A caracterização textural dos adsorventes foi inferida por adsorção de azoto a 77K e por de difracção de raios X. Recorreu-se a três métodos de análise das isotérmicas, nomeadamente, Dubinin-Radushkevich, Brunauer-Ernrnett-Teller e alfa-s (as). A caracterização química dos AC foi realizada recorrendo-se a técnicas de análise elementar (AE) e espectroscopia de infravermelho com transformadas de Fourier (FTIR) e à determinação do ponto de carga zero. Os três carvões activados possuem valores de área superficial externa idênticos, o PET-2-700 possui o maior volume microporoso e o PET-2-700ox exibe o maior diâmetro de poros. Por outro lado, o PET-2-700ox possui um carácter fortemente ácido, o PET-2-700 exibe carácter ligeiramente ácido e o PET-2-700red apresenta propriedades ligeiramente alcalinas. Com base na AE, todas as amostras possuem percentagens de carbono elevadas, sendo que o PET-2-700red apresenta o valor mais elevado. Os resultados obtidos para a caracterização estrutural dos revelaram a obtenção de materiais mesoporosos de alta qualidade, definida pela elevada regularidade e uniformidade da estrutura porosa. A análise dos parâmetros de caracterização textura! permitiu inferir que os quatro materiais mesoporosos possuem valores de área superficial elevados, e que os materiais SBA-15 apresentam valores de volume poroso total e de tamanho de poros superiores aos manifestados pelos MCM-41. A incorporação de titânio não conduziu a uma perda significativa de qualidade dos materiais substituídos em relação às correspondentes amostras de sílica. Efectuaram-se estudos de adsorção em fase líquida de forma a avaliar a possível aplicação dos vários adsorventes na remoção de MCPA e de MB de efluentes líquidos. concluiu-se que o tempo de equilíbrio de 72 horas seria adequado e que a capacidade de adsorção dos vários AC era superior em meio ácido. Com base nas isotérmicas de adsorção do MCPA e do MB e na aplicação da representação de Langmuir e de Freundlich, foi possível concluir que o PET-2-700 possui a maior capacidade de adsorção do MCPA, 1.42 mmol/g, enquanto que o PET-2-700ox revelou a maior capacidade de adsorção do MB, 1.43 mmol/g. Na realidade, os materiais microporosos estudados apresentaram percentagens de remoção elevadas, tanto do MCPA como do MB. Relativamente aos materiais mesoporosos ordenados preparados neste trabalho, a percentagem de remoção de para os poluentes em estudo foi relativamente baixa, constatando-se que nesta fase dos estudos não constituem uma alternativa viável à utilização dos AC. No entanto, uma funcionalização criteriosa dos mesmos pode eventualmente proporcionar um aumento da capacidade adsortiva. ABSTRACT: The work presented in this master thesis, consisted of evaluating the potential use of different adsorbents materials, like activated carbon (AC) prepared by chemical activation with KOH, from recycled poly (ethylene terephthalate) (PET) and materials with ordered mesoporous structure such as MCM-41 and SBA-15, for removing acid 4-chlorine-2-metilfenoxiacétic and methylene blue from aqueous phase. We had prepared three microporous materials, PET-200-700, PET-2-700ox (AC oxidized) and PET-2-700red (reduced AC), two materials consisting exclusively of mesopores, Si-MCM-41 and Ti-MCM-41-50 and two materials containing mainly mesopores, but also having some microporosity, such as Si-SBA-15 and Ti-SBA-15-50. The textural characterization of the adsorbents was inferred by nitrogen adsorption at 77K and X-ray diffraction. Three methods were used to analyse the isotherms, namely, Dubinin-Radushkevich, Brunauer-Emmett-Teller and alpha-s (as). The chemical characterization of AC was performed using the elementary analysis, Fourier transform infrared spectroscopy (FTIR) and determination of the point of zero charge. Concerning the AC, the three present almost the same externa! surface area, PET-2-700 has a high micropore volume and PET-2-700ox shows the largest pore size diameter. On the other hand, PET-2-700ox had a strong acid character, PET-2-700 exhibits just a slightly acid character and PET-2-700red presents alkaline properties. The AE analysis allows confirming the high carbon content of theses AC, with PET-2-700red exhibiting the highest carbon proportion. The results from the structural characterization of the mesoporous materials, had disclosed the attainment of materials with high quality, defined by the raised regularity and uniformity of the porous structure. The analysis of the textural parameters allowed inferring that the four studied mesoporous materials possess high superficial area. The SBA-15 type materials present higher values of total porous volume and pores size diameter as the MCM-41. Also, the titanium incorporation did not lead to a significant loss of quality of the materials substituted in relation to the corresponding silica samples. The adsorption studies in liquid phase allow evaluating the possibility of using the different adsorbents for the MCPA and the MB removal. The kinetic studies had allowed to state the equilibrium time as 72 hours and a higher adsorption capacity was achieved in an acid medium. The influence of the pH of the medium, on the MCPA adsorption was evaluated. The MCPA and MB isotherms were analysed based on the Langmuir and Freundlich equation, the representations presented an excellent linearity, indicating the applicability of these equations to these systems. Also, it allows concluded that PET-2-700 had a higher adsorption capacity for MCPA, 1.42 mmol/g, and PET-2-700ox had a higher adsorption capacity for MB, 1.43 mmol/g. The AC used presented high removal percentages for MCPA and MB. Concerning the mesoporous materials prepared in this work, the percentage removal for the pollutants in study was relatively low, and evidencing that at the moment these mesoporous materials do not constitute a viable alternative to the AC. However, an astute funcionalisation of the same ones can, eventually provide an increase of the adsorption capacity.

Avaliação do impacto de eventos comerciais de milho Bt sobre a microbiota do solo.

2016

A MODIFICAÇÃO DA PAISAGEM DO LITORAL DO PARANÁ A PARTIR DOS PROCESSOS DE OCUPAÇÃO E URBANIZAÇÃO: PAISAGEM, CULTURA E ARTE

Este texto trata dos processos de modificação da paisagem da zona costeira paranaense, desde a ocupação deste território até a atualidade. Tem como linha de condução paralela a este processo, a produção artística paranaense tendo como referencial a representação imagética encontrada nas aquarelas, gravuras e pinturas produzidas no e sobre o litoral do Paraná, neste mesmo período de tempo. O entendimento ampliado da arte unido ao entendimento da história do litoral do Paraná, sua ocupação, as mudanças de sua paisagem a partir de sua colonização e urbanização; a maneira como são hoje utilizados estes espaços urbanos e o entendimento das dificuldades advindas da falta de um planejamento urbano no litoral paranaense possibilitam compreender cada vez mais suas especificidades, características e idiossincrasias.

Impacto do manejo agrícola sobre a microbiota do solo.

Para avaliar o efeito do manejo agrícola de solo sobre os parâmetros biológico, bioquímico e químico, três propriedades agrícolas de Suzano/SP foram selecionadas contendo os seguintes tratamentos: áreas de manejo biodinâmico com o cultivo de hortaliças, áreas de manejo convencional com o cultivo de milho, área de pastagem (8 anos) e área de mata nativa. Amostras de solo foram submetidas as analises química, bioquímica e biológica. Os resultados mostraram que alguns parâmetros biológicos (bactérias esporulantes, actinomicetos, microrganismos celulolíticos), químico (pH, CTC, MO) e bioquímico (desidrogenase, polissacarídeos) foram superiores nas áreas de manejo biodinâmico em relação ao manejo convencional.

Impacto de mudanças climáticas globais sobre a microbiota terrestre.

2008

Impacto de xenobióticos e metais pesados na microbiota do solo.

2008

Probiotics for the prevention/treatment of human diseases and ecological study of the intestinal microbiota

The interest in human intestinal microbiota has increased in the last 20 years and significant advances have been achieved with regard to its composition and functions. The gut microbiota contributes to the maintenance of the host health status and, since alterations in the gut microbiota have been involved in the pathogenesis/progression of some diseases, several studies have focused on the manipulation of its composition. Probiotics are a strategy to maintain/restore the correct balance of gut microbial population and to prevent/treat diseases. The aim of this thesis was to explore the possibility of probiotic supplementation for the prevention/treatment of human diseases and the related study of the intestinal microbial environment. After reviewing studies concerning the use of Bifidobacterium breve as probiotic in paediatric diseases, the effectiveness of a probiotic formulation consisting of two strains of B. breve was assessed in paediatric subjects for the prevention or alleviation of gastrointestinal disorders, including coeliac disease and paediatric obesity. As the emerging role of gut microbiota in neurological diseases, the intestinal microbial environment in amyotrophic lateral sclerosis patients compared to healthy controls and the effects of a probiotic administration were examined. Considering the role of viruses in shaping gut microbiota, gut bacteriophages and bacterial community of preterm infants were investigated. The results evidenced differences in gut microbial composition of healthy controls and diseased subjects in coeliac and amyotrophic lateral sclerosis patients. The probiotic approach was effective in restoring the microbial composition in the former, whereas, in the latter, the influence was focused only on some microbial groups. The probiotic intervention was effective in improving the glyco-insulinemic profile in obese children and in preventing gastrointestinal disorders in healthy newborns. The study of the bacterial and phage composition in preterm infants suggested a transkingdom interplay between bacteria and viruses with a reciprocal influence on their composition.

Ruolo del Microbiota Intestinale Nella Risposta al Trattamento con Anticorpi anti Checkpoints Immunitari in Pazienti Affetti da Linfoma

L’interazione tra il sistema immunitario dell’ospite e la cellula tumorale rappresenta uno degli elementi cardine dello sviluppo del clone neoplastico: la capacità della cellula cancerosa di evadere il controllo immunitario sfruttando meccanismi fisiologici come i checkpoint immunitari è alla base di diverse neoplasie, incluse le sindromi linfoproliferative. Lo sviluppo di anticorpi monoclonali che bloccano selettivamente l’interazione tra il recettore trans-membrana PD-1 (programmed death -1) ed i propri ligandi (PD-L1 e PD-L2), rappresenta una delle scoperte terapeutiche più promettenti in ambito onco-ematologico. Nonostante l’importante efficacia antitumorale degli anticorpi anti checkpoint immunitari dimostrata dai differenti studi clinici condotti sia in ambito oncologico che ematologico, una parte dei pazienti, a parità di patologia e di farmaco ricevuto, non risponde alla terapia o sviluppa eventi avversi immuno-relati. La comprensione della variabilità di risposta dimostrata dai pazienti con stessa patologia, sottoposti a stesso trattamento rappresenta pertanto un punto chiave allo scopo di identificare strategie che possano potenziare l’efficacia terapeutica di tali anticorpi, riducendone gli effetti collaterali. Studi recenti hanno evidenziato il ruolo del microbiota intestinale (MI) nel modellare la risposta immunitaria sistemica e, nel contesto neoplastico, nel modificare e mediare l’attivazione del sistema immunitario ad agenti chemio-immunoterapici. È noto che il MI sia un ecosistema plastico che può riorganizzare funzionalità e composizione in maniera adattativa in risposta a diversi fattori ambientali. La struttura individuale del MI e la sua dinamicità temporale possono, pertanto, influenzare l’outcome delle chemio-immunoterapie onco-ematologiche, modulandone l’efficacia e la tossicità. In questo scenario, ipotizziamo che la caratterizzazione longitudinale (pre, durante e post-terapia) del MI di pazienti affetti da linfoma trattati con anticorpi anti-checkpoint inibitori e la sua correlazione con la risposta al trattamento e con lo sviluppo di eventi avversi possa avere un ruolo nel delineare l’outcome di tali pazienti e nell’identificare nuovi criteri di stratificazione del rischio.

Can gut microbiota analysis be beneficial for ex-situ and in-situ conservation of threatened animal species?

Ex-situ conservation and the in-situ conservation of natural habitats are the tools to conserve biodiversity. Habitats and ecosystems have been becoming altered by human activities and a growing number of species requires form of management to ensure their survival. Conservation queries become more complex and urgent. Developing scientifically based and innovative approaches to ex-situ conservation is necessary. Recent studies underline importance of gut microbiome in animal health with implications for animal conservation and management. Animal and human studies have demonstrated that environmental factors can impact gut microbiome composition. Within this scenario, the present work focused on species belonging to different taxa, reptiles and mammals: Aldabrachelys gigantea, the giant tortoise of the Seychelles islands and Indri indri, the greatest leaving lemur of Madagascar. The Seychelles giant tortoise is vulnerable species with declining population, whereas the indri is a critically endangered species that could reach the extinction within 25 years. Both need research to help them to survive. Tortoises live for very long time and to observe how they can afford the environmental changes is very difficult. Indris, instead, are able to survive only in a small area of the Madagascar forest, with a very strong link between the species’ survival and the environment. The obtained results underline importance of environmental factors, both in-situ and ex-situ, for species conservation. Microbiome could help the organisms to respond on a short timescale and cope with, environmental changes. However, species with long generation time might not be able to adapt to fast changes but bacteria with a short generation time can adapt on a shorter timescale allowing the host to cope with fluctuating environment. Gut microbiome plays an important role in an animal’s health and has the potential to improve the management of individuals under human care for conservation purposes.

Effetto sul microbiota intestinale della sostituzione dei nitriti con antiossidanti naturali in salami sperimentali

Recentemente il consumo di carne ha attirato l'attenzione per motivi salutistici, ambientali ed etici; pertanto è sempre più urgente considerare formulazioni di prodotti a base di carne più salutari e sostenibili inclusi in una dieta sana e nutriente. In questa tesi sono stati valutati gli effetti in vitro sul microbiota intestinale umano di salami riformulati sostituendo i nitriti con acido ascorbico e antiossidanti vegetali. A questo scopo è stato utilizzato il modello intestinale in vitro MICODE, nella versione che include la digestione gastro-duodenale seguita dalla fermentazione colonica. Gli effetti sul microbiota intestinale sono stati valutati attraverso tecniche di analisi quantitativa Real Time qPCR in base agli shift di alcune popolazioni microbiche, sia quelle benefiche (come Lactobacillales, Bifidobacteriaceae, Clostridium gruppo IV), sia quelle opportuniste (come Enterobacteriaceae, Clostridium gruppo I) e infine il rapporto Firmicutes/Bacteroidetes (importante indice di eubiosi del microbiota intestinale dell’ospite). Inoltre, sono state analizzate, tramite SPME-GC-MS, le molecole volatili prodotte in seguito alla fermentazione colonica, sia positive, come gli SCFA, sia negative, come fenolo e cresolo. I risultati ottenuti hanno mostrato che le formulazioni innovative promuovono una generale eubiosi del microbiota intestinale e una riduzione di popolazioni microbiche negative, in confronto ai controlli. Inoltre, l’analisi del volatiloma evidenzia una maggiore produzione di molecole benefiche e una maggiore riduzione delle molecole negative per l’ospite. Sebbene le formulazioni innovative non abbiano dato benefici nettamente superiori a quelli dei controlli, i risultati ottenuti sono promettenti, in quanto gli antiossidanti utilizzati in sostituzione hanno dato risultati comparabili a quelli ottenuti con il formulato tradizionale.

Relazione tra carica virale, reazione immunitaria dell'ospite, microbiota e decorso clinico della bronchiolite acuta nei bambini con età inferiore ai 12 mesi (RMB2018)

Il principale motivo di ospedalizzazione del lattante è la bronchiolite acuta, causata in primis dal Virus Respiratorio Sinciziale (VRS). In questo ambito appaiono controversi i risultati in letteratura riguardo: carica del VRS, risposta immunitaria ed infiammatoria dell’ospite, microbiota del paziente (durante l’infezione e per successivo sviluppo di wheezing e asma). In questo studio di coorte prospettico monocentrico vengono arruolati lattanti peraltro sani ricoverati per primo episodio di bronchiolite acuta, da VRS o da altro agente, per valutare primariamente la relazione tra decorso clinico e carica del VRS, secondariamente l’associazione con specifiche composizioni e modifiche nel tempo del microbiota nasofaringeo ed intestinale durante la fase acuta e nel lungo termine in relazione a sviluppo di wheezing ricorrente. Nello studio sono stati arruolati finora 89 pazienti, di cui 68 con bronchiolite da VRS (76.4%), con analisi della carica virale su 41 lattanti (60.3%) e del microbiota su 20 (29.4%). L’analisi della carica del VRS non ha riscontrato associazione tra outcome di severità clinica quali necessità e durata di ossigenoterapia, nonché durata di ricovero. La presenza di trend di associazione tra carica virale all’ingresso e picco del VRS-RNA con necessità di ossigenoterapia ad alto flusso (HFNC) e l’associazione significativa di clearance di VRS con HFNC (p = 0.03) suggeriscono che la carica virale potrebbe influenzare la severità della bronchiolite da VRS. Le analisi del microbiota evidenziano numerosi genera mai descritti finora in letteratura a nostra conoscenza (es. Alloiococcus e Leptotrichia su aspirato, nonché tutti i dati emersi dallo studio della saliva, prima volta in letteratura) ed un generale aumento della diversity a 6 mesi dalla dimissione. Occorrerà completare l’analisi della carica del VRS con quella del sistema infiammatorio dell’ospite, nonché studiare il microbiota sui campioni del follow-up a lungo termine per la verifica di eventuali associazioni con sviluppo di wheezing e asma.

Gut microbiota perturbation induced by emerging dietary habits: an in vitro colon model to predict their effects by a microbiomic and metabolomic approach

Over the past 30 years, unhealthy diets and lifestyles have increased the incidence of noncommunicable diseases and are culprits of diffusion on world’s population of syndromes as obesity or other metabolic disorders, reaching pandemic proportions. In order to comply with such scenario, the food industry has tackled these challenges with different approaches, as the reformulation of foods, fortification of foods, substitution of ingredients and supplements with healthier ingredients, reduced animal protein, reduced fats and improved fibres applications. Although the technological quality of these emerging food products is known, the impact they have on the gut microbiota of consumers remains unclear. In the present PhD thesis, the recipient work was conducted to study different foods with the substitution of the industrial and market components to that of novel green oriented and sustainable ingredients. So far, this thesis included eight representative case studies of the most common substitutions/additions/fortifications in dairy, meat, and vegetable products. The products studied were: (i) a set of breads fortified with polyphenol-rich olive fiber, to replace synthetic antioxidant and preservatives, (ii) a set of Gluten-free breads fortified with algae powder, to fortify the protein content of standard GF products, (iii) different formulations of salami where nitrates were replaced by ascorbic acid and vegetal extract antioxidants and nitrate-reducers starter cultures, (iv) chocolate fiber plus D-Limonene food supplement, as a novel prebiotic formula, (v) hemp seed bran and its alkalase hydrolysate, to introduce as a supplement, (vi) milk with and without lactose, to evaluate the different impact on human colonic microbiota of healthy or lactose-intolerants, (vii) lactose-free whey fermented and/or with probiotics added, to be introduced as an alternative beverage, exploring its impact on human colonic microbiota from healthy or lactose-intolerants, and (viii) antibiotics, to assess whether maternal amoxicillin affects the colon microbiota of piglets.

Different dietary fibres included in the gestation and lactation diet shape sow's microbiota, modify colostrum and milk composition and affect piglet growth and health

This thesis reports three experimental studies that may contribute to understand how the sources or types of dietary fibres (DFs) included in sow diet with similar level of total DFs influence the composition of colostrum and milk and their related effects on offspring performance and gut microbiota. The first study showed that decreasing the level of hemicelluloses (HCs) in sow’s lactation diet increased the proportion of butyrate and the concentration of volatile fatty acids (VFAs), copper and threonine in milk. Simultaneously, the post-weaning growth of low birthweight piglets was improved, and the diarrhoea occurrence was reduced during the second week post-weaning. The second study showed that the level of HCs in the diet of lactating sows affected their faecal microbiota, modified the VFA profile in sow’s faeces during lactation and barely impacted the faecal microbiota of slow and fast growing piglets. The third study showed that replacing a source soluble DFs by one of insoluble DFs in sow’s diet during late gestation and lactation reduced farrowing duration, increased total VFAs and lactoferrin concentrations in colostrum, improved growth performance from birth to 1 day of lactation, during the post-weaning period and throughout the study, and reduced diarrhoea occurrence during the first week post-weaning. Finally, a fourth study proposed a workflow to analyse low biomass samples from the umbilical cord blood aiming at investigating the existence of a pre-birth microbiota with no substantial findings to confirm this hypothesis. Overall, the results of these studies confirmed that, besides the level of DFs, the sources, and the types of DFs included in the sow's diet shape the sow's microbiota, influence the composition of colostrum and milk, and improve offspring performance, but with limited impacts on the microbiota of piglets.

Pathogenetic mechanisms of gastrointestinal symptoms in a mouse model of Fabry disease: insights on the microbiota-gut-brain axis

Fabry disease (FD), X-linked metabolic disorder caused by a deficiency in α-galactosidase A activity, leads to the accumulation of glycosphingolipids, mainly Gb3 and lyso-Gb3, in several organs. Gastrointestinal (GI) symptoms are among the earliest and most common, strongly impacting patients’ quality of life. However, the origin of these symptoms and the exact mechanisms of pathogenesis are still poorly understood, thus the pressing need to improve their knowledge. Here we aimed to evaluate whether a FD murine model (α-galactosidase A Knock-Out) captures the functional GI issues experienced by patients. In particular, the potential mechanisms involved in the development and maintenance of GI symptoms were explored by looking at the microbiota-gut-brain axis involvement. Moreover, we sought to examine the effects of lyso-Gb3 on colonic contractility and the intestinal epithelium and the enteric nervous system, which together play important roles in regulating intestinal ion transport and fluid and electrolyte homeostasis. Fabry mice revealed visceral hypersensitivity and a diarrhea-like phenotype accompanied by anxious-like behavior and reduced locomotor activity. They reported also an imbalance of SCFAs and an early compositional and functional dysbiosis of the gut microbiota, which partly persisted with advancing age. Moreover, overexpression of TRPV1 was found in affected mice, and partial alteration of TRPV4 and TRPA1 as well, identifying them as possible therapeutic targets. The Ussing chamber results after treatment with lyso-Gb3 showed an increase in Isc (likely mediated by HCO3- ions movement) which affects neuron-mediated secretion, especially capsaicin- and partly veratridine-mediated. This first characterization of gut-brain axis dysfunction in FD mouse provides functional validation of the model, suggesting new targets and possible therapeutic approaches. Furthermore, lyso-Gb3 is confirmed to be not only a marker for the diagnosis and follow-up of FD but also a possible player in the alteration of the FD colonic ion transport process.