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- Detection of the crystallization process of paracetamol with a multi-mode optical fiber in a reflective configurationPublication . Soares, Liliana; Novais, Susana; Ferreira, António; Frazão, Orlando; Silva, SusanaA configuration of a refractometer sensor is described with the aim of optically detecting the crystallization process of paracetamol. The developed sensing head is based on a conventional cleaved multi-mode fiber. The fiber tip sensor structure was submitted to contact with the liquid of interest (paracetamol fully dissolved in 40% v/v of ethanol/water) and the crystallization process of paracetamol, induced with continued exposure to air, was monitored in real time.
- Microinmuno fluorescencia para el diagnóstico de enfermedades infecciosasPublication . Pérez, Rodríguez; Mireya, Abreu; Mazzali, WaardLa infección por Chlamydia pneumoniae se produce en todo el mundo, lo que da como resultado una prevalencia del 40-90% de anticuerpos séricos contra la especie en diversas poblaciones. La serología es la herramienta de diagnóstico más utilizada para la detección de infecciones respiratorias por clamidia en la práctica clínica habitual. El principal problema de este estudio es la validez de las pruebas utilizadas, especialmente el nuevo rDNA LPS ELISA.
- Volatile profile in goat coalho cheese supplemented with probiotic lactic acid bacteriaPublication . Bezerra, Taliana Kenia Alves; Arcanjo, Narciza Mari de Oliveira; Araújo, Ana Rita Ribeiro de; Queiroz, Angela Lima Meneses de; Oliveira, Maria Elieidy Gomes de; Gomes, Ana Maria Pereira; Madruga, Marta SuelyThe aim of this study was to evaluate the aromatic profiles of both traditional goat Coalho cheese and cheeses added with isolated and combined probiotics, during 28 days of storage. The cheeses were named as follows: C, with Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris; L, with Lactobacillus acidophilus; P, with Lactobacillus paracasei; B, with Bifidobacterium lactis; and M, a “mixed” culture with the three probiotic microorganisms. Based on the results, it was verified that both the use of different cultures of probiotic lactic bacteria and the length of storage affect the volatile profile. The length of storage had the most influence on the number of volatiles produced. A total of twenty five aromatic compounds were identified in the goat cheese; of these twenty five, there were six alcohols, four hydrocarbons, four terpenes, three acids, three ketones, three aldehydes and two esters. Esters and ketones can have a positive influence on goat Coalho cheese, since their pleasant aroma can help minimize other undesirable odours.
- The impact of single amino acids on growth and volatile aroma production by Saccharomyces cerevisiae strainsPublication . Fairbairn, Samantha; McKinnon, Alexander; Musarurwa, Hannibal T.; Ferreira, António C.; Bauer, Florian F.Nitrogen availability and utilization by Saccharomyces cerevisiae significantly influence fermentation kinetics and the production of volatile compounds important for wine aroma. Amino acids are the most important nitrogen source and have been classified based on how well they support growth. This study evaluated the effect of single amino acids on growth kinetics and major volatile production of two phenotypically different commercial wine yeast strains in synthetic grape must. Four growth parameters, lag phase, maximum growth rate, total biomass formation and time to complete fermentation were evaluated. In contrast with previous findings, in fermentative conditions, phenylalanine and valine supported growth well and asparagine supported it poorly. The four parameters showed good correlations for most amino acid treatments, with some notable exceptions. Single amino acid treatments resulted in the predictable production of aromatic compounds, with a linear correlation between amino acid concentration and the concentration of aromatic compounds that are directly derived from these amino acids. With the increased complexity of nitrogen sources, linear correlations were lost and aroma production became unpredictable. However, even in complex medium minor changes in amino acid concentration continued to directly impact the formation of aromatic compounds, suggesting that the relative concentration of individual amino acids remains a predictor of aromatic outputs, independently of the complexity of metabolic interactions between carbon and nitrogen metabolism and between amino acid degradation and utilization pathways.
- Studying haloanisoles interaction with olfactory receptorsPublication . Teixeira, Carla S. Silva; Ferreira, António César Silva; Cerqueira, Nuno M. F. S. A.In this paper, computational means were used to explain and predict the interaction of several odorant molecules, including three haloanisoles, 2,4,6-trichloroanisole (TCA), 2,4,6-tribromoanisole (TBA), and 2,4,6-trichlorophenol (TCP), with three olfactory receptors (ORs): OR1A1, OR1A2, and OR3A1. As the X-ray structure of these ORs is not known, the three-dimensional structure of each OR was modeled by homology modeling. The structures of these ORs were stabilized by molecular dynamic simulations and the complexes of the odorant molecules with each ORs were generated by molecular docking. The theoretical results have shown that each OR has distinct but well-defined binding regions for each type of odorant molecules (aldehydes and alcohols). In OR3A1, the aldehydes bind in the bottom region of the binding pocket nearby Ser257 and Thr249. In the paralogues OR1A1 and OR1A2, the aldehydes tend to interact in the top region of the binding pocket and close to a positively charged lysine. On the other hand, the alcohols interact in the bottom region of the active site and close to a negatively charged aspartate. These results indicate that when aldehydes and alcohols odorants compete in these two ORs, the aldehydes can block the access of the alcohols odorants to their specific binding site. This observation goes in line with the experimental data that reveals that when the odorant is an aldehyde, a lower quantity of ligand is needed to cause 50% of the maximum response (lower EC50), when compared with the alcohols. The theoretical results have also allowed to explain the differences in the activity of (S)-(−)-citronellol in the wild-type and mutated OR1A1. The theoretical results show that Asn109 has a preponderant role in this matter, since when it is mutated, it leads to a conformational rearrangement of the binding pocket that prevents the interaction of (S)-(−)-citronellol with Asp111 that was shown to be important for the OR activation. The good agreement between the theoretical and experimental results also lead us to study the potential interaction of the haloanisoles, TCA, TBA, and TCP with these ORs. The results have shown that these compounds can compete with other known agonists/antagonists for the access to the binding regions of ORs. These results may partially explain the capability of these compounds to give a musty odor to food and beverages at very low concentrations.
- Chemical and sensory study on the evolution of aromatic and nonaromatic compounds during the progressive oxidative storage of a Sauvignon blanc winePublication . Coetzee, Carien; Wyngaard, Elizma Van; Šuklje, Katja; Ferreira, António César Silva; Toit, Wessel J. duThe effect of repetitive controlled oxidation on the chemical and sensory composition of a fresh and fruity style Sauvignon blanc wine was investigated. Chemical analyses were conducted together with extensive sensory profiling. A decrease in volatile thiols responsible for the fruity nuances and an increase in oxidation-related compounds, such as acetaldehyde, during the course of the oxidation was observed. The wine evolved from a fresh and fruity one to one with slight oxidation and then developed extreme oxidative characteristics. The control samples (no oxygen added) developed a "cooked" character that could indicate the formation of "reductive" compounds in these wines. Conversely, the wines that received a single dose of oxygen did not develop this flavor and were perceived to be fresher and fruitier than the control samples. The color of the wine evolved before the disappearance of the pleasant aroma.
- High throughput analysis of integron gene cassettes in wastewater environmentsPublication . Gatica, Joao; Tripathi, Vijay; Green, Stefan; Manaia, Célia M.; Berendonk, Thomas; Cacace, Damiano; Merlin, Christophe; Kreuzinger, Norbert; Schwartz, Thomas; Fatta-Kassinos, Despo; Rizzo, Luigi; Schwermer, Carsten U.; Garelick, Hemda; Jurkevitch, Edouard; Cytryn, EddieIntegrons are extensively targeted as a proxy for anthropogenic impact in the environment. We developed a novel high-throughput amplicon sequencing pipeline that enables characterization of thousands of integron gene cassette-associated reads, and applied it to acquire a comprehensive overview of gene cassette composition in effluents from wastewater treatment facilities across Europe. Between 38 100 and 172 995 reads per-sample were generated and functionally characterized by screening against nr, SEED, ARDB and β-lactamase databases. Over 75% of the reads were characterized as hypothetical, but thousands were associated with toxin-antitoxin systems, DNA repair, cell membrane function, detoxification and aminoglycoside and β-lactam resistance. Among the reads characterized as β-lactamases, the carbapenemase blaOXA was dominant in most of the effluents, except for Cyprus and Israel where blaGES was also abundant. Quantitative PCR assessment of blaOXA and blaGES genes in the European effluents revealed similar trends to those displayed in the integron amplicon sequencing pipeline described above, corroborating the robustness of this method and suggesting that these integron-associated genes may be excellent targets for source tracking of effluents in downstream environments. Further application of the above analyses revealed several order-of-magnitude reductions in effluent-associated β-lactamase genes in effluent-saturated soils, suggesting marginal persistence in the soil microbiome.
- Characterization of TGF-β expression and signaling profile in the adipose tissue of rats fed with high-fat and energy-restricted dietsPublication . Sousa-Pinto, Bernardo; Gonçalves, Laura; Rodrigues, Adriana R.; Tomada, Inês; Almeida, Henrique; Neves, Delminda; Gouveia, Alexandra M.Transforming growth factor beta (TGF-β) plays an important role in the pathogenesis of obesity, influencing the release of inflammation mediators and promoting remodeling and collagen deposition in the adipose tissue (AT). In this context, this work aims to elucidate whether TGF-β and Smad-dependent or Smad-independent signaling pathways contribute to regional differentiation of AT in high-fat diet (HFD) and energy-restricted (ER) rat models. For this, TGF-β, TGF-β receptors I and II, PAI-1 and GLUT4 mRNA levels were quantified by real-time PCR, and western blotting assays allowed the semiquantification of TGF-β and proteins from Smad3, ERK1/2 and Akt signaling pathways in subcutaneous and visceral (epididymal, retroperitoneal and mesenteric) fat depots from control, HFD and ER-treated rats. HFD was associated to increased levels of TGF-β and PAI-1 mRNA in epididymal and retroperitoneal visceral fat depots, while ER diet induced a reduction of TGF-β mRNA levels in mesenteric, but surprisingly an increase in retroperitoneal fat. Regarding the different signaling pathways, contrarily to what was found for Smad3, activation of ERK1/2 and Akt in response to HFD was detected in all the visceral but not in subcutaneous fat depots. ER-treated rats presented a more heterogeneous signaling response, as well as decreased TGF-β receptors expression, in the different visceral fat depots. In conclusion, subcutaneous and visceral AT respond differently to distinct diet patterns regarding TGF-β expression and activated signaling pathways. Furthermore, the present study points that visceral AT should not be understood as a homogeneous entity since that response also varied in the different fat depots.
- Influence of the addition of Lactobacillus acidophilus La-05, Bifidobacterium animalis subsp. lactis Bb-12 and inulin on the technological, physicochemical, microbiological and sensory features of creamy goat cheesePublication . Barbosa, Ilsa C.; Oliveira, Maria E. G.; Madruga, Marta S.; Gullón, Beatriz; Pacheco, Maria T. B.; Gomes, Ana M. P.; Batista, Ana S. M.; Pintado, M. E.; Souza, Evandro L.; Queiroga, Rita C. R. E.The effects of the addition of Lactobacillus acidophilus LA-05, Bifidobacterium animalis subsp. lactis BB-12 and inulin on the quality characteristics of creamy goat cheese during refrigerated storage were evaluated. The manufactured cheeses included the addition of starter culture (Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris - R-704) (CC); starter culture, L. acidophilus LA-05 and inulin (CLA); starter culture, B. lactis BB-12 and inulin (CBB); or starter culture, L. acidophilus LA-05, B. lactis BB-12 and inulin (CLB). In the synbiotic cheeses (CLA, CBB and CLB), the counts of L. acidophilus LA-05 and B. lactis BB-12 were greater than 6log CFU g(-1), the amount of inulin was greater than 6 g per 100 g, and the firmness was reduced. The cheeses evaluated had high brightness values (L*), with a predominance of yellow (b*). CC had higher contents of proteins, lipids and minerals compared to the other cheeses. There was a decrease in the amount of short-chain fatty acids (SCFAs) and an increase of medium-chain (MCFAs) and long-chain fatty acids (LCFAs) in the synbiotic cheeses compared to CC. The amount of conjugated linoleic acid increased in CLA, CBB and CLB. The highest depth of proteolysis and the greatest changes in the release of free amino acids were found in CLB. The addition of inulin and probiotics, alone or in co-culture, did not affect the cheese acceptance. Inulin and probiotics can be used together for the production of creamy goat cheese without negatively affecting the general quality characteristics of the product, and to add value because of its synbiotic potential.
- Polyphenolic profile and antioxidant and antibacterial activities of monofloral honeys produced by Meliponini in the Brazilian semiarid regionPublication . Sousa, Janaína Maria; Souza, Evandro Leite de; Marques, Gilmardes; Meireles, Bruno; Cordeiro, Ângela Tribuzy de Magalhães; Gullón, Beatriz; Pintado, M. E.; Magnani, MarcianeThis study assessed the polyphenolic profile and the antioxidant and antibacterial activities ofmonofloral honeys produced by Meliponini in the Brazilian semiarid region. Honeys from Ziziphus joazeiro Mart. (juazeiro) and Croton heliotropiifolius Kunth (velame branco) showed the highest total phenolic contents (TPCs) and the greatest antioxidant activity in assays with DPPH and ABTS•+ radicals. Honeys from Mimosa quadrivalvis L. (malícia) presented the strongest anti-peroxyl activity in ORAC assay. Juazeiro honeys showed the highest quantities of trans-cinnamic, p-coumaric, ellagic and ferulic acids, as well as of catechin, rutin, hesperetin and chrysin when compared to the other honeys produced by the same bee species. Malícia honeys showed the greatest quantities of myricetin, quercetin and kaempferol among the studied honeys. Honeys with the highest TPCs presented the highest antimicrobial activity. The results showed the impact of the floral source on the polyphenolic profile as well as on the antioxidant and antimicrobial properties of Meliponini honeys.