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- Antimicrobial Susceptibility of Enterococci Isolated from Terrincho CheesePublication . Pimentel, L. L.; Novais, C.; Pintado, M. E.; Gomes, Ana M. P.; Coque, T.; Sousa, J. C; Malcata, F. Xavier; Peixe, L.
- Bioactive sugarcane lipids in a circular economy contextPublication . Teixeira, Francisca S.; Vidigal, Susana S.M.P.; Pimentel, Lígia L.; Costa, Paula T.; Pintado, Manuela E.; Rodríguez-Alcalá, Luís M.Most of the global sugar and ethanol supply trade comes from the harvesting of Saccharum officinarum (i.e., sugarcane). Its industrial processing results in numerous by-products and waste streams, such as tops, straw, filter cake, molasses and bagasse. The recovery of lipids (i.e., octacosanol, phytosterols, long-chain aldehydes and triterpenoids) from these residues is an excellent starting point for the development of new products for various application fields, such as health and well-being, representing an important feature of the circular economy. By selecting green scalable extraction procedures, industry can reduce its environmental impact. Refluxed ethanol extraction methods have been demonstrated to meet these characteristics. On the other hand, effective non-solvent methodologies such as molecular distillation and supercritical CO2 extraction can fractionate lipids based on high temperature and pressure application with similar yields. Sugarcane lipophilic extracts are usually analyzed through gas chromatography (GC) and liquid chromatography (LC) techniques. In many cases, the identification of such compounds involves the development of high-temperature GC–MS/FID techniques. On the other hand, for the identification and quantification of thermolabile lipids, LC–MS techniques are suitable for the separation and identification of major lipid classes. Generically, its composition includes terpenes, phytosterols, tocopherol, free fatty acids, fatty alcohols, wax esters, triglycerides, diglycerides and monoglycerides. These compounds are already known for their interesting application in various fields such as pharma and cosmetics due to their anti-hypercholesterolemic, anti-hyperglycemic, antioxidant and anti-inflammatory properties.
- Free fatty acids profiling in olive oil and olives from the Trás-os-Montes Portuguese regionPublication . Rodríguez-Alcalá, Luís M.; Correia, Inês F.; Pimentel, Lígia L; Pereira, José A; Gomes, Ana M.; Pintado, ManuelaOlive oil and olives are food products highly appreciated by consumers for both organoleptic (e.g. taste/ flavour) and technological properties (i.e. cooking). Moreover, during the last years several research works have also reported presence of phenols, tocopherols, squalene, sterols and fatty acids (e.g. oleic acid) with important positive health effects (e.g. anti-inflammatory, antiarrhythmic and vasodilatory) [1]. Although free fatty acids (FFA) in olive oil are an important quality parameter, this analysis is highly challenging as it involves isolation, fractionation and derivatization steps. Interestingly, some studies suggest that free polyunsaturated FA can be recognized by GPR120 receptors triggering anti- inflammatory processes [2]. Thus, a single-step method for the FFA analysis in both biological and foodstuffs was recently developed by authors of this current work [3]. The Portuguese region of Trás-os-Montes is an important producer of high quality olive oil and olives but to date, its FFA composition has been poorly studied. The detailed composition of such nutritional parameter would help increase the value of these products to promote the region and the producers. Therefore, different monovarietal olive oils of Cobrançosa (n=2), Madural (n=2), Verdeal (n=5) and Santulhana (n=6) were collected, in duplicate, directly from various local olive mills. Corresponding olive samples were also obtained. The procedure described by Matyash et al. [4] was used for lipid isolation. FFA in all samples were analyzed by GC-FID as fatty acid methyl esters (FAME) according to the above commented method of Pimentel et al. [3]. Olive oil and olives had the same qualitative composition and oleic acid was the main FFA as expected. Results showed intra-varietal differences that may be associated to location. When compared with olives, oil elaboration decreased the concentration of all FFA as expected, but homogenized the composition of the assayed oils.
- Impact of exposure to cold and cold-osmotic stresses on virulence-associated characteristics of Listeria monocytogenes strainsPublication . Alves, Ângela; Magalhães, Rui; Brandão, Teresa R. S.; Pimentel, Lígia; Rodríguez-Alcalá, Luis M.; Teixeira, Paula; Ferreira, VâniaThe objective of this work was to investigate the effect of stress conditions frequently encountered in food-associated environments on virulence-associated characteristics of eight strains of Listeria monocytogenes. Strains were grown at low (11 ºC, cold stress) and optimal (37 ºC) temperatures and in high NaCl concentrations (6% NaCl, 11 ºC; cold-osmotic stress) and tested for their ability to invade the human intestinal epithelial Caco-2 cells. Results demonstrate that the correlation between exposure to cold stress and increased invasion phenotype is strain-dependent as strains investigated exhibited different behaviours, i.e. exposure to cold stress conditions resulted in a significant increase of invasion levels in five out of the eight strains tested, when compared to growth under optimal conditions. On the other hand, when these cold-adapted cells were subsequently submitted to high salt concentrations and low temperature, their enhanced ability to invade Caco-2 was lost. Surprisingly, saturated fatty acids (SFA) and branched chain fatty acids (BCFA) decreased when L. monocytogenes were exposed to stress conditions as opposed to what has been observed in other studies, therefore highlighting that further studies will need to deepen in the understanding of the lipid metabolism of these strains. The effect of stress conditions on the survival of three selected L. monocytogenes strains through an in vitro gastrointestinal (GI) tract digestion model was further investigated. The exposure to cold-osmotic stress increased the survival of one strain through the GI tract.
- Study of virulence factors in Enterococci isolated from cheesePublication . Pimentel, L. L.; Semedo, T.; Gomes, Ana M. P.; Pintado, M. E.; Tenreiro, R.; Crespo, M. T. B.; Malcata, F. Xavier
- Acidifying and aromatic properties of enterococcus strains in ovine and bovine milksPublication . Pimentel, L. L.; Soares, J. C.; Pintado, M. E.; Pintado, Ana I. E.; Gomes, Ana M. P.; Ferreira, A. C.; Malcata, F. X.
- Lactobacillus mulieris sp. nov., a new species of Lactobacillus delbrueckii groupPublication . Rocha, Joana; Botelho, João; Ksiezarek, Magdalena; Ugarcina Perovic, Svetlana; Machado, Miguel; Carrico, João André; Pimentel, Lígia L.; Salsinha, Sofia; Rodríguez-Alcalá, Luis M.; Pintado, Manuela; Ribeiro, Teresa G.; Peixe, LuísaOne Gram-stain-positive, non-motile, non-spore-forming, catalase-negative, and coccobacilli-shaped strain, designated c10Ua161MT, was isolated from a urine sample from a reproductive-age healthy woman. Comparative 16S rRNA gene sequence analysis indicated that strain c10Ua161MT belonged to the genus Lactobacillus . Phylogenetic analysis based on pheS and rpoA gene sequences strongly supported a clade encompassing strains c10Ua161MT and eight other strains from public databases, distinct from currently recognized species of the genus Lactobacillus. In silico Average Nucleotide Identity (ANI) and Genome-to-Genome Distance Calculator (GGDC), showed 87.9 and 34.3 % identity to the closest relative Lactobacillus jensenii , respectively. The major fatty acids of strain c10Ua161MT were C18 : 1ω9c (65.0%), C16 : 0 (17.8%), and summed feature 8 (10.2 %; comprising C18 : 1ω7c, and/or C18 : 1ω6c). The DNA G+C content of the strains is 34.2 mol%. On the basis of data presented here, strain c10Ua161MT represents a novel species of the genus Lactobacillus , for which the name Lactobacillus mulieris sp. nov. is proposed. The type strain is c10Ua161MT (=CECT 9755T=DSM 108704T).
- Influence of shaking and viable cell numbers on microbial conjugated linoleic acid (CLA) productionPublication . Fontes, Ana Luiza; Pimentel, Lígia; Salsinha, Ana Sofia; Rodriguez, Juan Miguel; Domingues, MR; Rodríguez-Alcalá, Luís M.; Gomes, Ana Maria
- Suitable simple and fast methods for selective isolation of phospholipids as a tool for their analysisPublication . Pimentel, Lígia; Fontes, Ana Luiza; Salsinha, Sofia; Machado, Manuela; Correia, Inês; Gomes, Ana Maria; Pintado, Manuela; Rodríguez-Alcalá, Luis MiguelLipids are gaining relevance over the last 20 years, as our knowledge about their role has changed from merely energy/structural molecules to compounds also involved in several biological processes. This led to the creation in 2003 of a new emerging research field: lipidomics. In particular the phospholipids have pharmacological/food applications, participate in cell signalling/homeostatic pathways while their analysis faces some challenges. Their fractionation/purification is, in fact, especially difficult, as they are amphiphilic compounds. Moreover, it usually involves SPE or TLC procedures requiring specific materials hampering their suitableness for routine analysis. Finally, they can interfere with the ionization of other molecules during mass spectrometry analysis. Thus, simple high‐throughput reliable methods to selectively isolate these compounds based on the difference between chemical characteristics of lipids would represent valuable tools for their study besides that of other compounds. The current review work aims to describe the state‐of‐the‐art related to the extraction of phospholipids using liquid‐liquid methods for their targeted isolation. The technological and biological importance of these compounds and ion suppression phenomena are also reviewed. Methods by precipitation with acetone or isolation using methanol seem to be suitable for selective isolation of phospholipids in both biological and food samples.
- One health, fermented foods, and gut microbiotaPublication . Bell, Victoria; Ferrão, Jorge; Pimentel, Lígia; Pintado, Manuela; Fernandes, TitoChanges in present-day society such as diets with more sugar, salt, and saturated fat, bad habits and unhealthy lifestyles contribute to the likelihood of the involvement of the microbiota in inflammatory diseases, which contribute to global epidemics of obesity, depression, and mental health concerns. The microbiota is presently one of the hottest areas of scientific and medical research, and exerts a marked influence on the host during homeostasis and disease. Fermented foods and beverages are generally defined as products made by microbial organisms and enzymatic conversions of major and minor food components. Further to the commonly-recognized effects of nutrition on the digestive health (e.g., dysbiosis) and well-being, there is now strong evidence for the impact of fermented foods and beverages (e.g., yoghurt, pickles, bread, kefir, beers, wines, mead), produced or preserved by the action of microorganisms, on general health, namely their significance on the gut microbiota balance and brain functionality. Fermented products require microorganisms, i.e., Saccharomyces yeasts and lactic acid bacteria, yielding alcohol and lactic acid. Ingestion of vibrant probiotics, especially those contained in fermented foods, is found to cause significant positive improvements in balancing intestinal permeability and barrier function. Our guts control and deal with every aspect of our health. How we digest our food and even the food sensitivities we have is linked with our mood, behavior, energy, weight, food cravings, hormone balance, immunity, and overall wellness. We highlight some impacts in this domain and debate calls for the convergence of interdisciplinary research fields from the United Nations' initiative. Worldwide human and animal medicine are practiced separately; veterinary science and animal health are generally neither considered nor inserted within national or international Health discussions. The absence of a clear definition and subsequent vision for the future of One Health may act as a barrier to transdisciplinary collaboration. The point of this mini review is to highlight the role of fermented foods and beverages on gut microbiota and debate if the need for confluence of transdisciplinary fields of One Health is feasible and achievable, since they are managed by separate sectors with limited communication.