1,153 research outputs found

    Polypeptides and proteins that influence beer foam quality and analytical methods used in their study

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    POLYPEPTIDES AND PROTEINS THAT INFLUENCE BEER FOAM QUALITY AND ANALYTICAL METHODS USED IN THEIR STUDY A review of polypeptides and proteins that influence, direct or indirectly, beer foam quality, as well as the most relevant analytical methods used in their study, are presented. Protein Z, LTP1 and hordein/glutelin fragments originated from malt have a direct influence on beer foam quality. Other proteins, like malt hordeins and albumins and wheat puroindolines, are, to some degree, also important for beer foam quality. Protein hydrophobicity is pointed out as a key parameter to enhance foam quality. Electrophoretic, chromatographic and immunological analytical methods are currently used to study polypeptides and proteins present in barley, malt, wort, beer, and foam. Best results are obtained when combinations of these methods are applied

    Microbiological, biochemical and biogenic amine profiles of Terrincho cheese manufactured in several dairy farms

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    Terrincho is a Portuguese traditional cheese, bearing a protected denomination of origin (PDO) status, which is manufactured from raw ewes’ milk and ripened for a minimum period of 30 d. The objectives of this research effort were to characterize the microbiological and biochemical profiles of this cheese, manufactured in several dairy farms during the winter cheesemaking season (December through March), and establish tentative correlations between these profiles and formation of biogenic amines. For this goal, 29 cheeses from five batches, manufactured in as many dairy farms located throughout the PDO region, were analysed. The viable numbers of the total (mesophilic) microflora, enterococci, lactococci, lactobacilli, enterobacteria, staphylococci, pseudomonads, yeasts and moulds were determined by 30 d, following classical plate counting on specific media. Free amino acid and biogenic amine contents were determined by reverse-phase high-pressure liquid chromatography. The concentration of biogenic amines correlated well with microbial viable numbers, in both qualitative and quantitative terms; significant correlations were observed between enterococci and phenylethylamine (r ¼ 0.868, po0.0001), and between lactococci and cadaverine (r = 0.646, p <0.002) and tyramine (r = 0.868, p<0.0001). On the other hand, 220 g of Terrincho cheese would have to be consumed at a given time if the threshold of worst case risk was to be attained, which appears unrealistic for a typically single-doses meal ingredient. This study has contributed to deepen the knowledge on the microbiological and biochemical features of a unique Portuguese cheese throughout ripening, and to rationalize its safe consumption in terms of biogenic amines

    Assessment of paracetamol toxic effects under varying seawater pH conditions on the marine polychaete hediste diversicolor using biochemical endpoints

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    Increasing atmospheric carbon dioxide (CO2) levels are likely to lower ocean pH values, after its dissolution in seawater. Additionally, pharmaceuticals drugs are environmental stressors due to their intrinsic properties and worldwide occurrence. It is thus of the utmost importance to assess the combined effects of pH decreases and pharmaceutical contamination, considering that their absorption (and effects) are likely to be strongly affected by changes in oceanic pH. To attain this goal, individuals of the marine polychaete Hediste diversicolor were exposed to distinct pH levels (8.2, 7.9, and 7.6) and environmentally relevant concentrations of the acidic drug paracetamol (PAR: 0, 30, 60, and 120 µg/L). Biomarkers such as catalase (CAT), glutathione S-transferases (GSTs), acetylcholinesterase (AChE), and cyclooxygenase (COX) activities, as well as peroxidative damage (through thiobarbituric acid reactive substance (TBARS) quantification), were quantified to serve as ecotoxicological endpoints. Data showed a general increase in CAT and a decrease in GST activities (with significant fluctuations according to the tested conditions of PAR and pH). These changes are likely to be associated with alterations of the redox cycle driven by PAR exposure. In addition, pH levels seemed to condition the toxicity caused by PAR, suggesting that the toxic effects of this drug were in some cases enhanced by more acidic conditions. An inhibition of AChE was observed in animals exposed to the highest concentration of PAR, regardless of the pH value. Moreover, no lipid peroxidation was observed in most individuals, although a significant increase in TBARS levels was observed for polychaetes exposed to the lowest pH. Finally, no alterations of COX activities were recorded on polychaetes exposed to PAR, regardless of the pH level. The obtained results suggest that seawater acidification is detrimental to marine wildlife, since it may enhance toxic effects caused by environmental realistic concentrations of acidic drugs, such as PAR. This work was crucial to evidence that ocean acidification, in the context of a global change scenario of increased levels of both atmospheric and oceanic CO2, is a key factor in understanding the putative enhanced toxicity of most pharmaceutical drugs that are of an acidic nature.info:eu-repo/semantics/publishedVersio

    The improved quality of gluten-free bread due to the use of flaxseed oil cake: A comprehensive study evaluating nutritional value, technological properties, and sensory quality

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    The development of gluten-free bakery products, the quality of which is comparable to the quality of regular wheat-based products, remains a technological challenge. In this study, flaxseed oil cake (FOC), a by-product of flaxseed oil extraction and a source of nutritional and functional compounds, was used as an ingredient in the experimental bread formulation as partial replacement of starches (5%, 15%, and 30%). The gluten-free breads (GFBs) were evaluated for technological parameters, nutritional value, and sensory quality. Compared with the control, all FOC-enhanced GFBs were significantly (p < 0.05) richer in proteins, fat, and dietary fibre, with an increase that was proportional to the concentration of FOC in the formulation. At low-to-moderate levels (5% and 15%), FOC improved the specific volume, texture characteristics (reduced crumb hardness, gumminess, and chewiness), and appearance of GFBs, which allowed us to ameliorate its sensory features, but at 30% of FOC, the quality of the crumb texture decreased significantly (p < 0.005). Among the experimental GFBs, FOC15% exhibited improved technological characteristics and was rated by the sensory panel as the best in terms of overall quality. The results of the conducted research highlighted the benefits of incorporating FOC into GFB as a promising approach to developing a palatable, high-quality bakery product that may be a healthier option for individuals on a gluten-free diet, offering nutritional benefits. Nevertheless, it should be emphasised that the amount of FOC in GFB requires careful regulation.info:eu-repo/semantics/publishedVersio

    Upcycling rocha do Oeste pear pomace as a sustainable food ingredient: composition, rheological behavior and microstructure alone and combined with yeast protein extract

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    This work explores the potential of Rocha do Oeste pear pomace to be used as a sustainable and healthy food ingredient. Moreover, the enrichment with yeast protein extract (YPE) may be useful to design innovative food products. The main goals of this study were to assess pear pomace concerning: (i) chemical composition and antioxidant capacity; (ii) rheology, texture, and microstruc- ture characterization (alone or enriched with YPE), before and after heating. The results showed that pear pomace was a rich source of dietary fibers (74.5% DW), with phenolic compounds (3.9 mg chlorogenic acid equivalents/g dry weight), also presenting antiradical activity (3.90 μmol Trolox equivalents/g DW). Pear pomace showed a shear thinning behavior and a typical soft-gel behavior, which was not affected by YPE enrichment, thus suggesting that YPE did not affect pear pomace technological properties. Thermal treatment also did not alter pear pomace rheological properties. YPE addition induced a decrease in the apparent viscosity and a destabilizing effect, compared to the samples that were subjected to thermal processing. These results highlight the importance of pear pomace and the use of YPE for protein enrichment, opening new opportunities for their exploitationinfo:eu-repo/semantics/publishedVersio

    Preclinical pharmacokinetics and biodistribution of anticancer dinuclear Palladium(II)-Spermine Complex (Pd2Spm) in mice

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    Palladium-based compounds are regarded as potential analogs to platinum anticancer drugs with improved properties. The present study assessed the pharmacokinetics and biodistribution of a dinuclear palladium(II)-spermine chelate (Pd2Spm), which has previously been shown to possess promising in vitro activity against several therapy-resistant cancers. Using inductively coupled plasma-mass spectrometry, the kinetic profiles of palladium/platinum in serum, serum ultrafiltrate and tissues (kidney, liver, brain, heart, lungs, ovaries, adipose tissue and mammary glands) were studied in healthy female Balb/c mice after a single intraperitoneal bolus injection of Pd2Spm (3 mg/kg bw) or cisplatin (3.5 mg/kg bw) between 0.5 and 48 h post-injection. Palladium in serum exhibited biphasic kinetics with a terminal half-life of 20.7 h, while the free palladium in serum ultrafiltrate showed a higher terminal half-life than platinum (35.5 versus 31.5 h). Palladium was distributed throughout most of the tissues except for the brain, with the highest values in the kidney, followed by the liver, lungs, ovaries, adipose tissue and mammary glands. The in vitro cellular accumulation was also evaluated in breast cancer cells, evidencing a passive diffusion as a mechanism of Pd2Spm’s cellular entry. This study reports, for the first time, the favorable pharmacokinetics and biodistribution of Pd2Spm, which may become a promising pharmacological agent for cancer treatmentinfo:eu-repo/semantics/publishedVersio

    Bisphenol A migration from plastic materials: direct insight of ecotoxicity in Daphnia magna

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    Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) whose migration from food packaging is recognized worldwide. However, the real overall food contamination and related consequences are yet largely unknown. Among humans, children’s exposure to BPA has been emphasized because of the immaturity of their biological systems. The main aim of this study was to assess the reproductive impact of BPA leached from commercially available plastic containers used or related to child nutrition, performing ecotoxicological tests using the biomonitoring species Daphnia magna. Acute and chronic tests, as well as single and multigenerational tests were done. Migration of BPA from several baby bottles and other plastic containers evaluated by GC-MS indicated that a broader range of foodstuff may be contaminated when packed in plastics. Ecotoxicological test results performed using defined concentrations of BPA were in agreement with literature, although a precocious maturity of daphnids was detected at 3.0 mg/L. Curiously, an increased reproductive output (neonates per female) was observed when daphnids were bred in the polycarbonate (PC) containers (145.1±4.3 % to 264.7±3.8 %), both in single as in multigenerational tests, in comparison with the negative control group (100.3±1.6 %). A strong correlated dose-dependent ecotoxicological effect was observed, providing evidence that BPA leached from plastic food packaging materials act as functional estrogen in vivo at very low concentrations. In contrast, neonate production by daphnids cultured in polypropylene and non-PC bottles was slightly but not significantly enhanced (92.5±2.0 % to 118.8±1.8 %). Multigenerational tests also revealed magnification of the adverse effects, not only on fecundity but also on mortality, which represents a worrying trend for organisms that are chronically exposed to xenoestrogens for many generations. Two plausible explanations for the observed results could be given: a non-monotonic dose–response relationship or a mixture toxicity effect

    Influence of mixtures of acenaphthylene and benzo[a] anthracene on their degradation by Pleurotus ostreatus in sandy soil

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    Purpose Polycyclic aromatic hydrocarbons (PAHs) are a class of organic compounds commonly found as soil contaminants. Fungal degradation is considered as an environmentally friendly and cost-effective approach to remove PAHs from soil. Acenaphthylene (Ace) and Benzo[a]anthracene (BaA) are two PAHs that can coexist in soils; however, the influence of the presence of each other on their biodegradation has not been studied. The biodegradation of Ace and BaA, alone and in mixtures, by the white rot fungus Pleurotus ostreatus was studied in a sandy soil. Materials and methods Experimental microcosms containing soil spiked with different concentrations of Ace and BaAwere inoculated with P. ostreatus. Initial (t 0) and final (after 15 days of incubation) soil concentrations of Ace and BaA were determined after extraction of the PAHs. Results and discussion P. ostreatus was able to degrade 57.7% of the Ace in soil spiked at 30 mg kg−1 dry soil and 65.8% of Ace in soil spiked at 60 mg kg−1 dry soil. The degradation efficiency of BaA by P. ostreatus was 86.7 and 77.4% in soil spiked with Ace at 30 and 60 mg kg−1 dry soil, respectively. After 15 days of incubation, there were no significant differences in Ace concentration between soil spiked with Ace and soil spiked with Ace + BaA, irrespective of the initial soil concentration of both PAHs. There were also no differences in BaA concentration between soil spiked with BaA and soil spiked with BaA + Ace. Conclusions The results indicate that the fungal degradation of Ace and BaA was not influenced by the presence of each other’s PAH in sandy soil. Bioremediation of soils contaminated with Ace and BaA using P. ostreatus is a promising approach to eliminate these PAHs from the environment

    Nutritional characterization of Strychnos madagascariensis fruit flour produced by Mozambican communities and evaluation of Its contribution to nutrient adequacy

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    The indigenous fruit Strychnos madagascariensis is usually processed to flour, called nfuma, being highly consumed during staple food shortage. This study aimed to evaluate the nutritional composition of nfuma and its nutrient adequacy. Flours from four districts of Mozambique were analyzed using AOAC methods for proximate composition, HPLC for sugar, amino acids (AA), vitamin E and carotenoids and ICP-MS and FAAS for minerals. The results showed that nfuma stands out for its high content of fat (26.3–27.8%), mainly oleic acid, fiber (>6%), vitamin E (6.7 to 8.0 mg/100 g) and carotenes (2.2 to 2.6 mg/100 g). The main amino acids of nfuma protein were Arg, Asp and Glu, and Lys was the limiting one. The mineral composition reveals K (~1200 to 1700 mg/100 g) as the main macromineral followed by Mg > Ca > Na. The main trace element was Mn (~4 mg/100 g) followed by Fe > Zn > Cu > Cr > Co. Aluminum (~3 mg/100 g) was the main non-essential element and Rb, Ni, Sr, Ba, V, Cd were also quantified. Assuming the daily consumption of 50 g, nfuma provides 82% of Vitamin A dietary reference value for toddlers, while the consumption of 100 g contributes to 132% and 60% of Mn and vitamin A DRV for adults, respectively. Despite the nutritional advantages of nfuma, this flour can be a source of Ni, highlighting the importance of the study of good practices in its preparation to decrease the exposure to non-essential elements.info:eu-repo/semantics/publishedVersio

    Estresse ocupacional e satisfação dos usuários com os cuidados de saúde primários em Portugal

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    The Portuguese primary healthcare sector has suffered changes due to a reform on the lines of the conceptual framework referred to by some authors as "New Public Management." These changes may be generating higher levels of occupational stress with a negative impact at individual and organizational levels. This study examines the experience of stress in 305 health professionals (physicians, nurses and clinical secretaries) and satisfaction with the services provided by them from 392 users. The population under scrutiny is taken from 10 type A and 10 type B Family Health Units (FHU). The results show that 84.2% of professionals report moderate to high levels of occupational stress with the nurses being those with higher levels. Users reported good levels of satisfaction, especially with the nursing services. There were no differences in stress level between type A and type B FHU, though there were at the level of user satisfaction of type B FHU users who show higher levels of satisfaction. It was seen that dimensions of user satisfaction were affected by stress related to excess work.info:eu-repo/semantics/publishedVersio
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