89 research outputs found
Role of p-Coumaric Acid and Micronutrients in Sulfur Dioxide Tolerance in Brettanomyces bruxellensis
Sulfite is a common preservative in wine, but the spoilage yeast Brettanomyces bruxellensis
can produce volatile phenols even with the recommended sulfite dose. The purpose of this study
was to examine how wine components, p-coumaric acid (a precursor of volatile phenols), and
micronutrients influence culturability, viability, and volatile phenols production by B. bruxellensis
under sulfite stress. In red wine, a high sulfite dose (potassium metabisulfite, 100 mg L1) led to
an immediate death phase followed by growth recovery after two weeks. However, 4-ethylphenol
(4-EP) was continuously produced by dead or nonculturable cells. Nonetheless, an event of growth
recovery could not be observed in the case of the model wine. However, when the model wine was
supplemented with minerals and vitamins, both growth recovery and 4-EP production were noticed,
suggesting that the minerals and vitamins played an important role in maintaining the viability of
cells under the sulfite stress. The yeast could also utilize the p-coumaric acid (p-CA) as an energy
source, showing a specific growth rate of 0.0142 h1 with 1 mM of p-CA in model wine. Furthermore,
the sulfite-stressed cells exhibited ATP production by means of proton efflux while utilizing the p-CA.
This work highlights the novel finding that the conversion of p-CA into 4-EP provides sufficient
energy for the cell to remain metabolically active under the sulfite stress.info:eu-repo/semantics/publishedVersio
Relação entre a sintomatologia psicopatológica, adesão ao tratamento e qualidade de vida na infecção pelo HIV e Aids = Relationship among psychopathological symptoms, treatment adherence and quality of life in HIV/AIDS Infection
O presente estudo observou a existência de relações significativas entre sintomatologia psicopatológica (BSI), adesão ao tratamento (CEAT-VIH) e qualidade de vida (WHOQOL-Bref) em 125 pessoas HIV-positivo/AIDS em tratamento antirretroviral, atendidos em um hospital do Porto (Portugal). A sintomatologia psicopatológica correlacionou-se negativamente com adesão ao tratamento e qualidade de vida, e a adesão ao tratamento associou-se positivamente com a qualidade de vida. O modelo preditor de adesão ao tratamento, mediante análise de regressão múltipla, incluiu a ausência de sintomatologia psicopatológica, o comportamento de retirada dos medicamentos na farmácia hospitalar e a presença de efeitos colaterais do tratamento (R² =0,30). Ademais, observou-se um efeito mediador de sintomatologia psicopatológica entre a adesão ao tratamento e a qualidade de vida das pessoas com HIV/AIDS.The study shows evidence of statistical association among psychopathological symptoms (BSI), treatment adherence (CEAT-VIH) and quality of life (WHOQOL-Bref) in 125 HIV-positive/AIDS patients followed at Porto Hospital (Portugal). The psychopathological symptoms present a negative correlation with treatment adherence and quality of life. On the other hand, adherence was positively correlated with quality of life. The model of adherence to the antiretroviral treatment using multiple regression analysis includes absence of psychopathological symptoms, an adherence behavior (i.e. to get the medication at the hospital's pharmacy) and the experience of side effects because of medication (R² = 0.30). Besides, psychopathological symptoms have a mediation effect between adherence and quality of life in people with HIV/AIDS
Innovative and Healthier Dairy Products through the Addition of Microalgae: A Review
ReviewIn recent years, the development of healthier foods, richer in nutraceutical or functional
compounds, has been in great demand. Microalgae are attracting increasing attention, as their
incorporation in foods and beverages can be a promising strategy to develop sustainable foods with
improved nutritional profiles and a strong positive impacts on health. Despite the increasing market
demand in plant-based foods, the popularity of fermented dairy foods has increased in the recent
years since they are a source of microorganisms with health-promoting effects. In this context, the
incorporation of microalgae in cheeses, fermented milks and other dairy products represents an
interesting approach towards the development of innovative and added-value hybrid products based
on animal proteins and enriched with vegetable origin ingredients recognized as extremely valuable
sources of bioactive compounds. The effect of the addition of microalgal biomass (Chlorella vulgaris,
Arthrospira platensis, Pavlova lutheri, and Diacronema vlkianum, among others) and its derivates on the
physicochemical composition, colorimetric and antioxidant properties, texture and rheology behavior,
sensory profile, and viability of starter cultures and probiotics in yogurt, cheese and ice cream is
discussed in the current work. This review of the literature on the incorporation of microalgae in
dairy products aims to contribute to a better understanding of the potential use of these unique food
ingredients in the development of new sustainable products and of their beneficial effects on health.
Considering the importance of commercialization, regulatory issues about the use of microalgae in
dairy products are also discussedinfo:eu-repo/semantics/publishedVersio
Development and physicochemical characterization of a new grass pea (Lathyrus sativus L.) miso
BACKGROUND: Western consumers interest in Eastern fermented foods has been growing, due to their nutritional and healthy
properties. In this study, new sweet misos and salty misos were produced using grass pea (Lathyrus sativus L.) – traditional Portuguese
legume from local producers – to promote its consumption and preservation. The evolution of the new misos was evaluated
in comparison to traditional miso (made from soybean), through analysis of the chemical composition, colour, texture
and linear viscoelastic behaviour.
RESULTS: Throughout the fermentation process, the ascorbic acid and phenolic compounds content – with important nutritional
value – increased in all misos, mainly in misos produced using grass pea, besides, grass pea sweet miso presented the
fastest evolution and darkest colour. The texture parameters (firmness and adhesiveness) of misos decreased over time: grass
pea sweet miso showed the highest firmness reduction (51.63 N to 6.52 N) and soybean sweet miso the highest adhesiveness
reduction (27.76 N to 3.11 N). Viscoelastic moduli also decreased, reflecting a reduction in the degree of internal structuring for
all misos. However, grass pea misos presented more structured internal systems with faster maturation kinetics than soybean
misos, for which stabilization started earlier.
CONCLUSION: Two innovative misos were developed from grass pea. After 4 months, the texture parameters and viscoelastic
moduli for grass pea misos, were similar to the control misos made from soybean, showing that grass pea can be used as a
raw material to produce a sustainable miso with potentially healthy propertiesinfo:eu-repo/semantics/publishedVersio
Wine spoilage control: impact of Saccharomycin on Brettanomyces bruxellensis and its conjugated effect with sulfur dioxide
The yeast Brettanomyces bruxellensis is one of the most dangerous wine contaminants due
to the production of phenolic off-flavors such as 4-ethylphenol. This microbial hazard is regularly
tackled by addition of sulfur dioxide (SO2). Nevertheless, B. bruxellensis is frequently found at low
levels (ca 103 cells/mL) in finished wines. Besides, consumers health concerns regarding the use of
sulfur dioxide encouraged the search for alternative biocontrol measures. Recently, we found that
Saccharomyces cerevisiae secretes a natural biocide (saccharomycin) that inhibits the growth of different
B. bruxellensis strains during alcoholic fermentation. Here we investigated the ability of S. cerevisiae
CCMI 885 to prevent B. bruxellensis ISA 2211 growth and 4-ethylphenol production in synthetic
and true grape must fermentations. Results showed that B. bruxellensis growth and 4-ethylphenol
production was significantly inhibited in both media, although the effect was more pronounced
in synthetic grape must. The natural biocide was added to a simulated wine inoculated with
5 x 10 2 cells/mL of B. bruxellensis, which led to loss of culturability and viability (100% dead cells at
day-12). The conjugated effect of saccharomycin with SO2 was evaluated in simulated wines at 10,
12, 13 and 14% (v/v) ethanol. Results showed that B. bruxellensis proliferation in wines at 13 and 14%
(v/v) ethanol was completely prevented by addition of 1.0 mg/mL of saccharomycin with 25 mg/L of
SO2, thus allowing to significantly reduce the SO2 levels commonly used in wines (150–200 mg/L)info:eu-repo/semantics/publishedVersio
Grapevine aquaporins: gating of a tonoplast intrinsic protein (TIP2; 1) by cytosolic pH
Grapevine (Vitis vinifera L.) is one of the oldest and most important perennial crops being considered as a fruit ligneous tree
model system in which the water status appears crucial for high fruit and wine quality, controlling productivity and alcohol
level. V. vinifera genome contains 28 genes coding for aquaporins, which acting in a concerted and regulated manner
appear relevant for plant withstanding extremely unfavorable drought conditions essential for the quality of berries and
wine. Several Vv aquaporins have been reported to be expressed in roots, shoots, berries and leaves with clear cultivar
differences in their expression level, making their in vivo biochemical characterization a difficult task. In this work V. vinifera
cv. Touriga nacional VvTnPIP1;1, VvTnPIP2;2 and VvTnTIP2;1 were expressed in yeast and water transport activity was
characterized in intact cells of the transformants. The three aquaporins were localized in the yeast plasma membrane but
only VvTnTIP2;1 expression enhanced the water permeability with a concomitant decrease of the activation energy of water
transport. Acidification of yeast cytosol resulted in loss of VvTnTIP2;1 activity. Sequence analysis revealed the presence of a
His131 residue, unusual in TIPs. By site directed mutagenesis, replacement of this residue by aspartic acid or alanine resulted
in loss of pHin dependence while replacement by lysine resulted in total loss of activity. In addition to characterization of
VvTn aquaporins, these results shed light on the gating of a specific tonoplast aquaporin by cytosolic pHinfo:eu-repo/semantics/publishedVersio
Molecular and functional characterization of grapevine NIPs through heterologous expression in aqy-null Saccharomyces cerevisiae
Plant Nodulin 26-like Intrinsic Proteins (NIPs) are multifunctional membrane channels
of the Major Intrinsic Protein (MIP) family. Unlike other homologs, they have low intrinsic water
permeability. NIPs possess diverse substrate selectivity, ranging from water to glycerol and to
other small solutes, depending on the group-specific amino acid composition at aromatic/Arg (ar/R)
constriction. We cloned three NIPs (NIP1;1, NIP5;1, and NIP6;1) from grapevine (cv. Touriga
Nacional). Their expression in the membrane of aqy-null Saccharomyces cerevisiae enabled their
functional characterization for water and glycerol transport through stopped-flow spectroscopy.
VvTnNIP1;1 demonstrated high water as well as glycerol permeability, whereas VvTnNIP6;1 was
impermeable to water but presented high glycerol permeability. Their transport activities were
declined by cytosolic acidification, implying that internal-pH can regulate NIPs gating. Furthermore,
an extension of C-terminal in VvTnNIP6;1M homolog, led to improved channel activity, suggesting
that NIPs gating is putatively regulated by C-terminal. Yeast growth assays in the presence of diverse
substrates suggest that the transmembrane flux of metalloids (As, B, and Se) and the heavy metal (Cd)
are facilitated through grapevine NIPs. This is the first molecular and functional characterization of
grapevine NIPs, providing crucial insights into understanding their role for uptake and translocation
of small solutes, and extrusion of toxic compounds in grapevineinfo:eu-repo/semantics/publishedVersio
Clean Label “Rocha” Pear (Pyrus communis L.) Snack Containing Juice By-Products and Euglena gracilis Microalgae
Original Research“Rocha do Oeste” pear is a Portuguese Protected Designation of Origin variety and
one of the country’s most relevant fruits for its nutritional value, production area, and
exportation amounts. The recent integration of a pilot-scale juice production line brought
to SUMOL+COMPAL company the need to characterize the new resulting fractions and
value the new by-products. The objective of this work was to value the juice clarification
by-products, producing a clean label and fiber-rich snack, in a circular economy rationale,
where the secondary products are upcycled back into the food value chain, by creating
another food product that includes those by-products. For the above to be possible,
the laboratory conditions to produce pear fractions were optimized. After optimizing the
puree centrifugation, using response surface methodology (RSM), and optimizing the
turbid juice crossflow filtration, the different fractions were characterized in rheological,
nutritional, and physical aspects. Comparison to the pulps revealed an increase in the
viscosity of the pomace; an enriching effect on the fructose, glucose, and dietary fiber
levels in the pomace, and maintenance of the vitamin C levels after centrifugation; and
with no effect on the contents of total phenols during the filtration step. A thick pear
snack was developed, incorporating retained fraction, inulin, and Euglena gracilis in the
pomace, and optimized regarding its firmness and dietary fiber content. The snack
characterization revealed an interesting total phenols content (which was maintained
from the raw materials). Compared to the snack without microalgae and a commercial
fruit snack, the pear snack with E. gracilis was well-accepted by the sensory panel,
mainly in texture and appearance, and can be further improved in aroma and flavor.
The snack without microalgae was the favorite among the three samples, in most
sensory parameters, and never got the answer “I’m sure I wouldn’t buy it.” Therefore,
an innovative, clean label and plant-based snack was developed, in a circular economy
rationale, which was relatively well-appreciated by the panel. This snack is rich in dietary
fiber, having the possibility of presenting various nutritional claims, and the potential for
easy sensory optimizationinfo:eu-repo/semantics/publishedVersio
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