1,402 research outputs found
Effect of crop rotations soil quality, production, and economic returns of barley grown under zero till in Parana (Brazil)
Non-Peer ReviewedThe cereal growing area of southern Brazil is characterized by high intensity rainstorms, warm temperatures, hilly topography, and acid soils low in natural fertility. Traditionally, cereals are grown in winter in a double cropping system with soybeans grown in summer. These factors combined with excessive use of disc-type implements causes severe soil loss by water erosion, low grain yields due to disease and insects, and general soil degradation. The combined use of zero or minimum tillage with crop rotations which include other crop types is one solution being examined with assistance from CIDA and
involving scientists from Canada and Brazil. This paper reports on the agronomic and economic performance of four zero-till barley rotations. After four years of study, the results show the beneficial effects of extending rotation lengths to break disease cycles as shown by improved barley yields. The choice of cropping sequence, however, significantly influences subsequent grain yields. While barley yields were highest for the 2-year and 4-year rotations and lowest for the barley-soybean rotation, net returns were generally highest for the 4-year and continuous barley systems. Soil properties such as organic matter, pH, and Al concentration did not change significantly with the use of extended rotations, however, the potential for soil erosion was reduced by use of zero-tillage management
Preservation of a highly perishable food, watermelon juice, at and above room temperature under mild pressure (hyperbaric storage) as an alternative to refrigeration
The feasibility of food preservation under pressure (hyperbaric storage) at and above room temperatures,
as an alternative to refrigeration was evaluated. Preservation of a highly perishable food, watermelon
juice, was studied at pressures of 25e150 MPa and temperatures ranging 20e37 C, being compared to
refrigeration and storage at atmospheric pressure at the same temperatures.
Hyperbaric storage at 75 MPa (20e37 C) revealed an inhibitory effect on microbial growth, with at
least an equal performance compared to refrigeration. An additional inactivation effect was verified for
storage at 100 and 150 MPa, with reduction of the initial microbial counts to 1.00 Log CFU/mL for
enterobacteriaceae and yeasts and moulds, and from 4.43 ± 0.04 to 3.31 ± 0.04 and 2.99 ± 0.07 Log CFU/
mL, respectively, for total aerobic mesophiles (25 C).
In general, pH, titratable acidity and total soluble solids did not show a clear variation trend with
pressure and no considerable differences among storage conditions were verified. Cloudiness decreased
for samples stored under pressure and browning degree was in general lower in samples stored under
pressure compared to refrigeration.
This work demonstrates the potentiality of hyperbaric storage as a new preservation methodology, at
variable (uncontrolled) room temperature without energetic costs during storage, as an alternative to
refrigeration
High pressure and thermal pasteurization effects on sweet cherry juice microbiological stability and physicochemical properties
This study evaluated high pressure processing (P1 – 400 MPa/5 min; P2 – 550 MPa/2 min) and thermal
pasteurization (TP – 70°C/30 s) effects on sweet cherry juice’s microbiological and physicochemical
parameters, during four weeks of refrigerated storage. All treatments reduced the microbiological load
to undetectable levels not affecting total soluble solids and titratable acidity. The pH increased with all
treatments, however, it decreased during storage. Phenols were differently affected: TP increased them
by 6%, P1 had no effect while P2 decreased them by 11%. During storage, phenols in control and TP
samples decreased by 26% and 20%, P1 samples decreased them by 11% whereas P2 showed no variation.
TP had no effect on anthocyanins, while pressure treatments increased them by 8%. Anthocyanins
decreased during storage, particularly in the control and P1 (decreasing 41%). All treatments had no effect
on antioxidant activity until the 14th day, thereafter high pressure processing samples showed the highest
antioxidant activity
Preservation under pressure (hyperbaric storage) at 25ºC, 30ºC and 37ºC of a highly perishable dairy food and comparison with refrigeration
Hyperbaric storage (HS) under mild pressure of requeijão, a traditional Portuguese whey cheese, as a case study of a highly perishable dairy food, was evaluated as a possible energy costless alternative to refrigeration. Whey cheese was stored for 4 and 8 hours, at different pressure levels (0.1, 100 and 150 MPa) and temperatures (25°C, 30°C and 37°C), and the results were compared with refrigeration (4°C). Microbial
analyses showed that storage for 4 hours at 100 MPa was able to maintain microbial counts similar to refrigeration and initial load, ≈3 Log10 CFU/g, at all tested temperatures. By increasing the pressure to 150 MPa and the storage time to 8 hours, microbial loads were reduced to undetectable counts, with the exception for total aerobic mesophiles that were reduced to about ≈1 Log unit. HS in general maintained pH, water activity and lipid oxidation values, at levels similar to that in refrigeration
Food preservation under pressure (hyperbaric storage) as a possible improvement/alternative to refrigeration
Food preservation is highly dependent on refrigeration, which is limited by its high energy costs.
Among alternatives being developed, this review focused on hyperbaric storage (food preservation under pressure).
This new preservation methodology has as main objective microbial growth inhibition similarly to freezing and
refrigeration, showing a great potential to lower energy costs since refrigerated/room temperatures (RT) can be
used. This, even at variable (uncontrolled) RT (up to 37 C), has been shown to preserve foods and thus
achieving significant energy savings. Covering the earliest up to the more recent studies, this review aimed to gather information about the state of art of hyperbaric storage at refrigerated and RTs, with the primary objective of showing it potential and possible future applications of this new preservation method based on microbial growth inhibition under pressure, using pressure as the main variable to slow down microbial growth
Relationship between the occurrence of filamentous bacteria on Bathymodiolus azoricus shell and the physiological and toxicological status of the vent mussel
En libre-accès sur Archimer : http://archimer.ifremer.fr/doc/2009/publication-6821.pdfInternational audienceThe edifice walls of the Eiffel Tower hydrothermal vent site (Mid-Atlantic Ridge, Lucky Strike vent field) are populated with dense communities of dual symbioses harboring vent mussel Bathymodiolus azoricus, some of which are covered by white filamentous mats belonging to sulfur-oxidizing bacteria. Mussels were collected in both the presence and absence of the filamentous bacteria. A sample of the filamentous bacteria was collected and water measurements of temperature, CH4 and H2S were recorded at the collection area. The whole soft tissues were analyzed for total lipid, carbohydrate and total protein. Metallothioneins and metals (Cu, Fe and Zn) levels were determined in the major organs. The results showed no significant physiological and toxicological evidence that emphasizes the influence of associated sulfur-oxidizing filamentous bacteria on B. azoricus mussel shells. However, B. azoricus mussel seems to be well adapted to the assorted physico-chemical characteristics from the surrounding environment since it is able to manage the constant fluctuation of physico-chemical compounds
Analysis of phenolic, polysaccharidic and lipidic fractions of mushrooms from northeast Portugal
Mushrooms consumption continues to increase due to their functional benefits and presence of
bioactive compounds. Herein, phenolic, polysaccharidic and lipidic fractions of wild mushrooms
from Northeast Portugal (Coprinopsis atramentaria, Lactarius bertillonii, Lactarius vellereus,
Rhodotus palmatus and Xerocomus chrysenteron) were analysed. Protocatechuic, phydroxybenzoic,
p-coumaric and cinnamic acids were found in the phenolic fraction; ramnose,
xylose, fucose, arabinose, fructose, glucose, manose, mannitol, sucrose, maltose and trehalose were
quantified in polysaccharidic fraction; linoleic and stearic (only in Lactarius sp.) acids, and β- and
γ-tocopherols were the main compounds in the lipidic fraction
Bioactivity and chemical characterization of phenolic and anthocyanin extracts of Arbutus unedo L. wild fruits
Phenolic metabolites are common constituents of fruits and vegetables, and the interest of plant
phenolic extracts derives from the evidence of their potent antioxidant activity and their wide range
of pharmacologic properties including anticancer, antimicrobial and platelet aggregation inhibition
activities. The fruits of Arbutus unedo L. are eaten raw or made in liqueurs (1 ]. In traditional folk
medicine, they are reported as having antiseptic, diuretic and laxative effects, being also used to
treat arterial hypertension (2) .Moreover, the bark or roots decoctions are used as anti-inflammatory,
laxative, carminative, digestive, odontalgic and cardiotonic. In this work, two
different enriched phenolic extracts were prepared from A. unedo frutis, in order to evaluate and
compare their bioactivity: a phenolic extract without anthocyanins (PE; with phenolic acids,
flavones/ols, flavan-3-ols and galloyl derivatives) and a separate anthocyanins extract (AE). A.
unedo PE presented the highest antioxidant activity in all the in vitro assays (free radicals
scavenging activity, reducing power and lipid peroxidation inhibition), which could be related to the
presence of galloyl derivatives. The antiproliferation activity was tested in different human tumour
cell lines (breast, lung, colon, cervical and hepatocellular carcinomas), and the hepatotoxicity was
evaluated using a porcine liver primary cell culture (PLP2). A. unedo PE also gave the highest
antiproliferation inhibition presenting a Gl50 value=38 119/ml for NCI-H460- non-small lung
carcinoma cell line, without toxicity for PLP2 (GI 50>400 119/m l). Overall, the results showed that A.
unedo fruits may have great potential for food industries as a source of colors and flavors, as well
as bioactive molecules such as phenolic compounds for dietary supplements or functional foods
A importância dos ácidos fenólicos na atividade anti-inflamatória de cogumelos comestíveis
Os cogumelos comestíveis são uma fonte rica de moléculas bioativas que lhes conferem importantes atividades biológicas. Moléculas
como os Polissacáridos, terpenóides e os compostos fenólicos têm sido descritos como os componentes mais importantes no que respeita
á atividade anti-inflamatória dos cogumelos (1). No presente trabalho, os extratos etanólicos de cogumelos comestíveis foram obtidos
por maceração e caracterizados quimicamente em termos de ácidos fenólicos por técnicas de HPLC-DAD. Além disso, derivados
metilados e glucuronados dos ácidos fenólicos identificados foram também sintetizados com o objetivo de mimetizar reações de
metabolização no organismo e estudar a capacidade destas moléculas de manter a bioatividade exibida inicialmente. Os extratos obtidos,
os ácidos fenólicos e compostos sintetizados foram avaliados pela sua atividade anti-inflamatória. De entre as amostras analisadas, B. impolitus revelou o mais elevado conteúdo em ácidos fenólicos (675 ± 23 μg/g), seguido de C. cibarius
> A. caesaria > L. deliciosus > B. aereus > M. esculenta > B. edulis; devido à contribuição do ácido cinâmico que foi encontrada em maior
quantidade nesta amostra (505 ± 12 μg/g). Mais ainda, B. impolitus apresentou também maior inibição da produção de NO (EC50=166 ± 10
μg/mL) seguido das amostras A. caesaria > C. cibarius > L. deliciosus > M. esculenta > B. aereus > B. edulis. No que respeita aos compostos
individuais, o ácido cinâmico (CA) revelou a atividade mais forte (EC50 = 182 ± 16 μM), seguido pelos ácidos p-hidroxibenzóico (HA) (239 ±
29 μM) e p-Cumárico (CoA) (442± 33 μM), o que realça a importância destas moléculas para a atividade anti-inflamatória dos cogumelos.
Comparando a atividade exibida pelos ácidos fenólicos com os respetivos derivados, é possível verificar a seguinte ordem de atividades:
ácido p-hidroxibenzóico: HA > HA-M3 > HA-M2 > HA-M1 > HA-G; ácido p-cumárico : CoA-M1 > CoA-G > CoA-M2 > CoA-M3 > CoA e ácido
cinâmico: CA-G > CA > CA-M1. Perante os resultados obtidos é de realçar a importância dos ácidos fenólicos na contribuição para a
bioatividade exibida pelos cogumelos em estudo. Mais ainda, foi possível concluir que as alterações das moléculas pelas reações de
conjugação no organismo têm influência na bioativade das moléculas iniciais, sendo que muitas vezes esta atividade é aumentada
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