207 research outputs found

    Bemerkung zum Hauptsatz der Galoisschen Theorie für Schiefkörper

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    Effect of freezing, fast-freezing by liquid nitrogen or refrigeration to preserve premium extra virgin olive oil during storage

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    During storage, premium extra virgin olive oils (PEVOO), which are oils of exceptional sensory quality, may lose the organoleptic characteristics that define them. This study assessed the effect of applying modified atmospheres and low temperatures (refrigeration and freezing) on the quality of 4 PEVOO for 24 months. Also, the effect of two freezing methods was studied (in the freezer at − 20 °C and in a bath of liquid nitrogen), along with the impact of freezing on the quality of the oils after thawing and storing at room temperature. Official quality parameters, organoleptic assessment, phenolic compounds, volatile compounds and oxidative stability index were measured periodically. While no significant effect of headspace composition was found, the oils stored at − 20 °C maintained their initial quality better than the oils stored at room temperature. Physicochemical quality parameters remained unchanged throughout the 24 months at − 20 °C. Polar phenolic and volatile compounds associated with green and fruity aromas were better preserved at − 20 °C, which translated into a minimum change in the sensory profile of the oils. While no significant difference was observed regarding oxidative parameters, freezing at − 20 °C maintained the initial volatile and sensory profile of the oils better than freezing with liquid nitrogen. Lastly, quality of thawed oils showed no significant differences compared to control oils during storage at room temperature. In conclusion, storage at − 20 °C maintains the quality of PEVOO, especially their sensory profile, and does not compromise their quality after thawing

    Subzero temperature storage to preserve the quality attributes of veiled virgin olive oil

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    This study evaluated the effect of using olive pomace acid oil (OPAO) instead of crude palm oil (PO) or refined olive pomace oil (ROPO) on lipid composition, lipid oxidation, and quality of chicken meat. Broiler chickens were fed diets with 6% of PO, ROPO, or OPAO, and deboned legs with skin were sampled. Fresh and refrigerated (commercial conditions; 7 days) chicken meat samples were assessed for fatty acid (FA) composition, tocopherol (T) and tocotrienol (T3) content, lipid oxidative stability, 2-thiobarbituric acid (TBA) values, volatile compounds, color, and sensory acceptance. Using ROPO and OPAO led to meat richer in monounsaturated FAs and OPAO to lower α-T levels compared to PO. Oxidative stability, TBA values, volatile compounds, and overall acceptance of meat were not affected by diet. Refrigeration increased TBA values and some volatile compounds’ concentrations, but it did not decrease redness or consumers’ overall acceptance. Therefore, the OPAO used was an adequate fat source for chicken diets at 6%, as it produced dark meat lower in saturated FAs than PO without affecting lipid oxidation or overall acceptance. According to this, upcycling OPAO as an energy source in chicken diets would be possible, which can contribute to the sustainability of the food chain. Keywords: edible oil refining by-product; upcycling; chicken feed; chicken diet; poultry meat quality; fat by-product; broiler meat; meat refrigeration; palm oil; olive pomace oi

    Resiliencia en sistemas dunares litorales altamente antropizados: la restauración del sistema dunar de la playa del Remolar (Viladecans, Barcelona)

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    Con el fin de recuperar y restaurar el sistema playa-duna del Remolar (700 m de longitud y más de 100 m de ancho, de dirección 070N), se propusieron en 2004 una serie de medidas de restauración blanda. Para valorar dichas medidas, transcurridos 10 años, se efectuó un estudio de la morfología, sedimentología y de la vegetación del ecosistema. Se realizó el levantamiento de perfiles topográficos y de GPR, un análisis granulométrico y un análisis de las comunidades vegetales encontradas a lo largo de los perfiles topográficos. Los datos obtenidos han sido comparados con datos de un estudio previo, realizado en el 2004. Los resultados muestran que la morfología dunar se ha recuperado, originándose una nueva duna primaria. El sistema presenta actualmente un proceso mayor de agradación que de progradación. La vegetación ha recuperado una composición global de sistema dunar, con una comunidad típica de duna embrionaria y otras de duna primaria, en bandas paralelas a la costa. A pesar de esta mejora, la componente de tipo oportunista y ruderal de la vegetación de duna primaria denota una fuerte herencia antrópica en el sistema

    A comparison of a structured home-based rehabilitation programme with conventional supervised pulmonary rehabilitation:A randomised non-inferiority trial

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    Background: Standardised home-based pulmonary rehabilitation (PR) programmes offer an alternative model to centre-based supervised PR for which uptake is currently poor. We determined if a structured home-based unsupervised PR programme was non-inferior to supervised centre-based PR for participants with COPD. Methods: A total of 287 participants with COPD who were referred to PR (187 male, mean (SD) age 68 (8.86) years, FEV1% predicted 48.34 (17.92)) were recruited. They were randomised to either centre-based PR or a structured unsupervised home-based PR programme including a hospital visit with a healthcare professional trained in motivational interviewing, a self-management manual and two telephone calls. Fifty-eight (20%) withdrew from the centre-based group and 51 (18%) from the home group. The primary outcome was dyspnoea domain in the chronic respiratory disease questionnaire (Chronic Respiratory Questionnaire Self-Report; CRQ-SR) at 7 weeks. Measures were taken blinded. We undertook a modified intention-to-treat (mITT) complete case analysis, comparing groups according to original random allocation and with complete data at follow-up. The non-inferiority margin was 0.5 units. Results: There was evidence of significant gains in CRQ-dyspnoea at 7 weeks in both home and centre-based groups. There was inconclusive evidence that home-based PR was non-inferior to PR in dyspnoea (mean group difference, mITT: −0.24, 95% CI −0.61 to 0.12, p=0.18), favouring the centre group at 7 weeks. Conclusions: The standardised home-based programme provides benefits in dyspnoea. Further evidence is needed to definitively determine if the health benefits of the standardised home-based programme are non-inferior or equivalent to supervised centre-based rehabilitation

    Trials

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    BACKGROUND: An international workshop on population health intervention research (PHIR) was organized to foster exchanges between experts from different disciplines and different fields. This paper aims to summarize the discussions around some of the issues addressed: (1) the place of theories in PHIR, (2) why theories can be useful, and (3) how to choose and use the most relevant of them in evaluating PHIR. METHODS: The workshop included formal presentations by participants and moderated discussions. An oral synthesis was produced by a rapporteur to validate, through an expert consensus, the key points of the discussion and the recommendations. All discussions were recorded and have been fully transcribed. RESULTS: The following recommendations were generated through a consensus in the workshop discussions: (i) The evaluation of interventions, like their development, could be improved through better use of theory. (ii) The referenced theory and framework must be clarified. (iii) An intervention theory should be developed by a partnership of researchers and practitioners. (iv) More use of social theory is recommended. (v) Frameworks and a common language are helpful in selecting and communicating a theory. (vi) Better reporting of interventions and theories is needed. CONCLUSION: Theory-driven interventions and evaluations are key in PHIR as they facilitate the understanding of mechanisms of change. There are many challenges in developing the most appropriate theories for interventions and evaluations. With the wealth of information now being generated, this subject is of increasing importance at many levels, including for public health policy. It is, therefore, timely to consider how to build on the experiences of many different disciplines to enable the development of better theories and facilitate evidence-based decisions

    Conservation of native wild ivory-white olives from the MEDES islands natural reserve to maintain virgin olive oil diversity

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    Food diversity, and in particular genetic diversity, is being lost at an alarming rate. Protection of natural areas is crucial to safeguard the world’s threatened species. The Medes Islands (MI), located in the northwest Mediterranean Sea, are a protected natural reserve. Wild olive trees also known as oleasters make up part of the vegetation of the Meda Gran island. Among them, in 2012, a wild albino ivory-white olive tree with fruit was identified. Fruits were collected from this tree and their seeds were first sown in a greenhouse and then planted in an orchard for purposes of ex situ preservation. Seven out of the 78 seedling trees obtained (12%) produced ivory-white fruits. In autumn 2018, fruits from these trees were sampled. Although the fruits had low oil content, virgin olive oil with unique sensory, physicochemical, and stability characteristics was produced. With respect to the polyphenols content, oleacein was the main compound identified (373.29 ± 72.02 mg/kg) and the oleocanthal was the second most abundant phenolic compound (204.84 ± 52.58 mg/kg). Regarding pigments, samples were characterized by an intense yellow color, with 12.5 ± 4.6 mg/kg of chlorophyll and 9.2 ± 3.3 mg/kg of carotenoids. Finally, oleic acid was the main fatty acid identified. This study explored the resources of the natural habitat of the MI as a means of enrichment of olive oil diversity and authenticity of this traditional Mediterranean foodinfo:eu-repo/semantics/publishedVersio

    High hydrostatic pressure enhances the formation of oleocanthal and oleacein in 'Arbequina' olive fruit

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    During olive oil production, the activity of endogenous enzymes plays a crucial role in determining the oil's phenolic composition. β-Glucosidase contributes to the formation of secoiridoids, while polyphenol oxidase (PPO) and peroxidase (POX) are involved in their oxidation. This study investigated whether high hydrostatic pressure (HHP), known to cause cell disruption and modify enzymatic activity and food texture, could reduce PPO and POX activity. HHP was applied to ‘Arbequina’ olives at different settings (300 and 600 MPa, 3 and 6 min) before olive oil extraction. The tested HHP conditions were not effective in reducing the activity of PPO and POX in olives, resulting in oils with a lower phenolic content. However, HHP increased the secoiridoid content of olives, particularly oleocanthal and oleacein (>50%). The pigments in oils produced from HHP-treated olives were higher compared to the control, whereas squalene and α-tocopherol levels and the fatty acid profile remained the same. © 2023 The Authors</p

    Optimizing the Malaxation Conditions to Produce an Arbequina EVOO with High Content of Bioactive Compounds

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    To meet the growing demand for high-quality extra-virgin olive oil (EVOO) with healthpromoting properties and pleasant sensory properties, studies are needed to establish optimal production parameters. Bioactive components of EVOO, including phenolic compounds, carotenoids, chlorophylls, tocopherols, and squalene, contribute to its organoleptic properties and beneficial health effects. The aim of this study was to develop an Arbequina EVOO with high phenol content, particularly oleocanthal and oleacein, on a laboratory scale by analyzing the effects of different temperatures (20, 25, and 30 â—¦C) and times (30 and 45 min) of malaxation. Higher temperatures decreased the levels of the phenolic compounds, secoiridoids, tocopherols, and squalene, but increased the pigments. EVOO with the highest quality was produced using malaxation parameters of 20 â—¦C and 30 min, although oleocanthal and oleacein were higher at 30 and 25 â—¦C, respectively. Overall, 20 â—¦C and 30 min were the processing conditions that most favored the physiological and chemical processes that contribute to higher levels of bioactive compounds in the oil and diminished their degradation and oxidation processes
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