Influence and comparison of thermal, ultrasonic and thermosonic treatments on physicochemical quality of orange juice

Orange juice is the most popular and consumed juice worldwide, associated with healthy eating habits. Thermal pasteurization treatments are used to preserve industrially produced juice. Unfortunately, this process removes many nutritious compounds. Therefore, other milder treatments are being studied to minimize the impact on the product's final quality. The main goal of this study was to evaluate the effect of thermosonication (TS) treatment on the quality of orange juice in comparison with heat (HT) and ultrasound (UT) treatments alone. Commercial pasteurized orange juice was treated by UT, HT or TS in a sonoreactor (20 kHz and 80% amplitude) at different temperatures 20, 30, 40, 50 and 60 °C for 90, 60, 60, 30 and 30 min, respectively. These treatment times were chosen to guarantee the Staphylococcus aureus inactivation. Physicochemical characteristics, such as pH, colour and Brix, and microbial cell counts, were evaluated before and after treatments. Principal components analysis (PCA) was carried out to detect simple patterns and differences.All treatments could reduce the S. aureus presence in at least 3 log cycles, except the HT at 20, 30 and 40 °C, where an increase in microbial counts was attained. The majority of quality characteristics were not significantly affected by the applied treatments, except a* value for US 20, 30 40 and 50°C, Brix for TS 60°C and pH for US 30 and 40 °C, TS 50°C and HT 20 and 50 °C. PCA revealed two components with eigenvalues greater than one, which explained 56.1% and 28.4% of the total variance, respectively. The first component was mostly influenced by a*, pH, L*, b* and Chroma, while the second by Hue and microbial inactivation. The second component allowed a clear distinction between types of treatment, while the first component allowed separation among the processing conditions of temperature/time.info:eu-repo/semantics/publishedVersio

Influence and comparison of thermal, ultrasonic and thermosonic treatments on physicochemical quality of orange juice

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Thermal and non-thermal orange juice pasteurization: the impact of ultrasound, thermosonication and heat treatment on S. aureus kinetic inactivation behaviour

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Predicting RNA secondary structure by the comparative approach: how to select the homologous sequences

<p>Abstract</p> <p>Background</p> <p>The secondary structure of an RNA must be known before the relationship between its structure and function can be determined. One way to predict the secondary structure of an RNA is to identify covarying residues that maintain the pairings (Watson-Crick, Wobble and non-canonical pairings). This "comparative approach" consists of identifying mutations from homologous sequence alignments. The sequences must covary enough for compensatory mutations to be revealed, but comparison is difficult if they are too different. Thus the choice of homologous sequences is critical. While many possible combinations of homologous sequences may be used for prediction, only a few will give good structure predictions. This can be due to poor quality alignment in stems or to the variability of certain sequences. This problem of sequence selection is currently unsolved.</p> <p>Results</p> <p>This paper describes an algorithm, <it>SSCA</it>, which measures the suitability of sequences for the comparative approach. It is based on evolutionary models with structure constraints, particularly those on sequence variations and stem alignment. We propose three models, based on different constraints on sequence alignments. We show the results of the <it>SSCA </it>algorithm for predicting the secondary structure of several RNAs. <it>SSCA </it>enabled us to choose sets of homologous sequences that gave better predictions than arbitrarily chosen sets of homologous sequences.</p> <p>Conclusion</p> <p><it>SSCA </it>is an algorithm for selecting combinations of RNA homologous sequences suitable for secondary structure predictions with the comparative approach.</p

Cosmic ray oriented performance studies for the JEM-EUSO first level trigger

JEM-EUSO is a space mission designed to investigate Ultra-High Energy Cosmic Rays and Neutrinos (E > 5 ⋅ 1019 eV) from the International Space Station (ISS). Looking down from above its wide angle telescope is able to observe their air showers and collect such data from a very wide area. Highly specific trigger algorithms are needed to drastically reduce the data load in the presence of both atmospheric and human activity related background light, yet retain the rare cosmic ray events recorded in the telescope. We report the performance in offline testing of the first level trigger algorithm on data from JEM-EUSO prototypes and laboratory measurements observing different light sources: data taken during a high altitude balloon flight over Canada, laser pulses observed from the ground traversing the real atmosphere, and model landscapes reproducing realistic aspect ratios and light conditions as would be seen from the ISS itself. The first level trigger logic successfully kept the trigger rate within the permissible bounds when challenged with artificially produced as well as naturally encountered night sky background fluctuations and while retaining events with general air-shower characteristics

Thermal and non-thermal orange juice pasteurization: the impact of ultrasound, thermosonication and heat treatment on S. aureus kinetic inactivation behaviour

S. aureus survival is a serious issue in the food field, which has pushed researchers to develop safe inactivation processes and, at the same time, not affect the food product’s nutritional value. All of this to meet the increasing consumer demand for safe and quality food. One of the non-thermal preservation methods that is used as a powerful disinfection technology is sonication. It is considered an efficient process since it satisfies the Food and Drug Administration requirements for a 5-log reduction of microbial cells in fruit juices. This study was designed to investigate Staphylococcus aureus’s kinetic inactivation behaviour when subjected to the combination of ultrasound and temperature (thermosonication) and heat treatment alone. Commercial pasteurized orange juice was inoculated with S. aureus ATCC 29213 to attain an inoculated juice with a final concentration of approximately 1012 CFU/mL. Cells were heat-treated and processed by ultrasound at 20 kHz at 20, 30, 40, 50, and 60 °C. For heat processing, the treatment times were 90, 60, 60, 60 and 35 min, while for ultrasound treatments, the times were 90, 60, 60, 35 and 30 min, respectively. S. aureus cell viability and sublethal injury were evaluated using two different platting media. SEM analyses were applied to identify the morphological appearance of S. aureus cells. Results showed that ultrasounds at 20, 30 and 40°C reduced the viable bacterium counts by approximately four log cycles at the end of treatment. On the opposing, sublethal temperatures without sonication did not affect S. aureus survival. Microscopic images exposed that cells undergo membrane damage during sonication. Thermosonication treatments at 50 and 60 °C were the most effective ones resulting in higher S. aureus inactivation rates and lesser treatment times than the heat treatments alone. This was proved by the higher presence of single-pore and flatted cells in thermosonicated samples at these temperature ranges. Hence, a synergistic effect was observed between thermal and ultrasound treatments, noted by increased cells susceptibility to cavitation effects. Therefore, thermosonication can be a promising processing technology for orange juice pasteurization.info:eu-repo/semantics/publishedVersio

Equipping tomorrow's doctors for the patients of today

As the proportion of older patients with frailty presenting to health services increases, so does the need for doctors to be adequately trained to meet their needs. The presentations seen in such patients, the evidence-based models of care and skillsets required to deliver them are different than for younger patient groups—so specific training is required. Several research programmes have used detailed and explicit methods to establish evidence-based expert-validated curricula outlining learning outcomes for undergraduates in geriatric medicine–there is now broad-consensus on what newly qualified doctors need to know. There are, despite this, shortcomings in the teaching of undergraduates about geriatric medicine. National and international surveys from the UK, EU, USA, Canada, Austria and the Netherlands have all shown shortcomings in the content and amount of undergraduate teaching. Mechanisms to improve this situation, aside from specifying curricula, include developing academic departments and professorships in geriatric medicine, providing grants to develop teaching in geriatric medicine and developing novel teaching interventions to make the best of existing resources. Under the last of these headings, innovations have been shown to improve outcomes by: using technology to ensure the most effective allocation of teaching time and resources; using inter-professional education as a means of improving attitudes towards care of older patients; focusing teaching specifically on attitudes towards older patients and those who work with them; and trying to engage patients in teaching. Research areas going forward include how to incentivise medical schools to deliver specified curricula, how to choose from an ever-expanding array of teaching technologies, how to implement interprofessional education in a sustainable way and how to design teaching interventions using a qualitative understanding of attitudes towards older patients and the teams that care for them

A representation of a Tuawhenua worldview guides environmental conservation

Indigenous peoples and local communities interact with approximately two-thirds of the world's land area through their worldviews and customary tenure regimes and offer significant knowledge contributions and lessons about sustainability. We worked with Tuawhenua Māori to document domains, concepts, and mechanisms within the worldview representation in a way that could guide environmental conservation in New Zealand. We then applied the framework to a cultural keystone species for Tuawhenua, the kererū ([New Zealand pigeon [(Hemiphaga novaeseelandiae]) to elucidate this human-environment relationship. Whakapapa (genealogy), whenua (land), and tangata (people) were interconnected domains that formed the conceptual basis of our framework. Within these domains, the concepts of mauri (life essence), mana (authority), and ihi (vitality) guided the expression of the community's relationship with the environment. Cultural expressions related to the kererū demonstrated the cultural significance of the bird to Tuawhenua that went well beyond the ecological and intrinsic value of the species. The Tuawhenua worldview representation also emphasized the human-nature relationship and the role that metaphor plays in expressing this relationship. Indigenous peoples and local community worldviews are important for establishing priorities, reconciling the human relationship with the environment, and facilitating the coproduction of knowledge in response to pressing local and global environmental conservation issues

Ultrasound and heat treatment effects on Staphylococcus aureus cell viability in orange juice

Ultrasounds are being considered an excellent alternative technology in juice preservation. Yet, when combined with heat treatment, the process seems to be further intensified. This work aimed to evaluate and compare the impact of ultrasounds and heat treatments, when applied alone or in combination, on Staphylococcus aureus survival in orange juice. Inoculated commercial pasteurized orange juice was treated at different times at 20, 30, 40, 50 and 60 °C. SEM analyses were applied to identify morphological changes in S. aureus cells appearance. The microbial inactivation data were fitted using two mathematical models, depending on the behaviour observed. Sonication at 20, 30, and 40 °C induced 4.02 ± 0.52, 3.80 ± 0.49 and 4.30 ± 0.74 log cycles reduction of S. aureus after treatments of 90, 60 and 60 min, respectively. The heat treatments at the same temperatures had no impact on S. aureus survival. When 50 and 60 °C were applied, more than 5-log reductions were attained for both thermosonication and heat treatments alone. A synergistic effect was observed between sonication and high temperatures. At 50 °C, the thermosonication reduced the treatment time from 60 to 35 min and the microbial load from 5.14 ± 0.08 to 10.76 ± 0.28 log cycles reduction, compared to heat treatment alone. Results from SEM images showed that cells undergo membrane damage during sonication exposure. This was observed by collapsed cells, cell disruption, and holes in the cell's membrane. Thermosonication proved to be a viable alternative to thermal pasteurization of orange juice since milder treatments can be safely applied, improving the final product quality.info:eu-repo/semantics/publishedVersio