Effects of spray-drying and storage on astaxanthin content of Haematococcus pluvialis biomass

The main objective of this study was to evaluate the stability of astaxanthin after drying and storage at different conditions during a 9-week period. Recovery of astaxanthin was evaluated by extracting pigments from the dried powders and analysing extracts by HPLC. The powders obtained were stored under different conditions of temperature and oxygen level and the effects on the degradation of astaxanthin were examined. Under the experimental conditions conducted in this study, the drying temperature that yielded the highest content of astaxanthin was 220°C, as the inlet, and 120°C, as the outlet temperature of the drying chamber. The best results were obtained for biomass dried at 180/110°C and stored at −21°C under nitrogen, with astaxanthin degradation lower than 10% after 9 weeks of storage. A reasonable preservation of astaxanthin can be achieved by conditions 180/80°C, −21°C nitrogen, 180/110°C, 21°C nitrogen, and 220/80°C, 21°C vacuum: the ratio of astaxanthin degradation is equal or inferior to 40%. In order to prevent astaxanthin degradation of Haematococcus pluvialis biomass, it is recommended the storage of the spray dried carotenized cells (180/110ºC) under nitrogen and −21°C.info:eu-repo/semantics/publishedVersio

Biodegradation of p-nitrophenol by microalgae

A study was made on the use of a mixed microalgal consortium to degrade p-nitrophenol. The consortium was obtained from a microbial community in a waste container fed with the remains and by-products of medium culture containing substituted aromatic pollutants (nitrophenols, chlorophenols, fluorobenzene). After selective enrichment with p-nitrophenol (p-NP), followed by an antibiotic treatment, an axenic microalgal consortium was recovered, which was able to degrade p-nitrophenol. At a concentration of 50 mg L−1, total degradation occurred within 5 days. Two species, Chlorella vulgaris var. vulgaris f. minuscula and Coenochloris pyrenoidosa, were isolated from the microalgal consortium. The species were able to accomplish p-NP biodegradation when cultured separately, although Coenochloris pyrenoidosa was more efficient, achieving the same degradation rate as the original axenic microalgal consortium. When Coenochloris pyrenoidosa was associated with Chlorella vulgaris in a 3:1 ratio, complete removal of the nitro-aromatic compound occurred within three days. This is apparently the first report on the degradation of a nitro aromatic compound by microalgae

Learning based on interdisciplinary projects with students from several engineering courses: case study on energy sustainability

The study of environmental and energy issues are as important as the specific disciplines of engineering courses. Within this context, the Environmental Sciences course provided the students an analysis of the relationship between the specific disciplines of their courses with relevant environmental issues, using the Project-Based Learning Methodology. Students were sorted into teams of ten from different Engineering courses and encouraged to create a project with feasible solutions for economy of energy and use of more sustainable energy sources. As a result, three projects were proposed: 1. Development of an application where the consumers can analyze their electricity consumption and the best way to save it, using mobile platforms like Android®, IOS® and Windows Phone®. 2. "Recharge your ideas": project for the installation of an individual photovoltaic system, which is an individual and non-interconnected electrical energy generating system, in order to provide clean and sustainable energy in a safe and satisfactory way at the University campus. 3. "Low cost solar heater": developed to serve lowincome rural communities. A prototype was made to estimate all necessary costs to make it and what would be the return in economy for the residences. With the development of these projects, it is perceived that interdisciplinarity is fundamental to the understanding of the themes developed, requiring the effort of students and teachers from the most diverse areas of engineering. The solution to most of the current problems in different areas of knowledge requires a more effective dialogue between disciplines and between professionals towards more adequate and self-sustainable solutions. To the students in particular, these activities promoted a practical experience and theoretical approach of different processes of Science and Technology and the opportunity to act in the solution of problems based on the knowledge acquired in the course in the resolution of real environmental and energy problems.info:eu-repo/semantics/publishedVersio

Peer and team assessment: Strategies and applications in engineering courses

Teamwork is one of the competencies that more often are referred has required to professional practice in Engineering. Working in teams in the learning process has been referred to be an effective way to promote the development of technical competencies while promoting the development of teamwork competencies. The students identify teamwork as motivating for their self-learning. In a teamwork environment student can deal with self-knowledge, critical analysis, knowledge of the others, individual and group performances, feedback, resilience, synergy, decision making, commitment, participation, self-esteem, leadership, and entrepreneurship. All these characteristics come from the understanding that a team is formed by individuals with different experiences, origins and individual profiles. But what are the criteria for peer or teamwork assessment? Which methods give fair rewards for different contributions to the team and its peers? There are several peer assessments studies where many experiences are described, but there are not many studies that compare the strategies of peer assessments between them. For example, when the criteria have different weights or when the scores given by the peers are anonymous or when the scores are decided by the group, and so on. The objective of this work is to describe several strategies of peer and team assessment, considering the categorization and organization carried out in order to assumptions and/or purposes of each strategy. Thus, a contribution will be made for increasing peer and teamwork assessment in Engineering courses.FCT - Fundação para a Ciência e a Tecnologia (UIDCEC003192019

Team-based learning in an engineering course: An experience in Brazil

Team-Based Learning (TBL) is an active learning strategy, used for the first time in medical education, and its use in Engineering Education is still not well established as in health science education. This work is about an experience of use of TBL in two consecutive years (2017 and 2018) in undergraduate Engineering course in a public university in Brazil. The objectives are to describe an experience using TBL, its impact over students' performance and perception of students and teacher about this approach. Initially, students were divided into groups from 5 to 7 members. The subject of the courses was divided into 4 modules, each one of 4 weeks. Each module started with the Readiness Assurance Process - RAP (pre-class individual assignment, e.g. readings), followed by in-class Individual Readiness Assurance Test - iRAT, and Team Readiness Assurance Test - tRAT. Both tests were applied using Information Technology tools, in this case either Socrative, or Kahoot or Plickers. During classes, students performed activities designed to develop students' critical thinking skills, applying concepts learned from RAP. Moreover, the students had to perform processes of self and peer-assessment. Average scores from the RAP were statistically higher in tRAT (group tests) than in iRAT (individual tests) (t-test; p≤0.05), in both years, indicating that teamwork and peer-instruction were important to achieve a greater understanding of the subject. The perception of the students about TBL was collected by an end of class questionnaire. For 81% of the students, TBL methodology was better than teacher centred classes. Another point to be highlighted was the use of Information Technology tools for feedback, approved by 100% of the students who answered the inquiry. As suggestions for future improvements emerged the need to improve the didactic material for pre-class studies.This work has been supported by FCT – Fundação para a Ciência e Tecnologia within the Project Scope UIDCEC003192019

Selective activity of an anthocyanin-rich, purified blueberry extract upon pathogenic and probiotic bacteria

Blueberry extracts have been widely recognized as possessing antimicrobial activity against several potential pathogens. However, the contextualization of the interaction of these extracts with beneficial bacteria (i.e., probiotics), particularly when considering the food applications of these products, may be of importance, not only because their presence is important in the regular gut microbiota, but also because they are important constituents of regular and functional foodstuffs. Therefore, the present work first sought to demonstrate the inhibitory effect of a blueberry extract upon four potential food pathogens and, after identifying the active concentrations, evaluated their impact upon the growth and metabolic activity (organic acid production and sugar consumption) of five potential probiotic microorganisms. Results showed that the extract, at a concentration that inhibited L. monocytogenes, B. cereus, E. coli and S. enteritidis (1000 μg mL−1), had no inhibitory effect on the growth of the potential probiotic stains used. However, the results demonstrated, for the first time, that the extract had a significant impact on the metabolic activity of all probiotic strains, resulting in higher amounts of organic acid production (acetic, citric and lactic acids) and an earlier production of propionic acid.info:eu-repo/semantics/publishedVersio

Health promoting properties of blueberries: a review

With the strengthening of the link between diet and health, several foodstuffs have emerged as possessing potential health benefits such as phenolic rich fruits and vegetables. Blueberries, along with other berries, given their flavonoid and antioxidant content have long since been considered as a particularly interesting health promoting fruit. Therefore, the present work aimed to compile the existing evidences regarding the various potential benefits of blueberry and blueberry based products consumption, giving particular relevance to in vivo works and epidemiological studies whenever available. Overall, the results demonstrate that, while the evidences that support a beneficial role of blueberry and blueberry extracts consumption, further human based studies are still needed.info:eu-repo/semantics/publishedVersio

Antiadhesive and antibiofilm effect of malvidin-3-glucoside and malvidin-3-glucoside/neochlorogenic acid mixtures upon staphylococcus

Several reports on the biological activity of anthocyanin-rich extracts have been made. However, despite the association of said activity with their anthocyanin content, to the best of our knowledge, there are no previous works regarding the antimicrobial, antibiofilm and/or antiadhesive properties of anthocyanins alone. Therefore, the present work aimed to determine the effects of malvidin-3-glucoside, a major component of a previously reported extract, and the impact of its association with neochlorogenic acid (the only non-anthocyanin phenolic present in said extract), upon several Staphylococcus strains with varying resistance profiles. Results show that, while malvidin- 3-glucoside and malvidin-3-glucoside/neochlorogenic acid mixtures were unable to considerably inhibit bacterial growth after 24 h, they still possessed an interesting antibiofilm activity (with reductions of biofilm entrapped cells up to 2.5 log cycles, metabolic inhibition rates up to 81% and up to 51% of biomass inhibition). When considering the bacteria’s capacity to adhere to plain polystyrene surfaces, the inhibition ranges were considerably lower (21% maximum value). However, when considering polystyrene surfaces coated with plasmatic proteins this value was considerably higher (45% for adhesion in the presence of extract and 39% for adhesion after the surface was exposed to extract). Overall, the studied anthocyanins showed potential as future alternatives to traditional antimicrobials in adhesion and biofilm formation prevention.info:eu-repo/semantics/publishedVersio

Application of Scrum and PM Canvas in a Project-based Learning Approach

Project-based Learning (PBL) is a teaching and learning strategy that allows students to develop competences while working on projects. It is important to apply good management approaches in order to achieve all project and learning objectives. This paper presents an application of Scrum and Project Model Canvas (PM Canvas) to manage learning projects developed by teams of students in interaction with industrial companies. These projects are part of a Project-based Learning (PBL) approach developed in the fourth year of an integrated master program in Industrial Engineering and Management. A group of 5 students from the fifth year of the same degree gave support to the PBL teams regarding the utilization of these tools. The work was developed during one month with meetings every Fridays. These project management tools were applied to help the PBL teams to organize and share the tasks, as well as visualize and control the whole project. To evaluate the teams' performance and the way they are realizing the tasks, it was counted the number of tasks done in each weekday and the students were inquired in order to understand their perceptions of the use of these project management tools. The results revealed that the groups performed most of the tasks on Wednesday and the inquiry revealed that most of the PBL teams did not know and had never used project management tools. The inquiry also revealed that the project management tools were considered helpful for the control and organization of the project tasks, improving overall team performance.(undefined