Identification of yield coefficients in a baker’s yeast model: an optimal experimental design approach

The main objective of this work is to elaborate methodologies that allow the identification of yield coefficients through complete measurements of the state. Experimental design strategies are proposed in order to optimize the richness of data coming out from the experiments, quantified by indexes related to the Fisher information matrix. The objectives of the experimental planning have been addressed in terms of the programming of input trajectories. The experimental planning is envisaged for baker’s yeast aiming at the computation of the substrate feed trajectories

Levantamento da situação de descarga de águas residuais industriais das empresas sediadas nos Parques Industriais de Adaúfe e Celeirós

O levantamento da situação de descarga de águas residuais industriais das empresas sediadas nos Parques Industriais de Adaúfe e Celeirós foi efectuado de Abril a Junho de 2000. A AGERE- E.M. como empresa responsável pelos sistemas de drenagem e tratamento de esgotos, demonstrou todo o interesse neste trabalho, uma vez que lhe permitiu conhecer pormenorizadamente as actividades industriais predominantes e consequentemente o tipo de efluentes produzidos. Este levantamento foi conseguido através de um trabalho de campo que englobou a visita às empresas com conhecimento directo dos seus processos produtivos. Desta forma, efectuou-se uma recolha rigorosa e exaustiva da situação quanto ao: ramo de actividade industrial, identificação e características da empresa, processo produtivo, abastecimento de água, caracterização de efluentes e ainda recolha de outros elementos que permitiram de uma forma actual, possuir um conjunto de informações importantes para o conhecimento da realidade das indústrias sediadas nestes parques

(Oligo)thienyl-imidazo-benzocrown ether derivatives : synthesis, photophysical studies and evaluation of their chemosensory properties

A series of novel (oligo)thienyl-imidazobenzocrown ethers were synthesised through a simple method and evaluated as fluorimetric chemosensors for transition metal cations. Interaction with Ni2+, Pd2+, and Hg2+ in ACN/DMSO solution (99:1) was studied by absorption and emission spectroscopy. Chemoselectivity studies in the presence of Na+ were also carried out and a fluorescence enhancement upon chelation (CHEF) effect was observed following Hg2+ complexation. Considering that most systems using fluorescence spectroscopy for detecting Hg2+ are based on the complexation enhancement of the fluorescence quenching (CHEQ) effect, the present work represents one of the few examples for sensing of Hg2+ based on a CHEF effect.Fundação para a Ciência e a Tecnologia (FCT) - PTDC/QUI/66250/2006, SFRH/BD/36396/2007, SRFH/BPD/72557/201

Overcoming inertia : drivers of the outsourcing process

Almost all managers have directly or indirectly been involved in the practice of outsourcing in recent years. But as they know, outsourcing is not straightforward. Outsourcing inertia, when companies are slow to adapt to changing circumstances that accommodate higher outsourcing levels, may undermine a firm’s performance. This article investigates the presence of outsourcing inertia and the factors that help managers overcome it. Using statistical evidence, we show that positive performance effects related to outsourcing can accumulate when circumstances change. This is then followed by rapid increases in outsourcing levels (i.e. outsourcing processes). We investigate what gives rise to these outsourcing processes through follow-up interviews with sourcing executives, which suggest five drivers behind outsourcing processes: managerial initiative (using outside experience); hierarchy (foreign headquarters); imitation (of competitors and of similar firms); outsider advice (from external institutions); knowledge sources (using external information). These five drivers all offer scope for managerial action. We tie them to academic literatures and suggest ways of investigating their presence and impact on the outsourcing process. Overall, we conclude that while economizing factors play a key role in explaining how much firms outsource, it is socializing factors that tend to drive outsourcing processes

Analysis of the profile of volatile organic compounds in Chlorella vulgaris

It is known that the incorporation of microalgae into foodstuffs enables to modify the overall flavor leading to desirable or undesirable organoleptic properties. Nevertheless, few were the studies conducted focusing on the analysis of the profile of volatile organic compounds (VOCs) produced by microalgae, which are the main compounds responsible for the aroma perception. The aim of this study was to analyze the VOCs profile of Chlorella vulgaris powder by gas chromatography coupled with mass spectrometry (GC-MS). Different techniques were used for the extraction of the VOCs, prior to the chromatographic analysis: 1) solid-phase microextraction (SPME), and 2) ultrasound-assisted liquid extraction (UALE) using five different solvents. For the SPME analysis, 0.5 g of C. vulgaris was exposed to a divinylbenzene/carboxen/polydimethylsiloxane (DVB/CAR/PDMS) fiber and was desorbed for 5 min into GC-MS. For the UALE, 2 g of sample was placed in five different solvents for extraction (chloroform, dichloromethane, hexane, ethyl acetate and acetone). For both SPME and UALE the GC-MS analysis was performed on Stabilwax (SW) and RXI-5 columns. The results showed very different profiles of VOCs between columns and techniques of extractions. In the analysis with the SW column no compounds were detected in acetone, hexane and ethyl acetate and only a few were present with the chloroform (39 VOCs) and dichloromethane (15 VOCs) extraction when compared to SPME (75 VOCs). In the RXI-5 analysis, a reduced number of compounds was identified when comparing with SW in SPME (39 and 75 VOCs, respectively), and in UALE, ethyl acetate was the only solvent with any retention of VOCs that could be detected with this column, having chloroform, dichloromethane, acetone and hexane, 10, 10, 5, and 8 VOCs respectively. In SPME, the main chemical classes of identified VOCs were, alcohols and hydrocarbons. In UALLE, the VOCs profile was more balanced with alcohols, aldehydes, carboxy group, ketones and hydrocarbons. Only with hexane it was possible to find aromatic groups. Compounds such as hexanal, tetradecane, and 3-methylbutanal were found in SPME as reported in literature, although 3-methylbutanal was only present for SW. In conclusion, SPME run in a SW column showed more VOCs retention and seems to be more appropriate to enable aroma prediction in C. vulgaris-based foodstuff.Portuguese Foundation for Science and Technology (FCT) - 2021.05734.BDinfo:eu-repo/semantics/publishedVersio

Screening of Phaeodactylum tricornutum extracts regarding their bioactive and functional properties

The expanding interest in addressing a more sustainable and eco-friendlier product development regarding the problem of ecological preservation results in a growing community search for bioactive natural-based formulations. Microalgae extracts potential for their interesting bioactive properties has been widely recognized, with antioxidant activity accounting for a major application in cosmetics, pharmaceutics and nutrition fields, due to its health-promoting effects. Moreover, microalgae generally contain large amounts of structural biopolymers, which might possibly display interesting rheological properties. This work was designed to enhance microalgae potential biotechnology exploration by attaining at least two different main fractions, namely with bioactive and texturizing functions. Phaeodactylum tricornutum was used under a biorefinery concept, by performing extractions with several solvent systems with a wide polarity spectrum. Previous work enhanced this microalgae species potential as an antioxidant agent, regardless of the antioxidant quantification method used, when compared to Nannochloropsis oceanica and Chlorella vulgaris extracts. P. tricornutum powdered biomass was extracted (4% dry weight) using water or hydroethanolic mixtures (25-96%) under same conditions of extraction, namely, over one hour at three different temperatures: 40ºC, 60ºC and 80ºC. All extracts were screened for their bioactive potential by three different antioxidant activity measurement assays: FRAP, ABTS and DPPH, as well as chemical characterized regarding their phenolic and pigment content. Lipidic fraction was evaluated for ethanol 25%, 50% and 96% extracts. Rheological properties and emulsifying capacity and stability were determined for water and ethanol 25% extracts, while protein and carbohydrate content were also assessed. Overall, findings from this study suggest that P. tricornutum extracts have a great potential for biotechnology purposes: aqueous extracts were particularly interesting for their functional properties while bioactive properties were more relevant for the ethanolic extracts. These may due to a higher protein and carbohydrate fraction present in more aqueous extracts. On the other hand, extracts with higher concentration of ethanol evidenced a greater amount of pigments, phenolics and lipids. In this manner, further studies should be fulfilled in order to explore their application in natural-based product formulation.This work was supported by the Portuguese Foundation for Science and Technology (FCT), under the scope of the strategic funding of UID/BIO/04469/2020 unit. This study has also received funding from the European Fund for Regional Development (FEDER), COMPETE 2020 – Competitiveness and Internationalization Operational Program (Portugal 2020) and the European Regional Development Fund (Algarve 2020 and Lisboa 2020), under the scope of the project AlgaValor (grant agreement nº POCI-01-0247-FEDER-035234; LISBOA-01-0247-FEDER-035234; ALG-01-0247-FEDER-035234).info:eu-repo/semantics/publishedVersio

Screening of Phaeodactylum tricornutum extracts regarding theirbioactive and functional properties

The expanding interest in addressing a more sustainable and eco-friendlier product development regarding the problem of ecological preservation results in a growing community search for bioactive natural-based formulations. Microalgae extracts potential for their interesting bioactive properties has been widely recognized, with antioxidant activity accounting for a major application in cosmetics, pharmaceutics and nutrition fields, due to its health-promoting effects. Moreover, microalgae generally contain large amounts of structural biopolymers, which might possibly display interesting rheological properties. This work was designed to enhance microalgae potential biotechnology exploration by attaining at least two different main fractions, namely with bioactive and texturizing functions. Phaeodactylum tricornutum was used under a biorefinery concept, by performing extractions with several solvent systems with a wide polarity spectrum. Previous work enhanced this microalgae species potential as an antioxidant agent, regardless of the antioxidant quantification method used, when compared to Nannochloropsis oceanica and Chlorella vulgaris extracts. P. tricornutum powdered biomass was extracted (4% dry weight) using water or hydroethanolic mixtures (25-96%) under same conditions of extraction, namely, over one hour at three different temperatures: 40ºC, 60ºC and 80ºC. All extracts were screened for their bioactive potential by three different antioxidant activity measurement assays: FRAP, ABTS and DPPH, as well as chemical characterized regarding their phenolic and pigment content. Lipidic fraction was evaluated for ethanol 25%, 50% and 96% extracts. Rheological properties and emulsifying capacity and stability were determined for water and ethanol 25% extracts, while protein and carbohydrate content were also assessed. Overall, findings from this study suggest that P. tricornutum extracts have a great potential for biotechnology purposes: aqueous extracts were particularly interesting for their functional properties while bioactive properties were more relevant for the ethanolic extracts. These may due to a higher protein and carbohydrate fraction present in more aqueous extracts. On the other hand, extracts with higher concentration of ethanol evidenced a greater amount of pigments, phenolics and lipids. In this manner, further studies should be fulfilled in order to explore their application in natural-based product formulation.This work was supported by the Portuguese Foundation for Science and Technology (FCT), under the scope of the strategic funding of UID/BIO/04469/2020 unit. This study has also received funding from the European Fund for Regional Development (FEDER), COMPETE 2020 – Competitiveness and Internationalization Operational Program (Portugal 2020) and the European Regional Development Fund (Algarve 2020 and Lisboa 2020), under the scope of the project AlgaValor (grant agreement nº POCI-01-0247-FEDER-035234; LISBOA-01-0247-FEDER-035234; ALG-01-0247-FEDER-035234).info:eu-repo/semantics/publishedVersio

Osborne fractionation: an approach for red macroalgae proteinassessment

Although animal sources enhance consumers' nutritional satisfaction, their cost, consumers dietary restrictions, as well as an increasing interest in vegetarianism, organic food and locally grown foods emphasizes the importance of finding new sustainable alternatives of protein sources in order to satisfy anticipated increased global needs without magnifying the negative impact. Porphyra dioica, Gracilaria verrucosa and Chondrus crispus are examples of red algae species that are used as a source of valuable compounds that can satisfy the demand for different foods and help to decrease the impact on animals use as the main food nutrients supplier. Since there are a wide range of different proteins in macroalgae, it is important to study and assess which kind of proteins are present in different species, which will help to predict if they can be used to replace some conventional animal proteins. The main objective of this work was the application of Osborne method for protein recovery from red algae species using different solvents (e.g., H2O, NaCl, EtOH and NaOH). The produced fractions were characterized in terms of extraction yields, protein content (Lowry method) and molecular weight by gel electrophoresis (SDS-PAGE). Results showed that the maximum protein content was obtained for Porphyra dioica and the minimum value for Chondrus crispus (i.e., 29.12 and 7.13 %, respectively). Regarding Osborne fractionation, all species showed higher protein content in water and NaOH resulting proteins fractions, being the best results associated with Gracilaria verrucosa, with a total protein extraction yield (gprotein/gbiomass) of 12.39 %. Comparing to the initial protein content of Gracilaria verrucosa (17.45 ± 0.05 %dw) it is possible extract 70.99 % of total protein where 35.83 % and 18.05 % corresponds to water and NaOH fractions, respectively. From the SDS-PAGE gels it is clearly visible that different species showed proteins with different molecular weights. Thus, it can be concluded that the Osborne method is a promising approach to characterize algal protein and can help choosing the best conditions for higher protein recovery from red macroalgae. The extracted proteins may be applied into different food prototypes in order to substitute conventional animal protein sources.Portuguese Foundation for Science and Technology (FCT) - UIDB/04469/2020 unit and SFRH/BD/07527/2020; BioEcoNorte project (NORTE-01-0145-FEDER-000070); NORTE 2020 (Programa Operacional Regional do Norte 2014/2020); Portugal 2020; ESIF- European structural and investment funds.info:eu-repo/semantics/publishedVersio

Active aroma compounds assessment of processed and non-processed micro- and macroalgae by solid-phase microextraction and gas chromatography/mass spectrometry targeting seafood analogs

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/ fsufs.2022.1011020/full#supplementary-materialThe odor of four algae was investigated and compared to evaluate the potential of these algae to mimic shrimp aroma. Solid-phase microextraction followed by gas chromatography analysis coupled with sensory analysis was used for performance assessment. The volatile organic compounds were determined in non-processed, raw samples (r), and processed cooked (c) and cooking water (w) samples for two microalgae [Nannochoropsis oceanica (NO) and Tetraselmis chuii (TC)], two macroalgae [Ulva rígida (UR) and Saccharina latíssima (SL)], and shrimp Vannamei cong (SH). The results showed significant differences in the composition of volatile compounds between macroalgae and microalgae. The key odorants in macroalgae were octanal, 2-octenal, nonanal, and β-ionone, and in microalgae were 1,5-octadien-3-ol, hexanal, 2,4-decadienal, 2-octenal, octanal, nonanal, 3,5-octadien-2-one, and terpenes. The PCA analysis of GC-MS data showed odor similarities between the studied samples, which were divided into five main groups: (1) TC(c) and TC(w); (2) TC(r) and NO(c); (3) NO(r), NO(w), and SL(w); (4) SL(c), UR(r), UR(c), and UR(w); and (5) SL(r). The data from the sensory analysis show bigger similarities between the macroalgae and the shrimp odor. Overall, the data provided indicate that the cooking water and cooked samples are very similar in key components of odorants. These features allow the possibility to use algae and their processed resulting products as a shrimp flavor replacement in non-animal-based food formulations, thus decreasing the pressure on seafood crops and aquaculture-associated issues leading to more sustainable livestock. Furthermore, circularity and waste reduction may be further enabled by the use of otherwise wasted cooking water as an odorant agent.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and by LABBELS— Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020. This study was also funded by the ESIF—European Structural and Investment Funds under the scope of the projects ALGAVALOR—Microalgae integrated production and valorization of its various applications (ref. POCI-01-0247-FEDER-035234; LISBOA-01-0247-FEDER-035234; ALG-01-0247-FEDER-035234; through Portugal 2020), and BioEcoNorte project (ref. NORTE-01-0145-FEDER-000070, through Portugal 2020 and Norte2020). CM is recipient of a Ph.D. scholarship supported by FCT (Ref. 2021.05734.BD).info:eu-repo/semantics/publishedVersio