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The digestion of S. nigra extracts influences the stability of its phenolic compounds, although they are able to exert their bioactivity. Non-digested and digested extracts have low toxicity and differentiated activity in normal and cancerous cells.

Fibers from passion fruit stalks were first recovered with a pulping and bleaching process. Two mechanical treatments were further applied to the fibers, homogenization (with and without ultrasound), and blender application. The effect of those treatments on fibers was evaluated. The chemical composition of the different stages of fibers undergoing treatment were measured according to TAPPI standards and were also analyzed by SEM, FTIR, and XRD. Trypsin was immobilized by adsorption and by covalent binding. The biocatalyst support-trypsin was evaluated in terms of immobilization yield, retention, and enzymatic activity. The experimental results demonstrated that the final cellulose concentration in the fibers was 44 % higher than that in the raw stalks. The cellulose nanofibers obtained by homogenization presented a size distribution between 20200 nm, and the application of ultrasound did not show a significant effect on size (between 50 to 300 nm). Trypsin immobilized using glycidol presented an immobilization yield of 67 % and presented higher retention and enzymatic activity (1.17±0.05 U/mg protein and 44.0±2.0 %, respectively). These results show that passion fruit stalks can be successfully used as a source of cellulose nanofibers and also can be used as carriers for the immobilization of trypsin., The authors acknowledge the financial support of Universidad Nacional de Colombia (Hermes code project 34573), COLCIENCIAS call 727-2015 National Doctorates. FONTAGRO (ATN/RF-16111-RG Productividad y Competitividad Frutícola Andina), and Erasmus+Programme Key Action 1. This work was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of the UID/BIO/04469/2020 unit and by the BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte., info:eu-repo/semantics/publishedVersion

Microalgae are a promising and sustainable ingredient for functional food development, due to their rich nutritional and health-promoting effects. Moreover, microalgae generally contain large amounts of structural biopolymers such as proteins and polysaccharides, which might display interesting technological features and rheological properties. This study aims at unravelling Phaeodactylum tricornutum extracts (PTE) potential role as structuring agents for food applications. Distilled water and a mixture of water/ethanol (75/25, v v1) were used as solvents. Extracts physicochemical properties were analysed regarding protein folding, molecular weight distribution, polymer interactions, and their main functional groups. PTE thermal properties, rheological behaviour, and emulsifying capacities were also evaluated. PTE showed different gelling mechanisms, with 40°C aqueous purified extracts reporting the strongest gel character. Moreover, 80°C ethanolic purified extracts showed the greatest emulsifying potential, with an initial emulsification index (EI) of around 90%. This EI decreased to 60% after 10 days, but remained constant for the following 15 days, showing an interesting emulsion stability. Overall, these findings suggest that PTE have a great potential for further application as thickening or emulsifier food ingredients. This diatom revealed to be a valuable source of structurally diverse, technologically active compounds., Portuguese Foundation for Science and Technology (FCT), under the scope of the strategic funding of UID/BIO/04469/2020 unit and OH2O (grant agreement nº POCI-01-0145-FEDER-029145). 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) and OH2O. Ricardo N. Pereira acknowledges FCT for its Assistant Research contract obtained under CEEC Individual 2017, info:eu-repo/semantics/publishedVersion

Tagatose is a rare sugar with increasing commercial interest as sweetener. Biotechnological production of d-tagatose by enzymatic isomerization of d-galactose provides an alternative to chemical processes. In the last years, l-arabinose isomerases (L-AIs) from different origins have been studied to increase the effectiveness of tagatose production. In this work, the L-AI from Bacillus subtilis, previously reported to have unique substrate specificity for l-arabinose, was expressed in Escherichia coli and studied for isomerization of d-galactose to d-tagatose. The recombinant enzyme demonstrated, for the first time, tagatose bioconversion capacity, reaching ~59% conversion. Furthermore, a sustainable tagatose production strategy was developed by using Gelidium sesquipedale red seaweed and its undervalued processing residues as source of galactose. L-AI successfully converted the galactose-rich hydrolysate, obtained from direct acid hydrolysis of seaweed, to tagatose (50.9% conversion). Additionally, the process combining autohydrolysis of G. sesquipedale and acid hydrolysis of the remaining residue allowed a full integral valorisation of polysaccharides: 13.33 g of agar, an important hydrocolloid, coupled with the production of 5.97 g of tagatose. These results confirmed that seaweed biomass and waste-derived are promising substrates for tagatose production by L-AI, contributing to the advancement of circular economy and to the actual needs of food industry., This study was supported by the Portuguese Foundation for Science and Technology (FCT, Portugal) under the scope of the strategic funding of UIDB/04469/2020, the PhD grant (SFRH/BD/132717/2017 to SLB), and Biomass and Bioenergy Research Infrastructure (BBRI)- LISBOA-01- 0145-FEDER-022059 funded by the European Regional Development Fund (ERDF) under the scope of Norte2020 - Programa Operacional Regional do Norte, info:eu-repo/semantics/publishedVersion

The main goal of this study was to chemically characterize an aqueous S. nigra flower extract and validate it as a bioactive agent. The elderflower aqueous extraction was performed at different temperatures (50, 70 and 90 °C). The extract obtained at 90 °C exhibited the highest phenolic content and antiradical activity. Therefore, this extract was analyzed by GC-MS and HPLC-MS, which allowed the identification of 46 compounds, being quercetin and chlorogenic acid derivatives representative of 86% of the total of phenolic compounds identified in hydrophilic fraction of the aqueous extract. Naringenin (27.2%) was the major compound present in the lipophilic fraction. The antiproliferative effects of the S. nigra extract were evaluated using the colon cancer cell lines RKO, HCT-116, Caco-2 and the extracts antigenotoxic potential was evaluated by the Comet assay in RKO cells. The RKO cells were the most susceptible to S. nigra flower extract (IC50=1250 µg mL1). Moreover, the extract showed antimicrobial activity against Gram-positive bacteria, particularly Staphylococcus aureus and S. epidermidis. These results show that S. nigra-based extracts can be an important dietary source of bioactive phenolic compounds that contribute to health-span improving life quality, demonstrating their potential as nutraceutical, functional foods and/or cosmetic components for therapeutic purposes., This research was funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and for Scientific Employment Stimulus 2017 (CEECIND/01507/2017) provided to Ana M. Sousa., info:eu-repo/semantics/publishedVersion

Agro-food industries generate a huge amount of fruit and vegetable wastes. These residues are composed by structural parts (leaves, peels, pulps, seeds, roots and stems) after the extraction of their juices, and they are rich in bioactive compounds such polyphenols, protein, carbohydates, fibre, lignin, lipids and minerals. Therefore, these wastes constitute a source of bioactive compunds and their valorization leads to a circular economy in which industry and society benefit. Between the component of the residues, polyphenols compounds may contribute to prevent or treated cancer, neurodegenerative and cardiovascular diseases, among others. The aim of this work was the study of the potential therapeutic effect of fruit and vegetable extracts (peach, apple, cucumber and red pepper) obtained by ultrasounds, on different lines of cancer cells (colon, liver and breast) and on oxidative stress in a healthy colon. The results showed that extracts rich in polyphenols had an antiproliferativeeffect against tumor cells and their action was improved by encapsulation in maltodextrin. Encapsulation also increased the protection against oxidative stress in intestinal cells. This study opened the gate to use the extracts from fruit and vegetable wastes as pharmaceutical excipients, food additives, nutraceutical products or functional foods for therapeutic purposes and prevention of diseases related to oxidative stress., SOE1/P1/E0123 Interreg Sudoe REDVALUE, Technological Alliance to Complete the Forest and Agroindustrial Production Cycle. Authors also thank the Ministry of Economy and Innovation under Grant (SAF2016-75441-R); Aragón Regional Government (B16-20R, Fondos FEDER "Otra manera de hacer Europa") and CIBERobn under Grant (CB06/ 03/1012) of the Instituto de Salud Carlos III. Author Raquel Ibarz thanks the University of Lleida for the UdL-Impuls post-doctoral contract. In addition, 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 BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Pedro Santos is recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte, info:eu-repo/semantics/publishedVersion

Animal-based proteins are the most consumed worldwide given their well-balanced nutritional composition. However, the growing demand for animal proteins will not be sustainable due to their low conversion efficiency and high environmental footprint. Specific consumers dietary restrictions and modern trends emphasize the importance of finding alternative sustainable non-animal sources to meet future food (and, in particular, protein) global needs. Algal biomass is considered a relevant alternative, presenting advantages over terrestrial biomass such as higher growth rate, low water consumption, no competition for arable land, carbonneutral emissions, and production of numerous bioactive compounds. This review provides an overview of recent research advances on algae as source of proteins, including production strategies from relevant protein-producing species. Particular emphasis will be given to algae protein current applications and forthcoming challenges of their use. Nutritional and functional aspects of algae biomass or its protein-enriched fractions will be overviewed., This research work was supported by ALGAVALOR - Lisboa-01-0247- FEDER-035234, supported by Operational Programme for Competitiveness and Internationalization (COMPETE2020), Lisbon Portugal Regional Operational Programme (Lisboa 2020) and Algarve Regional Operational Programme (Algarve 2020) under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and with a Ph.D. scholarship - SFRH/BD/07527/2020 - and BioTecNorte operation (NORTE-01-0145-FEDER 000004) funded by the ERDF under the scope of Norte2020 - Programa Operacional Regional do Norte. Ricardo N. Pereira acknowledge FCT for its Assistant Research program under the scope of Scientific Stimulus Employment with reference CEECIND/02903/2017., info:eu-repo/semantics/publishedVersion

The aim of this work was to study the potential application of edible films obtained by complex coacervation promoted by the electrostatic interactions between positively charged chitosan (CH) 3% (w/w) and negatively charged whey protein isolate (WPI) 3% (w/w). Preliminary assays of turbidimetry were made in order to find the optimal CH-to-WPI mass ratio for the complex coacervation. The maximum turbidity was obtained in the CH:WPI mass ratio of 0.1:1 (w/w). The dispersions of CH/WPI (both at 3 % (w/w)), WPI 5 % (w/w) and CH 3% (w/w) were analyzed by Cryo-scanning electron microscopy (Cryo-SEM) and the micrograph of CH/WPI coacervate presented a more compact network structure than dispersions of individual biopolymers. The composite CH/WPI films were prepared, characterized and their performance and physicochemical properties were compared with those of CH or WPI films, in terms of water vapor permeability (WVP), mechanical properties, solubility, sorption isotherms, optical properties, scanning electron microscopy (SEM) imaging, Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). Results revealed that the incorporation of small amounts of CH in the matrix of WPI led to form a composite film with higher tensile strength, lower deformation, malleability, flexibility, solubility and WVP in comparison to the mono-component WPI and CH films. The CH incorporation resulted in a decrease in equilibrium moisture content of the CH/WPI film and the Guggenheim-Anderson-de Boer (GAB) model of sorption data indicated isotherms of type II. All the films presented a homogeneous structure, color transparency, which is desired in food applications and packaging technology., 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 and UID/QUI/50006/2020 units; the work was also supported by BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte 2020 - Programa Operacional Regional do Norte., info:eu-repo/semantics/publishedVersion

The significant increase in the world population age, 47 years in 1950 to 73 years in 2020, resulted in an increase in aging related diseases as well as in degenerative diseases. In consequence, researchers have been focusing in the development of new therapies, with a particular emphasis on the use of compounds with antioxidant properties, namely phytochemicals, such as polyphenols and carotenoids. Several in vitro and in vivo studies have demonstrated the phytochemicals antioxidant capacity. Their use is broad, as they can be part of food supplements, medicine and cosmetics. The health benefit of antioxidant phytochemicals is an indisputable question. Phytochemical properties are highly influenced by the natural matrix as well as by extraction process, which have a key role. There are several extraction methods that can be applied depending on the chemical properties of the bioactive compounds. There is a wide range of solvents with different polarities, which allows a selective extraction of the desired target family of compounds. Greener technologies have the advantage to reduce extraction time and solvent quantity in comparison to the most traditional methods. This chapter will focus on the different green extraction strategies related to the recovery of antioxidant bioactive compounds from natural sources, their nutritional and health potential.

Seaweeds are a renewable natural source of valuable macro and micronutrients that have attracted the attention of the scientists in the last years. Their medicinal properties were already recognized in the ancient traditional Chinese medicine, but only recently there has been a considerable increase in the study of these organisms in attempts to demonstrate their health benefits. The extraction process and conditions to be used for the obtention of value-added compounds from seaweeds depends mainly on the desired final product. Thermochemical conversion of seaweeds, using high temperatures and solvents (including water), to obtain high-value products with more potential applications continues to be an industrial practice, frequently with adverse impact on the environment and productsâ functionality. However more recently, alternative methods and approaches have been suggested, searching not only to improve the process performance, but also to be less harmful for the environment. A biorefinery approach display a valuable idea of solving economic and environmental drawbacks, enabling less residues production close to the much recommended zero waste system. The aim of this work is to report about the new developed methods of seaweeds extractions and the potential application of the components extracted., This work was funded by the Portuguese Foundation for Science and Technology (FCT) un der the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte. The work was also supported by the Euro pean Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant (MSCA-RISE; FODIAC; 778388). Gabriela Matos is recipient of a PhD fellowship supported by a doctoral advanced training (call NORTE-69-2015-15), funded by the European Social Fund under the scope of Norte2020—Programa Operacional Regional do Norte (NORTE-08-5369-FSE-000036). Sara Pereira and Zlatina Genisheva are supported by the project OH2O (POCI-01-0145-FEDER 029145) funded by FCT and Fundo Europeu de Desenvolvimento Regional (FEDER) under the scope of Programa Operacional de Competividade e Internacionalização (POCI)-COMPETE 2020 and Portugal 2020., info:eu-repo/semantics/publishedVersion

Polyphenolic extracts from pine bark have reported different biological actions and promising beneficial effects on human health. However, its susceptibility to environmental stresses (temperature, storage, etc.) and physiological human conditions prequires the development of efficient protection mechanisms to allow effective delivering of functionality. The aim of this work was to encapsulate pine bark extract rich phenolic compounds by spray-drying using maltodextrin, and understand the influence of encapsulation on the antioxidant and antimicrobial activity and bioaccessibility of phenolic compounds during gastrointestinal digestion. The optimized process conditions allowed good encapsulation efficiency of antioxidant phenolic compounds. The microencapsulation was effective in protecting those compounds during gastrointestinal conditions, controlling their delivery and enhancing its health benefits, decreasing the production of reactive oxygen species implicated in the process of oxidative stress associated with some pathologies. Finally, this encapsulation system was able to protect these extracts against acidic matrices, making the system suitable for the nutritional enrichment of fermented foods or fruit-based beverages, providing them antimicrobial protection, because the encapsulated extract was effective against Listeria innocua. Overall, the designed system allowed protecting and appropriately delivering the active compounds, and may find potential application as a natural preservative and/or antioxidant in food formulations or as bioactive ingredient with controlled delivery in pharmaceuticals or nutraceuticals., This research was funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020-Programa Operacional Regional do Norte. The study was also supported by program INTERREG V-B Sudoe (REDVALUE, SOE1/P1/E0123) and by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant (MSCARISE; FODIAC; 778388). P.F.-S. is supported by a doctoral advanced training fellowship (call NORTE69-2015-15), funded under the scope of Norte2020 (NORTE-08-5369-FSE-000036). R.I. thanks the University of Lleida for the UdL-Impuls post-doctoral contract., info:eu-repo/semantics/publishedVersion

A sequential multi-stage procedure was applied on the extraction of biocompounds from Spirulina platensis. The process consisted in three steps: 1) aqueous extraction, using conventional thermal extraction (CE), ohmic heating (OH, 7V/cm), enzymatic treatment (EAE, 0.8 mgLysozyme/mL), or both OH and EAE combined; 2) ethanolic extraction; 3) CHCl3/MeOH extraction. The results evidenced that the combined OH-EAE extraction allowed selective recovery of phycobiliproteins in the 1st step, with increments of more than 100% in yield in comparison with CE. Pigments and lipids were selectively extracted in the 2nd step. The combination of OH and EAE in the 1st step resulted in higher amounts of extracted compounds in the following phases compared to processes using non-combined technologies. Results demonstrate that the intensification of extraction steps facilitates the use of environmentally friendly technologies in a multi-stage process capable of recovering and isolating different fractions with bio-functional properties, targeting waste reduction and circular economy. Industrial relevance Spirulina plantensis represents a potential biomass feedstock due to its potential as a source of compounds of great economic value (including antioxidants, proteins, lipids and natural pigments, in particular blue colorants). The combined use of ohmic heating and enzymes in the aqueous extraction step fosters the use of environmentally friendly technologies to implement sequential high yield and high purity extraction of the different valuable fractions with bio-functional properties, targeting waste reduction and contributing to the implementation of circular economy strategies. This can be integrated with a design of Industry 4.0 driving the development of new products., This research was funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, by program Marie Skłodowska-Curie grant (MSCA-RISE; FODIAC; 778388) and by project OH2O - POCI-01-0145-FEDER-029145 (funded by FCT, COMPETE2020 – Competitiveness and Internationalization Operational Program and European Fund for Regional Development - FEDER). Pedro Santos is recipient of a PhD fellowship supported by a doctoral advanced training (call NORTE-69-2015-15), funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte (NORTE-08-5369-FSE-000036). Sílvia Miranda acknowledges the financial support provided by FCT through the Doctoral grant SFRH/BD/144188/2019. Spirulina platensis was kindly supplied by EVRA S.r.l. (Potenza, Italy)., info:eu-repo/semantics/publishedVersion

In Europe, pine forests are one of the most extended forests formations, making pine residues and by-products an important source of compounds with high industrial interest as well as for bioenergy production. Moreover, the valorization of lumber industry residues is desirable from a circular economy perspective. Different extraction methods and solvents have been used, resulting in extracts with different constituents and consequently with different bioactivities. Recently, emerging and green technologies as ultrasounds, microwaves, supercritical fluids, pressurized liquids, and electric fields have appeared as promising tools for bioactive compounds extraction in alignment with the Green Chemistry principles. Pine extracts have attracted the researchers’ attention because of the positive bioproperties, such as anti-inflammatory, antimicrobial, anti-neurodegenerative, antitumoral, cardioprotective, etc., and potential industrial applications as functional foods, food additives as preservatives, nutraceuticals, pharmaceuticals, and cosmetics. Phenolic compounds are responsible for many of these bioactivities. However, there is not much information in the literature about the individual phenolic compounds of extracts from the pine species. The present review is about the reutilization of residues and by-products from the pine species, using ecofriendly technologies to obtain added-value bioactive compounds for industrial applications., This work was funded by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte and by program INTERREG V-B Sudoe (REDVALUE, SOE1/P1/E0123). Zlatina Genisheva is supported by the project OH2O (POCI-01-0145-FEDER-029145) funded by FCT and Fundo Europeu de Desenvolvimento Regional (FEDER) under the scope of Programa Operacional de Competividade e Internacionalizaçao (POCI)-COMPETE 2020 and Portugal 2020. Elisa Zanuso is recipient of a PhD fellowship supported by the Mexican Science and Technology Council (CONACYT ID 639021/495314). Pedro Santos is recipient of a PhD fellowship supported by a doctoral advanced training (call NORTE-69-2015-15), funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte (NORTE-08-5369-FSE-000036)., info:eu-repo/semantics/publishedVersion

Electric field-based technologies for extraction processes have been gaining importance due to sustainability concerns. This work aims to assess the potential of ohmic heating as an efficient and feasible tool for the extraction of different biocompounds from Gracilaria vermiculophylla and its effect on the extracts' composition. Different ratios of water/ethanol (0 to 75% ethanol, v/v) were used to target different families of biocompounds. The ohmic heating-based extraction was performed at 82 °C under electric field and frequency of 28 V/cm and 25 kHz, respectively. Conventional extractions without the presence of electric field were made keeping a temperature profile identical to the ohmic heating treatments, thus addressing the potential occurrence of electrical (non-thermal) effects. Extraction yields and extracts composition (content in polysaccharides, proteins, phenolic compounds and pigments) were evaluated. Further, as agar is the major commertially exploited compound from Gracilaria spp., the effect of ohmic heating on the extracted agar in terms of yield, carbohydrates' composition, monosaccharides profile, and gelling ability was also envisaged. Overall, significant differences in the extraction of each family of compounds between ohmic and conventional extractions were observed, being more pronounced at the best solvent for each compound (100% water for carbohydrates, 75:25 water/ethanol for proteins, 75:25 and 50:50 water/ethanol for phenolic compounds and 25:75 water/ethanol for pigments). Higher extraction yields were achieved for ohmic heating at 1 h, except for 100% water, probably indicating accelerated extraction kinetics promoted by the presence of electric field effects. Furthermore, the gelling ability of agar and the antioxidant activity were not impaired by the use of moderate electric fields. Therefore, ohmic heating is an interesting alternative, with reduced energy consumption and improved extraction performances, to recover functional ingredients or additives from seaweeds for the food industry., This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of project OH2O – PTDC/EQU/029145/2017 and the strategic funding of UID/BIO/04469/2019 unit, and by the European Fund for Regional Development (FEDER) and COMPETE 2020 – Competitiveness and Internationalization Operational Program under the scope the projects OH2O (POCI-01-0145-FEDER 029145) and VALORMAR – Full valorization of marine resources: po tential, technological innovation and new applications (call 10/SI/2016; reference: 24517). This work was also developed within the scope of the stratigic funding of CICECO-Aveiro Institute of Materials (UIDB/50011/2020 & UIDP/50011/2020), QOPNA (UID/QUI/00062/2019) and LAQV-REQUIMTE (UIDB/50006/2020), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. This work was also funded by national funds (OE), through FCT, I.P., within the scope of the frame work contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19., info:eu-repo/semantics/publishedVersion

Spirulina platensis is interesting for the food industry due to its overall composition and high content in C-phycocyanin. However, the sensitivity of C-phycocyanin makes its extraction a delicate process. The present study focuses on assessing the use of ohmic heating (OH) in the recovery of C-phycocyanin and other relevant compounds as an alternative method to freeze-thawing or conventional heating. Different ohmic and conventional heating treatments were applied both to purified C-phycocyanin and Spirulina powder. Evaluation of fluorescence and circular dichroism showed that moderated electric fields increased C-phycocyanin stability. This was confirmed in the extraction trials which revealed that OH assisted extraction at higher temperatures (44°C), and shorter times (30min) allowed significant higher extraction yield of C-phycocyanin (45 mg/gdw Spirulina), in comparison with conventional heating and freeze-thawing. OH allowed also up to 80% higher yields in phenolic compounds and carbohydrates., 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 BioTecNorte operation (NORTE-01-0145-FEDER000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The study was also supported by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant (MSCA-RISE; FODIAC; 778388) and project OH2O – POCI-01-0145-FEDER-029145 (FCT and COMPETE2020). Pedro Santos is recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15), funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte (NORTE-08-5369-FSE-000036)., info:eu-repo/semantics/publishedVersion

The agricultural and processing activities of olive crops generate a substantial amount of food by-products, particularly olive leaves, which are mostly underexploited, representing a significant threat to the environment. Olive leaves are endowed with endogenous bioactive compounds. Their beneficial/health-promoting potential, together with environmental protection and circular economy, merit their exploitation to recover and reuse natural components that are potentially safer alternatives to synthetic counterparts. These biomass residues have great potential for extended industrial applications in food/dietary systems but have had limited commercial uses so far. In this regard, many researchers have endeavoured to determine a green/sustainable means to replace the conventional/inefficient methods currently used. This is not an easy task as a sustainable bio-processing approach entails careful designing to maximise the liberation of compounds with minimum use of (i) processing time, (ii) toxic solvent (iii) fossil fuel energy, and (iv) overall cost. Thus, it is necessary to device viable strategies to (i) optimise the extraction of valuable biomolecules from olive leaves and enable their conversion into high added-value products, and (ii) minimise generation of agro-industrial waste streams. This review provides an insight to the principal bioactive components naturally present in olive leaves, and an overview of the existing/proposed methods associated with their analysis, extraction, applications, and stability., FCT -Fundação para a Ciência e a Tecnologia(UID/BIO/04469/2020), info:eu-repo/semantics/publishedVersion

The production of energy and chemicals from renewable biomass provides an ideal alternative to petroleum-based refinery reducing the dependence on fossil-fuel resources and contributing to the decarbonization and sustainable growth of the society. Lignocellulosic-based wastes have been recognized as the most important renewable source, not competing with food crops. In this sense, the valorization of lignocellulosic-based wastes for the production of value-added compounds contributes for achieving a circular economy, which aims to develop new income streams by the creation of novel sectors, adding value to products and promoting jobs. Lignocellulosic biomass is mainly composed by nonstructural components (such as extractives, ash, protein, and other minor components) and structural components (cellulose, hemicellulose, and lignin). The selective fractionation of lignocellulosic-based wastes allows the use of separate fractions for a suitable and specific application. This approach is known as lignocellulosic biorefinery. This chapter will approach the main commercial products obtained from lignocellulosic components and the biomass sources for the extraction of these fractions. Moreover, the most important applications of these biomass-derived products will be addressed, as well as some more recent techniques of processing for the extraction of extractives, cellulose, hemicellulose, and lignin.

Pinus pinaster (pine) bark is a widely available wood industry byproduct but an underexploited source of phenolic compounds with a strong antioxidant activity. The aim of this study was to evaluate the effectiveness of ohmic heating (OH, a recognized eco-friendly, electric fields-based processing technology) for the sustainable recovery of phenolic compounds from Pinus pinaster bark. Results of OH evidenced increased extraction of antioxidant phenolic compounds with no degradation of pine bark extracts for all tested conditions. Moreover, the enhancement in phenolic content in OH-assisted extraction was particularly evident when using a hydroethanolic solvent with 50% ethanol, reaching improvements higher than 100%, when comparing to the conventional approach. This fact may indicate preferential extraction, presumably due to the action of electric field effects acting in synergy with heat and solvents. Furthermore, additional changes in the morphological structure of bark cells were observed upon OH-assisted extraction, suggesting membrane electroporation effects. A significant reduction in energy consumption when compared with the conventional process was observed, leading to an energetically more sustainable approach. OH technology holds the potential to be a “green” alternative, with higher extraction yields and reduced energy consumption and offering the possibility of tuning the selectivity toward phenolic compounds., This work was supported by the Portuguese Foundation for Science and Technology - FCT (under the scope of the strategic funding of UID/BIO/04469/2019 unit and project 029145), COMPETE 2020 (POCI-01-0145-FEDER-029145), BioTecNorte operation (NORTE-01-0145-FEDER-000004, funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte), and by program INTERREG V-B Sudoe (RED VALUE, SOE1/P1/E0123). P.S. is the recipient of a fellowship supported by a doctoral advanced training (NORTE-08-5369-FSE-000036, call NORTE-69-2015-15), funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. Z.G. is the recipient of a fellowship supported by FCT (SFRH/BPD/108868/2015)., info:eu-repo/semantics/publishedVersion

Made available in DSpace on 2018-12-11T16:58:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-03-01 Locust bean gum synergistic interactions with whey proteins are widely described in terms of functional properties. The aim of this work is to assess how these interactions affect whey protein-based film properties. Blended films were manufactured using whey protein isolate (WPI), four different concentrations levels of locust bean gum (LBG) and two different thermal treatments. A rheological study was performed to assess interaction between WPI and LBG. The influence of glycerol on WPI/LBG interactions was also verified. Barrier, mechanical, and optical properties, as well as microstructure, solubility and moisture sorption behavior of films were evaluated. The results show that interaction between WPI and LBG and more severe heat treatments provide stronger, more flexible and less soluble films with lower permeability to carbon dioxide and oxygen and lower transparency. These findings suggest that the addition of locust bean gum to WPI can be used to tune the properties of WPI-based edible films to meet specific food packaging and edible coating needs. REQUIMTE, LAQV, Departamento de Engenharia Química, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias Department of Food Engineering and Technology, Institute of Biosciences, Language and Physical Sciences (IBILCE), UNESP - São Paulo State University, Rua Cristóvão Colombo 2265 Department of Food Engineering and Technology, Institute of Biosciences, Language and Physical Sciences (IBILCE), UNESP - São Paulo State University, Rua Cristóvão Colombo 2265

Supplementary data to this article can be found online at https://doi.org/10.1016/j.jcs.2020.103039., Rice bran (RB) is an important by-product from the rice production with a high valorization potential. The aim of the present work was to explore this potential by considering combined protein and phenolic fractions and enzymatic hydrolysis. The influence of different protocols in the recovery/fractioning of protein were evaluated, including defatting procedures, in rice brans from two very different locations: Portugal and Colombia. The different protein fractions achieved were characterized. Proteins were further hydrolyzed using trypsin and their hydrolysates were characterized in terms of degree of hydrolysis and peptide size. Moreover, the total phenolic content (TPC) and phenolic compoundsâ profile on extracted fractions and hydrolysates of RB from Portugal and Colombia were determined. The functional potential was assessed in terms of antioxidant and antihypertensive activities. Though the protein concentrates had already significant potential bioactivities, protein hydrolysates showed that the TPC, antioxidant and antihypertensive activities significantly increased with the digestion by trypsin. Hydrolysates of RB from Portugal presented a higher antioxidant and hypertensive activities in comparison with hydrolysates of RB from Colombia, moreover it presented a higher content of TPC. This study indicated that the exploitation potential of rice bran can be increased with simple fractioning procedures, that combined protein/phenolic fractions are important to deliver functionality and that hydrolysis can be a relevant tool to release that functionality. Furthermore, regional differences in rice bran composition are also important factors to consider. Overall, this knowledge can be used to increase the industrial potential of valorization for this by-product., The authors acknowledge the financial support of the National University of Colombia, call to International Mobility 2017–2018, COLCIENCIAS call 727 National Doctorates, the ErasmusþProgramme Key Action 1, the Portuguese Foundation for Science and Technology FCT under the scope of the strategic funding of UID/BIO/04469/2019 unit, the European Regional Development Fund and the European Social Fund under the scope of Norte 2020 - Programa Operacional Regional do Norte (BioTecNorte operation - NORTE-01-0145-FEDER-000004 and doctoral advanced training call NORTE-69-2015-15 - ref. NORTE-08- 5369-FSE-000036)., info:eu-repo/semantics/publishedVersion

Ohmic heating (OH) technology finds today several applications in innovative food processing. Its ability to provide a fast, direct, and volumetric heating brings several processing advantages at industrial scale regarding energetic efficiency and quality of food products. Over the last years the way how electric variables, such as electric field intensity, and frequency, interact with macromolecules and microorganism has also been investigated bringing new insights regarding nonthermal microbial inactivation, enzymatic reactions, and protein functionalization, among others. The unique synergy between heat and electric effects brings exciting opportunities in the optimization of solidliquid extraction processes for the recovery of bioactive compounds. OH presents today an interesting flexibility and easiness of application being expected a natural increase of commercial food products but also an accentuated interest in of bioprocessing applications aiming transformation and selective extraction of valuable biomolecules., This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. R. Rodrigues is grateful to FCT grant (SFRH/BD/110723/2015)., info:eu-repo/semantics/publishedVersion

Concerns about fossil fuels depletion has led to seek for new sources of energy. The use of marine biomass (seaweed) to produce biofuels presents widely recognized advantages over terrestrial biomasses such as higher production ratio, higher photosynthetic efficiency or carbon-neutral emissions. In here, interesting seaweed sources as a whole or as a residue from seaweed processing industries for biofuel production were identified and their diverse composition and availability compiled. In addition, the pretreatments used for seaweed fractionation were thoroughly revised as this step is pivotal in a seaweed biorefinery for integral biomass valorization and for enabling biomass-to-biofuel economic feasibility processes. Traditional and emerging technologies were revised, with particular emphasis on green technologies, relating pretreatment not only with the type of biomass but also with the final target product(s) and yields. Current hurdles of marine biomass-to-biofuel processes were pinpointed and discussed and future perspectives on the development of these processes given., Authors are grateful to Spanish Ministry of Economy and Competitiveness (research project “Multistage processes for the integral benefit of macroalgae and vegetable biomass” with reference CTM2015-68503) and to the CITACA Strategic Partnership ED431E 2018/07 (Xunta de Galicia, Spain), these programs partially funded by FEDER of European Union. Pablo G. del Río is grateful to the Ministry of Science, Innovation and Universities of Spain for his FPU research grant (FPU16/04077). This study was supported by the Portuguese Foundation for Science and Technology (FCT, Portugal) under the scope of the strategic funding of UID/BIO/04469/2019 unit, the BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte, the MultiBiorefinery project (POCI01–0145-FEDER-016403), the AlgaePlas (FCT, project PTDC/BII-BIO/29242/2017) and the Biomass and Bioenergy Research Infrastructure (PINFRA/22059/2016)., info:eu-repo/semantics/publishedVersion

This review provides an overview of recent research on electrotechnologies applied to the valorization of bioresources. Following a comprehensive summary of the current status of the application of well-known electric-based processing technologies, such as pulsed electric fields (PEF) and high voltage electrical discharges (HVED), the application of moderate electric fields (MEF) as an extraction or valorization technology will be considered in detail. MEF, known by its improved energy efficiency and claimed electroporation effects (allowing enhanced extraction yields), may also originate high heating rates ohmic heating (OH) effect allowing thermal stabilization of waste stream for other added-value applications. MEF is a simple technology that mostly makes use of green solvents (mainly water) and that can be used on functionalization of compounds of biological origin broadening their application range. The substantial increase of MEF-based plants installed in industries worldwide suggests its straightforward application for waste recovery., This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/ BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER006684) and by BioTecNorte operation (NORTE-01-0145-FEDER000004) funded by the European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. Pedro Santos is recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15), funded by the European Social Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. Zlatina Genisheva, Rui Rodrigues and Ricardo Pereira are recipient of a fellowship supported by FCT (SFRH/BPD/ 108868/2015, SFRH/BD/110723/2015 and SFRH/BPD/81887/2011, respectively)., info:eu-repo/semantics/publishedVersion

Adverse drug reactions (ADR) are a public health problem. They cause significant morbidity, mortality and health costs. Less is known about pediatric ADR. Our goal was to characterize a pediatric case series of ADR reported to the Portuguese Pharmacovigilance System (PPS) during the past 10 years.Retrospective analysis of ADR reports concerning patients till 17 years old received by the PPS between 2003 and 2012. We evaluated patients' demographic data and involved drugs, as well as characteristics and seriousness of reactions, stratified by age groups.We found 1742 reports (50% females) corresponding to 9.7% of the total received. The age of the patients varied from 0 to 17 years (median: 5 years, interquartile range: 10.6), with 566 cases (32%) occurring in patients younger than 2y. Among the 1195 serious cases, 31% (370) episodes led to hospitalization. In 32 cases (2%) there was a fatal outcome. Most of the ADR reported referred to general disorders and administration site conditions, followed by skin and subcutaneous tissue reactions. Vaccines were the most represented group (42%) followed by antibacterials for systemic use (17%).Pediatric ADR represents about 10% of the reports received by the PPS. Most ADR were considered serious. Major findings varied according to age groups.

The economic importance of fresh-cut fruit market is becoming progressively more significant, while the food industry shows increased interest in innovation of products bringing health benefits. The objective of this work was to assess the potential of incorporating ferulic acid (antioxidant with reported bioactivity that can act as cross-linking agent) in soy protein-based edible coating formulations in order to increase the quality and shelf life of fresh-cut apples (cv. Golden). Glycerol was used as plasticizer and ferulic acid was incorporated in concentrations between 1.0 and 4.0 g L?1. The properties of fresh-cut apples were analysed during seven days of storage at 10 °C. A common commercial antioxidant (sodium ascorbate at 10 g L?1) was tested for comparison. Uncoated apples and apples dipped into antioxidants solution were used as controls. The results emphasized the need to incorporate this phenolic antioxidant in a biopolymer matrix, due to its hydrophobic characteristics and consequently a poor dispersion along the surface of the fruit. They also indicate that the efficiency of the coatings incorporating ferulic acid is highly dependent on pH. The formulation with ferulic acid at 4.0 g L?1 and pH 7.0 has demonstrated potential application in extending the shelf life of fresh-cut apples., Thanks are due to the European Community's Seventh Framework Programme (SusFoFlex, collaborative project number 289829, KBBE.2011.2.3-03). LAQV/REQUIMTE received financial support from FCT/MEC through national funds and FEDER, under the Partnership Agreement PT2020 (reference UID/QUI/50006/2013 - POCl/01/0145/FEDER/007265)., info:eu-repo/semantics/publishedVersion

Complex coacervation between whey proteins and carboxylated or highly sulphated polysaccharides has been widely studied. The aim of this work was to characterise a slightly sulphated polysaccharide (agar) and whey protein insoluble complexes in terms of yield, composition and physicochemical properties as well as to study their rheological behaviour for better understanding their structure. Unlike other sulphated polysaccharides, complexation of agar and whey protein at pH 3 in the absence of a buffering agent resulted in a coacervate that was a gel at 20°C with rheological properties and structure similar to those of simple agar gels, reinforced by proteins electrostatically aggregated to the agar network. The behaviour towards heat treatment was similar to that of agar alone, with a high thermal hysteresis and almost full reversibility. In the presence of citrate buffer, the result was a "flocculated solid", with low water content (75-81%), whose properties were governed by protein behaviour.

To attend the growing consumer demand for novel ready-to-eat fresh cut fruits packaging polylactic acid (PLA)-based active packaging was realized. The aim of these packaging is to provide an improved protection and even to extend their shelf-life. PLA-based active packaging was prepared by adding nanoclays and surfactants in its formulation. The evaluation of PLA-nanocomposite packaging was done in comparison to pristine PLA and conventional plastic (polyethylene terephthalate, PET) using fresh-cut melons. Physicochemical properties were investigated by the means of weight loss, visual appearance, pH, colour, and firmness. In addition, microbial profile was tested via microbiological assays. In order to evaluate the environmental impact of PLA-based active packaging compared to commonly used PET, life cycle assessment (LCA) was conducted. In terms of physicochemical and antimicrobial properties, the results clearly showed that the presence of nanoclays and surfactants in the PLA formulations improved their performance, thus contributing to bring the characteristic and behaviour of PLA packages close to those of PET. Furthermore, assessment of life cycle environmental impacts indicated that PLA packaging with nanoclays had the highest environmental performance.

The aim of this work was to investigate the rheological behaviour of human blood, in a controlled stress rheometer, using different cone-plate and parallel plate geometries. Steady-shear (flow curves and kinetics) and oscillatory (strain, frequency and time sweeps) tests were performed at 37 ◦ C. The results demonstrated that rheological data are significantly influenced by the measuring geometry and the rheological parameters obtained from rheological models must be analysed with great caution. The Cross model provided a better fit of the flow curves and the Power Law model gave a better concordance between the rheological parameters obtained with the different measuring systems. The oscillatory measurements demonstrated a linear viscoelastic behaviour below a critical frequency and the Friedrich-Braun model described well the frequency sweeps experimental data in that region. The correlation between steady-shear and oscillatory properties (Cox-Merz rule) suggests that the two methods can be complementary and may give important information on red blood cells aggregation and deformability. Results from oscillatory time sweeps confirm a blood aggregation process in two steps.

The interaction with cervicovaginal mucus presents the potential to impact the performance of drug nanocarriers. These systems must migrate through this biological fluid in order to deliver their drug payload to the underlying mucosal surface. We studied the ability of dapivirine-loaded polycaprolactone (PCL)-based nanoparticles (NPs) to interact with a simulated vaginal fluid (SVF) incorporating mucin. Different surface modifiers were used to produce NPs with either negative (poloxamer 338 NF and sodium lauryl sulfate) or positive (cetyltrimethylammonium bromide) surface charge. Studies were performed using the mucin particle method, rheological measurements, and real-time multiple particle tracking. Results showed that SVF presented rheological properties similar to those of human cervicovaginal mucus. Analysis of NP transport indicated mild interactions with mucin and low adhesive potential. In general, negatively charged NPs underwent subdiffusive transport in SVF, i.e., hindered as compared to their diffusion in water, but faster than for positively charged NPs. These differences were increased when the pH of SVF was changed from 4.2 to 7.0. Diffusivity was 50- and 172-fold lower in SVF at pH 4.2 than in water for negatively charged and positively charged NPs, respectively. At pH 7.0, this decrease was around 20- and 385-fold, respectively. The estimated times required to cross a layer of SVF were equal to or lower than 1.7 h for negatively charged NPs, while for positively charged NPs these values were equal to or higher than 7 h. Overall, our results suggest that negatively charged PCL NPs may be suitable to be used as carriers in order to deliver dapivirine and potentially other antiretroviral drugs to the cervicovaginal mucosal lining. Also, they further reinforce the importance in characterizing the interactions of nanosystems with mucus fluids or surrogates when considering mucosal drug delivery.

Chitosan packaging films containing different bioactive compounds (a peptide fraction from whey protein concentrate (WPC) hydrolysate, glycomacropeptide (GMP) and lactoferrin) were produced and their mechanical and barrier properties were evaluated. The molecular weight of protein-based compounds was determined using SDS–PAGE. The addition of GMP and lactoferrin to chitosan film caused a significant reduction of tensile strength and the elongation-at-break significantly increased with the incorporation of lactoferrin. The addition of protein-based compounds also affected gas permeability: a significant decrease in water vapor permeability was observed with the incorporation of lactoferrin; oxygen permeability significantly decreased with the addition of GMP and lactoferrin and carbon dioxide permeability significantly decreased with the incorporation of all of the protein-based compounds. Such results were related with film’s hydrophilicity and crystallinity. This manuscript contributes to the establishment of an approach to optimize edible films performance based on physico-chemical properties, aiming at a higher benefit for the consumer., The authors gratefully acknowledge LoicHilliou for the fruitful discussions on the results and Ana Nicolau for helping in confocal analysis. The present work was supported by the project PTDC/AGR/ALI/67194/2006. The authors M.A. Cerqueira (SFRH/BD/23897/2005), M.C. Avides (SFRH/BPD/26913/2006) and M.A.C. Quintas (SFRH/BPD/41715/2007) were recipient of fellowships from the Fundacaopara a Ciencia e Tecnologia (FCT, Portugal).

Determination of material properties and functions is a crucial step towards optimization of fabrication methods as well as the development of electrospun nanofibers for use in e.g. food engineering applications. This work focused in evaluating physical and mass transfer properties of simple poly -caprolactone nanofibers (PCL membrane), and poly ε-caprolactone nanofibers with encapsulated trypsin (E-PCL membrane), in view of their future use in a catalytic filter reactor. PCL membranes registered high hydrophobicity values, while E-PCL membranes revealed stronger mechanical properties and an increase of mass due to water incorporation. A decrease of average pore size in the range of 30% to 40% was observed for E-PCL membranes and an average pore diameter of 1/3 of the size was registered when compared to the PCL membrane; this difference was shown to be significant enough to influence the transport of larger molecules (e.g. bovine serum albumin). Release experiments of active compounds (lysozyme, bovine serum albumin and lactoferrin) were successfully described by a model which accounts for both Fick and Case II transport the linear superimposition model. Results show that the transport mechanism is influenced by the type of active compound and by membranes physical properties., The present study was developed under the scope of the NanoBioCats project (PTDC/CTM-POL/112289/2009), funded by the Portuguese Science and Technology Foundation (Fundação para a Ciência e a Tecnologia – FCT). This work was also supported by the COMPETE program (funded by the European Union fund, FEDER under the framework of QREN (Programa Operacional Regional do Norte (ON.2 – O Novo Norte; FEDER))) through projects NORTE-07-0124-FEDER-000028 and NORTE-07-0124-FEDER-000069. Also, the authors thank Strategic Projects PEst-OE/EQB/LA0023/2013, PEst-C/EQB/LA0006/2013 – FCOMP-01-0124-FEDER-37285 and PEst-C/QUI/UI0062/2013 – FCOMP-01-0124-FEDER-037296. The Fundação para a Ciência e Tecnologia (FCT, Portugal) through grant SFRH/BD/73178/2010

The aim of this work was to assess the possibility of using beer spent grain (a byproduct of beer’s brewing industry) as a carrier for laccase immobilization. Both adsorption (on spent grain – SG and on digested spent grain – DSG) and covalent binding (using glycidol and glycidol followed by ethylenediamine on DSG) were used. The effect of different immobilization conditions on the immobilization yields and recovered activities such as contact time, enzyme concentration and pH was evaluated. For the best conditions, immobilization yields, recovered activities and thermal, operational and storage stabilities were also evaluated. Finally, the Michaelis–Menten mechanism was applied and the parameter with respect to ABTS oxidation was determined. Enzyme immobilization on DSG led to the best enzyme activities (recovered activities as high as 90%) and to high storage and operational stabilities (10 cycles). Thermal stability was also improved and the half-life of immobilized laccase in SG increased from 0.64 h to 1.1 h at 70 ◦C, A.M. Silva thanks Fundacao para a Ciencia e Tecnologia (FCT, Portugal) for the Scholarship (BII/LAB/0020/2009). A.P.M. Tavares acknowledge the financial support (Programme Ciencia 2008) from FCT. This work is supported by projects PEst-/EQB/LA0020/2011 and PEst-/EQB/LA0006/2011, financed by FEDER through COMPETE - "Programa Operacional Fatores de Competitividade" and by FCT.

With increasing demand for sustainable materials, keratin wastes have been regarded, in recent years, as renewable resources worthy of exploitation. Each year, the Portuguese leather industry discards a considerable amount of animal hair, which constitutes a troublesome waste product. In this study, in an attempt to find a potential utilization for this waste, the preparation of biodegradable films from bovine hair, by thermo-compression, was tested. Bovine hair formulations with 20, 30 and 40 wt % of plasticizer (glycerol, lactic acid) were pressed into films, at 147 kN and 120oC or 160oC for 4 minutes. The mechanical properties, colour, solubility and water sorption isotherms of the obtained films were assayed. All films were opaque and dark. Solubility was higher for films processed at higher temperature and with lactic acid as plasticizer. The Guggenheim-Anderson-de Boer (GAB) model gave a good fit to the experimental results for the moisture sorption isotherms. The stress at break, , and the Young’s modulus, E, decreased and the strain at break, , increased with the addition of increasing amounts of plasticizer.

Currently, mainly non-biodegradable petroleum-based synthetic polymers are used as packaging materials for foods, because of their availability, low cost and functionality. However, biodegradable/edible films can be made from polysaccharides, proteins and lipids without the environmental issues of petroleum-based polymers and with the additional advantage of being available from renewable sources or as by-products or waste-products from the food and agriculture industries. Although these sources are not enough, by far, to replace the synthetic polymers/films, they can help in reducing packaging wastes and can replace them in specific applications. Proteins have the extra advantage of allowing a wider range of functional properties than polysaccharides and lipids. This is conferred by their composition based on combinations of 20 different amino acids, which usually allows high intermolecular binding. This chapter starts by describing the main protein sources used in packaging materials, followed by a section dealing with materials processing and characterization. The chapter ends with an overview of current and foreseen applications. Nanotechnology applications through the utilization of materials at the nano-scale size in protein-based films are a valuable alternative for the improvement of the properties of packaging materials (water vapour transmission, mechanical, thermal). In particular, nanofilms and multi-nanolayer films constitute promising solutions for food applications using protein-based materials.

The aims of this work were to establish an efficient protocol for trypsin immobilization on spent grains and to assess the influence of the chosen protocol on whey protein hydrolysis. Trypsin was immobilized onto spent grain or modified spent grain, through adsorption and covalent attachment. The efficiency of immobilization and operation and storage stabilities of free and immobilized enzyme on the supports were studied. The enzyme activity, kinetic parameters and the peptide profile of the protein hydrolysates from free and immobilized enzyme were also analysed. The best activity retention was achieved with the immobilization on spent grains through multipoint covalent attachment using glycidol. This carrier showed also very good storage and operational stability (above 90%). Trypsin immobilized on spent grains showed significant activity towards whey proteins. The immobilized enzyme was slightly more stable than the free enzyme at temperatures between 50 ◦C and 60 ◦ C allowing its use at a broader range of temperatures. The peptides formed with free enzyme and enzyme immobilized on spent grains were generally similar. However, significant differences existed in the amount of native proteins in the hydrolysates and in the relative amount of smaller peptides. © 2010 Elsevier Ltd. All rights reserved.

The gelling ability of whey proteins can be changed by limited hydrolysis and by the addition of other components such as polysaccharides. In this work the effect of the concentration of locust bean gum (LBG) on the heat-set gelation of aqueous whey protein hydrolysates (10% w/w) from pepsin and trypsin was assessed at pH 7.0. Whey protein concentrate (WPC) mild hydrolysis (up to 2.5% in the case of pepsin and 1.0% in the case of trypsin) ameliorates the gelling ability. The WPC synergism with LBG is affected by the protein hydrolysis. For a WPC concentration of 10% (w/w), no maximum value was found in the G ′ dependence on LBG content in the case of the hydrolysates, unlike the intact WPC. However, for higher protein concentrations, the behaviour of gels from whey proteins or whey protein hydrolysates towards the presence of LBG becomes very similar. In this case, a small amount of LBG in the presence of salt leads to a big enhancement in the gel strength. Further increases in the LBG concentration led to a decrease in the gel strength.

This study describes the characterisation of whey protein hydrolysates obtained from tryptic hydrolysis to assess their application as ingredients with angiotensin-converting-enzyme (ACE) inhibitory action. The levels of a-lactalbumin (alpha-la) and P-lactoglobulin (beta-lg) remaining after hydrolysis were quantified. Peptides were separated by RP-HPLC, and Ala-Leu-Pro-Met-His-Ile-Arg (ALPMHIR), the most potent beta-lg-derived ACE-inhibitory peptide was monitored. A correlation curve was established for the production of this peptide as a function of hydrolysis time. Heat-induced gelation of hydrolysates was studied by small-deformation rheology. The gelation times and the strength of the final gels were highly dependent on the degree of hydrolysis. Smaller peptides liberated by hydrolysis contributed to the inability of whey protein hydrolysates to gel. (c) 2006 Elsevier Ltd. All rights reserved.

Hydrolysis of whey protein concentrates (WPCs) was performed using trypsin under different combinations of temperatures and pH values in a total of three experiments, namely experiment A at 37 ºC and pH 8, experiment B at 37 ºC and pH 9, and experiment C at 50 ºC and pH 8. Monitorization of the degradation of native whey proteins and the peptide formation throughout hydrolysis was performed by reverse phase HPLC/UV. Seven main peptides were separated according to their polarity and numbered from T1 to T7. In general a difference was observed between rate of hydrolysis of α-lactalbumin and β-lactoglobulin; in the former case hydrolysis was complete by 15 min in experiments B and C and by 120 min in experiment A, whereas in the later case the rate of hydrolysis was much slower. ANOVA analysis, performed to assess whether the average values obtained for the three experiments conducted to statistically different results for each variable (% of β-lactoglobulin degradation and % of peptides T1 to T7), showed significant differences between experiments A and C. However, between A and B and between B and C no significant differences were observed. Principal Component Analysis evidenced the time period at which similarities and/or differences between experiments were observed. Additionally, a mathematical equation for the degradation of β-lactoglobulin as a function of hydrolysis time was established and some peptides were correlated with their parental protein using linear regression analysis., Fundação para a Ciência e a Tecnologia (FCT)