Partículas de gel biopoliméricas para aplicações alimentares e farmacêuticas

National Patent (INPI)info:eu-repo/semantics/publishedVersio

Incorporation of functional compounds in edible packaging materials for food applications: influence in materials' properties

Edible packaging is one of the potential technologies that can be used to increase the storability of foods and to improve the existent packaging technology. Recently, edible packaging appears as an efficient vehicle for functional compounds such as antioxidants, antimicrobial and antifungal in order to enhance food stability, quality, functionality and safety. Recent developments have been achieved regarding the utilization of new materials and the study of the incorporation of functional ingredients and the their influence on relevant properties such as barrier, mechanical and surface properties. Antioxidant compounds such as extracts from Gleditsia triacanthos and -tocopherol were incorporated into galactomannan and chitosan films, respectively, and showed to influence transport, mechanical and colour properties of the films, while also promoting the antioxidant capacity of the films (1,2). The incorporation of antimicrobial compounds, such as nisin, showed to influence the properties of coatings and films, leading to the improvement of the physical properties of the films. Moreover, the obtained coatings and films showed antimicrobial activity against e.g. Listeria monocytogenes (3,4). A different behaviour was observed for the incorporation of natamycin in chitosan films were the presence of this antifungal compound lead to the increase of water vapour, oxygen and carbon dioxide permeability (5). Furthermore, the incorporation of bioactive compounds (a peptide fraction from whey protein concentrate hydrolysate, glycomacropeptide and lactoferrin) were tested in chitosan films and the results showed that the addition of protein-based compounds also affected transport properties of the films (6). Edible packaging shows suitability to incorporate functional compounds for further application in the food industry; it is also shown how the main film properties can be influenced with the incorporation of this compounds.info:eu-repo/semantics/publishedVersio

In vitro digestion of protein-based nanohydrogels incorporating curcumin as a lipophilic model compound: effect of a chitosan coating

[Excerpt] Introduction: One of the challenges of food enrichment with lipophilic bioactive compounds is related with their poor solubility in food matrices and their instability during digestion, leading to a poor bioavailability. These challenges are promoting research efforts to find more effective delivery systems based on natural biopolymers. Protein nanohydrogels can be used as carriers of bioactive compounds in food products, however, during gastric digestion, proteins are denatured by environmental conditions and hydrolyzed by enzymes. One of the strategies to improve protein nanohydrogels’ stability and the controlled release of active ingredients during gastrointestinal (GI) digestion is the addition of a coating (polysaccharide layer). The behavior of lactoferrin (Lf)–glycomacropeptide (GMP) nanohydrogels with and without a chitosan coating was evaluated during GI digestion. [...]info:eu-repo/semantics/publishedVersio

Development of lactoferrin-glycomacropetide nanohydrogels: a vehicle to encapsulate bioactive compounds

Protein-based nanohydrogels have attracted great attention due their non-toxicity, small dimension, and large interior network for multivalent bioconjugation, which offers several possibilities for the encapsulation of functional bioactive components. The aim of the current work was to develop nanohydrogels composed of lactoferrin and glycomacropeptide (GMP), and to evaluate their sensitivity to environmental stimuli and their ability to incorporate a bioactive compound. Lactoferrin and glycomacropeptide are two natural proteins with isoelectric points of 8.5 and 4.8, respectively. Lactoferrin and GMP solutions were mixed at pH 5.5, and then subsequently stirred and heated at 80 ºC during 20 min. Curcumin, a polyphenol with numerous biological and pharmacological activities, was used as bioactive compound and incorporated in the nanohydrogels. The resulting nanohydrogels were then characterized in terms of morphology (Transmission Electron Microscopy (TEM), Dynamic Scattering Light (DLS), and Atomic Force Microscopy (AFM)), stability, and curcumin binding capacity. The thermal, pH, and ionic strength stability of the nanohydrogels were evaluated during 24 wk. The results showed that nanohydrogels have a spherical shape with a hydrodynamic diameter around 170 nm and a polydispersity index of 0.1 during 24 wk. The increase in temperature (from 20 to 90 ºC) resulted in nanohydrogels with higher values of hydrodynamic diameter (from 170 to 200 nm) that returned to their initial size when the temperature returned to 20 ºC. Also, it was observed that the size and polydispersity of the nanohydrogels are influenced by pH and ionic strength. Finally, it has been shown that the nanohydrogel presents a curcumin binding capacity of 90% (mass of curcumin bound per 100 g of total curcumin). Lactoferrin-glycomacropetide nanohydrogels showed to be a good alternative to encapsulate bioactive compounds to apply in the food industry.info:eu-repo/semantics/publishedVersio

Κ-carrageenan/chitosan nanolayered coating for controlled release of a model bioactive compound

Multilayer nanocoatings composed of K-carrageenan, a sulphated anionic polysaccharide, and chitosan, a cationic polysaccharide, were produced by layer-by-layer deposition. The model cationic compound Methylene Blue (MB) was incorporated in different positions of the nanolayered coating and its loading and release behavior was evaluated. UV-VIS spectroscopy and quartz crystal microbalance analysis showed that the amount of MB loaded increased with the distance from the first layer, suggesting that the MB was able to diffuse into the K-carrageenan/chitosan nanolayered coating and not only adhered to the surface of the layer immediately below it. For most of the tested conditions, the MB release from the K-carrageenan/chitosan nanolayered coatings was successfully described by the linear superimposition model, which allowed concluding that MB transport is due to both concentration gradient and the polymer relaxation of the nanolayers. However, depending on temperature and pH of the medium and on the position of MB incorporated on the nanolayered coatings, different mechanisms prevail.Industrial relevance: The development of novel edible coatings with improved functionality and performance for e.g. fresh and minimally processed fruits is one of the challenges of the post-harvest industry. This work contributes to the understanding of the loading and release phenomena involved in structures at the nanoscale, which is useful for the development of bioactive compounds release systems for application in food industry. Moreover, the K-carrageenan/chitosan nanolayered coatings represent a promising platform from which the controlled release of different bioactive compounds may be explored.The authors Ana C. Pinheiro, Ana I. Bourbon and Mafalda A.C. Quintas are recipient of fellowships from the Fundacao para a Ciencia e Tecnologia (FCT, Portugal) through grants SFRH/BD/48120/2008, SFRH/BD/73178/2010 and SFRH/BPD/41715/2007, respectively. This work was supported by Fundacao para a Ciencia e a Tecnologia through project NANO/NTec-SQA/0033/2007. The authors also acknowledge Dr. Edith Ariza from SEMAT/UM by the support in SEM analysis

Incorporation of curcumin-loaded lactoferrin nanohydrogels into a model gelatine: release kinetics and characterization

The design and development of whey protein nanostructures as encapsulating agents for nutraceuticals controlled release has been intensively studied towards the production of functional foods. However, the interactions of these structures with food matrices are not well understood at the nanoscale and therefore they must be addressed. In this study, a curcumin- loaded lactoferrin (LF) nanohydrogel was developed aiming at its behaviour evaluation when incorporated into a model food matrix (gelatine). The release kinetics of curcumin from LF nanohydrogels added to food simulants (hydrophilic medium: ethanol 10%; and lipophilic medium: ethanol 50%) were performed at 25 °C (according to the Commission regulation EU No 10/2011). The resulting experimental data were fitted by the linear superimposition model (LSM) aiming at the evaluation of the release mechanisms of curcumin through LF nanohydrogels. This system was then incorporated into an unflavoured commercial gelatine and further characterized. For this purpose, the protein nanohydrogel isolated and loaded with curcumin was dehydrated by freeze-drying, resulting in a homogeneous LF-curcumin powder. Freeze-dried nanohydrogels were characterized by dynamic light scattering (DLS), circular dichroism (CD) and fluorometry. LF nanohydrogel showed higher release of curcumin in a lipophilic food simulant (ca. 16 g) in comparison with a hydrophilic one (ca. 1.6 g). Curcumin release kinetics through LF nanohydrogels have shown to be mainly driven by Case II transport, rather than Fickian diffusion, in both simulants. The behaviour of this system and curcumin release kinetics in food stimulants showed that LF nanohydrogel has a huge potential for the controlled release of lipophilic nutraceuticals in refrigerated food products of hydrophilic character. Finally, LF nanohydrogels were successfully incorporated in a gelatine matrix and showed no degradation in this process.FCTNORTE 2020COMPETE 2020This 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-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020, Programa Operacional Regional do Norte. Óscar L. Ramos gratefully acknowledges FCT for his financial grant with reference SFRH/BPD/80766/2011. João F. Araújo acknowledges the Escola de Ciências and Centro de Engenharia Biológica from Universidade do Minho (Braga, Portugal) for their support, under the scope of the Biophysics and Bionanosystems Master program.info:eu-repo/semantics/publishedVersio

Dehydration of protein lactoferrin-glycomacropeptide nanohydrogels

Protein based nanohydrogels have recently gained interest due their high ability to carry and deliver active compounds. However, one of the limitations of using protein-based systems is their high sensitivity to physicochemical stresses during processing and storage. Protein-based formulations are commonly prepared as solid dosage forms once their stability can be achieved in the solid rather than in the liquid state. One of the methods to improve the stability of protein-based systems is drying, being freeze and spray drying the most popular methods. Nanohydrogels composed of lactoferrin and glycomacropeptide were developed by thermal gelation and dried using a freeze-dryer (CHRIST - Alpha 14 LD plus, Germany) and a nano spray dryer B-90 (BÜCHI Labortechnik AG, Switzerland). For nano spray-drying different experimental conditions were tested such as: the inlet temperature (80, 100 and 120°C) and the hole size of the vibrating membrane in the spray cap (4m and 7m), while for freeze drying the nanohydrogels where maintained at 40°C for a drying period of about 24h. The physicochemical properties of the resulting dried nanohydrogels were compared through different techniques: differential scanning calorimetry (DSC), thermogravimetry (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). DSC shows an endothermic peak ranging from 82 to 90°C, indicating that during the drying methodologies the second denaturation peak of lactoferrin (around 90°C) is maintained. No significant differences (p<0.05) for denaturation peak temperatures were observed when different inlet temperatures or spray cap size were applied during the nano spray-drying conditions. When compared with freeze-drying it is possible to observe that a denaturation peak around the same range of temperatures was detected, also indicating that this drying process did not affect the denaturation of the protein. XRD results of nanohydrogels dried by freeze-drying revealed that crystallinity is significantly higher when compared with spray-dried nanohydrogels, explaining the lower thermal degradation observed in TGA for freeze-dried nanohydrogels. Nanohydrogels morphology after the drying process was evaluated by SEM. Nanohydrogels obtained by nano spray dryer B-90 allowed identifying the presence of particles with spherical shape, while nanohydrogels obtained by freeze drying had a sponge-like appearance. This work shows the influence of the drying process of protein-based nanohydrogels in their physical-chemical properties, thus pointing at which will be the preferred technology to be used in a future industrial application.This study was supported by the Portuguese Foundation for Science and Technology under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 e Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Low energy nanoemulsions as a carrier of thyme and lemon balm essential oils

The aim of this work was to produce monomodal and stable thyme and lemon balm-loaded nanoemulsions (NE), through a low energy approach. NEs were prepared by the emulsion phase inversion method using sunflower oil as carrier and Tween 80 as surfactant. Different surfactant-to-oil ratios (SOR) and essential oil (EO) loadings were evaluated. Nanoemulsions presented a monomodal diameter distribution below 200 nm and high negative zeta potential (>-40 mV). Nanoemulsions loaded with EOs were physically stable for 3 months at 4 degrees C and 20 degrees C. Nanoemulsions with thyme EO presented the highest radical scavenging activity by DPPH and ABTS tests. Loaded nanoemulsions were not effective against Escherichia coli but could inhibit Staphylococcus aureus. Cytotoxicity studies using cell counting kit-8 and resazurin assays revealed a dose-responsive effect of nanoemulsions on Caco-2 cells after incubation for 24 h. A concentration of 100 mu g oil/mL of NE for unloaded and thyme loaded and 50 mu g oil/mL of NE for lemon balm loaded showed to be safe to use.This research received funding from the H2020 research and inno-vation programme under the Marie Sklodowska-Curie grant agreement No 778388 (H2020 MSCA-RISE-2017, FODIAC) , and MICRODIGEST project (grant agreement 037716) co-funded by FCT and ERDF through COMPETE2020. We would like to thank the Earth Essences for its kind supply of essential oils

Lactoferrin-based nanoparticles as a vehicle for iron in food applications: development and release profile

This study aims at developing and characterizing bovine lactoferrin (bLf) nanoparticles as an iron carrier. bLf nanoparticles were characterized in terms of size, polydispersity index (PdI), electric charge (-potential), morphology, structure and stability over time. Subsequently, iron release experiments were performed at different pH values (2.0 and 7.0) at 37 °C, in order to understand the release mechanism. bLf (0.2%, w/v) nanoparticles were successfully produced by thermal gelation (75 °C for 20 min). bLf nanoparticles with 35 mM FeCl3 showed an iron binding efficiency value of approximately 20%. The nanoparticles were stable (i.e. no significant variation of size and PdI of the nanoparticles) for 76 days at 4 °C and showed to be stable between 4 and 60 °C and pH 2 and 11. Release experiments at pH 2 showed that iron release could be described by the linear superposition model (explained by Fick and relaxation phenomenon). On the contrary, the release mechanism at pH 7 cannot be described by either Fick or polymer relaxation behaviour. In general, results suggested that bLf nanoparticles could be used as an iron delivery system for future food applications.Joana T. Martins, Ana I. Bourbon and Ana C. Pinheiro acknowledge the Foundation for Science and Technology (FCT) for their fellowships (SFRH/BPD/89992/2012, SFRH/BD/73178/2010 and SFRH/BPD/101181/2014). This study was supported by FCT under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). This study was also supported by FCT under the scope of the Project RECI/BBB-EBI/0179/2012 (FCOMP-01- 0124-FEDER-027462). The authors would like to acknowledge Cristina Quintelas and Filomena Costa from CEB, University of Minho for helping with AAS and ICP analysis, respectively. Also, the authors would like to thank Rui Fernandes from IBMC, University of Porto for assistance with TEM analysi

Resveratrol-loaded octenyl succinic anhydride modified starch emulsions and hydroxypropyl methylcellulose (HPMC) microparticles: Cytotoxicity and antioxidant bioactivity assessment after in vitro digestion

Hydroxypropyl methylcellulose (HPMC)-based microparticles and modified starch emulsions (OSA-MS) were loaded with resveratrol and characterized regarding their physicochemical and thermal properties. Both delivery systems were subject to an in vitro gastrointestinal digestion to assess the bioaccessibility of resveratrol. In addition, cell-based studies were conducted after in vitro digestion and cytotoxicity and oxidative stress were assessed. HPMC-based microparticles displayed higher average sizes (d) and lower polydispersity index (PDI) (d = 948 nm, PDI < 0.2) when compared to OSA-MS-based emulsions (d = 217 nm, PDI < 0.3). Both proved to protect resveratrol under digestive conditions, leading to an increase in bioaccessibility. Resveratrol-loaded HPMC-microparticles showed a higher bioaccessibility (56.7 %) than resveratrol-loaded emulsions (19.7 %). Digested samples were tested in differentiated co-cultures of Caco-2 and HT29-MTX, aiming at assessing cytotoxicity and oxidative stress, and a lack of cytotoxicity was observed for all samples. Results displayed an increasing antioxidant activity, with 1.6-fold and 1.4-fold increases over the antioxidant activity of free resveratrol, for HPMC-microparticles and OSA-MS nanoemulsions, respectively. Our results offer insight into physiological relevancy due to assessment post-digestion and highlight the protection that the use of micro-nano delivery systems can confer to resveratrol and their potential to be used as functional food ingredients capable of providing antioxidant benefits upon consumption.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 and LAQV/REQUIMTE (UIDB/50006/2020, UIDP/50006/2020). This work was funded by the SbDtoolBox - Nanotechnology-based tools and tests for Safer-by-Design nanomaterials, with the reference NORTE-01-0145-FEDER-000047, funded by Norte 2020 – North-Regional Operational Program under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). The research also received funding from the European Union's H2020 research and innovation program under the Marie Sklodowska-Curie grant agreement N 778388 (H2020 MSCA-RISE-2017 project Food for Diabetes and Cognition (FODIAC), and grant agreement N 713640 (MSCA-2015-COFUND-FP). Pedro Silva is the recipient of a fellowship (SFRD/BD/130247/2017) supported by Fundação para a Ciência e a Tecnologia, (FCT, Portugal). Ana Isabel Bourbon acknowledges funding by FCT, through the individual scientific employment program contract (2020.03447.CEECIND). We also would like to thank the Advanced Electron Microscopy, Imaging, and Spectroscopy (AEMIS) and the Nanophotonics and Bioimaging Facility (NBI) from INL for their support