Nanoemulsions for food applications: development and characterization

The application of nanotechnology to food, medical and pharmaceutical industries has received great attention from the scientific community. Driven by the increasing consumers’ demand for healthier and safer food products and the need for edible systems able to encapsulate, protect, and release functional compounds, researchers are currently focusing their efforts in nanotechnology to address issues relevant to food and nutrition. Nanoemulsion technology is particularly suited for the fabrication of encapsulating systems for functional compounds as it prevents their degradation and improves their bioavailability. This review focuses on nanoemulsions and provides an overview of the production methods, materials used (solvents, emulsifiers and functional ingredients) and of the current analytical techniques that can be used for the identification and characterization of nanoemulsions. Finally, nanotechnological applications in foods currently marketed are reported.M.A. Cerqueira (SFRH/BPD/72753/2010) is recipient of a fellowship from the Fundacao para a Ciencia e Tecnologia (FCT, Portugal)

Erratum to Nanoemulsions for Food Applications: Development and Characterization (Food and Bioprocess Technology, (2012), 5, (854-867), 10.1007/s11947-011-0683-7)

Artigo completo publicado na revista "Food and Bioprocess Technology." 5:3 (2012) 854-867 e disponível no RepositóriUM em http://hdl.handle.net/1822/22397Where it reads: 2. Production of nanoemulsions 2.1. High-energy approaches • Ultrasound – when two immiscible liquids are submitted to high frequency sound waves in the presence of a surfactant, emulsion droplets are formed by cavitation. It should be read: 2. Production of nanoemulsions 2.2. High-energy approaches • Ultrasound – when two immiscible liquids are submitted to high intensity sound waves in the presence of a surfactant, emulsion droplets are formed by cavitation

Design and implementation of a wireless sensor network applied to motion capture

This paper describes the development of a wireless sensor network prototype and its application in a motion capture system based on inertial and magnetic sensors. The system presents a portable and modular architecture and allows the monitoring of several users at the same time using a single wireless network. The target application requires the wireless sensor network to operate efficiently under high loads, since it generates data intensive traffic and needs to support a high number of sensor modules. Other requirements imposed by the application are real-time operation and reliable data delivery. In order to provide the quality of service required by the application, an enhanced version of the LPRT medium access control protocol was developed and implemented in devices compliant with the IEEE 802.15.4 standard at the physical layer. Simulation results show that the proposed modifications improve the performance of the protocol. The implementation of the protocol is validated through the experimental results presented.Fundação para a Ciência e a Tecnologia (FCT) - projeto PTDC/EEA-TEL/68625/2006

Regime alimentar de tintureira (Prionace glauca L.) em águas Açorianas

Analisaram-se os conteúdos estomacais de 195 Prionace glauca, capturadas nos Açores entre Outubro de 1993 e Julho de 1994. Oitenta e três indivíduos possuíam estragos vazios. Apenas 23 estômagos continham animais inteiros ou semi-digeridos (excluindo o isco) pertencentes aos peixes Capros aper, Macrorhamphosus scolopax e Lepidopus caudatus e às lulas Histioteuthis bonnellii e Taonius pavo. Setenta e cinco otólitos de peixe e 207 bicos inferiores de cefalópodes foram identificados até ao género ou espécie. Considerando todos os fragmentos encontrados nos estômagos, incluindo otólitos, bicos de cefalópodes e cristalinos, foram encontrados 1411 peixes, 4 crustáceos e 261 cefalópodes. Aproximadamente 386 peixes estavam representados apenas por cristalinos. Foi encontrada uma média de 2.4 espécies (1.8 cefalópodes e 0.6 peixes) e 15.2 indivíduos por estômago. Restos de peixes foram encontrados em 83% dos estômagos analisados contribuindo em 84.5% dos animais da dieta. Restos de cefalópodes, foram encontrados em 75.7% dos estômagos e compunham 15.5% dos animais da dieta. As estimações dos pesos de peixes e cefalópodes, sugerem que os cefalópodes são, provavelmente, o grupo mais importantes na dieta de tintureira e, que são quase exclusivamente cefalópodes de flutuabilidade neutra meso- ou batipelágicos. Ocorrem pequenos cardumes de peixes epipelágicos e alguns peixes bentónicos maiores. No total, a dieta é composta por, pelo menos, 11 espécies de peixe e 37 de cefalópodes. É apresentada a distribuição de comprimentos de bicos e otólitos. Um número de espécies de cefalópodes raramente capturadas são, também, importantes para a dieta. Não foram encontradas diferenças na dieta relacionadas com o tamanho ou sexo de Prionace glauca. Comparações com a dieta de espadarte e de cachalote da mesma região sugerem claramente a existência de selecção na predação.ABSTRACT: Stomach contents of 195 Prionace glauca caught off the Azores from October 1993 to July 1994 were studied. Eighty three had empty stomachs. Only 23 contained whole or fleshy parts of animals (other than bait) and all belonged to the fish Capros aper, Macrorhamphosus scolopax and Lepidopus caudatus and the squids Histioteuthis bonnellii and Taonius pavo. Seventy five fish otoliths and 207 cephalopod lower beaks were identified to genus or species. Considering all fragments from the stomachs, including otoliths, cephalopod beaks and eye lenses, a minimum of 1411 fish, 4 crustaceans and 261 cephalopods were represented. Approximately 386 of the fish were represented by eye lenses alone. There was a mean of 2.4 species (1.8 cephalopods and 0.6 fish) and 15.2 animals represented in each stomach. Fish remains occurred in 83.0% of the stomachs and contributed 84.5% of animals to the diet. Cephalopod remains occurred in 75.7% and contributed 15.5% of animals. Estimates of the weights of fish and cephalopods suggest that cephalopods are probably the most important in the diet and these were almost entirely meso- or bathypelagic, neutrally buoyant cephalopods. Small epipelagic shoaling fish were present with a few much larger near-bottom fish. In all, there are at least 11 species of fish and at least 37 species of cephalopod in the diet. Size distributions of beaks and otoliths are presented. A number of rarely caught species of cephalopod are important in the diet. No difference was found in diet according to the size or between male and female Prionace glauca. Comparisons with swordfish and sperm whale diets from the same region clearly suggest selection in their predation

A dieta do espadarte (Xiphias gladius) em águas Açorianas

Foram recolhidos um total de 132 estômagos de espadarte durante os anos de 1992/93 em indivíduos capturados em palangre derivante perto do arquipélago dos Açores. Os conteúdos foram completamente separados em componentes que incluíam: todos os estados de digestão de peixes e cefalópodes, desde peixes completos até fragmentos de músculo, ossos e otólitos e bicos de cefalópodes. Os peixes e os ossos maiores, que podem ser identificados, pertenciam todos a Capros aper, Lepidopus caudatus, Pagellus bogaraveo, mictofideos e, o peixe que servia de isco, Trachurus picturatus. Músculo das lulas Todarodes sagittatus, Pholidoteuthis boschmai e a lula que servia de isco Illex sp. também foi encontrada. 1249 otólitos e 120 bicos (inferiores) de cefalópodes foram identificados até ao género ou espécie. Encontrou-se uma média de 3.1 espécies e 18 animais representados em cada estômago. 98.4% dos estômagos apresentavam restos de peixes que contribuíam com 93.4% dos animais na dieta. Encontraram-se cefalópodes em 37.4% dos estômagos que contribuíram com 5.8% dos animais. Estimou-se que os pesos dos cefalópodes e peixes contribuíam respectivamente com 50.5% e 49.5% dos conteúdos estomacais. Os constituintes mais importantes da dieta, determinados por depleção de % peso estimado são Ommastrephes bartrami (24.4%), Lepidopus caudatus (17.4%), Pholi-doteuthis boschmai (15.9%), Capros aper (14.9%), Beryx spp. (5.4%), Micromesistius poutassou Onychoteuthis sp. (3.9%), Moroteuthis sp. (2.7%) e Pagellus bogoraveo (2.2%). Ao todo, há mais do que 18 espécies de peixe e 22 de cefalópodes na dieta. Apresentam-se as distribuições por tamanho de otólitos e bicos. Há espécies bentónicas e mesopelágicas de águas oceânicas, costeiras e profundas. Aparecem, na dieta, algumas espécies raras e não registadas para os Açores. As dietas não variam de acordo com a dimensão do espadarte amostrado ou entre sexos. Cálculos preliminares sobre a biomassa mínima consumida pelo espadarte dos Açores apontam para um número entre 7280 a 8680 t por ano, sendo aproximadamente metade peixe e metade cefalópodes.ABSTRACT: A total of 132 stomachs were collected in 1992-93 from swordfish caught on drifting longlines near the Azores. Contents were sorted completely into components which comprised all stages of digested fish and cephalopods from complete fish to fragments of muscle, bones, otoliths and beaks of cephalopods. Fish and larger bones which could be identified all belonged to Capros aper. Lepidopus caudatus, Pagellus bogaraveo, myctophids, and the fish used as bait, Trachurus picturatus. Flesh of the squids Todarodes sagittatus, Pholidoteuthis boschmai and the squid used as bait Illex sp. was also present. 1249 otoliths and 120 cephalopod lower beaks were identified to genus or species. There was a mean of 3.1 species and 18 animals represented in each stomach. Fish remains occurred in 98.4% of the stomachs and contributed 93.4% of animals in the diet. Cephalopod remains occurred in 37.4% and contributed 5.8% of animals. Estimates of the weights of fish and cephalopods show that cephalopods provide 50.5% and fish species 49.5% of the stomach contents. The most important constituents of the diet by decreasing % estimated weight are Ommastrephes bartrami (24.4%), Lepidopus caudatus (17.4%), Pholidoteuthis boschmai (15.9%), Capros aper (14.9%), Beryx spp. (5.4%), Micromesistius poutassou (4.3%), Onychoteuthis sp. (3.9%), Moroteuthis sp. (2.7%) and Pagellus bogaraveo (2.2%). In all, there are more than 18 species of fish and 22 species of cephalopod in the diet. Size distributions of otoliths and beaks are presented. The species include bottom and midwater forms from both oceanic and near island water and depths. A number of rare species of cephalopods and species not recorded for the Azores are in the diet. Diet does not differ according to the size of swordfish sampled or between female and male swordfish. Preliminary calculations were made on the minimum biomass eaten by the swordfish off the Azores as 7280 - 8680 t per year, approximately half fish and half cephalopods

Formation, stability and antioxidant activity of food-grade multilayer emulsions containing resveratrol

Interfacial deposition of biopolymer layers on oil droplets may be a suitable strategy for increasing the emulsion stability and protection of functional ingredients. Resveratrol is a naturally occurring phenolic compound with numerous health-promoting properties, but its usage is still restricted due to its poor water solubility and high chemical instability. The aim of this study was to formulate single-layer (lactoferrin) and multilayer (lactoferrin/alginate and lactoferrin/alginate/-poly-l-lysine) emulsions containing resveratrol and to study the emulsions stability and antioxidant activity during storage. All primary (single-layer) emulsions had average droplet diameters below 300 nm and -potentials strongly positive, allowing the electrostatic deposition of another layer of anionic biopolymer, such as alginate. Secondary (multilayer) emulsions were highly unstable at low alginate concentrations, which was attributed to the bridging flocculation. At higher alginate concentrations, secondary emulsions were rather stable. Tertiary emulsions containing either low or high -poly-l-lysine concentrations presented flocculation, but formulations with 0.0036% (w/w) were fairly stable. The antioxidant activity of all resveratrol-loaded emulsions did not significantly change during storage, whereas it decreased in non-encapsulated resveratrol oil from the third week onwards. This study provides useful information for the design of delivery systems for resveratrol with relevance in food applications.This research was supported by the Ministerio de Ciencia e Innovación (Spain) throughout the projects AGL2009-11475 and ALG2012-35635, and 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), Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124- FEDER-027462) and FCT Strategic Project of UID/BIO/04469/2013 unit. The authors also thank the Project “BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, REF. NORTE-07-0124-FEDER-000028” Co-funded by the Programa Operacional Regional do Norte (ON.2 e O Novo Norte), QREN, FEDER. The author A. Acevedo-Fani thanks the University of Lleida for the pre-doctoral grant. The author H. D. Silva, (SFRH/BD/81288/2011) is the recipient of a fellowship from the Fundação para a Ciência e Tecnologia (FCT, Portugal). The authors would like to acknowledge to Rui Fernandes from IBMC, University of Porto, for assistance in taking the TEM microphotographs.info:eu-repo/semantics/publishedVersio

Unravelling the behaviour of curcumin nanoemulsions during in vitro digestion: effect of the surface charge

Oil-in-water nanoemulsions containing curcumin were prepared through high-pressure homogenization using corn oil and three different emulsifiers: Tween 20 (non-ionic), Sodium Dodecyl Sulphate (SDS, anionic) and DodecylTrimethylAmmonium Bromide (DTAB, cationic). A human gastric simulator was used as the in vitro digestion model (in which the stomach, duodenum, jejunum and ileum steps were performed) to evaluate the impact of surface charge on the digestion of the curcumin nanoemulsions. This model allowed the simulation of continuous peristaltic movements and consequently enabled a more mechanically realistic simulation of the dynamic digestion process than simple stirred vessel models. The emulsifier charge had a significant effect on the droplet size, particle electric charge and microstructure of curcumin nanoemulsions during the simulated digestion, which consequently influenced the free fatty acid release and curcumin bioavailability. The results showed the positively charged DTAB-stabilized emulsions to be the least stable during the digestion process, exhibiting the largest increase in droplet size and eventual phase separation. This also contributed to the low bioavailability of curcumin. Conversely, emulsions stabilized with Tween 20 showed retention of emulsion structure (high surface area) and greater free fatty acid production, which could explain the increased curcumin bioavailability. The emulsifier charge influenced the lipid digestion process and the bioavailability of the bioactive compound incorporated, probably by altering the ability of bile salts and digestive enzymes to adsorb onto the emulsion surfaces, thus altering the droplet size (and consequently the surface area) due to droplet breakup or coalescence within the digestive tract. The results of this work also highlighted the importance of subjecting the emulsions to a simulated gastric environment, since changes in pH, ionic strength, gastric enzyme activity and shear will impact the emulsion properties in the small-intestine. This manuscript has provided important insights into the effect of emulsifier charge on the behaviour of nanoemulsions during in vitro digestion, which is important to determine their functional performance, aiming at the optimization of nanoemulsion-based delivery systems to protect and release bioactive lipophilic compounds.Ana C. Pinheiro and Helder Silva gratefully acknowledge the Fundacao para a Ciencia e Tecnologia (FCT, Portugal) for their fellowships (SFRH/BD/48120/2008 and SFRH/BD/81288/2011 respectively). The author Ana C. Pinheiro would also like to acknowledge the European Union, through Cost Action FA1001 and the author Manuel A. Coimbra gratefully acknowledges QOPNA (project PEst-C/QUI/UI0062/2011)

Development and characterization of lipid-based nanosystems: effect of interfacial composition on nanoemulsion behavior

Nanoemulsions were successfully developed through high-pressure homogenization. The layer-by-layer electrostatic technique was used for the subsequent deposition of a chitosan and alginate polyelectrolyte layers, thus leading to the development of a multilayer nanoemulsion. The effect of polyelectrolytes concentration in the development of multilayer nanoemulsions was evaluated in terms of hydrodynamic diameter (Hd), polydispersity index (PdI), zeta potential (Zp), and curcumin encapsulation efficiency. The interactions between polyelectrolytes and nanoemulsion were further analyzed using Fourier transform infrared (FTIR) spectroscopy and quartz crystal microbalance (QCM), while curcumin degradation was determined through the evaluation of the antioxidant capacity of the nanosystems. Results showed an encapsulation efficiency of 99.8 ± 0.8% and a loading capacity of 0.53 ± 0.03% (w/w). The presence of the multilayers leads to an increase of the Hd of the nanosystems, from 80.0 ± 0.9 nm (nanoemulsion) to 130.1 ± 1.5 nm (multilayer nanoemulsion). Release profiles were evaluated at different conditions, fitting a linear superposition model to experimental data suggests an anomalous behavior, being the relaxation of the surfactant and polyelectrolytes the rate-determining phenomena in curcumin release. The developed nanosystems showed great potential for the incorporation of lipophilic bioactive compounds, in view of their application in food and pharmaceutical products.The authors Hélder D. Silva and Ana C. Pinheiro(SFRH/BD/81288/2011, SFRH/BPD/101181/2014, respectively) are therecipients of a fellowship from the Fundação para a Ciência e Tecnologia(FCT, Portugal). The authors would like to acknowledge Rui Fernandesfrom IBMC, University of Porto, for assistance in taking the TEM pic-tures and Estefanía López Silva, from CACTI, University of Vigo forassistance in the FTIR analysis. The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the project“BioInd–Biotechnology and Bioengineering for improved Industrial and Agro-Food processes,”REF.NORTE-07-0124- FEDER-000028, co-fundedby the Programa Operacional Regional do Norte (ON.2–O NovoNorte), QREN, FEDER. We also thank the European Commission:BIOCAPS (316265, FP7/REGPOT-2012-2013.1). This work was sup-ported by the“CARINA”project for the safeness, sustainability, andcompetitiveness of agro-food productions of Campania Region. The sup-port of EU Cost Action FA1001 is gratefully acknowledged. The authorsalso acknowledge Stepan for providing the Neobee 1053 oil.info:eu-repo/semantics/publishedVersio

Polycomb group (PcG) proteins prevent the assembly of abnormal synaptonemal complex structures during meiosis

Copyright © 2022 the Author(s). Published by PNAS. This article is distributed under Creative Commons Attribution-NonCommercial-NoDerivatives License 4.0 (CC BY-NC-ND).The synaptonemal complex (SC) is a proteinaceous scaffold that is assembled between paired homologous chromosomes during the onset of meiosis. Timely expression of SC coding genes is essential for SC assembly and successful meiosis. However, SC components have an intrinsic tendency to self-organize into abnormal repetitive structures, which are not assembled between the paired homologs and whose formation is potentially deleterious for meiosis and gametogenesis. This creates an interesting conundrum, where SC genes need to be robustly expressed during meiosis, but their expression must be carefully regulated to prevent the formation of anomalous SC structures. In this manuscript, we show that the Polycomb group protein Sfmbt, the Drosophila ortholog of human MBTD1 and L3MBTL2, is required to avoid excessive expression of SC genes during prophase I. Although SC assembly is normal after Sfmbt depletion, SC disassembly is abnormal with the formation of multiple synaptonemal complexes (polycomplexes) within the oocyte. Overexpression of the SC gene corona and depletion of other Polycomb group proteins are similarly associated with polycomplex formation during SC disassembly. These polycomplexes are highly dynamic and have a well-defined periodic structure. Further confirming the importance of Sfmbt, germ line depletion of this protein is associated with significant metaphase I defects and a reduction in female fertility. Since transcription of SC genes mostly occurs during early prophase I, our results suggest a role of Sfmbt and other Polycomb group proteins in downregulating the expression of these and other early prophase I genes during later stages of meiosis.R.G.M. is supported by Portuguese national funding through Fundação para a Ciência e a Tecnologia (FCT grant refs. PTDC/BIA-BID/28441/2017 and PTDC/BIA-BID/1606/2020). B.M. and R.D.S. are both supported by Portuguese national funding through Fundação para a Ciência e a Tecnologia, respectively, PD/BD/128342/2017 (within the scope of the ProRegeM PhD program; PD/00117/2012, CRM:0027030) and DL 57/2016/CP1361/CT0019. The Light Microscopy Unit of ABC-RI was partially supported by Portuguese national funding (FCT: PPBI-POCI-01-0145-FEDER-022122). This work was developed with the support of the research infrastructure Congento (project LISBOA-01-0145-FEDER-022170). The Transgenic RNAi Project (TRiP) collection at Harvard Medical School was supported by NIH/NIGMS R01-GM084947.info:eu-repo/semantics/publishedVersio