Tailoring swelling of alginate-gelatin hydrogel microspheres by crosslinking with calcium chloride combined with transglutaminase

lginate-based hydrogels can find uses in a wide range of applications, including in the encapsulation field. This type of hydrogels is usually ionically crosslinked using calcium sources giving rise to products with limited internal crosslinking. In this work, it is hypothesized that the combination of alginate crosslinked by calcium chloride (external crosslinking; ionic mechanism) with gelatin crosslinked by transglutaminase (internal crosslinking; enzymatic induced mechanism) can be used to tailor the swelling behavior of alginate-based hydrogel microspheres. A systematic study was conducted by covering process variables such as gelatin content, TGase concentration, and CaCl2 contact time, added by statistic tools as central composite rotatable design (CCRD), principal component analysis (PCA) and multiobjective optimization, to map their effect on the resulting water content after production (expressed as swelling ratio), and swelling properties at pH 3 and 7. Among the studied variables, particle's swelling was mostly affected by the gelatin content and transglutaminase concentration.This work was financially supported by Associate Laboratory LSRELCM (UID/EQU/50020/2019) funded by national funds through FCT/ MCTES (PIDDAC), and Foundation for Science and Technology (FCT, Portugal) and by CIMO (UID/AGR/00690/2019) trough FEDER under Program PT2020. The authors are grateful to CAPES, CNPq and Fundação Araucária for the support and also to Ajinomoto Foods Europe S.A.S. (France) for kindly provide the transglutaminase sample used in this work. I.P. Fernandes thanks the national funding by FCT, P.I., through the institutional scientific employment program-contract for her contract.info:eu-repo/semantics/publishedVersio

Bioactive evaluation and application of different formulations of the natural colorant curcumin (E100) in a hydrophilic matrix (yogurt)

Curcumin (E100) is a natural colorant that, besides conferring color, has bioactivity, serving as an alternative to some artificial colorants. As a hydrophobic colorant, its modification/compatibilization with the aqueous medium is required to improve stability and enable its application in hydrophilic food matrices. Herein, different formulations of curcumin (curcumin powder: PC, water-dispersible curcumin: DC: and nanoencapsulated curcumin: NC) were evaluated as yogurt colorants. PC showed the strongest bioactivity in all assays (EC50 values: 63±2 to 7.9±0.1 μg.mL-1; GI50 values: 48±1 to 17±1 μg.mL-1 and MIC values: 0.0625 to 0.5 mg.mL-1), which might indicate that DC and NC reduce the short-term accessibility to curcumin. The tested curcumin formulations produced yogurts with different appearance, specifically associated with their color parameters, besides presenting slight changes in nutritional composition and free sugars and fatty acids profiles. The water compatible formulations (DC and NC) showed advantages over hydrophobic (PC) having a wider industrial utilization.info:eu-repo/semantics/publishedVersio

Lipid composition optimization in spray congealing technique and testing with curcumin-loaded microparticles

Spray-congealing, a technique based on the fast solidification of sprayed molten lipids, is considered a novel strategy to encapsulate natural products. Among others, it is a safe, low cost, fast and reproducible technique, with rising interest for several applications (e.g. food applications). One of the key parameters for the application of this technique is the lipid solidification temperature, which can be modulated by optimizing the lipid composition. In this work, three lipid components (beeswax, carnauba wax, and medium-chain triglycerides (Miglyol 812)) were selected, and the mixture composition modelled using a simplex-centroid experimental design. Three different lipid compositions were chosen to validate the proposed model, then tested in the preparation of curcumin-loaded microparticles (1.5%, w/w). The produced microparticles were analysed in terms of colour, morphology, particle size, encapsulation efficiency and load, physicochemical, crystalline, and thermal properties. Results evidenced that microparticle's properties, including encapsulation efficiency, vary according to the used lipid mixture, supporting their tailoring role. This fact brings advantages in the design of microencapsulation systems based on spray congealing processes, broadening their applicability. Moreover, lipid composition optimisation was proved to be an important tool to precede the development of spray-congealing applications.info:eu-repo/semantics/publishedVersio

TPCS/PBAT blown extruded films added with curcumin as a technological approach for active packaging materials

The development of active packaging is a relevant topic demanding the development of films with diverse properties to preserve specific foodstuff. The objective of this work was to obtain extruded TPCS/PBAT films containing curcumin and evaluate it as an active antimicrobial and antioxidant packaging to protect chia oil from oxidative degradation. Morphology, thermal, mechanical, antimicrobial, and antioxidant evaluation of the films were conducted to determine whether the presence of curcumin affected the film’s properties. Infrared Spectroscopy indicated that curcumin addition affected the crosslinking reaction between citric acid and starch, which explains the changes in hydrophilicity and mechanical strength of the films. The incorporation of curcumin conferred antimicrobial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacteria, as well as antioxidant activity. Films were tested as chia oil packaging, being verified that they successfully prevented oil degradation under accelerated stability test (60 °C for 7 days), demonstrating the feasibility of using TPCS/PBAT biodegradable films containing curcumin to obtain active packaging materials.Authors thank to CNPq (Chamada Universal– MCTI/CNPq Nº 14/2014, Processo 447768/2014-0), CAPES (Coordenação de Pessoal de Nível Superior Master's scholarship) and Fundação Araucária (Programa Universal/Pesquisa Básica e Aplicada 24/2012, protocolo 7334133700514041013) for the finantial support. This work was financially supported by Associate Laboratory LSRE-LCM (UID/EQU/50020/2019) funded by national funds through FCT/MCTES (PIDDAC), and Foundation for Science and Technology (FCT, Portugal). CIMO (UID/AGR/00690/2019) through FEDER under Program PT2020. To the national funding by FCT, P.I., through the institutional scientific employment program-contract for I.P. Fernandes contract.info:eu-repo/semantics/publishedVersio

Formulation of mayonnaises containing PUFAs by the addition of microencapsulated chia seeds, pumpkin seeds and baru oils

There is an increasing demand for healthier foodstuff containing specific compounds such as Polyunsaturated Fatty Acids (PUFAs). In the case of PUFAs, protection against oxidative degradation is challengeable and microencapsulation emerges as an alternative. Mayonnaises containing microencapsulated oils could be a source of PUFAs. The objective was to formulate mayonnaises containing microencapsulated chia seeds oil, pumpkin seeds oil or baru oil. Micrometric particles with high encapsulation efficiency were produced and thermal analyses indicated an increased thermal stability of all oils after encapsulation. Rheology studies highlighted an increase in the mayonnaise viscosity when microparticles containing chia and pumpkin seeds oil were added. Mechanical texture was not affected by the presence of microparticles in the mayonnaise in all formulations tested. Nevertheless, samples containing microcapsules up to 5%wt were not distinguished from the base-mayonnaise in the sensorial test. Overall, enriched mayonnaises were successfully produced and encapsulation was efficient in protecting oils from oxidation.Authors thank CAPES , CNPq and Fundação Araucária for the support. The authors are grateful to the Foundation for Science and Technology ( FCT , Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2013) and L. Barros contract.info:eu-repo/semantics/publishedVersio

Poly(3-hydroxybutirate-co-3-hydroxyvalerate)-Polystyrene Hybrid Nanoparticles via Miniemulsion Polymerization

Hybrid polymer nanoparticles were obtained by miniemulsion polymerization of styrene with poly(3-hydroxybutirate-co-3-hydroxyvalerate) (PHBV). Lower polymerization rates were obtained with the gradual addition of PHBV. These results were represented by simulations using a mathematical model that takes into account grafting reactions between the growing polymeric chains and PHBV double bonds (reduced molar mass). Hybrid nanoparticles presented average diameters of up to 113 nm and grafting yield of 94.4%. The hybrid fractions obtained by Selective Soxhlet Extraction were characterized with Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimetry and Transmission Electron Microscopy. Blend nanoparticles were used to confirm the hybrid formation