Papers by Edwin Elard Garcia Rojas
Food Biophysics
The present work aimed to study the influence of the pH and protein ratio on the formation of com... more The present work aimed to study the influence of the pH and protein ratio on the formation of complex coacervates of carboxymethylcellulose (CMC) and whey protein isolated nanoparticles (WPIN). These biopolymers and transglutaminase, as a cross-linking agent, were used to encapsulate sacha inchi oil (SIO) containing β-carotene (β-C). The stability of β-C from SIO microcapsules (β-SIO microcapsules) was evaluated under in vitro digestion using an INFOGEST 2.0 in vitro digestion protocol. The release of β-C in a simulated food model was studied, and mathematical models were used to determine the mechanism. A ratio of 1:6 (CMC/WPIN) at pH 3.5 was used for the formation of the complex. Chemical and morphological analyses suggested that SIO was microencapsulated and that a high encapsulation efficiency was obtained. The β-C from β-SIO microcapsules was preserved in vegetable oil (food model), and Fickian diffusion occurred. The β-C from β-SIO microcapsules was preserved under oral and gastric conditions, and higher release occurred during intestinal digestion when samples were subjected to in vitro digestion simulation. After in vitro digestion, the β-C from β-SIO microcapsules presented higher stability (83.37%) and acceptable bioaccessibility (31.16%). There are few studies in the literature of encapsulated SIO using the CMC/WPIN complex or studies of the release of β-carotene from SIO during in vitro digestion and in food simulants. The knowledge obtained in this study will facilitate the use and applications of β-C-loaded microcapsule delivery systems.
Italian Journal of Food Science, 2016
This work aimed to evaluate the antimicrobial effectiveness of a biodegradable composite, cellulo... more This work aimed to evaluate the antimicrobial effectiveness of a biodegradable composite, cellulose acetate film with the incorporation of various combinations of cinnamon, oregano and sweet fennel essential oils (EOs) against Escherichia coli, Staphylococcus aureus and Penicillium spp. Moreover, thickness, the mechanical and water vapor barrier properties of these films were evaluated. The films with the incorporation of pure oregano EO and the combination oregano + cinnamon EOs presented the best results against all microorganisms tested. The water vapor transmission rate of the film was reduced with the addition of the EOs and the thickness of the film increased. The EO increased the flexibility of the films, and the film with pure oregano EO was the most resistant, showed 30,9 N of puncture strength. The results suggest that the EOs incorporated as natural antimicrobial agents can potentially be used in food packaging, reducing the risk of microbial contamination of food.
Journal of Food Science and Technology, 2020
The influence of the concentration (5-20 mg/m L) of different cosolutes (sucrose and NaCl) on the... more The influence of the concentration (5-20 mg/m L) of different cosolutes (sucrose and NaCl) on the rheological and thermal properties of concentrated Tara gum (TG) solutions (1.5-2.5% w/v) was investigated. Furthermore, the structural properties of the TG, TG-sucrose and TG-NaCl solutions were studied. The TG, TG-sucrose and TG-NaCl solutions exhibited a pseudoplastic and typical viscoelastic behavior of an entangled network structure. An increase in the TG concentration increased the pseudoplasticity and the elasticity of the solutions, while the incorporation of NaCl reduced these properties. Sucrose had little influence on the rheological properties of the TG solutions. The texture profile and the water holding capacity of the TG solutions were significantly influenced by the concentration of the TG and did not change with the addition of the cosolutes. The thermal stability of the TG solutions was reduced by NaCl and was not altered by sucrose. The microstructures of the TG solutions was significantly affected by NaCl, supporting the results obtained from rheological and thermal analyses. The results of this study may be useful for the formulation and processing of foods containing TG.
Brazilian Journal of Food Technology, 2021
The comparative study regarding complexes coacervated between Bovine Serum Albumin (BSA) and diff... more The comparative study regarding complexes coacervated between Bovine Serum Albumin (BSA) and different polysaccharides, Pectin (PEC) and Gum Acacia (GA), was carried out by evaluating the influence of different ratios (protein:polysaccharide) and sodium chloride (NaCl) concentrations on turbidity and zeta potential. The BSA:PEC complexes were formed in a 10:1 ratio whereas BSA:GA at 3:1. The complexation pH showed different behavior, BSA: PEC complexes exhibited maximum turbidity in a wide pH range (4.9 to 1.5), while BSA: GA had maximum turbidity at pH 3.5. The increase in the concentration of NaCl negatively influenced the complexation. The NaCl concentration of 0.40 mol L-1 suppressed the interaction in BSA:PEC (10:1) and reduced the range formation of BSA:GA (3:1). The Fourier Transform Infrared (FTIR) demonstrated the participation not only of electrostatic interactions, but also of hydrogen bonds in the complexation. This initial study elucidated fundamental aspects about the ...
Food Hydrocolloids, 2021
Abstract Galactomannans are nonionic polysaccharides structurally composed of residues of mannose... more Abstract Galactomannans are nonionic polysaccharides structurally composed of residues of mannose and galactose, and they are mainly obtained from the seed endosperm of leguminous plants. In specific cases, galactomannans can be subjected to chemical, physical or biological modifications in order to reduce their thickening ability, increase solubility and insert charged groups. Among galactomannans, guar gum, locust bean gum, fenugreek gum and tara gum in their native or modified form are used as ingredients in food products but also as biomaterials because of their potential use as carriers of bioactive compounds. Different methods have been used to create delivery systems (spray drying, hydrogel, emulsion and coacervation) that contain native or modified galactomannans associated with other biopolymers that encapsulate different bioactive agents, such as dyes, vitamins, essential oils, peptides and enzymes. This minireview aims to present the main galactomannans and their modifications used in the encapsulation of bioactive compounds applied in food.
Food Hydrocolloids, 2021
In this study, a controlled release system of coacervated complexes consisting of lactoferrin (LF... more In this study, a controlled release system of coacervated complexes consisting of lactoferrin (LF) and carboxymethyl tara gum (CMTG) was developed. Zeta potential and turbidity measurements were employed to optimize pH and the LF:CMTG ratio, and the results showed that pH 4.0 and a 5:1 ratio (LF:CMTG) were ideal for complex formation. These conditions promoted the encapsulation of vitamin D 3 , and the encapsulation efficiency (EE) was determined to be a function of the total concentration of biopolymers (TC%) and the core-to-wall ratio. The results showed that the highest EE (81%) was achieved for a TC of 1% and a ratio of 1:3. The particles had a spherical shape and an average size of 1.2 μm, which was influenced by the TC%. The thermal stability of the vitamin increased after microencapsulation, and Fourier transform infrared spectroscopy (FTIR) demonstrated the presence of biopolymers and vitamins in the microcapsules. The results of the in vitro simulation showed that the microcapsules enabled the vitamin to be released in the intestine with 35% bioaccessibility. Encapsulation of lipophilic bioactive compounds, such as vitamin D 3 , was achieved through complexes formed between LF and CMTG, which improved the stability and promoted the controlled release of the vitamin during gastrointestinal simulation in vitro.
Food Chemistry, 2021
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Polímeros, 2019
Due to their aqueous nature and biocompatibility, water/water emulsions are particularly advantag... more Due to their aqueous nature and biocompatibility, water/water emulsions are particularly advantageous in the production of low calorie functional food and bioactive carrier microparticles. The aim of this study was to investigate the stability of water/water emulsions formed by gelatin and carboxymethycelullose through the Pickering effect, by addition of whey protein particles. The effect of phase composition and pH on emulsion stability over 3 days of storage was studied and the emulsion properties were characterized. Finally, the effect of the addition of different concentrations of whey protein particles on the emulsion stability was investigated. The added protein particles contributed to reduce the rate of phase separation and higher protein concentration showed this effect more clearly. The time of complete phase separation increased 12 h after addition of 15% (w/w) protein. Emulsions at pH 5.5 with protein particles, however, showed lower stability than those at pH 7.5 without particles.
International Journal of Biological Macromolecules, 2020
This study evaluated the most appropriate conditions (pH and biopolymers ratio) for the formation... more This study evaluated the most appropriate conditions (pH and biopolymers ratio) for the formation of the complex between β-lactoglobulin (β-lg) and sodium alginate (NaAlg). Furthermore, we microencapsulated black pepper essential oil (EO) using these biopolymers and transglutaminase as a cross-linking agent, and stability during in vitro digestion and its release in food models were studied. A ratio of 17:1 (β-lg/NaAlg) at a pH of 4.5 was the optimal condition for the formation of the complex. The encapsulation efficiency (85.01% ± 0.26) and chemical and morphological characteristics suggested that black pepper EO was microencapsulated using polymers and cross-linking agent naturals. The particle size demonstrated that the capsules produced were on micro scale. The black pepper EO microcapsules lost lower release in water, and the Rigger-Peppas model indicated that the Fickian diffusion mechanism occurred. The microcapsules demonstrated a low release of black pepper EO during oral and gastric digestion and a higher release in intestinal digestion. The black pepper EO after digestion presented high stability (84.8% ± 0.07), and bioaccessibility (31.16% ± 0.3). The results suggest that the black pepper EO was microencapsulated and, preserved in aqueous food model and during oral and gastric conditions tested in vitro.
Brazilian Journal of Food Research, 2018
Polysaccharides are widely used as thickening, stabilizing, and gelling agents for the control of... more Polysaccharides are widely used as thickening, stabilizing, and gelling agents for the control of the texture, flavor, microstructure, and shelf-life of foods. This work contributes to the study of the physical properties and rheological behavior of binary and ternary solutions of carrageenan and acacia gum. Experiments were performed to determine properties such as density, refractive index, and viscosity. The results showed that those properties studied increased with increasing biopolymer concentration and decreased with increasing temperature. Experimental data were modeled to describe the combined effects of temperature and biopolymer concentration on the density, refractive index, and dynamic viscosity of these solutions. The properties were measured in the temperature range from 298.15 to 308.15 K. Suitable polynomial functions were successfully fitted to the experimental data. Classical rheological models (Bingham, power law, Casson, and Herschel-Bulkley) were tested for binary and ternary aqueous solutions containing carrageenan. Pseudoplastic behavior was observed, and the solutions were accurately modeled through a power-law model.
Food Chemistry, 2020
The terpenes presented in black pepper essential oil (EO) are volatile and their properties can b... more The terpenes presented in black pepper essential oil (EO) are volatile and their properties can be reduced in certain conditions. The encapsulation can protect the EO and preserve their terpenes. Complex coacervation was chosen because of several advantages. This study aimed to analyze the composition of black pepper EO, determining the most appropriate conditions for the formation of the complex between gelatin and sodium alginate. Further, we also encapsulated the black pepper EO. The main terpene identified in black pepper EO was β-caryophyllene. The ratio of 6:1 (gelatin/sodium alginate) at pH 4.0 was the ideal condition. The encapsulation efficiency varied from 49.13 to 82.36%, and the chemical composition of the encapsulated EO was identified by Gas Chromatography (GC). GC analysis indicated good core protection with the materials used. These biopolymers can serve as a potential delivery system for black pepper EO.
Journal of Thermal Analysis and Calorimetry, 2017
The oxidative stability of edible oils is an important feature to know due the undesirable change... more The oxidative stability of edible oils is an important feature to know due the undesirable changes that can occur in the storage. In this way, the oxidative induction time (OIT) value is an indicative to prevent this effect. The objectives of this study were to evaluate the omega-3 content and kinetic parameters of Sacha Inchi oil (SIO) and capsules that are formed with biopolymers, in addition, there were analyzed with differential scanning calorimetry (DSC) and proton nuclear magnetic resonance (1 H NMR). The SIO and capsules, formed using an emulsion, were analyzed with DSC in an oxygen atmosphere to determine the OIT value in isothermal conditions at 100, 120 and 150°C. The kinetic parameters (activation energy, preexponential factor and z value) of SIO were obtained, and the stability time was predicted at different temperatures. The 1 H NMR spectra enabled us to assess the identification and percentage relative before and after the isothermal DSC oxidation of omega-3 concentration and formation of their oxidized compounds. (E-E)-2,4-Alkadienals were the primary oxidized compound and is strongly correlated with the decrease in omega-3 content. Isothermal DSC is a useful to determine the OIT (min) and kinetic parameters to predict the stability oxidation in different edible oils and thus prevent the inadequate consumption of edible oils oxidized.
Comprehensive Reviews in Food Science and Food Safety, 2018
Whey proteins are obtained from dairy industry waste. Studies involving the analysis of the bioac... more Whey proteins are obtained from dairy industry waste. Studies involving the analysis of the bioactive compounds in whey show health benefits, as it is an excellent source of indispensable amino acids. Milk whey contains principally β‐lactoglobulin, α‐lactoglobulin, bovine serum albumin, and lactoferrin, proteins with innumerable functional and technological properties. One application of these proteins in food is the formation of interpolymer complexes, along with other proteins or anionic polysaccharides. The formation of complexes occurs mainly through electrostatic interactions between a negatively charged biopolymer and a positively charged biopolymer. This formation is influenced by factors such as pH, ionic strength, and biopolymer ratio. Because they do not use high temperatures and chemical reagents and have additional nutritional and functional value, these complexes have been used as encapsulating agents for bioactive ingredients. Recent studies on their training and appli...
Polímeros, 2018
Proteins are frequently used as emulsifiers and stabilizers. In this work, two proteins with diff... more Proteins are frequently used as emulsifiers and stabilizers. In this work, two proteins with different isoelectric points were used: lactoferrin and ovalbumin. Solutions containing different proteins ratios, with different pH values, were stored for 7 days at 25 °C to analyze the system stability. Systems containing 3% w/v lactoferrin remained stable at all pH values studied, while systems containing 1% w/v ovalbumin remained stable only at a high pH value (8.0). Emulsions containing a mixture of proteins remained stable at a pH between the isoelectric points of the two proteins, which was attributed to an electrostatic bond because of the opposite charges of proteins at this pH. During the analysis of rheological properties, it was possible to observe a non-Newtonian behavior of the emulsions, using the models of Carreau and Cross to describe the pseudoplastic behavior of suspensions. This study provides important information for the use of functional ingredients.
International Journal of Biological Macromolecules, 2018
In the present work, we aimed to explore the molecular binding between alginate and β-galactosida... more In the present work, we aimed to explore the molecular binding between alginate and β-galactosidase, as well as the effect of this interaction on the activity retention, thermal stability, and kinetic properties of the enzyme. The impact of pH and enzyme/alginate ratio on physicochemical properties (turbidity, morphology, particle size distribution, ζ-potential, FTIR, and isothermal titration calorimetry) was also evaluated. The ratio of biopolymers and pH of the system directly affected the critical pH of complex formation; however, a low alginate concentration (0.1 wt%) could achieve an electrical charge equivalence at pH 3.4 with 93.72% of yield. The binding between β-galactosidase and alginate was an equilibrium between enthalpic and entropic contributions, which promoted changes in the structure of the enzyme. Nevertheless, this conformational modification was reversible after the dissociation of the complex, which allowed the enzyme to regain its activity. These findings will likely broaden functional applications of enzyme immobilization.
Food Hydrocolloids, 2018
The formation of a heteroprotein complex obtained by the interaction of bovine serum albumin (BSA... more The formation of a heteroprotein complex obtained by the interaction of bovine serum albumin (BSA) and lysozyme (Lys) was investigated by pH variation using turbidimetric analysis and zeta potential (z) at different protein ratios and NaCl concentrations. The complexes were formed in a pH range between 8.0 and 11.0, with the ratio r ¼ 0.5 at pH 9.0 presenting the highest complexation. The addition of NaCl decreased the interaction at concentrations of 10 mM. The complex formation occurred between the isoelectric points (pI) of the proteins, close to a balance of charges, mainly by electrostatic interactions with some participation of hydrogen bonds. Differential scanning calorimetry suggested that the interaction gave rise to a new biopolymer due to the formation of a single denaturation point at 67 C. The structures formed had an average size of~1.7 mm, well above that of the isolated proteins, and microscopic analysis revealed that the complexes had a globular structure. BSA/Lys complexes may be a potential bioactive encapsulating agent and may be used as a food ingredient.
International Journal of Biological Macromolecules, 2017
The formation of heteroprotein coacervates obtained by the interaction of ovalbumin (Ova) and lys... more The formation of heteroprotein coacervates obtained by the interaction of ovalbumin (Ova) and lysozyme (Lys) was investigated using turbidimetric analysis and the zeta potential at different protein ratios, pH values and concentrations of NaCl. The complexes were formed over a wide pH range with a 1:1 (Ova:Lys) ratio and the highest turbidity was observed at pH 7.5, which optimal biopolymer interactions occurring. The addition of NaCl disfavored formation, even at low concentrations, and suppressed it at 300 mM. The complex coacervate formation occurred in the region between the isoelectric points (pI) of the proteins, predominantly by electrostatic interactions but with participation of hydrogen bonds. The structures formed had an average size of ∼2 m, which was well above the isolated proteins, and microscopic analysis revealed that the complexes had a globular structure. The interaction was exothermic and spontaneous with a favorable entropic and unfavorable entropic contribution during interaction.
Ciência Rural, 2016
ABSTRACT: The interactions between biological macromolecules have been important for biotechnolog... more ABSTRACT: The interactions between biological macromolecules have been important for biotechnology, but further understanding is needed to maximize the utility of these interactions. Calorimetric techniques provide information regarding these interactions through the thermal energy that is produced or consumed during interactions. Notable techniques include differential scanning calorimetry, which generates a thermodynamic profile from temperature scanning, and isothermal titration calorimetry that provide the thermodynamic parameters directly related to the interaction. This review described how calorimetric techniques can be used to study interactions between proteins and polysaccharides, and provided valuable insight into the thermodynamics of their interaction.
Food Chemistry, 2016
In this study, interactions between polypeptide-leucine (0.2% w/w) and gum arabic (0.03, 0.06, 0.... more In this study, interactions between polypeptide-leucine (0.2% w/w) and gum arabic (0.03, 0.06, 0.09, 0.12, and 0.15% w/w) were examined at concentrations of NaCl (0, 0.01, 0.25, 0.3, 0.5mol/l) and at different pH values (from 1.0 to 12.0). Formation of insoluble complex coacervates was highest at pH 4.0. At pH 2.0, which is the pKa of the gum Arabic, the dissociation of precipitate occurred. The pHØ2 positively shifted with the addition of higher concentrations of salt. Samples containing 0.2% PL and 0.03% GA and no salt had higher turbidity and increased formation of precipitates showing greater turbidity and particle sizes. The Fourier transform infrared spectroscopy confirms the complex coacervate formation of leucine and gum arabic, and rheological measurements suggest the elastic behavior of 0.2% PL and 0.03% GA complex. Overall, the study suggests that complex coacervates of PLs could be one feasible ways of incorporating amino acids in food products.
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Papers by Edwin Elard Garcia Rojas