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1.
Antioxidants (Basel) ; 13(9)2024 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-39334804

RESUMEN

The encapsulation of fish oil by monoaxial electrospraying using kafirin or zein proteins as hydrophobic wall materials was investigated. Kafirin resulted in spherical fish oil-loaded nanocapsules (>50% of capsules below 1 µm), whereas zein led to fish oil-loaded nanocapsules with non-spherical morphology (>80% of capsules below 1 µm). Both hydrophobic encapsulating materials interacted with fish oil, successfully entrapping the oil within the protein matrix as indicated by Fourier-transform infrared spectroscopy (FTIR) and Raman spectroscopy results. FTIR also suggested hydrogen bonding between fish oil and the proteins. Trapped radicals in the encapsulation matrix that were detected by electron paramagnetic resonance (EPR), indicated oxidation during electrospraying and storage. Results from isothermal (140 °C) differential scanning calorimetry (DSC) denoted that the encapsulation of fish oil by electrospraying using both kafirin or zein as wall materials protected fish oil from oxidation. In particular, the zein-based nanocapsules were 3.3 times more oxidatively stable than the kafirin-based nanocapsules, which correlates with the higher oil encapsulation efficiency found for zein-based capsules. Thus, this study shows that kafirin might be considered a hydrophobic wall material for the encapsulation of fish oil by electrospraying, although it prevented lipid oxidation to a lower extent when compared to zein.

2.
Food Chem ; 426: 136498, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37295051

RESUMEN

Bioinformatics tools were used to predict radical scavenging and metal chelating activities of peptides derived from abundant potato, seaweed, microbial, and spinach proteins. The antioxidant activity was evaluated in 5% oil-in-water emulsions (pH4) and best-performing peptides were tested in mayonnaise and compared with EDTA. Emulsion physical stability was intact. The peptide DDDNLVLPEVYDQD showed the highest protection against oxidation in both emulsions by retarding the formation of oxidation products and depletion of tocopherols during storage, but it was less efficient than EDTA when evaluated in mayonnaise. In low-fat emulsions, formation of hydroperoxides was reduced 4-folds after 5 days compared to control. The concentration effect of the peptide was confirmed in mayonnaise at the EDTA equimolar concentration. The second-best performing peptides were NNKWVPCLEFETEHGFVYREHH in emulsion and AGDWLIGDR in mayonnaise. In general, the peptide efficacy was higher in low-fat emulsions. Results demonstrated that peptide negative net charge was important for chelating activity.


Asunto(s)
Antioxidantes , Aceites de Pescado , Emulsiones , Ácido Edético , Agua , Oxidación-Reducción , Péptidos , Concentración de Iones de Hidrógeno
3.
Antioxidants (Basel) ; 12(3)2023 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-36979010

RESUMEN

This work studied the physical and oxidative stabilities of fish oil-in-water-in-olive oil double emulsions (O1/W/O2), where whey protein hydrolysate was used as a hydrophilic emulsifier. A 20 wt.% fish oil-in-water emulsion, stabilized with whey protein hydrolysate (oil: protein ratio of 5:2 w/w) and with a zeta potential of ~-40 mV, only slightly increased its D4,3 value during storage at 8 °C for seven days (from 0.725 to 0.897 µm), although it showed severe physical destabilization when stored at 25 °C for seven days (D4,3 value increased from 0.706 to 9.035 µm). The oxidative stability of the 20 wt.% fish oil-in-water emulsion decreased when the storage temperature increased (25 vs. 8 °C) as indicated by peroxide and p-anisidine values, both in the presence or not of prooxidants (Fe2+). Confocal microscopy images confirmed the formation of 20 wt.% fish oil-in-water-in-olive oil (ratio 25:75 w/w) using Polyglycerol polyricinoleate (PGPR, 4 wt.%). Double emulsions were fairly physically stable for 7 days (both at 25 and 8 °C) (Turbiscan stability index, TSI < 4). Moreover, double emulsions had low peroxide (<7 meq O2/kg oil) and p-anisidine (<7) values that did not increase during storage independently of the storage temperature (8 or 25 °C) and the presence or not of prooxidants (Fe2+), which denotes oxidative stability.

4.
Antioxidants (Basel) ; 12(2)2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36829825

RESUMEN

The impact of the encapsulation technology on the oxidative stability of fish-oil-loaded capsules was investigated. The capsules (ca. 13 wt% oil load) were produced via monoaxial or coaxial electrospraying and spray-drying using low molecular weight carbohydrates as encapsulating agents (e.g., glucose syrup or maltodextrin). The use of spray-drying technology resulted in larger capsules with higher encapsulation efficiency (EE > 84%), whilst the use of electrospraying produced encapsulates in the sub-micron scale with poorer retention properties (EE < 72%). The coaxially electrosprayed capsules had the lowest EE values (EE = 53-59%), resulting in the lowest oxidative stability, although the lipid oxidation was significantly reduced by increasing the content of pullulan in the shell solution. The emulsion-based encapsulates (spray-dried and monoaxially electrosprayed capsules) presented high oxidative stability during storage, as confirmed by the low concentration of selected volatiles (e.g., (E,E)-2,4-heptadienal). Nonetheless, the monoaxially electrosprayed capsules were the most oxidized after production due to the emulsification process and the longer processing time.

5.
Food Funct ; 13(24): 12510-12540, 2022 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-36420754

RESUMEN

Inflammation is the response of the immune system to harmful stimuli such as tissue injury, infection or toxic chemicals, which has the aim of eliminating irritants or pathogenic microorganisms and enhancing tissue repair. Uncontrolled long-lasting acute inflammation can gradually progress to chronic, causing a variety of chronic inflammatory diseases that are usually treated with anti-inflammatory drugs, but most of them are inadequate to control chronic responses and are also associated with adverse side effects. Thus, many efforts are being directed to develop alternative and more selective anti-inflammatory therapies from natural products. One main field of interest is the obtaining of bioactive peptides exhibiting anti-inflammatory activity from sustainable protein sources like edible insects or agroindustry and fishing by-products. This work highlighted the structure-activity relationship of anti-inflammatory peptides. Small peptides with molecular weight under 1 kDa and amino acid chain length between 2 to 20 residues are generally the most active because of the higher probability to be absorbed in the intestine and penetrate into cells when compared with the larger size peptides. The presence of hydrophobic (Val, Ile, Pro) and positively charged (His, Arg, Lys) amino acids is another common occurrence for anti-inflammatory peptides. Interestingly, a high percentage (77%) of these bioactive peptides can be found in alternative sustainable protein sources such as Tenebrio molitor or sunflower, apart from its original protein source. However, not all of these peptides with anti-inflammatory potential in vitro achieve good scores by the in silico bioactivity predictors studied. Therefore, it is essential to implement current bioinformatics tools, in order to complement in vitro experiments with prior prediction of potential bioactive peptides.


Asunto(s)
Péptidos , Hidrolisados de Proteína , Hidrolisados de Proteína/farmacología , Hidrolisados de Proteína/metabolismo , Secuencia de Aminoácidos , Péptidos/química , Aminoácidos , Antiinflamatorios/farmacología
6.
Antioxidants (Basel) ; 11(8)2022 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-36009330

RESUMEN

In this work, we evaluated the physical and oxidative stabilities of 5% w/w fish oil-in-water emulsions stabilized with 1%wt Tween20 and containing 2 mg/mL of protein hydrolysates from olive seed (OSM-H), sunflower (SFSM-H), rapeseed (RSM-H) and lupin (LUM-H) meals. To this end, the plant-based substrates were hydrolyzed at a 20% degree of hydrolysis (DH) employing a mixture 1:1 of subtilisin: trypsin. The hydrolysates were characterized in terms of molecular weight profile and in vitro antioxidant activities (i.e., DPPH scavenging and ferrous ion chelation). After incorporation of the plant protein hydrolysates as water-soluble antioxidants in the emulsions, a 14-day storage study was conducted to evaluate both the physical (i.e., ζ-potential, droplet size and emulsion stability index) and oxidative (e.g., peroxide and anisidine value) stabilities. The highest in vitro DPPH scavenging and iron (II)-chelating activities were exhibited by SFSM-H (IC50 = 0.05 ± 0.01 mg/mL) and RSM-H (IC50 = 0.41 ± 0.06 mg/mL). All the emulsions were physically stable within the storage period, with ζ-potential values below -35 mV and an average mean diameter D[4,3] of 0.411 ± 0.010 µm. Although LUM-H did not prevent lipid oxidation in emulsions, OSM-H and SFSM-H exhibited a remarkable ability to retard the formation of primary and secondary lipid oxidation products during storage when compared with the control emulsion without antioxidants. Overall, our findings show that plant-based enzymatic hydrolysates are an interesting alternative to be employed as natural antioxidants to retard lipid oxidation in food emulsions.

7.
Food Chem ; 390: 133169, 2022 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-35561508

RESUMEN

The secondary structure of whey protein concentrate hydrolysate (WPCH), used as an emulsifier in oil delivery systems, was investigated using Synchrotron Radiation Circular Dichroism (SRCD). The effect of pH on the conformation of peptides in solution and adsorbed at the oil/water interface, as well as the thermal stability of the systems was studied. Furthermore, oil-loaded microcapsules were produced by spray-drying or electrospraying to investigate the influence of encapsulating agents (glucose syrup, maltodextrin) and drying technique on the secondary structure of WPCH at the oil/water interface. Enzymatic hydrolysis resulted in peptides with a highly unordered structure (∼60% turns and unordered regions) in solution. However, WPCH adsorption onto the oil/water interface increased the α-helical content resulting in an improved thermal stability. The encapsulating agents and spray-drying process did not modify the conformation of WPCH at the oil/water interface. Nonetheless, electrospraying affected the SRCD spectra obtained for WPCH adsorbed at the oil/water interface.


Asunto(s)
Hidrolisados de Proteína , Suero Lácteo , Emulsionantes/química , Emulsiones/química , Concentración de Iones de Hidrógeno , Proteína de Suero de Leche/química
8.
Food Chem ; 392: 133257, 2022 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-35636185

RESUMEN

The influence of the emulsifier type and the encapsulating agent on the bioaccessibility of microencapsulated fish oil was investigated. Fish oil-loaded microcapsules were produced by spray-drying using carbohydrate-based encapsulating agents (glucose syrup or maltodextrin). Whey protein concentrate hydrolysate (WPCH) or Tween 20 (TW20) were used as the emulsifiers. The microcapsules were subjected to a three-phase in vitro digestion (oral, gastric, and intestinal phase) and the changes in the physicochemical properties of the samples were monitored throughout the simulated gastrointestinal tract (oil droplet size, ζ-potential, and microstructure). The lipolysis rate and extent were evaluated at the intestinal digestion phase. Contrary to the encapsulating agent, the emulsifier used in the infeed emulsion formulation significantly influenced lipid digestion. WPCH-based interfacial layer prevented oil droplets coalescence during and after processing more efficiently than TW20, which resulted in an increased specific surface area for lipases to adsorb and thus a higher bioaccessibility of the microencapsulated oil.


Asunto(s)
Emulsionantes , Aceites de Pescado , Cápsulas/química , Digestión , Emulsionantes/química , Emulsiones/química , Aceites de Pescado/química
9.
Food Chem ; 385: 132699, 2022 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-35313195

RESUMEN

In this study, we used a combination of quantitative proteomics and bioinformatic prediction for identifying novel antioxidant peptides. Thirty-five peptides from potato, seaweed, microbial, and spinach proteins were investigated. Based on high DPPH radical scavenging activity (IC50 ≤ 16 mg/mL), metal chelation activity, isoelectric point, and high relative abundance in the parent protein sources, 11 peptides were selected. Lipid oxidation retardation was evaluated in 5% fish oil-in-water emulsions stabilized with Tween 20, where emulsion physical stability was unaffected by peptide addition. The secondary structure of selected peptides was similar in the aqueous solution and emulsions, as confirmed by synchrotron radiation circular dichroism spectroscopy. The emulsions containing the selected peptides had lower levels of hydroperoxides and volatile compounds during storage compared to the control (without peptide). This study contributes to elucidating the effect of antioxidant peptides in emulsions and demonstrates the ability of quantitative proteomics and bioinformatics prediction to identify peptides with strong antioxidant properties.


Asunto(s)
Algas Marinas , Solanum tuberosum , Antioxidantes/química , Emulsiones/química , Aceites de Pescado/química , Oxidación-Reducción , Estrés Oxidativo , Péptidos/química , Algas Marinas/química , Solanum tuberosum/química , Spinacia oleracea , Agua/química
10.
Food Chem ; 362: 130217, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34098440

RESUMEN

Global focus on sustainability has accelerated research into alternative non-animal sources of food protein and functional food ingredients. Amphiphilic peptides represent a class of promising biomolecules to replace chemical emulsifiers in food emulsions. In contrast to traditional trial-and-error enzymatic hydrolysis, this study utilizes a bottom-up approach combining quantitative proteomics, bioinformatics prediction, and functional validation to identify novel emulsifier peptides from seaweed, methanotrophic bacteria, and potatoes. In vitro functional validation reveal that all protein sources contained embedded novel emulsifier peptides comparable to or better than sodium caseinate (CAS). Thus, peptides efficiently reduced oil-water interfacial tension and generated physically stable emulsions with higher net zeta potential and smaller droplet sizes than CAS. In silico structure modelling provided further insight on peptide structure and the link to emulsifying potential. This study clearly demonstrates the potential and broad applicability of the bottom-up approach for identification of abundant and potent emulsifier peptides.


Asunto(s)
Emulsionantes/química , Péptidos/química , Algas Marinas/química , Solanum tuberosum/química , Bacterias/química , Biomasa , Caseínas/química , Biología Computacional/métodos , Emulsiones/química , Ácidos Grasos Omega-3/química , Proteómica/métodos , Ralstonia/química , Agua/química
11.
Am J Emerg Med ; 48: 1-11, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33836386

RESUMEN

PURPOSE: Patients evaluated in the emergency department (ED) who have concerning symptoms suggestive of a cancer diagnosis are mostly referred to the quick diagnosis unit of our tertiary hospital. This study analyzed the impact of the Covid-19 pandemic on the volume, disease patterns, and accessibility to essential investigations of patients with suspected cancer referred by the ED to this unit. METHODS: Trends in referrals were analyzed from January 1 to July 8, 2020 and the corresponding dates of 2019. Only non-Covid-19 conditions were evaluated. Three time-based cohorts were defined: prepandemic (January 1-February 19), pandemic (February 19-April 22), and postpandemic (April 22-July 8). Along with descriptive statistics, linear regression was used to test for time trends with weekly referrals as the dependent variable. RESULTS: There were 384, 193, and 450 patients referred during the prepandemic, pandemic, and postpandemic periods, respectively. Following an increasing rate, referrals decreased to unprecedented levels in the pandemic period (average weekly slope: -2.1 cases), then increasing again until near normalization. Waiting times to most diagnostic procedures including radiology, endoscopic, nuclear medicine, and biopsy/cytology during the pandemic period were significantly delayed and time-to-diagnosis was considerably longer (19.72 ± 10.37 days vs. 8.33 ± 3.94 days in prepandemic and 13.49 ± 6.45 days in postpandemic period; P < 0.001 in both). Compared to other cohorts, pandemic cohort patients were more likely to have unintentional weight loss and fever of unknown origin as referral indications while anemia and lymphadenopathy were less common. Patients from the pandemic cohort had a significantly lower rate of malignancies and higher of benign gastrointestinal disorders (40.93% vs. 19.53% and 20.89% in prepandemic and postpandemic periods, respectively; P < 0.001 in both), most notably irritable bowel disease, and of mental and behavioral disorders (15.54% vs. 3.39% and 6.00% in prepandemic and postpandemic periods, respectively; P < 0.001 in both). CONCLUSIONS: As our hospital switched its traditional care to one focused on Covid-19 patients, recognized indicators of healthcare quality of quick diagnosis units were severely disrupted. The clinical patterns of presentation and diagnosis of the pandemic period suggested that mass media-generated mental and behavioral responses with distressing symptoms played a significant role in most of these patients.


Asunto(s)
COVID-19/prevención & control , Servicio de Urgencia en Hospital/tendencias , Accesibilidad a los Servicios de Salud/tendencias , Neoplasias/diagnóstico , Unidades de Diagnóstico Rápido/tendencias , Derivación y Consulta/tendencias , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Diagnóstico Tardío/tendencias , Diagnóstico Diferencial , Servicio de Urgencia en Hospital/organización & administración , Femenino , Estudios de Seguimiento , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Estudios Retrospectivos , España , Centros de Atención Terciaria , Adulto Joven
12.
Food Chem ; 341(Pt 2): 128141, 2021 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-33039737

RESUMEN

Enrichment of mayonnaise using delivery emulsions (DEs) containing 70% fish oil versus neat fish oil was investigated. DEs were produced with combined use of sodium caseinate, diacetyl tartaric acid esters of mono- and diglycerides (DATEM), and/or modified DATEMs with different length (C12 or C14) and covalently attached caffeic acid. Physical and oxidative stability of the mayonnaises were analyzed based on parameters including droplet size, viscosity, peroxide value, volatile compounds, and sensory properties. DEs addition to mayonnaise resulted in larger droplets and lower viscosity compared to neat fish oil. However, zeta potential was higher in mayonnaises with DEs containing DATEMs. Mayonnaise containing DATEM C14 had higher protein surface load leading to a thicker interfacial layer, lower formation of hexanal, (E)-2-hexenal, and (E)-2-heptenal as well as lower rancid odour intensity compared to mayonnaise containing DATEM and free caffeic acid, and thus benefitted from the location of the antioxidant at the interface.


Asunto(s)
Condimentos , Diglicéridos/química , Emulsiones/química , Aldehídos/química , Antioxidantes/química , Ácidos Cafeicos/química , Caseínas/química , Condimentos/análisis , Aceites de Pescado/química , Almacenamiento de Alimentos , Humanos , Odorantes , Oxidación-Reducción , Tartratos/química , Gusto , Viscosidad , Compuestos Orgánicos Volátiles/análisis , Agua/química
13.
Sci Rep ; 10(1): 21471, 2020 12 08.
Artículo en Inglés | MEDLINE | ID: mdl-33293615

RESUMEN

Dietary antioxidants are an important preservative in food and have been suggested to help in disease prevention. With consumer demands for less synthetic and safer additives in food products, the food industry is searching for antioxidants that can be marketed as natural. Peptides derived from natural proteins show promise, as they are generally regarded as safe and potentially contain other beneficial bioactivities. Antioxidative peptides are usually obtained by testing various peptides derived from hydrolysis of proteins by a selection of proteases. This slow and cumbersome trial-and-error approach to identify antioxidative peptides has increased interest in developing computational approaches for prediction of antioxidant activity and thereby reduce laboratory work. A few antioxidant predictors exist, however, no tool predicting the antioxidative properties of peptides is, to the best of our knowledge, currently available as a web-server. We here present the AnOxPePred tool and web-server ( http://services.bioinformatics.dtu.dk/service.php?AnOxPePred-1.0 ) that uses deep learning to predict the antioxidant properties of peptides. Our model was trained on a curated dataset consisting of experimentally-tested antioxidant and non-antioxidant peptides. For a variety of metrics our method displays a prediction performance better than a k-NN sequence identity-based approach. Furthermore, the developed tool will be a good benchmark for future predictors of antioxidant peptides.


Asunto(s)
Antioxidantes/química , Aprendizaje Profundo , Conservantes de Alimentos/química , Péptidos/química , Secuencia de Aminoácidos , Antioxidantes/farmacología , Conservantes de Alimentos/farmacología , Humanos , Péptidos/farmacología , Programas Informáticos
14.
Rheumatology (Oxford) ; 59(12): 3853-3857, 2020 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-32500148

RESUMEN

OBJECTIVES: Statins are the cornerstone of the treatment and prevention of cardiovascular disease but have been associated with muscular side effects, among others. If patients are not properly evaluated, statin discontinuation may take place, leaving patients' symptoms unresolved and precluding an effective cardiovascular treatment. The present study aims to describe the clinical characteristics, the diagnostic process and the final diagnosis of selected patients with suspected statin-induced myopathy, with quite different alternative diagnoses. METHODS: Among the 86 patients referred to our unit for evaluation since 2012, 6 patients with suspected statin-induced myopathy that was finally ruled out were selected as examples because of their illustrative value. All patients were evaluated in a Muscular Diseases Unit by myology experts, and additional testing was performed according to clinical suspicion. RESULTS: Of the six selected patients with suspected statin-induced myopathy, three had a neurogenic aetiology, two had vacuolar myopathies and one had severe hypothyroidism. Statins were permanently discontinued in two cases, with the treatment of one of the latter patients being continued with a protein convertase subtilisin/kexin type 9 (PCSK9) inhibitor. CONCLUSION: Not all patients taking statins who develop muscle complaints have statin-related myopathy. A thorough clinical evaluation and appropriate testing is warranted to avoid an unnecessary increase in cardiovascular risk.


Asunto(s)
Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Enfermedades Musculares/inducido químicamente , Anciano , Femenino , Humanos , Masculino
15.
Food Chem ; 329: 127148, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-32485647

RESUMEN

The performance of a whey protein hydrolysate (WPH) for producing physically and chemically stable omega-3 emulsions was compared to hydrolysates obtained from other sustainable protein sources such as soy (SPH) and blue whiting (BPH). The oxidative stability of hydrolysate-stabilized emulsions was greatly influenced by their physical stability. Emulsion stabilized with BPH suffered a constant increase in droplet size and BPH was not able to prevent omega-3 oxidation, showing high concentration of volatiles. The peroxide value of SPH emulsion increased after the first day of storage, but it had a lower concentration of volatiles. In contrast, WPH-stabilized emulsion, which did not had any change in droplet size during storage, showed the highest oxidative stability. Therefore, our results confirmed that WPH is an interesting option for physical and oxidative stabilization of omega-3 emulsions, while SPH could be used in emulsions with shorter storage time such as pre-emulsions for microencapsulation of omega-3 oils.


Asunto(s)
Antioxidantes/química , Emulsionantes/química , Proteína de Suero de Leche/química , Animales , Emulsiones , Gadiformes , Oxidación-Reducción , Proteínas de Soja/química , Glycine max/química
16.
Foods ; 9(5)2020 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-32365987

RESUMEN

The influence of the carbohydrate-based wall matrix (glucose syrup, GS, and maltodextrin, MD21) and the storage temperature (4 °C or 25 °C) on the oxidative stability of microencapsulated fish oil was studied. The microcapsules (ca. 13 wt% oil load) were produced by spray-drying emulsions stabilized with whey protein hydrolysate (WPH), achieving high encapsulation efficiencies (>97%). Both encapsulating materials showed an increase in the oxidation rate with the storage temperature. The GS-based microcapsules presented the highest oxidative stability regardless of the storage temperature with a peroxide value (PV) of 3.49 ± 0.25 meq O2/kg oil and a content of 1-penten-3-ol of 48.06 ± 9.57 ng/g oil after six weeks of storage at 4 °C. Moreover, low-fat mayonnaise enriched with GS-based microcapsules loaded with fish oil and containing WPH as a film-forming material (M-GS) presented higher oxidative stability after one month of storage when compared to low-fat mayonnaise enriched with either a 5 wt% fish oil-in-water emulsion stabilized with WPH or neat fish oil. This was attributed to a higher protective effect of the carbohydrate wall once the microcapsules were incorporated into the mayonnaise matrix.

17.
Langmuir ; 36(9): 2300-2306, 2020 03 10.
Artículo en Inglés | MEDLINE | ID: mdl-32068398

RESUMEN

We report on small-angle neutron scattering (SANS) investigations of separate phase domains in high fat (70%) oil-in-water emulsions emulsified with the combination of sodium caseinate (CAS) and phosphatidylcholine (PC). The emulsion as a whole was studied by contrast variation to identify scattering components dominated by individual emulsifiers. The emulsion was subsequently separated into the aqueous phase and the oil-rich droplet phase, which were characterized separately. Emulsions produced with 1.05% (w/w) CAS and PC fraction which varies between 1.75% (w/w) and 0.35% (w/w) provided droplets between 10 and 19 µm in surface weighted mean in 70% fish oil-in-water emulsions. At least two-third of the overall CAS is associated with the interface, while the rest remains with the aqueous phase. Six percent of PC formed a monolayer in the interface, while the rest of the PC remains in the droplet phase in the form of multilayers. When the separated components were resuspended, the resuspended emulsion showed similar characteristics compared to the original emulsion in terms of droplet size distribution and neutron scattering. Instead, CAS in the aqueous phase separated from the emulsion shows aggregation not present in the corresponding CAS-in-D2O system.

18.
Sci Rep ; 10(1): 690, 2020 01 20.
Artículo en Inglés | MEDLINE | ID: mdl-31959786

RESUMEN

In this work, we developed a novel approach combining bioinformatics, testing of functionality and bottom-up proteomics to obtain peptide emulsifiers from potato side-streams. This is a significant advancement in the process to obtain emulsifier peptides and it is applicable to any type of protein. Our results indicated that structure at the interface is the major determining factor of the emulsifying activity of peptide emulsifiers. Fish oil-in-water emulsions with high physical stability were stabilized with peptides to be predicted to have facial amphiphilicity: (i) peptides with predominantly α-helix conformation at the interface and having 18-29 amino acids, and (ii) peptides with predominantly ß-strand conformation at the interface and having 13-15 amino acids. In addition, high physically stable emulsions were obtained with peptides that were predicted to have axial hydrophobic/hydrophilic regions. Peptides containing the sequence FCLKVGV showed high in vitro antioxidant activity and led to emulsions with high oxidative stability. Peptide-level proteomics data and sequence analysis revealed the feasibility to obtain the potent emulsifier peptides found in this study (e.g. γ-1) by trypsin-based hydrolysis of different side streams in the potato industry.


Asunto(s)
Emulsiones/aislamiento & purificación , Ácidos Grasos Omega-3/química , Péptidos/aislamiento & purificación , Solanum tuberosum/metabolismo , Algoritmos , Secuencia de Aminoácidos , Biología Computacional , Emulsiones/química , Aceites de Pescado/química , Interacciones Hidrofóbicas e Hidrofílicas , Péptidos/química , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Estructura Secundaria de Proteína , Proteómica , Solanum tuberosum/química , Agua/química
19.
J Colloid Interface Sci ; 554: 183-190, 2019 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-31299546

RESUMEN

We report on the structural evaluation of high fat fish oil-in-water emulsions emulsified with sodium caseinate (CAS) and phosphatidylcholine (PC). The microemulsions contained 70% (w/w) fish oil with 1.05-1.4% (w/w) CAS and 0.4-1.75% (w/w) PC and were studied by the combination of light scattering together with small-angle X-ray and neutron scattering (SAXS/SANS). Aqueous CAS forms aggregates having a denser core of about 100 kDa and less dense shell about 400 kDa with the hard sphere diameter of 20.4 nm. PC appears as multilayers whose coherence length spans from 40 to 100 nm. PC monolayer separates oil and water phases. Moreover, 80% CAS particles are loosely bound to the interface but are not forming continuous coverage. The distance between aggregated CAS particles in microemulsion is increased compared to CAS aggregates in pure CAS-in-water system. PC multilayers become larger in the presence of oil-water interface compared to the pure PC mixtures. Bilayers become larger with increasing PC concentration. This study forms a structural base for the combination of CAS and PC emulsifiers forming a well-defined thin and dense PC layer together with thick but less dense CAS layer, which is assumed to explain its better oxidative stability compared to single emulsifiers.


Asunto(s)
Caseínas/química , Emulsiones/química , Aceites de Pescado/química , Fosfatidilcolinas/química , Agua/química , Emulsionantes/química
20.
Food Chem ; 289: 490-499, 2019 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-30955641

RESUMEN

This study investigated the effects of modified phosphatidylcholine (PC) with different alkyl chain lengths (PC_C14 and PC_C16) and covalently attached caffeic acid on the physical and oxidative stability of 70% fish oil-in-water emulsions. High fat emulsions were produced using different amounts of modified PCs in combination with sodium caseinate and soy-PC. Results showed that the physical stability of the emulsions was improved with increasing concentrations of modified PCs, due to their high surface activity. Emulsion stabilized with PC_C14 led to smaller droplets and higher viscosity, whereas PC_C16 had higher protein surface load, which may result in a thicker interfacial layer. Modified PCs enhanced the oxidative stability of the emulsions due to the attachment of caffeic acid to the glycerol backbone of PC, which brings the antioxidant in the vicinity of oil-water interface. PC_C16 led to less formation of primary and secondary oxidation products compared to PC_14 at their equivalent concentrations.


Asunto(s)
Ácidos Cafeicos/química , Emulsiones/química , Ácidos Grasos Omega-3/química , Fosfatidilcolinas/química , Antioxidantes/química , Caseínas/química , Estabilidad de Medicamentos , Aceites de Pescado/química , Lecitinas , Oxidación-Reducción , Viscosidad , Agua
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