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1.
Molecules ; 29(6)2024 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-38542963

RESUMO

Pepsin, trypsin and proteinase K were used in the present study to hydrolyse the proteins from whole eggs, yolks or whites, and the resulting hydrolysates were characterised in terms of antioxidant and IgE-binding properties, using a combination of in vitro and in silico methods. Based on the degree of hydrolysis (DH) results, the egg yolk proteins are better substrates for all the tested enzymes (DH of 6.2-20.1%) compared to those from egg whites (DH of 2.0-4.4%). The SDS-PAGE analysis indicated that pepsin and proteinase K were more efficient compared to trypsin in breaking the intramolecular peptide bonds of the high molecular weight egg proteins. For all the tested substrates, enzyme-assisted hydrolysis resulted in a significant increase in antioxidant activity, suggesting that many bioactive peptides are encrypted in inactive forms in the parent proteins. The hydrolysates obtained with proteinase K exhibited the highest DPPH radical scavenging activity (124-311 µM Trolox/g protein) and the lowest residual IgE-binding capacity. The bioinformatics tools revealed that proteinase K is able to break the integrity of the main linear IgE-binding epitopes from ovalbumin and ovomucoid. It can be concluded that proteinase K is a promising tool for modulating the intrinsic properties of egg proteins.


Assuntos
Antioxidantes , Pepsina A , Antioxidantes/química , Tripsina , Endopeptidase K , Peptídeos/química , Proteínas do Ovo/química , Hidrólise , Imunoglobulina E , Hidrolisados de Proteína/química
2.
Molecules ; 28(9)2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37175173

RESUMO

The functionality of the peptides obtained through enzymatic hydrolysis of spent brewer's yeast was investigated. Hydrolysis was carried out for 4-67 h with bromelain, neutrase and trypsin. The resulting hydrolysates were characterized in terms of physical-chemical, antioxidant and techno-functional properties. The solid residues and soluble protein contents increased with the hydrolysis time, the highest values being measured in samples hydrolyzed with neutrase. Regardless of the hydrolysis time, the maximum degree of hydrolysis was measured in the sample hydrolyzed with neutrase, while the lowest was in the sample hydrolyzed with trypsin. The protein hydrolysate obtained with neutrase exhibited the highest DPPH radical scavenging activity (116.9 ± 2.9 µM TE/g dw), followed by the sample hydrolyzed with trypsin (102.8 ± 2.7 µM TE/g dw). Upon ultrafiltration, the fraction of low molecular weight peptides (<3 kDa) released by bromelain presented the highest antioxidant activity (50.06 ± 0.39 µM TE/g dw). The enzymes influenced the foaming properties and the emulsions-forming ability of the hydrolysates. The trypsin ensured the obtaining of proteins hydrolysate with the highest foam overrun and stability. The emulsions based on hydrolysates obtained with neutrase exhibited the highest viscosity at a shear rate over 10 s-1. These results indicate that the investigated proteases are suitable for modulating the overall functionality of the yeast proteins.


Assuntos
Antioxidantes , Peptídeo Hidrolases , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Peptídeo Hidrolases/química , Bromelaínas , Saccharomyces cerevisiae/metabolismo , Tripsina/metabolismo , Proteínas/metabolismo , Peptídeos/química , Hidrólise , Hidrolisados de Proteína/química
3.
Molecules ; 25(3)2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32046151

RESUMO

Manufacturing beer with a high biological value requires identifying new methods for increasing the health-enhancing compounds level. The aim of this study was to increase the biological value of beer by adding antioxidant-rich eggplant (Solanum melongena L.) peel extract (EPE). The total phenolic content (TPC), total flavonoid content (TFC), and total monomeric anthocyanin content (TMA) were determined. Moreover, the antioxidant activity was evaluated by different radical scavenging assays. The addition of different levels of EPE resulted in a significant increase of TPC and TFC of beer samples from 0.426 to 0.631 mg GAE/mL, and from 0.065 to 0.171 mg CE/mL, respectively. The EPE-supplemented beer samples developed a reddish color because of the presence of anthocyanin pigments. The TMA content of beer varied from 0.011 to 0.083 mg D3G/mL with the level of added EPE. The HPLC analysis indicated that the anthocyanins prevailing in the eggplant peels were delphinidin-3-rutinoside, delphininidin-3-glucoside and delphinidin-3-rutinoside-5-glucoside. The radical scavenging assays indicated a linear increase of the antioxidant activity following EPE addition, without altering the physicochemical parameters of the beer. These results are promising for using the EPE as a functional ingredient for beer production.


Assuntos
Cerveja , Extratos Vegetais/química , Solanum melongena/química , Antocianinas/química , Antioxidantes/química , Cromatografia Líquida de Alta Pressão/métodos , Cor , Flavonoides/química , Hipersensibilidade Alimentar , Frutas/química , Glucosídeos/química , Fenóis/química , Pigmentos Biológicos/química
4.
Molecules ; 25(21)2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33126733

RESUMO

Lavender flowers were used in this study as a source of phytochemicals as naturally occurring antioxidants. Two different extraction techniques were applied, such as ultrasound-assisted (UAE) and supercritical fluids (SCE) methods. The comparative evaluation of the phytochemicals profile evidenced a higher content of chlorophyll a and b of 5.22 ± 0.12 mg/g dry weight (D.W.) and 2.95 ± 0.16 mg/g D.W, whereas the carotenoids content was 18.24 ± 0.04 mg/g D.W. in the SCE extract. Seven main compounds were found in both extracts: ß-linalool, eucalyptol, linalool acetate, ß-trans-ocimene, and limonene in SCE and linalool acetate, ß-linalool, 6-methyl-2-(2-oxiranyl)-5-hepten-2-ol, linalool oxide, lavandulyl acetate and camphor in UAE. The (n-3) acids had a higher contribution in SCE. The extracts were microencapsulated in different combinations of wall materials based on polysaccharides and milk proteins. The four variants showed different phytochemical and morphological profiles, with a better encapsulating efficiency for proteins (up to 98%), but with a higher content of encapsulated carotenoids for polysaccharides, the latter showing remarkable antimicrobial activity against selected microorganisms. Carboxymethyl cellulose and whey proteins led to a double encapsulation of lipophilic compounds. The powders were tested in two food matrices as ingredients, with multiple targeted functions, such as flavoring, antimicrobial, antioxidant activity that can successfully replace synthetic additives.


Assuntos
Alimentos , Lavandula/química , Compostos Fitoquímicos/farmacologia , Cápsulas , Flores/química , Compostos Fitoquímicos/química
5.
Luminescence ; 34(7): 739-748, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31304679

RESUMO

ß-Lactoglobulin has been shown to interact with carotenoids from sea buckthorn berries. However, previously, no studies have taken into account the effect of calcium and magnesium on the ß-lactoglobulin-carotenoids complex. This study aims to determine the effect of calcium and magnesium on the interaction between ß-lactoglobulin and carotenoids from sea buckthorn berries extract, during heating from the perspective of deepening interaction mechanisms as prerequisites for micro- and nanoencapsulation. Phase diagram, intrinsic fluorescence spectra, quenching experiments and synchronous spectra were employed to acquire information regarding the conformation of protein in the presence of calcium chloride and magnesium chloride. Intrinsic fluorescence data showed that, between 25°C and 60°C, the presence of calcium chloride in the complex favoured the movement of tryptophan residues to domains located at the protein-water interface, while magnesium chloride favoured the burial of tryptophan residues. Higher temperatures generated blue shifts regardless of which salt was present, suggesting exposure of tryptophan residues to the hydrophobic core of the protein. Extrinsic fluorescence intensity of the non-heat-treated complex with magnesium chloride was significantly higher (P < 0.01) than of the complex with calcium chloride, suggesting that 1-anilino-8-naphtalenesulphonic acid was bound to a higher proportion of the ß-lactoglobulin-carotenoids complex. Calcium chloride increased extrinsic fluorescence to a greater extent than magnesium chloride at temperatures above 70°C and was related to small structural changes induced by preheating ß-lactoglobulin.


Assuntos
Cloreto de Cálcio/química , Hippophae/química , Lactoglobulinas/química , Cloreto de Magnésio/química , Carotenoides/química , Espectrometria de Fluorescência , Temperatura
6.
Molecules ; 24(18)2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31540422

RESUMO

The aqueous anthocyanin-rich extract derived from black rice (Oryza sativa L.) was encapsulated by freeze drying using milk proteins and peptides as coating materials. The molecular modelling approach indicated that all major casein fractions and whey proteins were able to bind at least one anthocyanin molecule. The hydrophobic interactions and hydrogen bonding across the interfaces appeared to be mainly responsible for the stabilizations of the complexes formed between the coating material and bioactive compounds. Two dark purple colored powders, differentiated by the ratio of the encapsulation materials used, rich in phytochemicals were obtained, with an encapsulation efficiency of up to 99%. The powders were tested for antioxidant activity, cytocompatibility, and thermal stability. The morphological structure of the powders highlighted the presence of encapsulated anthocyanins. Both powders showed a remarkable antioxidant activity of about 46 mM Trolox/g D.W., and cytocompatibility on the L929 fibroblast culture. At certain concentrations, both powders stimulated cell proliferation. The powders showed a good thermal stability between 75 and 100 °C for 15 min. The powders were tested in a food model system and checked for stability of phytochemicals during storage. The added value of the powders was demonstrated throughout the antioxidant activity, which remained unchanged during storage.


Assuntos
Antocianinas , Proliferação de Células/efeitos dos fármacos , Fibroblastos/metabolismo , Oryza/química , Extratos Vegetais , Animais , Antocianinas/química , Antocianinas/farmacologia , Cápsulas , Linhagem Celular , Fibroblastos/citologia , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Extratos Vegetais/química , Extratos Vegetais/farmacologia
7.
J Sci Food Agric ; 98(8): 3119-3128, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29210457

RESUMO

BACKGROUND: Ovomucoid (OVM) is the dominant allergen found in egg white. The heat-induced changes on chicken OVM structure and antigenic properties were assessed at acidic, neutral and alkaline pH values. RESULTS: The fluorescence spectroscopy measurements indicated changes in the conformation of OVM caused by both pH and thermal treatment. The OVM molecule exhibited higher exposure of hydrophobic residues at 7.0, as indicated by the synchronous spectra, intrinsic fluorescence and quenching experiments. When heating the protein at pH 9.5, the molecular structure appeared more compact. The antigenic properties of OVM, estimated through the enzyme-linked immunosorbent assay, appeared not to be sensitive to heat at pH 7.0 and 4.5. Single molecule level investigations indicated that the secondary and tertiary structure of OVM was affected by the thermal treatment. CONCLUSIONS: Experimental results indicated over 90% reduction of the antigenicity at pH 9.5 and temperature of 100 °C. Significant changes of the linear epitopes exposure and location of the conformational epitopes were highlighted after performing heating molecular dynamics simulations of OVM from 25 °C to 100 °C. © 2017 Society of Chemical Industry.


Assuntos
Ovomucina/química , Ovomucina/imunologia , Alérgenos/química , Alérgenos/imunologia , Animais , Galinhas , Ensaio de Imunoadsorção Enzimática , Epitopos/química , Epitopos/imunologia , Temperatura Alta , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Conformação Proteica
8.
J Sci Food Agric ; 96(6): 1906-14, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26058827

RESUMO

BACKGROUND: In the food industry, glucose oxidase (GOX) is used to improve the shelf life of food materials. The pH- and heat-induced conformational changes of glucose oxidase from Aspergillus niger were quantified by means of fluorescence spectroscopy and molecular dynamics simulations. RESULTS: The phase diagram showed an all-or-none transition process, indicating that pH and temperature largely influence the conformational state of GOX. Shifts in maximum wavelength of Trp, Tyr were registered as the protein encounters a lower pH (pH 4.0), suggesting significant changes of the polarity around the chromophore molecule. Quenching experiments using KI showed higher quenching constants of Trp and flavin adenine dinucleotide upon heating or by changing pH value, and were mainly correlated with the conformational changes upon protein matrix. Finally, valuable insights into the thermal behaviour of GOX were obtained from molecular modelling results. CONCLUSIONS: The conformation and structure of GOX protein is dependent upon the pH and heat treatment applied. Molecular dynamics simulation indicated significant changes in the substrate binding region at temperatures over 60 °C that might affect enzyme activity. Moreover, an important alteration of the small pocket hosting the positively charged His(516) residue responsible for oxygen activation appears evident at high temperatures.


Assuntos
Glucose Oxidase/metabolismo , Temperatura Alta , Modelos Químicos , Espectrometria de Fluorescência/métodos , Aspergillus niger/enzimologia , Simulação por Computador , Glucose Oxidase/genética , Concentração de Íons de Hidrogênio , Conformação Proteica
9.
Food Sci Technol Int ; 21(5): 342-53, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24837596

RESUMO

Millet has long been known as a good source of fiber and antioxidants, but only lately started to be exploited by food scientists and food industry as a consequence of increased consumer awareness. In this study, doughs and breads were produced using millet flour in different ratios (10, 20, 30, 40, and 50%) to white, dark, and whole wheat flour. The flour blends were evaluated in terms of rheological and thermo-mechanical properties. Fundamental rheological measurements revealed that the viscosity of the flour formulations increases with wheat flour-extraction rate and decreases with the addition of millet flour. Doughs behavior during mixing, overmixing, pasting, and gelling was established using the Mixolab device. The results of this bread-making process simulation indicate that dough properties become critical for the flour blends with millet levels higher than 30%. The breads were evaluated for volume, texture, and crumb-grain characteristics. The baking test and sensory evaluation results indicated that substitution levels of up to 30% millet flour could be used in composite bread flour. High levels of millet flour (40 and 50%) negatively influenced the loaf volume, crumb texture, and taste.


Assuntos
Culinária , Farinha/análise , Temperatura Alta , Panicum/química , Triticum/química , Mecânica , Reologia , Fatores de Tempo
10.
J Food Sci Technol ; 52(12): 8095-103, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26604382

RESUMO

Linoleic acid (LA) is the precursor of bioactive oxidized linoleic acid metabolites and arachidonic acid, therefore is essential for human growth and plays an important role in good health in general. Because of the low water solubility and sensitivity to oxidation, new ways of LA delivery without compromising the sensory attributes of the enriched products are to be identified. The major whey protein, ß-lactoglobulin (ß-Lg), is a natural carrier for hydrophobic molecules. The thermal induced changes of the ß-Lg-LA complex were investigated in the temperature range from 25 to 85 °C using fluorescence spectroscopy techniques in combination with molecular modeling study and the results were compared with those obtained for ß-Lg. Experimental results indicated that, regardless of LA binding, the polypeptide chain rearrangements at temperatures higher than 75 °C lead to higher exposure of hydrophobic residues causing the increase of fluorescence intensity. Phase diagram indicated an all or none transition between two conformations. The LA surface involved in the interaction with ß-Lg was about 497 Çº(2), indicating a good affinity between those two components even at high temperatures. Results obtained in this study provide important details about heat-induced changes in the conformation of ß-Lg-LA complex. The thermal treatment at high temperature does not affect the LA binding and carrier functions of ß-Lg.

11.
J Food Sci Technol ; 52(10): 6290-300, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26396374

RESUMO

The heat induced conformational changes of calf alkaline phosphatase (ALP) were analyzed using different methods, based on fluorescence spectroscopy, molecular modeling and inactivation studies. Experimental studies were conducted in buffer solution in the temperature range between 25 and 70 °C. Molecular dynamic (MD) simulation provided details on thermally induced changes in ALP structure, highlighting that heating favored the hydrophobic exposure and important alteration of the catalytic site above 60 °C. Additional information to MD data were obtained by using different fluorescence spectroscopy methods, which revealed a complex mechanism of thermal denaturation. Therefore, the emissive properties indicated an unfolding of ALP at temperatures below 60 °C, whereas at higher temperatures, the polypeptides chains fold leading to a higher exposure of Trp residues. In order to establish a structure-function relationship, the results were correlated with inactivation studies of ALP in buffer at pH 9.0. The inactivation data were fitted using a first-order kinetic model, resulting in an activation energy value of 207.26 ± 21.68 kJ · mol(-1).

12.
J Sci Food Agric ; 94(11): 2338-44, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24425348

RESUMO

BACKGROUND: Tyrosinases are involved in enzymatic browning reactions in damaged fruits during post-harvest handling and processing. The overall structure of tyrosinase from Agaricus bisporus mushrooms at different pH values was monitored using fluorescence spectroscopy and molecular dynamics simulations. RESULTS: When the pH value was increased from 6.0 to 9.0, the protein passed through several structural intermediates, including the tetramer, trimer and dimer stages. Changes in the secondary and tertiary structure of tyrosinase at neutral pH were outlined after running molecular dynamics simulations. A detailed check at the single-molecule level by means of molecular modeling tools suggested that the most important contribution to the fluorescence intensity is given by the H subunits with seven Trp and nine Tyr residues exposed to the solvent, whereas the lectin-like folded L subunits have only six Trp and three Tyr residues, of which only Trp(15) , Trp(59) and Trp(93) are partially exposed to the solvent. CONCLUSIONS: The results indicated that the enzyme was sensitive to pH. The experimental results revealed the unfolding of the native tetrameric enzyme in acidic pH range, causing exposure of the hydrophobic residues.


Assuntos
Agaricus/enzimologia , Frutas/microbiologia , Proteínas Fúngicas/química , Monofenol Mono-Oxigenase/química , Doenças das Plantas/microbiologia , Sequência de Aminoácidos , Aminoácidos , Simulação por Computador , Fluorescência , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Modelos Moleculares , Conformação Proteica , Dobramento de Proteína , Espectrometria de Fluorescência
13.
Antioxidants (Basel) ; 13(5)2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38790675

RESUMO

Valorisation of food by-products, like spent brewer's yeast and fruit pomaces, represents an important strategy for contributing to sustainable food production. The aims of this study were to obtain Maillard conjugates based on spent yeast protein hydrolysate (SYH) with dextran (D) or maltodextrin (MD) by means of ultrasound treatment and to use them for developing encapsulation systems for the anthocyanins from aronia pomace. The ultrasound-assisted Maillard conjugation promoted the increase of antioxidant activity by about 50% compared to conventional heating and SYH, and was not dependent on the polysaccharide type. The ability of the conjugates to act as wall material for encapsulating various biologically active compounds was tested via a freeze-drying method. The retention efficiency ranged between 58.25 ± 0.38%-65.25 ± 2.21%, while encapsulation efficiency varied from 67.09 ± 2.26% to 88.72 ± 0.33%, indicating the strong effect of the carrier material used for encapsulation. The addition of the hydrolysed yeast cell wall played a positive effect on the encapsulation efficiency of anthocyanins when used in combination with the SYH:MD conjugates. On the other hand, the stability of anthocyanins during storage, as well as their bioavailability during gastrointestinal digestion, were higher when using the SYH:D conjugate. The study showed that hydrolysis combined with the ultrasound-assisted Maillard reaction has a great potential for the valorisation of spent brewer's yeast as delivery material for the encapsulation of bioactive compounds.

14.
Plants (Basel) ; 13(11)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38891255

RESUMO

It has been discovered that the peel of a pumpkin (Cucurbita maxima), regarded as a waste product of pumpkin processing, has significant amounts of carotenoids and other antioxidants. This study aims to identify the most effective extraction parameters for an ultrasonic-assisted extraction method to extract the total carotenoids (TCs) and assess the antioxidant activity (AA) of pumpkin peel. To determine the effects of the extraction time, temperature, and material-to-solvent ratio on the recovery of TCs and AA, a response surface methodology utilizing the central composite design (CCD) was used. The extraction temperature (6.25-98.75 °C), extraction duration (13.98-128.98 min), and solvent ratio (0.23-50.23 mL) were the variables studied in the coded form of the experimental plan. The carotenoid concentration varied from 0.53 to 1.06 mg/g DW, while the AA varied from 0.34 to 7.28 µM TE/g DW. The findings indicated that the optimal extraction parameters were an 80 °C temperature, a 10 mL solvent ratio, and a 100 min extraction time. The study confirmed that the optimum extraction conditions resulted in an experimental TC yield of 0.97 mg/g DW and an AA of 7.25 µM TE/g DW. Overall, it should be emphasized that the extraction process can be enhanced by setting the operating factors to maximize the model responses.

15.
J Sci Food Agric ; 93(4): 794-802, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-22836726

RESUMO

BACKGROUND: Knowledge of transglutaminase behaviour at thermal treatment allows efficient applications in food processing. The heat-induced conformational changes of microbial transglutaminase were studied by fluorescence spectroscopy and a molecular modelling approach. RESULTS: The experimental results indicate the unfolding of transglutaminase in a single-phase reaction, at temperatures over 60 °C. The incidence of conformational changes is also supported by the increase of both intrinsic and 1-anilino-8-naphthalene sulfonate fluorescence intensity with temperature. Changes in the secondary and tertiary structure of transglutaminase were outlined after running molecular dynamics simulations at temperatures ranging from 25 °C to 80 °C. CONCLUSION: The motif's particularities varied with the temperature, suggesting structural rearrangements of the protein, mainly in helices. The largest deviation from the structure equilibrated at 25 °C was observed at 80 °C.


Assuntos
Proteínas de Bactérias/química , Microbiologia de Alimentos , Temperatura Alta , Transglutaminases/química , Simulação por Computador , Manipulação de Alimentos , Humanos , Desnaturação Proteica , Dobramento de Proteína , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Espectrometria de Fluorescência
16.
Foods ; 12(19)2023 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-37835241

RESUMO

Conjugation of the proteins with carbohydrates, occurring in the early stages of the Maillard reactions, received increased attention because of the high potential to ensure the improvement of the biological activity and functional properties of the proteins of different origins. The Maillard conjugates are conventionally formed through wet or dry heating, but the use of alternative technologies involving ultrasound, microwave, pulsed electric fields, high-pressure, or electrodynamic treatments appears to be efficient in accelerating the reaction steps and limiting the formation of toxic compounds. An overview of the mechanisms of these processing technologies, the main parameters influencing the Maillard conjugate formation, as well as their advantages and disadvantages, is provided in this paper. Different strategies employing these alternative technologies are reported in the literature: as pretreatment of the proteins, either alone or in admixture with the carbohydrates, followed by conventional heating, as a single alternative treatment step, or as a combination of heating and alternative processing. The desired functional properties of the proteins can be achieved by selecting the appropriate processing strategy and optimizing the reaction parameters. Moreover, alternative technologies can be exploited to obtain Maillard conjugates with remarkable biological activity in terms of antioxidant, antimicrobial, antihypertensive, anti-inflammatory, antimutagenic, or bifidogenic properties.

17.
J Food Sci ; 88(12): 5026-5043, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37872831

RESUMO

In this study, a comprehensive approach to advance the inhibitory effect of Hibiscus sabdariffa extract on apple polyphenol oxidase (PPO) was performed. PPO was extracted, purified, and characterized for optimal activity, whereas response surface methodology generated a quadratic polynomial model to fit the experimental results for hibiscus extraction. The optimum conditions allowed to predict a maximum recovery of anthocyanins (256.11 mg delphinidin-3-O-glucoside/g), with a validated value of 272.87 mg delphinidin-3-O-glucoside/g dry weight (DW). The chromatographic methods highlighted the presence of gallic acid (36,812.90 µg/g DW extract), myricetin (141,933.84 µg/g DW extract), caffeic acid (101,394.07 µg/g DW extract), sinapic acid (1157.46 µg/g DW extract), kaempferol (2136.76 µg/g DW extract), and delphinidin 3-O-ß-d-glucoside (226,367.08 µg/g DW extract). The inactivation of PPO followed a first-order kinetic model. A temperature-mediated flexible fit between PPO and anthocyanins was suggested, whereas the molecular docking tests indicated that PPO is a good receptor for cafestol, gallic acid, and catechin, involving hydrophobic and hydrogen bond interactions. PRACTICAL APPLICATION: It is well known that enzymatic browning is one of the most important challenges in the industrial minimal processing of selected fruit and vegetable products. Novel inhibitors for polyphenol oxidase are proposed in this study by using an anthocyanin-enriched extract from Hibiscus sabdariffa L. Based on our results, combining the chemical effect of phytochemicals from hibiscus extract with different functional groups with minimal heating could be an interesting approach for the development of a new strategy to inhibit apple polyphenol oxidase.


Assuntos
Antocianinas , Hibiscus , Antocianinas/análise , Hibiscus/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Catecol Oxidase , Simulação de Acoplamento Molecular , Ácido Gálico , Glucosídeos
18.
Curr Res Food Sci ; 6: 100449, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36798950

RESUMO

The supercritical fluids extraction (SFE) was used to extract the oleoresins from rosehip, followed by an in-depth phytochemical analysis and the development of two design-customized powders for different food and pharmaceutical applications. The SFE experiments allowed obtaining an oleoresins extraction yield of 11.85%. Two fractions were separated (S40 and S45), with significantly different phytochemical profile (p < 0.05), highlighting the efficiency of extraction of fatty acids in S40 extract, whereas the extraction of polyphenols, phytosterols, carotenoids and polyphenols was favored in S45 extract. The phytochemical profile revealed that the linoleic acid (C18:2) and α-linolenic acid (C18:3) represented approximatively 82% and 58% from the total fatty acid content in S40 and S45, respectively. α-Tocopherol and γ-tocopherol prevailed in both extract fractions, with a higher concentration in S45 (229.66 mg/g dry matter (DM) and 112.36 mg/g DM, respectively), whereas ß-sitosterol was the major phytosterol in S45 fraction (118.75 mg/g DM). The S40 fraction was used to design two microencapsulated powders, by combining emulsification, complex coarcevation and freeze-drying. In order to develop new wall materials, with unique properties, the soy protein isolates were used for cross-linked reactions, by using an approach in one step (transglutaminase mediated) (coded as N) and two-steps (heat-induced and transglutaminase mediated) (coded as T). The N powder showed a better phytochemical content, leading to a higher antioxidant activity (5.27 mM Trolox equivalents/g DM), whereas for variant T, the bioactive were apparently doubled encapsulated.

19.
Foods ; 11(13)2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35804671

RESUMO

Seven commercial gluten-free (rice, oat, sorghum, foxtail millet, amaranth, quinoa, and buckwheat) flours were investigated in this study from the point of view of thermo-mechanical properties and solvent retention capacity (SRC). Each flour was used to prepare doughs with specific water absorption (WA) to get a consistency of 1.1 Nm (WA1) and doughs with WA2 levels higher than 85% to ensure a sufficient amount of water in the system for allowing the hydration of all components of the flours. Different correlations were established between proteins, ash, pentosans, damaged starch, and amylose contents on the one hand, and the capacity of the flour samples to retain different solvents such as sucrose, sodium carbonate and CaCl2 on the other hand. Although no significant correlation was found between the protein content of the flours and lactic acid-SRC, the mechanical weakening of the protein was significantly correlated with lactic acid-SRC for both tested WA levels. The doughs with WA1 had higher starch gelatinization and hot gel stability values compared to the corresponding dough systems with a higher water amount. Moreover, lower starch retrogradation and setback torques were obtained in the case of the dough prepared with higher amounts of water.

20.
Food Chem X ; 15: 100374, 2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-35782960

RESUMO

In this study, red onion skin extract was used to obtain food ingredients. Complex biopolymeric matrices were dissolved in the anthocyanin-rich aqueous extract, followed by gelation and freeze-drying. Powders were characterized regarding encapsulation efficiency (EE), phytochemical content, color, antioxidant activity, and microstructure. Storage and simulated digestion stability were also assessed. Two powders with high contents of bioactives and antioxidant activity were obtained. The highest EE was acquired for the powder with a higher polysaccharides concentration (V2). In addition, V2 exhibited the best storage stability. The in vitro studies demonstrated that increased carbohydrate concentration delivers the best anthocyanins protection. To prove its functionality, V2 was added to a salad dressing. The addition of powder has improved the concentration of biologically active compounds and the antioxidant activity of the salad dressings. These results support the assumption that microencapsulation may deliver bioactives from red onion skin as functional ingredients for value-added foods.

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