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1.
Food Chem ; 312: 126035, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31901822

RESUMO

In this study, we investigated the ability of Enterococcus faecalis 2/28, isolated from artisan cheese, to release biopeptides from whey proteins. We used an in silico approach for predicting the bioactivities of peptides generated by E. faecalis. The results of the in vitro study showed that the whey protein hydrolysates (WPHs) obtained had angiotensin-I-converting enzyme (ACE) and dipeptidyl peptidase IV (DPP-IV) inhibitory activities, with inhibition of ACE being stronger than that of DPP-IV. To identify peptides that may be potential inhibitors of ACE, WPH with the highest ACE inhibitory activity was analysed using Sephadex G-75 gel filtration chromatography, Superdex peptide 10/300 GL size exclusion chromatography, and liquid chromatography-electrospray ionisation tandem mass spectrometry (LC-ESI-MS/MS). Among the identified peptides were ACE-inhibitory peptides (LDAQSAPLR, LKGYGGVSLPEW, and LKALPMH), antimicrobial peptides (AASDISLLDAQSAPLR, IIAEKTKIPAVF, IDALNENK, and VLVLDTDYK), DPP-IV-inhibitory peptides (LKALPMH, LKPTPEGDLEIL, LKGYGGVSLPE, LKPTPEGDLE, ILDKVGINY, and VLVLDTDYK), proliferation stimulating peptide (IDALNENK), and cytotoxic peptide (LIVTQTMK).


Assuntos
Enterococcus faecalis/enzimologia , Lactobacillales/enzimologia , Proteínas do Soro do Leite/metabolismo , Soro do Leite/metabolismo , Animais , Bovinos , Dipeptidil Peptidase 4/metabolismo , Hidrólise , Peptidil Dipeptidase A/metabolismo , Hidrolisados de Proteína/química , Hidrolisados de Proteína/metabolismo , Proteólise , Espectrometria de Massas em Tandem , Soro do Leite/química , Proteínas do Soro do Leite/química
2.
J Sci Food Agric ; 100(4): 1711-1717, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31803934

RESUMO

BACKGROUND: Innovative approaches to combine whey with other ingredients and the use of new techniques in product development should be explored to meet consumers' needs and expectations. However, the question arises here of whether whey protein could be used as a suitable food matrix for supplementation with ß-glucan, an attractive glucose polymer and a physiologically functional component. The present study addresses the challenge associated with the design and characterization of whey protein spread as a substrate for ß-glucan delivery. The results are discussed on the basis of physical-chemical and microbiological characteristics, which are subsequently linked to its sensorial profile. RESULTS: A whey protein spread can be developed without the addition of NaCl, with physicochemical characteristics (pH, viscosity), microbiological counts, and sensory acceptance (color, aroma, overall impression) similar to the product with NaCl. This spread can be refrigerated for 28 days. The whey protein spread presented high whey protein content (18.67-19.17 g 100 g-1 ) and could be a good source of carbohydrates (8.30-8.68 g 100 g-1 ), with low levels of fat (0.2 g 100 g-1 ) and lactose (1.56-1.61 g 100 g-1 ). The sensorial results showed that women would prefer a product with lower salt content. CONCLUSION: This is the first study to evaluate the development of a whey protein spread enriched with ß-glucan, providing results that are of interest for the dairy sector. The combination of whey and ß-glucan can be explored industrially as a whey protein spread, with satisfactory results for physicochemical, microbiological, and sensory acceptance. © 2019 Society of Chemical Industry.


Assuntos
Proteínas do Soro do Leite/química , beta-Glucanas/análise , Adolescente , Adulto , Feminino , Manipulação de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Masculino , Pessoa de Meia-Idade , Paladar , Viscosidade , Soro do Leite/química , Soro do Leite/metabolismo , Proteínas do Soro do Leite/metabolismo , Adulto Jovem , beta-Glucanas/metabolismo
3.
Appl Biochem Biotechnol ; 190(1): 182-196, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31313242

RESUMO

The present study aimed to improve the survivability of L. acidophilus encapsulated in alginate-whey protein isolate (AL-WPI) biocomposite under simulated gastric juice (SGJ) and simulated intestinal juice (SIJ). Microcapsules were prepared based on emulsification/internal gelation technique. Optimal compositions of AL and WPI and their ratio in the aqueous phase were evaluated based on minimizing mean diameter (MD) of the microcapsules and maximizing encapsulation efficiency (EE), survivability of cells under SGJ (Viability), and release of viable cells under SIJ (Release) using Box-Behnken experimental design. Optimal composition comprising 4.54% (w/v) AL, 10% (w/v) WPI, and 10% (v/v) AL-WPI gum in the aqueous phase was determined statistically. Physicochemical characteristics of the optimized matrix were investigated by SEM, FTIR, and XRD analysis to determine surface morphology, molecular bonds, and crystalline nature of such hydrocolloid. It could be concluded that the proposed biocomposite is a good promise for nutrients encapsulation in the food industry.


Assuntos
Alginatos/química , Cápsulas , Lactobacillus acidophilus/fisiologia , Probióticos , Proteínas do Soro do Leite/química , Contagem de Colônia Microbiana , Composição de Medicamentos/métodos , Lactobacillus acidophilus/isolamento & purificação
4.
Crit Rev Food Sci Nutr ; 60(1): 64-83, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-30632771

RESUMO

Mucins are long glycoprotein molecules responsible for the gel nature of the mucous layer that covers epithelial surfaces throughout the body. Mucins, as the major salivary proteins, are also important proteins for the food oral processing and digestion. The interactions of salivary mucins and saliva with several food proteins and food protein emulsions, as well as their functional properties related to the food oral processing were reviewed in this paper. The target food proteins of focus were whey proteins (lactoferrin and beta-lactoglobulin) and non-whey proteins (casein, gelatin, galectin/lectin, and proline-rich proteins). Most of the studies suggest that electrostatic attraction (between positively charged food proteins with negatively charged moieties of mucin mainly on glycosylated region of mucin) is the major mode of interaction between them. On the other hand, casein attracts the salivary proteins only via non-covalent interactions due to its naturally self-assembled micellar structure. Moreover, recent studies related to ß-lactoglobulin (BLG)-mucin interactions have clarified the importance of hydrophobic as well as hydrophilic interactions, such as hydrogen bonding. Furthermore, in vitro studies between protein emulsions and saliva observed a strong aggregating effect of saliva on caseinate and whey proteins as well as on surfactant-stabilized emulsions. Besides, the sign and the density of the charge on the surface of the protein emulsion droplets contribute significantly to the behavior of the emulsion when mixed with saliva. Other studies also suggested that the interactions between saliva and whey proteins depends on the pH in addition to the flow rate of the saliva. Overall, the role of interactions of food proteins and food protein emulsions with mucin/saliva-proteins in the oral perception, as well as the physicochemical and structural changes of proteins were discussed.


Assuntos
/química , Mucinas/química , Saliva/química , Proteínas e Peptídeos Salivares/química , Caseínas , Galectinas , Gelatina , Humanos , Lactoferrina , Lactoglobulinas/química , Proteínas do Soro do Leite/química
5.
Carbohydr Polym ; 227: 115337, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31590880

RESUMO

A gel delivery system was developed in the present work using whey protein isolate and lotus root amylopectin via regulating pH. The texture, thermodynamics, rheology and microstructure of gels were evaluated. Results showed that pH at 7.0 induced a more compact and stable gel structure than other pH. The composite gel formed at pH 7.0 was accordingly employed to encapsulate vitamin D3. Results exhibited that the encapsulation of composite gel of whey protein isolate and lotus root amylopectin could enhance the storage stability of vitamin D3 and protect vitamin D3 from photochemical degradation. Moreover, this encapsulation could control the release of vitamin D3 in simulated intestinal fluid. Animal experiments exhibited that the bioavailability was significantly increased after vitamin D3 was encapsulated by the composite gel. This work indicated that the whey protein isolate-lotus root amylopectin gel is a good delivery system to improve the stability and bioavailability of vitamin D3.


Assuntos
Amilopectina/administração & dosagem , Colecalciferol/administração & dosagem , Sistemas de Liberação de Medicamentos , Vitaminas/administração & dosagem , Proteínas do Soro do Leite/administração & dosagem , Amilopectina/química , Amilopectina/farmacocinética , Animais , Disponibilidade Biológica , Colecalciferol/química , Colecalciferol/farmacocinética , Estabilidade de Medicamentos , Géis , Absorção Intestinal/efeitos dos fármacos , Lotus , Masculino , Camundongos Endogâmicos C57BL , Raízes de Plantas , Vitaminas/química , Vitaminas/farmacocinética , Proteínas do Soro do Leite/química , Proteínas do Soro do Leite/farmacocinética
6.
Food Chem ; 309: 125758, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31699551

RESUMO

Emulsions were designed under low frequency ultrasound (20 kHz) at energy densities of 11.7-117.0 J/mL using grape seed oil and milk protein solutions containing different casein to whey protein ratios of 80:20, 60:40, 50:50 and 40:60. An increase in energy densities produced emulsions with a smaller droplet size and narrow size distribution at all milk protein ratios. However, the minimum sono-energy density required to produce stable emulsions varied depending on the ratio of caseins (CN) and whey proteins (WP) in the continuous phase. In addition, the composition of the interfacial layer was dependent on the composition of the milk proteins in the continuous phase. The interfacial layer was predominantly covered by the CN and CN-WP aggregates in the presence of equal or greater amounts of caseins than whey proteins (80:20, 60:40 and 50:50), while WP aggregates and CN-WP aggregates were the primary constituents of whey protein-rich emulsions (40:60).


Assuntos
Emulsões/química , Proteínas do Leite/química , Óleos Vegetais/química , Vitis/metabolismo , Caseínas/química , Tamanho da Partícula , Sementes/metabolismo , Sonicação , Proteínas do Soro do Leite/química
7.
Food Chem ; 309: 125757, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31699562

RESUMO

Impacts of superfine grinding treatment (0, 2, 4, 6, 8 or 10 h) on structure, physicochemical and rheological properties of transglutaminase (TGase)-crosslinked whey protein isolate (WPI) were investigated. Size exclusion chromatography showed that high molecular weight polymers were formed in TGase-treated sWPI (WPI treated with superfine grinding), whereas its consumption of free amino groups reached the maximum at grinding 8 h and 10 h. With the milling time extended from 0 to 10 h, particle size of the TGase-crosslinked sWPI gradually increased. Emission spectrum shifted from 338.6 nm to 340.6 nm after sWPI treated with TGase. Meanwhile, TGase-crosslinked sWPI had higher apparent viscosity, emulsifying properties than TGase-crosslinked WPI, but the solubility of TGase-crosslinked sWPI was lower than sWPI. Superfine grinding treatment remarkably increased ß-sheet and random compositions in TGase-crosslinked sWPI. These findings indicated that superfine grinding treatment could enhance the TGase cross-linking degree, and improve rheological properties in TGase-crosslinked WPI.


Assuntos
Transglutaminases/metabolismo , Proteínas do Soro do Leite/metabolismo , Emulsões/química , Peso Molecular , Tamanho da Partícula , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Reologia , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Viscosidade , Proteínas do Soro do Leite/química
8.
J Sci Food Agric ; 100(1): 287-294, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31525263

RESUMO

BACKGROUND: Diacylglycerol (DAG) reduces body weight, suppresses body fat accumulation, and lowers the blood lipid concentration, and docosahexaenoic acid (DHA) can reduce the risk of occurrence of coronary artery diseases. RESULTS: DAG-rich algae oil with a high DHA content (55.9%) was synthesized via the lipase-catalyzed glycerolysis of algae oil, which consisted of triacylglycerol (43.9 mol%), DAG (40.9 mol%), and monoacylglycerol (15.2 mol%). The DAG-rich algae oil-in-water emulsions were prepared using three emulsifiers [whey protein concentrate (WPC), Tween80, and Tween80 + Span80]. The WPC-emulsion formed a thicker serum layer (6.67% at day 51) and larger oil droplets (d32 , 0.37 µm at day 28) than the Tween80- and Tween80 + Span80-emulsions (3.33-4.17%; 0.26 µm), and an upper cream layer with excess oil droplets was observed in only the WPC-emulsion, indicating that WPC-emulsion possesses the lowest emulsification stability. The hydroperoxide value and reduction rate of the DHA content were higher in the WPC-emulsions than in the Tween80- and Tween80 + Span80-emulsions during storage, which suggested that the WPC-emulsion had the lowest oxidation stability. CONCLUSION: The DAG-rich algae oil-in-water emulsion prepared with suitable emulsifiers, such as non-ionic emulsifiers, would have excellent emulsification and oxidative stabilities and provides a health benefit for special purposes in the food processing industry. © 2019 Society of Chemical Industry.


Assuntos
Diglicerídeos/química , Óleos Vegetais/química , Biocatálise , Emulsificantes/química , Emulsões/química , Lipase/química , Oxirredução , Tamanho da Partícula , Polissorbatos/química , Água/análise , Proteínas do Soro do Leite/química
9.
J Agric Food Chem ; 68(2): 623-632, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31846317

RESUMO

The combined effects of succinic anhydride (SA) succinylation and linear dextrin (LD) glycation on whey protein hydrolysates (WPH) and their stabilized emulsions were evaluated. Degree of succinylation (DS), degree of glycation (DG), and degree of browning of samples suggested that a competitive displacement of reactive groups existed when WPH reacted with SA and LD in different orders. Attenuated total reflection Fourier transform infrared (ATR-FTIR) and far-UV circular dichroism (CD) indicated that the order of modification methods had a significant effect on secondary structures of WPH. Succinylation combined with glycation effectively reduced the surface hydrophobicity and increased the molecular flexibility of WPH. Meanwhile, the total free -SH content decreased, and the exposed free -SH content increased. Results of storage stability and gastrointestinal fate of the curcumin-loaded emulsion revealed that the modified WPH with higher DS was more effective for improving the curcumin bioaccessibility, while that with higher DG was more effective for enhancing the stability of the emulsion.


Assuntos
Curcumina/química , Anidridos Succínicos/química , Proteínas do Soro do Leite/química , Curcumina/metabolismo , Dextrinas/química , Emulsões/química , Trato Gastrointestinal/metabolismo , Glicosilação , Humanos , Interações Hidrofóbicas e Hidrofílicas , Hidrolisados de Proteína/química
10.
J Agric Food Chem ; 68(2): 541-548, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31860295

RESUMO

Besides their nutritional value, whey protein (WP) peptides are food components retaining important pharmacological properties for controlling hypertension. We herein report how the use of complementary experimental and theoretical investigations allowed the identification of novel angiotensin converting enzyme inhibitory (ACEI) peptides obtained from a WP hydrolysate and addressed the rational design of even shorter sequences based on molecular pruning. Thus, after bromelain digestion followed by a 5 kDa cutoff ultrafiltration, WP hydrolysate with ACEI activity was fractioned by RP-HPLC; 2 out of 23 collected fractions retained ACEI activity and were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In the face of 128 identified peptides, molecular docking was carried out to prioritize peptides and to rationally guide the design of novel shorter and bioactive sequences. Therefore, 11 peptides, consisting of 3-6 amino acids and with molecular weights in the range from 399 to 674 Da, were rationally designed and then purchased to determine the IC50 value. This approach allowed the identification of two novel peptides: MHI and IAEK with IC50 ACEI values equal to 11.59 and 25.08 µM, respectively. Interestingly, we also confirmed the well-known ACEI IPAVF with an IC50 equal to 9.09 µM. In light of these results, this integrated approach could pave the way for high-throughput screening and identification of new peptides in dairy products. In addition, the herein proposed ACEI peptides could be exploited for novel applications both for food production and pharmaceuticals.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/química , Peptídeos/química , Proteínas do Soro do Leite/química , Animais , Bovinos , Desenho de Drogas , Humanos , Cinética , Simulação de Acoplamento Molecular , Peso Molecular , Peptidil Dipeptidase A/química , Hidrolisados de Proteína/química
11.
Food Chem ; 311: 125946, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31864183

RESUMO

This study describes an experimental design, based on pH-stat, to rapidly screen and assess food formulation effects on the degrees of hydrolysis (DH) of both proteins and lipids throughout in vitro gastro-intestinal digestions. This approach was used to quantitatively compare and hierarchize key structure parameters of protein emulsions. Six matrices (15 wt% whey proteins, 0 or 10 wt% oil), each differing by at least one structure characteristic, were studied. The physical state of the bulk and the oil droplet size were the major structural levers to modulate the hydrolysis of proteins (final DH between 51.7 and 58.3%) and lipids (final DH between 46.9 and 72.7%), with non-trivial interplays between proteolysis and lipolysis. Additionally, pH-stat measurements in presence of a pancreatic lipase inhibitor proved to be an efficient way to widen the scope of the proposed experimental approach to foods that are intrinsically made of both proteins and lipids.


Assuntos
Trato Gastrointestinal/metabolismo , Proteínas do Soro do Leite/química , Proteínas do Soro do Leite/metabolismo , Digestão , Emulsões/química , Emulsões/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Hidrólise , Lipase/metabolismo , Metabolismo dos Lipídeos , Lipídeos/química , Lipólise , Modelos Biológicos , Proteólise
12.
Food Chem ; 302: 125296, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31400698

RESUMO

The process of manufacturing infant milk formulas (IMFs) involves heat treatments that can lead to whey protein denaturation. The objective of the study was to determine how protein composition affects the denaturation kinetics of the whey proteins within IMFs. Three model IMFs (1.3% of cow's milk protein) were produced with a caseins: whey proteins ratio of 40:60, differing only by the whey protein composition. The kinetics of heat-induced denaturation of α-lactalbumin, ß-lactoglobulin and lactoferrin were investigated between 67.5 °C and 80 °C by chromatographic quantification of the residual native proteins. Results showed that the heat-denaturation of α-lactalbumin was reduced when ß-lactoglobulin was absent. The heat-denaturation of lactoferrin was not affected by the composition of the IMFs but its presence enhanced the heat-denaturation of ß-lactoglobulin. This study revealed that, for higher heat treatments (90 °C/15 s, 75 °C/15 min), IMF containing α-lactalbumin and lactoferrin preserved a higher proportion of native whey proteins than IMFs containing ß-lactoglobulin.


Assuntos
Temperatura Alta , Fórmulas Infantis/química , Desnaturação Proteica , Proteínas do Soro do Leite/química , Animais , Bovinos , Humanos , Lactente , Cinética
13.
Molecules ; 24(20)2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31635143

RESUMO

The search for possible alternatives to traditional flame retardants (FRs) is pushing the academic and industrial communities towards the design of new products that exhibit low environmental impact and toxicity, notwithstanding high performances, when put in contact with a flame or exposed to an irradiative heat flux. In this context, in the last five to ten years, the suitability and effectiveness of some biomacromolecules and bio-sourced products with a specific chemical structure and composition as effective flame retardants for natural or synthetic textiles has been thoroughly explored at the lab-scale level. In particular, different proteins (such as whey proteins, caseins, and hydrophobins), nucleic acids and extracts from natural sources, even wastes and crops, have been selected and exploited for designing flame retardant finishing treatments for several fibers and fabrics. It was found that these biomacromolecules and bio-sourced products, which usually bear key elements (i.e., nitrogen, phosphorus, and sulphur) can be easily applied to textiles using standard impregnation/exhaustion methods or even the layer-by-layer technique; moreover, these "green" products are mostly responsible for the formation of a stable protective char (i.e., a carbonaceous residue), as a result of the exposure of the textile substrate to a heat flux or a flame. This review is aimed at summarizing the development and the recent progress concerning the utilization of biomacromolecules/bio-sourced products as effective flame retardants for different textile materials. Furthermore, the existing drawbacks and limitations of the proposed finishing approaches as well as some possible further advances will be considered.


Assuntos
Fibra de Algodão , Retardadores de Chama , Temperatura Alta , Proteínas do Soro do Leite/química
14.
Molecules ; 24(18)2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31500127

RESUMO

Various bioactive compounds (BCs) often possess poor stability and bioavailability, which makes it difficult for them to exert their potential health benefits. These limitations can be countered by the use of nano-delivery systems (NDSs), such as nanoparticles and nanoemulsions. NDSs can protect BCs against harsh environments during food processing and digestion, and thereby, could enhance the bioavailability of BCs. Although various NDSs have been successfully produced with both synthetic and natural materials, it is necessary to fulfill safety criteria in the delivery materials for food applications. Food-grade materials for the production of NDSs, such as milk proteins and carbohydrates, have received much attention due to their low toxicity, biodegradability, and biocompatibility. Among these, whey proteins-from whey, a byproduct of cheese manufacturing-have been considered as excellent delivery material because of their high nutritional value and various functional properties, such as binding capability to various compounds, gelation, emulsifying properties, and barrier effects. Since the functional and physicochemical properties of whey protein-based NDSs, including size and surface charge, can be key factors affecting the applications of NDSs in food, the objectives of this review are to discuss how manufacturing variables can modulate the functional and physicochemical properties of NDSs and bioavailability of encapsulated BCs to produce efficient NDSs for various BCs.


Assuntos
Sistemas de Liberação de Medicamentos , Proteínas do Leite/química , Nanopartículas/química , Proteínas do Soro do Leite/química , Disponibilidade Biológica , Emulsões/química , Emulsões/uso terapêutico , Manipulação de Alimentos , Géis/química , Humanos , Proteínas do Leite/uso terapêutico , Tamanho da Partícula , Proteínas do Soro do Leite/uso terapêutico
15.
Food Funct ; 10(9): 6074-6087, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31490476

RESUMO

Buffering capacity is a characteristic of foods to resist changes in pH, which is important to consider in gastric digestion as it will impact physicochemical breakdown of food. A standardized method to measure and quantify buffering capacity in the context of digestion is needed to improve in vitro digestion studies by providing a better estimation of acid secretions and subsequent protein digestibility. The objective of this study was to develop a method to measure buffering capacity in the context of digestion and develop a regression model to predict buffering capacity using protein-based model foods. Buffering capacity was analyzed by titrating 0.16 M HCl to egg and whey-protein based dispersions and gels of varying protein content and particle size and recording the pH after each addition. Calculated parameters from buffering capacity experiments included total acid added, area under the curve, total buffering capacity, relative [H+] increase, and lag phase. A regression model was developed to predict each buffering capacity parameter based on protein concentration, specific surface area, aspartic acid and glutamic acid content. Results showed that higher protein concentration and smaller surface area resulted in higher buffering capacity. A validation dataset was used to evaluate the goodness of fit of the model to the data with different protein concentrations, surface area or protein source. Results indicated that total buffering capacity and lag phase parameters can be used to quantify buffering capacity of protein gels in the context of digestion, since they provided a good fit to the observational and validation data sets.


Assuntos
Proteínas do Ovo/química , Estômago/química , Proteínas do Soro do Leite/química , Animais , Tampões (Química) , Bovinos , Galinhas , Digestão , Proteínas do Ovo/metabolismo , Mucosa Gástrica/metabolismo , Concentração de Íons de Hidrogênio , Modelos Biológicos , Proteínas do Soro do Leite/metabolismo
16.
J Dairy Sci ; 102(12): 10855-10866, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31548058

RESUMO

In recent years, using dairy phospholipids (PL) as functional ingredients has increased because PL have nutritional benefits and functional properties. In this study, a novel 2-step supercritical fluid extraction (SFE) process was used to extract whey protein phospholipid concentrate (WPPC), a dairy co-product obtained during the manufacture of whey protein isolate, for PL enrichment. In the first step, nonpolar lipids in WPPC were removed using neat supercritical carbon dioxide (S-CO2) at 41.4 MPa and 60°C. In the second stage, the feasibility of using the polar solvent ethanol as a co-solvent to increase the solubility of S-CO2 extraction solvent was explored. A 3 × 3 × 2 factorial design with extraction pressure (35.0, 41.4, and 55.0 MPa), temperature (40 and 60°C), and concentration of ethanol (10, 15, and 20%) as independent factors was used to evaluate the extraction efficiency providing the most total PL, and the best proportion of each individual PL from the spent solids collected during S-CO2 SFE. All lipid fractions were analyzed using thin-layer chromatography and high-performance lipid chromatography. The total amount of PL extracted from WPPC was significantly affected by ethanol concentration; the extraction pressure and temperature were nonsignificant. The optimal SFE condition for generating a concentrated PL lipid fraction was 35.0 MPa, 40°C, and 15% ethanol concentration; the highest amount of extracted PL averaged 26.26 g/100 g of fat. Moreover, adjusting SFE condition allowed successful recovery of a high concentration of sphingomyelin, phosphatidylcholine, and phosphatidylethanolamine, giving averages of 11.07, 10.07, and 7.2 g/100 g of fat, respectively, 2 to 3 times more than conventional solvent extraction. In addition, exhausted solids obtained after the SFE process were enriched with denatured proteins (72% on dry basis) with significantly more water-holding capacity and emulsifying capacity than untreated WPPC. Overall, this 2-stage SFE process using neat S-CO2 and ethanol has the greatest potential to produce a PL-rich lipid fraction from WPPC.


Assuntos
Cromatografia com Fluido Supercrítico/métodos , Fosfolipídeos/isolamento & purificação , Proteínas do Soro do Leite/química , Dióxido de Carbono/química , Cromatografia em Camada Delgada , Etanol/química , Fosfolipídeos/química , Solubilidade , Solventes/química , Temperatura Ambiente
17.
Molecules ; 24(18)2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31510031

RESUMO

Enzymatic hydrolysis of lactose is a crucial step to improve the efficiency and selectivity of membrane-based separations toward the recovery of milk oligosaccharides free from simple sugars. Response surface methodology was used to investigate the effects temperature (25.9 to 54.1 °C) and amount of enzyme (0.17 to 0.32% w/w) at 1, 2, and 4 h of reaction on the efficiency of lactose hydrolysis by Aspergillus oryzae ß-galactosidase, preservation of major goat whey oligosaccharides, and on the de-novo formation of oligosaccharides. Lactose hydrolysis above 99% was achieved at 1, 2, and 4 h, not being significantly affected by temperature and amount of enzyme within the tested conditions. Formation of 4 Hexose (Hex) and 4 Hex 1 Hex and an increased de-novo formation of 2 Hex 1 N-Acetyl-Neuraminic Acid (NeuAc) and 2 Hex 1 N-Glycolylneuraminic acid (NeuGc) was observed in all treatments. Overall, processing conditions using temperatures ≤40 °C and enzyme concentration ≤0.25% resulted in higher preservation/formation of goat whey oligosaccharides.


Assuntos
Lactose/química , Oligossacarídeos/química , Proteínas do Soro do Leite/química , beta-Galactosidase/química , Animais , Aspergillus oryzae/enzimologia , Cabras , Hexoses/química , Concentração de Íons de Hidrogênio , Hidrólise , Leite/química , Modelos Químicos , Ácidos Neuramínicos/química , Temperatura Ambiente , Soro do Leite/química
18.
Int J Mol Sci ; 20(16)2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31408980

RESUMO

3,3'-Diindolylmethane (DIM) is a bioactive compound found in Cruciferous vegetables that possesses health benefits such as antioxidant, anticancer, and anti-inflammatory effects. However, hydrophobicity and photolabile limit its pharmaceutical applications. This study aims to prepare and characterize DIM-encapsulated whey protein isolate (WPI) nanoparticles mixed at different ratios of WPI and DIM using the combined heating-ultrasound method. Results showed that all the samples showed adequate physicochemical characteristics: The mean particle size of the nanoparticles could be controlled down to 96-157 nm depending on the DIM to WPI ratio used in the preparation with a low polydispersity index (<0.5), higher negative values of zeta potential (>-40 mV) as well as with greater encapsulation efficiency (>82%). Flow behavior indices showed the shear-thinning Non-Newtonian or pseudoplastic (n < 1) behavior of the nanoparticles. The thermal properties were characterized by differential scanning calorimetry (DSC), which showed that DIM was successfully entrapped in WPI nanoparticles. The secondary structure of WPI was changed after DIM incorporation; electrostatic interaction and hydrogen bonding were major facilitating forces for nanoparticles formation, confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). Transmission electron microscopy (TEM) micrographs showed that all the samples had a smooth surface and spherical structure. The wall material (WPI) and encapsulation method provide effective protection to DIM against UV light and a broad range of physiologically relevant pH's (2.5, 3.5, 4.5, 5.5, and 7). In conclusion, whey protein isolate (WPI)-based nanoparticles are a promising approach to encapsulate DIM and overcome its physicochemical limitations with improved stability.


Assuntos
Anticarcinógenos/administração & dosagem , Indóis/administração & dosagem , Nanocápsulas/química , Proteínas do Soro do Leite/química , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/química , Anticarcinógenos/química , Antioxidantes/administração & dosagem , Antioxidantes/química , Brassicaceae/química , Composição de Medicamentos , Estabilidade de Medicamentos , Indóis/química , Nanocápsulas/ultraestrutura , Espectroscopia de Infravermelho com Transformada de Fourier
19.
Int J Mol Sci ; 20(17)2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438619

RESUMO

Whey protein and inulin at various weight ratios were dry heated at 60 °C for 5 days under relative humidity of 63%. The heated mixtures were found to have significant changes in browning intensity and zeta-potential compared to untreated mixture. Heated samples showed significantly lower surface hydrophobicity than untreated mixtures. Compared with untreated samples, dry-heated samples showed significantly higher 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) scavenging ability with whey protein to inulin mass ratios of 1:2 and 1:3 and significantly higher 2,2'-Azinobis(2-Ethylbenzothiazoline-6-Sulfonate) (ABTS) scavenging abilities and oxygen radical absorbance capacity (ORAC) at all weight ratios. Dry heat-induced interactions between whey protein and inulin was confirmed by changes in Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS-PAGE) protein profile, Fourier Transform Infrared Spectroscopy (FT-IR) and Far-ultraviolet Circular Dichroism (Far-UV CD) spectra. Dry heating caused physicochemical and structural changes of whey protein and therefore the complexes can be used to improve the antioxidative properties of the mixture under certain conditions.


Assuntos
Antioxidantes/química , Inulina/química , Proteínas do Soro do Leite/química , Dicroísmo Circular , Eletroforese em Gel de Poliacrilamida , Espectroscopia de Infravermelho com Transformada de Fourier
20.
Ultrason Sonochem ; 58: 104678, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31450348

RESUMO

This study investigated the effect of glycation on the binding of whey protein isolate (WPI) with (-)-epigallocatechin-3-gallate (EGCG), and the physicochemical stability and bioaccessibility of the formed complex. The WPI-gum Acacia (GA) conjugate was prepared by ultrasound-assisted Maillard reaction. Results indicated that conjugated WPI showed stronger binding and entrapping ability to EGCG than that of WPI. The protein aggregation induced by EGCG was partly inhibited by glycosylation, presumably due to the steric hindrance of polysaccharide chains. The greatest protection of EGCG and its antioxidant activity were also obtained by complexing it with WPI-GA conjugate. The in vitro bioaccessibility analysis demonstrated that the bioaccessibility of EGCG cloud be significantly (p < 0.05) enhanced by complexing it with WPI, especially WPI-GA conjugate. These findings are important to design promising and effective EGCG carriers for its wide application in food industry.


Assuntos
Catequina/análogos & derivados , Reação de Maillard , Ondas Ultrassônicas , Proteínas do Soro do Leite/química , Catequina/química , Glicosilação , Interações Hidrofóbicas e Hidrofílicas
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