Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 33
Filtrar
1.
J Dairy Sci ; 106(8): 5242-5252, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37291035

RESUMO

Gastric digestion of 2 commercial ultrafiltered milks and milk enriched with skim milk powder (to simulate concentration by reverse osmosis) was investigated and compared with the digestion of nonconcentrated milk. Curd formation and proteolysis of high-protein milks in simulated gastric conditions were studied using oscillatory rheology, extrusion testing, and gel electrophoresis. The presence of pepsin in the gastric fluid triggered coagulation at pH >6 and the elastic modulus of gels from high-protein milks was ~5 times larger than the gel from reference milk. Despite similar protein concentrations, the coagulum from milk enriched with skim milk powder showed higher resistance to shear deformation than the coagula from ultrafiltered milks. The gel structure was also more heterogeneous. During digestion, the degradation of coagula from high-protein milks was slowed down compared with the coagulum from reference milk, and intact milk proteins were still detected after 120 min. Differences in the digestion patterns of coagula from high-protein milks were observed and were associated with the proportion of minerals bound to caseins and the denaturation rate of whey proteins.


Assuntos
Proteínas do Leite , Leite , Animais , Proteólise , Pós/análise , Leite/química , Proteínas do Leite/análise , Proteínas do Soro do Leite/análise , Caseínas/química , Reologia , Concentração de Íons de Hidrogênio
2.
Int J Vitam Nutr Res ; 91(5-6): 461-468, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32138619

RESUMO

Dairy beverages containing emulsified linseed oil is a suitable vehicle for delivering polyunsaturated fatty acids to consumers. However, these beverages are prone to oxidation. The purpose of this study was to evaluate the effect of adding various concentrations (0, 0.001, 0.01 and 0.1% (w/w)) of green tea extract (GTE) to dairy beverages (DB) containing linseed oil (2.0%, w/w), in order to inhibit lipid oxidation during storage at high temperature (50 °C) or under fluorescent light exposure. During storage, the concentration of catechin (C), epicatechin (EC) and epicatechin gallate (ECG) were significantly reduced (P ≤ 0.05) and degradation rate was greater when the DB were exposed to light (C 35%, EC 74% and ECG 68%) as compared to high temperature (C 34%, EC 45% and ECG 49%). In DB without GTE, the conjugated dienes (CD) hydroperoxides concentration increased significantly (P ≤ 0.05) from 23 mmol kg-1 fat to 243 mmol kg-1 fat under 6-day-light exposition, and to 83 mmol kg-1 fat under 6-day-heat temperature. The addition of GTE significantly increased the antioxidant capacity of DB and reduced the formation of CD, propanal and hexanal, induced by light exposure or high temperature. GTE at 0.10% completely inhibited CD formation during the storage period and reduced propanal and hexanal concentrations below the threshold.


Assuntos
Catequina , Bebidas , Óleo de Semente do Linho , Extratos Vegetais , Chá
3.
J Dairy Sci ; 100(4): 2454-2470, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28189318

RESUMO

Calcium plays an important role in intestinal lipid digestion by increasing the lipolysis rate, but also limits fatty acid bioaccessibility by producing insoluble Ca soaps with long-chain fatty acids at intestinal pH conditions. The aim of this study was to better understand the effect of Ca on the bioaccessibility of milk fat from Cheddar-type cheeses. Three anhydrous milk fats (AMF) with different fatty acid profiles (olein, stearin, or control AMF) were used to prepare Cheddar-type cheeses, which were then enriched or not with Ca using CaCl2 during the salting step. The cheeses were digested in vitro, and their disintegration and lipolysis rates were monitored during the process. At the end of digestion, lipids were extracted under neutral and acidic pH conditions to compare free fatty acids under intestinal conditions in relation to total fatty acids released during the digestion process. The cheeses prepared with the stearin (the AMF with the highest ratio of long-chain fatty acids) were more resistant to disintegration than the other cheeses, owing to the high melting temperature of that AMF. The Ca-enriched cheeses had faster lipolysis rates than the regular Ca cheeses. Chromatographic analysis of the digestion products showed that Ca interacted with long-chain fatty acids, producing Ca soaps, whereas no interaction with shorter fatty acids was detected. Although higher Ca levels resulted in faster lipolysis rates, driven by the depletion of reaction products as Ca soaps, such insoluble compounds are expected to reduce the bioavailability of fatty acids by hindering their absorption. These effects on lipid digestion and absorption are of interest for the design of food matrices for the controlled release of fat-soluble nutrients or bioactive molecules.


Assuntos
Cálcio , Queijo , Animais , Cálcio/farmacocinética , Cálcio da Dieta , Digestão , Ácidos Graxos/farmacocinética , Manipulação de Alimentos , Leite/química
4.
J Dairy Sci ; 100(7): 5139-5152, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28456400

RESUMO

The objectives of this study were (1) to assess the effect of a denatured whey protein concentrate (DWPC) and its fractions on cheese yield, composition, and rheological properties, and (2) to separate the direct effect of the DWPC or its fractions on cheese rheological properties from the effect of a concomitant increase in cheese moisture. Semihard cheeses were produced at a laboratory scale, and mechanical properties were characterized by dynamic rheometry. Centrifugation was used to induce a moisture gradient in cheese to separate the direct contribution of the DWPC from the contribution of moisture to cheese mechanical properties. Cheese yield increased and complex modulus (G*) decreased when the DWPC was substituted for milk proteins in milk. For cheeses with the same moisture content, the substitution of denatured whey proteins for milk proteins had no direct effect on rheological parameters. The DWPC was fractionated to evaluate the contribution of its different components (sedimentable aggregates, soluble component, and diffusible component) to cheese yield, composition, and rheological properties. The sedimentable aggregates were primarily responsible for the increase in cheese yield when DWPC was added. Overall, moisture content explained to a large extent the variation in cheese rheological properties depending on the DWPC fraction. However, when the effect of moisture was removed, the addition of the DWPC sedimentable fraction to milk increased cheese complex modulus. Whey protein aggregates were hypothesized to act as active fillers that physically interact with the casein matrix and confer rigidity after pressing.


Assuntos
Queijo/análise , Manipulação de Alimentos/métodos , Leite/química , Reologia , Proteínas do Soro do Leite/química , Animais , Caseínas , Tecnologia de Alimentos , Proteínas do Leite , Desnaturação Proteica
5.
J Food Sci Technol ; 54(6): 1608-1615, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28559620

RESUMO

In this study, yogurt was supplemented with 1.5 and 3.0 g L-1 of grape extract, inoculated culture containing Streptococcus thermophilus, Lactobacillus bulgaricus, Lactobacillus acidophilus and Bifidobacterium bb12 bifidum, fermented and stored at 4 °C. Acid production, microbial growth, gel strength, syneresis, rheological and sensory properties were studied. An increase in grape extract concentration extended fermentation time. Bacterial strains were found in at least 109 CFU100 g-1 of yogurt showing the possibility of probiotic yogurt production with grape extract. Gel strength decreased with increasing concentration of grape extract while syneresis increased. The addition of grape extract changed the dilatant behavior to a pseudoplastic behavior, decreased yield stress, whereas k values increased. Sensory attributes (color, flavor, taste, texture and appearance) didn't differ significantly.

6.
J Dairy Res ; 83(4): 497-504, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27845023

RESUMO

Antibiotics are commonly used in poultry feed as growth promoters. This practice is questioned given the arising importance of antibiotic resistance. Antimicrobial peptides can be used as food additives for a potent alternative to synthetic or semi-synthetic antibiotics. The objective of this study was to develop a peptide production method based on membrane adsorption chromatography in order to produce extracts with antimicrobial activity against avian pathogens (Salmonella enterica var. Enteritidis, Salmonella enterica var. Typhimurium, and two Escherichia coli strains, O78:H80 and TK3 O1:K1) as well as Staphylococcus aureus. To achieve this, buttermilk powder and purified lactoferrin were digested with pepsin. The peptide extracts (<10 kDa) were fractionated depending on their charges through high-capacity cation-exchange and anion-exchange adsorptive membranes. The yields of cationic peptide extracts were 6·3 and 15·4% from buttermilk and lactoferrin total peptide extracts, respectively. Antimicrobial activity was assessed using the microdilution technique on microplates. Our results indicate that the buttermilk cationic peptide extracts were bactericidal at less than 5 mg/ml against the selected avian strains, with losses of 1·7 log CFU/ml (Salm. Typhimurium) to 3 log CFU/ml (E. coli O78:H80); viability decreased by 1·5 log CFU/ml for Staph. aureus, a Gram-positive bacterium. Anionic and non-adsorbed peptide extracts were inactive at 5 mg/ml. These results demonstrate that membrane adsorption chromatography is an effective way to prepare a cationic peptide extract from buttermilk that is active against avian pathogens.


Assuntos
Anti-Infecciosos/farmacologia , Leitelho/análise , Lactoferrina/química , Peptídeos/farmacologia , Doenças das Aves Domésticas/microbiologia , Aves Domésticas/microbiologia , Animais , Escherichia coli/efeitos dos fármacos , Lactoferrina/metabolismo , Pepsina A/metabolismo , Peptídeos/isolamento & purificação , Salmonella enterica/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
7.
Int J Food Sci Nutr ; 67(3): 298-304, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26960683

RESUMO

Interactions between ß-lactoglobulin (ß-lg) and epigallocatechin-3-gallate (EGCG) may modulate their health benefits. The objective of this study was therefore to investigate the synergistic effect of consuming ß-lg and EGCG complexes on glucose tolerance of C57BL/6 male mice given an oral glucose tolerance test (OGTT) and randomized to one of the following treatments administered prior to the OGTT: 1) simulated milk ultrafiltrate (SMUF(-)), 2) SMUF(-) + EGCG, 3) SMUF(-) + ß-lg, 4) SMUF(-) + EGCG + ß-lg, 5) SMUF + calcium (SMUF(+)) and 6) SMUF(+) + EGCG + ß-lg. We found no significant between-group difference in postprandial glucose response. However, when mice were separated in those who received ß-lg from those who did not, we found that the latter displayed significantly higher postprandial glucose concentrations. Our results support the beneficial impact of ß-lg on glycemic control and suggest that concomitant EGCG or calcium consumption does not improve this effect.


Assuntos
Cálcio/farmacologia , Catequina/análogos & derivados , Intolerância à Glucose/prevenção & controle , Glucose/administração & dosagem , Lactoglobulinas/farmacologia , Animais , Glicemia , Cálcio/administração & dosagem , Catequina/administração & dosagem , Catequina/farmacologia , Glucose/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Distribuição Aleatória
8.
J Dairy Sci ; 98(3): 1552-62, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25597978

RESUMO

Grape extracts can be added to milk to produce cheese with a high concentration of polyphenols. Four commercial extracts from whole grape, grape seed, and grape skin (2 extracts) were characterized and added to milk at concentrations of 0, 0.1, 0.2, and 0.3% (wt/vol). The effect of grape extracts on the kinetics of milk clotting, milk gel texture, and syneresis were determined, and model cheeses were produced. Whole grape and grape seed extracts contained a similar concentration of polyphenolic compounds and about twice the amount found in grape skin extracts. Radical scavenging activity was directly proportional to the phenolic compounds content. When added to milk, grape extracts increased rennet-induced clotting time and decreased the clotting rate. Although differences were observed between the extracts, the concentration added to milk was the main factor influencing clotting properties. With increasing concentrations of grape extracts, milk gels showed increased brittleness and reduced firmness. In addition, syneresis of milk gels decreased with increasing concentrations of grape extracts, which resulted in cheeses with a higher moisture content. The presence of grape extracts in milk slightly increased protein recovery in cheese but had no effect on fat recovery. With whole grape or grape seed extracts added to milk at 0.1% (wt/vol), the recovery coefficient for polyphenols was about 0.63, and decreased with increasing extract concentration in milk. Better polyphenol recovery was observed for grape seed extracts (0.87), with no concentration effect. Commercial extracts from whole grape, grape seed, or grape skin can be added to milk in the 0.1 to 0.3% (wt/vol) concentration range to produce cheese with potential health benefits, without a negative effect on cheese yield.


Assuntos
Queijo/análise , Manipulação de Alimentos/métodos , Leite/química , Extratos Vegetais/química , Vitis/química , Animais , Quimosina/química , Géis/química , Concentração de Íons de Hidrogênio , Proteínas do Leite/química , Polifenóis/química
9.
J Dairy Res ; 78(1): 111-7, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21214967

RESUMO

Nutritional value is a priority in new product development. Using vegetable or marine oils, rich in polyunsaturated fatty acids, in dairy beverage formulations is an option to provide the consumers with healthier products. However, these formulations are prone to oxidation, which is responsible for rapid flavour degradation and the development of potentially toxic reaction products during storage. Flaxseed lignans, secoisolariciresinol diglucoside (SDG), and its mammalian metabolites have antioxidant activity and could be used in beverage formulations to prevent oxidation. Commercially available SDG extract was added to the formulation of dairy beverages enriched with flaxseed oil. As an alternative approach, dairy beverages were produced from milk naturally rich in SDG metabolites obtained through the alteration of cow diet. Resistance to oxidation was determined from the kinetics of hexanal and propanal production during heat and light exposure treatments. Increasing SDG concentration in dairy beverage slightly reduced redox potential but had no effect on oxygen consumption during oxidation treatments. The presence of SDG in dairy beverage significantly improved resistance to heat- and light-induced oxidation. However, purified enterolactone, a mammalian metabolite from SDG, prevented oxidation at much lower concentrations. The use of milk from dairy cow fed flaxseed meal did not improve resistance to oxidation in dairy beverage. Enterolactone concentration in milk was increased by the experimental diet but it remained too low to observe any significant effect on dairy beverage oxidation.


Assuntos
Antioxidantes/administração & dosagem , Ácidos Graxos Insaturados/química , Linho/química , Alimentos Fortificados , Lignanas/administração & dosagem , Leite/química , 4-Butirolactona/análogos & derivados , 4-Butirolactona/análise , 4-Butirolactona/metabolismo , 4-Butirolactona/farmacologia , Animais , Butileno Glicóis/administração & dosagem , Butileno Glicóis/metabolismo , Bovinos , Dieta , Feminino , Glucosídeos/administração & dosagem , Glucosídeos/metabolismo , Temperatura Alta , Lignanas/análise , Lignanas/metabolismo , Lignanas/farmacologia , Oxirredução , Estresse Oxidativo , Processos Fotoquímicos
10.
J Microencapsul ; 28(5): 337-43, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21736518

RESUMO

Aroma-loaded nanoparticles (d < 300 nm) were prepared by cross-linking denatured whey protein through pH-cycling. The effect of nanoparticulation conditions and aroma concentration on the physicochemical characteristics of nanoparticles and aroma release profile was studied. Better retention of aroma was observed when ethyl hexanoate was added before nanoparticle formation. The highest aroma retention was obtained for nanoparticles produced at pH 5.0 and 5.5 without calcium addition. These nanoparticles are characterized by a less compact and more porous internal structure allowing a higher loading of aroma. Increasing aroma concentration increased the diameter and the voluminosity of the aroma-loaded nanoparticles. The percentage of aroma retention showed an increase from 7% to 24% over the tested concentration range while the value averaged 2% for native or denatured whey protein. Encapsulation of ethyl hexanoate in whey protein nanoparticles reduced the mass transfer of aroma at the surface of the matrix and improved its retention.


Assuntos
Aromaterapia , Proteínas do Leite/administração & dosagem , Nanopartículas/química , Caproatos , Cápsulas , Humanos , Interações Hidrofóbicas e Hidrofílicas , Nanopartículas/uso terapêutico , Proteínas do Soro do Leite
11.
Food Funct ; 11(11): 10126-10136, 2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33150352

RESUMO

Health benefits have been associated with the consumption of omega-3 polyunsaturated fatty acids (PUFA). Linseed oil is rich in long chain omega-3 PUFA, but can generate toxic compounds due to its high susceptibility to oxidation. The nature of the emulsifier can affect both lipolysis and oxidation during digestion since these phenomena occur at the oil-water interface. The objective of this study was to compare the effect of low-molecular weight surfactants (cetyltrimethylammonium bromide (CTAB), Citrem), protein (sodium caseinate, fish gelatin) and polysaccharides (gum arabic, modified starch) on the structure of linseed oil emulsions, lipolysis and formation of reactive oxidation species during in vitro digestion. The emulsion stabilized with Citrem underwent extensive coalescence in the gastric phase, which strongly decreased the extent of lipid digestion and reduced the formation of oxidation markers relative to other emulsions. Emulsions stabilized by proteins and modified starch showed aggregation with partial coalescence in the gastric phase, but protein-stabilized emulsions showed better resistance to oxidation. This study shows that emulsifier properties affect the susceptibility of the emulsion to aggregation and coalescence in the gastrointestinal environment, and strongly influence the extent of lipid digestion and the formation of reactive oxidation products. These findings point out the importance of the choice of the emulsifier to control the lipid digestibility and the protection of sensible lipids thus promoting optimal nutritional properties in omega-3-enriched foods.


Assuntos
Emulsificantes/química , Óleo de Semente do Linho/química , Caseínas/química , Caseínas/metabolismo , Digestão , Emulsificantes/metabolismo , Humanos , Óleo de Semente do Linho/metabolismo , Lipólise , Modelos Biológicos , Oxirredução , Polissacarídeos/química , Polissacarídeos/metabolismo
12.
Food Chem ; 294: 130-137, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31126445

RESUMO

Health benefits are associated with polyunsaturated fatty acids, but their sensitivity to oxidation may generate toxic oxidation species. The objective of this study was to compare the effect of milk proteins (casein, whey protein) and surfactants (Citrem, Tween 20) on the in vitro digestion and oxidation of linseed oil emulsions. The emulsion produced with Tween 20 resisted coalescence in the gastric phase and showed the highest concentrations of free fatty acids and reactive carbonyl compounds in the intestinal digestion phase. The Citrem-stabilized emulsion showed extensive coalescence in the gastric environment, which reduced lipolysis and the formation of advanced oxidation species. The protein-stabilized emulsions showed aggregation with some coalescence in the gastric phase, and casein provided better protection than whey protein against oxidation. This study suggests that the mechanism of emulsion destabilization in the gastric environment and the type of protein can modulate lipolysis and oxidation during in vitro digestion.


Assuntos
Emulsões/química , Óleo de Semente do Linho/química , Proteínas do Leite/metabolismo , Tensoativos/química , Água/química , Antioxidantes/química , Ácidos Graxos não Esterificados/análise , Ácidos Graxos não Esterificados/metabolismo , Lipólise , Microscopia , Proteínas do Leite/química , Oxirredução , Proteólise
13.
Food Res Int ; 122: 149-156, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31229066

RESUMO

Polyunsaturated fatty acids (PUFA) are associated with health benefits. However, high PUFA intake increases the risk of lipid oxidation and formation of potentially toxic lipid oxidation species. The objective of this study was to determine the antioxidant activity of milk fractions (whole milk, skim milk, acid whey, ultrafiltration (UF) permeate) and polyphenol-rich beverages (green tea, grape juice) during simulated gastrointestinal digestion. We also determined the effect of milk and polyphenol-rich beverages on the formation of advanced oxidation species during in vitro digestion of PUFA-rich emulsion. Antioxidant activity during digestion of milk fractions emphasized the important role of proteins (more specifically caseins) and the contribution of fat to the antioxidant capacity of milk. In comparison to milk, the antioxidant activity of polyphenol-rich beverages was at least four times higher. During digestion of a PUFA-rich emulsion, the formation of 4-hydroxyhexanal (4-HHE) and 4-hydroxynonenal (4-HNE) in the intestinal phase were respectively reduced by 60% and 75%, in the presence of milk or polyphenol-rich beverages. Further reduction was observed when the emulsion was co-digested with both, milk and polyphenol-rich beverages (89% for 4-HHE and 93% for 4-HNE). These results suggest that the combination of milk and polyphenol-rich beverages increases the antioxidant activity and synergistically reduces the formation of toxic lipid oxidation species during simulated digestion of PUFA-rich foods.


Assuntos
Antioxidantes/metabolismo , Digestão/fisiologia , Óleo de Semente do Linho/metabolismo , Leite/metabolismo , Modelos Biológicos , Aldeídos/análise , Aldeídos/metabolismo , Animais , Emulsões , Polifenóis/metabolismo
14.
Food Res Int ; 118: 65-71, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30898354

RESUMO

The aim of this study was to better understand the effect of calcium on the bioavailability of milk lipids from a cheese matrix using a rat model. Cheddar-type cheeses were manufactured with one of three types of anhydrous milk fat, control, olein or stearin, and salted with or without CaCl2. The cheeses were fed to rats and postprandial lipemia was monitored. Feces were analyzed to quantify fatty acids excreted as calcium soaps. Higher calcium concentration in cheese caused a higher and faster triacylglycerol peak in blood, except for cheeses containing stearin. Furthermore, calcium soaps were more abundant in feces when the ingested cheese had been enriched with calcium and when the cheese was prepared with stearin. Increased lipid excretion was attributable to the affinity of saturated long-chain fatty acids for calcium. Results showed that lipid bioaccessibility can be regulated by calcium present in Cheddar cheese. This study highlights the nutritional interaction between calcium and lipids present in the dairy matrix and confirms its physiological repercussions on fatty acid bioavailability.

15.
Food Res Int ; 121: 269-277, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31108748

RESUMO

Cheese characteristics, such as composition or textural properties, can impact the matrix degradation rate which could modulate the bioaccessibility of fatty acids during digestion. The aim of this study was to identify texture parameters influencing cheese degradation in a gastrointestinal environment. A static in vitro digestion model has been used on nine commercial cheeses: young and aged cheddar, regular and light cream cheese, parmesan, feta, camembert, mozzarella, and sliced processed cheese. At the end of gastric digestion, camembert and mozzarella presented the lowest matrix disintegration whereas aged cheddar, regular and light cream cheeses showed the highest. For all cheeses, the fatty acid release was fast during the first 30 min of duodenal digestion and slowed down afterwards. A partial least square regression revealed that springiness, cohesiveness, and hardness were negatively correlated to the rate of cheese disintegration during gastric digestion. In addition, textural parameters were not correlated with free fatty acid release. By modulating cheese texture, it could be possible to influence matrix disintegration during gastrointestinal digestion which could have an impact on lipids release.


Assuntos
Queijo/análise , Digestão/fisiologia , Ácidos Graxos , Modelos Biológicos , Queijo/classificação , Ácidos Graxos/análise , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Tecnologia de Alimentos , Humanos , Lipólise
16.
Food Chem ; 275: 193-196, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30724187

RESUMO

Fractionation of ß-lactoglubulin (ß-lg) and α-lactalbumin (α-la) using conventional separation technologies remains challenging mainly due to similar molecular weight. Herein, casein (CN) was used as ligand protein to specifically aggregate ß-lg under high hydrostatic pressure (HHP) in order to separate α-la after acidification to pH 4.6. Specifically, we studied the effect of different concentration of CN on α-la purity and recovery. Model solutions of α-la, ß-lg and CN (from 0 to 5 mg/mL) were pressurized (600 MPa-5 min). After acidification and centrifugation of pressure-treated solutions, purity of α-la was increased up to 78% with a recovery of 88% for solution without CN. In contrast with our initial hypothesis, the presence of CN decreased ß-lg pressure-induced aggregation and co-precipitation upon acidification and significantly reduced purity (∼71%). Therefore, our results suggest a chaperone-like activity of CN on ß-lg pressure-induced aggregation which needs further investigation.


Assuntos
Caseínas/metabolismo , Lactalbumina/isolamento & purificação , Lactoglobulinas/química , Caseínas/química , Centrifugação , Fracionamento Químico/métodos , Pressão Hidrostática , Lactalbumina/química , Lactalbumina/metabolismo , Pressão
17.
Foods ; 8(6)2019 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-31181741

RESUMO

Ultrafiltration (UF) and microfiltration (MF) are widely-used technologies to standardize the protein content of cheesemilk. Our previous work demonstrated that protein retention of a 0.1-µm MF spiral-wound membrane (SWM) was lower, but close to that of a 10 kDa UF one. Considering that the permeability of MF membranes is expected to be higher than that of UF ones, it was hypothesized that the former could improve the efficiency of the cheesemaking process. Consequently, the objectives of this work were to compare 0.1-µm MF and 10 kDa UF spiral-wound membranes in terms of (1) hydraulic and separation performance, (2) energy consumption and fouling behavior, (3) cheesemaking efficiency of retentates enriched with cream, and (4) economic performance in virtual cheesemaking plants. This study confirmed the benefits of using MF spiral-wound membranes to reduce the specific energy consumption of the filtration process (lower hydraulic resistance and higher membrane permeability) and to enhance the technological performance of the cheesemaking process (higher vat yield, and protein and fat recoveries). However, considering the higher serum protein retention of the UF membrane and the low price of electricity in Canada, the UF scenario remained more profitable. It only becomes more efficient to substitute the 10 kDa UF SWM by the 0.1-µm MF when energy costs are substantially higher.

18.
Food Res Int ; 107: 589-595, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29580523

RESUMO

The aim of this study was to better understand the effect of calcium on the bioavailability of milk lipids from a cheese matrix using a rat model. Cheddar-type cheeses were manufactured with one of three types of anhydrous milk fat, control, olein or stearin, and salted with or without CaCl2. The cheeses were fed to rats and postprandial lipemia was monitored. Feces were analyzed to quantify fatty acids excreted as calcium soaps. Higher calcium concentration in cheese caused a higher and faster triacylglycerol peak in blood, except for cheeses containing stearin. Furthermore, calcium soaps were more abundant in feces when the ingested cheese had been enriched with calcium and when the cheese was prepared with stearin. Increased lipid excretion was attributable to the affinity of saturated long-chain fatty acids for calcium. Results showed that lipid bioaccessibility can be regulated by calcium present in Cheddar cheese. This study highlights the nutritional interaction between calcium and lipids present in the dairy matrix and confirms its physiological repercussions on fatty acid bioavailability.


Assuntos
Cloreto de Cálcio/metabolismo , Cálcio da Dieta/metabolismo , Queijo/análise , Ácidos Graxos/sangue , Fezes/química , Hiperlipidemias/metabolismo , Eliminação Intestinal , Leite/metabolismo , Período Pós-Prandial , Animais , Cloreto de Cálcio/administração & dosagem , Cálcio da Dieta/administração & dosagem , Ácidos Graxos/administração & dosagem , Manipulação de Alimentos/métodos , Hiperlipidemias/sangue , Masculino , Valor Nutritivo , Ratos Wistar , Fatores de Tempo
19.
Food Res Int ; 92: 138-146, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28290291

RESUMO

The objective of this study was to compare the kinetics of the release of nutrients (peptides and fatty acids) from different dairy matrices (milks, yogurts, and cheeses) in a simulated gastrointestinal environment. Prior to processing, different heat and homogenization treatments were applied to milks, and different drainage pH levels were used to control calcium concentration in cheeses. The dairy matrices were then subjected to simulated digestion. Matrix degradation, protein hydrolysis, and fat hydrolysis were analyzed during the gastric and intestinal digestion phases. Intense heat treatment of milk induced faster digestion of proteins in the gastric environment. Cheeses were more resistant to protein and lipid digestion than liquid or semi-solid matrices were. No direct relationship could be established between disintegration kinetics and cheese rheological properties. Fatty acid release in the intestinal phase was much faster when matrices were produced from homogenized milk. For cheeses, greater fatty acid release could not be related to faster matrix disintegration, suggesting that the lipid droplet size dispersion was more important than matrix breakdown was for the modulation of lipid digestion kinetics. Calcium soaps were produced in the intestinal environment, and their concentration was higher during the digestion of cheeses in comparison with milks and yogurts. These results suggest that processing-induced modifications to the composition, microstructure, and rheological properties of dairy matrices could be used to control nutrient delivery.


Assuntos
Queijo/análise , Trato Gastrointestinal/metabolismo , Leite/química , Iogurte/análise , Animais , Cálcio da Dieta/análise , Digestão , Análise de Alimentos , Manipulação de Alimentos , Glicolipídeos/análise , Glicoproteínas/análise , Temperatura Alta , Concentração de Íons de Hidrogênio , Gotículas Lipídicas , Metabolismo dos Lipídeos , Proteínas do Leite/análise , Tamanho da Partícula , Reologia
20.
Am J Clin Nutr ; 106(6): 1358-1365, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28978543

RESUMO

Background: In a simulated gastrointestinal environment, the cheese matrix modulates dairy fat digestion. However, to our knowledge, the impact of the cheese matrix on postprandial lipemia in humans has not yet been evaluated.Objective: In healthy subjects, we compared the impact of dairy fat provided from firm cheese, soft cream cheese, and butter on the postprandial response at 4 h and on the incremental area under the curve (iAUC) of plasma triglycerides.Design: Forty-three healthy subjects were recruited to this randomized, crossover, controlled trial. In random order at intervals of 14 d and after a 12-h fast, subjects ingested 33 g fat from a firm cheese (young cheddar), a soft cream cheese (cream cheese), or butter (control) incorporated into standardized meals that were matched for macronutrient content. Plasma concentrations of triglycerides were measured immediately before the meal and 2, 4, 6, and 8 h after the meal.Results: Cheddar cheese, cream cheese, and butter induced similar increases in triglyceride concentrations at 4 h (change from baseline: +59%, +59%, and +62%, respectively; P = 0.9). No difference in the triglyceride iAUC0-8 h (P-meal = 0.9) was observed between the 3 meals. However, at 2 h, the triglyceride response caused by the cream cheese (change from baseline: +44%) was significantly greater than that induced by butter (change from baseline: +24%; P = 0.002) and cheddar cheese (change from baseline: +16%; P = 0.0004). At 6 h, the triglyceride response induced by cream cheese was significantly attenuated compared with that induced by cheddar cheese (change from baseline: +14% compared with +42%; P = 0.0004).Conclusion: This study demonstrates that the cheese matrix modulates the impact of dairy fat on postprandial lipemia in healthy subjects. This trial was registered at clinicaltrials.gov as NCT02623790.


Assuntos
Queijo , Gorduras na Dieta/sangue , Digestão , Refeições , Período Pós-Prandial , Triglicerídeos/sangue , Adulto , Área Sob a Curva , Estudos Cross-Over , Laticínios , Gorduras na Dieta/administração & dosagem , Ingestão de Alimentos , Ingestão de Energia , Feminino , Dureza , Humanos , Metabolismo dos Lipídeos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA