Characterization of intermediates formed during heat-induced aggregation of -lactoglobulin AB at neutral pH

Schokker, E.P.; Singh, Harjinder; Pinder, D. N.; Norris, Gillian E.; Creamer, Lawrence K.

doi:10.1016/s0958-6946(99)00148-x

Cited by 116 publications

(111 citation statements)

References 34 publications

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“…mol -1 ) and of aggregated forms in addition to the dimeric form (D3 5 300 g . mol -1 ), which is in accordance with previous studies on heat-induced aggregation of BLG [38]. explaining the presence of monomeric forms of glycated protein in contrast with what was observed in the case of native and heated BLG.…”

Section: Determination Of the Modification Degreesupporting

confidence: 92%

Maillard glycation of $\beta$-lactoglobulin with several sugars: comparative study of the properties of the obtained polymers and of the substituted sites

Chevalier¹,

Chobert²,

Mollé

et al. 2001

Lait

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-Maillard reactions represent a major cause of structural and chemical modifications of proteins during industrial food processing and storage. Nutritional and functional properties of food proteins are highly dependent on this reaction. A better knowledge of this modification and of its structural consequences presents a great interest for the food industry. In this study, β-lactoglobulin was heated in solution at 60 o C in the presence of arabinose, galactose, glucose, lactose, rhamnose and ribose. Protein polymerization and glycation site specificity were investigated according to the nature of sugar used for modification of β-lactoglobulin. Among the six common sugars used, arabinose and ribose induced the highest degree of modification. Glucose, galactose and rhamnose were less reactive and lactose generated the lowest degree of modification. Proteins substituted with ribose or arabinose formed polymers stabilized by sugar induced covalent bonds. When other sugars were used, part of the aggregated proteins were stabilized only by hydrophobic interaction and disulfide bonds. The site specificity for the attachment of each sugar could not be clearly demonstrated. According to mass spectrometry analysis, leucine 1 (N-teminal amino acid), lysine 14 and lysine 47 were modified in the presence of galactose, glucose or lactose. Lysines 69, 75 and 135 were modified only in the case of protein glycated with glucose. Lysine 100 was modified only when protein was glycated with lactose. No glycation site could be detected for proteins glycated with ribose or arabinose due to the higher degree of modification and polymerization which inhibited the tryptic hydrolysis used before mass spectrometry analysis. Résumé -Glycation de la -lactoglobuline par réaction de Maillard à l'aide de différents sucres : étude comparative des propriétés des polymères obtenus et des sites de substitution. Les réactions de Maillard sont une cause majeure de modifications structurale et chimique des protéines au cours des traitements thermiques alimentaires et du stockage. Les propriétés nutritionnelles et fonctionnelles des protéines alimentaires dépendant beaucoup de cette réaction, une meilleure connaissance de cette modification et de ses conséquences structurales présente un grand intérêt pour les industriels. Dans cette étude, la β-lactoglobuline a été chauffée en solution à 60 o C en présence d'arabinose, de galactose, de glucose, de lactose, de rhamnose et de ribose. Le type de polymérisation obtenu ainsi que les sites de glycation ont été déterminés en fonction de la nature du sucre utilisé. L'arabinose et le ribose conduisaient au plus haut degré de modification. Le glucose, le galactose et le rhamnose étaient moins réactifs alors que le lactose était à l'origine du taux de modification le plus bas. Les protéines substituées par le ribose ou l'arabinose formaient des polymères stabilisés par des liaisons covalentes induites par les sucres. En utilisant d'autres sucres, une partie des protéines agré-gées était stabilisée uniq...

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Section: Determination Of the Modification Degreesupporting

confidence: 92%

Maillard glycation of $\beta$-lactoglobulin with several sugars: comparative study of the properties of the obtained polymers and of the substituted sites

Chevalier¹,

Chobert²,

Mollé

et al. 2001

Lait

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“…The results of Native-PAGE were quantified with gel densitometry, in attempts to measure the loss of the major native whey proteins. Since the amount of bound dye is proportional to the protein content, changes in the amount of protein fractions can be detected through the integrated intensities of whey protein bands (Anema & Li, 2003;Pa 'sztor-Husza 'r, 2008;Schokker, Singh, Pinder, Norris, & Creamer, 1999). Table 2 displays the contents, in percentage of native whey proteins, determined by Native-PAGE during heating treatments.…”

Section: Whey Protein Denaturationmentioning

confidence: 99%

“…Samples heated for 5 min at 85 o C and analyzed by RP-HPLC showed a rather low percentage of native lg (~8%), whereas a considerable amount of protein with the same electrophoretic mobility as native lg (~25e35%) was still observed through Native-PAGE after the same heat treatment. This could simply be due to a greater sensitivity of PAGE technique, or else indicate that some of the irreversibly altered whey proteins had the same electrophoretic mobility as their native counterparts (Schokker et al, 1999).…”

Section: Whey Protein Denaturationmentioning

confidence: 99%

Influence of moderate electric fields on gelation of whey protein isolate

et al. 2015

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Proteins are one of the food constituents most affected by heating, and some of the changes involve their unfolding, denaturation and gelation. Ohmic heating has often been claimed to improve the quality of foodstuffs due to its uniform heating and (putative) presence of a moderate electric field (MEF). However, this is still subject to discussion, so it is important to determine the effect of ohmic heating and of its MEF upon food constituents. Hence, the aim of this work was to evaluate the effects of MEF on denaturation, aggregation and viscoelastic properties of whey protein isolate (WPI), and compare them with those obtained via conventional heating under identical treatment conditions (up to 30 min at 85 o C). Results have shown that MEF interferes with whey protein unfolding and aggregation pathways at relatively high temperatures. MEF treatments have resulted in WPI solutions possessing more 8 and 10% of native Lactoglobulin and Lactalbumin, respectively, after 30 s of heating at 85 o C, when compared with a conventional heating method. Protein aggregates from MEF-treated WPI solutions presented a maximum increase in size of 78 nm, whereas conventional heating produced an increase of 86 nm. Unlike in conventional heating, aggregation of whey proteins during MEF was not sufficiently strong to form a true elastic gel network, since decreases in both storage and loss modulus were observed following MEF treatment. Our results suggest that MEF may provide a novel method for production of a whey protein matrix with distinctive gel-forming properties.2

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“…The principal component of whey protein is β-LG, a globular protein with a molar mass of 18.3 kDa, containing two disulfide bonds and one free thiol group (Swaisgood, 1982). With heating, this protein dominates the aggregation and gelation behaviour of whey proteins (Schokker et al, 1999). The second most abundant protein, α-LA, is also globular, with a molar mass of 14.2 kDa (Swaisgood, 1982).…”

Section: Introductionmentioning

confidence: 99%

“…Aggregation and gelation of whey proteins occurs with heating at 70 o C and above. At these temperatures, whey proteins unfold and irreversibly aggregate through exposed hydrophobic groups (Schokker et al, 1999). Whey protein gelation is affected by the addition of polysaccharide (Beaulieu et al, 2005;Capron et al, 1999;Ould Eleya and Turgeon, 2000).…”

Section: Introductionmentioning

confidence: 99%

Effect of Whey Protein Isolate on Ice Recrystallization Characteristics in Whey Protein Isolate/κ-Carrageenan Matrix

Chun¹,

Kim²,

Min³

2012

Korean Journal for Food Science of Animal Resources

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This study was carried out to investigate the physical and thermal properties of κ-carrageenan (κ-car) gel added whey protein isolate (WPI) as a cryoprotectant. The concentration of κ-carrageenan was fixed at 0.2 wt%. The mean ice crystal size of the WPI/κ-car was decreased according to increasing whey protein isolate concentration. The temperature of gel-sol (Tg-s) and sol-gel (Ts-g) transition of WPI/κ-car maxtrix was represented in the order of 3.0, 0.2, 5.0 and 1.0 wt%. In addition, the transition temperature of gel-sol of WPI in sucrose solution were showed in order of 1.0, 5.0, 0.2 and 3.0 wt% depending on whey protein isolate concentration. The shape of ice crystal was divided largely into two types, round and rectangular form. 1.0 wt% WPI/κ-car matrix at pH 7 and 9 showed minute and rectangular formation of ice crystals and whey protein isolate in sucrose solution at a concentration of 1.0 wt% WPI/κ-car matrix at pH 3 and 5 showed relatively large size and round ice crystals. The ice recrystallization characteristics and cryprotective effect of κ-carrageenan changed through the addition of different concentrations of whey protein isolate. It seems that the conformational changes induced interactions between whey protein isolate and κ-carrageenan affected ice recrystallization.

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Characterization of intermediates formed during heat-induced aggregation of -lactoglobulin AB at neutral pH

Cited by 116 publications

References 34 publications

Maillard glycation of $\beta$-lactoglobulin with several sugars: comparative study of the properties of the obtained polymers and of the substituted sites

Maillard glycation of $\beta$-lactoglobulin with several sugars: comparative study of the properties of the obtained polymers and of the substituted sites

Influence of moderate electric fields on gelation of whey protein isolate

Effect of Whey Protein Isolate on Ice Recrystallization Characteristics in Whey Protein Isolate/κ-Carrageenan Matrix

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