The association of chymosin with artificial casein micelles

Roos, A.L. de; Geurts, T.J.; Walstra, P.

doi:10.1016/s0958-6946(00)00050-9

Cited by 14 publications

(11 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The negative effect was indirectly confirmed by St-Gelais and Haché (2005), who found poor coagulation in milk samples enriched with β-CN and, in agreement with Dunnewind et al (1996) andDe Roos et al (2000), reported a reduction in the affinity between κ-CN and chymosin after the addition of β-CN. According to these studies, this fraction seems to act as a competitor with the proteolytic enzyme or as a shield for the enzyme binding sites during coagulation.…”

Section: Effects Of β-Cn On Milk Coagulation Curd Firming and Synersupporting

confidence: 73%

Milk protein fractions strongly affect the patterns of coagulation, curd firming, and syneresis

Amalfitano

Cipolat‐Gotet

Cecchinato

et al. 2019

Journal of Dairy Science

View full text Add to dashboard Cite

The aim of this study was to assess the role of milk protein fractions in the coagulation, curd firming, and syneresis of bovine milk. Analyses were performed on 1,271 individual milk samples from Brown Swiss cows reared in 85 herds classified into 4 types of farming systems, from the very traditional (tied cows, feed manually distributed, summer highland pasture) to the most modern (loose cows, use of total mixed rations with or without silage). Fractions α S1 -casein (CN), α S2 -CN, β-CN, κ-CN, β-lactoglobulin (LG), and α-lactalbumin (LA) and genotypes at CSN2, CSN3, and BLG were obtained by reversed-phase HPLC. The following milk coagulation properties were measured with a lactodynamograph, with the testing time extended to 60 min: rennet coagulation time (RCT, min), curd firming time (min), and curd firmness at 30 and 45 min (mm). All the curd firmness measures recorded over time (total of 240 observations/sample) were used in a 4-parameter nonlinear model to obtain parameters of coagulation, curd firming, and syneresis: RCT estimated from the equation (min), asymptotic potential curd firmness (mm), the curd firming and syneresis instant rate constants (%/min), and the maximum curd firmness value (CF max , mm) and the time taken to reach it (min). All the aforementioned traits were analyzed with 2 linear mixed models, which tested the effects of the protein fractions expressed in different ways: in the first, quantitative model, each protein fraction was expressed as content in milk; in the second, qualitative model, each protein fraction was expressed as a percentage of total casein content. Besides proteins, additional nuisance parameters were herd (included as a random effect), daily milk production (only for the quantitative model), casein content (only for the qualitative model), dairy system, parity, days in milk, the pendulum of the lactodynamograph, and the CSN2, CSN3, and BLG genotypes. Both α S1 -CN and β-CN showed a clear and favorable effect on CF max , where the former effect was almost double the latter. Milk coagulation ability was favorably affected by κ-CN, which reduced both the RCT and RCT estimated from the equation, increased the curd firming and syneresis instant rate constants, and allowed a higher CF max to be reached. In contrast, α S2 -CN delayed gelation time and β-LG worsened curd firming, both resulting in a low CF max . The results of this study suggest that modification of the relative contents of specific protein fractions can have an enormous effect on the technological behavior of bovine milk.

show abstract

Section: Effects Of β-Cn On Milk Coagulation Curd Firming and Synersupporting

confidence: 73%

Milk protein fractions strongly affect the patterns of coagulation, curd firming, and syneresis

Amalfitano

Cipolat‐Gotet

Cecchinato

et al. 2019

Journal of Dairy Science

View full text Add to dashboard Cite

show abstract

“…More studies have been carried out on β-CN and its relationship with coagulation and curd firming processes, including its use in technological treatments to enrich the natural composition of milk (St-Gelais and Haché, 2005), than on α-proteins. Several authors (Dunnewind et al, 1996;De Roos et al, 2000) have found a large reduction in the association between κ-CN and chymosin following addition of a small amount of β-CN to the milk solution. It seems that the role of chymosin in one or more binding sites located on para-κ-CN is shielded by β-CN, or it may even be that this protein fraction is a competitor of chymosin during enzymatic coagulation of these binding sites.…”

Section: Effect Of β-Cnmentioning

confidence: 99%

Variations in milk protein fractions affect the efficiency of the cheese-making process

Cipolat‐Gotet

Cecchinato

Malacarne

et al. 2018

Journal of Dairy Science

View full text Add to dashboard Cite

The aim of this study was to assess the influence of the amounts of the α-, α-, β-, and κ-casein (CN) and the α-lactalbumin and β-lactoglobulin protein fractions on the efficiency of the cheese-making process independently of their genetic polymorphisms. The study was carried out on milk samples from 1,271 Brown Swiss cows from 85 herds classified into 4 categories according to management, feeding, and housing characteristics (traditional and modern systems). To assess the efficiency of the cheese-making process, we processed the milk samples according to a laboratory cheese-making procedure (1,500 mL/sample) and obtained the following measures: (1) 3 percentage cheese yields (%CY, %CY, %CY), (2) 2 daily cheese yields obtained by multiplying %CY (curd and total solids) by daily milk yields (dCY, dCY), (3) 4 measures of nutrient recovery in the curd (REC, REC, REC, REC), and (4) 2 measures of cheese-making efficiency in terms of the ratio between the observed and theoretical %CY (Ef-%CY, Ef-%CY). All the aforementioned traits were analyzed by fitting 2 linear mixed models with protein fractions as fixed effects expressed as percentage in the milk (model M-%milk) and as percentage of the total casein content (model M-%cas) together with the effects of total casein content (only in model M-%cas), daily milk yield (only in model M-%milk; not for dCY traits), dairy system, herd (random effect), days in milk, parity, and vat. The efficiency of overall cheese yield (Ef-%CY) was mostly positively associated with β-CN content in the milk, whereas Ef-%CY was greater with higher amounts of κ-CN and α-CN (M-%milk) due to the strong influence of both fractions on the recovery rate of milk components in the curd (fat and total solids, protein with α-CN only) when expressed as percentage of milk and of total casein; only β-CN was more important for REC. In contrast, we found β-lactoglobulin to be highly negatively related to all the traits related to the cheese-making process and to the daily cheese yield per cow, whereas α-lactalbumin was positively associated with the latter traits. Additional research on this topic is needed, with particular focus on the genetic and genomic aspects of the role of protein fractions in the cheese-making process and on the associations between genetic polymorphisms in milk protein and milk nutrient recovery in the curd.

show abstract

“…Banks et al [11] and Banks [10] thus lowered the renneting pH of milk heated at 90°C for 30 s or 1 min from pH ~ 6.5 to 5.8 or 6.2 to make Cheddar cheese. However, acidification also increases association of the enzyme with the casein molecules [36], and therefore retention of the enzyme in the curd, where its strong activity leads to increased proteolysis [27,51,69,159]. This effect is more significant in rennet-type curds such as Cheddar [69], where acidification in conventional processes essentially follows a fast renneting step and is usually limited, than in soft cheeses where acidification starts prior to rennet addition and largely proceeds throughout the renneting process, curd development and drainage [51].…”

Section: Technological Means Used To Restore the Cheese-making Propermentioning

confidence: 99%

Formation of heat-induced protein aggregates in milk as a means to recover the whey protein fraction in cheese manufacture, and potential of heat-treating milk at alkaline pH values in order to keep its rennet coagulation properties. A review

Guyomarc’H

2006

Lait

View full text Add to dashboard Cite

-The heat-treatment of cheese milk, or whey, to denature the whey proteins has long been the most applied means of recovering these proteins, either directly in the cheese curd, or as added to the cheese milk prior to renneting. In heat-treated milk, the interaction of the denatured whey proteins with the casein micelles, however, limits the primary phase of the enzymatic reaction, and prevents fusion of the casein micelles. Cheeses containing heat-denatured whey proteins also exhibit excessive moisture, a crumbly and soft texture, and poor meltability. Various technological means to reduce these drawbacks are reviewed. Especially, it is generally accepted that the heat-treatment of skim milk at alkaline pH generates aggregates of denatured whey proteins and κ-casein in the serum phase of milk, rather than on the surface of the casein micelles. As a consequence, the casein micelles are depleted in κ-casein, and free of denatured whey proteins. However, the attempts made to exploit this interesting protein distribution in cheese-making remain scarce, despite their promising results. Résumé -Récupération des protéines sériques du lait dans le caillé fromager au moyen de la formation d'agrégats thermo-induits, et intérêt de chauffer le lait à pH alcalin dans le but de conserver son aptitude à la coagulation présure. Revue. Le traitement thermique du lait ou de lactosérum est un des moyens les plus utilisés pour incorporer les protéines sériques ainsi dénatu-rées, soit directement dans le caillé, soit sous forme d'ingrédient ajouté au lait fromager. Cependant, l'interaction entre les protéines sériques dénaturées et les micelles de caséines, due au chauffage du lait, a pour effet de limiter la phase primaire de la coagulation par la présure, ainsi que la fusion des micelles déstabilisées. Les fromages obtenus à partir de lait chauffé sont aussi plus humides, plus mous, plus granuleux et moins aptes à la fonte que les fromages standards. Les moyens technologiques de pallier ces inconvénients sont rappelés. En particulier, il est connu que le traitement thermique du lait à pH alcalin favorise la formation d'agrégats de protéines sériques dénaturées et de caséine κ dans la phase soluble du lait, plutôt qu'en surface des micelles de caséines. En consé-quence, la teneur en caséine κ des micelles est réduite et celles-ci ne sont pas recouvertes de protéi-nes sériques dénaturées. Cependant, peu d'études ont tenté d'exploiter ces caractéristiques du lait chauffé à pH alcalin en technologie fromagère, malgré des résultats prometteurs. coagulation présure / traitement thermique / protéine sérique / fromage

show abstract

The association of chymosin with artificial casein micelles

Cited by 14 publications

References 10 publications

Milk protein fractions strongly affect the patterns of coagulation, curd firming, and syneresis

Milk protein fractions strongly affect the patterns of coagulation, curd firming, and syneresis

Variations in milk protein fractions affect the efficiency of the cheese-making process

Formation of heat-induced protein aggregates in milk as a means to recover the whey protein fraction in cheese manufacture, and potential of heat-treating milk at alkaline pH values in order to keep its rennet coagulation properties. A review

Contact Info

Product

Resources

About