Composition of casein micelles in relation to size in goat milks with A and null αs1-casein variants

Aimar, Pierre; Michel, Françoise; Zahoute, Laurence

doi:10.1016/s0958-6946(99)00057-6

Cited by 14 publications

(7 citation statements)

References 9 publications

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“…These differences were statistically significant and in good agreement with previous studies (Pierre et al 1995(Pierre et al , 1998a(Pierre et al , 1999Tziboula and Horne 1999), all of which concluded that the mean size of casein micelles increased as the level of α s1 -casein decreased. Caseinmicelles in caprine milks with a low content of α s1 -casein have been described as more highly hydrated than those from milks having a high content of this protein (Mora-Gutierrez et al 1997).…”

Section: Resultssupporting

confidence: 92%

Extreme frequencies of the α_s1-casein “null” variant in milk from Norwegian dairy goats – Implications for milk composition, micellar size and renneting properties

Devold

Nordbø

Langsrud

et al. 2010

Dairy Sci. Technol.

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Caprine α s1 -casein polymorphism is one of the key factors which determines important technological properties of milk, such as rennetability and cheese yield. The indigenous Norwegian goat breed is characterized by a remarkably high frequency (>70%) of a "null" variant of α s1 -casein unique to this population. This mutation, referred to as the exon 12 D allele, involves a single base deletion in exon 12 of the α s1 -casein gene. The aim of this study was to provide more detailed information on how α s1 -casein polymorphism affects composition and rennet coagulation properties of milk from Norwegian dairy goats. Class of α s1 -casein significantly affected milk composition; crude protein, casein and pH. The mean casein micelle size was larger in milks containing α s1 -casein "null" variant when compared to "strong" milks; in contrast, the heat-induced changes in micelle size appeared to be least pronounced in this group. Compositional differences between "strong" and "null" milks may explain these differences. α s1 -Casein class had a significant effect on gel strength recorded 30 min after the addition of rennet, with the "strong" milks giving the greatest firmness. However, a considerable fraction of the milk samples in this study were unable to form a strong clot, regardless of the α s1 -casein variant. These results indicate that environmental and compositional factors not considered in this study may be important in the curd formation process.

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Section: Resultssupporting

confidence: 92%

Extreme frequencies of the α_s1-casein “null” variant in milk from Norwegian dairy goats – Implications for milk composition, micellar size and renneting properties

Devold

Nordbø

Langsrud

et al. 2010

Dairy Sci. Technol.

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“…The other notable trend was that the micellar size was negatively correlated with all milk components. The association observed between the milk components is in agreement with results from different scholars (Pierre et al, 1999;Clark and Sherbon, 2000) CONCLUSIONS A total of 35 new mutations, 3 in the 5 UTR, 3 in the exon, and 29 in the intron regions of the CSN1S1 gene, were detected. One of the new mutations that involved the shift of amino acid Gln 77 → Pro 77 is a drastic shift and is of particular interest due to the effect it may have in the protein molecule, including structural effect, physical property effect, and digestion and formation of a different peptide pattern.…”

Section: Principal Component Analysis and Association Between New Mutation And Selected Milk Componentssupporting

confidence: 89%

“…Overall, the range for the 3 genotypes agreed with what has been reported for the stronger genetic variants of α s1 -CN, although there are some contradicting reports. In a study by Pierre et al (1999), a narrow range was reported to be associated with the strong variant (A-milk), whereas Tziboula and Horne (1999) reported the contrary. What can be generalized from the various reports is that the lower mean sizes and narrower ranges are always associated with the strong genetic variants of α s1 -CN.…”

Section: Mean Casein Micellar Size As Influenced By the New Mutationmentioning

confidence: 96%

“…With this in view, many European goat breeds have been extensively investigated. The high expression level genotypes are known to predominate among the French (Pierre et al, 1999), Spanish (Jordana et al, 1996), and Italian (Sacchi et al, 2005) goat breeds, where efficient selection to increase their frequency has been performed, whereas a null variant predominates in breeds such as the Norwegian dairy goats (Hayes et al, 2006;Devold et al, 2010;Dagnachew et al, 2011). Little information exists on African breeds concerning expression of the CSN1S1 gene (Tadlaoui Ouafi et al, 2002;Caroli et al, 2007;Vacca et al, 2009), and no information exists on indigenous Ethiopian goat breeds.…”

Section: Introductionmentioning

confidence: 99%

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Newly identified mutations at the CSN1S1 gene in Ethiopian goats affect casein content and coagulation properties of their milk

Mestawet

Girma

Ådnøy

et al. 2013

Journal of Dairy Science

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Very high casein content and good coagulation properties previously observed in some Ethiopian goat breeds led to investigating the αs1-casein (CSN1S1) gene in these breeds. Selected regions of the CSN1S1 gene were sequenced in 115 goats from 5 breeds (2 indigenous: Arsi-Bale and Somali, 1 exotic: Boer, and 2 crossbreeds: Boer × Arsi-Bale and Boer × Somali). The DNA analysis resulted in 35 new mutations: 3 in exons, 3 in the 5' untranslated region (UTR), and 29 in the introns. The mutations in exons that resulted in an amino acid shift were then picked to evaluate their influence on individual casein content (αs1-, αs2-, β-, and κ-CN), micellar size, and coagulation properties in the milk from the 5 goat breeds. A mutation at nucleotide 10657 (exon 10) involved a transversion: CAG→CCG, resulting in an amino acid exchange Gln77→Pro77. This mutation was associated with the indigenous breeds only. Two new mutations, at nucleotide 6072 (exon 4) and 12165 (exon 12), revealed synonymous transitions: GTC→GTT in Val15 and AGA→AGG in Arg100 of the mature protein. Transitions G→A and C→T at nucleotides 1374 and 1866, respectively, occurred in the 5' UTR, whereas the third mutation involved a transversion T→G at nucleotide location 1592. The goats were grouped into homozygote new (CC), homozygote reference (AA), and heterozygote (CA) based on the nucleotide that involved the transversion. The content of αs1-CN (15.32g/kg) in milk samples of goats homozygous (CC) for this newly identified mutation, Gln77→Pro77 was significantly higher than in milks of heterozygous (CA; 9.05g/kg) and reference (AA; 7.61g/kg) genotype animals. The αs2-, β-, and κ-CN contents showed a similar pattern. Milk from goats with a homozygous new mutation had significantly lower micellar size. Milk from both homozygote and heterozygote new-mutation goats had significantly shorter coagulation rate and stronger gel than the reference genotype. Except the transversion, the sequence corresponded to allele A and presumably derived from it. Therefore, this allele is denoted by A3. All goats from the reference genotype (AA) were homozygous for the allele at nucleotide position 1374 and 1866, whereas all mutations in the 5' UTR existed in a heterozygous form in both heterozygous (CA) and the new mutation (CC) genotype. The newly identified mutation (CC) detected in some of the goat breeds is, therefore, important in selection for genetic improvement and high-quality milk for the emerging goat cheese-producing industries. The finding will also benefit farmers raising these goat breeds due to the increased selling price of goats. Further studies should investigate the effect of this amino acid exchange on the secondary and tertiary structure of the αs1-CN molecule and on the susceptibility of peptide hydrolysis by digestive enzymes.

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“…Barbaro e Calapaj (1958) apud Le Jaouen (1981) encontraram maior freqüência de micelas de caseína com diâmetros de 50 e 75 nm em leites de cabra e vaca, respectivamente. O tamanho das micelas depende do tipo de caseína observada, por exemplo, em micelas maiores são encontrados maiores teores de α s2 -caseína, por outro lado, em micelas menores há maiores teores de κ-caseína (PIERRE et al, 1999). Vegarud et al (1999) na Noruega, observaram grande variação no tamanho das micelas presentes no leite de cabras de diferentes rebanhos e entre indivíduos do mesmo rebanho.…”

Section: Características Do Leiteunclassified

Uso nutricional e terapêutico do leite de cabra

Ribeiro

2004

Sem. Ci. Agr.

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Resumo: Esta revisão de literatura teve como objetivo descrever a composição e a utilização do leite de cabra na alimentação humana. Por seu alto valor nutricional, boa digestibilidade, boa aceitação e um baixo potencial alergênico, o leite de cabra tem sido recomendado para crianças, pessoas idosas e convalescentes. Porém, o leite de cabra não pode ser recomendado indistintamente para todas as crianças alérgicas ao leite de vaca, pois a sua utilização pode causar, em alguns casos, sérios danos à saúde das mesmas. Palavras-chave: alergia, composição do leite, lactente, valor nutricional.Abstract: This literature review had as objectives to describe the goats milk composition and its utilization in human feed. Due its good nutritional value, good digestibility and acceptability, and a low allergenic potential, the goat's milk has been recommended for children, elderly and convalescent persons. However, it cannot be recommended to every child allergic to cow's milk, because in some cases, serious threat to life can also occur with goat's milk. Key words: allergy, milk composition, infant, nutritional value. IntroduçãoA caprinocultura representa uma atividade pecuária importante para a maioria dos países, porém está mais concentrada nas regiões tropicais e ou semi-áridas. A finalidade da atividade tem sido o fornecimento de alimentos e matéria prima de vestuário à população humana. O nível de eficiência da produção de caprinos varia de país para país, em decorrência, principalmente, do nível de desenvolvimento do país (FIGUEIREDO, 1990). Os principais produtos oriundos da atividade são a carne, o leite, a pele, a fibra e o estrume; a importância de cada um destes produtos pode variar de acordo com o local onde a atividade está sendo desenvolvida, a raça criada, entre outros fatores.A exploração dos caprinos para a produção de leite é bastante antiga, já aparecendo na mitologia grega, onde Zeus teria sido alimentado com leite da cabra Amaltéia (GRIMAL, 1983). A exploração dos caprinos para leite tem crescido, porque além do leite ser considerado um produto de alto valor nutritivo, os caprinos têm a capacidade de se adaptar a condições criatórias variáveis, podendo proporcionar a famílias de baixa renda familiar, e a população em geral, uma melhoria do nível nutricional da dieta (FIGUEIREDO, 1990;MEDEIROS et al., 1994;KNIGHTS;GARCIA, 1997). Segundo Ribeiro (1997) o uso de leite de cabras por indicação médica tem sido um dos carros chefes a promover a caprinocultura leiteira. De acordo com Pellerin (2001), o leite de cabra apresenta propriedades bioquímicas que favorecem seu valor nutricional, sendo recomendado para crianças, particularmente para aquelas intolerantes ao leite de vaca, para pessoas com doenças gastrointestinais, ou mesmo como suplemento para pessoas idosas e malnutridas. As populações dos países em desenvolvimento, onde a caprinocultura é mais importante numericamente, podem ser sensivelmente beneficiadas com a produção de leite caprino (KNIGHTS; GARCIA, 1997;PELLERIN, 2001).O leite materno, por suas v...

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Composition of casein micelles in relation to size in goat milks with A and null αs1-casein variants

Cited by 14 publications

References 9 publications

Extreme frequencies of the α_s1-casein “null” variant in milk from Norwegian dairy goats – Implications for milk composition, micellar size and renneting properties

Extreme frequencies of the α_s1-casein “null” variant in milk from Norwegian dairy goats – Implications for milk composition, micellar size and renneting properties

Newly identified mutations at the CSN1S1 gene in Ethiopian goats affect casein content and coagulation properties of their milk

Uso nutricional e terapêutico do leite de cabra

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Composition of casein micelles in relation to size in goat milks with A and null αs1-casein variants

Cited by 14 publications

References 9 publications

Extreme frequencies of the αs1-casein “null” variant in milk from Norwegian dairy goats – Implications for milk composition, micellar size and renneting properties

Extreme frequencies of the αs1-casein “null” variant in milk from Norwegian dairy goats – Implications for milk composition, micellar size and renneting properties

Newly identified mutations at the CSN1S1 gene in Ethiopian goats affect casein content and coagulation properties of their milk

Uso nutricional e terapêutico do leite de cabra

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Extreme frequencies of the α_s1-casein “null” variant in milk from Norwegian dairy goats – Implications for milk composition, micellar size and renneting properties

Extreme frequencies of the α_s1-casein “null” variant in milk from Norwegian dairy goats – Implications for milk composition, micellar size and renneting properties