Publication: Süt serumu proteinlerinin peynir altı suyundan elde edilmesi
Abstract
Süt; su, yağ, proteinleri (esas olarak kazein miselleri ve süt serumu proteinleri), karbohidratları (esas olarak laktoz) ve az miktarda biyoaktif bileşenleri; mineraller, vitaminler ve enzimleri içeren kompleks biyolojik bir sıvıdır. Bileşiminde annede bulunan bağışıklık elemanları yer aldığından, aynı zamanda yenidoğanı enfeksiyonlara karşı pasif olarak korur. Sütte kazeinin çöktürülmesinden sonra supernatanda görülen proteinler peynir altı suyu (“whey”) proteinleri olarak adlandırılırlar. Peynir üretimi sırasında sütten ayrılan peynir altı suyu toz haline getirilerek gıda endüstrisinde yaygın olarak kullanılmaktadır. Peynir altı suyunun süt serumu proteinlerince zengin olduğu bilinmektedir. Majör süt serumu proteinleri β-laktoglobulin, a-laktalbümin, serum albümin, immünoglobülinler ve glikomakropeptittir. Peynir altı suyu ve onun bileşenleri; antioksidan aktivite, antikarsinojenik etki, immün düzenleme, pasif bağışıklık, hastalıktan koruma, antibakteriyel, antimikrobiyal ve antiviral etkiler, toksinleri bağlama, hücre büyümesini destekleme, platelet bağlama, antienflamatuar ve anti hipertansif etkiler dahil olmak üzere farklı biyolojik işlevlerde görev alırlar. Çalışmamızda bu işlevlere sahip olan ve endüstri yan ürünü olan peynir altı suyu tozundan süt serumu proteinlerini elde etmeyi amaçladık. Peynir altı suyu tozundaki (PAST) süt serumu proteinleri; membran filtrasyon ve kromatografi gibi yöntemler kullanılarak ayırma işlemleri gerçekleştirildi. Ön işlemlerden geçirilen peynir altı suyu tozu, 50,000 MWCO membran filtreye uygulandığında membrandaki tıkanmadan dolayı süt serumu proteinlerini ayrı ayrı elde etmek mümkün olmadı. Ön işlemlerden geçirilen peynir altı suyu tozu, Sephadex G-200 kromatografisine uygulandığında 3 fraksiyon elde edildi ve bu fraksiyonlardan birincinin Ig’ler ve BSA olduğu; ikinci fraksiyonun β-laktoglobulin ve a-laktalbümin olduğu; üçüncü fraksiyonun ise küçük peptidler olduğu SDS-PAGE yöntemiyle ispatlandı. Elde edilen F-2 fraksiyonu pepsin ile hidroliz edildiğinde β-laktoglobulin; tripsin ile hidroliz edildiğinde a-laktalbümince zengin fraksiyon elde edildi.
SEPARATION OF MILK SERUM PROTEINS IN WHEY Milk is a complex fluid that contains water, fat, proteins (mainly casein micelles and milk serum proteins), carbohydrates (mainly lactose) and trace amount of bioactive molecules including minerals, vitamins and enzymes. It contains molecules of the mother’s immune system and thus passively protects the newborn from infections. The proteins that appear in the supernatant after precipitation of casein in milk are called whey proteins. Whey is a product of cheese manufacture. This side product is powdered and commonly used in the nutritional industry. It is known that whey is rich in milk serum proteins. Major whey proteins are β-lactoglobulin, a-lactalbumin, serum albumin, immunoglobulins and glycomacropeptide. Whey and its components are involved in different biological functions including antioxidant activity, anticarcinogenic effects, immunomodulation, passive immunity, disease protection, anti-bacterial, anti-microbial and anti-viral effects, binding of toxins, promotion of cell growth, platelet binding, anti-inflammatory and anti-hypertensive actions. In this study, we aimed to obtain milk serum proteins in whey powder which is an industrial by product and have these functions. Milk serum proteins in whey were obtained by using membrane filtration and chromatographic methods. The pre-treated whey was applied to the 50,000 MWCO membrane filter. B ecause of the membrane fouling it was unable to have milk serum proteins separately. The pre-treated whey was applied to Sephadex G-200 chromatography and three fractions were obtained. SDS-PAGE method was used to identify the fractions; the first fraction was immunoglobulins and serum albumin; the second fraction was β-lactoglobulin and a-lactalbumin; the third fraction was small peptides. β-lactoglobulin is obtained after hydrolysis of F-2 fraction with pepsin and a-lactalbumin enriched product is obtained after hydrolysis of F-2 fraction with trypsin.
SEPARATION OF MILK SERUM PROTEINS IN WHEY Milk is a complex fluid that contains water, fat, proteins (mainly casein micelles and milk serum proteins), carbohydrates (mainly lactose) and trace amount of bioactive molecules including minerals, vitamins and enzymes. It contains molecules of the mother’s immune system and thus passively protects the newborn from infections. The proteins that appear in the supernatant after precipitation of casein in milk are called whey proteins. Whey is a product of cheese manufacture. This side product is powdered and commonly used in the nutritional industry. It is known that whey is rich in milk serum proteins. Major whey proteins are β-lactoglobulin, a-lactalbumin, serum albumin, immunoglobulins and glycomacropeptide. Whey and its components are involved in different biological functions including antioxidant activity, anticarcinogenic effects, immunomodulation, passive immunity, disease protection, anti-bacterial, anti-microbial and anti-viral effects, binding of toxins, promotion of cell growth, platelet binding, anti-inflammatory and anti-hypertensive actions. In this study, we aimed to obtain milk serum proteins in whey powder which is an industrial by product and have these functions. Milk serum proteins in whey were obtained by using membrane filtration and chromatographic methods. The pre-treated whey was applied to the 50,000 MWCO membrane filter. B ecause of the membrane fouling it was unable to have milk serum proteins separately. The pre-treated whey was applied to Sephadex G-200 chromatography and three fractions were obtained. SDS-PAGE method was used to identify the fractions; the first fraction was immunoglobulins and serum albumin; the second fraction was β-lactoglobulin and a-lactalbumin; the third fraction was small peptides. β-lactoglobulin is obtained after hydrolysis of F-2 fraction with pepsin and a-lactalbumin enriched product is obtained after hydrolysis of F-2 fraction with trypsin.