Keçi sütlerinde ısıl işlem uygulamasının süt melatonin ve vitamin c düzeylerine etkilerinin araştırılması
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Dosyalar
Tarih
2020
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Hatay Mustafa Kemal Üniversitesi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Amaç: Bu projede keçi sütünde pastörizasyon işlemi (72 oC'de 15 saniye) ve geleneksel olarak evlerde uygulanan kaynatma işleminin (100 oC'de 5 dakika) süt melatonin, vitamin C ve total protein düzeylerine etkilerinin araştırılması amaçlandı. Materyal ve Metot: Çalışmada özel bir keçi çiftliğinden, nisan ayında temin edilen 20 adet sağlıklı keçinin (10 Halep, 10 Kilis keçisi) sütü materyal olarak kullanıldı. Sütler, sabah meradan dönen (10:30-11:00 arasında) keçilerden rutin süt sağımı sırasında temin edildi. Her bir süt örneği, çiğ süt, pastörizasyon işlemi (72 oC'de 15 saniye) ve kaynatma işlemi (100 oC'de 5 dakika) uygulanan olmak üzere 3'e bölündü. Çiğ, pastörize ve kaynatılmış sütlerde melatonin düzeyleri ticari ELİSA kiti ile, vitamin C ve total protein düzeyleri manuel spekrotofotometrik yöntemlerle belirlendi. Bulgular: Kaynatma işlemi uygulanan süt örneklerinde melatonin düzeyleri (4,20±0,39 pg/ml), çiğ süt (3,19 ± 0,25 pg/ml) ve pastörizayon işlemi (3,42 ± 0,24 pg/ml) uygulanan örneklere kıyasla yükseldi (p <0,05). Vitamin C düzeyleri pastörizasyon uygulanan grupta (2,99±0,16 mg/100 ml), çiğ süt grubuna (3,18±0,24 mg/100 ml) göre önemli bir farklılık göstermedi (p >0,05). Kaynatma sonrasında elde edilen vitamin C düzeyleri ise (2,03 ± 0,12 mg/100 ml), hem çiğ süt hem de pastörize süt vitamin C düzeylerinden düşük (p <0,001) olarak saptandı. Total protein düzeyleri değerlendirildiğinde, Bradford yöntemi ile belirlenen total protein düzeyleri açısından ısıl işlem uygulanan gruplar arasında bir farklılık yok iken Lowry yöntemi ile belirlenen total protein düzeyleri, kaynatma uygulanan grupta, diğer gruplara göre önemli düzeyde düştü (p <0,001). Çiğ süt ve pastörize sütteki total protein düzeyleri Bradford yöntemi ve Lowry yöntemi ile belirlenen düzeyler açısından birbiri ile yakın bulundu. Diğer yandan kaynatma uygulanan sütlerde Bradford yöntemi ile belirlenen total protein düzeyleri (2,26 ± 0,13 g/dl), Lowry medodu ile belirlenen total protein düzeylerinden (1,92 ± 0,09 g/dl) yüksek olarak belirlendi (p<0,05). Pastörizasyon (r=-0,114, p<0,05) ve kaynatma (r=-0,572, p <0,01) uygulanan sütlerde melatonin ve vitamin C düzeyleri arasında önemli ancak zayıf negatif korelasyonlar belirlendi. Çiğ süt (r=0,723, p <0,01), pastörizasyon (r=0,838, p <0,01) ve kaynatma (r=0,449, p <0,05) uygulanan süt örneklerinde Bradford ve Lowry yöntemleri ile belirlenen total protein düzeyleri arasında pozitif korelasyonlar belirlendi. Sonuç: Keçi sütüne uygulanan pastörizasyon işleminin, süt melatonin, vitamin C ve total protein düzeylerini değiştirmediği, kaynatma uygulamasının ise vitamin C ve total protein düzeylerinin düşmesine neden olduğu belirlendi. Keçi sütünün biyoyararlanımında pastörizasyon işleminin, geleneksel kaynatma işlemine göre daha üstün olduğu düşünüldü. Sütlerde ELİSA metodu ile melatonin analizi yapılmadan önce, melatoninin sütte bağlı bulunduğu proteinden ayrıştırılması amacıyla, sütün, bir ön işlemden geçirilmesinin, sonuçların daha doğru olarak tespit edilmesinde faydalı olabileceği öngörüldü.
Aim: In this project, it was aimed to investigate the effects of pasteurization (15 seconds at 72 ºC) and boiling processes (5 minutes at 100 ºC) on goat milk melatonin, vitamin C and total protein levels. Material and Methods: The milk of 20 healthy goats (10 Aleppo, 10 Kilis goats) obtained from a private goat farm were used as materials. In April, milk was supplied from goats that returned from pasture in the morning (between 10:30 and 11:00) during routine milking. Each milk sample was divided into 3 for raw milk, for pasteurization process (15 seconds at 72 ºC) and for boiling process (5 minutes at 100 ºC). Melatonin levels in raw, pasteurized and boiled milk were determined with commercial ELISA kit, while, vitamin C and total protein levels were determined by manual spectrophotometric methods. Results: Melatonin levels in boiled milk samples (4.20 ± 0.39 pg/ml) increased (p <0.05) compared to both raw milk (3.19 ± 0.25 pg/ml) and pasteurized (3.42 ± 0.24 pg/ml) milk samples. Vitamin C levels did not differ in the pasteurization group (2.99 ± 0.16 mg/100 ml) compared to the raw milk group (3.18 ± 0.24 mg/100 ml). On the other hand, vitamin C levels obtained after boiling process (2.03 ± 0.12 mg/100 ml) were lower than that in the raw and pasteurized milk samples (p <0.001). While there was no difference between the heat treated groups in terms of total protein levels determined by Bradford method, the total protein levels determined by Lowry method decreased significantly in boiling group compared to other groups (p <0.001). Total protein levels in raw milk and pasteurized milk were found not to differ in terms of levels determined by Bradford method and Lowry method (p >0,05). On the other hand, total protein levels (2.26 ± 0.13 g/dl) determined by the Bradford method in boiled milk were determined to be higher than total protein levels (1.92 ± 0.09 g/dl) determined by Lowry method (p <0.05). Significant but weak negative correlations were determined between melatonin and vitamin C levels in milk with pasteurization (r =-0,114, p <0.05) and boiling process (r=-0,572, p <0.01). Positive correlations were determined between total protein levels determined by Bradford and Lowry methods in raw milk (r=0,723, p <0,01), pasteurized (r =0,838, p <0,01) and boiled (r=0,449, p <0,05) milk samples. Conclusion: It was determined that pasteurization process applied to goat milk did not change milk melatonin, total protein and vitamin C levels, and boiling process decreased total protein and vitamin C levels. Pasteurization was considered to be superior to the traditional boiling process in the bioavailability of goat milk. Before melatonin analysis was performed in milk by ELISA method, it was predicted that a pre-treatment of milk may be useful in order to separate melatonin from the protein it is bound to, thus may result in achieving more accurate results.
Aim: In this project, it was aimed to investigate the effects of pasteurization (15 seconds at 72 ºC) and boiling processes (5 minutes at 100 ºC) on goat milk melatonin, vitamin C and total protein levels. Material and Methods: The milk of 20 healthy goats (10 Aleppo, 10 Kilis goats) obtained from a private goat farm were used as materials. In April, milk was supplied from goats that returned from pasture in the morning (between 10:30 and 11:00) during routine milking. Each milk sample was divided into 3 for raw milk, for pasteurization process (15 seconds at 72 ºC) and for boiling process (5 minutes at 100 ºC). Melatonin levels in raw, pasteurized and boiled milk were determined with commercial ELISA kit, while, vitamin C and total protein levels were determined by manual spectrophotometric methods. Results: Melatonin levels in boiled milk samples (4.20 ± 0.39 pg/ml) increased (p <0.05) compared to both raw milk (3.19 ± 0.25 pg/ml) and pasteurized (3.42 ± 0.24 pg/ml) milk samples. Vitamin C levels did not differ in the pasteurization group (2.99 ± 0.16 mg/100 ml) compared to the raw milk group (3.18 ± 0.24 mg/100 ml). On the other hand, vitamin C levels obtained after boiling process (2.03 ± 0.12 mg/100 ml) were lower than that in the raw and pasteurized milk samples (p <0.001). While there was no difference between the heat treated groups in terms of total protein levels determined by Bradford method, the total protein levels determined by Lowry method decreased significantly in boiling group compared to other groups (p <0.001). Total protein levels in raw milk and pasteurized milk were found not to differ in terms of levels determined by Bradford method and Lowry method (p >0,05). On the other hand, total protein levels (2.26 ± 0.13 g/dl) determined by the Bradford method in boiled milk were determined to be higher than total protein levels (1.92 ± 0.09 g/dl) determined by Lowry method (p <0.05). Significant but weak negative correlations were determined between melatonin and vitamin C levels in milk with pasteurization (r =-0,114, p <0.05) and boiling process (r=-0,572, p <0.01). Positive correlations were determined between total protein levels determined by Bradford and Lowry methods in raw milk (r=0,723, p <0,01), pasteurized (r =0,838, p <0,01) and boiled (r=0,449, p <0,05) milk samples. Conclusion: It was determined that pasteurization process applied to goat milk did not change milk melatonin, total protein and vitamin C levels, and boiling process decreased total protein and vitamin C levels. Pasteurization was considered to be superior to the traditional boiling process in the bioavailability of goat milk. Before melatonin analysis was performed in milk by ELISA method, it was predicted that a pre-treatment of milk may be useful in order to separate melatonin from the protein it is bound to, thus may result in achieving more accurate results.
Açıklama
Anahtar Kelimeler
Biyokimya, Biochemistry ; Spor
