Detection and evaluation of bovine milk in ovine - caprine and domestic buffalo milk and cheese by isoelectric focusing
1999
Simoni, M.
英语. The fraudulent addition of bovine milk to that of sheep, goat and domestic buffalo milk destined to be transformed into dairy products is a very frequent practice brought about by the undoubtable economic profits. The method described in this work, for the detection of contaminating bovine milk, is based on an in voto specific hydrolysis of beta casein into gamma-casein by the addition of bovine plasmin. Separation of gamma2-caseins from different species by polyacrylamide gel isoelectric focusing was performed in a pH gradient of 5.0-7.7. This is followed by densitometric evaluation of the electrophoretic bands. This method was used on milk samples. Linear regression analysis was carried out to quantify the amount of bovine milk present, this analysis was equilibrated by measuring milk samples from various species containing known amounts of bovine milk. The limit of detection for bovine milk in the mixtures sampled was approximately 0.5% by volume. This method has been also applied to cheese samples bought in various commercial outlets: 85 cheese samples, labelled as being made of pure sheep, goat or domestic buffalo milk, were analysed and bovine milk was found in 40 of them (47.1%)
显示更多 [+] 显示较少 [-]意大利语. E' stata utilizzata una metodica che si basa sulla separazione delle gamma2-caseine delle diverse specie mediante localizzazione isoelettrica su gel di poliacrilamide in presenza di un gradiente di pH 5-7,7 e sulla successiva analisi densitometrica delle bande elettroforetiche. La metodica, la cui sensibilita' e' risultata essere compresa tra lo 0,5% e l'1%, e' stata applicata a campioni di formaggio acquistati sul mercato: sono stati analizzati 85 campioni, dichiarati puri di pecora, capra o bufala, e in 40 di essi (47,1%) e' stata accertata la presenza di latte bovino
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