کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1191063 | 963547 | 2006 | 6 صفحه PDF | دانلود رایگان |

A method for the large-scale isolation of β-casein from renneted skim milk was developed. The curd from renneted skim milk was dispersed in hot (⩾70 °C) water to inactivate residual chymosin. The heated curd was subsequently recovered by centrifugation, resuspended in water and incubated at 5 °C, during which β-casein dissociated from the curd; the suspension was centrifuged and the aqueous phase lyophilised. The isolated protein consisted mainly of β-casein, containing a minor amount of γ-caseins and traces of other caseins. Unless chymosin was fully inactivated by heating, some β-casein was hydrolysed at the Leu192–Tyr193 bond. The yield of β-casein increased with incubation time, up to ∼20% of the β-casein present in the milk after 24 h at 5 °C. Reducing milk pH to 5.5 or 6.0, prior to renneting, caused a high level of contamination with αs-caseins. This isolation procedure can be easily scaled-up to an industrial process and the β-casein-depleted curd may be used for the manufacture of rennet casein or processed cheese.
Journal: Food Chemistry - Volume 99, Issue 1, 2006, Pages 45–50