The influence of different milk composition on the properties of kefir

U radu je proučavan utjecaj različitog sastava mlijeka na tijek fermentacije i organoleptička svojstva kefira. Za proizvodnju kefira upotrijebljeno je mlijeko s dodatkom mlijeka u prahu i bez njega te mješavine mlijeka sa 20% i 30% ultrafiltrirane demineralizirane sirutke. Također je korišteno i ultrafiltrirane obrano mlijeko (UF-mlijeko) s različitim udjelom proteina. Uzorci mlijeka podešeni su na pH-vrijednost 6,6-6,7, pasterizirani 5 min. (90° C), ohlađeni (25 °C), cijepljeni sa 3% matične kefirne kulture te inkubirani (23 °C) do pojave koaguluma. Proizvedeni uzorci kefira pohranjeni su jedan dan pri temperaturi od 8 °C određena je pH-vrijednost i titracijska kiselost te organoleptička svojstva kefira. Tijekom čuvanja uzoraka kefira u hladnjaku tri je dana praćena pH-vrijednost i promjena organoleptičkih svojstava kefira.The influence of different milk composition on fermentation and organoleptic properties of kefir samples was investigated. In experimental kefir samples production milk was used with and without addition of dried milk and also mixture of milk with added 20 and 30% of ultrafiltrated demineralized whey. Skim milk concentrated using ultrafiltration (UF-milk) to different percentage of proteins was used as well. The pH value of the reference milk and pH values of experimental milk samples were adjusted to pH = 6.6-6.7, pasteurized 5 min (90 °C), cooled to 25 °C, inoculated with 3% of kefir culture and incubated (23 °C), until coagulation. After 1 day\u27s storage of kefir samples (8\u27C) actual and titratable acidity and organoleptic properties of kefir were determined. During 3 day\u27s storage of kefir samples (8 °C), changes of pH values and organoleptic properties of samples were also determined