Characterisation and research of the milk quality in Krk cheese manufacturing

U proizvodnji sira od presudne je važnosti fizikalno-kemijski sastav i higijenska kvaliteta mlijeka. Tijekom 2007. godine provedeno je istraživanje proizvodnih osobina i kvalitete mlijeka krčkih ovaca, te je opisan tehnološki postupak proizvodnje i analiziran fizikalno-kemijski sastav krčkog sira. Kontrola mliječnosti provedena je prema AT metodi. Analize kemijskog sastava provedene su infracrvenom spektrometrijom, a higijenske kvalitete mlijeka fluoro-opto-elektronskom metodom, odnosno metodom protočne citometrije. U laktaciji od 160 dana ovce su u prosjeku proizvele 108 kg mlijeka (38 kg u dojnom, a 70 kg u muznom razdoblju) s 5,67 kg mliječne masti i 4,12 kg proteina. Mlijeko je u prosjeku sadržavalo: 19,49 % suhe tvari, 8,29 % mliječne masti, 5,99 % proteina, 4,45 % laktoze i 11,32 % suhe tvari bez masti. Mužnja je imala značajan utjecaj na: dnevnu količinu mlijeka, udio suhe tvari i mliječne masti, točku ledišta mlijeka i higijensku kvalitetu mlijeka. Između proizvodnih osobina ovaca i pojedinih pokazatelja kvalitete mlijeka utvrđeni su značajni koeficijenti korelacija. Na osnovu rezultata istraživanja mogu se predložiti vrijednosti fizikalno-kemijskog sastava, mikrobiološke i senzorne kvalitete mlijeka i krčkog sira, potrebnih u standardizaciji proizvodnje.Physical-chemical composition and hygienic quality of milk are of crucial importance in cheese manufacturing. During 2007, a research was carried out with the aim to investigate manufacturing features and milk quality of Krk sheep and to describe technological procedure of manufacture and physicalchemical composition of Krk cheese. The milking capacity was checked according to AT method. Chemical composition was analyzed by infrared spectrometry and hygienic milk quality by fluoro-opto-electronic method, i.e. flow cytometry method. In 160 days of lactation, sheep produced in average 108 kg of milk (38 kg in lactating and 70 kg in milking period), 5.67 kg of milk fat and 4.12 kg of proteins. In the average, the milk contained: 19.49 % of dry matter, 8.29 % of milk fat, 5.99 % of proteins, 4.45 % of lactose and 11.32 % of dry matter without fat. Milking had a significant influence on: daily milk quantity, dry matter and milk fat share, milk freezing point and hygienic milk quality (log10MO and log10BSS). Significant correlation coefficients were determined between manufacturing features of sheep and certain milk quality indicators. Based on the research results, values of physical-chemical composition, microbiological and sensory milk and cheese quality can be suggested, necessary in standardization of technological manufacturing procedure of Krk cheese