Influence of curd particles drying temperature on the composition of curd made of milk in which co aggregates were formed

Abstract

The influence of different drying temperatures of curd particles in order to obtain curd particles with chemical composition characteristic for Dutch-type semi-hard cheeses was investigated. The experiments were performed with heat-treated milk at 87ºC for 10 minutes to induce chemical interaction between casein and serum proteins and to form the co-called co aggregates. The curd particles were dried at 42ºC and 45ºC for 60 minutes and two types of curd, named curd A and curd B were formed afterwards. The results of the experiments showed that the used temperatures had no significant influence on chemical composition of the curd. The average total solids of curd A was 49.09%, moisture in fat free basis (MFFB) 68.78% protein content 22.23%, lactose content 1.55%, ash 1.98%, titratable acidity 71.700T and pH 6.22. On the other side, the average values for curd B were 49.40%, 68.58%, 22.74%, 1.47%, 1.94%, 75.920T and 6.07, respectively. The use of different drying temperatures, as well as the other treatments (pressing, salting and ripening) provide conditions for semihard cheese producing, with the chemical composition similar to the Dutch-type semihard cheese prepared according to the traditional method.

U radu je ispitivan uticaj različitih temperatura sušenja sirnog zrna sa ciljem dobijanja sirnog zrna koje je po sastavu karakteristično za polutvrde sireve holandskog tipa. U ogledima je korišćeno mleko kod kojeg je prethodnom termičkom obradom na 870C u toku 10 minuta, obrazovan hemijski kompleks između kazeina i serum proteina, poznatih u literaturi kao koagregati proteina mleka. Sušenje sirnog zrna izvršeno je na temperaturi od 420C, i nakon toga obrazovana sirna gruda A, i na temperaturi od 450C (sirna gruda B) u vremenu od 60 minuta. Rezultati istraživanja su pokazali da primenjene temperature sušenja nisu imale značajnijeg uticaja na hemijski sastav dobijene sirne grude. Prosečan sadržaj suve materije kod sirne grude A iznosio je 49.09%, sadržaj vode u bezmasnoj materiji sira (VBMS) 68.78% proteina 22.23%, laktoze 1.55%, pepela 1.98%, titraciona kiselost 71.700T i pH 6.22. Prosečan sadržaj suve materije kod sirne grude B iznosio je 49.40% vode u bezmasnoj materiji sira 68.58%, proteina 22.74%, laktoze 1.47% pepela 1.94%, titraciona kiselost 75.920T i pH 6.07. Primenom različitih temperatura sušenja sirnog zrna (42ºC i 45ºC), kao i daljim tehnološkim operacijama (presovanje, soljenje i zrenje) obezbeđeni su uslovi za dobijanje sira koji po hemijskom sastavu odgovara polutvrdim sirevima holandskog tipa, proizvedenim na tradicionalan način.