Physical and chemical characteristics of stearin and olein obtained by dry fractionation of milk fat

Frakciona kristalizacija ja termomehanički postupak koji omogućuje razdvajanje triglicerida po stupnju nezasićenosti. Ovaj tehnološki postupak u industriji ulja koristi se za dobijanje raznih tipova namjenskih masti. U radu je izvršeno frakcioniranje jednog uzorka mliječne masti iz otopine tzv. direktnim postupkom. Frakciona kristalizacija rađena je u vertikalnom laboratorijskom kristalizotoru sporohodnom miješalicom (16 o/min). Rastopljena mliječna mast temperature 60 °C je kontrolirano i polagano hlađena po određenom temperaturno-vremenskom, režimu od 24, 25 i 26 °C. U toku procesa frakcioniranja iskristalizirana frakcija triglicerida s višom točkom topljenja (stearin) odvajana je od tekuće frakcije (oleina) filtracijom na vakuumu. Kristalizacija, procjena kvalitete i mogućnosti primjene dobijenih frakcija vršene su određivanjem točke kapanja, točke očvršćavanja i sadržajem čvrstih triglicerida.Fractional crystalization is known as thermo-mechanical procedure that enables separation of triglicerides according to the degree of unsaturation. This technological procedure is used in oil industry for the production of various types of special fats. This paper reviews the investigations on the application of the method of dry fractionation. Fractional crystalization has been carried out in vertical laboratory crystalizer with slow rotational mixer (16 r.p.m.). Melted milk fat, at the temperature od 60 °C has been slowly and under controlled conditions cooled according to predetermined temperature and time regimes up to 24, 25 and 26 °C. In the course of the procedure of fractionation, the obtained crystalized fraction of triglicerides with a higher melting point (stearin) has been separated from liquid phase (olein) by vacuum filtration. Characterization, quality evaluation and possibilites for application, for the obtained fractions, have been carried out by the determination of dropping point, solidification point and solid fat index