The influence of process parameters on the yield and quality of cold-pressed pumpkin seed oil

U ovom diplomskom radu istraživan je utjecaj procesnih parametara prešanja bučine koštice (golice) na efikasnost proizvodnje hladno prešanog bučinog ulja te na njegovu kvalitetu. Prešanje bučine koštice provedeno je na laboratorijskoj pužnoj preši za proizvodnju hladno prešanih biljnih ulja. Prešanjem koštice došli smo do tri proizvoda: sirovo ulje, uljni talog i pogača. Tijekom samog procesa prešanja mjenjali su se procesni parametri: temperatura glave preše, brzina pužnice i nastavak za izlaz pogače. Nakon završetka procesa prešanja provedeno je prirodno taloženje dobivenog sirovog ulja te centrifugiranje. Primjenjujući standardne metode određeni su parametri kvalitete ulja: peroksidni broj, slobodne masne kiseline, udio netopljivih nečistoća, udio vlage i hlapljivih tvari. Za određivanje efikasnosti proizvodnje ulja provedeno je ispitivanje udjela ulja u koštici i pogači metodom po Soxhlet-u. Rezultati pokazuju da je primjenom veće temperature glave preše tijekom prešanja bilo skorištenje ulja veće. Upotrebom nastavka manjeg promjera za izlaz pogače dolazi do porasta tlaka u preši, a samim time i do većeg iskorištenja sirovog ulja.The goal of this diploma work was exploring the influence of the process parameters in cold-pressing of the pumpkin seeds, on the efficiency of the production of the pumpkin seed oil and it's quality. Cold-pressing of the pumpkin seed was done on a laboratory press used for the production of the cold-pressed vegetable oils. In the process of cold-pressing we've gained three products: unpurified crude oil, oil sludge and cake of. During the pressing process, the parameters were changed: the temperature of head press, the frequency, and output cake thickness. After the pressing, the produced raw oil was left to naturally settle and was afterwards centrifugated. Applying the standard procedures, the parameters of the oil quality were defined: peroxide number, free fatty acids, proportion of insoluble impurities, quantity of moisture and evaporable substances. To determine the efficiency of production we conducted behind oil expeller method of Soxhlet. Applying higher temperatures head presses for molding a greater yield of oil. Using the extension of a smaller diameter for the cake comes out to increase the pressure in the press, and thus a higher yield of the crude oil. Frequency during compression affects the yield of oil