Influence of a Screw Press Type and Pressing Parameters of Hemp Seeds of the Variety Santhica 70 on the Oil Yield and Stabilization with Antioxidants and Synergists

U ovom diplomskom radu ispitivan je utjecaj procesnih parametara prešanja na iskorištenje hladno prešanog konopljinovog ulja. Prešanje sjemenki konoplje provedeno je na kontinuiranoj pužnoj preši u laboratoriju. Tijekom proizvodnje ulja mijenjali su se procesni parametri: veličina otvora glave preše, temperatura glave preše te frekvencija elektromotora. Finalno hladno prešano ulje dobilo se nakon provedene sedimentacije i vakuum filtracije. U proizvedenom ulju određeni su osnovni parametri kvalitete: peroksidni broj, slobodne masne kiseline, vlaga te udio netopljivih nečistoća. Na proizvedenom hladno prešanom ulju ispitan je i utjecaj dodatka antioksidanasa i sinergista na oksidacijsku stabilnost ulja Schaal Oven testom pri 63 °C. Od antioksidanasa korišteni su ekstrakt ružmarina, ekstrakt kadulje, ekstrakt zelenog čaja, mješavina tokoferola, kafeinska kiselina, a od sinergista askorbinska i limunska kiselina. Rezultati su pokazali da promjena procesnih parametara prešanja utječe na iskorištenje ulja, a dodaci antioksidanasa i sinergista doprinose stabilizaciji i održivosti ulja. In this thesis, the influence of process parameters on the use of cold-pressed hemp oil was investigated. The pressing of hemp seeds was carried out on a continuous screw press in the laboratory. During oil production, the process parameters changed: the size of the press head opening, the temperature of the press head and the frequency of the electric motor. The final cold-pressed oil was obtained after sedimentation and vacuum filtration. The basic quality parameters of cold-pressed oil are also determined in the oil: peroxide value, free fatty acids, moisture and the proportion of insoluble impurities. The influence of the addition of antioxidants and synergists on oxidizing oils was also tested on the produced cold-pressed oil using the oven stability test at 63 °C. Rosemary extract, sage, green tea extract, tocopherol mixture, caffeic acid are used as antioxidants, and ascorbic and citric acid are used as synergists. The results showed that the change in process parameters affects the utilization of the oil, and the addition of antioxidants and synergists contribute to the stabilization and sustainability of the oil.