Effect of Process Conditions on Sandbox Seed Oil Yield by Mechanical Expression: A Response Surface Approach

Abstract

Cost of solvent oil extraction methods has made mechanical oil expression a desirable alternative. The effect of process variables on mechanical oil expression from sandbox seed was studied. The experimental design used for the study was a 52 Central Composite Rotatable Design of Response Surface Methodology. Experimental factors considered were: moisture content, roasting temperature, roasting time, expression pressure and expression time. Results obtained were analyzed at α0.05. The oil yield from the sandbox seed ranged from 16.38-38.68%, and was increased at processing variable ranges of (4.0-8.0%) moisture content, (80.0-90.0oC) roasting temperature, (5.0-15.0%) roasting time, (15.0-20.0 MPa) expression pressure and (6.0-8.0 min) extraction time. The maximum oil yield of 38.68% was obtained at the processing conditions of 6% moisture content, 85 oC roasting temperature, 15 min roasting time, expression pressure of 20 MPa and 8 min pressing time. Model equation relating the process variables to oil yield was developed. Coefficient of determination (R2) relating the process was 0.8908. The result showed that moisture content, roasting time, expression pressure and expression time had a significant influence on the sandbox oil yield. The results obtained in this study can serve for process and equipment designs for oil extraction from sandbox and other oilseeds and nuts.

Troškovi metoda ekstrakcije ulja učinili su mehaničku ekspresiju ulja poželjnom alternativom. Izvršeno je ispitivanje uticaja obrade promenljivih parametara na mehaničku izdvajanje ulja semena Sendbox (Hura crepitans Linn.). Eksperimentalni dizajn korišćen za ovu studiju ima 52 Centralnu kompozitnu rotabilnu površinsku dizajn metodologiju . Eksperimentalni faktori koji su uzeti u obzir bili su: sadržaj vlage, temperatura, i vreme zagrevanja, pritisak izlaganja i vreme ekspresije. Dizajn metodologije površinske reakcije usvojen za eksperiment je α0.05. Najveći prinos ulja semena Sendbox (Hura crepitans Linn.), povećan je, i kretao se u rasponu od 16,38 do 38,68% kod sadržaja vlage od 4,0 do 8,0%; temperature zagrevanja od 80,0 do 100,0oC; vremena zagrevanja od 5,0 do 15,0 min; pritiska izdvajanja od 15,0 do 20,0 MPa , za vreme ekstrakcije od 6.0 do 8.0 min. Maksimalni prinos ulja od 38,68% je dobijen u uslovima prerade kod 6% sadržaja vlage semena, temperature zagrevanja 85oC, sa 15 minuta zagrevanja i ekspresijskog pritiska od 20 MPa, i 8 minuta izdvajanja ili presovanja. Razvijen je model jednačine koja povezuje promenljive procesa sa prinosom ulja. Koeficijent determinacije (R2) , koji se odnosi na ovaj process, bio je 0,8908. Rezultati pokazuju da sadržaj vlage, vreme zagrevanja, pritisak izdvajanja i vreme ekspresije imaju značajan uticaj na prinos ulja semena Sendbox (Hura crepitans Linn.). Rezultati dobijeni u ovoj studiji mogu poslužiti za dizajn procesa i opreme za ekstrakciju ulja iz semenki Senbox i drugih semenki ulja i orašastih plodova.