The effect of processing parameters on the physicochemical properties of oil from roselle seed

Abstract

PurposeThe study aimed to focus on the effect of the processing parameters on the physicochemical properties of oil from roselle seed.Design/methodology/approachFine and coarse samples of the ground roselle seeds were conditioned to the moisture contents of 4.4‐10.4 per cent and 5.14‐11.14 per cent. Oil was expressed at applied pressures of 15‐37.5 MPa with 7.5 MPa interval using hydraulic oil extractor for between 10‐40 min. at increment of 10 min. and at the heating temperatures of 80, 90, 100 and 110°C over a period of 15‐30 min. at an increment of 5 min. All the physicochemical properties were determined using AOAC and AOCS methods [AOAC, 1984; AOCS, 1994].FindingsThe free fatty acid, peroxide values and the colour intensity of the oil were affected by the processing parameters; while saponification value, viscosity, specific gravity, refractive index and the iodine value of the oil were not affected by the expression parameters.Originality/valueProcessing parameters were found to affect the quality attributes of free fatty acid, peroxide values and the colour intensity of the oil.