ALTERNATIF UJI KUALITAS MINYAK GORENG BERDASARKAN PERUBAHAN SUDUT POLARISASI CAHAYA

Abstract

Quality of cooking oil before and after heated has been tested. The parameter of quality was based on electrooptis characteristic of cooking oil. In this examination, it was used three different brands of cooking oils. The samples were heated in the time interval between 0-120 minutes. The electrooptics characteristic was determined by measuring the change of polarization angle of light as it passed through the oil when it was applied by external electric field. The field was produced by two parallel plates connected to different potential between 0-9kV. The light source was diode laser at (l =650 nm) and (l =532 nm). The quality of oil was then determined by average polarization angle per potential i.e. /V. Based on the result of observation, the cooking oil before heated had smaller change of light polarization angle than after heated. Therefore it was used to determine the parameter of quality cooking oil. The smallest rotate electrooptic capability leads to a good quality parameter. In 2 hours heated, with (l =532 nm), cooking oil A = (4,44± 0,24) x 10-4 o/kV, B = (5,44± 0,22) x 10-4 o/kV and C = (6,11± 0,30) x 10-4 o/kV.