Comparison of the frying stability of standard palm olein and special quality palm olein.

摘要

The main aim of this study was to investigate the stability of standard palm olein (SPOo) and special quality palm olein (SQPOo) under continuous frying conditions. The rate of free fatty acid (FFA) formation was slightly higher for SPOo than SQPOo during 56 h of frying. An equilibrium state was reached at around 40 h for SPOo and 32 h for SQPOo, whereby FFA contents varied within a narrow range of 0.30-0.32 and 0.22-0.25%, respectively. Smoke point of SPOo and SQPOo progressively dropped from 212 to 184 degrees C and from 227 to 191 degrees C, respectively. Tocol contents of SPOo and SQPOo declined from 550 to 273 mg/kg and from 720 to 447 mg/kg, respectively, after 56 h of frying. Oxidative stability of both oils decreased after successive frying periods. Induction time of SPOo dropped from 22.3 to 14.9 h while that of SQPOo decreased from 25.5 to 18.3 h. Polar and polymer compounds increased as frying progressed. The SPOo had higher levels of polar compounds, averaging 11.8%, compared to the 10.2% in SQPOo. However, SPOo had lower levels of polymer compounds compared to SQPOo, averaging 2.1 and 2.5%, respectively. Hence, this study confirms that frying performance using SPOo is comparable to that of SQPOo under conditions used in industrial production of snack foods (e.g. potato chips).