Tarmizi Azmil Haizam Ahmad, Lin Siew Wai
Analytical and Quality Development Unit, Malaysian Palm Oil Board, Persiaran Institusi, Selangor, Malaysia.
J Oleo Sci. 2008;57(12):639-48. doi: 10.5650/jos.57.639.
Extending the frying-life of oils is of commercial and economic importance. Due to this fact, assessment on the thermal stability of frying oils could provide considerable savings to the food processors. In this study, the physico-chemical properties of five palm products mainly palm oil, single-fractionated palm olein, double-fractionated palm olein, red palm olein and palm-based shortening during 80 hours of heating at 180 degrees C were investigated. Heating properties of these products were then compared with that of high oleic sunflower oil, which was used as reference oil. The indices applied in evaluating the quality changes of oils were free fatty acid, smoke point, p-anisidine value, tocols, polar and polymer compounds. Three palm products i.e. palm oil, single-fractionated palm olein and double-fractionated palm olein were identified to be the most stable in terms of lower formation of free fatty acid, polar and polymer compounds as well as preserving higher smoke point and tocols content compared to the other three oils. The low intensity of hydrolytic and oxidative changes due to prolonged heating, suggests that these palm products are inherently suitable for frying purposes.
延长油脂的油炸寿命具有商业和经济重要性。鉴于此，对油炸油热稳定性的评估可为食品加工商节省可观的成本。在本研究中，研究了五种棕榈产品（主要是棕榈油、单分提棕榈油精、双分提棕榈油精、红棕榈油精和棕榈基起酥油）在180℃下加热80小时期间的物理化学性质。然后将这些产品的加热特性与用作参考油的高油酸向日葵油进行比较。用于评估油脂质量变化的指标有游离脂肪酸、烟点、对茴香胺值、生育酚、极性化合物和聚合物化合物。与其他三种油相比，三种棕榈产品，即棕榈油、单分提棕榈油精和双分提棕榈油精，在游离脂肪酸、极性化合物和聚合物化合物形成较少以及保持较高烟点和生育酚含量方面被确定为最稳定的。长时间加热导致的水解和氧化变化强度较低，表明这些棕榈产品本质上适合用于油炸。
