Palm oil is the second largest edible vegetable oil in terms of global production. It has been established that palm oil contains high oxidative stability and high levels of natural antioxidants, such as β-carotene, tocopherols and tocotrienols.
Studies regarding the negative effects of microwave heating and conventional heating has surfaced from time to time.
In a study conducted at University Teknologi MARA to evaluate carotene and the antibacterial effects of microwave heated and conventional heated red palm oil (RPO) and discovered that heating red palm oil reduced its carotene levels but microwave heated red palm oil retained higher carotene content as compared to conventionally heated red palm oil.
This study focussed on the effects of heat on carotene levels and the it revealed the presence of higher carotene content in microwave heated red palm oil as compared to conventionally heated red palm oil due to the different heating mechanism.
The study also focussed on the bacteria, Escherichia coli’s growth. Both fresh and heated red palm oil did not exhibit inhibitory effects on the Escherichia coli bacterial growth. It has been established that the reheating of oil in the presence of oxygen is associated with chemical reactions such as hydrolysis, oxidation and polymerization.
These chemical reactions generate highly reactive molecules that potentially cause deleterious effects. However, the result showed that the repeatedly heated RPO samples were not capable of affecting the bacterial growth. Thus it was likely that the bacteria were not susceptible to such environments.
The study demonstrated that both thermal treatments can reduce the carotene content in red palm oil. However, microwave heating retains higher carotene content in red palm oil as compared to conventional heating.
The study recommends that, conventional heating be replaced with microwave heating for a healthy red palm oil diet.
Meanwhile, commercial red palm oil is not effective against bacteria such as E. coli. However, it remains well accepted that the red palm oil offers various promising potentials to combat diseases.
Our study provides an insight into the impact of different reheating methods on carotene content in red palm oil. The paper was presented at the 2012 IEEE Symposium on Humanities, Science and Engineering Research in Kuala Lumpur, Malaysia.
M.F. Z. Raja Yahya,
Faculty of Applied Sciences
Universiti Teknologi MARA,
40450 Shah Alam Selangor MALAYSIA
email: [email protected]