Raffaele Romano, Anella Giordano, Simona Vitiello, Laura Le Grottaglie, and Salvatore Spagna Musso
Abstract: Deep-fat frying is an important method of food preparation in which foods are immersed in hot oil. Repeated use of frying oils is a common practice, and in the presence of atmospheric oxygen it produces various undesirable reactions in used oils. Stable frying oils usually require low linolenic acid (LnA < 3%), increased oleic acid (OA > 40%), and decreased linoleic acid (LA < 50%). The aim of this study was to establish the behavior of palm superolein (PSO) (OA 45%; LA 12.5%; LnA 0.2%) and olive oil (OO) during repeated, discontinuous deep frying of French fries. The behavior of the oils under controlled heating conditions was also studied by maintaining all of the process variables the same as those in deep frying, except that there was no food in the oil. The PSO selected to be tested in this study may represent an alternative to OO as a frying medium. Although PSO presented a faster increase in some oxidation indices, such as free fatty acid and total polar compounds, for other indicators, PSO showed better behavior than OO (less formation of C8:0 and lower peroxide value).
Source : Journal of Food Science Volume 77, Issue 5, pages C519–C531, May 2012
The good performance of palm super olein in frying studies has been reported by many. In this particular study, frying performance of palm super olein was compared to that of olive oil and virgin olive oil. The overall result is in favour of palm oil as compared to olive. Among the parameters used for comparison in this study are oil absorbtion, free fatty acid (FFA), peroxide value (PV), total polar compound (TPC) among others. And palm super olein showed better results for most of the parameters analysed.
Another positive aspect of palm super olein in this study is that it showed lower formation of the sulfide compound as compared to olive oil. This is an indication that palm super olein provided higher chemical stability compared to olive oil.
This study also acknowledges that palm oil is more widely and cheaply available compared to olive. This is an important factor especially for the food manufacturing sector which must have an easy and consistent access to their raw ingredients for their product manufacturing and at reasonable prices. Similarly, for the general consumers, consistent access and supply of palm oil also means price stability to a certain degree.
Apart from frying oil performance, another important factor which should have been taken into consideration in this study is the taste of the resulting fried foods. Unlike palm oil, olive has a very distinct taste and aroma and this taste does not blend very well with many types of fried foods except for foods which are unique to Mediterranean cuisines. Therefore, its application is rather limited especially in the food manufacturing industry. On the other hand, palm oil as we know it has a bland taste and aroma. This characteristic of palm oil is very important because it allows for the fried food to carrys its natural flavour during the frying process. This is one of the main reasons many of the industrial fried ramen noodles uses palm oil as their frying medium.