Shallow-frying oils show fortification potential: Unilever study
Over 60 per cent of vitamin A or vitamin D in a fortified margarine was still present following a shallow frying process, according to findings from Karel Hrncirik from the Fat Technology unit with Unilever R&D Vlaardingen.
“Based on the results of simulated shallow frying it can be concluded that consumers will benefit from daily usage of cooking products high in both fat-soluble vitamins and essential polyunsaturated fatty acids, as the nutrients absorbed with the oil into the cooked food will contribute significantly to the dietary intake of these nutrients,” wrote Hrncirik in Lipid Technology.
According to background information in the article, oils and fats for frying are not seen as suitable vehicles for nutritional fortification since the frying process is associated with the loss and degradation of vitamins and essential fatty acids.
“These assumptions are mainly based on data obtained from studying deep-frying that are of a very limited use for the evaluation of cooking margarines,” explained Hrncirik, who’s new findings indicated that such offer an avenue for nutritional fortification.
Hrncirik investigated the stability of various fat-soluble vitamins, including vitamins A, D, and E, and the plant-derived omega-3 fatty acid alpha-linolenic acid (ALA) in liquid margarine that is subjected to a shallow frying process at 180 Celsius.
Results showed that recover of vitamins A and D was over 60 per cent, while vitamin E recover was slightly less. ALA levels were virtually unaffected by the shallow frying, with a loss of less than 2 per cent.
Importantly, “the formation of fatty acid trans-isomers was not noticeable”, wrote Hrncirik.
“Unlike deep-frying, during which the oil is repeatedly exposed to frying cycles for a long time (tens of hours), shallow-frying is a short process (just a few minutes) with no re-use of the oil and it is generally accepted that the degradation of fatty acids is not a concern,” he wrote. “A lack of the temperature control, however, poses a risk of overheating of the frying medium if the shallow frying procedure is carried out in an inappropriate manner.”
Source: Lipid Technology
Volume 22, Issue 5, Pages: 107-109
“Stability of fat-soluble vitamins and PUFA in simulated shallow-frying”
Authors: K. Hrncirik