Frying performance of low‐linolenic acid soybean oil

Abstract

The frying performance of low-linolenic acid soybean oil from genetically modified soybeans was examined. Partially hydrogenated and unhydrogenated low-linolenic acid soybean oils were compared to two partially hydrogenated soybean frying oils. Frying experiments utilizing shoestring potatoes and fish nuggets were conducted. Frying oil performance was evaluated by measuring free fatty acid content, p-anisidine value, polar compound content, soap value, maximal foam height, polymeric material content, and Lovibond red color. The hydrogenated low-linolenic soybean oil (Hyd-LoLn) consistently had greater (P < 0.05) free fatty acid content and lower p-anisidine values and polymeric material content than did the other oils. Hyd-LoLn generally was not significantly different from the traditional oils for polar content, maximal foam height, and Lovibond red color. The low-linolenic acid soybean oil (LoLn) tended to have lower soap values and Lovibond red color scores than did the other oils. LoLn had consistently higher (P < 0.05) p-anisidine values and polymeric material content than did the other oils, and LoLn generally was not different (P < 0.05) from the traditional oils for polar content, maximal foam height, and free fatty acid.Deep-fat frying is a popular and convenient food preparation method. The high temperature, as well as the incorporation of oxygen and water, during deep-fat frying necessitate the use of a stable frying oil. Traditionally, partially hydrogenated oils have been used for frying purposes because hydrogenation increases an oil's resistance to thermal and atmospheric oxidation. However, a side effect of hydrogenation is the formation of positional and geometrical fatty acid isomers. Some studies have indicated that there may be adverse health effects due to dietary trans fatty acid consumption (1-3).A recent alternative or complement to hydrogenation is the use of oils with genetically modified fatty acid composition. High-oleic canola, safflower, and sunflower oils, as well as low-linolenic canola and soybean oils, have been developed (4). Several studies have examined the frying performance of modified oils (5-13). Warner and Mounts (8) compared frying stability of genetically modified, low-linolenic, nonhydrogenated and hydrogenated soybean and canola oils to nonhydrogenated, traditional soybean and canola oils. The modified oils had less room odor intensity; lower free fatty acid contents, polar compounds, and foam heights; fewer undesirable odors; and better food quality than the traditional oils after 5 h of frying. Mounts et al. (9) compared three lines of lowlinolenic acid soybean oil (LoLn) and traditional unhydrogenated soybean oil. However, most soybean oils used for frying purposes were partially hydrogenated. Lowering the linoleic acid content of soybean oil by breeding was beneficial for improved oil quality during cooking and frying. The flavor quality of fried food was enhanced with these oils. LoLn soybean oils were compared to traditionally unhydrogenated and partially hydrog...

Evaluation of the performance of Frying Oils using an ultrasonic technique

“…Therefore, ultrasonic velocity is a parameter which allows assessing oil quality and oil stability. Indeed, previous studies indicated that a lower linoleic acid content in soybean oil resulted in improved oil quality during cooking and frying (Tompkins, 2000). In this study, changes in the fatty acid profile of oils during frying are basically among the unsaturated fatty acids, whereas the saturated fatty acids are slightly increased.…”

Comportamento dos óleos de girassol, soja e milho em frituras de produto cárneo empanado pré-frito congelado

“…Os ácidos graxos livres são moderadamente voláteis e uma quantidade desconhecida é perdida durante o aquecimento. Níveis moderados de ácidos graxos livres parecem não estar relacionados com a qualidade inferior do alimento e os ácidos graxos livres podem sofrer oxidação e serem convertidos em outros produtos que não são medidos por métodos de titulação (TOMPKINS & PERKINS, 2000).…”

Effect of Deep-Fat Frying on Physicochemical Properties of Rice Bran Oil Blends

“…This was consistent with findings from previous studies showing that the amounts of polymers increased with an increase in the number of fryings and the frying temperature. These polymers cause higher oil absorption of foods [17]. After third frying, the highest absorption of RBO+SO and the lowest absorption of RBO+GO in both ratios could be due to the presence of linoleic acid and oleic acid respectively.…”

“…After second frying absorption of all the blended oils (70: 30, 80:20) increased significantly (p≤0.05) whereas after third frying there was a significant (p≤0.05) decline in the absorption rate except in the RBO+SO in the both ratios. As the number of fryings and the frying temperature increase, the amounts of polymers increased [17]. Polymers cause higher oil absorption of foods and the oil rich in linoleic acid is more easily polymerized during deep-fat frying than the oil rich in oleic acid [18].…”