Study on the oxidative rate and prooxidant activity of free fatty acids

Abstract

Oleic, linoleic and linolenic acids were autoxidized more rapidly than their corresponding methyl esters. Addition of stearic acid accelerated the rate of autoxidation of methyl linoleate and the decomposition of methyl linoleate hydroperoxides. Therefore, the higher oxidative rate of FFA's than their methyl esters could be due to the catalytic effect of the carboxyl groups on the formation of free radicals by the decomposition of hydroperoxides. Addition of stearic acid also accelerated the oxidative rate of soybean oil. This result suggests that particular attention should be paid to the FFA content that affects the oxidative stability of oils.

Influence of Button mushroom (Agaricus bisporus) on quality and refrigerated storage stability of patties prepared from sutchi catfish (Pangasius hypophthalmus)

“…Pacheco-Aguilar et al (2000) have reported that, lipases and phospholipases hydrolyze glycerol-fatty acid to release free fatty acids. Free fatty acids have been shown to oxidize faster than their triacylglycerols (Labuza et al 1969;Yanishlieva-Maslarova 1985) and faster than ethyl and methyl esters (Miyashita and Takagi 1986). Thus the free fatty acids exert a pro-oxidative effect.…”

“…Thus the free fatty acids exert a pro-oxidative effect. This effect is due to complex formation between hydroperoxides and carboxyl groups through a hydrogen bond, which results in an accelerated decomposition of hydroperoxides into free radicals (Miyashita and Takagi 1986). Bimbo (1998) has suggested a maximum acceptable value of 5 % as quality specifications for crude fish oil.…”

Lipid hydrolysis and oxidation in farmed gilthead seabream (<i>Sparus aurata</i>) slaughtered and chilled under different icing conditions

“…While the formation of FFA itself does not lead to nutritional losses, its assessment is deemed important when considering the development of rancidity. Thus, a pro-oxidant effect of FFA on lipid matter has been proposed and explained on the basis of a catalytic effect of the carboxyl group on the formation of free radicals by the decomposition of hydroperoxides (Miyashita and Takagi, 1986;Aubourg, 2001). In addition, FFA are known to oxidize faster than higher-molecular weight lipid classes (namely, triglycerides and phospholipids) by providing a greater accessibility (lower steric hindrance) to oxygen and other prooxidant molecules (Labuza, 1971).…”

Lipid damage detection during the frozen storage of an underutilized fish species

“…Formation of FFA itself does not lead to nutritional losses. However, it has been proven that accumulation of FFA in frozen fish is related to some extent with lack of acceptability of frozen fish, because FFA are known to cause texture deterioration by interacting with proteins (Mackie, 1993;Sotelo et al, 1995) and have shown to be strongly interrelated with lipid oxidation (Miyashita and Takagi, 1986;Han and Liston, 1988).…”