Lipid-modifying enzymes in oat and faba bean

Abstract

The aim was to study lipase, lipoxygenase (LOX) and peroxygenase (POX) activities in oat and faba bean samples to be able to evaluate their potential in formation of lipid-derived off-flavours. Lipase and LOX activities were measured by spectroscopy, and POX activities via the formation of epoxides. An ultra-high performance liquid chromatography method was developed to study the formation of fatty acid epoxides. The epoxides of esters were measured by gas chromatography. Mass spectroscopy was used to verify the identity of the epoxides. Both oat and faba bean possessed high lipase activities. In faba bean, LOX catalysed the formation of hydroperoxides, whose break-down products are the likely cause of off-flavours. Since oat had low LOX activity, autoxidation is needed to initiate lipid oxidation. Oat had high POX activity, which is able to convert hydroperoxides to epoxy and hydroxy fatty acids that could contribute significantly to off-flavours. POX activity in the faba bean was low. Thus, in faba bean volatile lipid oxidation products could rapidly be formed by LOX, whereas in oat reactions are slower due to the need of autoxidation prior to further reactions.

Fava bean (Vicia faba L.) for food applications: From seed to ingredient processing and its effect on functional properties, antinutritional factors, flavor, and color

“…Dehulling and milling reportedly boost the formation of aldehydes in V. faba by increasing the total surface area and prompting the exposition of lipids to air (Akkad et al., 2019). V. faba flour exhibits high LOX activity (0.219 to 0.330 mmol/min/g), which could increase the potential for oxidative reactions and consequent formation of deleterious flavor notes in food preparations with high amounts of lipids (Yang, Piironen, & Lampi, 2017). V. faba seeds have been reported to contain two type‐II isoenzymes: broad bean lipoxygenase‐1, which produces ketodienes and both 9‐ and 13‐hydroperoxides, and broad bean lipoxygenase‐2, originating predominantly 13‐hydroperoxides (Clemente, Olías, & Olías, 2000; Eskin & Henderson, 1974).…”

Potential of faba bean lipase and lipoxygenase to promote formation of volatile lipid oxidation products in food models

“…To measure the optimal pH of faba bean lipase activity, a spectrophotometric method using p-NPB as the substrate was used (Yang et al, 2017). To compare the effect of the size of the acyl moiety on the lipase activity, p-NPP was also used as a substrate.…”

“…Thus, hydrolysis of acyl lipids to FFAs is considered a prerequisite for the LOX pathway. The faba bean is known to possess lipase (triacylglycerol acylhydrolase, EC 3.1.1.3) activity (Dundas, Henderson, & Eskin, 1978;Yang, Piironen, & Lampi, 2017), but no studies have shown its activity in food systems.…”

Triacylglycerol‐Rich Oils of Marine Origin are Optimal Nutrients for Induction of Polyunsaturated Docosahexaenoic Acid Ester of Hydroxy Linoleic Acid (13‐DHAHLA) with Anti‐Inflammatory Properties in Mice

“…detected three positional isomers of LAHLA in oat oil containing equal amounts of 13( R )‐ and 13( S )‐HLA. [ 6 ] It has been shown that non‐enzymatic oxidation of oat lipids was needed for oat lipoxygenases to proceed with lipid oxidation [ 41 ] and this could result in equal amounts of the ( R ) and ( S ) forms of 13‐LAHLA in oat. Given the potential stereochemistry, double bond position and configuration of the FAHFA acyl chains, future studies of biological effects will be needed to explore the structure–activity relationships and to design FAHFA structural analogs for medicine.…”