Lipid-modifying enzymes in oat and faba bean
Lipid-modifying enzymes in oat and faba bean
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DOI：
10.1016/j.foodres.2017.07.005
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发表时间：
2017-10-01
影响因子：
8.1
通讯作者：
Lampi, Anna-Maija
中科院分区：
文献类型：
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作者：
Yang, Zhen;Piironen, Vieno;Lampi, Anna-Maija
目的是研究脂肪酶，脂肪氧合酶（LOX）和过氧合酶（PDX）的活动在燕麦和蚕豆样品，能够评估其潜在的形成脂质衍生的异味。脂肪酶和脂氧合酶的活性通过光谱法测定，PDX活性通过环氧化物的形成。建立了超高效液相色谱法研究脂肪酸环氧化物的形成。用气相色谱法测定酯的环氧化物。质谱用于验证环氧化物的身份。燕麦和蚕豆都具有较高的脂肪酶活性。在蚕豆中，LOX催化氢过氧化物的形成，其分解产物是异味的可能原因。由于燕麦具有低LOX活性，因此需要自氧化来启动脂质氧化。燕麦具有高PDX活性，其能够将氢过氧化物转化为环氧和羟基脂肪酸，这可能显著地导致异味。蚕豆中的PDX活性较低。因此，在蚕豆挥发性脂质氧化产物可以迅速形成LOX，而在燕麦反应较慢，由于需要自氧化之前，进一步的反应。
The aim was to study lipase, lipoxygenase (LOX) and peroxygenase (PDX) 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 PDX 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 PDX activity, which is able to convert hydroperoxides to epoxy and hydroxy fatty acids that could contribute significantly to off-flavours. PDX 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.