Van Wayenbergh Eline, Blockx Jonas, Langenaeken Niels A, Foubert Imogen, Courtin Christophe M
Laboratory of Food Chemistry and Biochemistry & Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M2S), KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
Research Unit of Food and Lipids & Leuven Food Science and Nutrition Research Centre (LFoRCe), Department of Microbial and Molecular Systems (M2S), KU Leuven KULAK, Etienne Sabbelaan 53, B-8500 Kortrijk, Belgium.
Foods. 2023 Dec 25;13(1):80. doi: 10.3390/foods13010080.
Wheat bran can be used as a cost-effective food ingredient to stabilise vitamin A. However, wheat bran endogenous enzymes have been shown to reduce vitamin A stability. In this study, we elucidated the mechanism for this negative effect in an accelerated storage experiment with model systems consisting of native or toasted wheat bran, soy oil and retinyl palmitate (RP). Both native and toasted wheat bran substantially stabilised RP. While RP was entirely degraded after ten days of storage in the absence of wheat bran, the RP retention after ten days was 22 ± 2% and 75 ± 5% in the presence of native and toasted bran, respectively. The significantly stronger stabilising effect of toasted bran was attributed to the absence of bran endogenous enzymes. In contrast to toasted bran systems, noticeable free fatty acid production was observed for native bran systems. However, this did not result in a pronounced lipid oxidation. Next to lipid hydrolysis, wheat bran lipase was shown to hydrolyse retinyl esters to the less stable retinol and fatty acids. This reaction could explain the major part, about 66 ± 5%, of the difference in RP stabilisation between native and toasted wheat bran.
麦麸可用作一种经济高效的食品成分来稳定维生素A。然而，已表明麦麸内源性酶会降低维生素A的稳定性。在本研究中，我们在由天然或烘焙麦麸、大豆油和棕榈酸视黄酯（RP）组成的模型体系加速储存实验中阐明了这种负面影响的机制。天然麦麸和烘焙麦麸均能显著稳定RP。在没有麦麸的情况下储存十天后RP完全降解，而在有天然麦麸和烘焙麦麸存在的情况下，十天后的RP保留率分别为22±2%和75±5%。烘焙麦麸显著更强的稳定作用归因于其不存在麦麸内源性酶。与烘焙麦麸体系不同，在天然麦麸体系中观察到明显的游离脂肪酸生成。然而，这并未导致明显的脂质氧化。除了脂质水解外，已表明麦麸脂肪酶会将视黄酯水解为稳定性较低的视黄醇和脂肪酸。该反应可以解释天然麦麸和烘焙麦麸之间RP稳定性差异的主要部分，约为66±5%。
