McDougall Gordon J, Dobson Patricia, Smith Pauline, Blake Alison, Stewart Derek
Quality, Health and Nutrition Program, Genes to Products Theme, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, United Kingdom.
J Agric Food Chem. 2005 Jul 27;53(15):5896-904. doi: 10.1021/jf050131p.
The bioavailability of anthocyanins from raspberry extracts was assessed using an in vitro digestion procedure that mimics the physiochemical and biochemical changes that occur in the upper gastrointestinal tract (GIT). Effectively all of the total phenol content of the raspberry extract survived gastric digestion and partitioned between the IN sample, which represents the serum available material, and the OUT sample, which represents the material that remains in the GIT and passes through to the colon. All of the anthocyanins also survived gastric digestion, but only approximately 5% entered the IN sample and approximately 70% of total anthocyanins were recovered in the IN and OUT samples. Codigestion of the raspberry extract with commonly combined foodstuffs such as bread, breakfast cereal, ice cream, and cooked minced beef gave a different pattern. The total phenol content of the IN samples was slightly reduced by codigestion with ice cream or breakfast cereal but unaffected by codigestion with bread or minced beef. In most cases, the phenol contents of the postgastric and OUT samples were reduced as compared with the expected values. However, the anthocyanin content of the IN samples was unaffected or increased by coincubation with the foodstuffs. This suggests that polyphenols transiently bind to food matrices during digestion, which protects the more labile anthocyanins from degradation, and they are free to diffuse into the IN sample. The anthocyanin composition of the bioavailability samples was monitored by liquid chromatography-mass spectrometry. All eight anthocyanins previously identified in raspberry were detected in the extract and the postgastric samples at similar yields. All eight anthocyanins could be discerned in the IN and OUT samples, but some such as cyanidin-3-O-glucoside were greatly reduced and others such as pelargonidin-3-O-glucoside were apparently increased in abundance. These differences in stability and their importance for the bioavailability of anthocyanins are discussed.
使用一种体外消化程序评估了树莓提取物中花色苷的生物利用度，该程序模拟了上消化道（GIT）中发生的物理化学和生化变化。实际上，树莓提取物中的所有总酚含量在胃消化过程中均得以保留，并在代表血清可利用物质的IN样品和代表留在胃肠道并进入结肠的物质的OUT样品之间进行分配。所有花色苷也在胃消化过程中幸存下来，但只有约5%进入IN样品，并且约70%的总花色苷在IN和OUT样品中被回收。树莓提取物与面包、早餐谷物、冰淇淋和熟牛肉末等常见混合食品共同消化呈现出不同的模式。与冰淇淋或早餐谷物共同消化时，IN样品中的总酚含量略有降低，但与面包或牛肉末共同消化时不受影响。在大多数情况下，与预期值相比，胃后和OUT样品中的酚含量降低。然而，与食品共同孵育时，IN样品中的花色苷含量未受影响或有所增加。这表明多酚在消化过程中会短暂地与食物基质结合，从而保护更不稳定的花色苷不被降解，并且它们可以自由扩散到IN样品中。通过液相色谱-质谱法监测生物利用度样品中的花色苷组成。提取物和胃后样品中均以相似的产率检测到了先前在树莓中鉴定出的所有八种花色苷。在IN和OUT样品中都可以辨别出所有八种花色苷，但一些如矢车菊素-3-O-葡萄糖苷大幅减少，而另一些如天竺葵素-3-O-葡萄糖苷的丰度明显增加。讨论了这些稳定性差异及其对花色苷生物利用度的重要性。
