Department of Food and Drug, University of Parma, 43124 Parma PR, Italy.
Nutrients. 2019 Apr 30;11(5):985. doi: 10.3390/nu11050985.
In this study we investigated the oligopeptide pattern in fermented cocoa beans and derived products after simulated gastrointestinal digestion. Peptides in digested cocoa samples were identified based on the mass fragmentation and on the software analysis of vicilin and 21 KDa cocoa seed protein sequences, the most abundant cocoa proteins. Quantification was carried out by liquid chromatography/electrospray ionisation mass spectrometry (LC/ESI-MS) using an internal standard. Sixty five peptides were identified in the digested samples, including three pyroglutamyl derivatives. The in vitro angiotensin-converting enzyme (ACE)-inhibitory activity of cocoa digests were tested, demonstrating a high inhibition activity, especially for digestates of cocoa beans. The peptides identified were screened for their potential ACE inhibitory activity through an in silico approach, and about 20 di-, three- and tetra-peptides actually present in our samples were predicted as active. Two of the potentially active peptides were chemically synthesized and then assessed for their inhibitory activity by using the ACE in vitro assay. These peptides demonstrated an ACE inhibitory activity, however, that was too weak to explain alone the high activity of cocoa digestates, suggesting a synergic effect of all cocoa peptides. As a whole, results showed that an average chocolate portion (30 g) ensures an amount of peptides after digestion that, assuming complete absorption, could reach almost a complete inhibition of ACE.
在这项研究中，我们研究了模拟胃肠道消化后发酵可可豆和衍生产品中的寡肽模式。基于马麦球蛋白和 21 kDa 可可种子蛋白序列（最丰富的可可蛋白）的质量断裂和软件分析，鉴定了消化可可样品中的肽。使用内部标准通过液相色谱/电喷雾电离质谱（LC/ESI-MS）进行定量。在消化样品中鉴定出 65 种肽，包括三种焦谷氨酸衍生物。测试了可可消化物的体外血管紧张素转换酶（ACE）抑制活性，结果表明其具有很高的抑制活性，尤其是可可豆消化物的抑制活性。通过计算机筛选方法筛选了这些肽的潜在 ACE 抑制活性，约 20 种二肽、三肽和四肽实际上存在于我们的样品中，被预测为具有活性。其中两种潜在的活性肽被化学合成，然后通过 ACE 体外测定法评估其抑制活性。这些肽表现出 ACE 抑制活性，但弱到不足以单独解释可可消化物的高活性，表明所有可可肽具有协同作用。总的来说，结果表明，食用一份（30 克）巧克力可确保在消化后获得一定量的肽，假设完全吸收，可达到几乎完全抑制 ACE 的效果。
