Mat Damien J L, Cattenoz Thomas, Souchon Isabelle, Michon Camille, Le Feunteun Steven
UMR GMPA, AgroParisTech, INRA, Université Paris-Saclay, 78850 Thiverval-Grignon, France; UMR Ingénierie Procédés Aliments, AgroParisTech, INRA, Université Paris-Saclay, 91300 Massy, France.
UMR GMPA, AgroParisTech, INRA, Université Paris-Saclay, 78850 Thiverval-Grignon, France.
Food Chem. 2018 Jan 15;239:268-275. doi: 10.1016/j.foodchem.2017.06.115. Epub 2017 Jun 21.
This study intends to demonstrate that acid titration at low pH is very well adapted to the monitoring of pepsin activity. After a description of the underlying principles, this approach was used during in vitro gastric digestions of a model of complex food containing 15wt% of whey proteins, according to both static (2h at pH = 3, Infogest protocol) and dynamic pH conditions (from pH 6.3 down to 2 in 1h). Pepsin activity was quantitatively assessed in all experiments through the calculation of degrees of hydrolysis (DH). Final values of 3.7 and 3.0% were obtained in static and dynamic pH conditions, respectively, and validated using an independent method. Results also show that about 92% of the peptides were detected at pH = 3, and 100% for pH≤2.5. Overall, the proposed approach proved to be very worthy to study protein hydrolysis during in vitro gastric digestions.
本研究旨在证明低pH值下的酸滴定非常适合监测胃蛋白酶活性。在描述了基本原理之后，该方法被用于对含有15wt%乳清蛋白的复合食物模型进行体外胃消化实验，实验分别采用了静态（pH = 3，2小时，Infogest方案）和动态pH条件（1小时内从pH 6.3降至2）。在所有实验中，通过计算水解度（DH）对胃蛋白酶活性进行了定量评估。在静态和动态pH条件下分别获得了3.7%和3.0%的最终值，并使用独立方法进行了验证。结果还表明，在pH = 3时检测到约92%的肽，而在pH≤2.5时检测到100%的肽。总体而言，所提出的方法被证明对于研究体外胃消化过程中的蛋白质水解非常有价值。
