Characterisation of in vitro gastrointestinal digests from low fat caprine kefir enriched with inulin

• Published in: International dairy journal 2017-12, Vol.75, p.68-74
• Main Authors: Simsek, Sebnem, Sánchez-Rivera, Laura, El, Sedef Nehir, Karakaya, Sibel, Recio, Isidra
• Format: Article
• Language: English
• ISSN: 0958-6946; 1879-0143; 1879-0143
• DOI: 10.1016/j.idairyj.2017.07.004

In vitro gastrointestinal digests from low fat caprines' milk kefir were characterised. The impact of the addition of different types of inulin (native, short-chain and long-chain) as a fat replacer on the subsequent release of peptides during digestion was also studied. A total of 52 peptides were identified, mainly from β-casein, following digestion. The gastrointestinal digests possessed angiotensin-converting enzyme (ACE)-inhibitory activity with IC50 values ranging from 190.71 ± 2.91 to 364.68 ± 31.27 μg protein mL−1. Among the identified peptides, four of them have been previously described as ACE-inhibitors (LHLPLP, HLPLP, DKIHP, MAIPPK), and the presence of these sequences can explain the moderate ACE-inhibitory activity found in the samples. Rheological analysis revealed that all manufactured kefirs exhibited shear-thinning behaviour. No significant effect of viscosity on protein degradation during simulated gastrointestinal digestion was found under the working conditions.