Abstract: In this study, the antihypertensive effect of microcapsules containing a mixture of goji berry, hawthorn and cassia seed at a mass ratio of 4:1:1 and angiotensin converting enzyme (ACE) inhibitory peptide in spontaneously hypertensive rats (SHR) was assessed. The ACE inhibition rate of the microcapsules containing the mixture and ACE inhibitory peptide at a mass ratio of 1:2 was 78.19%, which was significantly higher than those of the mixture of medicinal and culinary plant materials (69.46%) and ACE inhibitory peptide (71.48%) alone (P < 0.05). Under optimized encapsulation conditions (solid content of 10%, inlet air temperature of 160 ℃, core-to-wall ratio of 1:15, and a 1:4 mixture of modified starch and maltodextrin as wall material), an encapsulation efficiency of 82.76% was obtained. After intestinal digestion for 240 min, the release rate of the as-prepared microcapsules was 81.40%, and the bitter taste was significantly reduced (P < 0.05). Animal experiments showed that the microcapsules significantly reduced blood pressure in SHR, significantly increased the plasma contents of ACE2 and angiotensin 1-7 (Ang(1-7)), and reduced plasma ACE content and the contents of angiotensin II (AngII) in the plasma, heart, kidney and thoracic aorta (P < 0.05). The effect was more pronounced than those of the mixture of medicinal and culinary plant materials and ACE inhibitory peptide, confirming the synergism between them. The composite microcapsules can not only reduce blood pressure by regulating the renin-angiotensin system but also significantly reduce the degree of cardiac and thoracic aorta fibrosis in SHR, thereby improving organ damage caused by hypertension.

Key words: medicine food homology; angiotensin converting enzyme inhibitory activity; microcapsules; antihypertensive