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This study evaluated transepithelial transport mechanisms of Ile‐Gln‐Pro (IQP) and Val‐Glu‐Pro (VEP), two ACE‐inhibitory peptides derived from Spirulina platensis, using human intestinal Caco‐2 cell monolayers. IQP and VEP were absorbed intact through Caco‐2 cell monolayers with Papp values of 7.48 ± 0.58 × 10−6 and 5.05 ± 0.74 × 10−6 cm/s, respectively. The transport of IQP and VEP were affected neither by Gly‐Pro nor by wortmannin, indicating that they were not PepT1‐mediated and did not involve endocytosis. However, transport of IQP and VEP were increased significantly by sodium deoxycholate, suggesting that the major transport mechanism was paracellular. In addition, the increased transport of VEP and IQP were followed with the addition of sodium azide, suggesting influence of energy to the process. The transport of VEP was also increased by verapamil, indicating an apical‐to‐basolateral flux mediated by P‐gp. Practical Application: Bioactive peptides derived from food proteins have been considered as potentially ideal products to reduce hypertension because of their safety and positive impacts on health. IQP and VEP are the 2 ACE inhibitory peptides derived from Spirulina platensis, a kind of edible cyanobacteria with rich nutrition and multiple physiological functions, and were demonstrated to inhibit ACE and lower blood pressure in spontaneously hypertensive rats. However, it is prerequisite that such bioactive peptides must be absorbed intact across the intestinal epithelium, so as to exert antihypertensive effects in vivo. This study evaluated transepithelial transport mechanisms of IQP and VEP. It contributes to the study of Spirulina in lowering blood pressure and supports the development of bioactive peptide products. [ABSTRACT FROM AUTHOR]

Spirulina platensis is a high-nutrient blue-green alga with a long history as a food supplement. In this study, the mixed fermentation of Spirulina with Lactobacillus plantarum and Bacillus subtilis was investigated using random-centroid optimization to improve deodorization of off-flavor and hydrolysis of protein. Fermented Spirulina with the maximum total viable counts of both organisms achieved best sensory characteristics and degree of proteolysis among those with different maximum biomass. The mixed fermentation noticeably reduced the volatile compounds of Spirulina , and yielded the highest relative contents (>85%) of acetoin and other odorants collectively producing a creamy aroma. Approximately one-third of the Spirulina proteins were hydrolyzed, yielding over 16% polypeptides and increasing the ratio of essential amino acids to total free amino acids to 1.5-fold compared with unfermented Spirulina . Fermentation with B. subtilis and L. plantarum effectively improved the odor and protein availability of Spirulina . [ABSTRACT FROM AUTHOR]