Article

Batch-fermentations and pH-controlled experiments were used to compare the angiotensin-converting enzyme inhibitory activity (ACEIA) of fermented milk products. High values of ACEIA were determined for milks after prolonged batch fermentations (24h, 37°C) of single cultures of three Lactobacillus helveticus and two L. delbrueckii ssp. bulgaricus strains. Fermentations performed at constant pH did not result in higher ACEIA in the milk medium. L. helveticus strain Hv28 or L. bulgaricus strain 4/149 alone or in combination with S. thermophilus were used to prepare prototype fermented milk products and their ACEIA was evaluated. Fermented products obtained for 24h of incubation possessed the highest ACEIA, but had strong taste and required additives. Yoghurt-like products and products obtained with the slow acidifier L. bulgaricus strain 4/149 had moderate ACEIA, but had much more acceptable sensory qualities.