2.4. Yoghurt manufacture
To produce the stirred probiotic yoghurt, UHT milk was standardized
(14% solids) by addition of skimmed milk powder, heattreated
(95 C/5 min), cooled (45 C), added of 1.25% culture of
S. thermophilus, 1.25% culture of L. bulgaricus, and 1% culture of
L. acidophilus (prepared as described in Section 2.2.). At the end of fermentation (pH 4.8 ± 0.05), the yoghurt was cooled (10 C). After
24 h of cold storage, the product was stirred and subjected to
microbiological analysis.