Abstract :
Set-type low-fat yogurt from goat’s milk, prepared by using yogurt starter bacteria and
potential probiotic lactobacilli, was studied for physicochemical, microbiological and sensory
characteristics. Selected isolates of Streptococcus thermophilus (2 strains), Lactobacillus
delbrueckii subsp. bulgaricus (2) from goat’s milk yogurt and Lactobacillus paracasei subsp.
paracasei (1) and Lactobacillus acidophilus (1) from new born infant faeces were tested for
their ability to grow and metabolize in goat milk and for their in vitro resistance to the
specific conditions of the human gastrointestinal tract. Results revealed that L. paracasei
subsp. paracasei and L. acidophilus strains were distinguished for their potential probiotic
properties (resistance to low pH, tolerance to 0.15% bile salts, cholesterol removal from the
medium, resistance to 100 ppm lysozyme), as well as for high diacetyl production. The synergistic
growth of selected strains was shown by growing six single-strain cultures and one
multi-strain culture in goat milk, so the later one was used to produce a set-type yogurt from
goat milk. The product was characterized by high numbers (∼108 cfu/g) of potential probiotic
lactobacilli; it contained carbonyl compounds and had a satisfactory consistency with
good organoleptic characteristics. This study depicted the ability to successfully produce
set-type yogurt from caprine milk by implementing beneficial lactobacilli strains.
