2.4. Technological aspects
Several factors must be considered when selecting a probiotic
strain for food applications. Among other requirements,
they should not affect the sensory characteristics
of the food in any perceptible way; remain stable throughout
processing and storage of the product; and be resistant
to the gastrointestinal environment (Mattila-Sandholm
et al., 2002).
To ensure the therapeutic activity and effectiveness that
provide benefits for the human body, several international
organizations issued standards establishing minimum viable
counts for probiotic microorganisms to assure the biological
effect in the intestinal environment. Most of these
organizations introduced standards requiring minimum
levels of 107 CFU/mL for L. acidophilus and 106 of Bifidobacteria
in fermented milk products at the time of sale (Talwalkar
& Kallasapathy, 2003). In Japan, the Fermented
Milk and Lactic Beverages Association has specified that
there be at least 107 CFU/mL of viable Bifidobacteria cells
in fermented milk drinks. To achieve the desired effects in
probiotic yogurts, it is recommended that the minimum
counts of viable probiotic bacteria be at least 108 CFU/
mL (Lourens-Hattingh & Viljoen, 2001).
Such high numbers have been suggested to compensate
for the possible loss in the numbers of probiotic organisms
during passage through the stomach and the intestine. It is
therefore recommended that the minimum counts of probiotic
bacteria be 106 CFU/g of the product at the expiry
date (Kurman & Rasic, 1991).