What You Need to Know
During fermentation, lactic acid bacteria metabolize lactose into lactic acid, lowering the pH to 4.5–5.5 and inhibiting spoilage microbes. The added prebiotic fibers (e.g., inulin, fructooligosaccharides) serve as selective substrates for the probiotics, enhancing their growth and viability. The metabolic activity also generates short‑chain fatty acids and volatile flavor compounds that contribute to the product’s sensory profile.
The Science
Primary Reaction
Fermentation of lactose by lactic acid bacteria producing lactic acid and short‑chain fatty acids