African fermented milk (nunu, amasi)

Description

African fermented milk (nunu, amasi) is produced by lactic acid bacteria at 30–35 °C, generating acidity, proteolysis, and bioactive peptides that confer flavour, preservation, and potential health benefits.

Technical

During fermentation, Lactobacillus and Streptococcus spp. convert lactose into lactic acid, lowering the pH to 4.3–4.6 and inhibiting spoilage organisms. Proteolytic enzymes released by the bacteria cleave casein and whey proteins into peptides and free amino acids, some of which possess ACE‑inhibitory activity. The combined acidification and proteolysis produce a characteristic tangy flavour and a semi‑solid texture with curd formation.

Science

Primary Reaction

Lactose → lactic acid + CO₂ (fermentation) + proteolysis of milk proteins → peptides and free amino acids

Sensory Profile

Origin & History