Low-lactose yoghurt production using β-galactosidase: An integrated study for the enzyme and its application

Abstract

Lactose is broken down into easily digested simple sugars, glucose and galactose, by β-galactosidase. A low-cost β-galactosidase was successfully applied to introduce low-lactose yoghurt that is safe, affordable, and local for patients who are lactose intolerant (LI). These dairy products (DP) are already on the market, but they are fairly pricey and taste very different from regular products due to by-products of chemical reactions. LI patients require special DP to avoid the health risks associated with regular products. A concentration of 0.3% Lactobacillus paracasei β-galactosidase produced yoghurt with 2.5 g lactose 100 g−1 yoghurt, suitable for lactose-intolerant patients, allowing them to consume more DP without compromising the product's consistency, colour, or flavour. The enzyme's physicochemical, kinetic, and thermodynamic properties were thoroughly investigated. The chemical, rheological, and sensory properties of the low-lactose yoghurt produced were also assessed. Fresh yoghurt received a sensory evaluation score of 92.67, unchanged after 9 days.