. Milk fermentation
To prepare double pasteurised milk, fresh pasteurised full-cream milk purchased at a local supermarket was heat treated at 80 °C for
15 min. Kefir was manufactured by adding 9.0 g of the activated kefir grains into 500 ml of double-pasteurised milk in sterile screw-capped
bottles followed by incubation at 25 °C for 72 h.