3.6.5 Explain the use of lactase in the production of lactose-free milk скачать в хорошем качестве

3.6.5 Explain the use of lactase in the production of lactose-free milk

Lactose is a disaccharide found in milk which is made up of glucose and galactose, both monosaccharides. Lactase is the enzyme that breaks up lactose into glucose and galactose. Most humans have the ability to break down lactose in milk because they produce lactase in their digestive tract, however is is possible for them to loose this ability over time. If a person does not produce the lactase to breakdown lactose, they are referred to as lactose intolerant. Cats are often lactose intolerant because their production of lactase decreases dramatically after weaning. We can produce lactose-free milk by treating milk containing lactose with the enzyme lactase. This can be done in the lab using the following steps: 1) A syringe is used to add a mixture of sodium alginate and lactase to a solution of calcium chloride drop by drop to form beads of immobilized lactase 2) The immobilized lactase beads are placed inside a syringe which has tubing attached to it (closed by a clamp) and a gauze inside it (to prevent beads from becoming stuck). 3) The milk containing lactose is added and allowed to sit in contact with the lactase 4) Th milk is cycled through and the glucose concentration is tested 5) Steps 3-4 are repeated and the concentration of glucose measured each time Upon repeated cyclings it can be observed that the glucose concentration increases with each cycle. This is because the lactase is gradually breaking down the lactose in the milk into glucose and galactose. The process can be on an industrial scale to treat milk and milk products before they are available for human consumption.