Presentation on theme: "Lactose intolerance and the production of lactose-free milk Ein Beitrag im Rahmen des Projekts Durchgeführt und präsentiert von den Chemisch-Technischen."— Presentation transcript:
Lactose intolerance and the production of lactose-free milk Ein Beitrag im Rahmen des Projekts Durchgeführt und präsentiert von den Chemisch-Technischen Assistenten an der
20 October 2009 Klasse 2BKC2 Index 1.Incidence of lactose intolerance 2.Cause of lactose intolerance 3.Symptoms of lactose intolerance 4.Help for lactose intolerant persons 5.Lactose-free milk and milk products 6.Large-scale production of lactose-free milk 7.Lab-scale production of lactose-free milk 8.References
20 October 2009 Klasse 2BKC2 Lactose intolerance Many people have problems with the digestion of milk and milk products: Drinking a glass of milk will have unpleasant side effects for them. Germans10-20% Austrians20-25% Slovenes24% Spaniards30% North Italians52% Sicilians71% Worldwide more than 80% of adults cannot digest the milk sugar lactose: This condition is called lactose intolerance.
20 October 2009 Klasse 2BKC2 Occurence of lactose-intolerance
20 October 2009 Klasse 2BKC2 Yet, lactose-intolerant adults began their lives drinking milk from a bottle or breast and digesting it completely. Babies produce the enzyme lactase in their small intestine. This enzyme breaks down lactose. Therefore: Babies are lactose tolerant
20 October 2009 Klasse 2BKC2 Lactase Lactase acts as a pair of molecular scissors: It snips the disaccaride lactose in two simple sugars, galactose and glucose: Lactose tolerant individuals produce lactase for life. For them, a bar of milk chocolate is a pleasant experience.
20 October 2009 Klasse 2BKC2 80 % of adults worldwide do not produce lactase For them, the pleasure of eating chocolate, a scoop of dairy ice cream or some cheese has unpleasant consequences.
20 October 2009 Klasse 2BKC2 Symptoms of lactose intolerance: bloated feeling, stomach cramps diarrhoea flatulence nausea, vomitting
20 October 2009 Klasse 2BKC2 Help for people with lactose intolerance Undigested lactose in the small and large intestine is the common cause for the nasty discomforts suffered by lactose intolerant persons. lactase–tablets to be taken with lactose containing meals lactose-free milk products produced by breaking down lactose using lactase sour milk products lactose converted to lactic acid using microbes
20 October 2009 Klasse 2BKC2 Market for lactose-free products on the rise Increasing demand from developing countries Increasing range of healthy and tasty lactose-free milk products yoghourts ice cream cream in coffee pudding cheese Most of these are produced by OMIRA
20 October 2009 Klasse 2BKC2 Large-scale industrial production of lactose-free milk Lactose is split into glucose and galactose by adding the enzyme lactase to milk Production of lactase enzyme is expensive: It is manufactured by microorganisms and has to be purified from these. Key to economic production of lactose-free milk: Immobilization of lactase Lactase is included within a matrix; milk is continuously pumped through it No residual lactase in milk Enzyme can be re-used frequently
20 October 2009 Klasse 2BKC2 Lab-scale in vitro production of lactose- free milk: Immobilization of Lactase by Na-alginate Enzyme solution is prepared and mixed with the Na-alginate solution Mixture is dropped into a solution of calcium chloride to harden the alginate beads The lactase-beads are collected. They can be re-used for about a month.
20 October 2009 Klasse 2BKC2 The lactase-beads are added to conventional cows milk, whey, or lactose-solution Cleavage of lactose into galactose and glucose is detected by glucose test strips MinusL +
20 October 2009 Klasse 2BKC2 Results Lactose cleavage by lactase as a function of time judged by Glucose test sticks Glucose content (%) Time elapsed after lactase addition 0 min 5 min 10 min 20 min 40 min 80 min 24 h Milk (4.8% lactose)00, ,05,0 Whey % Lactose-solution % Saccharose-solution
20 October 2009 Klasse 2BKC2 Results Cleavage of lactose by lactase was also confirmed by HPLC: LactoseLactose + Lactase