Ein Beitrag im Rahmen des Projekts Lactose intolerance

Ein Beitrag im Rahmen des Projekts Lactose intolerance and the production of lactose-free milk Durchgeführt und präsentiert von den Chemisch-Technischen Assistenten an der

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 2 BKC 2

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. Germans 10 -20% Austrians 20 -25% Slovenes 24% Spaniards 30% North Italians 52% Sicilians 71% Worldwide more than 80% of adults cannot digest the milk sugar lactose: This condition is called lactose intolerance. 20 October 2009 Klasse 2 BKC 2

Occurence of lactose-intolerance 20 October 2009 Klasse 2 BKC 2

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 2 BKC 2

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 2 BKC 2

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 2 BKC 2

Symptoms of lactose intolerance: bloated feeling, stomach cramps diarrhoea nausea, vomitting flatulence 20 October 2009 Klasse 2 BKC 2

„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 2 BKC 2

Market for lactose-free products on the rise Increasing demand from developing countries Increasing range of healthy and tasty lactose-free milk products ice cream yoghourts cheese pudding cream in coffee Most of these are produced by OMIRA 20 October 2009 Klasse 2 BKC 2

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 2 BKC 2

Lab-scale in vitro production of lactosefree 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 2 BKC 2

• The lactase-beads are added to conventional cow‘s milk, whey, or lactose-solution + Minus. L • Cleavage of lactose into galactose and glucose is detected by glucose test strips 20 October 2009 Klasse 2 BKC 2

Results Lactose cleavage by lactase as a function of time judged by Glucose test sticks Glucose content (%) 0 min 5 min 10 min 20 min 40 min 80 min 24 h Milk (4. 8% lactose) 0 0, 05 0. 2 0. 4 0. 7 1, 0 5, 0 Whey 0 0. 1 0. 5 0. 7 1. 0 2. 0 4. 8% Lactose-solution 0 0. 1 0. 2 0. 5 0. 6 1. 5 5. 0 4. 8% Saccharose-solution 0 0 0 0 Time elapsed after lactase addition 20 October 2009 Klasse 2 BKC 2

Results Cleavage of lactose by lactase was also confirmed by HPLC: Lactose + Lactase 20 October 2009 Klasse 2 BKC 2

References: http: //www. familiesonline. co. uk/articleview/1399/1/22/ http: //www. spiegel. de/img/0, 1020, 122495, 00. jpg http: //valiblog. files. wordpress. com/2008/08/babyflasche. jpg 46 http: //en. wikipedia. org/wiki/File: Lac. Intol-World 2. png http: //www. foodreactions. org/colic/ http: //www. meuterei 2008. de/fileadmin/templates/_gfx/sponsor_minusl. jpg 20 October 2009 Klasse 2 BKC 2