Non-Enzymatic Browning: Millard Reaction

1. Non-Enzymatic Browning:Millard Reaction • Nonenzymatic browning is found in food processing operations involving dehydration/ condensed milk. • Nonenzymatic browning is purely chemical and occurs by several mechanisms. • TheMaillard Reaction is a chemical reaction between an amino acid and a reducing sugar, usually requiring heat.

2. Non-Enzymatic Browning:Millard Reaction Reducing sugars Amino compounds + Temperature Conc. of the reactants pH Inhibitors or preservatives Amines, amino acid, proteins Glucose, Fructose, lactose, Maltose Melanoidins

3. Non-Enzymatic Browning:Millard Reaction • Browning reactions may be: - desirable to the food crust on baked goods, color of caramel, flavor, color of maple syrup - detrimental to the food darkening of dehydrated fruits , eggs, vegetables, canned or dried milk

4. 60 5 55 10 50 45 15 40 20 35 25 30 30 min. 1 2 3 4 5 6 100ºC 50ْ Brix invert sugar (ml) 4 4 4 4 4 4 Mix Well on a vortex mixer 10% glycine 1 1 1 1 1 1 (ml) Read the Optical Density at 420 nm Buffer 1 1 1 1 1 1 (ml) pH 3pH 4 pH 5pH 6pH 7pH 8

5. 60 5 55 10 50 45 15 40 20 35 25 30 30 min. 7 Mix Well 1ml buffer pH 8 1ml 10% glycine 4ml 50ْ Brix invertsugar 70ºC Read the Optical Density at 420 nm

6. 60 5 55 10 50 45 15 40 20 35 25 30 30 min. 8 Mix Well 0.1g Sodium metabisulphate 1ml buffer pH 8 1ml 10% glycine 4ml 50ْ Brix invertsugar 100ºC Read the Optical Density 420 nm

7. 60 5 55 10 50 45 15 40 20 35 25 30 30 min. 9 Mix Well 1ml buffer pH 8 1ml D.W. 4ml 50ْ Brix invertsugar 100ºC Read the Optical Density 420 nm

8. 60 5 55 10 50 45 15 40 20 35 25 30 30 min. Blank 10 Mix Well 1ml buffer pH 8 1ml D.W. 4ml 50ْ Brix invertsugar 25ºC Read the Optical Density 420 nm

9. Results: Samar A. Damiati