Fructose Maillard reaction

Chemically, fructose is very active and it readily takes part in maillard reactions, which may cause browning in some products. It is available in crystalline anhydrous form and also in high-concentration syrups. 

Milk-crumbs and soya-crumbs are new aroma sources produced by the Maillard reaction and intended to be used in the food industry. During the production of the crumbs thermal reactions take place in the material (e.g. milk) and the added glucose and amino acid constituents. Fructose-lysine and... 

It is well known that the Maillard reaction in foods is initiated by the formation of colorless and tasteless intermediates, which preferentially are formed in low-moisture systems ( ,5.). In this way by reaction of glucose with amino acids fructose-amino acids are formed via Amadori rearrangement of the primary glucosyl-ami-no acids (1 ). Fructose-amino acids e.g. have been isolated from freeze-dried apricots and peaches ( 6,7,8j. Amadori compounds arising from aldoses and amino acids are formed during drying of foods of plant origin and can be easily detected by amino acid analysis (j>). 

In former experiments (5) we have shown that chemical analysis for Amadori compounds (mainly consisting of fructose-glutamic acid) and isovaleralde-hyde, formed by Strecker degradation of the amino acids leucine and isoleucine, can be used for an early detection of undesirable quality changes caused by the Maillard reaction. In order to demonstrate the usefulness of these compounds as indicator substances for quality improvement of dried products, we performed drying experiments with carrots as an example of plant products. 

The most efficient method for the clean hydrolysis of sucrose is by the use of invertase, leading to an equimolar mixture of glucose and fructose (invert sugar). The presence of salts increases the rate of thermal degradation of sucrose.337 The reaction is also possible in the presence of such heterogeneous acidic catalysts as zeolites.338 The hydrolysis of the glycosidic bond is the first step of a number of subsequent reactions that can occur on the glucose and fructose residues, such as dehydrations, combinations with amino acids (Maillard reaction), and many other chemicals or fermentation processes.339... 

The purpose of this work was to investigate the occurrence and heat-induced origin of cyclic dipeptides (DKPs) in cocoa and separately, to study the mechanism of DKP formation in simplified reaction systems. Also, the formation of volatiles vas measured in a series of model Maillard reactions of peptides, amino acid mixtures and fructose. 

E.-H. Ajandouz, L. S. Tchiakpe, F. Dalle Ore, A. Benajiba, and A. Puigserver, Effects of pH on caramelization and Maillard reaction kinetics in fructose-lysine model systems, J. Food Sci., 2001, 66, 926-931. 

Jing, H. and Kitts, D.D. 2000. Comparison of the antioxidative and cytotoxic properties of glucose-lysine and fructose-lysine Maillard reaction. Food Res. Int. 33, 509-516. 

During baking there is an evaporation of water from the loaf, this is particularly marked near the surface of the loaf, and this evaporation plus the occurrence of the Maillard reaction cause a characteristic dark brown crust to be formed on the exterior of the loaf. The Maillard reaction is a complex set of chemical reactions in which the amino acids in proteins react with reducing sugars such as glucose and fructose, and which are very important to our perception of flavour in baked bread. 

Furaneol is formed when the sugar rhamnose is heated in the presence of a substance containing an amino group through a Maillard reaction (Fig. 3.62). HMF results from heating of fructose (Fig. 3.63). Both furanones occur in various foods. For example, Furaneol has been identified in pineapple, strawberries and popcorn both Furaneol and HMF have been found in meat broth [21 [. Both furanones are applied as flavour modifiers in foods where maltol and ethyl maltol are used [1[. 

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