Di-D-fructose dianhydride-enriched products by acid ion-exchange resin-promoted caramelization of D-fructose: chemical analyses.
Caramelization commonly occurs when sugars, or products containing a high proportion of sugars, are heated either dry or in concentrated aqueous solutions, alone or in the presence of certain additives. Upon thermal treatment of sugars, dehydration and self-condensation reactions occur, giving rise to volatiles (principally 2-hydroxymethylfurfural, HMF), pigments (melanoidines) and oligosaccharidic material, among which di-D-fructose dianhydrides (DFAs) and glycosylated DFA derivatives of different degree of polymerization (DP) have been identified. This study reports a methodology to produce caramel-like products with a high content of DFAs and oligosaccharides thereof from commercial D-fructose based on the use of acid ion-exchange resins as caramelization promotors. The rate of formation of these compounds as a function of D-fructose concentration, catalyst proportion, temperature, catalyst nature and particle size has been investigated. The use of sulfonic acid resins allows conducting caramelization at remarkable low temperatures (70-90 degrees C) to reach conversions into DFA derivatives up to 70-80% in 1-2 h, with relative proportions of HMF < 2%.The relative abundance of individual DFA structures can be modulated by acting on the catalyst nature and reaction conditions, which offers a unique opportunity for nutritional studies of DFA-enriched products with well-defined compositions.
Suárez-Pereira
Elena
E
Departamento de Química Orgánica, Facultad de Química, Universidad de Sevilla, Apartado 1203, E-41071 Sevilla, Spain.
Rubio
Enrique M
EM
Pilard
Serge
S
Ortiz Mellet
Carmen
C
García Fernández
José M
JM
D002182:Candy; D002241:Carbohydrates / Q000737:chemistry*; D004187:Disaccharides / Q000737:chemistry*; D005632:Fructose / Q000737:chemistry*; D007475:Ion Exchange Resins / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry
D002241:Carbohydrates; D004187:Disaccharides; D007475:Ion Exchange Resins; D013451:Sulfonic Acids; C569050:caramel coloring; D005632:Fructose