Role of sorbic acid in nonenzymic browning reactions in liquid and solid model food systems

Summary Role of sorbic acid (SA) in browning development in model systems has been studied. In liquid model systems containing water-glycerol-glucose (WGG), water-glycerol-sucrose (WGS), 45% sucrose and 30% sucrose plus 15% glucose, SA degraded when stored at 37°C forming brown pigments. Addition of amino acids (glycine or lysine monohydrochloride) increased the rate of browning development while Cu2+ reduced SA degradation and browning development. In the absence of amino acids and SA, WGG and WGS systems did not brown appreciably. In solid systems with SA adsorbed on microcrystalline cellulose, the maximum rate of browning occurred at 0.73aw, but maximum rate of SA loss was at 1.0aw. In all systems inclusion of amino acids reduced SA degradation but increased browning development. The rate of SA-induced browning was considerably higher than that caused by sugar-amino acid interactions.