Abstract
Synthetic model systems of concentrated lemon juice (50%) were prepared with different contents of some compounds (Ascorbic acid ,Reducing Sugar , Amino acids) that may play an important role in brown pigments ( Melanoidins )formation. Samples were stored at 25 and 35ْ c for 12 weeks .Results showed that the main brown pigments formation pathway in this highly acidic synthetic model system (pH >2.5) was ascorbic acid degradation rather than reducing sugar acid decomposition and strecker decomposition of amino acid.
