Combination of epigallocatechin gallate with l-cysteine in inhibiting Maillard browning of concentrated orange juice during storage

Abstract

Orange juice is popular with consumers because of its unique taste, flavor as well as nutritional value which accounts for a large proportion of the global juice market. Concentrated orange juice (COJ), undergoes browning during storage seriously affecting its quality and commercial. This study was the first to evaluate the effects of epigallocatechin gallate (EGCG) and l-cysteine (L-cys) on Maillard browning of COJ during storage. The results show that EGCG and L-cys reduce significantly the production of 5-hydroxymethylfurfural (5-HMF), the characteristic product of Maillard reaction (MR), and the combined use of EGCG and L-cys was even more effective. Furthermore, the color of the treated COJ displayed negligible change after storage, with higher L* and b* values and marginally lower a* values. The flavor, taste, main volatile substances as well as rheological properties of the treated COJ were also determined; none of these properties were affected adversely during storage. This treatment method ensures that the key sensory quality and material properties of COJ are preserved by the proposed treatment while inhibiting Maillard browning during storage.