Physicochemical properties and anthocyanin content of commercially manufactured elderberry jams from Patagonia (Argentina)

摘要

Commercially manufactured elderberry jams elaborated in Patagonia, Argentina, were analyzed for physico-chemical characteristics. Water activity (aw) ranged between 0.758 and 0.972 and total monomeric anthocyanin (TMA) content varied from 2.4 up to 55 mg Cy-3G/100 g jam. Relationship between a(w) and (degrees)Brix in jams was described using an equation for correlating water activity in non-electrolyte solutions. Elderberry jam samples were stored at 38 C-degrees and samples periodically withdrawn for analysis. TMA degraded following first order reaction kinetics and color parameter a* decreased during storage while parameter h(degrees) increased. Water activity and presence of fructose in jams increased rate of TMA destruction and adversely affected color changes. Studies with sugar solutions containing anthocyanins confirmed TMA degradation is faster in models having reducing sugars than in the presence of sucrose. It is shown that sucrose may undergo hydrolysis during acid catalyzed storage at 38 C-degrees and pH 3.5.