Enhancement of Strawberry Marmalade with Crab Apple (Malus floribunda) Anthocyanins

The usability of crab apple (Malus floribunda) as a natural colorant and anthocyanin source to stabilize the color of strawberry marmalades was investigated. Crab apple juice concentrate was added to strawberry marmalades at a rate of 2% during the production phase. The pH values of the samples changed in the range of 3.36-3.46 during the 6-month storage periods at 9, 22, and 35 ºC. With the increase in storage temperature and time, the titration acidity (TA) decreased compared to the initial values. Soluble solid content (SSC) tended to decrease with increasing storage temperature and time. As the storage temperature and time increased, the L*, a*, b* and C* values of the samples decreased, while the h values increased. The increase in temperature and time in the 6-month storage period caused a significant decrease in total phenolic content (TPC), total monomeric anthocyanin (TMA) and antioxidant activity values. The losses in the amount of TMA were measured as 36.53%, 70.74% and 91.46% in the samples stored at 9, 22, and 35 ºC, respectively. According to the kinetic data, the degradation of crab apple anthocyanins occurred according to first-order reaction kinetics during storage. The rate constants of the samples stored at 9, 22, and 35 ºC were determined as 2.6×10^-3 day^-1, 6.5×10^-3 day^-1 and 12.9×10-3 day^-1, respectively. The addition of crab apple juice concentrate to strawberry marmalades increased the color intensity and anthocyanin stability that decreased during production and storage, and made the product functional.