Enzymatic browning and its inhibition in new apple cultivars slices using 4-hexylresorcinol in combination with ascorbic acid

Enzymatic browning in minimally processed apples of new cultivars (i.e. Braeburn, Criterion, Fuji, Gala, Jonagold) was investigated at 2.5, 12 and 20 degrees C, and compared with traditional cultivars (Golden Delicious and McIntosh). Browning inhibition by ascorbic acid (AA) and a mixture of ascorbic acid and 4-hexylresorcinol (AH) was also studied. Among the new cultivars, Jonagold had the slowest browning rate and Braeburn had the fastest rate. Of the two traditional cultivars, McIntosh had the faster browning rate. The temperature sensitivity of the browning varied among cultivars, where Q(10) ranged from 1.3 to 4.4 (calculated from colour parameter a*), and the activation energy (E-a) ranged from 8.0 to 18.3 kcal/mol. The browning rate dependence on temperature was as follows: Fuji < McIntosh < Criterion < Braeburn and Gala < Golden Delicious < Jonagold. Browning was inhibited significantly using AH and AA. The AH treatment resulted in a better inhibition of enzymatic browning for most of the cultivars.