Reduction of Browning Reaction in Aromatic Coconut by using Melatonin and Citronellal

The change of white mesocarp to brown color within a short period is the main problem of trimmed aromatic coconuts. This browning is commercially controlled by sodium metabisulfite (SMB), which affects consumers who are allergic to sulfur compounds. This research studied application of melatonin (MT) or citronellal (CT) to control the browning symptom as a replacement for SMB. Coconut mesocarp pieces sized 4×4.5 cm and 0.5 cm thick were dipped in 1 mM MT and 2% CT solutions for 3 minutes, air-dried, and stored at 4 °C for 3 weeks. Distilled water and 3% SMB were used as controls. The study found that coconut mesocarp pieces dipped in 3% SMB had significantly higher lightness (L* value) than other treatments, following by the mesocarps dipped in CT, MT and the distilled water (control). The used of CT was also effectively delayed fungal growth equal SMB. The mesocarp pieces treated with MT had the highest significant total phenolic content, as compared to other treatments. These results suggest that CT is promising for disease control and browning prevention in coconut mesocarps.