Effectiveness of ascorbic acid and sodium metabisulfite as anti-browning agent and antioxidant on green coconut water (Cocos nucifera) subjected to elevated thermal processing

Thermal processing of green coconut water (GCW) caused non-enzymic browning and development of rancidity. Effect of the addition of several combinations of ascorbic acid (AA) (0 to 100 ppm) and sodium metabisulfite (SMB) (0 to 30 ppm) on brown discolouration and rancidity of GCW during elevated thermal processing (121°C for 5 min at 15 psi) was investigated. Addition of AA and/or SMB significantly (P<0.05) reduced brown discolouration of processed GCW, with SMB being approximately 7 times more effective than AA. Rancidity in GCW was significantly (P<0.05) reduced with the addition of SMB and/or AA, with SMB being the most effective; approximately 35 times more effective than AA, respectively. SMB can be recommended as an effective controller of browning and rancidity in thermally processed GCW.