Interaction of antioxidants and organic acid from noni (Morinda citrifolia L.) juice with ion exchange resins during deodorization via deacidification

摘要

The unpleasant odour of noni (Morinda citrifolia L. ) fruit has been a longstanding problem which is ca used by octanoic acid. Deodorization of that compound have been performed using deacidification process. Deaci dification of the octanoic acid using ion exchange resin was a ble to reduce the unpleasant odor but resulted in a reduction of beneficial antioxidant activities. Thus, this study was conducted to determine the effects of differen t types and weight of resin on the adsorption of octanoic acid and ant ioxidant compounds in noni juice during deacidifica tion. Three types of weak base anion exchange resins (Amberlite IRA 67, Duolite A7 and Amberlite IRA 96) of differ ent resin weight (0, 5, 10%, w/v) were used. The treated noni juice was analyzed for pH, antioxidant activity, t otal phenolic content (TPC), individual phenolic compounds and oc tanoic acid content. Deacidification of noni juice using the resins significantly (p0.05) decreased the octanoi c acid content compared to fresh juice where Amberl ite IRA 67 gave the maximum reduction of octanoic acid followe d by Duolite A7 and Amberlite IRA 96. The results i ndicated that deacidification of noni juice using 10% of res in weight (w/v) gave higher percentage of antioxida nt activity (DPPH and FRAP) and total phenolic content (TPC). R esults also showed a similar trend when different w eight of resin was used where Amberlite IRA 67 Duolite A7 Amberlite IRA 96 for DPPH, FRAP, TPC and antioxida nt compounds.