APPLICATION OF RESPONSE SURFACE METHODOLOGY TO PREDICT THE OPTIMAL CONDITIONS FOR REDUCING BROWNING IN THE IN VITRO CULTURE OF MUSA (AA GROUP) ‘KLUAI KHAI’ PLANTLETS

One of the major problems of Musa (AA group) ‘Kluai Khai’ tissue culture is the browning from the oxidation of phenolic compounds. This problem can be resolved by adding antioxidants or phenolic–adsorbing agents to the culture medium. A response surface methodology (RSM) approach was employed in combination with a central composite design (CCD) to model the effects of three factors: ascorbic acid (AA), polyvinylpyrrolidone (PVP), and activated charcoal (AC), each at three concentration levels. A total of 17 experimental treatments were conducted for 12 weeks. The levels of phenolic compounds, tannins, and flavonoids in the culture medium were analyzed, and the four treatments yielding the lowest concentrations were selected for further validation. The optimized conditions were subsequently tested for 12 weeks. The results indicated that Murashige and Skoog (1962) medium supplemented with 0.03 g/L AA, 3.325 g/L PVP, and 1.48 g/L AC effectively reduced browning in in vitro cultures of Musa (AA group) ‘Kluai Khai’.