Preparation of Kojic Acid-Sodium Alginate Film Coating and Its Effects on the Browning of Lily Bulbs

In order to develop active packaging of lily products,L₉(3⁴)orthogonal array design(OAD)was evaluated and verified the optimum condition of the three factors(sodium alginate,glycerinum and kojic acid concentration),and the browning inhibition effect of the composite coating on the lily bulbs stored at 4 ℃ for 15 days was studied. Results showed that the best concentrations of sodium alginate(SA),glycerinum and kojic acid(KA)were 8 g/L,0.3% and 1.0 g/L. At the same time,PLA/SA composite films treatment inhibited browning degree and microbial growth. Compared with the control,polyphenol oxidase(PPO),peroxidase(POD)and phenylalnine ammonialyase(PAL)activities of KA/SA composite films treated lily bulbs were reduced by about 31%,21% and 29% after being soaked in composite membrane respectively. Total phenolic and quinone contents were decreased by 16% and 15%. KA/SA composite films treatment prevented the decrease of the firmness and the rise of MDA contents. These results indicated KA/SA composite coating could effectively inhibit the browning and maintain the quality of lily bulbs.