Abstract: In this paper, the separate and combined effects of chlorine dioxide (ClO2) sterilization and chitosan oligosaccharide (COS) coating on bacterial growth inhibition, polyphenol and lignin content, lignin accumulation rate, phenylalanine ammonialyase (PAL) activity and peroxidase (POD) activity in fresh waxy corn during storage were compared. It turned out that the combination of 200 mg/L ClO2 and 15 mg/mL COS exhibited a good inhibitory effect on pathogen infection. After 35 d of storage, total mold and yeast count in the combined treatment group was (2.30 ± 0.12) (lg(CFU/g)), which was significantly lower than that in the ClO2 ((3.78 ± 0.16) (lg (CFU/g))) and COS ((4.18 ± 0.09) (lg(CFU/g))) treatment groups (P < 0.05). The combined treatment could reduce lignin accumulation rate, and reduce and maintain polyphenol content to a low level. Furthermore, the combined treatment inhibited the rapid increase of PAL activity and reduce the level of phenylpropane metabolism. It could also reduce POD activity and keep it at a low level during storage, thus reducing lignin accumulation.

Key words: fresh waxy corn (Zea mays L.), pathogen infection, phenylpropanoid metabolism, lignin accumulation, ClO2, chitosan oligosaccharide