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The inhibitory effects of phytic acid (PA) on the browning of fresh-cut chestnuts and the associated mechanisms of PA on polyphenol oxidase (PPO) and peroxidase (POD) activities were investigated. The enzymatic browning of chestnut surfaces and interiors was suppressed by soaking shelled and sliced chestnuts in a PA solution. The specifi c activities of PPO and POD extracted from chestnuts declined due to inhibition by PA. PA was determined to be a competitive inhibitor of both PPO and POD by Lineweaver-Burk plots. The binding modes of PA with PPO and POD were analysed by AutoDock 4.2.Keywords: phytic acid, chestnut, enzymatic browning, polyphenol oxidase, peroxidaseChestnut has been a valuable food resource for centuries for the people living in East Asia, South Europe, and North Africa (GOUNGA et al., 2008). Chinese chestnut (Castanea mollissima Blume) is popular in East and Southeast Asia because of its delicious, sweet taste. Research on the chemical composition of chestnuts reveals the presence of various nutrients that are important for human health (DE VASCONCELOS et al., 2010;BLAIOTTA et al., 2012). In the processing of chestnut fruit, it will darken after peeling, mechanical damage, segmentation, grinding, and prolonged exposure due to enzymatic browning. The browning reaction decreases both the acceptability and nutritional quality of chestnuts (DE LA ROSA et al., 2011). Enzymatic browning involves the activities of polyphenol oxidase (PPO) and peroxidase (POD), which oxidize phenols found in fruit and vegetables to anthraquinones, which then become melanins by non-enzymatic polymerization. Controlling the activity of PPO and POD is a potential strategy for the inhibition of enzymatic browning (ZHOU et al., 2015). Effective inhibitors are necessary, because traditional methods, such as heating and adjusting pH value, are impractical in chestnut fruit pretreatment. Phytic acid (PA) is an antioxidant, chelating agent, and non-toxic food additive that has been used to inhibit enzymatic browning of apple juice and asparagus lettuce (CHEN et al., 2010;DU et al., 2012). The present study investigated the effects of PA on the enzymatic browning by inhibiting PPO and POD activities in fresh-cut Chinese chestnuts. Additionally, the inhibition modes and binding sites between PA and PPO and POD were determined.