Abstract: This study aimed to analyze the effect of high temperature steaming pretreatment on chemical components of Phyllanthus emblica L. juice and to elucidate its browning behavior during storage. Juices prepared from the fruit subjected or not to the pretreatment (designated as samples D and W, respectively) were stored for up to 42 days at different temperatures. Changes in the concentrations of vitamin C, total phenols, 5-hydroxymethyl furfural (5-HMF) and reducing sugar along with browning degree (BD) were examined during the storage period, and path analysis was employed to explore the main causes of browning. The results indicated that high-temperature steaming pretreatment could slow the loss of vitamin C, total phenols and total sugar, and reduce the production of 5-HMF and the BD of Phyllanthus emblica L. juice under all tested storage conditions. In addition, low-temperature storage was beneficial for retaining nutrients in the fruit juice. High-temperature steaming pretreatment changed the main causal factors of browning during its storage. For sample W, total phenol concentration had the largest direct impact on BD, and the interaction between total phenol and 5-HMF concentration was the chief determinant of browning at 4 ℃. For sample D, 5-HMF concentration had the largest direct impact on BD, and the interaction between 5-HMF and total phenol concentration was the chief determinant of browning at 4 ℃. At 25 ℃, the browning of Phyllanthus emblica L. juice was mainly dependent on total phenol concentration for both samples. At 37 ℃, total phenol concentration had the largest direct impact on BD and was the chief determinant of browning for sample W, while for sample D, vitamin C had the largest direct impact on BD and the interaction between vitamin C and 5-HMF concentration was the chief determinant of browning.

Key words: Phyllanthus emblica L. juice, storage, browning, path analysis