Enzymatic browning seriously influenced the color and nutrition of fruits and vegetables. This study investigated the effect of cinnamon essential oil nanoemulsion (0.1, 0.2, and 0.4%) combined with 0.05% ascorbic acid (AA) on polyphenol oxidase (PPO) activity and related quality of cloudy apple juice. Cinnamon essential oil nanoemulsion was stable in the presence of AA with different concentrations. The individual cinnamon essential oil nanoemulsion showed 80–90% inhibition of PPO activity, which is not enough to effectively control the browning of apple juice. When the cinnamon essential oil nanoemulsion was combined with 0.05% AA, the cinnamon essential oil nanoemulsion acted as a PPO inhibitor and AA acted as a reducing agent, which completely inhibited PPO activity and preserved the color of apple juice during 48 h of storage at 4 °C. In addition, 0.2% and 0.4% cinnamon essential oil nanoemulsion combined with AA reduced the instability index of apple juice from 0.473 to 0.034 and 0.018, respectively. Furthermore, the combined treatment delayed the degradation of total phenol and AA content in apple juice. Collectively, these results indicated that the combination of cinnamon essential oil nanoemulsion and AA could be used to enhance the inhibition of enzymatic browning and maintain the quality of cloudy apple juice.

酶促褐变严重影响了水果和蔬菜的颜色和营养。这项研究调查了肉桂精油纳米乳液（0.1％，0.2％和0.4％）与0.05％抗坏血酸（AA）联合使用对多酚氧化酶（PPO）活性和相关的混浊苹果汁质量的影响。肉桂精油纳米乳液在不同浓度的AA存在下是稳定的。单个肉桂精油纳米乳液显示出80-90％的PPO活性抑制作用，不足以有效控制苹果汁的褐变。当肉桂精油纳米乳液与0.05％AA混合使用时，肉桂精油纳米乳液充当PPO抑制剂，而AA充当还原剂，完全抑制PPO活性并在4 h储存48小时的过程中保留苹果汁的颜色。 ℃。此外，0.2％和0.4％的肉桂精油纳米乳剂与AA组合可将苹果汁的不稳定性指数分别从0.473降低至0.034和0.018。此外，联合处理延迟了苹果汁中总酚和AA含量的降解。总的来说，这些结果表明肉桂精油纳米乳剂和AA的组合可用于增强对酶促褐变的抑制并维持混浊苹果汁的质量。