Enzymatic browning is associated to the colour alteration and phenolic degradation of minimally-processed fruits and vegetables. The main responsible is polyphenol oxidase (PPO, EC 1.14.18.1), a copper-containing oxidoreductase which catalyzes two different enzymatic reactions involving oxygen and polyphenolic substrates which are polymerized to dark pigments. Since the control of PPO activity is until now an open question in the agro-food industry, the search for new anti-browning strategies is moving towards replacing conventional treatments. The present review is aimed to discuss non-thermal technologies and natural inhibitors considering their anti-PPO impact in relation to enzyme source, processing conditions, type and concentration of bioactive compounds. These innovative treatments can be proposed as eco-friendly systems for effectively reducing PPO activity thus preventing enzymatic browning and consequently improving sensory, antioxidant and nutritional properties of fruit and vegetable products.

酶促褐变与最少加工的水果和蔬菜的颜色变化和酚类降解有关。主要原因是多酚氧化酶（PPO，EC 1.14.18.1），一种含铜的氧化还原酶，催化两种不同的酶促反应，涉及氧气和多酚底物，这些底物聚合成深色颜料。由于迄今为止，对PPO活性的控制一直是农业食品行业的一个悬而未决的问题，因此寻求新的抗褐变策略的努力正在朝着取代传统疗法的方向发展。本综述旨在讨论非热技术和天然抑制剂，考虑其与酶源，加工条件，生物活性化合物的类型和浓度有关的抗PPO影响。