In today's fast-paced lifestyle, demand for fresh, natural, and convenient foods has risen sharply, driving the popularity of fresh-cut fruits and vegetables (Liu et al., 2018; Wang et al., 2015). However, fresh-cut processing disrupts cellular membranes, altering the distribution of PPO and phenolic compounds. In the presence of oxygen, they interact to initiate enzymatic browning, producing quinones (Derardja et al., 2022; Hunter et al., 2017). Quinones subsequently polymerize into brown pigments, causing quality deterioration in fresh-cut produce (Sun et al., 2018).

Enzymatic browning occurs not only at the cut surface but also in inner tissues, as observed in fresh-cut eggplants and sweet potatoes. This phenomenon may result from stress signaling in intact tissues triggered by cutting damage, which induces a defensive response (Dovene et al., 2019; Mishra, Gautam, & Sharma, 2012). Several studies indicated that resistance-related hormones regulate enzymatic browning in fruits and vegetables. For instance, methyl jasmonate promotes browning, while SA can inhibit it by enhancing antioxidant capacity and stabilizing membranes (Zhang et al., 2023; Zhou et al., 2019). SA enhances reactive oxygen species (ROS) scavenging, reduces ROS accumulation and membrane lipid degradation, and thus preserves membrane integrity while inhibiting browning in fresh longan (Zhang et al., 2023).

Previous studies have investigated a wide range of strategies to inhibit enzymatic browning in potatoes, which can be broadly classified into chemical, physical, and biological approaches (Sui, Meng, Dong, Fan, & Wang, 2023). Chemical inhibitors, such as sulfites, ascorbic acid, citric acid, and other reducing agents or chelators, have been widely used because they directly inhibit PPO activity or reduce quinones to their corresponding phenolic precursors (Fan, 2023). However, their practical application is limited by adverse effects on flavor and color stability, potential nutritional losses, regulatory restrictions, and growing consumer concerns about synthetic additives and food safety (Carocho, Barreiro, Morales, & Ferreira, 2014).

Physical treatments, including blanching, thermal processing, modified atmosphere packaging, ultraviolet irradiation, and high-pressure processing, have also been applied to control enzymatic browning by inactivating PPO or limiting oxygen availability (Sui et al., 2023). Despite their effectiveness, these methods often require specialized equipment and high energy input, may adversely affect texture and nutritional attributes, and are difficult to standardize or scale up for industrial fresh-cut potato processing (Barrett, Beaulieu, & Shewfelt, 2010).

Biologically derived inhibitors have attracted increasing attention as safer alternatives to chemically synthesized anti-browning agents. Several plant extracts and food-derived compounds have been reported to suppress enzymatic browning in potatoes through inhibition of PPO activity (Aksoy, 2020; Zhang et al., 2025). However, many natural extracts show limited efficacy, often requiring high application concentrations, and some possess inherent pungent or food-incompatible odors, thereby restricting their practical application. Sulfhydryl-containing amino acids, such as L-cysteine, as well as other food-derived amino acids, exhibit browning-inhibitory effects (Song et al., 2023; Zhou, Xiao, Meng, & Liu, 2018); however, challenges related to odor, stability, and application range remain unresolved.

Therefore, identifying a safe, effective, odor-free, biologically derived anti-browning agent and systematically elucidating its regulatory mechanisms at both physiological and molecular levels represent a critical research gap. Addressing this gap would provide a more sustainable and consumer-friendly strategy for controlling enzymatic browning in the fresh-cut potato industry.

Curcumin is a polyphenolic compound regarded as safe and widely used in foods and dietary supplements (Sharifi-Rad et al., 2020). It possesses antioxidant and anti-inflammatory properties that help enhance immunity (Peng et al., 2021). Curcumin reduces lipid peroxidation by sustaining high activities of the antioxidant enzymes superoxide dismutase and catalase (Deng, Zhao, He, & Tian, 2023). Moreover, SA influences curcumin biosynthesis. Exogenous SA application induces the expression of curcuminoid biosynthesis-related genes (CzDCS and CzCURS 1–3) and promotes curcumin accumulation in Curcuma zedoaria cells (El Sherif, Alkuwayti, & Khattab, 2022).

Interestingly, cutting damage increases ROS levels and enhances membrane lipid peroxidation, leading to cell membrane degradation (Wang et al., 2023). This process triggers enzymatic browning, resulting in brown pigment formation and quality loss (Arnold & Gramza-Michałowska, 2022). Therefore, many browning inhibitors reduce browning in fresh-cut products by enhancing antioxidant capacity (Kenny and O'Beirne, 2010, Ru et al., 2020). But the role of curcumin in enzymatic browning of potatoes remains unclear.

In this study, fresh-cut potatoes were used to investigate the effect of curcumin, which effectively inhibited browning. The underlying mechanism of curcumin's browning inhibition was further elucidated. This study identifies curcumin as a novel biogenic browning inhibitor and provides a reference for developing other biogenic browning inhibitors.