Packaging Strategies for Anthocyanin Stability and Nutritional Quality in Postharvest Fruit: Mechanisms and Emerging...

Anthocyanins are key determinants of color, nutritional value, and consumer appeal of many fruits, but are highly susceptible to degradation once the fruit is harvested. In this review, a compilation of recent literature is presented to illustrate how packaging materials and technologies can control these destabilizing factors and consequently maintain anthocyanin integrity. Packaging has been shown not only to change the pigment retention but also to play an active role in modulating the fruit micro-environment. Biopolymer films and coatings, UV and light-blocking encapsulates, nano-reinforced films, and controlled atmosphere systems have shown high potential for the reduction of oxidative stress,  humidity control, as well as moderation of gas exchange and deceleration of enzymatic pathways responsible for pigment degradation. In addition, active packaging using natural antioxidants, pH buffers, and oxygen scavengers improves the chemical conditions for stabilizing anthocyanins. Nano-enhanced materials, including nanocellulose, nano-clays, and metal or metal oxide nanoparticles, also offer increased benefits through enhanced barrier properties as well as strengthening physical stability. However, their use should be considered with regard to safety and regulatory factors of migration and toxicity. Altogether, these developments emphasize a shift towards packaging as a biocontrol device that can alleviate anthocyanin degradation and enhance postharvest fruit quality. Further advances in these areas will be important for color stability, nutritional quality, and consumer preference of anthocyanin-rich fruits from field to fork.