Changes in Antioxidant Capacity of Apples Stored Under Controlled Atmosphere

The storage of apples under controlled atmosphere conditions is a widely used strategy to extend shelf life and preserve nutritional quality. This study aimed to evaluate the impact of six months of dynamic controlled atmosphere storage (0.5% O2, 1% CO2) at 1ºC on the antioxidant capacity of Fuji Aztec and Gala Redlum apple cultivars. Four assays were conducted post harvest and after six months of storage: DPPH radical scavenging, β-carotene bleaching, total phenolic content, and total flavonoid content.

The results showed a slight decrease in phenolic content (–17% on average), reflecting the partial degradation of phenolic compounds over time. However, the TFC increased significantly (+69%), suggesting a possible release of bound forms during storage. The DPPH radical scavenging capacity increased by 13% on average, indicating that the overall antioxidant potential was maintained or even improved for some cultivars, despite the reduction in TPC. In contrast, the β-carotene bleaching inhibition capacity showed a tremendous decline (–80%).

These findings suggest that controlled atmosphere storage can effectively maintain certain aspects of antioxidant activity in apples, although the protective effect against lipid oxidation may be compromised. Understanding these dynamics is essential to optimise postharvest handling strategies and to provide consumers with fruits that retain their bioactive properties for longer periods. Further studies could focus on identifying the specific phenolic subclasses responsible for these variations and exploring the influence of different controlled atmosphere regimes on the preservation of functional quality.