Comparison of total phenolic content and antioxidative activities of EU PDO Malatya apricot (Prunus armeniaca L.) kernels

This study investigates the bioactive content of kernels from four apricot varieties: Hacihaliloglu, Hasanbey, Kabaasi, and Zerdali, grown in Malatya over two consecutive years, 2018 and 2019. The research addresses the need to understand how harvest timing and varietal differences influence total phenolic content and antioxidant activity, which are critical for health-related applications. Antioxidant activity was assessed using DPPH, ABTS, and FRAP assays. The findings revealed that sweet apricot varieties Hasanbey, Hacihaliloglu, and Kabaasi exhibited higher total phenolic and antioxidant content than the bitter Zerdali variety. Among these, Hasanbey kernels had the most favorable bioactive profile, while Hacihaliloglu and Zerdali generally exhibited the lowest levels. Harvest timing significantly impacted the bioactive content, except for the FRAP assay results, underscoring the role of developmental stages in kernel quality. Furthermore, year-to-year variations in bioactive content suggest that external factors such as soil composition, climate, and growing conditions also play a critical role. A strong positive correlation was observed between FRAP and both total phenolic and DPPH antioxidant activity, indicating shared reactive compounds. These results highlight the potential of sweet apricot kernels as a bioactive rich resource and underscore the influence of genetic, environmental, and temporal factors on their nutritional value. Keywords: Antioxidant activity; apricot; Prunus aremeniaca L.; total phenolic content