Organic versus conventional 'Willamette' raspberry: yield, bioactive compounds and antioxidant properties

Abstract

This paper presents the results of a two-year trial on the yield, total phenolic and flavonoid contents and total antioxidant capacity of the 'Willamette' red raspberry under organic and conventional farming. A trial was conducted in a commercial plantation of 'Willamette' raspberries located in the southwestern part of Serbia. The total phenolics and flavonoids in the raspberry fruits were determined by the Folin-Ciocalteu reagent and aluminium chloride assay, respectively. The ferric reducing antioxidant power assay was used to evaluate the total antioxidant capacity of the raspberry fruits. The results of this study showed that the raspberry yields were significantly affected by the different farming systems. The raspberry yield in conventional farming was higher than that of organic farming. Contrastingly, the raspberries from the organic farming contained higher levels of the total phenolics and flavonoids and also had a higher total antioxidant activity compared to those from the conventional farming in both 2021 and 2022. This study also showed that the total phenolic and flavonoid contents of the 'Willamette' red raspberry have a significant and positive correlation with their total antioxidant capacity, indicating that the phenolic compounds play an important role in the antioxidant activity of the raspberry.

Keywords

• environment
• fertilisation
• fruits
• health
• plant protection