The effect of green synthesized nanoparticles on organic acids in strawberry and sweet cherry during storage

This study investigated the effects of boron-, copper-, and chitosan-based nanoparticles (synthesized by the green synthesis method) on organic acid contents of strawberries and sweet cherries during storage. The fruits were dipped in nanoparticle solutions for 2 minutes and stored under cold conditions (0 ± 0.5 °C for sweet cherries, 1 ± 0.5 °C for strawberries) at 90 ± 5% relative humidity. Malic, citric, and oxalic acid levels were evaluated. In strawberries, the Boron1 treatment (500 ppm boron nanoparticle) was the most effective in preserving organic acids, particularly citric acid, which remained at 2431.5 mg kg⁻¹ fw by the end of storage compared to 1702.5 mg kg⁻¹ fw in the control group. In sweet cherries, Chitosan (1% nanochitosan solution) treatment preserved the highest level of malic acid (2256.7 mg kg⁻¹ fw), while Boron1 contributed to the retention of citric acid (20.75 mg kg⁻¹ fw), exceeding even the initial harvest value. Oxalic acid degradation was slowed in the treated groups compared to the control in both fruits. The results suggest that nanoparticle-assisted edible coatings may offer a promising strategy for extending shelf life and partially preserving phytochemical content. Moreover, it was observed that the dominant organic acid varied by fruit species, i.e., citric acid in strawberries and malic acid in sweet cherries. These findings support the view that nanoparticle applications should be tailored to fruit type and may contribute to the development of more sustainable postharvest preservation approaches.