Effects of silver nanoparticle (AgNP), putrescine and their combined applications on postharvest quality and biochemical properties of seben siyahi grape variety

Seben Siyahı grapes are an agricultural product that attracts attention in the market especially during certain periods due to their short post-harvest life and limited availability. Various innovative approaches have been developed to improve the quality and shelf life of grapes after harvest. In this study, the effects of putrescine (0.5 mM), silver nanoparticles (50 ppm) and the combined applications of these two substances in maintaining the post-harvest strength and quality of Seben Black grape variety were investigated. In addition, pure water was used as a control. The study results showed that weight loss was less than the control in all applications, but this decrease was not statistically significant. A similar situation was observed for the amount of water-soluble dry matter. pH and titratable acidity also followed similar trends, but the changes in these properties were found to be statistically significant. Color values remained relatively stable and were not significantly affected by the applications. The effects of the applications on total contents were only effective on anthocyanins, while the effects on protein, carbohydrate and flavonoid amounts were found to be insignificant. However, the application x storage period interaction on protein and flavonoid amounts exhibited significant effects. All antioxidant activities except DPPH reduction activity were significantly affected by the applications. In addition, significant increases were observed in antioxidant activities as storage time increased. The opposite situation occurred in enzymes, and while the amounts of antioxidant enzymes decreased as storage time increased, oxidative enzymes increased in parallel with storage time. In conclusion, this study revealed that the application of putrescine together with naogümüş is a preferable approach in the storage of grapes and its effects on biochemical and enzymatic activities.