|
Abstract
|
BACKGROUND: Grape berries produce significant amounts of phenolic compounds. These are an essential qualitative factor due to their nutritional value and effect on berry color and texture. Salicylic acid (SA) and its derivatives usually lead to enhancement of phenolic content in plant tissues. The present study was conducted to evaluate the effect of different levels of SA (0.0, 50.0, 100.0, and 200.0mM) on the production of phenolic compounds and the derivatives (anthocyanin and flavonoid) in the grape berries, with emphasis onmalvidin-3-O-𝜷 glucoside as a regular anthocyanin in red grapes. RESULT: The results showed that total phenolics contentwere significantly enhanced in SA-treated (100.0 and 200.0mM) berries compared to untreated ones. Salicylic acid treatment at all concentrations considerably improved the anthocyanin content in the berries and, comparedwith untreated berries, the accumulation ofmalvidin-3-O-𝜷 glucosidewas higher in SA-treated fruits. In particular, the 200.0mMconcentration caused approximately two times more malvidin-3-O-𝜷 glucoside than the control. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity of the fruits treated with SA were significantly higher than those of theuntreated berries. The activity of phenylalanine ammonia-lyase (PAL) inSAtreated fruits significantly increased as compared with the untreated clusters. CONCLUSION: A general evaluation of the current results leads us to the conclusion that SA is a suitable and recommendable treatment for improving and increasing the phenolic and antioxidant capacity of grape berries. Spraying grape berries at pre-véraison stage with SA could therefore be a convenient strategy to increase quality and nutritional value of grape berries considerably.
|