Induction of Resveratrol Biosynthesis in Grape Skins and Leaves by Ultrasonication Treatment

Abstract

Abstract. Grapes (Vitis vinifera) are one of the most important fruits worldwide and are eaten raw or after conversion to jelly, jam, juice and wine. Grape skins are a major source of resveratrol (3,5,4′-trihydroxystilbene), which has the ability to reduce blood sugar as well as anticancer, anti-inflammatory, and other beneficial cardiovascular effects. In this study, we investigated the increased accumulation of resveratrol in grape skin and leaves following ultrasonication treatment, which has been shown to induce resveratrol accumulation in several plants. Various ultrasonication treatment times and incubation periods were employed to identify the optimum conditions for the maximum accumulation of resveratrol. Treatment and further incubation led to increased resveratrol in both grape skins and leaves, with the highest increases of 7.7-fold and 1.9-fold occurring in response to 5 min ultrasonication treatment followed by 6 hour incubation and 15 min ultrasonication treatment followed by 3 hour incubation, respectively. The underlying mechanism for the increased amounts of resveratrol were studied by employing a semi-quantitative RT-PCR to monitor the expression levels of the resveratrol synthase (RS) gene in response to ultrasonication treatment. The RS gene increased the expression in response to ultrasonication treatment, suggesting that up-regulation of the RS gene by ultrasonication treatment triggers increased amounts of resveratrol. Taken together, these data indicate that this simple ultrasonication treatment of grapes can be an efficient post-harvest technology for increasing resveratrol in grape skins in addition to cleaning the fruits.

Ultrasound in the postharvest treatment of grapes: impact on the extractability and phenolic composition of juice and wine

“…Comarella et al (2012) in their study on the effects of US application in grapes suggested that an 83% increase in phenolic compounds in the juice were due to the elicitor effect of US. Hasan and Baek (2013) also demonstrated that application of US in grapes led to trans-resveratrol accumulation in the fruit peel. This result was positively correlated with the increase in the expression of resveratrol synthase gene, suggesting that upregulation of the gene and the consequent increase in the enzyme activity by US treatment was responsible for the increase in trans-resveratrol content.…”

“…Previous studies have shown that postharvest application of US increased the content of phenolic substances in peanuts (RUDOLF; RESURRECCION, 2005;SALES;RESURRECCION, 2009) and romaine lettuce (YU et al, 2016). Few studies on grapes have demonstrated the effect of US in increasing resveratrol production in the fruit BAEK, 2013), as well as the enrichment of the juice and other phenolic substances (HASAN et al, 2014;COMARELLA et al, 2012).…”

The stilbene profile in edible berries

“…13) (Hasan and Baek 2013). A significantly higher amount of E-resveratrol over that in the control sample was observed following ultrasonication treatment.…”

Preparation of resveratrol-enriched and poor allergic protein peanut sprout from ultrasound treated peanut seeds

“…Most of recent studies found a higher resveratrol concentration achieved when peanuts treated with ultrasound using different parameters [10,28]. In addition, ultrasound has been used to increase resveratrol content in fruits, such as grape skin and grape juice [12,29]. Therefore, in this study we applied the ultrasound treatment to prepare resveratrol-enriched peanut sprout using different peanut varieties.…”