Effect of Ultrasound as Abiotic Elicitor on the Production of Trans-Resveratrol in Vitis vinifera L.
Special Symposium - Innovations in Food Technology (LMC Congress)
Process & Product Innovation (Food-4b)
Keywords: trans-Resveratrol; ultrasound; Vitis vinifera L.(Kalecik Karasi); antioxidant; abiotic elicitor
Abstract
Phytoalexins are organic metabolites that are produced by plants in response to biotic elicitor (e.g. fungal infection) or abiotic elicitor such as UV light, heavy metal ions or ultrasound (1). Resveratrol (trans-3,5,4’-trihydroxystillbene) is one of the most important phytoalexins. It is synthesised particularly in the skins and seeds of grape berries and only trace amounts are present in the fruit flesh (2).Resveratrol exists in two isomeric forms, cis- and trans-; the trans-isomer is present in the skins of Vitis vinifera L., but the cis- isomer has not been reported (3). Resveratrol was first reported in the skins of grape berries for disease resistance and later in wines to benefit health (4). A strong antioxidant property of trans-resveratrol is emphasized in medicine and pharmacy literature. Resveratrol possesses antibacterial and antifungal activities and induces platelet hypoaggregation in rats; it protects liver from the lipidic peroxidation and inhibits the oxidation of low density lipoproteins (LDLs), modulating its metabolism. Recently, it is carcinopreventive activity has been proved (5). In a study explaining the effect of ultrasound to the peanut kernels (slicing 2 mm), ultrasound exposure for 4 min at 25 0C, and incubation for 36 h produced the highest level of trans-resveratrol in peanuts. Trans-resveratrol concentrations increased from 0.48 ± 0.08 µg/g to 3.96 ± 0.96 µg/g (6). Studies investigating the effect of ultrasound to trans-resveratrol synthesis in grapes are very limited.
In this study the effect of ultrasound as an abiotic elicitor on the production efficiency of trans-resveratrol in Vitis vinifera L. (Kalecik Karasi cultuvar- clone 15) was investigated. Ultrasound was given into the system by the application of pulse and continuously ultrasonic irradiation at 20 and 30 kHz. A cylindrical glass reactor with jacket (100 mL) was used. Trans-resveratrol was analyzed by HPLC. The parameters were chosen as freezing (-20 oC), ultrasound application types (continuous or pulse; 0.5 s on/ 0.5 s off and 0.1 s on/ 0.9 s off), ultrasound application time (10 min or 1 h) and incubation times (0, 24 h, 48 h and 72 h) and frequency (20 kHz and 30 kHz).
It was found that the most effective incubation time was 48 hours independently from ultrasound application types/time and frequency. The pulse (0.5 s on, 0.5 s off) application of ultrasound was more effective than continuous application. Moreover, pulse (0.1 s on, 0.9 s off) application of ultrasound was more effective than pulse (0.5 s on, 0.5 s off ) application. The maximum trans-Resveratrol concentration obtained by ultrasonic irradiation in pulse mode (0.1 s on, 0.9 off) for 1 hour in the incubation time of 48 hours at 20 kHz was 1.1 ppm. The similar results were also found at 30 kHz for the same conditions. Ultrasound application at 30 kHz was given higher trans-Resveratrol concentration than that of 20 kHz during 10 minutes and 1 hour. It was found that the trans-Resveratrol concentration increased 15 fold (from 0.14 ppm/unirradiated grape to 2.1 ppm/irradiated grape) according to nonirradiated samples by ultrasonic irradiation at 30 kHz using in Kalecik karasi clone 15 (frozen). The trans-Resveratrol concentrations were similar for fresh or frozen samples before they were irradiated. The trans-Resveratrol concentrations did not seriously change using fresh samples for 10 min and 1 hour.
References
1. Adrian, M.,Jeandet, P.,Bessis,R.and Joubert, M.J.1996. J.Agric. Food Chem. 44:1979- 1981
2. Becker JVW,Armstrong GO,Van der Merwe MJ et.al.,2003.FEMS yeast research. 4(1):79-85
3. M.C.Pascual-Marti,A.Salvador,A.Chafer,A.Berna ,2001.Talanta 54: 735-740
4.Lei C.,Yashan H.,Fuquan Y.,Tianyou Z.,2001.Journal of Chromatography A, 907: 343-346
5. O.Palomino, M.P. Gomez-Serranillos, K.Slowing et.al.,2000. J.of Chromatography A,870:449-451
6. Jamıe R. Rudolf and Anna v. A. Resurreccıon,2005, J. Agric. Food Chem. 53,10186-10192
Acknowledgements
The authors gratefully acknowledge the financial supporting of this work by Ankara University,
Institute of Biotechnology (Turkey) (Project No: 2005-163).
Presented Thursday 20, 10:20 to 10:25, in session Process & Product Innovation (Food-4b).
