Postharvest induction modeling method using UV irradiation pulses for obtaining resveratrol-enriched table grapes: a new "functional" fruit?

J Agric Food Chem. 2001 Oct;49(10):5052-8. doi: 10.1021/jf010366a.

Abstract

A modeling method for the induction of resveratrol synthesis by UV irradiation pulses in Napoleon table grapes is proposed. The method is based on the combination of four main parameters: irradiation power (IW), irradiation time (IT), irradiation distance (ID), and number of elapsed days to achieve the highest resveratrol accumulation (D(m)). Maximum resveratrol content (11-fold higher than untreated grapes) was achieved using the combination: IW = 510 W, IT = 30 s, ID = 40 cm, and D(m) = 3 days. Sensory characteristics and main features of irradiated grapes (color, weight, firmness, flavor, size, ripening index and vitamin C content) remained unaltered after 1 week of storage. UV induction signal migrated to the hidden side of the grape skin with a delay of 3 days as compared to the directly irradiated side. Phenolic compounds were not detected in Napoleon grape flesh. Resveratrol content per standard serving (200 g) of irradiated grape was about 3 mg, an amount more than 10-fold higher than that of untreated Napoleon grapes. This means that a serving of irradiated grape (unpeeled) could supply the resveratrol content equivalent to 3 glasses of a red wine with high resveratrol content ( approximately 1 mg/glass). Therefore, controlled UV irradiation pulses are useful as a simple postharvest treatment (and alternative to genetic engineering) to obtain possible "functional" grapes (with enhanced health-promoting properties) as a dietary source of high resveratrol content.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anthocyanins / analysis
  • Ascorbic Acid / analysis
  • Chromatography, High Pressure Liquid
  • Diet
  • Food Technology
  • Health Promotion
  • Kinetics
  • Models, Theoretical
  • Phenols / isolation & purification
  • Resveratrol
  • Sensation
  • Stilbenes / analysis
  • Stilbenes / metabolism*
  • Ultraviolet Rays*
  • Vitis / chemistry
  • Vitis / metabolism*
  • Vitis / radiation effects*

Substances

  • Anthocyanins
  • Phenols
  • Stilbenes
  • Ascorbic Acid
  • Resveratrol