Changes in the Phenolic Content and Free Radical-scavenging Activity of Vacuum Packed Walnut Kernels during Storage

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Bakkalbaşı E. , Yilmaz O. M. , Yemis O., Artik N.

FOOD SCIENCE AND TECHNOLOGY RESEARCH, vol.19, no.1, pp.105-112, 2013 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 19 Issue: 1
  • Publication Date: 2013
  • Doi Number: 10.3136/fstr.19.105
  • Page Numbers: pp.105-112


In this study, the effects of storage temperature, O-2 permeability of packaging materials and variety on phenolic content and free radical-scavenging activity of vacuum-packaged walnut kernels were studied over a 12 months storage period. Methyl gallate (23.70 - 93.75 mg/kg), ellagic acid (137.95 - 569.22 mg/kg), and an ellagic acid pentoside (270.59 - 637.17 mg ellagic acid equivalent/kg) were identified in walnut varieties. While a slight decrease in the amount of ellagic acid was observed during 12 months storage, decreases in the amount of ellagic acid pentoside, total phenolic content and free radical-scavenging activity were severe. The present study concluded that it is possible to protect the phenolic content and antiradical activity of walnut kernels by packaging in Polyamide/Polyethylene laminate pouches having an oxygen permeability lower than 63.40 +/- 0.40 (mL/m(2)/24h at 23 degrees C) under vacuum at 20 degrees C up to twelve months.