Comparison of total phenols and antioxidant properties of walnut (Juglans regia L.) green husk of three regions of northern Iran (Shahrood, Bandar Gaz and Hzargarib)

Authors
Mohammad Dolat Abadi
Zeinab Raftani Amiri
Reza Esmail Zadeh Kenari
Abstract
Walnut green husk is waste of walnut that can be valuable source of natural compounds with antioxidant properties. In this study, the effect of regions (Shahrood, Bandar Gaz and Hzargarib),solvent (ethanol 96%, Water and ethanol - water (1:1 v/v)) and extraction time (6 to 24 hours) on the yield of extracted phenolic compounds from walnut green husk has been analyzed. Immersion method at room temperature in a factorial experiment with three replications in a completely randomized design has been used. Then, bioactive properties of walnut green husk extract in a completely randomized design have been compared. The total phenol content of the extract was determined by the method of Folin- ciocalteau. Antioxidant activity of the extract by the reducing power of Iron III and DPPH free radical scavenging ability was evaluated. The results of this study showed that, the solvent polarity, time extraction and plant habitat are effective on amount of extracted phenolic compounds; and also antioxidant activity of the extract depends on the concentration of phenolic compounds. The highest phenolic compounds with 49.66 mg/g (based on Galic acid) were achieved from Hezar jerib walnut green husks with water - ethanol solvent (1:1 v/v) for 24 hours. Also, the most antioxidant properties of the extracts were shown in this extract.
Keywords
Key words: Antioxidant properties
phenolic compounds
solvent
Walnut green husks
Journal of food science and technology(Iran)
Volume 11, Issue 45
March 2014
Pages 183-192