Evaluation of Shelf Life of Walnut Kernels Treated by Antioxidants and Different Packaging under Two Temperatures

Subject Areas : Food Science and Technology

Roghieh Talebi Habashi ¹ , Shahin Zomorodi ^{2 *} , Alireza Talaie ³ , Sepideh Kalateh Jari ⁴

1 - Department of Horticultural Science and Agronomy, Science and Research Branch, Islamic Azad University, Tehran, Iran
2 - Department of Engineering Research, West Azerbaijan Agricultural, Education and Natural Resources Research Center, AREEO, Urmia, Iran
3 - Department of Horticulture, University of Tehran, Tehran, Iran
4 - Department of Horticultural Science and Agronomy, Science and Research Branch, Islamic Azad University, Tehran, Iran

Received: 2019-05-29 Accepted : 2019-11-30 Published : 2019-12-01

Keywords: Walnut, shelf life, Packaging, antioxidants,

Abstract :

In this study, the effects of coatings made of chitosan (Chi) incorporating thyme essential oil (TEO) on lipid oxidation and changing color indexes of walnut kernels were investigated. Chi: pure, in accompany with TEO at concentrations of 500 and 1000 microliter per liter, in an aqueous coating solution, with different packaging methods: Gunny sack, polypropylene and active packaging, compared with control walnut, were used and stored at 4ºC and 25ºC. The study was performed as factorial experiment based on a complete randomized design. The results showed that amounts of color indexes in treated samples decreased. The samples stored at 4°C contained minimum moisture fluctuations in all packaging methods. The peroxide values and conjugated diene values at 4°C were lower than those at 25°C. Treatments did not have positive effect on free fatty acids of walnut kernels. During the storage, shelf life of walnut kernels prolonged with active packaging and chitosan coating at 4ºC.