Comparative study of crude and refined kenaf (Hibiscus cannabinus L.) seed oil during accelerated storage

Sook-Chin Chew; Chin-Ping Tan; Kar-Lin Nyam

doi:10.1007/s10068-017-0009-2

Comparative study of crude and refined kenaf (Hibiscus cannabinus L.) seed oil during accelerated storage

Food Sci Biotechnol. 2017 Feb 28;26(1):63-69. doi: 10.1007/s10068-017-0009-2. eCollection 2017.

Authors

Sook-Chin Chew¹, Chin-Ping Tan², Kar-Lin Nyam¹

Affiliations

¹ 1Department of Food Science and Nutrition, Faculty of Applied Sciences, UCSI University, 56000 Kuala Lumpur, Malaysia.
² 2Department of Food Technology, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia.

Abstract

This study assessed the changes of antioxidant activity and bioactive compounds of crude and refined kenaf seed oil during accelerated storage at 65°C for 24 days. 2,2-Diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assays were used to determine their antioxidant activity. The changes of phenolic, tocopherol, and phytosterol contents during the storage were also studied. The phenolic content and antioxidant activity of refined oil were significantly lower than those of crude oil after the accelerated storage. There was a decrease of 72.5% tocopherol content and 31.1% phytosterol content in the crude oil and a decrease of 67% tocopherol content and 12.1% phytosterol content in the refined oil during the accelerated storage. There was no significant difference in tocopherol and phytosterol contents for crude and refined oils after the storage. The rate of degradation of tocopherol and phytosterol contents in refined oil was slower than that in crude oil during the storage.

Keywords: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assay; 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay; phenolic contents; phytosterol; tocopherol.