Physicochemical properties, phenolic acids and volatile compounds of oil extracted from dry alhydwan (&lt;em&gt;Boerhavia elegana Choisy&lt;/em&gt;) seeds

H Zhang,A Al-Farga,M V.M Chamba,Q A Nabil,A Siddeeg

doi:10.3989/gya.0944142

Abstract

In this study, the chemical composition, physicochemical properties, phenolic acids and volatile compounds of alhydwan (Boerhavia elegana Choisy) seed oil were evaluated. The crude oil content was 11.49%, ash 6.88%, moisture 6.12%, protein content 14.60%, total carbohydrate 24.77% and fiber 36.13%. The oil contain a high quantity of unsaturated fatty acids (74.63 mg·100 g−1) with oleic (C18:1) (57.77%), palmitic (C16:0) (18.65%) and linoleic (C18:2) (12.88%) acids as the most abundant. The relative density was 0.88 and the iodine value 105.59. The color analysis showed a value of 28.33 Y+1.43 R. The oil also had a high relative oxidative stability. The tocol composition showed that α-tocotrienol, γ-tocopherol and γ-tocotrienol were in a higher concentration than the rest. Seven phenolic acids (caffeic, vanillic, galic, p-coumaric, ascorbic, cinnamic and ferulic) were detected, with ascorbic acid as the predominant one (5.44 mg·100 g−1). In relation to the volatile composition, 48 compounds were found with Z-10-Pentadecen-1-ol (56.73%); Hexadecenoic acid, Z-11- (18.52%); 9,12-Octadecadienoic acid (Z,Z)- (3.93%) and 9,12-Octadecadienoic acid (Z,Z)-, 2-hydroxy-1-(hydroxymethyl) ethyl ester (3.04%) as the most abundant. These findings demonstrated the potential of alhydwan seeds to be used as a good source of quality edible oil.

Highlights

Due to the ever-increasing demand for and price of edible oils, a number of explorations are being made to discover more edible oils, more especially those extracted from plant sources (Sbih et al, 2013)
The world consumption is dominated by palm, soybean, rapeseed and sunflower oils with 38.1, 35.7, 17.8 and 18.2 million tones consumed per year, respectively (American Soybean Association, 2007) with world interest still on the recovery and exploitation of oils from more natural plant resources (Jelassi et al, 2014)
Alhydwan (Boerhavia elegana Choisy) is one of the edible herbaceous plants, a type of Boerhavia that belongs to the Nynctaginaceae family, commonly available in South Yemen (Boulous, 1988)

Summary

Introduction

Due to the ever-increasing demand for and price of edible oils, a number of explorations are being made to discover more edible oils, more especially those extracted from plant sources (Sbih et al, 2013). In recent years there has been an increased important exploitation of promising plant species as a source of dietary or specialty oils (Jelassi et al, 2014). Alhydwan is cultivated only in Yemen and is not well known even in its neighboring countries It has a long history of uses by indigenous and tribal people there in the traditional cuisine of as one of the staple ingredients in the manufacture of porridge, desserts and savory products. The present study aimed at examining these particular aspects The knowledge of these properties may lead to the innovative use of alhydwan seed oil for food and other industrial purposes

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Results

Conclusion