Published in: Food chemistry (2005), vol. 91, pp. 469-476
Statut: Postprint (Author's version)
Heating effects on some quality characteristics of date seed oil
Besbes Souhail1, Blecker Christophe3, Deroanne Claude3, Lognay Georges4, Nour-Eddine Drira2, Hamadi Attia1
1 Unité Analyses Alimentaires,
Département de biologie, Ecole Nationale d'Ingénieurs de Sfax, Route de Soukra B.P.
W., 3038 Sfax, Tunisie.
2 Laboratoire de biotechnologie végétale, Faculté des Sciences de Sfax, Route de Soukra, 3038 Sfax, Tunisie.
3 Unité de Technologie des Industries Agro-alimentaires, Faculté Universitaire des Sciences Agronomiques de
Gembloux, passage des Déportés 2, 5030 Gembloux, Belgique.
4 ...view middle of the document...
We could also expect
that they may have a good shelf life.
Keywords: Date seed oil – heating – oxidation – quality characteristics.
The date (Phoenix dactylifera L.) has always played an important part of the economic and social lives of the people of
arid and semi arid regions of the world. Tunisia is considered to be one of the date producing countries; the number of
these trees is estimated to be over 4 million and around 100,000 tons of dates are produced annually. The fruit of the
date palm is composed of a fleshy pericarp and seed.
Date seeds may have extractible high value-added components. Presently, however, very little use is made of these
components: they are discarded or used in animal feed. Little research has been undertaken on date palm seeds; this has
focused particularly on their chemical composition (Al-Showiman, 1990; Al-Hooti, Sidhu, & Qabazard, 1998;
Devshony, Eteshola, & Shani, 1992; El-Shurafa, Ahmed, & Abou-Naji, 1982; Hamada, Ha-shim, & Sharif, 2002). Date
palm seeds are a waste product of many industries based on the technological transformation of date fruits (Al-Hooti,
Sidhu, Al-Ota-ibi, Al-Ameeri, & Qabazard, 1997; Hobani, 1998; Khat-chadourian, Sawaya, Khalil, & Mashadi, 1983;
Youssif, Abou Ali, & Bou Idreese, 1990; Youssif, Alghamdi, Hamad, & Mustafa, 1996; Youssif & Al-Ghamdi, 1999) or
on their biological transformation (Abou Zied & Baghlef, 1983; Abou Zied, Abderrahman, & Baghlef, 1991; Abou Zied
& Khoja, 1993; Al-Obaidi & Berry, 1976; Nacib, Nacib, & Bourdant, 1997; Nacib et al., 1999). Then, a large quantity
of date seeds could be easily collected from the date processing industries or from the waste products (represent nearly
30% of the production in Tunisia) coming either directly from the palm grove or from the gap-conditioning stations.
It is well known that the average weight of date seeds is about 10-15% of date weight (Almana & Mahmoud, 1994;
Hussein, Alhadrami, & Khalil, 1998). In Tunisia, the lipid fraction of date seeds could amount to over 1000 tons,
assuming a mean proportion of 10% of seed in date fruits and 10% oil content of seeds. Some scientists have studied
chemical characteristics and fatty acid composition of date seed oil. The chemical characteristics of seed oil from six
Libyan date cultivars were as follows: iodine number ~54.8, saponification value ~207 and acid value 1.75 (El-Shurafa
et al., 1982). The major fatty acid found in date seed oil was oleic acid (Al-Showiman, 1990; Devshony et al., 1992).
Fair amounts of lauric acid, myristic acid and palmitic acid ranging between 15.4% and 23.8%; 7.42% and 11.8%,
6.96% and 10.2% were also observed (Al-Showiman, 1990). In a previous paper, we reported that the oxidative stability
of date seed oils was higher than that of most vegetable oils and comparable to that of olive oil (Besbes, Blecker,
Deroanne, Drira, & Attia, 2004). They can also be used in formulation of Sun UV protectors that provide...