1171 Research Article Received: 16 May 2011 Revised: 19 August 2011 Accepted: 20 August 2011 Published online in Wiley Online Library: 23 September 2011 (wileyonlinelibrary.com) DOI 10.1002/jsfa.4659 Nutritional composition of Zizyphus lotus L. seeds Moncef Chouaibi, a,b* Nesrine Mahfoudhi, b Leila Rezig, b Francesco Dons` ı, a Giovanna Ferrari a and Salem Hamdi b Abstract BACKGROUND: Zizyphus lotus seeds are an unutilized source of vegetable oil and protein and nothing has been reported on their physicochemical characteristics which would indicate the potential uses of these seeds. RESULTS: The percentage composition of the Zizyphus lotus seeds is (on a dry-weight basis): ash 1.05%, oil 32.92%, protein 19.11%, total carbohydrate 40.87% and moisture 6.05%. Calcium, potassium and magnesium constitute the major minerals of Zizyphus lotus seeds. The seed proteins are rich in threonine, glutamic acid, leucine, arginine and aspartic acid (26.73%, 17.28%, 13.11%, 9.47% and 7.76%, respectively). The main fatty acids of the oil are oleic (61.93%), linoleic (18.31%) and palmitic (9.14%) acids. Glycerol trioleate (OOO; O: oleic acid) was the most abundant triacylglycerol, representing 26.48% of the total triacyglycerols. β -Tocopherol was the major tocopherol (130.47 mg 100 g -1 ). This oil was rich in 7-campestrol and β -sitosterol (147.82 and 82.10 mg 100 g -1 oil), respectively. CONCLUSION: Zizyphus lotus seeds are rich in fat and protein which are of potential industrial significance. In addition, Zizyphus lotus L. seed oil contained many bioactive compounds. This fact is of great economic interest owing to several applications of Zizyphus lotus L. seeds in the food, cosmetics and medicinal industries. c  2011 Society of Chemical Industry Keywords: Zizyphus lotus Mill. seeds; oil; thermal profile; fatty acid composition; chemical and physical parameters INTRODUCTION Zizyphus species (Rhamnaceae) are commonly used in folk medicine for the curing of various diseases. 1–6 They are spread widely in the Mediterranean region, growing in Tunisian arid regions and particularly in Sidi Bouzid. Zizyphus lotus, known as ‘sedra’ in Tunisia, is used as a pectoral demulcent to treat throat and bronchopulmonary irritations and for its antidiabetic properties. 7 In previous studies, it was reported that Zizyphus lotus root bark has anti-inflammatory and analgesic activities. 8,9 Its aqueous and organic extracts are characterized by the presence of flavonoids and tannins. Extracts obtained from roots, barks, leaves and fruits exhibit anti-ulcerous activity. In other previous studies, Borgi et al. 9 showed that this plant exerts anti-inflammatory activity and constitutes a potential source of analgesic drugs. A large quantity of oils and fats, whether for human consumption or for industrial purposes, is currently derived from plant sources. To meet the increasing demand for oils, improvements are being made with conventional crops as well as with selected plant species that have the ability to produce uniquely desirable oils. Interest in newer sources of edible oils has recently grown. Seed oils are important functional compounds of foods. They not only contribute to flavour, odour, colour and texture, but also confer a feeling of satiety to foods. The potential supply of lipid from fruits and fruit by-products may be enormous and should be investigated. Seeds are important oil sources for nutritional, industrial and pharmaceutical uses. So far, a large number of plants have been analysed and some of them have been cultivated as new oil crops. 10 Vegetable oils not only provide high food quality, but also contain essential nutrients for life. Seed oils are of more nutritional value if they have a more unsaturated to saturated fatty acid ratio. 11 Nothing has been reported on the physicochemical characteris- tics of Zizyphus lotus. Therefore, the objective of the present work was to evaluate chemical and physical properties of Zizyphus lotus seed oil. Knowledge gained from this study will help to determine the potential for seed oil from these Zizyphus lotus fruits to be com- mercially exploited for industrial applications and incorporation into food formulations to improve human health. MATERIALS AND METHODS Materials Zizyphus lotus fruits are fleshy glabrous drupes 1–3cm in diameter. When immature, they are green, but when they become ∗ Correspondence to: Moncef Chouaibi, Department of Chemical and Food Engineering, University of Salerno, Via Ponte Don Melillo, 84084 (SA), Italy. E-mail: moncef.chouaibi@yahoo.com.au a Department of Chemical and Food Engineering, University of Salerno, Salerno 84084, Italy b Food Preservation Laboratory, High Institute of Food Industry, Elkhadra City, Tunis 1003, Tunisia J Sci Food Agric 2012; 92: 1171–1177 www.soci.org c  2011 Society of Chemical Industry