Glucosinolates and Fatty Acid, Sterol, and Tocopherol Composition of Seed Oils from Capparis spinosa Var. spinosa and Capparis ovata Desf. Var. canescens (Coss.) Heywood

Abstract

Seed oils of 11 samples of Capparis ovata and Capparis spinosa from different locations in Turkey were characterized with regard to the composition of fatty acids, tocopherols, and sterols as well as the content of glucosinolates. The oil content of the seeds ranged from 27.3 to 37.6 g/100 g (C. spinosa) and from 14.6 to 38.0 g/100 g (C. ovata). The dominating fatty acid of both species was linoleic acid, which accounted for 26.9-55.3% in C. ovata seed oils and for 24.6-50.5% in C. spinosa seed oils. Oleic acid and its isomer, vaccenic acid, were both found in the seed oils in concentrations between 10 and 30%, respectively. The seed oils of both species were rich in tocopherols with the following composition: gamma-tocopherol, 124.3-1944.9 mg/100 g; delta-tocopherol, 2.7-269.5 mg/100 g; and alpha-tocopherol, 0.6-13.8 mg/100 g. The concentration of total sterols ranged from 4875.5 to 12189.1 mg/kg (C. ovata) and from 4961.8 to 10009.1 mg/kg (C. spinosa), respectively. In addition to sitosterol, which amounted to approximately 60% of the total amount of sterols, campesterol and stigmasterol accounted for 16 and 10% of the total sterols, respectively. The seed oils showed remarkably high contents of Delta5-avenasterol (between 138.8 and 599.4 mg/kg). The total content of glucosinolates of C. ovata and C. spinosa samples was determined as 34.5-84.6 micromol/g for C. ovata and 42.6-88.9 micromol/g for C. spinosa, respectively, on a dry weight basis, with >95% as glucocapperin.