Phenolic Compounds, Tocopherols, Carotenoids and Vitamin C of Commercial Caper

The contents of antioxidant compounds were examined in four commercial samples of caper, which is one of the most commonly found aromatics in the Mediterranean kitchen. Analyses were performed by using the colorimetric assay (total phenolic compounds and vitamin C) and high-performance liquid chromatography (rutin, carotenoids and tocopherols). Moreover, vitamin A activity (as retinol equivalents) was calculated. Phenolic compound contents ranged from 1151.6 ± 19.8 to 2243.96 ± 48.2 mg/100 g FW, while rutin contents ranged from 150.62 ± 5.18 to 732.61 ± 10.49 mg/100 g FW. Total tocopherol content was from 700.23 ± 10.49 to 2555.41 ± 71.12 µg/100 FW, with α-tocopherol as the predominant isomer in all samples. β-carotene ranged between 84.8 ± 9.5 and 805.71 ± 17.73 µg/100 g FW. Capers also contained an appreciable amount of vitamin C. These results bring attention to the antioxidant vitamin value and nutritional importance of commercial caper. PRACTICAL APPLICATIONS Results show that caper contain significant amounts of antioxidants (total phenolic compounds, rutin, tocopherols, carotenoids; and appreciable levels of vitamin C) as bioactive compounds. Irrespective of the variation between countries, commercial caper contained important contents of these compounds, thus showing caper has a great interest for its nutritional value. The combined contents of these antioxidants in commercial capers encourage consumers to increase their intake. Also, these results should be useful for researchers to explore and develop further this plant and its storage conditions for human consumption and medicinal uses.