Scientific journal

54 2015

Journal of Food and Nutrition Research
Summary No. 1 / 2015

Haliński, Ł. P. – Puckowski, A. – Stepnowski, P.
Glycoalkaloid, phytosterol and fatty acid content of raw and blanched leaves of the gboma eggplant (Solanum macrocarpon L.)
Journal of Food and Nutrition Research, 54, 2015, No. 1, s. 9-20

Łukasz P. Haliński, Department of Environmental Analysis, Institute for Environmental and Human Health Protection, Faculty of Chemistry, University of Gdańsk, Wita Stwosza 63, 80-308 Gdańsk, Poland. E-mail: lukasz.halinski@ug.edu.pl, tel.: (+48 58) 523 5208, fax: (+48 58) 523 5572

Received 25 January 2014; 1st revised 16 March 2014; 2nd revised 7 April 2014; accepted 12 May 2014; published online 8 December 2014.

Summary: The glycoalkaloid, sterol and fatty acid contents were determined in raw and blanched leaves of the gboma eggplant (Solanum macrocarpon L.). The results of the study revealed that 5 min blanching was sufficient to obtain a 35–56% decrease in the glycoalkaloid content in leaves to values below 200 mg·kg-1 of fresh weight, which is regarded as a safe level in foods. Processing also significantly decreased the free fatty acid content and increased the free sterol content. In raw and blanched leaves, however, the contents of total fatty acids and sterols were comparable. The total sterol content in S. macrocarpon leaves was as high as 3.2–4.0 g·kg-1 of dry weight, while the total fatty acid content was 23.0–32.1 g·kg-1 of dry weight. The cholesterol contribution to total sterols did not exceed 10%. While saturated compounds were most abundant in the free fatty acid fraction, total fatty acids were dominated by C18 polyunsaturated compounds. Additionally, isomerization of unsaturated fatty acids during hydrolysis and silylation of lipids from dried plant material was demonstrated. The presence of artefacts did not affect the results of quantitative analysis.

Keywords: Solanum macrocarpon; green leafy vegetables; glycoalkaloids; phytosterol; fatty acid; food processing

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