Determination of heavy metal, phenolic compounds and antioxidant contents of turnip (Brassica rapa L.) from batman region

Turnip (Brassica rapa L.) belongs to the Cruciferae family and is one of the cultivated plants consumed since prehistoric times. Turnip is a tuberous vegetable that can be found all year round, especially widely grown in Turkey, Europe, Asia and America. In this study, changes in heavy metal, phenolic compounds and antioxidant contents were determined in 7 turnip samples collected from central and district villages of Batman region. In turnip samples, arsenic (As), cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), mercury (Hg), nickel (Ni), lead (Pb), tin (Sn), and zinc (Zn) ) levels were analyzed. The metal contents of the turnip samples were determined with an inductively coupled plasma optical emission spectrometer (ICP-OES) device after burning in the microwave unit. The heavy metal contents of these turnip samples were compared with the heavy metal values previously determined by JECFA as a standard. For example, the Iron(Fe) amount was determined as 14.32±0.045 mg/kg, and the weekly ingestible amount was determined as 0.2-25 mg/kg by JECFA. These values were calculated for all measured elements and compared with the JECFA values. In addition, phenolic compounds were measured using the LC-MS/MS device, whiwidely used in qualitative and quantitative analyses andientifically confirmed to have a very high measurement reliability. In these measurements, the phytochemical properties of turnip samples were determined and as a result of the analysis of 53 phenolic compounds, it was determined that 7 phenolic compounds were present in the turnip samples. Some of these compounds are Qunic acid, Fumaric acid, Gallic acid and Protocatechuic acid. The highest amount of qunic acid compound was detected in the turnip sample in Yayladüzü village of Gercüş district of 0.938 mg analyte/g extract, while the lowest 0.299 mg analyte/g extract was observed in the turnip sample in Boğaz village of Gercüş district. The highest amount of fumaric acid compound was found in the turnip sample of 2.998 mg analyte/g extract in Balpınar village of the central district, while the lowest 0.73 mg analyte/g extract was observed in the turnip sample in the Yayladüzü village of the Gercüş district. The highest amount of protocatechuic acid compound was detected in the turnip sample in the Balpınar village of the central district of 0.082 mg analyte/g extract, while the lowest 0.01 mg analyte/g extract was observed in the turnip sample in the Baglica village of the Gercüş district. It was determined that the amount of phenolic substance in the turnip sample in the village of Bağlıca, in the town of Gercüş, was lower than the other samples analyzed.