Heavy Metal Content and Antioxidant Activity of Strawberries (Fragaria vesca L.)

Abstract

Strawberry (Fragaria vesca L.) plays a valuable role in human nutrition due to its richness in minerals, vitamins, antioxidants, flavonoids, anthocyanins, and other bioactive compounds that benefit the human body. This study focused on assessing the total polyphenol content (TPC) and antioxidant activity (AA) using UV-Vis spectrophotometry, and levels of selected heavy metals (Pb and Cd) using atomic absorption spectroscopy in strawberries grown at five monitored locations in Slovakia (Hliník, Štitáre, Rišňovce, Sabinov, and Oravská Lesná). TPC values ranged from 1194 to 2389 mg GAE.kg^-1 FW, while AA values ranged from 2.89 to 3.88 mg TE.kg^-1 FW. Content of Pb ranged from 0.05–0.97 mg.kg^-1 FW, and content of Cd ranged from 0.05–0.11 mg.kg^-1 FW. The measured concentrations of Pb and Cd in strawberries were higher than the limit values set by the European Commission, except for Pb in samples from Hliník, Štitáre, and Rišňovce. Nonetheless, the strawberries from all monitored locations are safe for consumption, as the provisional maximum tolerable daily intake (PMTDI) for cadmium was not exceeded. Overall, strawberries from these locations are a good source of health-beneficial antioxidants and contain relatively low levels of hazardous metals. A negative correlation was observed between Pb levels in strawberry fruits and TPC and AA values.