The content of macroelements in the pulp and peel of different varieties of pear fruit

Abstract

Pear peels are usually discarded before processing of the fruits. However, it could be expected that pear peels contain more minerals. Therefore, the aim of this study was to investigate and compare the amounts of macroelements in pulp and peels of four pear cultivars ('Ksena', 'Beloruskaja Pozdniaja', 'Alna' and 'Aleksandr Lucas'). The amounts of five macroelements (nitrogen, phosphorus, calcium, magnesium and potassium) were determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The results showed that the amount of macroelements depends on pear cultivar and tissue. Pear peels have significantly higher amounts of calcium than the pulp. However, pulp contains the highest contents of nitrogen and potassium. Of the studied macroelements, potassium has the highest content in both parts of the pear fruit followed by nitrogen, phosphorus, magnesium and calcium. 'Beloruskaja Pozdniaja' and 'Ksena' peels had the highest contents of phosphorus (90.22 mg 100 g-1 and 75.12 mg 100 g-1, respectively) and magnesium (57.23 mg 100 g-1 and 66.21 mg 100 g-1, respectively). The pulp of 'Alna' and 'Aleksandr Lucas' cultivars showed the highest contents of phosphorus (87.32 mg 100 g-1 and 76.31 mg 100 g-1, respectively) and magnesium (63.12 mg 100 g-1 and 52.25 mg 100 g-1, respectively). The peel of 'Alna' had the highest amounts of calcium. Based on the present study, it can be concluded that the investigated pear peels showed only significantly higher calcium contents compared to the pulp.