Yield parameters, antioxidant activity, polyphenol and total soluble solids content of beetroot cultivars with different flesh colours

This study aimed to evaluate yield parameters, antioxidant activity (AOA), total polyphenol content (TPC) and total soluble solids (TSS) in beetroot cultivars with different flesh colours. Field experiments were established at the Slovak University of Agriculture in Nitra in 2016 and 2017. Within the study, 16 beetroot cultivars were tested, including 11 red-fleshed (‘Boltardy’, ‘Boro’ F₁, ‘Crosby Egyptian’, ‘Cylindra’, ‘Detroit Globe’, ‘Detroit 2’, ‘Egyptian Turnip Rooted’, ‘Opolski’, ‘Pablo’ F₁, ‘Renova’ and ‘Taunus’ F₁), 2 yellow-fleshed (‘Boldor’ F₁ and ‘Golden’), 2 white-flesh cultivars (‘Albino’ and ‘White Detroit’) and 1 red-white fleshed cultivar (‘Chioggia’). All beetroot cultivars with red flesh colour showed higher AOA and TPC than different-coloured beetroot cultivars. The highest root yield was found in the white-fleshed beetroot cultivar ‘Albino’ (37.80–41.91 t · ha⁻¹). The highest root weight was found in the white-fleshed beetroot cultivar ‘White Detroit’ (362.4–412.1 g). The highest AOA (819.19–972.50 mg TEAC · kg⁻¹ d.w.) and TPC (2,387.70–2,731.00 mg · kg⁻¹ d.w.) were found in the red-fleshed beetroot cultivar ‘Pablo’ F₁. Different-coloured cultivars of beetroot were characterised by a lower content of TSS (6.4–8.8 ºBRIX) than cultivars with typical, red flesh colour (7.8–10.8 ºBRIX). Results clearly indicate that cultivar, or flesh colour, is showed as a significant factor influencing the quality of beetroot. Knowing of yield potential and quality of beetroot cultivars is important for growers as well as consumers. Results of this study indicate that white-fleshed cultivars of beetroot are characterised by high yield potential but lower quality, including lower AOA, TPC and TSS.