Betacyanins and Betaxanthins in Cultivated Varieties of Beta vulgaris L. Compared to Weed Beets

Abstract

There are 11 different varieties of Beta vulgaris L. that are used in the food industry, including sugar beets, beetroots, Swiss chard, and fodder beets. The typical red coloration of their tissues is caused by the indole-derived glycosides known as betalains that were analyzed in hypocotyl extracts by UV/Vis spectrophotometry to determine the content of betacyanins (betanin) and of betaxanthins (vulgaxanthin I) as constituents of the total betalain content. Fields of beet crops use to be also infested by wild beets, hybrids related to B. vulgaris subsp. maritima or B. macrocarpa Guss., which significantly decrease the quality and quantity of sugar beet yield; additionally, these plants produce betalains at an early stage. All tested B. vulgaris varieties could be distinguished from weed beets according to betacyanins, betaxanthins or total betalain content. The highest values of betacyanins were found in beetroots ‘Monorubra’ (9.69 mg/100 mL) and ‘Libero’ (8.42 mg/100 mL). Other beet varieties contained less betacyanins: Sugar beet ‘Labonita’ 0.11 mg/100 mL; Swiss chard ‘Lucullus,’ 0.09 mg/100 mL; fodder beet ‘Monro’ 0.15 mg/100 mL. In contrast with weed beets and beetroots, these varieties have a ratio of betacyanins to betaxanthins under 1.0, but the betaxanthin content was higher in beetcrops than in wild beet and can be used as an alternative to non-red varieties. Stability tests of selected varieties showed that storage at 22 °C for 6 h, or at 7 °C for 24 h, did not significantly reduce the betalain content in the samples.

Bioactive Betalain Extracts from Cactus Pear Fruit Pulp, Beetroot Tubers, and Amaranth Leaves

“…Interestingly, Smeriglio et al [ 22 ] found the highest ORAC values (oxygen scavenging activity) in orange cactus pear fruit. It was reported by Skalicky et al [ 9 ] that the red pigment constituent showed a better correlation with antioxidant activity. Koss-Mikolajzyk et al [ 23 ] reported that the antioxidant activity of betalains decreased in the following order: orange Opuntia > red Opuntia > yellow Opuntia.…”

“…‘Betalains’ are divided into two main structural groups: the red to red-violet betacyanins (Bc) and the yellow-orange betaxanthins (Bx). With new methods and technologies, 180 different betacyanin pigments have already been described [ 9 ]. These are secondary metabolites that derive from l -tyrosine (polar aromatic amino acid) via the formation of l -dihydroxyphenylalanine ( l -DOPA).…”

Emerging technology approach for extractability and stability of betalains from the peel of beetroot (Beta vulgaris L.)

“…However, in the study of Sharma et al [39], BX was mentioned as more strongly temperature-dependent concerning BC. Skalicky and coworkers [40] claimed that the absolute stability of betalains was during storage at 22 °C for 6 h. In the study of degradation of betalains in milk, temperature elevation (10 °C) induced an approximately 1.5-fold higher reaction rate [16]. At any specific temperature, somehow, the asymptotic degradation of the color occurred after a certain time of heat treatment [19].…”

Engineering Betalain Biosynthesis in Tomato for High Level Betanin Production in Fruits

“…The beets that were used for these measures were from an unknown cultivar (purchased in a supermarket), but had the typical color of normal beetroots. It is nevertheless possible that other red beet cultivars may have higher betanin content, as betalain concentrations have been reported to vary from 97 mg of betacyanins/100 ml to 500 mg betanin/kg of fresh weight ( Lee et al, 2014 ; Skalicky et al, 2020 ). By coexpression of ADHα with the three other genes, the amount of betanin reached 2.3–2.7 g/kg of fresh weight, about 4 times the amount found in the red beet control.…”