Red Beetroot Juice Phytochemicals Bioaccessibility: an In Vitro Approach

Abstract

Beetroot, the cultivated form of Beta vulgaris subsp. vulgaris, is known for its various bene cial properties but more critical data about its bioactive compounds digestion is needed. In the present research, the bioaccessibility of phytochemicals in freshly prepared red beetroot juice was studied. Changes in total phenolics content, total avonoids content, contents of betacyanins and betaxanthins, phenolic acids pro le as well as the antioxidant activity were monitored before and after simulated gastrointestinal digestion. Several parameters that provide interrelated information about food quality were additionally evaluated, including oxalic acid and individual sugars content, total titratable acidity, and acetylcholinesterase inhibitory activity. Signi cant loss of contents of total phenolics and avonoids measured after digestion resulted in the recovery of 27.07 and 36.4%, respectively. The same negative tendency was observed for betalains bioaccessibility. While nearly 27% of betaxanthins were present after the simulated digestion, almost all betacyanins (96.07%) have been lost. The HPLC analysis of phenolic acids of beetroot juice revealed the presence of chlorogenic, caffeic, p-coumaric, and sinapic acids. After digestion, a 2.5-fold higher concentration of chlorogenic acid was found, however caffeic and p-coumaric acids were no longer detected. The results concerning the antioxidant activity of digested juice were inexplicit. According to the DPPH assay, there was a complete recovery of antioxidant activity, while no activity was detected employing the ABTS assay. Following the cupric ion reducing antioxidant capacity (CUPRAC) and ferric-reducing antioxidant power (FRAP), approximately half of the initial activity was retained. Despite the losses, red beetroot remains a valuable source of biologically active substances. Better understanding of their transformation during digestion is further needed.

Red Beetroot. A Potential Source of Natural Additives for the Meat Industry

“…They are plant secondary metabolites with similar chemical properties, biological functions, and color spectrums as anthocyanins. However, anthocyanins and betalains never coexist together in plants [20]. Betalains are hydrophilic nitrogenous pigments, which could be subdivided into two main groups according to their chemical structure and color [26].…”

“…In the literature, there are discrepancies regarding the proportions between betacyanins and betaxanthins in beetroot, although it seems clear that the content of betacyanins in beetroot is much higher than that of betaxanthins. Some authors reported that the betacyanins represented about 80-90% of total betalains [28,29], while others found that the concentration of betacyanins was between 50-70% of total betalains [20,30]. The variation in these proportions determines the coloration of the root, and the higher content of betacyanins confers its typical red-purple pigmentation [3].…”

“…In addition to the coloring properties and in comparison with other compounds, the use of betalains as bioactive agents has not been extensively explored, despite the fact that many studies indicate that they have high antioxidant power ( Table 2). In fact, beetroot belong to the group of 10 vegetables with the highest antioxidant potential [20]. This is related to the antioxidant potential of betanin, which is about 2-fold more active than anthocyanins [26], 10-fold higher than tocopherol, and 3-fold higher than catechin [10].…”

“…), and other residues generated during processing can be considered an excellent source of raw materials that can serve as functional ingredients (antioxidants and/or colorants) [8]. The beetroot is a vegetable grown throughout the Americas, Europe, and Asia [20]. The world production in 2017 was 301 million tons, where Western Europe is the largest producer with about 70% of the total production (200 million tons) [21,22].…”

Thematic Issue on “Red Beetroot as a Source of Nutrients, Bioactive Compounds and Pigments”

“…On the other hand, the thermal stability of betalains present in by-products of red beetroot and their degradation along with raising temperature is manifested by the production of various betalain degradation products that have been determined in the work of Otálora et al ponins, being natural plant compounds exhibiting health benefi ts, in red beetroot for the fi rst time using high-speed counter-current chromatography in a new solvent system consisting of tert-butyl-methyl ether-butanol-acetonitrile-water. Aspects related to the fate of red beetroot phytochemicals after intake, such as the change in the total phenolics content, total fl avonoids content, contents of betacyanins and, betaxanthins, phenolic acids profi le as well as the antioxidant activity after simulated gastrointestinal digestion of red beetroot juice have been described by Desseva et al [2020]. Finally, the study of Płatosz et al [2020] shows the profi le of phenolic acids and fl avonoids of red beetroot and its fermentation product and explains whether the long-term consumption of fermented red beetroot juice affects phenolic compounds profi le in plasma and urine of volunteers.…”