Development of a new analytical method for the determination of red beetroot betalains using dispersive solid-phase extraction

Betalains and their applications in food: The current state of processing, stability and future opportunities in the industry

Betalains are water-soluble nitrogenous pigments with coloring properties and antioxidant activities, which is why they have been incorporated into several foods. However, their use is limited by their instability in response to different factors, such as, pH, oxygen, water activity, light, metals, among others. In this work, a review of up-to-date and relevant information is presented on the primary natural sources of betalains. Additionally, the advantages and disadvantages of the primary betalain extraction techniques are discussed and compared. The results of these studies were focused on the stability of betalains when incorporated into foods, either in pure or encapsulated form, and they are discussed through different technologies. Lastly, the most relevant information related to their stability and a projection of their promising future applications within the food industry is presented.

Identification of New Betalains in Separated Betacyanin and Betaxanthin Fractions from Ulluco (Ullucus tuberosus Caldas) by HPLC-DAD-ESI-MS

An improved methodology of achieving an accurate separation of pure fractions of betacyanins and betaxanthins from Ullucus tuberosus Caldas has been carried out. For that purpose, an in-depth chemical identification of each betalain fraction using HPLC-DAD-ESI-MS was developed. This procedure allowed to evaluate the fractionation efficiency and also identify a large number of betalains, most of which have not been described so far in this raw material: betanidin- and isobetanidin-5-O-(4'-O-malonyl-β-glucoside), 2-decarboxy-phyllocactin, betanidin- and isobetanidin-6-O-(6'-O-feruloyl)-β-glucoside (gomphrenin and isogomphrenin III), dehydro-phyllocactin and isophyllocactin, and arginine and glycine-betaxanthins (portulacaxanthin III). Moreover, the availability of pure betalain fractions by the proposed methodology permitted to establish the total betalain content and the antioxidant activity of both separated betacyanin and betaxanthin fractions of ulluco for the first time. The results suggest Ullucus tuberosus as an underutilized food bioactive source with a high concentration of total betaxanthins (21.8 μg indicaxanthin/g fresh ulluco) and betacyanins (44.5 μg betanin/g fresh ulluco), strongly correlated to the Folin-Ciocalteau reduction capacity.

Opuntia ficus-indica (L.) Mill. fruit as source of betalains with antioxidant, cytoprotective, and anti-angiogenic properties

The aim of this work was to investigate the phytochemical profile and biological properties of different colours of betalain cactus pear extracts, evaluating their antioxidant, cytoprotective, and anti-angiogenic properties by cell-free, cell-based, and in vivo assays. A QuEChERS extraction method followed by RP-LC-DAD-MS/MS analysis showed that indicaxanthin and betanin were the main compounds (≥94.32% and ≥96.95%, respectively). Orange cactus pear extracts exert the best antioxidant activity in all assays carried out, in particular into ORAC (17,352.55 ± 987.407 mg trolox equivalents/100 g dry weight) and β-carotene bleaching (60.35%) assays. The red ones, instead, showed the best cytoprotective activity decreasing the cell mortality, LDH, and Caspase-3 release ranging from 4.0 to 55%. According to antioxidant results, the orange cactus pear extracts showing also the highest anti-angiogenic activity (IC₅₀ 19.31 μg/ml), followed by the red (IC₅₀ 23.55 μg/ml) and the yellow ones (IC₅₀ 33.97 μg/ml). In light of the results and correlation analysis, the behaviour of these molecules varies a lot according to their structure and physicochemical features and synergistic activity between betalain classes may be postulated; so the plant complex could be of greater interest compared with the isolated molecules for potential nutraceutical and pharmaceutical uses.

Conical intersections and the weak fluorescence of betalains

Betalains are natural plant pigments found in certain plants belonging to the order Caryophyllales.