Identification and quantification of betalains from the fruits of 10 mexican prickly pear cultivars by high-performance liquid chromatography and electrospray ionization mass spectrometry

Atriplex hortensis var. 'rubra' extracts and purified amaranthin-type pigments reduce oxidative stress and inflammatory response in LPS-stimulated RAW264.7 cells

The use of direct injection ion mobility mass spectrometry (DI-IM-MS) to detect and identify betacyanin pigments in A. hortensis 'rubra' extracts was explored for the first time, with results compared to conventional LC-MS/MS analysis. The anti-inflammatory activities of leaf and seed extracts, alongside purified amaranthin and celosianin pigments, were investigated using a model of lipopolysaccharide (LPS)-activated murine macrophages. Extracts and purified pigments significantly inhibited the production of prostaglandin E2 and NO by up to 90% and 70%, respectively, and reduced the expression of Il6, Il1b, Nos2, and Cox2. Leaf and seed extracts also decreased secretion of Il6 and Il1b cytokines and reduced protein levels of Nos2 and Cox2. Furthermore, extracts and purified pigments demonstrated potent dose-dependent radical scavenging activity in a cellular antioxidant activity assay (CAA) without any cytotoxic effects. Our research highlights the promising biological potential of edible, climate-resilient A. hortensis 'rubra' as a valuable source of bioactive compounds.

A simple and efficient method for betalain quantification in RUBY-expressing plant samples

The RUBY reporter system has demonstrated great potential as a visible marker to monitor gene expression in both transiently and stably transformed plant tissues. Ectopic expression of the RUBY reporter leads to bright red pigmentation in plant tissues that do not naturally accumulate betalain. Unlike traditional visual markers such as β-glucuronidase (GUS), luciferase (LUC), and various fluorescent proteins, the RUBY reporter system does not require sample sacrifice or special equipment for visualizing the gene expression. However, a robust quantitative analysis method for betalain content has been lacking, limiting accurate comparative analyses. In this work, we present a simple and rapid protocol for quantitative evaluation of RUBY expression in transgenic plant tissues. Using this method, we demonstrate that differential RUBY expression can be quantified in transiently transformed leaf tissues, such as agroinfiltrated Nicotiana benthamiana leaves, and in stable transgenic maize tissues, including seeds, leaves, and roots. We found that grinding fresh tissues with a hand grinder and plastic pestle, without the use of liquid nitrogen, is an effective method for rapid betalain extraction. Betalain contents estimated by spectrophotometric and High-Performance Liquid Chromatography (HPLC) analyses were highly consistent, validating that our rapid betalain extraction and quantification method is suitable for comparative analysis. In addition, betalain content was strongly correlated with RUBY expression level in agroinfiltrated N. benthamiana leaves, suggesting that our method can be useful for monitoring transient transformation efficiency in plants. Using our rapid protocol, we quantified varying levels of betalain pigment in N. benthamiana leaves, ranging from 110 to 1066 mg/kg of tissue, and in maize samples, ranging from 15.3 to 1028.7 mg/kg of tissue. This method is expected to streamline comparative studies in plants, providing valuable insights into the effectiveness of various promoters, enhancers, or other regulatory elements used in transgenic constructs.

Microencapsulation of Betalains Extracted from Garambullo (Myrtillocactus geometrizans) to Produce Active Chitosan-Polyvinyl Alcohol Films with Delayed Release of Bioactive Compounds

Garambullo is a plant with little industrial application. However, garambullo contains betalains, photosensitive phytochemical compounds, which through microencapsulation can be used in chitosan-polyvinyl alcohol (PVOH) films for application in tomato coatings. These biopackages were characterized by physical tests, water vapor permeability, puncture tests, extension, color, differential scanning calorimetry (DCS), Fourier transform infrared (FTIR) spectroscopy, and antioxidant and antimicrobial activity analyses. The influence of the biopackages on the tomato coatings was measured using parameters such as minimum weight loss close to 2% at day 9, pH of 4.6, Brix of 5.5, titratable acidity of 1 g acid/100 mL sample, and shelf life of up to 18 days. The biopackages containing betalain microcapsules had a water vapor permeability of 2 × 10-14 g/h·m·Pa and an elongation of 5 ± 0.5%, indicating that the package did not stretch. The deformation at the breaking point for the package without and with microcapsules was 0.569 and 1.620, respectively. With respect to color, adding white microcapsules and betalains can cause the material to darken, resulting in a yellowish color. Furthermore, the phenolic content was greater for the biopackages with betalains, while there was no significant difference in the antioxidant activity since the active compounds were not released. According to the in vitro results, the inhibition of B. cinerea was achieved on the eighth day when the active compounds were released from the microcapsules. The tomato with betalains lost 2% of its weight, and B. cinerea was inhibited, extending its shelf life to 18 days. The proposed biopackages have good properties as biopolymers and inhibit the presence of B. cinerea.

HPLC-Based Metabolomic Analysis and Characterization of Amaranthus cruentus Leaf and Inflorescence Extracts for Their Antidiabetic and Antihypertensive Potential

The aim of this study was to investigate the potential of Amaranthus cruentus flavonoids (quercetin, kaempferol, catechin, hesperetin, naringenin, hesperidin, and naringin), cinnamic acid derivatives (p-coumaric acid, ferulic acid, and caffeic acid), and benzoic acids (vanillic acid and 4-hydroxybenzoic acid) as antioxidants, antidiabetic, and antihypertensive agents. An analytical method for simultaneous quantification of flavonoids, cinnamic acid derivatives, and benzoic acids for metabolomic analysis of leaves and inflorescences from A. cruentus was developed with HPLC-UV-DAD. Evaluation of linearity, limit of detection, limit of quantitation, precision, and recovery was used to validate the analytical method developed. Maximum total flavonoids contents (5.2 mg/g of lyophilized material) and cinnamic acid derivatives contents (0.6 mg/g of lyophilized material) were found in leaves. Using UV-Vis spectrophotometry, the maximum total betacyanin contents (74.4 mg/g of lyophilized material) and betaxanthin contents (31 mg/g of lyophilized material) were found in inflorescences. The leaf extract showed the highest activity in removing DPPH radicals. In vitro antidiabetic activity of extracts was performed with pancreatic α-glucosidase and intestinal α-amylase, and compared to acarbose. Both extracts exhibited a reduction in enzyme activity from 57 to 74%. Furthermore, the in vivo tests on normoglycemic murine models showed improved glucose homeostasis after sucrose load, which was significantly different from the control. In vitro antihypertensive activity of extracts was performed with angiotensin-converting enzyme and contrasted to captopril; both extracts exhibited a reduction of enzyme activity from 53 to 58%. The leaf extract induced a 45% relaxation in an ex vivo aorta model. In the molecular docking analysis, isoamaranthin and isogomphrenin-I showed predictive binding affinity for α-glucosidases (human maltase-glucoamylase and human sucrase-isomaltase), while catechin displayed binding affinity for human angiotensin-converting enzyme. The data from this study highlights the potential of A. cruentus as a functional food.

Bioactive compounds and antioxidant activity in garambullo fruit (Myrtillocactus geometrizans) at different ripening stages

Garambullo (Myrtillocactus geometrizans) is endemic in México, and although popularly consumed locally, its nutritional characteristics and value have not been studied in details. The objective of this work was to investigate the bioactive compounds and antioxidant activity in garambullo fruit from different sites at three ripening stages. Fruit from the three ripening stages (red, purple, and dark purple) were investigated for their physicochemical characteristics, hydrophilic (phenolic compounds, betalains, and ascorbic acid), and lipophilic (carotenoids, tocopherols, and fatty acids) bioactive compounds, using spectrophotometry, gas chromatography (GC-FID), and high-pressure liquid chromatography coupled to mass spectrometry (HPLC/DAD-ESI-MS). The antioxidant capacity was measured with the 2,2'-diphenyl-1-picrylhydrazyl and the ferric-ion-reducing antioxidant power assays. The color components of the fruit, chroma and a* values increased, whereas lightness (L*) and b* significantly decreased during ripening. Five betacyanins and four betaxanthins were tentatively identified with HPLC/DAD-ESI-MS, and betacyanins were more abundant than betaxanthins. Betalains content and antioxidant capacity of hydrophilic extracts significantly increased during ripening. Ten phenolic compounds were identified, with ferulic acid being the most abundant. Tocopherols were low (0.023-0.033 mg/100 g fw). Five fatty acids were abundant, and linoleic acid was the most important. Phenolic compounds, ascorbic acid, total carotenoids, and fatty acids decreased during fruit ripening. Garambullo fruit is rich in phytochemical compounds of importance for human nutrition and health. PRACTICAL APPLICATION: The physicochemical and bioactive compounds characterization in garambullo fruit is important to establish maturation and harvesting indices, postharvest strategies to preserve fruit quality and prolong postharvest life, promote the consumption and utilization of the fruit, and the designing of proper functional foods. In addition, the knowledge on the bioactive components might be useful to include this fruit in personalized nutritional approaches for patients with risks of certain chronic diseases. The methodology used in this study could be useful for the study of other fruits, especially those from the Cactaceae family.

The In Vitro Simulated Gastrointestinal Digestion Affects the Bioaccessibility and Bioactivity of Beta vulgaris Constituents

Beetroot (Beta vulgaris L.) is an important root vegetable crop and a valuable food source of micronutrients and bioactive constituents. In this study, the bioaccessibility of minerals, organic acids, and betacyanins in beetroot powder during simulated gastrointestinal digestion was investigated, as well as the antioxidant activity of the final fractions of each phase of the process. Mineral elements were analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES), organic acids by ultra-fast liquid chromatography with photodiode array detection (UFLC-PDA), and betacyanins by liquid chromatography with diode-array detection and mass spectrometry (HPLC-DAD-ESI/MSn). The oxidative hemolysis inhibition assay was used to assess the ex vivo antioxidant activity. The bioaccessibility of minerals at the end of gastrointestinal digestion ranged from 43 to 65%, depending on the mineral element. Among these, Mg was the most bioaccessible, while Ca and Fe had the lowest bioaccessibility. For organic acids, a major release during digestion was observed for quinic acid. It was also found that betanin (the major betalain in beetroot) was highly unstable during the digestion process, probably due to its hydrophilic nature, which agreed with the significant (p < 0.05) decrease in antioxidant/antihemolytic activity. These results suggest that beetroot antioxidant compounds are unstable under gastrointestinal conditions, and could be useful for future development of novel and more stable beetroot food formulations.

Molecular and Antioxidant Characterization of Opuntia robusta Fruit Extract and Its Protective Effect against Diclofenac-Induced Acute Liver Injury in an In Vivo Rat Model

A molecular characterization of the main phytochemicals and antioxidant activity of Opuntia robusta (OR) fruit extract was carried out, as well as an evaluation of its hepatoprotective effect against diclofenac (DF)-induced acute liver injury was evaluated. Phenols, flavonoids and betalains were quantified, and antioxidant characterization was performed by means of the ABTS^•+, DPPH and FRAP assays. UPLC-QTOF-MS/MS was used to identify the main biocompounds present in OR fruit extract was carried out via. In the in vivo model, groups of rats were treated prophylactically with the OR fruit extract, betanin and N-acteylcysteine followed by a single dose of DF. Biochemical markers of oxidative stress (MDA and GSH) and relative gene expression of the inducible antioxidant response (Nrf2, Sod2, Hmox1, Nqo1 and Gclc), cell death (Casp3) and DNA repair (Gadd45a) were analyzed. Western blot analysis was performed to measure protein levels of Nrf2 and immunohistochemical analysis was used to assess caspase-3 activity in the experimental groups. In our study, the OR fruit extract showed strong antioxidant and cytoprotective capacity due to the presence of bioactive compounds, such as betalain and phenols. We conclude that OR fruit extract or selected components can be used clinically to support patients with acute liver injury.

Chemical characterization of yellow-orange and purple varieties of Opuntia ficus-indica fruits and thermal stability of their betalains

Betalains are plant pigments with biological properties and can be used instead of synthetic colorants to confer color and functional properties to foods. The objective of this work was to carry out the chemical characterization of two varieties of prickly pear of Opuntia ficus-indica, one of yellow-orange coloration (Mandarina) and the other of purple coloration (Vigor), through measurements of chemical parameters and color in pulp, antioxidant activity, total phenolic compounds, and betalain content. Considering the thermolability of betalains and their potential applications in food, the thermal stability and activation energy of betacyanins from Vigor variety and betaxanthins from the Mandarina variety were also evaluated and compared with those from beetroot, the main source of betalains. Results for chemical characterization agreed with previous prickly pear reports of other regions, while the thermal degradation kinetics of betalains showed a first-order degradation pattern with respect to time and temperature treatment. Betacyanins from Vigor prickly pear showed similar thermal stability to those from beetroot, which was reflected in similar values of activation energy, while betaxanthins from Mandarina prickly pear showed a higher stability, and therefore a higher activation energy, than those from beetroot. Based on the results, the prickly pear varieties used in this study can be considered as a good source of betalains with potential applications in food and, in addition, the methodology for the evaluation of thermostability can be used to compare the stability of betalains from different sources in a temperature range of 50-90°C. PRACTICAL APPLICATION: The varieties of prickly pear used in this study can be considered a good source of red-purple and yellow-orange easily extractable pigments. In addition, we report a methodology that can be used for the evaluation of the thermal stability of these pigments and to compare this stability between different plant sources. Gaining knowledge on betalain thermal stability will make it possible to propose specific applications, for example, in processed foods requiring different pigment stabilities.

An overview and update on the chemical composition and potential health benefits of Opuntia ficus-indica (L.) Miller

Opuntia ficus-indica (OFI), widely recognized as prickly pear, is native to Mexico and it is distributed in many areas of the world because of its socioeconomic, agronomic, and ecological benefits, besides its large amounts of functional, nutraceutical, and biological activities. Various parts of this plant including the fruit pulp and peel, cladode, and seeds are scientifically proven to have therapeutic potentials and are safe for human use. The contents of phytochemical compounds in each part of the OFI are different. Each pharmacological activity depends on the phytochemical compounds, the components used, and the extraction type. In this review, we summarize the active constituents from different parts of OFI and their pharmacological effects including the antioxidant, wound healing, skin protective, hepatoprotective, anticancer, antidiabetic, antihypercholesterolemic, and anti-obesity activities. Besides its effects on the bone health, cardiovascular system, kidneys, and gastrointestinal tract, its gastroprotective, anti-ulcer, anti-inflammatory, antiviral, neuroprotective, sedative, analgesic, anxiolytic and antimicrobial effects and effects on cognitive and memory function are also mentioned. PRACTICAL APPLICATIONS: Over the past few decades, the health benefits of Opuntia ficus-indica (OFI) have received much attention. All parts of the plant, including the fruit pulp and peel, cladode, and seeds have found use in the treatment of many diseases. The chemical composition of OFI provides both a high nutritional value and various health benefits. Therefore, the aim of this review is to present the up-to-date research carried out on OFI phytochemicals, showing the most important biological activities reported.

Hepatoprotective Effect of Opuntia robusta Fruit Biocomponents in a Rat Model of Thioacetamide-Induced Liver Fibrosis

Liver fibrosis is a chronic disease associated with oxidative stress that has a great impact on the population mortality. Due to their antioxidant capacity, we evaluated the protective effect of Opuntia robusta fruit (Or) on liver fibrosis. A nutraceutical characterization of Or was performed and a model of fibrosis was induced with thioacetamide (TAA) in Wistar rats. Aminotransferases, reduced glutathione (GSH) and histopathology were evaluated. Or contained 436.5 ± 57 mg of Betacyanins equivalents/L., 793 mg of catechin equivalents (CAE)/100 g for flavonoids, 1118 mg of gallic acid equivalents (GAE)/100 g for total phenols, 141.14 mg/100 g for vitamin C and 429.9 μg/100 g for vitamin E. The antioxidant capacity of Or was: 2.27 mmol of Trolox® equivalents (TE)/L (DPPH), 62.2 ± 5.0 μmol TE/g (ABTS•+), 80.2 ± 11.7 μmol TE/g (FRAP), 247.9 ± 15.6 µmol TE/g (AAPH) and 15.0% of H2O2 elimination. An increase (p < 0.05) of aminotransferases and a decrease (p < 0.05) of hepatic GSH was observed in the TAA group compared to the control and the concomitant groups. Histopathology showed changes in the normal architecture of the liver treated with TAA compared to the concomitant treatments. Or contains bioactive components with antioxidant capacity, which can reduce fibrotic liver damage.

Betalain-rich dragon fruit (pitaya) consumption improves vascular function in men and women: a double-blind, randomized controlled crossover trial

BACKGROUND

Betalains are natural red color pigments abundant in red-fleshed dragon fruit (Hylocereus polyrhizus). Recent research has shown that dragon fruit consumption may help improve blood glucose and lipid profile. However, investigations of its cardioprotective properties in human trials, especially in nutritionally achievable amounts, remain nonexistent.

OBJECTIVES

The aim of this study was to investigate the effects of acute and short-term consumption of dragon fruit on vascular function in a healthy population.

METHODS

A randomized, double-blind, placebo-controlled, crossover trial was conducted in 19 young, healthy, nonsmoking men and women assigned to consume 24 g whole dragon fruit powder (33 mg betalains) or a nutrient-matched placebo, daily for 14 d. Flow-mediated dilation (FMD), arterial stiffness, and blood pressure (BP) were measured at 0 h, 1 h, 2 h, 3 h, and 4 h and finally at 14 d after daily consumption.

RESULTS

A total of 18 participants completed the trial. Dragon fruit consumption significantly improved acute FMD at 2 h (+0.8 ± 0.3%, P = 0.01), 3 h (+1.0 ± 0.3%, P = 0.001), and 4 h (+1.3 ± 0.4%, P < 0.001) postconsumption compared with placebo. This effect was sustained up until 14 d (+1.3 ± 0.2%, P < 0.001). Pulse-wave velocity was acutely significantly reduced at 3 h (-0.5 ± 0.2 m/s, P = 0.003), whereas augmentation index (AIx) also improved after 14 d (-7.0 ± 3.3%, P = 0.02) when compared with placebo. No differences were found in either peripheral or central BP across all time points.

CONCLUSIONS

Acute and short-term consumption of dragon fruit in dietary achievable amounts improved endothelial function and arterial stiffness in healthy individuals. This implies that regular dragon fruit consumption may have a meaningful impact on cardiovascular disease risk likely due to the high betalain content. This trial was registered at ClinicalTrials.gov as NCT03995602.

Physical, Chemical and Microbiological Properties during Storage of Red Prickly Pear Juice Processed by a Continuous Flow UV-C System

The effects of pH (3.6 and 7.0) and irradiation UV-C dose irradiation (0, 9.81, 15.13, and 31.87 mJ/cm2) on the physicochemical properties and natural microbiota of red prickly pear juice were evaluated during processing and storage. Thermal treatments were used as the control applying high temperatures for a short time (HTST 80 °C/30 s) or ultra-high temperature (UHT 130 °C/3 s). UV-C treatments applied to juices with both pHs inactivated coliforms and mesophiles with the same efficacy as thermal treatments. Yeasts and molds were inactivated at a dose of >15.13 mJ/cm2 at both pHs. The UV-C doses showed no differences in betalains, polyphenols, or antioxidant activity. However, a decrease in these compounds was observed during storage. The lowest reductions in betacyanins (11.1–16.7%) and betaxanthins (2.38–10.22%) were obtained by UV-C treatment at pH 3.6. Thermal treatments (HTST and UHT) caused a reduction greater than UV-C irradiation in betacyanins, betaxanthins, polyphenols, and antioxidant activity after treatment. However, after storage at pH 3.6, the contents of these compounds reached those of the UV-C treatments, except for polyphenols. In specific pigments, betanin retention was highest at pH 3.6 (62.26–87.24%), and its retention decreases with UV-C dose increase and storage. The indicaxanthin retentions were higher (75.85–92.27%) than those of betanin, and the reduction was mainly due to storage. The physical properties (pH, acidity, and °Brix) were not affected by treatments, except for the color. The results suggest that a dose of 15.13 mJ/cm2 of a continuous UV-C system is a non-thermal alternative for the processing of red prickly pear juice at pH 3.6, preserving its properties.

Comprehensive Betalain Profiling of Djulis (Chenopodium formosanum) Cultivars Using HPLC-Q-Orbitrap High-Resolution Mass Spectrometry

Betalains are water-soluble pigments that may be used as alternatives to artificial colorants in the food industry. In addition, the betalain profile may be of taxonomic significance to some higher plants. Djulis (Chenopodium formosanum) is an emerging crop grown by Taiwan aboriginal communities, and its various cultivars contain different betalain compositions. To develop an authenticity method for evaluating djulis cultivars, we performed comprehensive betalain profiling with HPLC-Q-Orbitrap high-resolution mass spectrometry (HRMS). An HRMS method for betalain annotation was developed and used to identify 68 betalains, including 10 betacyanins, 24 betacyanin derivatives, and 34 betaxanthins. The profile of betacyanins and their derivatives could be utilized to classify different cultivars of djulis, while betaxanthins were less informative. Furthermore, the betalain profiles were indicative of the geographic origin of djulis. This HRMS method and analytical platform for betalains may be helpful to guide further investigations of natural pigments in other plants.

Betalains in Edible Fruits of Three Cactaceae Taxa-Epiphyllum, Hylocereus, and Opuntia-Their LC-MS/MS and FTIR Identification and Biological Activities Evaluation

Epiphyllum, Hylocereus, and Opuntia plants belong to the Cactaceae family. They are mostly known as ornamental plants but also for their edible fruits, which can potentially be sources of betalains, such as betanin, a natural pigment used in the food industry, e.g., under the European label code E 162. The aim of this work was the identification of betalains (using LC-MS/MS), evaluation of total betalain content (spectrophotometrically), analysis of functional groups (using FT-IR), evaluation of antioxidant activity (using DPPH, ABTS, FRAP, DCFH-DA, and reducing power methods) and evaluation of antimicrobial activity (S. aureus, E. coli, and C. albicans) in fruits of Epiphyllum, Hylocereus, and Opuntia taxa. A total of 20 betalains were identified in the studied Cactaceae fruits. The Epiphyllum pink hybrid had the highest values of total betalains amongst all samples. The highest antioxidant activity was observed in the Epiphyllum pink hybrid, in Opuntia zacuapanensis and O. humifusa fruits. The antimicrobial activity assay showed that cacti fruits were not able to effectively inhibit the growth of E. coli, S. aureus, or C. albicans. Our results prove that these fruits are good sources of natural pigments-betalains. They do not contain toxic compounds in significant amounts and they exhibit antioxidant activity.

Multi-colored shades of betalains: recent advances in betacyanin chemistry

Covering: 2001 to 2021Betacyanins cover a class of remarkable natural red-violet plant pigments with prospective chemical and biological properties for wide-ranging applications in food, pharmaceuticals, and the cosmetic industry. Betacyanins, forming the betalain pigment group together with yellow betaxanthins, have gained much attention due to the increasing social awareness of the positive impact of natural products on human health. Betalains are commercially recognized as natural food colorants with preliminarily ascertained, but to be further investigated, health-promoting properties. In addition, they exhibit a remarkable structural diversity based on glycosylated and acylated varieties. The main research directions for natural plant pigments are focused on their structure elucidation, methods of their separation and analysis, biological activities, bioavailability, factors affecting their stability, industrial applications as a plant-based food, natural colorants, drugs, and cosmetics as well as methods for high-yield production and stabilization. This review covers period of the last two decades of betacyanin research. In the first part of the review, we present an updated classification of all known betacyanins and their derivatives identified by chemical means as well as by mass spectrometric and NMR techniques. In the second part, we review the current research reports focused on the chemical properties of the pigments (decarboxylation, oxidation, conjugation, and chlorination reactions as well as the acyl group migration phenomenon) and describe the semi-synthesis of natural and artificial fluorescent betalamic acid conjugates, showing various prospective research directions.

Bioaccessibility of Antioxidants in Prickly Pear Fruits Treated with High Hydrostatic Pressure: An Application for Healthier Foods

High hydrostatic pressure (HHP) is a commercial processing technology which can enhance the health potential of foods by improving the bioaccessibility of their bioactive compounds. Our aim was to study the bioaccessibility and digestive stability of phenolic compounds and betalains in prickly pear fruits (Opuntia ficus-indica L. Mill. var. Pelota and Sanguinos) treated with HHP (100, 350, and 600 MPa; come-up time and 5 min). The effects of HHP on pulps (edible fraction) and peels (sources of potential healthy ingredients) were assessed. In pulps, betanin bioaccessibility increased (+47% to +64%) when treated at 350 MPa/5 min. In HHP-treated pulps, increases in the bioaccessibility of piscidic acid (+67% to +176%) and 4-hydroxybenzoic acid glycoside (+126% to 136%) were also observed. Isorhamnetin glycosides in peels treated at 600 MPa/CUT had higher bioaccessibility (+17% to +126%) than their controls. The effects of HHP on the bioaccessibility of health-promoting compounds are not exclusively governed by extractability increases of antioxidants in the food matrix (direct effects). In this work we found evidence that indirect effects (effects on the food matrix) could also play a role in the increased bioaccessibility of antioxidants in fruits treated with HHP.

Characterization, Stability, and Bioaccessibility of Betalain and Phenolic Compounds from Opuntia stricta var. Dillenii Fruits and Products of Their Industrialization

The aim of the present study was the full characterization, quantification, and determination of the digestive stability and bioaccessibility of individual betalain and phenolic compounds of Opuntia stricta, var. Dillenii fresh fruits (peel, pulp, and whole fruit) and of the products of the industrialization to obtain jam (raw pressed juice (product used for jam formulation), by-product (bagasse), and frozen whole fruit (starting material for jam production)). Opuntia stricta var. Dillenii fruits and products profile showed 60 betalain and phenolic compounds that were identified and quantified by HPLC-DAD-ESI/MS and HPLC-DAD-MS/QTOF, being 25 phenolic acids (including isomers and derivatives), 12 flavonoids (including glycosides), 3 ellagic acids (including glycosides and derivative), and 20 betanins (including degradation compounds). In vitro gastrointestinal digestion was performed by INFOGEST^® protocol. Fruit pulp showed the greater content of total betalains (444.77 mg/100 g f.w.), and jam only showed very low amounts of two betanin degradation compounds, Cyclo-dopa-5-O-β-glucoside (and its isomer) (0.63 mg/100 f.w.), and two Phyllocactin derivatives (1.04 mg/100 g f.w.). Meanwhile, fruit peel was the richer tissue in total phenolic acids (273.42 mg/100 g f.w.), mainly in piscidic acid content and total flavonoids (7.39 mg/100 g f.w.), isorhamnetin glucoxyl-rhamnosyl-pentoside (IG2) being the most abundant of these compounds. The stability of betalains and phenolic compounds during in vitro gastrointestinal digestion is reported in the present study. In Opuntia stricta var. Dillenii pulp (the edible fraction of the fresh fruit), the betanin bioaccessibility was only 22.9%, and the flavonoid bioaccessibility ranged from 53.7% to 30.6%, depending on the compound. In non-edible samples, such as peel sample (PE), the betanin bioaccessibility was 42.5% and the greater bioaccessibility in flavonoids was observed for quercetin glycoside (QG1) 53.7%, the fruit peel being the most interesting material to obtain antioxidant extracts, attending to its composition on antioxidant compounds and their bioaccessibilities.

Development of active and smart packaging films based on starch, polyvinyl alcohol and betacyanins from different plant sources

In this study, active and smart packaging films were prepared by individually adding betacyanins-rich plant extracts (red pitaya flesh extract (RPFE), prickly pear fruit extract (PPFE), red beetroot extract (RBRE), globe amaranth flower extract (GAFE) and red amaranth leaf extract (RALE)) into starch/polyvinyl alcohol. The structural, physical and functional properties of the films containing betacyanins from different plant sources were compared for the first time. Results showed betacyanins from RPFE, PPFE and RBRE were betanin-type betacyanins. Betacyanins from GAFE and RALE were gomphrenin-type and amaranthin-type betacyanins, respectively. The films containing RPFE and PPFE presented more uniform cross-sections and had the highest water vapor barrier (9.37 and 9.26 × 10^-11 g m^-1 s^-1 Pa^-1) and mechanical strength (8.26 and 7.87 MPa). However, the film containing GAFE presented the lowest light transmittance but the highest 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (EC₅₀ = 0.47 mg/mL). All the films containing betacyanins are sensitive to pH 8-12 buffer solutions and volatile ammonia. Notably, the film containing RPFE exhibited distinct color changes (from purple-red to pink) when shrimp spoiled. Our results suggest the structural, physical and functional properties of betacyanins-rich films are closely related to the source and type of betacyanins.

Evaluating the effect of additives on stability of betacyanin pigments from Basella rubra in a model beverage system during storage

The effect of selected additives (catechin, ascorbic acid, β-cyclodextrin and EDTA) on the stability of betacyanin pigments from Basella rubra in a model beverage system was investigated and they exhibited remarkable outcomes. The major betacyanin pigment in B. rubra extract was identified to be gomphrenin-I using HPLC-ESI-MS analysis method. The degradation kinetics of betacyanin pigment in the model beverage variants was established, and temperature was found to be the most detrimental factor. If effect of additives on stability of B. rubra betacyanin pigments in model beverage stored at 4 °C in the absence of light and oxygen is considered, maximum stabilizing effect was demonstrated by catechin (t_1/2 203.9 days) followed by EDTA (t_1/2 187.3 days) and then β-cyclodextrin (t_1/2 144.4 days) when compared with control (t_1/2 119.5 days) whereas, ascorbic acid acted as a prooxidant and reduced storage stability of the pigment (t_1/2 78.8 days).

Sensory attributes, physicochemical and antioxidant characteristics, and protein profile of wild prickly pear fruits (O. macrocentra Engelm., O. phaeacantha Engelm., and O. engelmannii Salm-Dyck ex Engelmann.) and commercial prickly pear fruits (O. ficus-indica (L.) Mill.)

Mexico presents the highest richness of Opuntia Mill. species. These species are an important economic factor for the country, and source of nutrients, bioactive compounds, pigments, and nutraceuticals which can be of interest for the food and pharmaceutical industry. However, there are some wild Opuntia species in the Chihuahua desert, that have not been analyzed to establish their properties and potential use. The aim of study was to evaluate the sensory, physicochemical and protein profile in wild prickly pear fruits (O. macrocentra Engelm. (OM), O. phaeacantha Engelm. (OP), and O. engelmannii Salm-Dyck ex Engelmann. (OE)) from Samalayuca, Chihuahua and compare them with two commercial prickly pear fruits (O. ficus-indica (L.) Mill. (green-OFG, red-OFR). The sensory profile of wild species was characterized by highest color, odor, and sour taste compared to the commercial fruits. Pulp, peel, and seeds from wild prickly pear fruits showed lower pH, and higher titratable total acidity, total phenolic compounds, total flavonoids, antioxidant capacity, protein, lipids, ash, carbohydrates (only peel), and crude fiber content than commercial Opuntia species. Furthermore, O. engelmannii showed a tendency to present the highest betacyanins, betaxanthins, and betalains contents. A total of 181, 122, 113, 183 and 140 different proteins were identified in OM, OP, OE, OFG, OFR species, respectively. All species showed the highest enrichment in three main pathways such as amino acids biosynthesis, glycolysis (dark)/gluconeogenesis (light), and the citric acid cycle. The wild prickly pear fruits of this study showed important nutritional, protein, and antioxidant properties with biological interest, and can be a potential source of functional ingredients and nutraceuticals.

A Novel Process for the Recovery of Betalains from Unsold Red Beets by Low-Temperature Enzyme-Assisted Extraction

Food waste management plays a central role in the circular economy. To our knowledge, only a few studies have investigated the use of unsold fruit and vegetables from supermarkets as a substitute source for the extraction of natural colorants. Thus, the aim of this paper was to suggest a green, tailored protocol that avoids the use of organic solvents for the recovery of betalains from unsold red beets for use as a food colorant. The recovery of such pigments was carried out by a tailored enzymatic mix, blended considering the polysaccharide composition of the beetroot cell wall; thus, it consisted of: cellulase (37%), xylanase (35%), and pectinase (28%). The enzyme-assisted extraction protocol was optimized, and the most suitable conditions (in terms of pigment yield and color attributes) for the recovery of betalains from unsold beets appeared to be: 25 U/g total dose of enzymatic mix, temperature 25 °C, and processing time 240 min.

Nutritional Evaluation of Beetroots (Beta vulgaris L.) and Its Potential Application in a Functional Beverage

Beetroot is a good source of minerals, fibers, and bioactive components. The present research work was conducted to evaluate the nutritional quality of beetroots (juice, peels, leaves and pomace) enhancing the extracted bioactive components, and developing a functional probiotic beverage. Chemical composition and minerals content of beetroot parts were estimated. The bioactive components were extracted by instant extraction method (IEM) and overnight extraction method (at -20°C) (OEM) to determine total phenolics, flavonoids, and DPPH inhibition ratio. The extracted beetroot juice was mixed with milk for valorization of the beverage nutritional value and fermented with LA-5 and ABT-5 cultures to create a novel functional beverage. Chemical composition, minerals content, and bioactive components of beverages were estimated. The leaves exhibited the highest calcium content (1200 mg/100g). Juice showed the highest amount of all minerals except for calcium and magnesium. Overnight extraction method (OEM) increased the antioxidant activity in peels and stems. Natural juice exhibited the highest activity compared to extracts. Fermentation of beet-milk beverage with LA-5 and ABT-5 cultures enhanced the beverage taste, flavor, and antioxidant capacity. Beetroot wastes and juice comprise a valuable nutritional source. Fermentation improved the nutritional value of beetroot and the acceptability of the product.

Three Types of Red Beetroot and Sour Cherry Based Marmalades with Enhanced Functional Properties

The importance of bioactive compounds such as betalains and anthocyanins was highlighted in the present study by the valorization of red beetroot and sour cherry as an attempt to develop healthy products. The aim of the study was to obtain and characterize three types of marmalade based on red beetroot, sour cherry and both in 1:1 combination, obtained by heating at 95 °C for 30 min. Changes in total phenolic content, total flavonoids, betalains, anthocyanins and antioxidant activity were evaluated before and after the thermal treatment. Several other analyses such as color, rheological and textural analyses and confocal laser microscopy were performed to provide further information about the quality of the added-value food products. A significant decrease of 34% in betalains content was registered in the red beetroot marmalade due to the chemical changes in bioactives induced by the temperature. A satisfactory ABTS radical scavenging activity of 8.12 ± 0.38 mMol Trolox/g dry weight (dw) was obtained for the red beetroot and sour cherry based marmalade. The gelled structure was validated by the rheological and textural characteristics. The results highlighted the potential use of red beetroot and sour cherry as food raw materials, due to their particular profile of bioactive compounds.

First description of betalains biosynthesis in an aquatic organism: characterization of 4,5-DOPA-extradiol-dioxygenase activity in the cyanobacteria Anabaena cylindrica

The biosynthesis of betalamic acid, the structural unit of pigments betalains, is performed by enzymes with 4,5-DOPA-extradiol-dioxygenase activity. These enzymes were believed to be limited to plants of the order Caryophyllales and to some fungi. However, the discovery of Gluconacetobacter diazotrophicus as the first betalain-forming bacterium opened a new field in the search for novel biological systems able to produce betalains. This paper describes molecular and functional characterization of a novel dioxygenase enzyme from the aquatic cyanobacterium Anabaena cylindrica. The enzyme was found to be a homodimer of a polypeptide of 17.8 kDa that, opposite to previous related enzymes, showed a strong inhibition by excess of the precursor L-DOPA. However, its heterologous expression has allowed detecting the formation of the main compounds in the biosynthetic pathway of betalains. In addition, phylogenetic analysis has shown that this enzyme is not close related to enzymes from plants, fungi or proteobacteria such as G. diazotrophicus. The presence of enzymes that produce these health-promoting compounds is more diverse than expected. The discovery of this novel dioxygenase in the phylum cyanobacteria expands the presence of betalamic acid-forming enzymes in organisms of different nature with no apparent relationship among them.

Stabilisation of betalains and phenolic compounds extracted from red cactus pear (Opuntia ficus-indica) by spray and freeze-drying using oca (Oxalis tuberosa) starch as drying aid

The objective of this work was to evaluate the stabilisation of betalains and phenolic compounds extracted from red cactus pear by spray and freeze-drying. After hydroethanolic extraction and partial solvent removal under reduced pressure, the highly coloured extracts were enriched with oca starch and maltodextrin as drying aids in different ratios (100:0, 70:30, and 50:50, oca starch: maltodextrin) prior to spray and freeze-drying. The obtained microencapsulated extract powders were characterised by moisture content, hygroscopicity, solubility and morphology. In addition, the stability of the encapsulated betalains and phenolics was evaluated during storage at room temperature for 105 days. All microcapsules showed high retentions of betacyanins (69.9-86.5% after 105 days), betaxanthins (72.2-81.9%), phenolic compounds (46.5-63.5%) and antioxidant capacity (60.1-64.9%, FRAP method; 49.7-57.5%, ABTS method). The system with 70:30 starch:maltodextrin ratio as drying aids showed the highest values of retention regarding the polyphenol content (63.5%), antioxidant capacity (64.9% to FRAP method) and betacyanin content (86.5%), as well as a low degradation rate constant of betacyanins (1.23 × 10^-3 days^-1) and a long half-life (563 days). Oca starch used alone or in combination with maltodextrin has been shown to work adequately as a microencapsulating agent and stabilizer of pigments and antioxidants derived from red cactus pear.

In vitro gastrointestinal stability, bioaccessibility and potential biological activities of betalains and phenolic compounds in cactus berry fruits (Myrtillocactus geometrizans)

Cactus berry (Myrtillocactus geometrizans) is a scarcely studied Mexican wild fruit. These fruits could contribute to reduce the risk of degenerative chronic diseases due to their bioactive profile. The aim of this work was to study the betalains and phenolic profile in cactus berry, their in vitro biological activities and gastrointestinal digestive stability and bioaccessibility. 43 metabolites were identified by HPLC-DAD-ESI-QTOF (8 betaxanthins, 8 betacyanins, 13 flavonoids, 6 phenolic acids). Phyllocactin and Isorhamnetin rhamnosyl-rutinoside (IG2) were the most abundant metabolites (5876 and 396 µg/g dw) which were also bioaccessible (16 and 21%, respectively). Pulps showed higher (p ≤ 0.05) antioxidant activity by the Oxygen Radical Absorbance Capacity (27 mM Trolox equivalents). The anti-hyperglycemic activity was highest (p ≤ 0.05) in peel and pulp tissues (85% α-glucosidase and 8% α-amylase inhibition). An 83% inhibition of hyaluronidase showed high anti-inflammatory activity. Cactus berry fruit should be considered a promising fruit candidate for a sustainable healthy diet.

Betanin as a multipath oxidative stress and inflammation modulator: a beetroot pigment with protective effects on cardiovascular disease pathogenesis

Oxidative stress is a common physiopathological condition enrolled in risk factors for cardiovascular diseases. Individuals in such a redox imbalance status present endothelial dysfunctions and inflammation, reaching the onset of heart disease. Phytochemicals are able to attenuate the main mechanisms of oxidative stress and inflammation and should be considered as supportive therapies to manage risk factors for cardiovascular diseases. Beetroot (Beta vulgaris L.) is a rich source of bioactive compounds, including betanin (betanidin-5-O-β-glucoside), a pigment displaying the potential to alleviate oxidative stress and inflammantion, as previously demonstrated in preclinical trials. Betanin resists gastrointestinal digestion, is absorbed by the epithelial cells of intestinal mucosa and reaches the plasma in its active form. Betanin displays free-radical scavenger ability through hydrogen or electron donation, preserving lipid structures and LDL particles while inducing the transcription of antioxidant genes through the nuclear factor erythroid-2-related factor 2 and, simultaneously, suppressing the pro-inflammatory nuclear factor kappa-B pathways. This review discusses the anti-radical and gene regulatory cardioprotective activities of betanin in the pathophysiology of endothelial damage and atherogenesis, the main conditions for cardiovascular disease. In addition, betanin influences on these multipath cellular signals and aiding in reducing cardiovascular disorders is proposed.

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.

Continuous Flow UV-C Irradiation Effects on the Physicochemical Properties of Aloe vera Gel and Pitaya (Stenocereus spp.) Blend

Physicochemical properties of a blend of 10% Aloe vera gel with 5% pitaya juice subjected to UV-C doses of 16.5, 27.7, and 40 mJ/cm2 were evaluated at pH 3.5 and 5.5. Unprocessed treatments were used as the control. The a* color parameter decreased and luminosity increased at pH 3.5. The decrease in the reddish color was consistent with the decrease in total betalains content and stabilized at pH 5.5. The NMR analyses of UV-C treatments showed changes in betalains signal patterns. Polyphenolics content was significantly reduced in the UV-C treatments at pH 5.5. UV-C processing decreased the antioxidant activity 1.25 times compared to unprocessed treatments. Total sugar content was reduced as the UV-C dose increased. Doses above 16.5 mJ/cm2 resulted in a higher simple sugar content at a pH 3.5. The UV-C continuous flow technology can be applied to stabilize betalains in Aloe vera-pitaya blends at a UV-C dose of 16.5 mJ/cm2 and pH 5.5.

The effects of betalain-rich cacti (dragon fruit and cactus pear) on endothelial and vascular function: a systematic review of animal and human studies

Dragon fruit (Hylocereus) and cactus pear (Opuntia) are cacti species that have been widely used globally as a reliable source of food as well as traditional folk remedies. They have become of scientific interest recently due to their high levels of bioactive phytochemical compounds, in particular betalains. Earlier systematic reviews have explored the impact of supplementation of these cactus species on obesity, type-2 diabetes mellitus and cardiovascular risk factors: body weight and composition, serum triglycerides, cholesterol, blood glucose and blood pressure. However, effects on vascular health and endothelial function have yet to be reviewed. In order to address this gap in the literature, a systematic review has been conducted to evaluate the physiological effects of Hylocereus and Opuntia cacti on endothelial and vascular function in in vivo animal models and human studies. An electronic search was performed in the following databases: PubMed (MEDLINE), EMBASE (via Ovid), CINAHL, Scopus, Web of Science®, and The Cochrane Library (CENTRAL). All journals were searched since inceptions up to January 2020 without language restriction. Outcomes of interest were blood pressure, arterial stiffness, vascular reactivity and biochemical markers of endothelial dysfunction. Two investigators independently performed the study selection and data extraction. From 394 references, only 16 studies (9 animal and 7 human) fulfilled the eligibility criteria. Animal studies suggested a potential increase in vasodilation and serum nitric oxide and a reduction in vascular stiffness and blood pressure. The small number of human studies showed a reduction in heart rate as well as an increase in heart rate variability. Although these findings appear to indicate improvement in vascular health, there is a severe lack of robust, randomised human intervention studies to identify underlying mechanisms, optimal dose and long-term effects of cacti consumption.

Inhibitory Effect of Betanin FromHylocereus ocamponisAgainst Steatohepatitis in Mice Fed a High-Fat Diet

Betanin is a phytocompound whose effect in steatohepatitis has not yet been tested. Betanin was extracted from the fruits of Hylocereus ocamponis, and its effects were evaluated in a mice model for non-alcoholic fatty liver disease. Six-week-old male BALB/c mice fed with a high-fat diet received 9.6 mg of betanin per day during 40 days. Body, liver, and epididymal fat pad weights and the levels of blood serum total cholesterol, triglycerides, high-density lipoproteins, alanine aminotransferase, blood nitrogen urea, creatinine, and total antioxidant capacity were measured. Hepatosteatosis and inflammatory infiltration were categorized, and the relative cell area of hepatocytes was determined. Betanin inhibited the inflammatory infiltration of the liver ( P = 4.000 × 10−6) and the necrosis of hepatocytes ( P = 9.634 × 10−7); it also produced a predominance of microvesicular steatosis ( P = 9.634 × 10−7), decreased epididymal fat pad weight ( P = 8.250 × 10−4), and increased blood serum total cholesterol ( P = 0.011). Betanin is a promising compound for fatty liver, steatohepatitis, and chronic liver disease.

Nanoliposomal encapsulation mediated enhancement of betalain stability: Characterisation, storage stability and antioxidant activity of Basella rubra L. fruits for its applications in vegan gummy candies

Betalains are violet-red, natural food grade pigments with health benefits; however, their stability limits its use in industrial food processing. This can be overcome by placing the betalains in lecithin nanoliposomes (NLs), which causes a 76% improvement of betalain colour and stability. Extended sonication time (8 min) lowered the zeta potential (-47.5 to -40.8), and particle size (74.23 to 55.35 nm). Zeta potential, particle size, and polydispersity index of Betalain NLs (BNLs) didn't change significantly during storage (40 days). Degradation in the colour of BNLs was observed only at 121 °C (20 min) while the native juice degraded at 100 °C (20 min). BNLs were incorporated in gummy candies (GuCa) to improve its colour stability. The betalain retention, colour, texture, antioxidant activity, and shelf-life of the GuCa during storage (5 °C, 28 days) demonstrated the efficacy of BNLs to be explored as a natural colourant for the food industry.

Chemical characterization, antioxidant capacity, and anti-hyperglycemic effect of Stenocereus stellatus fruits from the arid Mixteca Baja region of Mexico

The tunillo (Stenocereus stellatus [Pfeiffer] Riccobono) is a relatively little known cactus fruit with a significant pharmacological potential. However, all currently known variants are identified visually mostly on the basis of pulp color. Differences in chemical composition and pharmacological properties also remain largely unknown. Support vector machine classifiers were applied to UV-Visible spectra of liquid samples to obtain the following, color-based categories of tunillo fruits: A1-white, A2-red, A3-purple, and A4-orange. The spectrum of A2-red could be duplicated by combining those from A3-purple and A4-orange, while UPGMA-based hierarchical clustering of psbA-trnH and matK suggested that certain differences in color might actually have a genetic basis. The pigment quantification established A2-red and A3-purple as the most suitable candidates for the extraction of betalains and complex colored matrices, respectively. A2-red also had the highest content of phenols and flavonoids and displayed a noticeable anti-hyperglycemic effect.

Could fruits be a reliable source of food colorants? Pros and cons of these natural additives

Color additives are important for the food industry to improve sensory quality lost during food process and to expand the variety of products. In general, artificial colorants have lower cost and better stability than the natural ones. Nevertheless, studies have reported their association with some health disorders. Furthermore, consumers have given greater attention to food products with health beneficial effects, which has provided a new perspective for the use of natural colorants. In this context, fruits are an excellent alternative source of natural compounds, that allow the obtainment of a wide range of colorant molecules, such as anthocyanins, betalains, carotenoids, and chlorophylls. Furthermore, in addition to their coloring ability, they comprise different bioactive properties. However, the extraction and application of natural colorants from fruits is still a challenge, since these compounds show some stability problems, in addition to issues related to the sustainability of raw-materials providing. To overcome these limitations, several studies have reported optimized extraction and stabilization procedures. In this review, the major pigments found in fruits and their extraction and stabilization techniques for uses as food additives will be looked over.