LC-MS/MS, GC-MS and molecular docking analysis for phytochemical fingerprint and bioactivity of Beta vulgaris L.

The plants that we consume in our daily diet and use as a risk preventer against many diseases have many biological and pharmacological activities. In this study, the phytochemical fingerprint and biological activities of Beta vulgaris L. leaf extract, which are widely consumed in the Black Sea region, were investigated. The leaf parts of the plant were dried in an oven at 35 °C and then ground into powder. The main constituents in B. vulgaris were identified by LC-MS/MS and GC-MS analyses. Phenolic content, betaxanthin and betacyanin levels were investigated in the extracts obtained using three different solvents. The biological activity of the extract was investigated by anti-microbial, anti-mutagenic, anti-proliferative and anti-diabetic activity tests. Anti-diabetic activity was investigated by in vitro enzyme inhibition and in-silico molecular docking was performed to confirm this activity. In the LC-MS analysis of B. vulgaris extract, a major proportion of p_coumaric acid, vannilin, protecatechuic aldehyde and sesamol were detected, while the major essential oils determined by GC-MS analysis were hexahydrofarnesyl acetone and phytol. Among the solvents used, the highest extraction efficiency of 2.4% was obtained in methanol extraction, and 36.2 mg of GAE/g phenolic substance, 5.1 mg/L betacyanin and 4.05 mg/L betaxanthin were determined in the methanol extract. Beta vulgaris, which exhibited broad-spectrum anti-microbial activity by forming a zone of inhibition against all tested bacteria, exhibited anti-mutagenic activity in the range of 35.9-61.8% against various chromosomal abnormalities. Beta vulgaris extract, which did not exhibit mutagenic, sub-lethal or lethal effects, exhibited anti-proliferative activity by reducing proliferation in Allium root tip cells by 21.7%. 50 mg/mL B. vulgaris extract caused 58.9% and 55.9% inhibition of α-amylase and α-glucosidase activity, respectively. The interactions of coumaric acid, vanniline, hexahydrofarnesyl acetone and phytol, which are major compounds in phytochemical content, with α-amylase and α-glucosidase were investigated by in silico molecular docking and interactions between molecules via various amino acids were determined. Binding energies between the tested compounds and α-amylase were obtained in the range of - 4.3 kcal/mol and - 6.1 kcal/mol, while for α-glucosidase it was obtained in the range of - 3.7 kcal/mol and - 5.7 kcal/mol. The biological activities of B. vulgaris are closely related to the active compounds it contains, and therefore studies investigating the phytochemical contents of plants are very important. Safe and non-toxic plant extracts can help reduce the risk of various diseases, such as diabetes, and serve as an alternative or complement to current pharmaceutical practices.

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.

Influence of High-Pressure Homogenization on the Physicochemical Properties and Betalain Pigments of Red Beetroot (Beta vulgaris L.) Juice.

High-pressure homogenization (HPH) is considered an innovative and modern method of processing and preserving liquid and semi-liquid foods. The aim of this research was to examine the impact of HPH processing on the content of betalain pigments and physicochemical properties of beetroot juice. Combinations of the following HPH parameters were tested: the pressure used (50, 100, 140 MPa), the number of cycles (1 and 3) and the applied cooling or no cooling. The physicochemical analysis of the obtained beetroot juices was based on the determination of the extract, acidity, turbidity, viscosity and color values. Use of higher pressures and a greater number of cycles reduces the turbidity (NTU) of the juice. Moreover, in order to maintain the highest possible extract content and a slight color change of the beetroot juice, it was crucial to perform sample cooling after the HPH process. The quantitative and qualitative profiles of betalains have been also determined in the juices. In terms of the content of betacyanins and betaxanthins, the highest values were found in untreated juice at 75.3 mg and 24.8 mg per 100 mL, respectively. The high-pressure homogenization process resulted in a decrease in the content of betacyanins in the range of 8.5-20.2% and of betaxanthins in the range of 6.5-15.0%, depending on the parameters used. Studies have shown that that the number of cycles was irrelevant, but an increase in pressure from 50 MPa to 100 or 140 MPa had a negative effect on pigment content. Additionally, juice cooling significantly limits the degradation of betalains in beetroot juice.

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.

[Natural pigments in fruit and vegetable juices: the content of anthocyanins, carotenoids and betalaines].

The color of the juice is determined by the color of the corresponding fruit or vegetable from which the juice is made. The color of a fruit or vegetable, in turn, is determined by the presence of natural coloring pigments - secondary plant metabolites, which include mainly anthocyanins, carotenoids and betalains. These substances, in addition to bright colors, give the juices properties that largely provide a positive effect on health. The quantitative content of these pigments in juices (especially in commercially produced juices, the most commonly consumed by the population at present) is important for understanding of the contribution of that juices in real intake of these bioactive compounds with diet. The purpose of the work was to study the content of anthocyanins, carotenoids and betalaines in juices a nd nectars (cherry, pomegranate, red grapes, tomato, carrot, peach and vegetable juices containing red beetroot) widely represented on the Russian market. Material and methods. The content of natural coloring pigments was determined by HPLC: anthocyanins - according to GOST 32709-2014 "Juice products. Methods for the determination of anthocyanins¼, carotenoids - in accordance with R 4.1.1672-03 "Guidelines for methods of quality control and safety of biologically active food supplements", betalains by revised IFU method of analysis No 71 (rev. 2023) "Anthocyanins and Betalains by HPLC". The results of measurements in 66 samples selected from Russian retail chains were analyzed. Results. The highest content of anthocyanins (in terms of cyanidin-3-O-glucoside) was found in cherry nectars - an average of 11.4 mg/100 cm3, lower values were obtained for red grape juices (an average of 2.5 mg/100 cm3) and pomegranate juices (0.9 mg/100 cm3). In tomato juices, in addition to lycopene (7.0-14.1 mg/100 cm3), ß-carotene was found in an amount of 0.3- 1.2 mg/100 cm3. In carrot juices, the content of ß-carotene was at the level of 5.7-12.5 mg/100 cm3, in peach nectars - 0.14- 0.38 mg/100 cm3. The highest concentrations of betalains were found in directly pressed red beet juice at a level of 156.2 mg/100 cm3, with a predominance of betacyanins (99.4 mg/100 cm3) over betaxanthins (56.8 mg/100 cm3). The content of betacyanins decreased to 51.5 mg/100 cm3 in directly pressed lacto-fermented juice and to 2-3 mg/100 cm3 in multi-vegetable juices; betaxanthins were not detected in these samples. Conclusion. The study showed high levels of natural coloring substances - anthocyanins, carotenoids and in some extent betalains in juice products. A serving (200 cm3) of cherry nectar can provide up to 100% of an adequate daily intake of anthocyanins, a serving of red grape juice and a serving of pomegranate juice can provide up to 20% and up to 10%, respectively. The content of ß-carotene in a serving of carrot juice is several times higher than the daily requirement for adults; a serving of peach nectar contains up to 10% of the daily requirement for ß-carotene. Tomato juice is rich in lycopene, this carotenoid content in a serving is several times higher than the adequate daily intake, while the content of ß-carotene is also at a high level - up to 50% of the daily requirement for this substance. Despite the fact that direct data on the adequate daily intake of betalains have not yet been established, relatively high concentrations of betalains, especially in directly pressed red beet juices, determine their significant potential in increasing the nutritive value of the diet through beet-based juices intake.

Design, Synthesis and Gene Modulation Insights into Pigments Derived from Tryptophan-Betaxanthin, Which Act against Tumor Development in Caenorhabditis elegans.

The use of betalains, which are nitrogenous plant pigments, by the food industry is widespread and reflects their safety after intake. The recent research showed outstanding results for L-tryptophan-betaxanthin, a phytochemical present in traditional Chinese medicine, as an antitumoral agent when the activity was evaluated in the animal model Caenorhabditis elegans. Thus, L-tryptophan-betaxanthin is now presented as a lead compound, from which eleven novel structurally related betaxanthins have been designed, biotechnologically produced, purified, and characterized. The antitumoral effect of the derived compounds was evaluated on the JK1466 tumoral strain of C. elegans. All the tested molecules significantly reduced the tumoral gonad sizes in a range between 31.4% and 43.0%. Among the novel compounds synthesized, tryptophan methyl ester-betaxanthin and tryptophan benzyl ester-betaxanthin, which are the first betalains to contain an ester group in their structures, caused tumor size reductions of 43.0% and 42.6%, respectively, after administration to the model animal. Since these were the two most effective molecules, their mechanism of action was investigated by microarray analysis. Differential gene expression analysis showed that tryptophan methyl ester-betaxanthin and tryptophan benzyl ester-betaxanthin were able to down-regulate the key genes of the mTOR pathway, such as daf-15 and rict-1.

Bioaccessibility of Betalains in Beetroot (Beta vulgaris L.) Juice under Different High-Pressure Techniques.

The influence of high hydrostatic pressure (HHP) and supercritical carbon dioxide (SCCD) on the bioaccessibility of betalains in beetroot (Beta vulgaris L.) juice was investigated. Freshly squeezed juice (FJ) was treated at a mild temperature of 45 °C for 10 min (T45), pasteurization at 85 °C for 10 min (T85), HHP at 200, 400, and 500 MPa at 20 °C for 5 min (HHP200, HHP400, HHP500) and SCCD at 10, 30 and 60 MPa at 45 °C for 10 min (SCCD10, SCCD30, SCCD60). The juice was subjected to an in vitro digestion system equipped with dialysis. The content of betalains was measured with the aid of a High-Performance Liquid Chromatography (HPLC), the antioxidant capacity (AC) (ABTS•+, DPPH•) was analyzed during each digestion step, and the bioaccessibility of betacyanins and betaxanthins was assessed. The SCCD at 30 and 60 MPa significantly increased pigments' bioaccessibility compared with other samples. The 30 MPa proved particularly advantageous, as it increased the bioaccessibility of the total betacyanins and the betaxanthins by 58% and 64%, respectively, compared to the T85 samples. Additionally, higher bioaccessibility of betacyanins was noted in HHP200 and HHP400, by 35% and 32%, respectively, compared to FJ, T45, and T85 samples. AC measured by ABTS•+ and DPPH• assays were not unequivocal. However, both assays showed significantly higher AC in SCCD60 compared to T85 (21% and 31%, respectively). This research contributed to the extended use of the HHP and/or SCCD to design food with higher health-promoting potentials.

Composition, Color Stability and Antioxidant Properties of Betalain-Based Extracts from Bracts of Bougainvillea.

Betalains in bracts of Bougainvillea are of great application potential as natural food colorants and antioxidants. This study explored the color, spectra, composition, storage stability, and antioxidant properties of betalain-based Bougainvillea bracts extracts (BBEs) to verify their application value. The results showed that Bougainvillea bract color variance is due to varied contents and proportions of betacyanins (Bc) and betaxanthins (Bx). Bc or Bx alone determined hues of purple or yellow, respectively; the co-existence of Bc and Bx would produce varied hues of red. BBEs showed bright color and good antioxidant properties under a wide pH range. The pH range of 5−6 was optimal for the highest color stability, and pHs 3−8 were optimal for stronger antioxidants. Bc mainly underwent color fading during storage, while Bx easily produced dark precipitates or melanism under strong acidic (pH < 4) or alkaline conditions (pH > 8). However, Bougainvillea Bx showed 3−4 times higher antioxidant ability than Bc. Different considerations for Bc and Bx are needed for varied application purposes. The purple bracts containing only Bc would be more suitable as colorant sources, while additional Bx can bring enhancement of antioxidant ability and richness of Bougainvillea extract color.

Betalain Extracts from Beetroot as Food Colorants: Effect of Temperature and UV-Light on Storability.

Beetroot is a good source of natural food colorants given that it contains significant amount of betalain pigments. This study investigates the three-months storage stability of betalain extracts recovered from unsold beetroot by a specific enzymatic mix. The extract storability was evaluated by the kinetic degradation model of betacyanins and betaxanthins, as well as by pigment color attributes (CIELa*b* parameters) under dark and UV-light exposure at different temperatures (4, 25 and 40 °C). Considering all the tested storage conditions, betaxanthins appeared to be more stable than betacyanins in terms of degradation rate constant, half-life time and activation energy. The effect of UV-light was negligible if the pigment was not exposed to temperatures higher than the room one, since no relevant differences were found between the parameters studied at 4 and 25 °C. Taking into account the visual color, all the investigated color indexes (total color difference, chroma and hue) were mainly affected by temperature, even if mildly high (40 °C), and to a lesser extent by UV-light exposure.

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

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.

Comparative UHPLC-HRMS Profiling, Toxicological Assessment, and Protection Against H2O2-Induced Genotoxicity of Different Parts of Opuntia ficus indica.

Opuntia ficus indica has been an important dietary source and a traditionally used medicinal plant. Given the promising health-promoting properties of this plant, a comparative toxicological assessment and antioxidant bioevaluation of extracts from different parts of the plant were carried out in relation to their chemical profile. Toxicity was examined at multiple endpoints using the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT), Comet and the γH2AX In-Cell Western Assay, while hyphenated ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) analysis was carried out to identify main constituents. None of the extracts showed any cytotoxic and genotoxic effect on cell lines used, apart from the flower extract in HepG2 cells at the highest concentration tested (2.5 mg/mL). Both fruit flesh and seed extracts demonstrated a prominent protective effect against H2O2-induced genotoxicity in almost all concentrations tested, while extracts originated from flowers and cladodes were effective only at the low non-cytotoxic (0.312 and 0.625 mg/mL) and high (1.25 and 2.5 mg/mL) concentrations, respectively. In total, 2 phenolic acids, 12 flavonoids, along with 3 feruloyl derivatives and the plant pigment indicaxanthin, were tentatively identified by UHPLC-HRMS analysis. Phenolic acids (compounds 1 and 2) were mainly distributed in cladodes (64.6%), while flavonoids (3-14) in the flowers (81.8%). Overall, the highest amount of total flavonoids (22.76 ± 0.015 mg of quercetin equivalent [QE]/g) and total phenolics (62.80 ± 0.009 mg gallic acid equivalents [GAE]/g) was found in the flower extract. Flavonoid glycosides have not been detected in the seeds and the flesh, while the fruit seed extract contained mainly feruloyl derivatives. Our data provide convincing evidences for the lack of cytotoxic and genotoxic effects of O. ficus indica aqueous extracts and, in parallel, support the potential for further exploitation of this plant in the food supplement or functional food sector.

Extension of life-span using a RNAi model and in vivo antioxidant effect of Opuntia fruit extracts and pure betalains in Caenorhabditis elegans.

Betalains are nitrogenous plant pigments known for their high antioxidant capacity. For the first time, this antioxidant nature has been studied in an in vivo system using the model organism Caenorhabditis elegans. The oxidative stress caused in the fluorescent strain TJ375 (hsp-16.2::GFP) was reversed by the presence of both natural and semi-synthetic betalains, with an ED50 value around 25 µM for betacyanins and up to 10 µM for betaxanthins, with indicaxanthin, the major pigments in prickly pear fruits, as the most effective betalain. The effect of model betalains on the lifespan of the wild-type N2 strain was carefully studied using the automatic platform "Lifespan Machine". In a search for different approaches to suppress progeny, pop-1 RNAi was used to avoid FUdR use. The presence of betalains in the medium, both as pure compounds and as enriched Opuntia extracts significantly increased the lifespan of C. elegans.

Indicaxanthin from Opuntia Ficus Indica (L. Mill) impairs melanoma cell proliferation, invasiveness, and tumor progression.

BACKGROUND: A strong, reciprocal crosstalk between inflammation and melanoma has rigorously been demonstrated in recent years, showing how crucial is a pro-inflammatory microenvironment to drive therapy resistance and metastasis. PURPOSE: We investigated on the effects of Indicaxanthin, a novel, anti-inflammatory and bioavailable phytochemical from Opuntia Ficus Indica fruits, against human melanoma both in vitro and in vivo. STUDY DESIGN AND METHODS: The effects of indicaxanthin were evaluated against the proliferation of A375 human melanoma cell line and in a mice model of cutaneous melanoma. Cell proliferation was assessed by MTT assay, apoptosis by Annexin V-Fluorescein Isothiocyanate/Propidium Iodide staining, protein expression by western blotting, melanoma lesions were subcutaneously injected in mice with B16/F10 cells, chemokine release was quantified by ELISA. RESULTS: Data herein presented demonstrate that indicaxanthin effectively inhibits the proliferation of the highly metastatic and invasive A375 cells as shown by growth inhibition, apoptosis induction and cell invasiveness reduction. More interestingly, in vitro data were paralleled by those in vivo showing that indicaxanthin significantly reduced tumor development when orally administered to mice. The results of our study also clarify the molecular mechanisms underlying the antiproliferative effect of indicaxanthin, individuating the inhibition of NF-κB pathway as predominant. CONCLUSION: In conclusion, we demonstrated that indicaxanthin represents a novel phytochemical able to significantly inhibit human melanoma cell proliferation in vitro and to impair tumor progression in vivo. When considering the resistance of melanoma to the current therapeutical approach and the very limited number of phytochemicals able to partially counteract it, our findings may be of interest to explore indicaxanthin potential in further and more complex melanoma studies in combo therapy, i.e. where different check points of melanoma development are targeted.

Implications of the Red Beet Ripening on the Colour and Betalain Composition Relationships.

The evolution during ripening of Beta vulgaris (var. Pablo) on colour and betalain composition, not previously conducted in conjunction in red beets, has been examined. According to the results, it could be asserted that the ripening stage significantly (p < 0.05) influenced on all the studied parameters. On the basis of the betalain content, the optimum ripening stage corresponded to a medium weigh-to-calibre ratio, in the light of the significantly (p < 0.05) higher content of betalains, especially betanin and vulgaxanthin I. Moreover, colour attributes also differed during ripening, having the medium-ripened beetroots a significantly (p < 0.05) more reddish hue (hab) and lower lightness (L*), probably due to the higher content of betaxanthins in this stage. The colour differences among red beets in the stage II and the rest of stages were visually appreciable (ΔE*ab > 3) and mainly qualitative. A new range of opportunities for diversification of colorant market, from a nutritional and colorimetric point of view, could be possible by employing red beets with different stages of ripening.

Encapsulation of cactus (Opuntia megacantha) betaxanthins by ionic gelation and spray drying: A comparative study.

The encapsulation of betaxanthins from orange Opuntia megacantha fruits was performed as a stabilisation strategy for these natural pigments. Betaxanthin-rich extract (BE) was encapsulated by two methodologies, spray drying (SD) and ionic gelation (IG). Encapsulates were obtained by using two encapsulating agents (EA), a mixture of maltodextrin-cactus cladode mucilage and sodium alginate (SA) for SD and IG, respectively. Their properties were compared with the freeze-dried cactus fruit pulp (CP) as control. Total betaxanthin content, moisture content, water activity (aw), particle size, morphology by SEM, colour parameters (CIELab), and thermogravimetric properties were analysed in the encapsulates. Additionally, the antioxidant activity, total dietary fibre content, and pigment stability of encapsulates under two relative humidity conditions were also evaluated. The results showed that the encapsulation technique, EA concentration, and the BE/EA ratio affected the particle size and morphology, the glass transition temperature, and the mass loss of encapsulated materials. The best pigment stabilisation was obtained for the SD capsules, although both encapsulation techniques allowed improving the pigment stability in comparison with the CP taken as control. These results provided evidence that betaxanthins from Opuntia megacantha have the potential to be used as natural pigments, soluble in water, with functional properties for the food industry.

Betaxanthin-Rich Extract from Cactus Pear Fruits as Yellow Water-Soluble Colorant with Potential Application in Foods.

Cactus pear (Opuntia ficus-indica) fruit juice is a source of betaxanthin pigments which can be used as a natural yellow food colorant. The HPLC chromatographic pigment pattern corresponding to the betaxanthin-rich extract revealed the presence of four betaxanthins, of which indicaxanthin (proline-betaxanthin) accounts for around 85%. A betaxanthin-rich water-soluble food colorant from cactus pears fruits was produced by spray-drying microencapsulation using maltodextrin as a wall material. The resulting powder was characterized by scanning electron microscopy, and its apparent color was analyzed by spectrometry. The stability of the microcapsules was examined at +20, +4 and -20 °C in the dark during six months of storage. The degradation of betaxanthins was delayed by microencapsulation and their colorant stability increased at lower temperatures. The potential application of the colorant microcapsules was successfully assessed in two food model systems: a yogurt and a soft-drink. Both foods presented an attractive pale yellow color. Pigment retention and color parameters were investigated during storage under controlled conditions. Slight changes in the pigment retention, in both model systems, pointed to excellent preservation in the dark, even after 28 days at 4 °C. However, the presence of light contributed to betaxanthin deterioration. Spray-drying microencapsulation succeeds in reducing volumen of the pigment extract and can be easy in storage and delivery of the powders. It is proved to be a suitable process that can be recommended for stabilizing betaxanthins from cactus pears to be used as water-soluble natural colorants in foods.

Stability of spray-dried beetroot extract using oligosaccharides and whey proteins.

The properties and stability of spray-dried beetroot extract using maltodextrin (MD), inulin (IN), and whey protein isolate (WPI) as carrier agents were evaluated. The values of moisture, betalains content, and retention were 3.33-4.24%, 348.79-385.47 mg/100 g (dry-basis), and 88.45-95.69%, respectively. Higher values of antioxidant activity were observed for the treatments using WPI. The treatment with inulin alone presented higher hygroscopicity in the moisture adsorption isotherms at 25 °C and lower thermal stability when evaluating the thermogravimetric curves. When stored at 60 °C, the use of WPI alone conferred lower stability to the beetroot extract powder. In general, the simultaneous use of IN and WPI as carrier agents resulted in good stability of the beetroot extract powder, representing an opportunity for innovation in food products.

Betaxanthins and antioxidant capacity in Stenocereus pruinosus: Stability and use in food.

Betalains are important pigments for the food, pharmaceutical, and cosmetics industry. In the yellow Stenocereus pruinosus fruits (pitayas), total betalain concentration, Folin-Ciocalteu reduction capacity, and antiradical capacity per dry weight were 2345.9µgg-1, 7.3mg gallic acid equivalentsg-1, and 48.8µmol Trolox equivalentg-1, respectively. The stability of betaxanthins, which represent 89% of total betalains in yellow pitayas, was evaluated over a range of pH, temperature, as well as in the presence of food additives. Maximum stability was observed at pH6.6, and addition of ascorbic acid increased the half-life 1.8 times. Thermal stability at pH6.48±0.05 was also evaluated from 50°C to 80°C, over which the activation energy for betaxanthin degradation was determined to be 66.2kJmol-1. Model gelatin gummies and beverages were then prepared with pitaya juice or pulp, and pigment retention and color parameters were investigated during storage under various conditions. To match the yellow color of commercial products, gummies were supplemented with 4.6% w/w juice or pulp, and beverages were supplemented with 5% w/v juice, achieving H° values of 69.0-86.2° and 64.6-87.1°, respectively. Results indicate that betaxanthins were more stable in gummies than in beverages, and that pigment retention increased when products were stored in the dark or at low temperatures. Also, different changes in color during storage were observed between gummies and beverages.

The plasma bioavailability of nitrate and betanin from Beta vulgaris rubra in humans.

PURPOSE: To evaluate the plasma bioavailability of betanin and nitric oxide (NOx) after consuming beetroot juice (BTJ) and whole beetroot (BF). BTJ and BF were also analysed for antioxidant capacity, polyphenol content (TPC) and betalain content. METHODS: Ten healthy males consumed either 250 ml of BTJ, 300 g of BF or a placebo drink, in a randomised, crossover design. Venous plasma samples were collected pre (baseline), 1, 2, 3, 5 and 8 h post-ingestion. Betanin content in BTJ, BF and plasma was analysed with reverse-phase high-performance liquid chromatography (HPLC) and mass spectrometry detection (LCMS). Antioxidant capacity was estimated using the Trolox equivalent antioxidant capacity (TEAC) and polyphenol content using Folin-Ciocalteu colorimetric methods [gallic acid equivalents (GAE)] and betalain content spectrophotometrically. RESULTS: TEAC was 11.4 ± 0.2 mmol/L for BTJ and 3.4 ± 0.4 µmol/g for BF. Both BTJ and BF contained a number of polyphenols (1606.9 ± 151 mg/GAE/L and 1.67 ± 0.1 mg/GAE/g, respectively), betacyanins (68.2 ± 0.4 mg/betanin equivalents/L and 19.6 ± 0.6 mg/betanin equivalents/100 g, respectively) and betaxanthins (41.7 ± 0.7 mg/indicaxanthin equivalents/L and 7.5 ± 0.2 mg/indicaxanthin equivalents/100 g, respectively). Despite high betanin contents in both BTJ (~194 mg) and BF (~66 mg), betanin could not be detected in the plasma at any time point post-ingestion. Plasma NOx was elevated above baseline for 8 h after consuming BTJ and 5 h after BF (P < 0.05). CONCLUSIONS: These data reveal that BTJ and BF are rich in phytonutrients and may provide a useful means of increasing plasma NOx bioavailability. However, betanin, the major betalain in beetroot, showed poor bioavailability in plasma.