Solid-phase extraction of betanin and isobetanin from beetroot extracts using a dipicolinic acid molecularly imprinted polymer

Semisynthesis of Betaxanthins from Purified Betacyanin of Opuntia dillenii sp.: Color Stability and Antiradical Capacity

The availability of pure individual betalains in sufficient quantities which permit deeper understanding is still a challenge. This study investigates the high-yielding semisynthesis of betaxanthins using betalamic acid from a natural source (Opuntia dillenii), followed by condensation with ʟ-amino acids and further purification. Moreover, the color stability of the four synthesized individual betaxanthins, namely proline (ʟ-ProBX), alanine (ʟ-AlaBX), leucine (ʟ-LeuBX), and phenylalanine (ʟ-PheBX) betaxanthins, was investigated at different pHs. Their relative contribution to free radical scavenging was also scrutinized by TEAC and DPPH. ʟ-AlaBX and ʟ-LeuBx showed a significantly (p < 0.05) higher antioxidant activity, whereas ʟ-ProBX was the most resistant to the hydrolysis of betaxanthin and hence the least susceptible to color change. The color stability was strongly influenced by pH, with the color of ʟ-ProBX, ʟ-LeuBX, and ʟ-AlaBX at pH 6 being more stable, probably due to the easier hydrolysis under acid conditions. The semisynthesis and purification allowed us to have available remarkable quantities of pure individual betaxanthins of Opuntia dillenii for the first time, and to establish their color properties and antioxidant capacity. This study could be a step forward in the development of the best natural food colorant formulation, based on the betalain structure, which is of special interest in food technology.

A Comparative Study of Ethanol and Citric Acid Solutions for Extracting Betalains and Total Phenolic Content from Freeze-Dried Beetroot Powder

This research compares the extraction of betalains (betacyanin and betaxanthin) and total phenolic content using citric acid and aqueous-ethanol solutions. The aim is to find an environmentally sustainable alternative solvent for extracting these compounds from dried beetroot powder. Using citric acid solution as a solvent offers several benefits over ethanol. Citric acid is a weak organic acid found naturally in citrus fruits, making it a safe and environmentally friendly choice for certain extraction processes. Moreover, the use of citric acid as solvent offers biodegradability, non-toxicity, non-flammability, and is cost effective. A full factorial design and response surface methodology (RSM) were employed to assess the effects of extraction parameters (extraction time (5-30 min), extraction temperature (20, 30, 40 °C), pH of citric acid solution (3, 4, 5) and ethanol concentration (10, 20, 30% v/v)). The yield was determined spectrophotometrically and expressed as mg/g of dry powder. The results showed that citric acid solution yielded 85-90% of the ethanolic extract under identical conditions. The maximum yields of betacyanin, betaxanthin, and total phenolic content in citric acid solution were 3.98 ± 0.21 mg/g dry powder, 3.64 ± 0.26 mg/g dry powder, and 8.28 ± 0.34 mg/g dry powder, respectively, while aqueous-ethanol yielded 4.38 ± 0.17 mg/g dry powder, 3.95 ± 0.22 mg/g dry powder, and 8.45 ± 0.45 mg/g dry powder. Optimisation resulted in maximum extraction yields of 90% for betalains and 85% for total phenolic content. The study demonstrates the potential of citric acid as a viable alternative to polar organic solvents for extracting phytochemicals from plant material, providing comparable results to aqueous-ethanol. Artificial Neural Network (ANN) models outperformed RSM in predicting extraction yields. Overall, this research highlights the importance of exploring bio-solvents to enhance the environmental sustainability of phytochemical extraction.

Effect of an Antioxidant Based on Red Beetroot Extract on the Abiotic Stability of Polylactide and Polycaprolactone

This study investigated the effect of natural antioxidants inherent to beetroot (Beta vulgaris var. Vulgaris) on the ageing of environmentally friendly plastics. Certain properties were examined in this context, comprising thermal, mechanical, and morphological properties. A visual evaluation of relevant changes in the given polymers (polylactide and polycaprolactone) was conducted during an ageing test in a UV chamber (45 °C, 70% humidity) for 720 h. The films were prepared by a casting process, in which samples with the extract of beetroot were additionally incorporated in a common filler (bentonite), this serving as a carrier for the extract. The results showed the effect of the incorporated antioxidant, which was added to stabilize the biodegradable films. Its efficiency during the ageing test in the polymers tended to exceed or be comparable to that of the reference sample.

Complementary and alternative medicine (CAM) supplements in cancer outpatients: analyses of usage and of interaction risks with cancer treatment

Purpose

The aim of our study was to analyze the use of complementary and alternative medicine (CAM) supplements, identify possible predictors, and analyze and compile potential interactions of CAM supplements with conventional cancer therapy.

Methods

We included outpatient cancer patients treated at a German university hospital in March or April 2020. Information was obtained from questionnaires and patient records. CAM–drug interactions were identified based on literature research for each active ingredient of the supplements consumed by the patients.

Results

37.4% of a total of 115 patients consumed CAM supplements. Potential interactions with conventional cancer treatment were identified in 51.2% of these patients. All types of CAM supplements were revealed to be a potential source for interactions: vitamins, minerals, food and plant extracts, and other processed CAM substances. Younger age (< 62 years) (p = 0.020, φc = 0.229) and duration of individual cancer history of more than 1 year (p = 0.006, φc = 0.264) were associated with increased likelihood of CAM supplement use. A wide range of different CAM supplement interactions were reviewed: effects of antioxidants, cytochrome (CYP) interactions, and specific agonistic or antagonistic effects with cancer treatment.

Conclusion

The interaction risks of conventional cancer therapy with over-the-counter CAM supplements seem to be underestimated. Supplements without medical indication, as well as overdoses, should be avoided, especially in cancer patients. To increase patient safety, physicians should address the risks of interactions in physician–patient communication, document the use of CAM supplements in patient records, and check for interactions.

Recent developments in emerging technologies for beetroot pigment extraction and its food applications

Beetroot is well known for its deep red-purple colouring pigments called betalains. Betalains also found its application in the preparation of functional foods and drinks. Therefore, extraction of pigments with higher recovery and stability is the prime need for the industry. Conventional extraction techniques such as maceration, grinding or pressing have reported low yield of betalains and required large volume of solvent and energy. On the other hand, emerging technologies such as ultrasound, microwave and pulse electric field techniques are highly efficient processes and can achieve higher recovery. In this regard, this review provides an in-depth discussion on the various extraction methods and factors affecting the stability of betalains using conventional and emerging technologies. The recent applications of pigments in various food systems are also presented. Finally, challenges and future prospects of extraction and application of beetroot pigment have been identified and discussed.

Molecularly imprinted polymer solid phase extraction coupled with liquid chromatography-high resolution mass spectrometry for the detection of gonyautoxins 2&3 in seawater

Paralytic shellfish toxins (PSTs) cause risks to human health through food chains. Understanding the change of PSTs in seawater is critical for predicting the safety of seafood. Most reported methods for the detection of PSTs in microalgae or shellfish are not applicable in seawater because of extremely low concentration and matrix interferences. High resolution mass spectrometry (HRMS), quadrupole exactive orbitrap detects molecular ions accurately, and molecularly imprinted solid-phase extraction (MISPE) is recognized effective to reduce the matrix interference. GTXs 2&3 are two of common marine toxins in PSTs. In this study, a sensitive method consisting MISPE and liquid chromatography LC-HRMS was developed for the detection of GTXs 2&3 with a limit of detection (LOD) of 47.4 ng/L in seawater. With this method, samples obtained from the estuaries of the Shuangtaizi and Daliao Rivers were analyzed, and the results indicated the concentrations were lower than LOD in the area under investigation.

Development of a Novel Thin-Layer Chromatographic Method of Screening the Red Beet (Beta vulgaris L.) Pigments in Alimentary Products

The aim of this study was to develop a thin-layer chromatographic method of qualitative analysis, aiming to confirm the presence of the red beetroot pigments in a given sample. The TLC system developed for this purpose consists of the precoated RP-18 F254s TLC plates and the acetonitrile + methanol + water + glacial acetic acid, 2:7:1:0.1 (v/v/v/v) mobile phase. With the use of this system, a striking horizontal separation of betacyanin pigments is obtained for both the red beetroot juice and the commercial betanin sample (with the left-to-right resolution distance of the two bands equal to ca. 6 mm), and a unique pattern of the two skewed chromatographic bands is observed. This striking phenomenon has been given a thorough consideration, and its tentative physicochemical justification was provided, based on analogical cases reported and extensively discussed in our earlier studies. Characteristic fingerprint obtained both for the beetroot juice and the commercial sample of betanin (resembling two slant butterfly wings) can prove very helpful for qualitative confirmation of the presence (or otherwise) of the betanin pigment in the red color juices and beverages, as it was demonstrated upon an example of elderberry juice with a confirmed fortification with the betanin pigment.

Studies on the storage stability of fermented red dragon fruit (Hylocereus polyrhizus) drink

The objective of this work was to study the effect of storage temperatures and duration on the stability of fermented red dragon fruit drink (FRDFD) on its betacyanins content, physicochemical and microbiological qualities (BPM) and determining sensory acceptability. Results showed that both storage temperatures and duration have a significant effect on betacyanins content and physicochemical properties of FRDFD. Aerobic mesophilic and yeast and mold counts were lower than 1 × 103 CFU/mL for FRDFD stored at both temperatures. The loss of betanin (16.53-13.93 g/L) at 4 °C was 15.73% with no significant changes in physicochemical properties from week two onwards compared to 56.32% (16.53-7.22 g/L) of betanin loss at 25 °C. At week eight, FRDFD stored at 4 °C still contained 13.93 g/L betanin with a pH value of 3.46, suggested its potential as a functional drink which is sensory acceptable (mean score > 80% using hedonic test) among consumers.

Fast Extraction and Detection of 4-Methylimidazole in Soy Sauce Using Magnetic Molecularly Imprinted Polymer by HPLC

On the basis of magnetic molecularly imprinted polymer (MMIP) solid-phase extraction coupled with high performance liquid chromatography, we established a new method for the determination of the 4-methylimidazole (4-MEI) in soy sauce. Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM) were used to characterize the synthesized MMIPs. To evaluate the polymers, batch rebinding experiments were carried out. The binding strength and capacity were determined from the derived Freundlich isotherm (FI) equation. The selective recognition capability of MMIPs was investigated with a reference compound and a structurally similar compound. As a selective pre-concentration sorbents for 4-methylimidazole in soy sauce, the MMIPs showed a satisfied recoveries rate of spiked samples, ranged from 97% to 105%. As a result, the prepared MMIPs could be applied to selectively pre-concentrate and determine 4-methylimidazole in soy sauce samples.

Selective isolation of gonyautoxins 1,4 from the dinoflagellate Alexandrium minutum based on molecularly imprinted solid-phase extraction

Gonyautoxins 1,4 (GTX1,4) from Alexandrium minutum samples were isolated selectively and recognized specifically by an innovative and effective extraction procedure based on molecular imprinting technology. Novel molecularly imprinted polymer microspheres (MIPMs) were prepared by double-templated imprinting strategy using caffeine and pentoxifylline as dummy templates. The synthesized polymers displayed good affinity to GTX1,4 and were applied as sorbents. Further, an off-line molecularly imprinted solid-phase extraction (MISPE) protocol was optimized and an effective approach based on the MISPE coupled with HPLC-FLD was developed for selective isolation of GTX1,4 from the cultured A. minutum samples. The separation method showed good extraction efficiency (73.2-81.5%) for GTX1,4 and efficient removal of interferences matrices was also achieved after the MISPE process for the microalgal samples. The outcome demonstrated the superiority and great potential of the MISPE procedure for direct separation of GTX1,4 from marine microalgal extracts.

Novel molecularly imprinted polymer based on β-cyclodextrin@graphene oxide: Synthesis and application for selective diphenylamine determination

A sensitive and selective molecularly imprinted polymer (MIP) for the determination of diphenylamine (DPA) was developed based on host-guest interactions of a cyclodextrin-based polymer which possesses an inherent affinity for the target. The proposed GO@MIP has been prepared using the graphene oxide (GO) sheets as surface of polymerization, DPA as target molecule, β-cyclodextrin (β-CD) and acrylamide (AM) as functional monomers, azobisisobutyronitrile (AIBN) as initiator and N, N methylene bisacrylamide (MBAm) as crosslinker which denoted as GO@MIP nanocomposite. The MIP sites were formed by the inclusion complex through interaction of DPA and β-CD, followed by extraction of target. The resulting GO@MIP nanocomposite possess a fast adsorption kinetics, highly improved imprinting effect, high adsorption capacity, and it can be applied to fast extraction of DPA. The resultant GO@MIP nanocomposite was characterized using the Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS) analysis. On the other hand, the non-imprinted polymer (GO@NIP nanocomposite) has been synthesized and was used in the adsorption experiments. The MIP exhibited good affinity with a maximum adsorption capacity of 95.98mgg^-1 and excellent selectivity toward DPA than other structural analogues such as 2-amino benzophenone and dithizone.

The influence of variety on the content of bioactive compounds in beetroot (Beta vulgaris L.)

Vegetable are widespread throughout the world and is a major part of the human diet. From the perspective of agricultural crops that belong to the group of Beta vulgaris (beetroot, mangold, sugar beets, fodder beet) are first-rate vegetables. Especially popular is used in the food industry for the production of sugar, various vegetable juices, coloring agents, and many other products. Beetroot (Beta vulgaris L.) is considered one of the ten most important vegetable in the world, thanks to the content of rare natural pigments (betalains), polyphenols, flavonoids, antioxidants, vitamins, minerals and fiber. In this work we evaluated content of bioactive substances, especially the content of total polyphenols, anthocyanins and antioxidant activity in several varieties (Cylindra, Kahira, Chioggia, Crosby Egyptian) of beetroot (Beta vulgaris L.). Samples of plant material were collected at full maturity stages from areas of Zeleneč (Czech Republic). Zeleneč is area without negative influences and emission sources. Samples of fresh beetroot (Beta vulgaris L.) were homogenized and were prepared as an extract: 50 g cut beetroot (Beta vulgaris L.) extracted by 100 mL 80% ethanol for sixteen hours. These extracts were used for analyses. The content of the total polyphenols was determined by using the Folin-Ciocalteu reagent (FCR). The absorbance was measured at 765 nm of wavelength against blank. The content of total anthocyanins was measured at 520 nm wavelength of the blank. Antioxidant activity was measured using a compound DPPH˙ (2.2-diphenyl-1-picrylhydrazyl) at 515.6 nm in the spectrophotometer. In the present experiment it was detected, that total polyphenols content in samples ranges from 218.00 mg.kg-1 to 887.75 mg.kg-1, total anthocyanins content in samples ranges from 14.48 ±0.40 mg.kg-1 to 84.50 ±4.71 mg.kg-1 and values of antioxidant activity were in interval from 8.37 ±0.29% to 21.83 ±0.35%.