Microwave-assisted extraction of betalains from red beet (Beta vulgaris)

Enhancing the accuracy, speed, and efficiency of kafirin-PEO electrospun bio-nanocomposite pH indicators with red beetroot extract using image processing

Intelligent electrospun pH indicators were produced from bio-nanocomposite kafirin-polyethylene oxide (PEO) containing red beetroot extract. The aim was to evaluate the performance and stability of the electrospun pH indicators via image processing. Red beetroot extract was added to a mixture of kafirin and PEO at various concentrations. The mixtures were electrospun, and infrared Fourier transform spectroscopy confirmed the presence of kafirin, PEO, and red beetroot extract in the resulting pH indicator. The results showed that the pH indicators had high stability and reversibility at different temperatures, pHs, and environmental conditions. The results showed that the color of the indicators was significantly reversible after pH changes, with highly desirable reversibility observed at pH values of 1, 3, 4, 5, 7, 9, and 10. The findings proved that the red beetroot extract loaded bio-nanocomposite pH indicator accompanied by evaluation of color characteristics through image processing technique, can serve as a time-efficient, accurate tool for detecting and tracking pH changes caused by food spoilage.

Natural colour extraction from horticultural crops, advancements, and applications-a review

The scope for natural colours is increasing because of the awareness of allergic, toxic, and hazardous reactions associated with synthetic dyes. Natural colours are extracted from sources that are naturally available, such as flora, fauna, and minerals. Nature sourced us multiple possibilities of colours with varied shades and hues that are subtle and harmonious when combined. Reasons like the instability of natural colours during industrial processing, seasonal availability of raw materials, fading of colour over time, cost of the benefit, and struggles in attaining sustainability have reduced commercialisation success as synthetic colours. Some plants that yield natural colours are also included in crop rotation practice. Natural dye extraction is a source of employment for the countrified subdivisions of poor developing countries. Indigenous technologies on natural colour extraction are available and have been practiced over the years; due to a lack of documentation and information on colour-yielding plants or products from horticultural crops, and their extraction methods, the use of natural colours is diminishing day by day. Even in recent years, emerging techniques have been adopted in research and development, and the information has not been brought together for the use of industries and allied sectors. Several modern approaches, such as Ultrasonication, microwave, enzymatic, supercritical, pressurised liquid extraction, etc., have proven to give better results in extracting natural colours. Thereby, having instantaneous information will help to go green, be eco-friendly, and effectively utilise all the resources without compromising industrial benefits. Reviewing the availability of natural colours from horticultural crops, classifications, recent trends in their extraction process, and applications in various fields will help achieve the above.

Combining Conventional Organic Solvent Extraction, Ultrasound-Assisted Extraction, and Chromatographic Techniques to Obtain Pure Betanin from Beetroot for Clinical Purposes

Red beetroot extract (E162) is a natural colorant that owes its color to betanin, its major red pigment. Betanin displays remarkable antioxidant, anti-inflammatory, and chemoprotective properties mediated by its structure and influence on gene expression. However, the betanin employed in most preclinical assays is a beetroot extract diluted in dextrin, not pure betanin, as no isolated compound is commercially available. This makes its use inaccurate concerning product content estimates and biological effect assessments. Herein, a combination of conventional extraction under orbital shaking and ultrasound-assisted extraction (UAE) to purify betanin by semi-preparative HPLC was performed. The employed methodology extracts betalains at over a 90% yield, achieving 1.74 ± 0.01 mg of pure betanin/g beetroot, a 41% yield from beetroot contents increasing to 50 %, considering the betalains pool. The purified betanin exhibited an 85% purity degree against 32 or 72% of a commercial standard evaluated by LC-MS or HPLC methods, respectively. The identity of purified betanin was confirmed by UV-Vis, LC-MS, and 1H NMR. The combination of a conventional extraction, UAE, and semi-preparative HPLC allowed for betanin purification with a high yield, superior purity, and almost three times more antioxidant power compared to commercial betanin, being, therefore, more suitable for clinical purposes.

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.

Synthesis and Antioxidative Properties of 1,2,3,4-Tetrahydropyridine Derivatives with Different Substituents in 4-Position

Natural products are an excellent source of inspiration for the development of new drugs. Among them, betalains have been extensively studied for their antioxidant properties and potential application as natural food dyes. Herein, we describe the seven-step synthesis of new betalamic acid analogs without carboxy groups in the 2- and 6-position with an overall yield of ~70%. The Folin–Ciocalteu assay was used to determine the antioxidant properties of protected intermediate 21. Additionally, the five-step synthesis of betalamic acid analog 35 with three ester moieties was performed. Using NMR techniques, the stability of the obtained compounds towards oxygen was analyzed.

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

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Several fruits, plants, and roots are sources of betalains.

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Betalains analysis can be performed by spectroscopic and chromatographic methods.

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Betalains extraction techniques have advantages and disadvantages.

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Betalains encapsulation increases its stability and possibility of incorporation in foods.

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The incorporation of betalains in food packaging is a potential application.

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

Yogurt fortification by microencapsulation of beetroot extract (Beta vulgaris L.) using maltodextrin, gum arabic, and whey protein isolate

The effect of three different coating materials, including maltodextrin (MD, 9.95-20.05%), gum arabic (GA, 4.98-10.02%), and whey protein isolate (WPI, 4.95-15.05%), was optimized in order to produce high-quality beetroot extract powder (BEP) using response surface modeling (RSM). Beetroot extract (BE) was encapsulated using MD, GA, and WPI by implementing a spray-drying method. The highest total phenolic content (TPC) was obtained at 15% MD, 7.5% GA, and 10% WPI. The same results were achieved for antioxidant activity. Increasing the MD and GA contents resulted in reducing the moisture adsorption of microencapsulated BEP.

Green Techniques for Preparation of Red Beetroot Extracts with Enhanced Biological Potential

Red beetroot is well known for its high proportion of betalains, with great potential as functional food ingredients due to their health-promoting properties. The objective of this study was to investigate the influence of processing techniques such as Soxhlet, cold, ultrasound and supercritical fluid extraction on the betalains content and its antioxidant, anti-inflammatory and antihyperglycemic activities. Whilst Soxhlet extraction with water has provided the highest yield, the highest content of total phenolics was found in an extract prepared using Soxhlet extraction with 50% ethanol. Amongst eight phenolic compounds detected in the extracts, protocatechuic acid was the most abundant. The concentrations of total phenolics ranged from 12.09 mg/g (ultrasound extraction with 30% methanol) to 18.60 mg/g (Soxhlet extraction with 50% ethanol). The highest anti-inflammatory activity was observed for cold extraction with 50% methanol extract. The high radical scavenging activity of supercritical fluid extracts could be a consequence of nonphenolic compounds. The chemometrics approach was further used to analyse the results to find the “greenest” method for further possible application in the processing of beetroot in the food and/or pharmaceutical industry. According to the standard score, the best extraction method was determined to be Soxhlet extraction with 50% ethanol.

Biotechnological advances for improving natural pigment production: a state-of-the-art review

In current years, natural pigments are facing a fast-growing global market due to the increase of people's awareness of health and the discovery of novel pharmacological effects of various natural pigments, e.g., carotenoids, flavonoids, and curcuminoids. However, the traditional production approaches are source-dependent and generally subject to the low contents of target pigment compounds. In order to scale-up industrial production, many efforts have been devoted to increasing pigment production from natural producers, via development of both in vitro plant cell/tissue culture systems, as well as optimization of microbial cultivation approaches. Moreover, synthetic biology has opened the door for heterologous biosynthesis of pigments via design and re-construction of novel biological modules as well as biological systems in bio-platforms. In this review, the innovative methods and strategies for optimization and engineering of both native and heterologous producers of natural pigments are comprehensively summarized. Current progress in the production of several representative high-value natural pigments is also presented; and the remaining challenges and future perspectives are discussed.

Betalain plant sources, biosynthesis, extraction, stability enhancement methods, bioactivity, and applications

Betalains are plant pigments with functional properties used mainly as food dyes. However, they have been shown to be unstable to different environmental factors. This paper provides a review of (1) Betalain plant sources within several plant families such as Amaranthaceae, Basellaceae, Cactaceae, Portulacaceae, and Nyctaginaceae, (2) The biosynthesis pathway of betalains for both betacyanins and betaxanthins, (3) Betalain extraction process, including non-conventional technologies like microwave-assisted, ultrasound-assisted, and pulsed electrical field extraction, (4) Factors affecting their stability, mainly temperature, water activity, light incidence, as well as oxygen concentration, metals, and the presence of antioxidants, as well as activation energy as a mean to assess stability, and novel food-processing technologies able to prevent betalain degradation, (5) Methods to increase shelf life, mainly encapsulation by spray drying, freeze-drying, double emulsions, ionic gelation, nanoliposomes, hydrogels, co-crystallization, and unexplored methods such as complex coacervation and electrospraying, (6) Biological properties of betalains such as their antioxidant, hepatoprotective, antitumoral, and anti-inflammatory activities, among others, and (7) Applications in foods and other products such as cosmetics, textiles and solar cells, among others. Additionally, study perspectives for further research are provided for each section.

Bioactive Betalain Extracts from Cactus Pear Fruit Pulp, Beetroot Tubers, and Amaranth Leaves

Natural food items and the additional benefits they provide have received considerable attention in recent years. Betalains are nutritious pigments which have valuable biological properties, e.g., antioxidant and free radical scavenging activity. In this study, aqueous betalain extracts were obtained from different coloured cactus pears (purple, red/pink, and orange), amaranth, and beetroot, with and without the addition of ascorbic acid, microwave-heated, and freeze-dried and subsequently analysed by thin layer chromatography (TLC). Beetroot samples without the addition of ascorbic acid (AA) had lower phenols, flavonoids, and ascorbic acid content than beetroot samples extracted with the addition of AA. Amaranth had significantly higher contents of antioxidants than all the other plants. Results for phenolic compounds showed that there were no significant differences between cactus pear cultivars, however, significant differences were seen between the two beetroot samples (microwave-heated with and without AA) as well as amaranth. For flavonoid compounds, amaranth had significantly higher values than all other samples. The lowest flavonoid content was found in beetroot without AA (0.49 mgCE/g). For ascorbic acid, significant differences were noticed between amaranth (71.71 mg/100 g) and samples from cactus pear and beetroot. TLC results showed that purple and red cactus pear samples had the most vivid colours, a reflection of the high betacyanin and betaxanthin contents in the cultivars. Moreover, extracts from cactus pear, beetroot, and amaranth were classified according to a decision tree which was designed by the Code of Federal Regulations/Food Additives Regulation of the EU. The classification of betalain pigment extracts as colouring foods was achieved through enrichment factor calculations and the colourant decision tree. The results showed that the betalain pigment extraction method used is inexpensive, time-saving, energy-saving, non-toxic, and chemical solvent free and yields high concentrations of betalains.

Valorization of natural colors as health-promoting bioactive compounds: Phytochemical profile, extraction techniques, and pharmacological perspectives

Color is the prime attribute with a large impact on consumers' perception, selection, and acceptance of foods. However, the belief in bio-safety protocols, health benefits, and the nutritional importance of food colors had focused the attention of the scientific community across the globe towards natural colorants that serve to replace their synthetic toxic counterparts. Moreover, multi-disciplinary applications of greener extraction techniques and their hyphenated counterparts for selective extraction of bioactive compounds is a hot topic focusing on process intensification, waste valorization, and retention of highly stable bioactive pigments from natural sources. In this article, we have reviewed available literature to provide all possible information on various aspects of natural colorants, including their sources, photochemistry and associated biological activities explored under in-vitro and in-vivo animal and human studies. However a particular focus is given on innovative technological approaches for the effective extraction of natural colors for nutraceutical and pharmaceutical applications.

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.

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.

Optimization of ultrasound-assisted extraction of bioactive compounds from acerola waste

The industrial processing of acerola (Malpighia emarginata D.C.) produces huge quantities of waste material that are badly discarded or undervalued. In spite of this, acerola wastes have a high content of antioxidant compounds. The aim of this work was to study the extraction of antioxidant compounds from acerola residues using ultrasound assisted extraction. Using multiple regression techniques, the effects of ethanol concentration in the hydroethanolic solution (C), extraction time (t), temperature (T), and liquid-solid ratio (R) on the total phenolic content, total flavonoid content and antioxidant potential were investigated. The best extraction conditions were identified using the desirability function, which is a multi-response optimization technique. The optimal processing parameters were 67.5% of ethanol concentration, temperature of 80.9 °C, liquid/solid ratio of 59.8 mL/g, and extraction time of 13.6 min. HPLC-UV has been used to identify the main antioxidant compounds obtained under these optimal condition. Based on the results, acerola waste has high potential for better use, such as in food and pharmaceutical applications.

Red Beetroot Betalains: Perspectives on Extraction, Processing, and Potential Health Benefits

In recent years, red beetroot has received a growing interest due to its abundant source of bioactive compounds, particularly betalains. Red beetroot betalains have great potential as a functional food ingredient employed in the food and medical industry due to their diverse health-promoting effects. Betalains from red beetroot are natural pigments, which mainly include either yellow-orange betaxanthins or red-violet betacyanins. However, betalains are quite sensitive toward heat, pH, light, and oxygen, which leads to the poor stability during processing and storage. Therefore, it is necessary to comprehend the impacts of the processing approaches on betalains. In this review, the effective extraction and processing methods of betalains from red beetroot were emphatically reviewed. Furthermore, a variety of recently reported bioactivities of beetroot betalains were also summarized. The present work can provide a comprehensive review on both conventional and innovative extraction techniques, processing methods, and the stability of betalains.

Recovery of Phytochemicals via Electromagnetic Irradiation (Microwave-Assisted-Extraction): Betalain and Phenolic Compounds in Perspective

Food colorants processed via agro-industrial wastes are in demand as food waste management becomes vital not only for its health benefits but also for cost reduction through waste valorization. Huge efforts have been made to recover valuable components from food wastes and applied in various fields to prove their versatility rather than for feed ruminant usage only. Betalains and phenolics, antioxidant-rich compounds responsible for host color and so commonly used as natural colorants in food and cosmetic industries, are copiously present in several kinds of fruits and vegetables as well as their wastes. Technological innovation has brought extensive convenient ways of bioactive compounds extraction with many advantages like less use of solvents and energy in a short period of processing time in comparison with the classical solid–liquid extraction methods. Emerging technologies, particularly microwave irradiation, have been amenable to electromagnetic technology for decades. Practically, they have been deployed for functional and supplement food production. In this review, the feasibility of dielectric heating (microwave irradiation) in the extraction of betalain and phenolic compounds mostly from fruit and vegetable wastes was discussed.

Sustainable Micro-Scale Extraction of Bioactive Phenolic Compounds from Vitis vinifera Leaves with Ionic Liquid-Based Surfactants

This paper proposes a new sustainable and simple strategy for the micro-scale extraction of phenolic compounds from grapevine leaves with analytical purpose. The method is based on a microwave-assisted solid-liquid extraction approach (MA-SLE), using an aqueous solution of an ionic liquid (IL)-based surfactant as extraction phase. The method does not require organic solvents, nor any clean-up step, apart from filtration prior to the injection in the analytical system. Two IL-based surfactants were evaluated, and the method was optimized by using experimental designs, resulting in the use of small amounts of sample (100 mg) and extraction phase (2.25 mL), low concentrations of the selected 1-hexadecyl-3-butyl imidazolium bromide IL (0.1 mM), and 30 min of extraction time. The proposed methodology was applied for the determination of the polyphenolic pattern of six different varieties of Vitis vinifera leaves from the Canary Islands, using high-performance liquid chromatography and photodiode array detection for the quantification of the compounds. The proposed MA-SLE approach was greener, simpler, and more effective than other methods, while the results from the analysis of the leaves samples demonstrate that these by-products can be exploited as a source of natural compounds for many applications.

Valorization of Banana and Red Beetroot Peels: Determination of Basic Macrocomponent Composition, Application of Novel Extraction Methodology and Assessment of Biological Activity In Vitro

The nutritional and bioactive content of banana and red beetroot peels was investigated. The basic macrocomponent composition was determined using standard AOAC (Association of Official Analytical Chemists) methods, while the recovery efficiency of bioactive compounds was investigated using conventional and innovative extraction techniques (subcritical water extraction, ultrasound- and microwave-assisted extraction). Extracts were analyzed for biological effects in vitro on human hepatic, tongue and colon cancer cell lines. A macrocomponent analysis revealed a notable amount of dietary fiber in banana and beetroot peels (39.0 and 33.6% dmb) and a relatively high content of protein in beetroot peel (18.3% dmb). Regarding the micronutrients-minerals, banana and beetroot peels were shown to be a very good source of potassium (75.06 and 41.86 mg g−1 dmb). Both extracts of banana and beetroot peels obtained by conventional extraction - decoction (100 °C, 20 min) exhibited the highest total phenolic content and antioxidant capacity. Additionally, in banana peel, these extracts were the richest in dopamine content (12.63 mg g−1 dmb). Extraction by infusion (80 °C, 30 min) yielded a beetroot peel extract with the highest total betacyanin content (9.80 mg g−1 dmb). Biological effects in vitro were dose- and time-dependent, as well as influenced by the presence of polysaccharides.

Red beet extract usage in gelatin/gellan based gummy candy formulation introducing Salix aegyptiaca distillate as a flavouring agent

Nowadays, the functionalization of food products using natural health-promoting additives is of great interest. Betalains are the natural pigments of red beets and are known for their health-promoting characteristics. The aim of this study was to evaluate gummy candies formulated with red beet extract (0.1 or 0.3%) as the coloring agent, Salix aegyptiaca distillate as the flavoring agent, and gellan gum (0.5 or 1.5%) as the gelling co-agent. The prepared gummy candy samples were assessed via texture profile analysis, DPPH assay, sensory evaluation, and color analysis. The results revealed that hardness (~ 60 N) improved and gumminess (~ 15 N) decreased with an increment in gellan gum content in the gummy candy formulation. Statistical analysis indicated that by addition of red beet extract, the radical scavenging capacity of the samples increased (50%) significantly (p < 0.05). Furthermore, gellan gum usage lead to the generation of a glossy red color and enhanced the lightness of the samples in comparison with gelatin-based gummy candies. About sensory evaluation, the panelists confirmed that usage of Salix aegyptiaca improved the sensory characteristics of the gummy candy (overall acceptance from 7.4 to 8.2; out of 9). Our findings suggest that gellan gum (as a highly transparent, acid-resistant, gel-forming gum), red beet extract (as an acid-stabilized natural color), and Salix aegyptiaca distillate have immense potential in the food industry for use as structuring, coloring, and flavoring agents, respectively.

Ultrasound and Microwave Assisted Extraction of Opuntia Fruit Peels Biocompounds: Optimization and Comparison Using RSM-CCD

Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) of bioactive compounds, peels from Opuntia engelmannii cultivar (cv.) Valencia were optimized by response surface methodology. Randomized extraction runs were performed for each of the technologies employed in order to build effective models with maximum (bioactive molecules content and yield) and minimum (antioxidant activity) responses. A 5-level, 4-factor central composite design was used to obtain target responses as a function of extraction time (t), solid to liquid ratio (S/L), methanol concentration (metOH), and temperature (T). Specific response optimization for each technology was analyzed, discussed, and general optimization from all the responses together was also gather. The optimum values for each factor were: t = 2.5 and 1.4 min, S/L = 5 and 5 g/L, metOH = 34.6 and 0% of methanol and T = 30 and 36.6 °C, achieving maximum responses of 201.6 and 132.9 mg of betalains/g, 13.9 and 8.0 mg of phenolic acids/g, 2.4 and 1.5 mg of flavonoids/g, 71.8% and 79.1% of extractable solid and IC₅₀ values for the antioxidant activity of 2.9 and 3.6, for UAE and MAE, respectively. The present study suggested UAE as the best extraction system, in order to maximize recovery of bioactive compounds with a high antioxidant activity.

The Impact of Pulsed Electric Field on the Extraction of Bioactive Compounds from Beetroot

Beetroot is a root vegetable rich in different bioactive components, such as vitamins, minerals, phenolics, carotenoids, nitrate, ascorbic acids, and betalains, that can have a positive effect on human health. The aim of this work was to study the influence of the pulsed electric field (PEF) at different electric field strengths (4.38 and 6.25 kV/cm), pulse number 10–30, and energy input 0–12.5 kJ/kg as a pretreatment method on the extraction of betalains from beetroot. The obtained results showed that the application of PEF pre-treatment significantly (p < 0.05) influenced the efficiency of extraction of bioactive compounds from beetroot. The highest increase in the content of betalain compounds in the red beet’s extract (betanin by 329%, vulgaxanthin by 244%, compared to the control sample), was noted for 20 pulses of electric field at 4.38 kV/cm of strength. Treatment of the plant material with a PEF also resulted in an increase in the electrical conductivity compared to the non-treated sample due to the increase in cell membrane permeability, which was associated with leakage of substances able to conduct electricity, including mineral salts, into the intercellular space.

Extraction of red beet extract with β-cyclodextrin-enhanced ultrasound assisted extraction: A strategy for enhancing the extraction efficacy of bioactive compounds and their stability in food models

Improving the extraction efficiency and stability of red beet compounds has gained the attention of researchers due to their high nutritional and health benefits. In this study, β-cyclodextrin (β-CD) enhanced ultrasound assisted extraction was used for the extraction of red beet extract, and lyophilized extracts were characterized with FTIR and DSC analyses. The samples extracted with aqueous 5% β-CD solutions revealed the highest content of betanin (2.243 ± 0.04 mg) and total phenolic compounds (20.03 ± 1.28 mg GAE/g DW), and the highest DPPH inhibition activity (59.87 ± 4.94%). Additionally, complexation with β-CD significantly enhanced the stability of betanin, phenolic compounds and antiradical activity in the stored beverage and gummy candy models at various pH and temperature conditions during 28 days. In conclusion, β-CD-enhanced ultrasound assisted extraction is a suitable approach to extracting and stabilizing the red beet compounds for application in food, nutraceutical, and medical fields.

Conical intersections and the weak fluorescence of betalains

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

Betalains in Some Species of the Amaranthaceae Family: A Review

Natural pigments are largely distributed in the plant kingdom. They belong to diverse groups, with distinct biochemical pathways. Betalains with colours that range from yellow to red-violet can de divided into two main subgroups: betaxanthins and betacyanins. These types of pigments are confined into 13 families of the order Caryophyllales and in some genera of higher fungi (Amanita muscaria, Hygrocybe and Hygrophorus). The Amaranthaceae family includes diverse genera in which betalains are present: Alternanthera, Amaranthus, Beta, Chenopodium, Celosia and Gomphrena. The biosynthesis of betalains and their general biological properties were reviwed in the present work. In addition, the types of betalains present in some species of the aforementioned genera, their stability and production, as well as biological attributes, were reviewed.

Beet and orange mixed juices added with Lactobacillus acidophilus

Purpose

The purpose of this study was to evaluate beet and orange mixed juices added with lyophilized Lactobacillus acidophilus probiotic culture.

Design/methodology/approach

Two formulations of probiotic beet and orange mixed juices (1:1 e 1:2 v/v) were prepared, stored at 4°C for 28 days and were evaluated for probiotic survival, physicochemical stability, antioxidant activity and sensory acceptance. The probiotic culture was added in a lyophilized form and was not propagated in culture media or juice.

Findings

Physicochemical characteristics (pH, titratable acidity, total soluble solids and color) and antioxidant activity showed no undesirable alterations during storage. The number of probiotics followed established minimum requirement for probiotic foods (109 CFU/200mL) during the 28 days of storage. The juices showed good sensory acceptance and purchase intention, especially regarding the color of the product.

Practical implications

The beet and orange mixed juices are suitable carriers for L. acidophilus with a shelf life of at least 28 days at 4°C.

Originality/value

Direct addition of the probiotic culture could result in high probiotic survival in mixed juices, dispensing the propagation step.

Natural colorants: Pigment stability and extraction yield enhancement via utilization of appropriate pretreatment and extraction methods

Natural colorants from plant-based materials have gained increasing popularity due to health consciousness of consumers. Among the many steps involved in the production of natural colorants, pigment extraction is one of the most important. Soxhlet extraction, maceration, and hydrodistillation are conventional methods that have been widely used in industry and laboratory for such a purpose. Recently, various non-conventional methods, such as supercritical fluid extraction, pressurized liquid extraction, microwave-assisted extraction, ultrasound-assisted extraction, pulsed-electric field extraction, and enzyme-assisted extraction have emerged as alternatives to conventional methods due to the advantages of the former in terms of smaller solvent consumption, shorter extraction time, and more environment-friendliness. Prior to the extraction step, pretreatment of plant materials to enhance the stability of natural pigments is another important step that must be carefully taken care of. In this paper, a comprehensive review of appropriate pretreatment and extraction methods for chlorophylls, carotenoids, betalains, and anthocyanins, which are major classes of plant pigments, is provided by using pigment stability and extraction yield as assessment criteria.

Microwave processing: Effects and impacts on food components

As an efficient heating method, microwave processing has attracted attention both in academic research and industry. However, the mechanism of dielectric heating is quite distinct from that of the traditional conduction heating, and is widely applied as polar molecules and charged ions interaction with the alternative electromagnetic fields, resulting in fast and volumetric heating through their friction losses. Such a heating pattern would cause a certain change in microwave treatment, which is an unarguable reality. In this review, we made a retrospect of the essential knowledge about dielectric properties and summarized the concept of microwave heating, and the impact of microwave application on the main components of foods and agricultural products, which are classified as carbohydrates, lipids, proteins, chromatic/flavor substances, and vitamins. Finally, we offered a way to resolve the drawbacks of relevant microwave treatment and outlined the directions for future research.

Coloring attributes of betalains: a key emphasis on stability and future applications

Organoleptic characteristics largely determine food acceptance, selection, and subsequent consumption.

Impact of extraction and processing conditions on betalains and comparison of properties with anthocyanins - A current review

The search for natural pigments has been driven by growing evidence indicating that synthetic colorants can cause deleterious health effects. Betalains, in addition to anthocyanins, have been proposed as an alternative to address this need. However, the incorporation of natural pigments poses some challenges to the food industry, such as reduced stability in comparison to their synthetic counterparts. Moreover, betalains are not well studied in comparison to anthocyanins and information about the effects of processing on their physicochemical properties and stability is scattered. Thus, this review will provide an overview of the recent research on the extraction and processing of betalains from natural sources, and comparison of their colorant and physicochemical properties with anthocyanins.