Ultrasound assisted enhancement in natural dye extraction from beetroot for industrial applications and natural dyeing of leather

Combinatorial engineering of betalain biosynthesis pathway in yeast Saccharomyces cerevisiae

BACKGROUND

Betalains, comprising red-violet betacyanins and yellow-orange betaxanthins, are the hydrophilic vacuolar pigments that provide bright coloration to roots, fruits, and flowers of plants of the Caryophyllales order. Betanin extracted from red beets is permitted quantum satis as a natural red food colorant (E162). Due to antioxidant activity, betanin has potential health benefits.

RESULTS

We applied combinatorial engineering to find the optimal combination of a dozen tyrosine hydroxylase (TyH) and 4,5-dopa-estradiol-dioxygenase (DOD) variants. The best-engineered Saccharomyces cerevisiae strains produced over six-fold higher betaxanthins than previously reported. By genome-resequencing of these strains, we found out that two copies of DOD enzyme from Bougainvillea glabra together with TyH enzymes from Abronia nealleyi, Acleisanthes obtusa, and Cleretum bellidiforme were present in the three high-betaxanthin-producing isolates. Next, we expressed four variants of glucosyltransferases from Beta vulgaris for betanin biosynthesis. The highest titer of betanin (30.8 ± 0.14 mg/L after 48 h from 20 g/L glucose) was obtained when completing the biosynthesis pathway with UGT73A36 glucosyltransferase from Beta vulgaris. Finally, we investigated betalain transport in CEN.PK and S288C strains of Saccharomyces cerevisiae and identified a possible role of transporter genes QDR2 and APL1 in betanin transport.

CONCLUSIONS

This study shows the potential of combinatorial engineering of yeast cell factories for the biotechnological production of betanin.

An eco-friendly ultrasound approach to extracting yellow dye from Cassia alata flower petals: Characterization, dyeing, and antibacterial properties

Using natural dyes in dyeing industries becomes an alternative to synthetic dyes, which are known to contain harmful chemicals that can pose risks to the environment and human health. This study involves the extraction of yellow dye from Cassia alata flower petals, optimization of the extraction process using an ultrasonic bath (40 KHz and an input power of 500), ultrasonic probe (390 W, 455 W, 520 W, 585 W, and 650 W), and conventional heating (heating mantle with 30 °C, 40 °C, 50 °C, 60 °C, and 70 °C), characterization of the dye, as well as dyeing (cotton, silk, and leather) without using a mordant. The extracted yellow dye was further evaluated to determine its antibacterial activity against skin bacteria. Dye extraction optimization using UV-Visible spectrophotometric analysis revealed that the maximum yellow color in methanol extract (287 and 479 nm) was obtained at 50 °C for 45 min using ultrasonic water bath extraction, followed by the ultrasonic probe and direct heating. Based on the FTIR spectra, it is evident that OH is present at approximately 3300 cm^-1, while CH stretches at around 2900 cm^-1. A characteristic peak at 1608 cm^-1 bears a striking similarity to anthraquinonoid-based compounds. Also, using the ultrasonic water bath dyeing technique at 50 °C for 45 min, the yellow color of cotton, silk, and leather was dyed optimally. Due to effective color removal after two washings with boiling soap liquid, the dyed cotton and silk fabric displayed good washing and rubbing fastness. Regarding antibacterial activity, the dye was highly active against all pathogens after extraction in methanol. The maximum inhibition was observed against Pseudomonas sp. with a MIC value of 1.56 mg/ml.

A Review on Photocatalysis Used For Wastewater Treatment: Dye Degradation

Water pollution is a global issue as a consequence of rapid industrialization and urbanization. Organic compounds which are generated from various industries produce problematic pollutants in water. Recently, metal oxide (TiO2, SnO2, CeO2, ZrO2, WO3, and ZnO)-based semiconductors have been explored as excellent photocatalysts in order to degrade organic pollutants in wastewater. However, their photocatalytic performance is limited due to their high band gap (UV range) and recombination time of photogenerated electron-hole pairs. Strategies for improving the performance of these metal oxides in the fields of photocatalysis are discussed. To improve their photocatalytic activity, researchers have investigated the concept of doping, formation of nanocomposites and core-shell nanostructures of metal oxides. Rare-earth doped metal oxides have the advantage of interacting with functional groups quickly because of the 4f empty orbitals. More precisely, in this review, in-depth procedures for synthesizing rare earth doped metal oxides and nonocomposites, their efficiency towards organic pollutants degradation and sources have been discussed. The major goal of this review article is to propose high-performing, cost-effective combined tactics with prospective benefits for future industrial applications solutions.

A review of plant-based natural dyes in leather application with a special focus on color fastness characteristics

Dyes/colorants are normally used to improve the aesthetic of consumer products, and leather is one of them. The leather industry plays a significant role in the global economy. However, the leather-making process causes severe environmental pollution. Synthetic dyes are one of the major classes of leather chemicals that are responsible for the enhanced pollution load created by the industry. Over the years, excessive use of synthetic dyes in consumer products created severe environmental pollution and health hazard. Many of these synthetic dyes are carcinogenic, allergic, cause serious health problems for human beings, and have been restricted by regulatory authorities for use in consumer goods. Since ancient days, natural dyes and colorants have been used to make lives colorful. Amid the green movements and environment-friendly products/processes, natural dyes are back to mainstream fashion. Moreover, natural colorants have become a trend due to their eco-friendly nature. The demand for non-toxic and eco-friendly dyes and pigments is increasing. However, the question remains "is natural dyeing sustainable" or "how to make it sustainable." Here, we review the literature reports on natural dye's application in leather in the last two decades. This review article provides a detailed overview and current knowledge base on the various plant-based natural dyes used in leather dyeing, their fastness properties, and the need of the hour in terms of product and process development to make natural dying sustainable. The color fastness characteristics of the dyed leather to light, rub, and perspiration have been critically discussed.

Development of an Ultrasonic-Assisted Extraction Technique for the Extraction of Natural Coloring Substance Chlorophyll from Leaves of Carica papaya

Beautiful green leaves of Papaya are the rich source of Chlorophyll. Green color of chlorophyll has been used for a very long time as a natural colorant. Carica papaya has been considered as a good example and reasonable source of natural phytochemicals, which makes it suitable to color the food items and beverages. The aim of the present investigation is to develop the process of ultrasonic extraction in combination with solid phase extraction (SPE) to extract out chlorophyll with high yield as well as high degree of clarity. Newly customized ultrasonic-assisted extraction technique for the extraction of chlorophyll from Carica papaya leaves is optimized by taking different parameters like time, temperature, solvents concentrations, and raw material under consideration. Furthermore, the extract was purified by means of SPE and examined by using UV-Vis spectrophotometer. The highest yield of chlorophyll (dye) extract was found as 40% in solvent solution having 80 mL of ethanol and 20 mL of water with 5 minutes of extraction time, 35°C of temperature, and 1 grams of raw material in the sonication bath. Furthermore, the SPE purified sample was characterized by means of the UV-Vis spectrophotometer and here the total chlorophyll content was 34 mg/g, including chlorophyll a with a concentration of 14.1246 mg/g and chlorophyll b with concentration of 19.845 mg/g respectively. Consequently, sonication method can be suggested as a good method to get better concentration of chlorophyll.

Effect of nonthermal treatments on selected natural food pigments and color changes in plant material

In recent years, traditional high-temperature food processing is continuously being replaced by nonthermal processes. Nonthermal processes have a positive effect on food quality, including color and maintaining natural food pigments. Thus, this article describes the influence of nonthermal, new, and traditional treatments on natural food pigments and color changes in plant materials. Characteristics of natural pigments, such as anthocyanins, betalains, carotenoids, chlorophylls, and so forth available in the plant tissue, are shortly presented. Also, the characteristics and mechanism of nonthermal processes such as pulsed electric field, ultrasound, high hydrostatic pressure, pulsed light, cold plasma, supercritical fluid extraction, and lactic acid fermentation are described. Furthermore, the disadvantages of these processes are mentioned. Each treatment is evaluated in terms of its effects on all types of natural food pigments, and the possible applications are discussed. Analysis of the latest literature showed that the use of nonthermal technologies resulted in better preservation of pigments contained in the plant tissue and improved yield of extraction. However, it is important to select the appropriate processing parameters and to optimize this process in relation to a specific type of raw material.

Recent Advances in Recovery of Lycopene from Tomato Waste: A Potent Antioxidant with Endless Benefits

Growing attention to environmental protection leads food industries to adopt a model of "circular economy" applying safe and sustainable technologies to recover, recycle and valorize by-products. Therefore, by-products become raw material for other industries. Tomato processing industry produces significant amounts of by-products, consisting of skins and seeds. Tomato skin is very rich in lycopene, and from its seeds, high nutritional oil can be extracted. Alternative use of the two fractions not only could cut disposal costs but also allow one to extract bioactive compounds and an oil with a high nutritional value. This review focused on the recent advance in extraction of lycopene, whose beneficial effects on health are widely recognized.

The Influence of Different Pretreatment Methods on Color and Pigment Change in Beetroot Products

Vegetable processing pomace contains valuable substances such as natural colors that can be reused as functional ingredients. Due to a large amount of water, they are an unstable material. The aim of our research was to assess how the pretreatment method (thermal or nonthermal) affects the properties of powders obtained from beet juice and pomace after the freeze-drying process. The raw material was steamed or sonicated for 10 or 15 min, and then squeezed into juice and pomace. Both squeezed products were freeze-dried. The content of dry substance; L*, a*, and b* color parameters; and the content of betalain pigments were analyzed. Pretreatments increased the proportion of red and yellow in the juices. Steam and ultrasound caused a significant reduction in parameter b* in the dried pomace. A significant increase in betanin in lyophilizates was observed after pretreatment with ultrasound and steam for 15 min. As a result of all experiments, dried juices and pomaces can also be used as a colorant source. However, there is higher potential with pomaces due to their additional internal substances as well as better storage properties. After a few hours, juice was sticky and not ready to use.

Advanced Oxidation Processes and Biotechnological Alternatives for the Treatment of Tannery Wastewater

The tannery industry is one of the economic sectors that contributes to the development of different countries. Globally, Europe and Asia are the main producers of this industry, although Latin America and Africa have been growing considerably in recent years. With this growth, the negative environmental impacts towards different ecosystem resources as a result of the discharges of recalcitrated pollutants, have led to different investigations to generate alternative solutions. Worldwide, different technologies have been studied to address this problem, biological and physicochemical processes have been widely studied, presenting drawbacks with some recalcitrant compounds. This review provides a context on the different existing technologies for the treatment of tannery wastewater, analyzing the physicochemical composition of this liquid waste, the impact it generates on human health and ecosystems and the advances in the different existing technologies, focusing on advanced oxidation processes and the use of microalgae. The coupling of advanced oxidation processes with biological processes, mainly microalgae, is seen as a viable biotechnological strategy, not only for the removal of pollutants, but also to obtain value-added products with potential use in the biorefining of the biomass.

Biological Properties and Applications of Betalains

Betalains are water-soluble pigments present in vacuoles of plants of the order Caryophyllales and in mushrooms of the genera Amanita, Hygrocybe and Hygrophorus. Betalamic acid is a constituent of all betalains. The type of betalamic acid substituent determines the class of betalains. The betacyanins (reddish to violet) contain a cyclo-3,4-dihydroxyphenylalanine (cyclo-DOPA) residue while the betaxanthins (yellow to orange) contain different amino acid or amine residues. The most common betacyanin is betanin (Beetroot Red), present in red beets Beta vulgaris, which is a glucoside of betanidin. The structure of this comprehensive review is as follows: Occurrence of Betalains; Structure of Betalains; Spectroscopic and Fluorescent Properties; Stability; Antioxidant Activity; Bioavailability, Health Benefits; Betalains as Food Colorants; Food Safety of Betalains; Other Applications of Betalains; and Environmental Role and Fate of Betalains.

Intensification of bio-actives extraction from pomegranate peel using pulsed ultrasound: Effect of factors, correlation, optimization and antioxidant bioactivities

Pomegranate peel (PP) is one of the interesting agri-food by-products because of its abundant bioactive phytochemicals. However, the bioactivity of valuable compounds is affected due to the extraction method used. A pulsed ultrasound-assisted extraction (PUAE) was carried out to intensify the extraction efficacy with reduced power and time. Influence of several process variables viz. peel solids/ solvent ratio, sonication power, duty cycle, and extraction time was studied using empirical quadratic models followed by multicriterial numerical optimization with respect to face-centered composite design. Power-duty cycle combination was found to be most significant (p < 0.05) for process intensification. The optimal process conditions of 2.17 g/100 mL S/S ratio at 116 W power with 80% duty cycle for 6 min resulted into 0.48 g/g yield, 177.54 mg GAE/g total phenolics content, 35.71 mg QE/g total flavonoids, 160.54 mg GAE/g antioxidant capacity, 21.65 mg cyn-3-glc/100 g anthocyanin content with 54.92 browning index in dry pomegranate peel. Significant Pearson correlation analysis was established in all responses with potent phenols and flavonoid relation with highest coefficient (r) 0.931. All response models were significantly validated with regression coefficient (R2) above 0.965. Remarkable antioxidant bioactivities were recorded for the resultant peel extract. Hence, it is strongly recommended that PUAE could be successfully applied for the intensification of the extraction process of bioactive from any peel and or plant systems with minimal process time and power consumption with a green label.

Development of an aqueous ultrasound-assisted extraction process of bioactive compounds from beet leaves: a proposal for reducing losses and increasing biomass utilization

BACKGROUND

Red beet plants are cultivated worldwide for the consumption of their roots, generating large amounts of unexploited by-products. In particular, beet leaves (BLs) represent about 50% of the whole plant and are usually discarded as waste. This constitutes not only an economic issue, since multiple resources invested in the production will be wasted, but also an environmental problem because of the pollution associated with their disposal. However, BLs comprise an important source of functional compounds (polyphenols and betalains) that could be recovered from the raw material, representing a sustainable solution for the underutilization of this by-product. This study proposes the recovery of polyphenols and betalains using an aqueous ultrasound-assisted extraction (UAE) process at different powers (35, 50, and 100 W) that was characterized and optimized.

RESULTS

UAE significantly enhanced the recovery of bioactive compounds and shortened the time required for extraction in comparison with traditional macerations (35 < 50 < 100 W). During UAE, the temperature of the systems increased as a function of the power applied, favouring the recovery of these phytochemicals. Additionally, a Box-Behnken design and response surface methodology were employed to optimize UAE conditions (90 W ultrasound power, 1:20 solid:liquid ratio, 16 min extraction time), under which the yields were 14.9 mg g^-1 (polyphenols), 949.1 μg g^-1 (betaxanthins), and 562.2 μg g^-1 (betacyanins), consistent with the values predicted by the models.

CONCLUSION

This study enabled the development of a green-solvent UAE process that constitutes an effective post-harvest by-products strategy to minimize losses and increase biomass utilization through the recovery of bioactive compounds from BLs, promoting sustainability in the agri-food chain. © 2020 Society of Chemical Industry.

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.

Synergetic decolorization of azo dyes using ultrasounds, photocatalysis and photo-fenton reaction

In the present work, ultrasound irradiation, photocatalysis with TiO₂, Fenton/Photo-Fenton reaction, and the combination of those techniques were investigated for the decolorization of industrial dyes in order to study their synergy. Three azo dyes were selected from the weaving industry. Their degradation was examined via UV illumination, Fenton and Photo-Fenton reaction as well as ultrasound irradiation at low (20 kHz) and high frequencies (860 kHz). In these experiments, we investigated the simultaneous action of the ultrasound and UV irradiation by varying parameters like the duration of photocatalysis and ultrasound irradiation frequency. At the same time, US power, temperature, amount of TiO₂ photocatalyst and amount of Fenton reagent remained constant. Due to their diverse structure, each azo dye showed different degradation levels using different combinations of the above-mentioned Advanced Oxidation Processes (AOPs). The Photo-Fenton reagent is more effective with US 20 kHz and US 860 kHz for the azo dyes originated from the weaving industry at pH = 3 as compared to pH = 6.8. The combination of the Photo-Fenton reaction with 860 kHz ultrasound irradiation for the same dye gave an 80% conversion at the same time. Experiments have shown a high activity during the first two hours. After that threshold, the reaction rate is decreased. FT-IR and TOC measurements prove the decolorization due to the destruction of the chromophore groups but not complete mineralization of the dyes.

Extraction, optical properties, and aging studies of natural pigments of various flower plants

In this paper, we reported the extraction process of five different flowering plants utilizing different dye extraction methods and solvents (ethanol and water) to choose the best dye removal process. The FTIR spectra revealed the presence of several clear functional groups for all five natural dyes. The analytical studies such as UV spectroscopy, column chromatography, and vacuum evaporation were performed to isolate the dyes from their solutions. The UV-Vis studies on the pigments of flower extracts indicated broad absorption peaks in the visible region including clear bandgaps. Among the studied pigments, Alternanthera ficoidea showed the lowest direct bandgap of 1.69 eV and an Urbach energy value of 6.33 meV. The dye extraction yield rate improvement was extended from 11.7 to 24.7% (water solvent) and 11.3-32.4% (ethanol solvent). Throughout the studies, it was observed that ethanol produced a better extraction for organic dyes than water as a solvent. Aging studies revealed that all the dyes at the room temperature showed better stability with minor changes in the observed optical parameters in oxygen-rich conditions; however, these parameters have shown significant variations at a 60 °C temperature.

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.

Pigment production by Fusarium solani BRM054066 and determination of antioxidant and anti-inflammatory properties

The fungal kingdom has been widely studied as a source of bioactive compounds of interest to the pharmaceutical and food industry. This paper studies the production of natural red pigments by Fusarium solani BRM054066 in the submerged fermentation system, using Doehlert experimental design to determine optimal cultivation conditions. The chemical composition of the red pigment was determined by Nuclear Magnetic Resonance spectroscopy (NMR) and Ultra-Performance Liquid Chromatography coupled to Mass Spectrometry (UPLC-MS). Antioxidant activity was assessed by the ability to sequester of free radical DPPH. In the analysis of anti-inflammatory activity, murine peritoneal macrophages activated by LPS were used, and the gene expression of TNF-α, IL-1β, IL-6, IL-10 and IL-17 was determined using qPCR. As a result, it was found that agitation at 200 rpm and glucose concentration ≥ 20 g/L promote the best results in the production of red pigment. The chemical compounds identified were two naphthoquinones, fusarubin and dihydrofusarubin, and an anthraquinone, a bostrycoidin, being fusarubin the majority compound. The red pigment showed antioxidant activity by scavenge 50% of the DPPH radical, in a concentration of 24 µg/mL. The pigment also showed an effective anti-inflammatory capacity by reducing the overexpression of the pro-inflammatory cytokines TNF-α, IL-1β and IL-6 and promoting the production of anti-inflammatory IL-10 and IL-17, in murine macrophages activated by LPS (p < 0.05). According to the results, the fungus F. solani BRM054066, under optimized conditions of cultivation, proved to be a promising source of biologically active natural pigments with wide industrial applicability.

Applications of Nonconventional Green Extraction Technologies in Process Industries: Challenges, Limitations and Perspectives

This study reviewed five different nonconventional technologies which are aligned with green concepts of product recovery from raw materials on industrial scale, with minimal energy consumption and chemical use. Namely, this study reviewed supercritical fluid extraction (SCFE), pressurized liquid extraction (PLE), microwave-assisted extraction (MAE), ultrasound extraction (UAE) and pulsed electric fields extraction (PEFE). This paper provides an overview of relevant innovative work done in process industries on different plant matrices for functional value-added compounds and byproduct production. A comparison of the five extraction methods showed the supercritical CO2 (SC-CO2) process to be more reliable despite some limitations and challenges in terms of extraction yield and solubility of some bioactive compounds when applied in processing industries. However, these challenges can be solved by using ionic liquids as a trainer or cosolvent to supercritical CO2 during the extraction process. The choice of ionic liquid over organic solvents used to enhance extraction yield and solubility is based on properties such as hydrophobicity, polarity and selectivity in addition to a safe environment.

CONVENTIONAL EXTRACTION OF BETALAIN COMPOUNDS FROM BEETROOT PEELS WITH AQUEOUS ETHANOL SOLVENT

Consumer concern over artificial food additives has stimulated production of pigments from natural sources. The aim of this study was to examine the effects of process variables on the content of colour compounds (betaxanthin and betacyanin) in beetroot peel juice extracted by conventional method. In this research, the extraction processes were carried out according to the central composite design with different process variables. Quantitative measurements of the basic colour compounds in beetroot extract were performed using spectrophotometer. From our experiment, it was found that the most adequate extraction conditions, which gave the highest yield of colour compounds (952.5 mg l–1 of betaxanthin and 1361 mg l–1 of betacyanin), were extraction time 1 h, operating temperature 20 ºC, and solvent ratio 0.8 w/v. Being a conventional heating method, it is a simple and cost efficient process with relatively high yield.

Prospective Study of Microbial Colorants under the Focus of Patent Documents

BACKGROUND

Colorant-producing microorganisms are quite common in nature. These biomolecules present many biological activities such as antitumoral, antimicrobial and antioxidant, in addition to the various nuances of color, making them of special technological importance to the industrial sectors.

OBJECTIVE

This study aims to conduct a technological mapping in the patent, at European patent Office (EPO), in order to evaluate the global panorama of the use of microbial colorants.

METHODS

The experimental design was acquired by the keyword-driven approach through the advanced search in the Espacenet database European Patent Office (EPO). The keywords selected were bacteria or fungi* or yeast or algae or microorganism* but not plant* and pigment* or color* or colorant* or dye* and the International Patent Classification code, C09B61, for prospecting of interest.

RESULTS

There has been a linear increase in patents developed in the last 20 years, with Japan as the largest depositor in the area. The companies Dainippon Ink and Chemicals and Ajinomoto, both being Japanese, are the largest depositors with 20% of all patents. Among the microorganisms, the filamentous fungi appeared in the first place with 32% of documents and the fungi of the genus Monascus were the most frequently used.

CONCLUSION

The use of microbial colorants has been growing among industries, mainly in food sectors, due to the growing demand for products of natural origin. Thus, the increase in research and technological development in the area of microbial colorants can become an economically viable and promising strategy for the various industrial sectors.

Ultrasound-enhanced hair dye application for natural dyeing formulations

Advances made in recent years have allowed the application of colorants obtained from natural sources into textile dyeing. The use of ultrasound in the dyeing method is reported to increase dye uptake and decrease dyeing times. The aim of this work is to further extend the knowledge of natural hair dyes considering the use of ultrasound in the dyeing method with commercially available herbal dyes and using goat hair as a model for human hair. Optimal ultrasonic parameters were selected by considering the effects of sonication times (5, 10 and 15 min), frequencies (44, 400 and 1000 kHz) and total dyeing times (30, 60 and 120 min) in the morphology of the dyed hair and the colour intensity. Damage to the hair surface was evaluated by scanning electron microscopy (SEM) images, differences in colour of the dyed hair was obtained by ImageJ analysis and quantification of dye uptake was determined by UV-visible spectroscopy. The evidence from this study suggests an increase in goat hair coloration with the use of ultrasonic energy. Optimal dyeing conditions in consideration of colouration efficacy without hair damage were identified as sonication at 400 kHz for 10 min with a total dyeing time of 60 min.

Extraction of proteins from microalgae using integrated method of sugaring-out assisted liquid biphasic flotation (LBF) and ultrasound

In this study, a simple sugaring-out supported by liquid biphasic flotation technique combined with ultrasonication was introduced for the extraction of proteins from microalgae. Sugaring-out as a phase separation method is novel and has been used in the extraction of metal ions, biomolecules and drugs. But, its functioning in protein separation from microalgae is still unknown. In this work, the feasibility of sugaring-out coupled with ultrasound for the extraction of protein was investigated. Primary studies were carried out to examine the effect of sonication on the microalgae cell as well as the separation efficiency of the integrated method. Effect of various operating parameters such as the concentration of microalgae biomass, the location of sonication probe, sonication time, ultrasonic pulse mode (includes varying ON and OFF duration of sonication), concentration of glucose, types of sugar, concentration of acetonitrile and the flow rate in the flotation system for achieving a higher separation efficiency and yield of protein were assessed. Besides, a large-scale study of the integration method was conducted to verify the consistency of the followed technique. A maximum efficiency (86.38%) and yield (93.33%) were attained at the following optimized conditions: 0.6% biomass concentration, 200 g/L of glucose concentration, 100% acetonitrile concentration with 5 min of 5 s ON/10 s OFF pulse mode and at a flow rate of 100 cc/min. The results obtained for large scale were 85.25% and 92.24% for efficiency and yield respectively. The proposed liquid biphasic flotation assisted with ultrasound for protein separation employing sugaring-out demonstrates a high production and separation efficiency and is a cost-effective solution. More importantly, this method provides the possibility of extending its application for the extraction of other important biomolecules.

"La Vie en Rose": Biosynthesis, Sources, and Applications of Betalain Pigments

Betalains are tyrosine-derived red-violet and yellow pigments found exclusively in plants of the Caryophyllales order, which have drawn both scientific and economic interest. Nevertheless, research into betalain chemistry, biochemistry, and function has been limited as comparison with other major classes of plant pigments such as anthocyanins and carotenoids. The core biosynthetic pathway of this pigment class has only been fully elucidated in the past few years, opening up the possibility for betalain pigment engineering in plants and microbes. In this review, we discuss betalain metabolism in light of recent advances in the field, with a current survey of characterized genes and enzymes that take part in betalain biosynthesis, catabolism, and transcriptional regulation, and an outlook of what is yet to be discovered. A broad view of currently used and potential new sources for betalains, including utilization of natural sources or metabolic engineering, is provided together with a summary of potential applications of betalains in research and commercial use.

Minimally processed beetroot waste as an alternative source to obtain functional ingredients

Large amounts of waste are generated by the minimally processed vegetables industry, such as those from beetroot processing. The aim of this study was to determine the best method to obtain flour from minimally processed beetroot waste dried at different temperatures, besides producing a colorant from such waste and assessing its stability along 45 days. Beetroot waste dried at 70 °C originates flour with significant antioxidant activity and higher betalain content than flour produced from waste dried at 60 and 80 °C, while chlorination had no impact on the process since microbiological results were consistent for its application. The colorant obtained from beetroot waste showed color stability for 20 days and potential antioxidant activity over the analysis period, thus it can be used as a functional additive to improve nutritional characteristics and appearance of food products. These results are promising since minimally processed beetroot waste can be used as an alternative source of natural and functional ingredients with high antioxidant activity and betalain content.

Natural Colorants: Historical, Processing and Sustainable Prospects

With the public's mature demand in recent times pressurized the textile industry for use of natural colorants, without any harmful effects on environment and aquatic ecosystem, and with more developed functionalities simultaneously. Advanced developments for the natural bio-resources and their sustainable use for multifunctional clothing are gaining pace now. Present review highlights historical overview of natural colorants, classification and predominantly processing of colorants from sources, application on textiles surfaces with the functionalities provided by them. Chemistry of natural colorants on textiles also discussed with relevance to adsorption isotherms and kinetic models for dyeing of textiles.

Trace determination of safranin O dye using ultrasound assisted dispersive solid-phase micro extraction: Artificial neural network-genetic algorithm and response surface methodology

In this study, ultrasound assisted dispersive solid-phase micro extraction combined with spectrophotometry (USA-DSPME-UV) method based on activated carbon modified with Fe2O3 nanoparticles (Fe2O3-NPs-AC) was developed for pre-concentration and determination of safranin O (SO). It is known that the efficiency of USA-DSPME-UV method may be affected by pH, amount of adsorbent, ultrasound time and eluent volume and the extent and magnitude of their contribution on response (in term of main and interaction part) was studied by using central composite design (CCD) and artificial neural network-genetic algorithms (ANN-GA). Accordingly by adjustment of experimental conditions suggested by ANN-GA at pH 6.5, 1.1mg of adsorbent, 10min ultrasound and 150μL of eluent volume led to achievement of best operation performance like low LOD (6.3ngmL(-1)) and LOQ (17.5ngmL(-1)) in the range of 25-3500ngmL(-1). In following stage, the SO content in real water and wastewater samples with recoveries between 93.27-99.41% with RSD lower than 3% was successfully determined.