Search results

This study aims to observe the coloring efficacy of coffee-based natural brown colorant for cotton dyeing under microwave (MW) treatment.

The colorant extracted in particular (neutral and acidic) media was stimulated by MW treatment up to 6 min. Dyeing variables were optimized and 2–10 g/100 mL of sustainable anchors (mordants) have been used to get colorfast shades.

It has been found that un-irradiated acidic extract (RE) containing 5% of table salt at 80 °C for 50 min has given high color yield onto MW-irradiated cotton fabric (RC = 2 min). The utilization of 2% of Fe, 10% of tannic acid and 10% of sodium potassium tartrate before bio-coloration, whereas 4% of Fe, 10% of tannic acid and 6% of sodium potassium tartrate after bio-coloration has given good color characteristics. In comparison the application of 6% of pomegranate and turmeric extracts before bio-coloration and 6% of pomegranate and 10% of turmeric extracts after bio-coloration have given good color characteristics. New bio-mordants can be added to get more new colorfast shades.

There is no research limitation for this work. New bio-mordants can be added to get more new colorfast shades.

This work has practical application for artisans, textile industry and handicrafts. It is concluded that colorant from coffee beans can be possible alternative of synthetic brown dyes and inclusion of MW rays for extraction and plant molecules as shade developers can make process more green.

Socially, it has good impact on eco-system and global community because the effluent load is not carcinogenic in nature.

The work is original and contains value-added product for textiles and other allied fields.

The purpose of this study is to evaluate the content of bioactive pigments in coloured callus of Azadirachta indica and to understand the correlation between the callus colours with their bioactive constituents, antioxidant properties and cytotoxicity. These assessments will yield valuable insight into the use of in vitro-derived pigments for possible use as functional natural colourants.

In this study, the authors have successfully developed a protocol to produce leaf-derived callus of various colours with enhanced content of bioactive pigments in A. indica through plant tissue culture. Comparative analysis of the pigments content (chlorophyll, carotenoid, phenolics and anthocyanins) in the coloured callus was conducted, followed by evaluation of its bioactive properties. The antioxidant properties against 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radicals, ferric reducing antioxidant power and cytotox activities of the coloured callus extracts were also reported.

Callus of various colours were successfully produced in A. indica through plant tissue culture, and their valuable pigment content and bioactivity were evaluated. The green callus contained the highest amount of anthocyanin, followed by brown and cream callus. The total anthocyanin contents in both the green and brown callus was more than two-fold higher than that in cream callus. Contrasting observation was obtained for total phenolic content (TPC), where the TPC of cream callus was significantly higher than that in brown callus. Nevertheless, the green callus also exhibited the highest TPC. Green callus also contained the highest amount of total chlorophyll and carotenoid, as well as exhibited the highest antioxidant potential, and was found to be the only extract with active cytotox activity against SKOV-3 cells. Correlation analysis revealed that the excellent bioactivity exhibited by the coloured extracts was strongly correlated with the bioactive pigments present in the callus.

The major bioactive compounds identified in the methanolic extracts of A. indica coloured callus are anthocyanins, phenolics, chlorophylls and carotenoids. Future research work should include improvements in the extraction and identification methods, which may lead to detection and determination of other compounds that could attribute to its bioactivity, to complement the findings of the current study.

This analysis provides valuable information on the application of plant tissue culture as an alternative source for sustainable production of major pigments with medicinal benefits in A. indica for possible use as functional natural colourants.

A comparative study on bioactive pigment production in coloured callus from A. indica leaves and its antioxidant potential and cytotoxicity is original. To the best of the authors’ knowledge, this is the first report detailing a comparative evaluation on the production of coloured callus in A. indica and its relative biochemical composition and bioactive properties.

The review glances upon the colorants used for printing on ceramic substrates by ink jet technology and techniques, chemistry involved during the selection of the colorants.

The ink jet technology is an easy and a convenient technique, specially designed colorants are used for such applications with tailor made properties and features.

New developments in technology and chemistry of colorants to achieve successes in application studies of ceramic substrates.

N/A.

This review glances upon the history, development and practical approach of the current techniques with available dyes and pigments and the techniques involved during the synthesis and application.

The review paper provides information about the development of the inkjet technique on ceramics and available colorants with methods.

The purpose of this study is to evaluate the pattern of carotenoids distribution in three underutilized Malaysian ‘ulam’ or traditional vegetables in Malaysia (Averrhoa carambola, Manihot esculenta and Ipomoea batatas) and their valuable pro-vitamin A activities. These assessments will yield valuable knowledge and insight into the importance of these underutilized traditional vegetables and highlight their potential for applications in medicinal and functional colorant industries.

In this study, the authors have evaluated the distribution of carotenoid compounds in aerial organs of three underutilized traditional vegetables (Averrhoa carambola, Manihot esculenta and Ipomoea batatas). The content of the individual carotenoids were quantified using high-performance liquid chromatography (HPLC) and the organ with the highest accumulation of these compounds were identified. Their valuable pro-vitamin A activities were also reported to indicate their medicinal potential which can further be exploited as pharmacologically active natural colorants and in other applications.

In total, three major chromatographic peaks corresponding to lutein, violaxanthin and β-carotene were observed through HPLC. Among the compounds detected, lutein and β-carotene were the most abundant carotenoids found in both shoots and petioles of all three species. Violaxanthin was only detected in I. batatas shoots. Overall, carotenoid content was observed to be higher in the shoots than in the petioles, where I. batatas contained the highest amount of total carotenoid, followed by M. esculenta and A. carambola. The opposite trend was observed in the petioles, where A. carambola petioles had the highest carotenoid content, while I. batatas contained the least.

The distribution and abundance of these individual carotenoids suggested that the petioles contained the highest amount of carotenoid, contributing to its high pro-vitamin A activity, and could be potentially useful for medicinal application, as it can act as storage site that is not as prone to natural drying or degradation during harvest and sample storage. Future research work should include improvements in the extraction and purification procedures as well as robust identification methods which may lead to better detection and identification of other compounds that could attribute to its bioactivity, to complement the findings of the current study.

This analysis provides valuable information on the importance of underutilized traditional vegetables as important biofactories for sustainable production of valuable pigments (such as carotenoids) with medicinal benefits and can further be exploited in various industries, such as in formulation of functional natural colorants. This study also highlights the importance of petiole as a storage site of pharmacologically active compounds that is not as prone to natural drying or degradation during harvest and sample storage.

To date, there is no previous report found on comparative analysis of carotenoid content and quantification of individual carotenoid concentration in the edible aerial parts of Averrhoa carambola, Manihot esculenta and Ipomoea batatas, although they have been traditionally consumed as “ulam” in Malaysia. Therefore, the results reported in this study provide new insights on carotenoid accumulation in the selected ‘ulam’ species.

The purpose of this study is to address consumer’s preference of natural pigments over synthetic ones and their use in various product developments rather than using synthetic colours. A budding interest of using natural pigments has made researchers to explore several techniques for their stabilization and application in different food products.

In this review, four major natural pigments with potential health benefits have been studied. Betalins, carotenoids, anthocyanins and chlorophylls, in spite of having excellent bio-functional and therapeutic profile, are found to be unstable. Therefore, various nanoencapsulation techniques are used to increase their stability along with their therapeutic properties.

Nanoencapsulation of natural pigments improves their stability, their effect on therapeutic properties and their application in different food products. These findings could be attributed to the encapsulating material as it acts as a barrier and ushers changes in the matrix of natural pigments. Also, nanoencapsulation not only increases stability but also provides several health benefits such as anti-inflammation, anti-cancer, anti-allergic and anti-thrombotic properties.

This paper highlights the openings for the use of nanoencapsulation of natural pigments to stabilize them and use them as a potential colourant and functional ingredient in different food products. Phenols, carotenoids and antioxidant activity are the major factors that are responsible for promoting several health benefits.

This study aims to synthesize some new curcumin containing Aroyl derivatives dyestuffs and study their application in dyeing polyester fabrics, rendering to their antibacterial evaluation.

Modification of curcumin dye was carried out by introducing benzoyl rings through coupling with curcumin. All newly synthesized dyes were characterized by elemental analyses and spectral data (IR, 1 H-NMR and MS). Moreover, the optimal dyeing condition was assigned. Antibacterial activities of the dyed samples at different concentrations of both dyes were studied against gram positive (Staph aureus) and gram-negative (Salmonellatyphimurium) bacteria.

Synthesized curcumin containing benzoyl dyes were applied on polyester fabrics. Meanwhile, these synthesized dyes showed reasonable results towards fastness properties at optimal conditions matching the curcumin dye. In addition to their good fastness assets, synthesized dyes displayed antibacterial efficacy towards both gram positive and gram-negative bacteria. The dyed polyester fabrics showed higher antibacterial efficacy after multiple events of washing.

The synthesized benzoyl containing curcumin moiety was not described before.

Disperse dyes derived from curcumin were prepared via coupling of various diazonium salts of p-aminobenzaldhyde, p-aminoacetopheneone, p-aminobenzoic acid and p-aminobenzoyl chloride with curcumin. The resulting disperse dyes were applied on polyester fabrics at optimal conditions, and antibacterial efficacy of dyed fabrics were evaluated.

Curcumin being was used in food colouration and was effective for dyeing and antimicrobial finishing on textile fabrics. Novel antibacterial dyestuff containing curcumin moieties with benzoyl amine coupling components showed interesting colourant for polyester fabrics. This work introduced innovative disperse dyes for medical textile applications.

The purpose of this paper is to review the nutritional composition, phytochemicals and bioactive compounds of black rice such as flavonoids, phenolic compounds and their health benefits. Black rice has also been used in medicine and for curing diabetes, obesity, cardiovascular diseases and cancer. Green technologies such as microwave-assisted extraction, supercritical fluid extraction and pulse electric field assisted extraction are very useful for the extraction of bioactive compounds as these reduce the use of energy and are environmental friendly. Black rice in different forms can be incorporated in various food products such as bakery, dairy and meat products.

Information and data were collected from different sources such as Google Scholar, Research Gate, online journals available at Banaras Hindu University library, Web of Science and Scopus. A database of more than 80 scientific sources from different sources was made as per the headings and subheadings of the paper.

Black rice is a type of rice species (Oryza sativa L.) and very good source of various nutrients and one of the nutritious varieties of rice. It is a good reservoir of essential amino acids such as lysine, tryptophan, minerals including iron, calcium, phosphorus, zinc and selenium; vitamins such as vitamin B1, vitamin B2 and folic acid. Various recent methods of extraction of bioactive compounds from black rice are suggested.

Researchers and scientists have considered black rice as a “Super Food” because of its nutritional profile. Black rice has antioxidant activity, anti-inflammatory activity, anticancer activity, antihyperlipidemia and antihyperglycemia and anti-allergic activity. There is a need to create awareness among the consumers about its nutritional profile and therapeutic properties.

Whereas the USA is still the largest investment destination for Japanese companies, Japan also accounts as the second largest source of investment in the country. The purpose of this paper is to, empirically, examine the detailed motives of Japanese affiliates when investing in the Southeastern USA, adding to previous research at the national level.

This paper uses a qualitative approach based on the interviews of long-term Japanese investors in the manufacturing and wholesale trade industries in the Southeastern USA and applies text analysis to identify their motives.

The results show that Japanese firms engage in market- and efficiency-seeking foreign direct investment (FDI), and still apply a classic sequence of gradual and incremental market commitments. Market size and growth rate, reducing transaction or transportation costs, and integration within local value chains are the most important to them, whereas competition, creating an export base, lowering tax and accessing skilled labor are of little concern.

The goal of Japanese FDI in the USA is no longer to bypass tariffs but is still part of a complex industrial network of relations which drives further investment. This result can inform policy makers at the state level about the factors that can drive additional foreign investment, such as the establishment of industrial clusters.

This study offers current insights into the motives of Japanese FDI in two industries.

The purpose of this study was to review the information on the scientific efforts and achievements in sustainable industrial textile applications of natural colourants. Then the paper suggests the ways of improving the industrial textile applications of plant-based colourants.

The literature on the chemistry, sources and extraction of plant-based natural colourants was reviewed. The reviewed information was analysed and synthesised to provide techniques for selecting sustainable extraction methods, possible sustainable textile applications of natural colourants and the challenges which hinder industrial textile applications of plant-based natural colourants. The ways of overcoming the challenges of the industrial textile applications of plant natural colourants were suggested. Lastly, the current situation of industrial application of natural dyes in textiles is presented.

Despite the scientific achievement to overcome the challenges of natural colourants for textiles, the global industrial application of natural colourants is still low. Inadequate knowledge of the dyers results into poor performance of the natural dyed textile. The natural dyed textiles are expensive due to the scarcity of raw materials for manufacturing of natural colourants. The selection of suitable extraction, application methods and type of substrate should consider the chemistry of the particular colourant. The society should be educated about the benefits of natural dyed textiles. Cultivation of colourant-bearing plants should be promoted to meet the industrial material demand.

The paper provides a synthesized collection of information about the source, chemistry, extraction, textile application and challenges of plant-based natural colourants. The reviewed information was analysed and synthesised to provide techniques for selecting sustainable extraction methods, possible sustainable textile applications of natural colourants and the challenges which hinder industrial textile applications of plant-based natural colourants. The ways of overcoming the challenges of the industrial textile applications of plant natural colourants were suggested.

The purpose of this work is to investigate the influence of curcumin dye natural colorant on adhesion, mechanical, thermal and electrochemical properties of blend poly (methyl methacrylate) (PMMA) – acrylic polyol.

Extracted curcumin yellow dye colorant from Curcuma Demostica was mixed with PMMA‐acrylic polyol blended polymer in the volume ratios of 9:1, 8:2 and 7:3. The mixtures were applied on pre‐treated cold‐roll mild steel panels. All of the paint coating samples were subjected to potential time measurement (PTM), rapid impact deformation, differential scanning calorimetry (DSC), cross hatch and Fourier transform infrared spectroscopy (FTIR) tests.

The addition of curcumin dye colorant was able to improve the adhesion, flexibilities and resistance against electrolytes penetration of the blended poly (methyl methacrylate) (PMMA) – acrylic polyol polymer paint system. Cross hatch test studies showed that high amount of curcumin dye colorant (AP30 paint system) had the lowest peel‐off coating area from the substrate. The FTIR test had confirmed the high concentration of hydroxyl group in the AP30 sample. The hydroxyl group was able to promote hydrogen bonding between coating substrate interface. The AP30 sample had the highest coating flexibilities when tested with rapid impact test. This was due to the lowest glass transition value T_g which indicated lowest cross linking density in the coating molecules structure. In the PTM test, AP30 paint system had shown the highest rate electrolytes penetration within the AP sample.

The composition of curcumin dye colorant in the polymer blend is limited from 10 percent to 30 percent pigment volume concentration. Increasing the amount of lawsone pigment will result inhomogeneous mixtures.

The AP paint system is suitable for interior applications. This paint system has to be mixed with suitable additive materials to improve its performance for exterior purpose.