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Article
Publication date: 31 July 2018

Judith Müller-Maatsch, Johannes Jasny, Katharina Henn, Claudia Gras and Reinhold Carle

The purpose of this paper is to provide insight into the consumers’ perception of natural and artificial food colourants. Furthermore, attitudes towards the application of…

Abstract

Purpose

The purpose of this paper is to provide insight into the consumers’ perception of natural and artificial food colourants. Furthermore, attitudes towards the application of carmine, being technically important and ubiquitously used to impart red shades, are assessed and analysed. Originating from insects, carmine is considered as natural but may arouse disgust.

Design/methodology/approach

In total, 625 individuals were surveyed using an online, self-administered questionnaire to represent a broad cross-section of the German population.

Findings

Independent of their origin, the application of colourants was rejected by 57.0 per cent of the interviewees. In total, 31.8 per cent of the participants stated a neutral attitude, while only 11.2 per cent expressed a positive notion. Most respondents preferred colourants from natural sources to artificial ones. While consumers perceive natural food colourants composed of genuine plant pigments positively, 61.6 per cent of respondents disliked the application of animal-derived colourants, 24.8 per cent of them did neither reject nor like it, and only 13.6 per cent of the interviewees stated a positive attitude towards them. The findings of this paper further indicate consumers’ preference for colourants to be either artificial or plant-derived rather than carmine. Food colourants are being rejected, possibly due to misleading information and confusing labelling. Consequently, information about carmine, including its origin and production, did not increase the aversion to products that are dyed with it, but increased their acceptance.

Originality/value

This study outlines consumer perception and attitudes towards food colourants. For the first time, the findings of this paper report the effect of revealing information about an additive, which initially aroused disgust, and its influence on consumer perception.

Details

British Food Journal, vol. 120 no. 8
Type: Research Article
ISSN: 0007-070X

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Article
Publication date: 15 February 2021

Amruta Joglekar-Athavale and Ganapti S. Shankarling

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.

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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

Research limitations/implications

N/A.

Practical implications

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.

Originality/value

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

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 7 March 2016

D. Nithyananda Sastry, T. Prabhakar and M. Lakshmi Narasu

– This paper aims to isolate fungal strains producing natural colours, explore their application as colourant in paints and develop cost-effective durable natural paints.

Abstract

Purpose

This paper aims to isolate fungal strains producing natural colours, explore their application as colourant in paints and develop cost-effective durable natural paints.

Design/methodology/approach

Fungal strains producing natural colours of different shades were isolated. Colourant production was carried out by fermentation method. Natural lime, milk, oil-in-water emulsion paints using natural microbial colours and eco-friendly ingredients were prepared. Bio-paint applications were carried out and evaluated.

Findings

Our results indicate that microbes in general and fungi in specific represent dependable source of variety of natural colours, and cost-effective durable natural paints can be prepared with commonly available natural ingredients using scientific information based on history of paints.

Research limitations/implications

Natural colours are gaining importance because of their use in health, nutrition, pharmaceutical, textile and environmental applications. Nature is quite rich in several types of colourants. Chemical synthesis of synthetic dyes is complex and not environmental friendly. Microbial dyes manufactured can evade inherent environmental problems of synthetic dyes and offer significant opportunity as a colourant in paints. However, only generally regarded as safe microbial strains are to be considered for colour production.

Practical implications

Choosing natural alternatives to protect the health and environment is the need of hour. Fungal colourants are relatively more stable and robust and offer significant opportunity as a colourant in paints. Cost-effective durable natural paints can be prepared using selected stable fungal colourants with commonly available natural ingredients. High diversity of rich and complex natural colourants can be obtained from microorganisms. With the available techniques of fermentation, natural colours can be produced in large quantities of on an economically viable scale and explored for their applications.

Social implications

Bio-paints are eco-friendly natural paints, low volatile organic compounds (VOC) paints or organic paints alternate to conventional paints. Most of these natural paints are durable, breathable, prevent moisture problems, contribute to a positive room climate, use safer technology and are less energy-intensive than conventional latex paints to produce. These paints improve indoor air quality and reduce urban smog and offer beneficial characteristics such as low odour, excellent durability and a washable finish.

Originality/value

Many of the old art works that still survive today are a tangible proof and evidence of beauty and durability of natural paints. Organic materials used in these paints include natural pigments of mineral, plant and animal origin and other raw biodegradable ingredients. Successful commercialisation of many microbial pigments for food and textile applications is reported in literature. Therefore, present research work aims at developing natural paints using microbial pigments and recipes that have been successfully used by people for years.

Details

Pigment & Resin Technology, vol. 45 no. 2
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 5 January 2015

Jyoti Srivastava and Padma S. Vankar

This paper aims to study carotenoids as a natural food colorant from Canna flowers. There is a growing demand for eco-friendly and non-toxic colorants, specifically for…

Abstract

Purpose

This paper aims to study carotenoids as a natural food colorant from Canna flowers. There is a growing demand for eco-friendly and non-toxic colorants, specifically for health-sensitive applications such as colours of food and textiles. Red Canna variety can be grown in normal garden situations and gives ample of flowers yielding good amount of natural colorant for both the purposes.

Design/methodology/approach

In the present work, ultrasound extraction of natural colorant from Canna indica flowers has been studied. The use of ultrasound is found to have a significant improvement in the extraction efficiency of colorants obtained from dry and fresh Canna flowers in different mediums. Ultrasonic cavitational processing has twofold advantages, it is an eco-friendly and cost-effective process.

Findings

The total carotenoid content in dry and fresh flower extract was found to be between 136.56 and 978.89 mg/kg. The assessment of antioxidant activity (AOA) in dry and fresh flower extract was found to be 5.78-78.33 per cent assayed by scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and identified by electron paramagnetic resonance (EPR) studies.

Research implications/limitations

The use of ultrasonication for the extraction of colorant has been the main feature and a step towards technological advancement in the area of finding newer method of efficient extraction of the colorant.

Practical implications

The ease of extraction due to ultrasound waves has been the highlight.

Originality/value

It is for the first time that the phytochemical data of red Canna flower and has been studied, the total carotenoid content and antioxidant activities of different extracts of Canna were measured. The extraction of natural dye from C. indica flowers using ultrasound has been found to have significant improvement in the extraction efficiency of the colorant obtained from flowers.

Details

Pigment & Resin Technology, vol. 44 no. 1
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 15 March 2013

Z.H.Z. Abidin, K.M. Nasir, S.K.M. Jamari, N. Saidon, S.V. Lee, N.A. Halim and R. Yahya

The purpose of this work is to investigate the correlation characteristics in mechanical, thermal and optical properties of PMMA‐acrylic polyol polymer blends mixed with…

Abstract

Purpose

The purpose of this work is to investigate the correlation characteristics in mechanical, thermal and optical properties of PMMA‐acrylic polyol polymer blends mixed with lawsone natural dye for coating paint application.

Design/methodology/approach

Natural brownish dye colorant was extracted from Lawsonia Inermis leaves used as a dye colorant in this paint coating system by using ethanol as the solvent. Poly(methyl methacrylate) (PMMA), blended with acrylic polyol was used as the binder system. The ratio of PMMA to acrylic polyol was varied with PMMA dominance. The dye colorant was fixed at 10 wt percent.

Findings

The potential time measurement tests showed that the dye colorant paint system with 10 wt percent of acrylic polyol has the highest coating resistance against electrolyte penetration. The dye colorant paint system with 30 wt percent acrylic polyol performed better in mechanical tests such as cross‐hatch and impact resistance. The dye colorant paint system molecular crosslinks were analysed by using the fourier transform infrared spectroscopy (FTIR) and X‐ray diffraction spectroscopy.

Research limitations/implications

The ratio of lawsone dye colorant in the polymer blends is found limited to 10 percent. Increasing in the percentage of lawsone dye colorant will cause inhomogeneity in coating paint sample.

Originality/value

A new formulation of natural dye colorant paint system with 10 percent wt dye volume concentration of lawsone as pigment was obtained.

Details

Pigment & Resin Technology, vol. 42 no. 2
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 7 November 2016

Aly R. Abdel-Moemin

The purpose of this paper is to analyse the content and some synthetic food colourants, total fats, nitrate and nitrite in both advertised foods (AF) and serum and urine…

Abstract

Purpose

The purpose of this paper is to analyse the content and some synthetic food colourants, total fats, nitrate and nitrite in both advertised foods (AF) and serum and urine samples of children (8 to 12 years) and their impact on childrens’ diet and health.

Design/methodology/approach

Analysis of the content of the AF was done by watching the three Egyptian children’s channels (ECC) for 38 hours. Amaranth, Indigo Carmine, Tartrazine, nitrate and nitrite were analysed in all AF and in serum and urine specimens of children. However, total fats were only analysed in the advertised processed meats and in the restaurant dishes. Lipid profile was also estimated in children.

Findings

The AF accounted for 46-54 per cent of the total advertisements presented. The advertised restaurant dishes were predominantly high in fats, 63 and 55 per cent in restaurant dishes and processed meats, respectively. Tartrazine was the only food colourant found in soft drinks and jelly powders measuring 0.2-15 µg/ml and 25-125 µg/g, respectively. The average levels of total nitrate and nitrite were higher than the acceptable daily intake of the Egyptian and WHO limits (125 mg/kg). Urinary Tartrazine and serum and urinary total nitrate and nitrite were significantly higher in the viewers’ children for the ECC and at borderline for lipid profile compared to non-viewers’ children.

Research limitations/implications

The most harmful effect of these advertisements is the cumulative effect of AF that undermines progress towards a healthy diet for children. AF may expose children to non-communicable disease in the future.

Practical implications

The local policy context requires action to set clear rules for children’s food advertising and monitor processed meat products to tackle exceeded levels of nitrate and nitrite.

Originality/value

This is one of the first studies to analyse colourants, fats, nitrate and nitrite in AF and in the serum and urine of children. This research shows a large number of AF (1,112) in the ECC for 38 hours with statistically significant increase of Tartrazine, nitrate and nitrite in AF (p<0.0001) and in biological fluids (p<0.05).

Details

British Food Journal, vol. 118 no. 11
Type: Research Article
ISSN: 0007-070X

Keywords

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Article
Publication date: 15 March 2013

Z.H.Z. Abidin, N.N. Naziron, K.M. Nasir, M.S. Rusli, S.V. Lee, M.Z. Kufian, S.R. Majid, B. Vengadaesvaran, A.K. Arof, R.M. Taha and R. Yahya

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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 Tg 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.

Research limitations/implications

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.

Originality/value

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.

Details

Pigment & Resin Technology, vol. 42 no. 2
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 29 June 2012

N. Aziz, N.A. Mat Nor, A.F. Mohd‐Adnan, R.M. Taha and A.K. Arof

The purpose of this paper is to evaluate the stability of anthocyanin colorant with and without ferulic acid (FA) stabilising agent in a polyvinyl alcohol (PVA) binder…

Abstract

Purpose

The purpose of this paper is to evaluate the stability of anthocyanin colorant with and without ferulic acid (FA) stabilising agent in a polyvinyl alcohol (PVA) binder coating system.

Design/methodology/approach

The anthocyanin colorant was extracted using methanol acidified with 0.5% trifluoroacetic acid (TFA). FA was added to improve thermal stability of the colorant. The FA added colorant was mixed with PVA to develop a coating system. To test the ability of the coating mixture to withstand heat in the liquid state, spectroscopic studies were carried out in the visible region of the electromagnetic spectrum when the liquid samples had cooled down to room temperature after being heated at 80 and 90°C for 30 minutes. This procedure was repeated six times until a total heating time of 180 minutes has been accomplished. The liquid samples were also coated on glass slides, cured and then stored in different incubators at 30, 40 and 50°C. The visible spectrum was taken everyday for 30 days to study the effect of storage temperature. Spectroscopic results were analysed in terms of intensity rate percentage (IRP).

Findings

In the liquid state, the anthocyanin‐PVA mixture without FA showed lower absorbance compared to the mixture containing FA after heating at 80 and 90°C. This shows that FA can enhance the intensity of absorbance of the liquid coating mixture. The mixtures containing FA show increase in absorbance with increase in heating time. The same results are obtained for the coating on glass substrate where FA containing coatings show increase in IRP with time for all storage temperatures. Coating with 1% FA content showed better enhancement and stability.

Research limitations/implications

The colour of the untreated samples quickly faded during heating and storage at different temperatures. In this study, the addition of 0.5% and 1% FA stabilised and enhanced the colour intensity at 30, 40 and 50°C. Further improvements may find the mixture suitable as paint or coating materials and as nail varnish.

Practical implications

The results indicate the possibility of applying the FA stabilised anthocyanin‐PVA, colorant‐binder composition in a coating system.

Originality/value

The use of anthocyanin from M. Malabathricum as a colourant in a coating system or nail varnish is original. Anthocyanin pigments are normally used as colorant in foods.

Details

Pigment & Resin Technology, vol. 41 no. 4
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 27 January 2020

Hossein Barani and Homa Maleki

Finding blue colorants from natural sources is extremely difficult and, usually, the anthocyanin compounds are used for producing the blue color. This study aims to apply…

Abstract

Purpose

Finding blue colorants from natural sources is extremely difficult and, usually, the anthocyanin compounds are used for producing the blue color. This study aims to apply the Red Cabbage as a natural colorant to obtain different colors on wool yarn, as well as specify the optimum dyeing condition by response surface methodology for obtaining a blue color.

Design/methodology/approach

The effect of dyeing process parameters such as mordant concentration, dyeing time, pH of dyeing bath and dyeing temperature examined in the color characteristics of the dyed wool samples.

Findings

The obtained results indicated that the diverse colors achieve by varying the dyeing process parameters, which is in the range of 26° up to 271°. The non-mordanted dyed wool samples showed a red and red brownish color (Hue angle = 26° up to 70°), and the mordanted dyed wool samples showed a blue and blue-greenish color (Hue angle = 230° up to 271°). The obtained blue color with the optimized dyeing condition presented a considerable good wash and lightfastness.

Originality/value

This study provides a promising application of Red Cabbage as a natural colorant for obtaining different colors by varying the dyeing process parameters such as pH and stannous ion concentrations. The stannous ions yielded a co-pigmentation and presented a blue color on wool fibers, which is extremely difficult to obtain with natural colorant.

Details

Pigment & Resin Technology, vol. 49 no. 3
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 8 August 2018

Noraini Mahmad and R.M. Taha

The purpose of this study is to investigate the effects of pH, UV-B radiation and NaCl on anthocyanin extracted from vivid blue petals of Clitoria ternatea L. (legume…

Abstract

Purpose

The purpose of this study is to investigate the effects of pH, UV-B radiation and NaCl on anthocyanin extracted from vivid blue petals of Clitoria ternatea L. (legume crop), as a potential natural colourant for food, dye or coating technology.

Design/methodology/approach

The anthocyanin from petals of Clitoria ternatea was extracted using 0.5 per cent trifluroacetic (TFA) in methanol solution. The liquid colourant was exposed to different pH (1, 4.5 and 5.5), UV-B radiation and sodium chloride (NaCl). The results were compared using UV-vis spectrophotometric analysis.

Findings

Anthocyanins are sensitive and quickly degrade in the presence of light. In the dry powder form, the anthocyanin is easier to maintain and preserve (storage).

Research limitations/implications

Anthocyanins extracted from vivid blue petals of Clitoria ternatea L. are sensitive and quickly degrade in the presence of light.

Practical implications

The anthocyanin pigments extracted from Clitoria ternatea L. petals with methanolic acid were successfully coated on glass slides. The combination of binders and pigments had produced environmental paint which added with stabilisers (additives) for better durability. Acrylic has been known for its high weathering and embrittlement resistance, good mechanical and electrochemical properties and gloss retention.

Social implications

This anthocyanin is suitable as natural colourant especially in baby products, cosmetics production or for coating and varnish application.

Originality/value

Till date, the natural colourant of Clitoria ternatea L. petals is widely used in food. However, this result is a new finding, as there is no report on the potential of applications of this natural colourant for coating technology. Therefore, the current study with appropriate extraction method was significantly based on the relevant literatures of coating production from pigment by using other plant species. The findings and conclusion highlight the practicality as the potential applications in coating technology.

Details

Pigment & Resin Technology, vol. 47 no. 6
Type: Research Article
ISSN: 0369-9420

Keywords

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