• Korean Journal of Food Science and Technology
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• v.45 no.4
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• pp.416-421
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• 2013

The purpose of this study was to investigate the effects of pH, temperature, light, sugars, and organic acids on the stability of anthocyanin pigments extracted from aronia (Aroniamelanocarpa). Pigments from aronia were most stable at pH 3.0, with maximal absorbance at 514 nm. High temperatures and prolonged heating substantially reduced anthocyanin contents. Anthocyanin levels were as low as approximately 21.70 and 79.63% of normal levels after 300 min of heating at 30 and $100^{\circ}C$, respectively. All of the sugars tested decreased the abundance of aronia pigments, with the levels highest in the presence of maltose, and decreasing progressively in the presence of galactose, sucrose, glucose, and fructose. Among the organic acids tested, citric acid was the most effective in stabilizing the aronia pigment, followed by tartaric acid, malic acid, formic acid, and ascorbic acid. These results provide useful reference data for efforts to use pigments from aronia in processed foods or for developing natural food colorants.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.2
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• pp.330-343
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• 1997

Extraoral maxillofacial prostheses are essential for restoring facial structures that are lost as a result of congenital missing, injuries from accidents, surgical treatments of head and neck cancer. Recently, silicone is the most useful material for this purpose and is more advantageous than other maxillofacial prosthetic materials. However, there are some problems for long-term usage of silicone prostheses due to tear and color change. These are major contributing environmental factors to those problems that are such as ultraviolet light, cleansing agents, changes in humidity and successive adhesion and removal. The aim of this study is to evaluate the physical properties and color changes of maxillofacial prosthetic silicone material by those environmental factors using A-2186 silicone material (Factor II, USA) and two pigments, cadmium yellow medium and cosmetic red. Aluminium molds were fabricated according to the ASTM No. D412 & D624 specifications and resulted specimens from molds were fabicated and treated as follows. Control group and experimental I group were fabricated with 0.1% wt. pigment mixing in silicone elastomer and II-1 group, II-2 group of experimental II group were fabricated with 0.2%, 0.3% wt. pigment mixing in silicone elastomer, respectively. Control group was kept in darkroom at room temperature, I-1 group was kept under natural sunlight during 1week, I-2 group was soaked in 20% soap water during 1wk. I-3 group was successively adhered and removed 200 times on inner region of arm using Daro adhesive-33. Experimental II groups were kept in darkroom at room temperature. Instron universal testing machine was used to measure the % elongation, tensile strength, tear strength of control, experimental I, II groups and reflectance spectrophotometer(COLOR EYE-3000, Macbeth, USA) was used to measure the color differences between control group and experimental I group. The results were as follows : 1. When compared with control group, natural weathering group and 20% soap-water soaking group had no significant differences in % elongation(p>0.05). 2. 200 times successive adhesion and removal group, 0.2% wt. pigment group and 0.3% wt. pigment group had significant decreases in % elongation(p<0.05). 3. Natural weathering group, 20% soap-water soaking group and 200 times successive adhesion and removal group had no significant differences in tensile strength (p>0.05). 4. 0.2%, 0.3% wt. pigment groups had significant decreases in tensile strength(p<0.05). 5. Values of all experimental groups were decreased in tear strength. and 200 times successive adhesion and removal group had significant decrease in tear strength(p<0.05). 6. Natural weathering group and 20% soap-water soaking group had significant color differences(${\Delta}E$) and it could be detectable to naked eye(p<0.05). 7. Color differences between control group and 200 times adhesion and removal group were not detectable to the naked eye (${\Delta}E<1.0$).

• Textile Coloration and Finishing
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• v.28 no.4
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• pp.280-289
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• 2016

Silica microgel was prepared by sol-gel process and then functional groups, epoxy group and ethoxy group, were introduced on the particle by coupling treatment with 3-glysidoxypropyltrimethoxysilane. The functional silica microgel(functional SiGel) formation was identified using FT-IR spectrometry. Phase stability for DMF solution of functional SiGel, PU resin and pigment was evaluated by Turbiscan Lab. And physical properties of artificial suede including hand values, morphology and dyeing fastness were investigated. The mean particle size and the specific surface area of the functional SiGel were $0.77{\mu}m$ and $380m^2/g$. Mixture containing the functional SiGel, PU resin and pigment was more stable than the functional SiGel-free mixed solution. Artificial suede prepared by the functional SiGel had appearance and feeling close to natural suede. The migration fastness, the solvent wicking fastness and rubbing fastness of the artificial suede were enhanced to 4~5 grades, 4~5 grades and 3~4 grades, respectively.

• Journal of Conservation Science
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• v.35 no.6
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• pp.600-611
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• 2019

Yellow to reddish brown soil is generally referred to as hwangto and is used in various industries in Korea. Despite the fact that it is used as an inorganic pigment in dancheong, limited studies have been conducted on the properties of pigments associated with soil and on the mineralogical characteristics of hwangto. This study examines how the pedological and mineralogical features of hwangto affect pigment properties. Results indicate that reddish and yellowish soils have differences in terms of soil texture, mineral composition, oil absorption and stability under light. Reddish soil is mostly found in clay regions, whereas Ulleungdo hwangto is found in loam regions. Yellowish soil is mostly present in the clay loam to loam zones. whereas Haenam hwangto exists in the sandy clay loam zone. As a result of a mineralogical analysis, reddish soil is classified into the feldspar group and clay soil. The major minerals in the yellowish soils are similar however these soils differ in terms of clay mineral compositions. results of the characteristics of pigments prepared by the traditional method revealed that the average particle size is in the range of 10-20 ㎛, reddish soil has an average of 20 ml/100 g higher oil absorption than yellowish soil. In addition, reddish soil is more susceptible to discoloration and deterioration under light than yellowish soil. This study confirms that the soil and mineral characteristics of hwangto affect the physical properties and stability of produced pigments. These result can be used as basic data in future studies natural inorganic pigments using hwangto.

• KSBB Journal
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• v.22 no.5
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• pp.271-277
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• 2007

Natural pigments have many applications like colouring agent, pigments, food additives, and antiseptics. At present, instead of synthetic pigments that have contributed to the development of industry, many kinds of natural pigments have been developed. The constituents of gardenia fruits, Gardenia jasminoides ELLIS, are traditionally known as herb medicine and natural dyes/pigments due to the customer is needs. The fruits produce yellow carotenoid pigments and iridoid compounds. The two main components in the yellow pigments are called crocin and crocetin. The extraction mode of yellow pigment from Gardenia is depended upon the extraction time, temperature, and volume of solvent. Red pigments or blue pigments formed from geniposide and amino acids have been reported a lot. Geniposide, the principal iridoid glucoside contained in gardenia fruit, was hydrolyzed to genipinic acid or genipin as a precursor for the pigment by enzymatic or chemical reaction. These red or blue pigments prepared with materials hydrolyzed of geniposide and amino acid and had properties governed by the electrostatic character of the amino acid. The pigments showed good stability to heat and pH but were gradually bleached by light while the other natural pigments are unstable in light, heat, acid, and base solution. The safety of the pigments was considered to be of little virulences in comparison to synthetic pigments.

• Applied Biological Chemistry
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• v.18 no.2
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• pp.98-101
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• 1975

The components of Gardenia pigment in rind, flesh, fresh fruit and stored fruit, its heat resistance and stability in pH, its dilution and colour-degree were studied. The results are summarized as follows; 1. The components of CROCIN in fresh fruit and stored fruit were 0.0157% and 0.0136% respectively. One year storage of stored fruit resulted in the decrease of 15% of CROCIN. 2. The components of Gardenia pigment in flesh were contained nearly twice as much as in rind. 3. There were traces of ${\beta}-carotene$ and some unknown carotenoid pigments. 4. Gardenia pigment was stable at $100^{\circ}C$ for 60 minutes, but, at $150^{\circ}C$ for 30 minutes, nearly half of them was destructed. 5. Gardenia pigment turned to colurless but was stable in neutral or alkali condition after 10 days. 6. Supercially, dark Gardenia pigment looked yellowish red and thin Gardenia pigment looked yellow: however, each ${\lambda}_{max}$. was all the same.

• Journal of the Mineralogical Society of Korea
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• v.32 no.4
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• pp.259-271
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• 2019

We evaluated mineralogical, physical property and accelerated weather resistance of cinnabar, realgar and orpiment used as cultural heritages and traditional paintings. JB and JS are sample names of cinnabar and JH and UH are sample names of orpiment and Realgar, respectively. As a result of mineralogical property evaluation, Jinsa was identified cinnabar (HgS) and there was no difference in chemical composition according to the grade. UH and JH were confirmed realgar (AsS) and orpiment (As₂S₃), respectively. The polarization characteristics such as shape and color indicate that pigments using our test were natural mineral pigment observed by polarization microscope. Especially, in the case of cinnabar, it is not easy to distinguish between natural mineral pigment and synthetic pigment. But the results of polarization microscope said that cinnabar is natural occurring mineral which have authentic mineral particle and unevenly fracture. As a result of thermal analysis, JH has a higher glass transition temperature and heat stability than UH. After accelerated weather test, cinnabar, realgar and orpiment were striking result in color change because of light degradation. Red color of cinnabar turn into black and the color of realgar and orpiment became brighter than before. JB (meta-cinnabar) is more photosensitivity and faster becoming dark than JB (cinnabar). Finally light transforms realgar (red, As₄S₄) in arsenolite (As₂O₃).

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.345-351
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• 1996

Studies on extraction and color characteristics of purple sweet potato (PSP) pigment were performed to provide the basic information for the utilization of PSP as a new source of natural food colorant. PSP pigment was extracted well with the polar solvents such as distilled water, ethanol, and methanol. but hardly extracted with the non-polar solvents. Among the tested solvents, 20% ethanol solution containing 0.1% citric acid was found to be the most efficient for extraction of the pigment from PSP. PSP contained high amount of pigment not only in the epidermis but also in the flesh of the potato. The PSP pigment was heat stable even under pretreatments such as autoclaving and blanching of the potato before extraction. The optimum temperature of the extraction for the PSP Pigment was decided to be $30^{\circ}C$ by considering the stability and the rate of extraction. The pigment was markedly influenced by the change of pH. The color of the pigment solution was red at the pH range of $1.0{\sim}3.0$, became blue at $7.0{\sim}8.0$, then turned green at $9.0{\sim}10.0$. A characteristic batho-chromic shift of the pigment solution was observed as the pH of the solution increased.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.97-100
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• 1995

The pigments of acetylshikonin and isobutylshikonin isolated from the roots of Lithospermum erythrorhizon were determined over a period of storage for their stabilities influenced by temperatures and metal ions. In dark condition, both pigment solution were unstable at 488 and 560 nm; alcoholic solutions of acetylshikonin pigment were stable at $25^{\circ}C$ and $50^{\circ}C$ for 1 hour, but isobutylshikonin showed severe discoloration within 1 hour at $95^{\circ}C$ . Buffered solutions of acetylshikonin tended to be discolored with the addition of $Fe^{++}$, while those of isobutylshikonin with $Fe^{++}$ and $Cu^{++}$. These studies indicated that acetylshikonin and isobutylshikonin can be used in foods as the natural colorant under selected conditions in case of considering storage temperature and metal ions.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.4
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• pp.313-321
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• 2023

Platycodon grandiflorus (P. grandiflorus) flower is a perennial plant belonging to the family Campanulaceae and has many excellent pharmacological effects, so it has been used as a medicinal ingredient since ancient times. In addition, anthocyanin is a purple or blue natural pigment contained in plant flowers and fruits, and is known as a powerful antioxidant. The purpose of this study was to confirm the dermatological functionality of P. grandiflorus flower extract and the value of the bluish anthocyanin contained in flowers as a cosmetic material as a natural pigment. Firstly, 50% ethanol and 80% ethanol were added to the P. grandiflorus flower and extracted under reflux for 4 h at 25, 60, and 80 ℃, and the pH of each treatment group was similar. Based on the anthocyanin content and chromaticity (E^*ab), 50% ethanol 60 ℃ extraction conditions showing the color development most similar to the natural color of the P. grandifloras flower were selected, and a sample was prepared by concentrating and lyophilizing. The analysis results showed that the total phenol, total flavonoid, and total anthocyanin contents were in the ranges of 23 ㎍/mL, 16 ㎍/mL, and 0.17 ㎍/mL, respectively. The P. grandiflorus flower extract suppressed the production of nitric oxide (NO) and interleukin-6 (IL-6) in lipopolysaccharide (LPS) induced RAW264.7 cells. Furthermore, the P. grandiflorus flower extract showed wound healing effects through the promotion of skin cell migration in TNF-α stimulated human keratinocytes. The stability of anthocyanin and extract color was studied during a storage period of 50 days at various temperatures (4 ℃, 25 ℃, and 45 ℃). Color values (L, a, and b) of the P. grandiflorus flower extract changed over 50 days, whereas the bluish-purple color of the extract was stabilized using 5% maltodextrin. These results suggest that P. grandiflorus flower extract may be useful as a natural cosmetic pigment.