3A-6 日本色彩学会誌 第 42 巻 第 3号 （2018 年）JCSAJ Vol.42 No.3

Effects of UVA-light on Color Transition of and Dyes and Possible Application of Light-Activated Indicator in Food Package  Kanpicha Suwannawatanamatee Rajamangala University of Technology Thanyaburi, RMUTT Surachai Khankaew Rajamangala University of Technology Thanyaburi, RMUTT Chanprapha Phuangsuan Color Research Center, RMUTT 

KeywordsOxygen Indicator,Intelligent Packaging, Anthocyanin is - pigment ar- Naturals Dyes ranged . The color of anthocyanin can be changed by pH conditions. Normally, plants which are １．Introduction blue, purple, pink and red color can be found antho- Active and intelligent packaging is novel food cyanin in vacuole. Anthocyanin can naturally apply as packaging technology which is rapidly increasing in a dye and additive for food and beverage industry. this century. The active packaging (AP) is packaging Curcumin and curcuminoid are natural dye that can material that can protect the quality or safety of the be found in the root such . Curcumin is a pol- products such as ethylene absorber or inhibitor, mod- yphenol substance which appears yellow and orange ified atmosphere packaging (MAP) and oxygen ab- colors. sorber. Meanwhile, the intelligent packaging (IP) that This research investigated the effects of has a function to monitor or track the change of exter- UVA-light on the color transition of anthocyanin and nal or internal environment of packages and com- curcumin which were used as dyes and possibly ap- municate positions of products to customers such as plied as either an OI or other indicators for food indi- ripeness indicator (RI), ready to serve indicator (RSI), cator application. food spoilage indicator (FSI), time temperature indi- cator (TTI) and oxygen indicator (OI). 2．Materials and methods OI is a tool for checking or monitoring the ox- 2.1 Materials. ygen sensitive food which was packed by the use of either vacuum packaging (VP), MAP or gas flushed Red cabbage and turmeric were used as packaging (GFP). Depended on the oxygen gas in- colorants extracted an anthocyanin and curcumin, re- side the packaging which can be ingressed through spectively. Titanium dioxide (TiO2) and Glycerol were the package material or increased when it was incom- used as a semiconductor (SC) and a sacrificial elec- plete of sealing or leakage due to transportation or tron donor (SED), respectively, that were purchased distribution processe, the OI normally changes its from Sigma-Aldrich (USA). Methyl cellulose (MC, color from its originality to the second color in order to Methocel, Dow Chemical) solution (10% w/v), was warn of quality and safety of the products to custom- served as a binder which was prepared by dissolving ers. MC powder in distill water. Lawrie et al. (2013) have developed the methylene blue (MB) based OI which was comprised 2.2 Preparation of anthocyanin and curcumin-based of the colloidal semiconductor photocatalyst. The MB- oxygen indicator OI could be printed with ink-jet printing system on plastic substrate and could change its color from blue The dye solution (i.e. anthocyanin and cur- to colorless when irradiated with UVA-light. cumin) was prepared by extraction from dried natural

Supplement 48 3A-6 日本色彩学会誌 第 42 巻 第 3号 （2018 年）JCSAJ Vol.42 No.3 powder (i.e. red cabbage and turmeric) with deionized When they were irradiated to the UV light, water for 10% w/v, and then boiled under 60-70 ˚C for the indicator color was increased in L* value with an 20 min followed by filtration of a piece of fabric for 2 activation time average of 960 s, which meaning to times. lighter. The indicator film was the highest at this acti- vation time and close to a steady state, i.e. the color In order to prepare the oxygen indicator, 1.0 was significantly stable despite increase of time acti- g of 10% w/v natural dye was added into the beaker vation. However, the indicator film that SC:SED ratio and mixed with SC (TiO2) and SED (glycerol) using a of 50:1000 revealed a highest in L* when compared magnetic stirrer for 15 min. After that, the solution was with other (Figure 1a). then added 10 mg of 10% w/v MC solution and mixed with a magnetic stirrer for 10 min. The mixture was poured on a Petridis (Ø 100 mm). The solution was leave to dry at the ambient temperature of approxi- mately 25 – 27 ˚C for 24 h, and later it was peeled out and cut into 2 x 2 cm square. The film was then UV irradiated with a 774 mJ.min cm-2 at a 10-cm distance between the sample and the UV lamp. 1a

2.3 SC and SED studies

 Anthocyanin and curcumin based oxygen indicator films were formed according to the method described in 2.2. In addition, the SC and SED were varied in concentrations of 30:750, 30:1000, 30:1500, 1b 50:750, 50:1000, 50:1500, 70:750, 70:1000, and 70:1500. The film was studied on the UV irradiation step for 60 min. During the irradiation, the sample was taken out to measure the change of its color for 0, 15, 30, 60, 120, 240, 480, 960, 1920, and 3600 seconds.

2.4 Color transition measurement

Spectrodensitrometer was used for measur- ing L*, a* and b* of indicator film under CIE Lab during the UV irradiation step. The L*, a* and b* values were obtained from the value used for the calculation of to- 1c tal color difference (∆E) used the following equation

2 2 2 1/2 ∆E = ((L*1 - L*2) + (a*1 - a*2) + (b*1 - b*2) )

3．Results

3.1 Effect of SC and SED concentrations on anthocy- anin-based indicator film

From the results, the oxygen indicator, which prepared from red cabbage extract and Figure 1 change in L* (1a), a*, b* (1b) and color dif- SC:SED ratio of 70:750 and 70:1000, appeared in ference (∆E) (1c) of film SC (titanium purple color while others recipes revealed brown dioxide) SED (glycerol) 30:750, 30:1000, 30:1500, color. 50:750, 50:1000, 50:1500, 70:750, 70:1000 and 70:1500 w/v upon UV irradiation of red cabbage

Supplement 49 3A-6 日本色彩学会誌 第 42 巻 第 3号 （2018 年）JCSAJ Vol.42 No.3

The decrease of a* and increase of b* val- ues of the indicator film from red cabbage extract (i.e. anthocyanin) revealed the change of indicator color from blue-purple to light-blue. These may depend on the exposure time of UV-light. Anthocyanin-based in- dicator films with the SE:SED ratios of 70:750, 70:1000 and 70:1500 obviously appeared high delE, as shown in Figure 1b. 2a

The total color difference (ΔE) value in all cases of anthocyanin-based indicator films was in- creased because of the activation time. The highest ΔE value was the SC:SED ratio of 50:1500 and 70:750. The ΔE value of all samples tended to in- crease when the irradiation time increased (>3600 s), Figure 1c.

3.2 Effects of SC and SED concentrations on curcu- min-based indicator film

The curcumin-based indicator film was orig- 2b inally yellow color and darker owing to the increase of dye concentration. Conversely, this curcumin-based indicator film did not clearly reveal in the color transi- tion since it slowly rose in L* value and reached to the highest of L* value at the 15 s activation time (Figure 2a). Meanwhile, the a* and b* as well as ∆E value of curcumin-based indicator film also revealed a slight change of the values and appeared yellow. The high- est ∆E value showed the SC:SED ratio of 70:1500 when compared to other curcumin-based indicator samples (Figure 2b and 2c).

4．Conclusion These natural-based indicator films used ex- tracted-anthocyanin and curcumin from red cabbage and turmeric, respectively. The indicator films were 2c consisted of the extracted-natural dye, SC (TiO2), SED (glycerol) and MC. The highest ∆E value that il- Figure 2 Changes in L* (2a), a*, b* (2b) and color dif- lustrated a different color film in this research was a ference (∆E) (2c) of film concentration SC (titanium anthocyanin-based indicator film with SC:SED ratio of dioxide) SED (glycerol) 30:750, 30:1000, 30:1500, 50:1500. In the meantime, the curcumin-based indi- 50:750, 50:1000, 50:1500, 70:750, 70:1000 and cator film in all samples did not significantly appear in 70:1500 w/v upon UV irradiation of curcumin-based the ∆E value. However, these results were based on indicator film. theories which can be further studied on the novel natural dye-based temperature indicator. References

1) Young Woo Park, Seong Min Kim, Jae Young Lee & Wonhee Jang, Application of biosensors in smart packaging, Mol Cell Toxicol (2015) 11:277-285.

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The decrease of a* and increase of b* val- 2) Surachai Khankaew, Waraporn Boonsupthip, ues of the indicator film from red cabbage extract (i.e. Chanassa Nandhivajrin, Chiravoot Pechyen and anthocyanin) revealed the change of indicator color Panuwat Suppakul, Effect of Namo-Semiconductors from blue-purple to light-blue. These may depend on and Sacrificial Electron Donors on Color Transition of the exposure time of UV-light. Anthocyanin-based in- a Novel UV – Activated Bio-Oxygen Indicator, 19th dicator films with the SE:SED ratios of 70:750, IAPRI World Conference on Packaging Victoria Uni- 70:1000 and 70:1500 obviously appeared high delE, versity Melbourne 15-18 June 2014, pp. 88-97. as shown in Figure 1b. 2a 3) Katherine Lawrie, Andrew Mills, David Hazafy, The total color difference (ΔE) value in all Simple inkjet-printed, UV-activated oxygen indicator, cases of anthocyanin-based indicator films was in- Sensors and Actuators B 176 (2013) 1154– 1159 creased because of the activation time. The highest 4) Andrew Mills, David Hazafy, Katherine Lawrie , ΔE value was the SC:SED ratio of 50:1500 and Novel photocatalyst-based colourimetric indicator for 70:750. The ΔE value of all samples tended to in- oxygen, Catalysis Today 161 (2011) 59–63 crease when the irradiation time increased (>3600 s), Figure 1c. 5) Andrew Mills, 2005, “ Oxygen indicator and intelli- 3.2 Effects of SC and SED concentrations on curcu- gent ink for packaging food” , The Royal Society of min-based indicator film Chemistry, Vol. 34, pp. 1003-1011.

The curcumin-based indicator film was orig- 2b 6) M.Smolander, E. Hurme and R. Ahvenainen,1997, inally yellow color and darker owing to the increase of “leak indicators for modified-atmosphere packages”, dye concentration. Conversely, this curcumin-based Trends in Science $ Technology, Vol. 8, pp. 101-106. indicator film did not clearly reveal in the color transi- tion since it slowly rose in L* value and reached to the 7) Guelph Foog, 2007, Technology Center Techno highest of L* value at the 15 s activation time (Figure logy Information, p. 367. 2a). Meanwhile, the a* and b* as well as ∆E value of curcumin-based indicator film also revealed a slight 8) J.R.Fried, Prentice Hall PTR , 1995, Polymer Sci- change of the values and appeared yellow. The high- ence and Technology, USA. p. 223. est ∆E value showed the SC:SED ratio of 70:1500 when compared to other curcumin-based indicator 9) Yulia Galagan, Sheng-Hoa Hsu and Wei-Fang Su, samples (Figure 2b and 2c). 2010, Monitoring time and temperature by methylene blue containing polyacrylate film, Sensor and Actua- ． 4 Conclusion tors, pp. 49-52. These natural-based indicator films used ex- tracted-anthocyanin and curcumin from red cabbage 10) Yulia Galagan and Wei-Fang Su, 2008, “Re- 2c and turmeric, respectively. The indicator films were versible photoreduction of methylene blue in acrylate consisted of the extracted-natural dye, SC (TiO2), media containing benzyl dimethyl ketal”, Journal of SED (glycerol) and MC. The highest ∆E value that il- Photochemistry and Photobiology, pp. 378-383. Figure 2 Changes in L* (2a), a*, b* (2b) and color dif- lustrated a different color film in this research was a ference (∆E) (2c) of film concentration SC (titanium anthocyanin-based indicator film with SC:SED ratio of 11) Panuwat Suppakul, 2552, Active and Intelligent dioxide) SED (glycerol) 30:750, 30:1000, 30:1500, 50:1500. In the meantime, the curcumin-based indi- Packaging Technology 50:750, 50:1000, 50:1500, 70:750, 70:1000 and cator film in all samples did not significantly appear in 70:1500 w/v upon UV irradiation of curcumin-based the ∆E value. However, these results were based on 12) Department of science service, 2553, Anthocya- indicator film. theories which can be further studied on the novel nin, pp 2-4 natural dye-based temperature indicator. References

1) Young Woo Park, Seong Min Kim, Jae Young Lee & Wonhee Jang, Application of biosensors in smart packaging, Mol Cell Toxicol (2015) 11:277-285.

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