Food Colouring Seminar

Schedule of Food Colouring Seminar 

Time	Session
10.00a.m.-10.20 a.m.	Introduction of Food Colouring
10.20 a.m.-10.40a.m.	Natural Colouring used in Malaysia
10.40a.m.-10.50a.m.	Demonstration of natural colouring physical experiment
10.50a.m.-11.00a.m.	Q&A question and Distribution of Goodies Bags
Tea Break and end of session

Presenter:

1.Low Pinn Yee

2.Chew Wen Lian

3.Kho See Li

Three of the students are from Taylor's University Lakeside campus and their major which is Bachelor of Science( Food Science with Nutrition). A seminar regarding food colouring will be presented to raise concern and awareness to public. In this seminar, the presenters will talk about the natural and synthetic food colouring and the chemistry behind it. The seminar will also cover on the application of the food colouring and the method of extraction of natural coloring.

Register here:

https://docs.google.com/forms/d/1gJ_HgxjZXaW2is9M1G_jR7iEEWDvEcdySLb5jBuUh74/viewform?c=0&w=1

*Registration will be closed on 19 June 2015.

To find out more, please contact us:

Tel: 603-5629 5000

Fax: 603-5629 5001

Email: chemistrythecolor@gmail.com

Introduction

            Food colourings are classified as two different types, which are natural and synthetic colourants. Natural colourings are pigments derived from natural sources such as vegetables, fruits, minerals or animals while synthetic colourings are derived from chemical substances such as aniline, a toxic petroleum product. Permitted food colourings can be listed for reference and usually within the range of E100 to E180. Although natural food colourings are better for health than synthetic food colourings but the production cost is high and may require in larger amount to give same effect as small amount of synthetic food colourings. Therefore, synthetic food colourings are favored by most of the manufacturers in the term of profits.

            Despite of being natural, safe for consumption and cause no harm to health, natural food colourings are less preferred due to its low stability and factors causing offset color lost due to heat, temperature and pH [3]. Natural food colourings tend to be required in larger amount to give colour to food and this may add stronger flavor to the food, which could make the food overly flavored. 

Natural Colouring

Butterfly Pea Flower (Clitoria ternatea)

Butterfly Pea Flower is a blue colour flower that able to use as a food colouring. It is mostly used in South East Asia cuisine. In Malaysia, butterfly pea flower is widely use to prepare Kelantanese nasi kerabu, a blue coloured rice and Nyonya kuih ketan / pulut tai tai which is a blue glutinous rice cake.  In Indonesia, butterfly pea flower is use for naturopathy, an alternative medicine to treat ulcer, red eye, fever, and distended abdomen, irritation in the bladder and urethra and more. Moreover, butterfly pea flower is use to make blue syrup beverage called nam dok anchan (น้ำดอกอัญชัน) and it usually served with honey and lemon. The Thai use this flower as an herbal medicine to promote blood circulation in the scalp, nourishing and strengthening hair follicles to treat hair loss and prematurely gray hair [9].

Kelantanese Nasi Kerabu

Nam Dok Anchan

Kuih Ketan / Pulut Tai Tai

Anthocyanin

Anthocyanin is richly found in butterfly pea flower and it is the chemical compound that gives blue colour to the flower.  Anthocyanin is a water-soluble pigment that may appear red, blue or purple in fruits and vegetable. It absorbed blue, blue-green, and green light according to its chemical structure. Therefore, the light reflected by the fruits and vegetables are in red, purple and green colour. Anthocyanin is very sensitive to pH. When pH is low, it appears in red colour and blue colour at higher pH. Anthocyanin are form when the sugar react with the certain protein in the cell sap. Besides, it is also act as a second metabolites in human body due to its powerful antioxidant property. Hence, anthocyanin provides a health benefits by lower the risk of cancer, aging and also stimulates the blood circulation [14].

*****CLICK IT & experience the MAGIC!!*****

Pandan (Pandanus amaryllfolius Roxb)

It is a tropical plant can be found and popular used as food colouring as well as flavouring among in South East Asia country including Malaysia [15]. In Vietnam, rice often cook with pandan to provide a green appearance which is called Xôi Lá Nếp, while in Malaysia pandan is used in Onde-onde making in order to provide a green coat. Chlorophyll derivative compounds in pandan leaf such as chlorophyll a and chlorophyll b are contribute the green colour to food and can be extracted to utilize as a natural colouring. Onde-Onde Xôi Lá Nếp Chlorophyll Chlorophyll compound absorbs yellow and blue light wavelength of light and reflects green wavelength of light. Chemical structure of chlorophyll is a complex molecule which contain a ring structure (the porphyrin structure) with a central magnesium ion and a long carbohyddrate side chain [5]. The classification of chlorophyll in food label is coloring agent and its E-number is E140 or E141. Chlorophyll helps to prevent cancer as it has the availability to bind with certain carcinogenic chemicals and avoid causing of cell damage [4].

Artificial Food Colouring

Synthetic or artificial food colour are the food dyes that are manufactured chemically, it also applied in pharmaceutical and cosmetic industries. There are many kinds of synthetic food dyes and a few are shown below. Sunset Yellow FCF

This synthetic of the coal tar and azo yellow dye is useful in fermented food which must be heat treated. For instance, lemon curd, marzipan, sweets and more. Sunset yellow is a possible carcinogenic compound. It may cause an allergic reaction in people who have aspirin intolerance. A various symptoms will occur such as swelling of the skin which call angioedema, diarrhea, vomiting, gastric upset, and nettle rash. This food dye also link to the hyperactivity among young children [12].

Allura Red AC

Allura Red AC is a red azo dye which appears in dark red powder. It is soluble in water and it has maximum absorbance at 504nm. Allura cause fewer health risks associated with it in comparison to other azo dyes which is quite similar to sunset yellow FCF [12].

Extraction Method of Natural Colour

Liquid-liquid extraction

It is known as solvent extraction. The principle of this method is based on a mass transfer operation. Plants are made into liquid form and the solution (the feed) is contacted with a solvent which is an immiscible liquid. Two layers of streams were formed and separated the desired extracted (pigments) and undesired components.  However, the limitation of this method is cannot be applied in non-aqueous systems. 

Solid-liquid extraction

Generally, this method is called as leaching process including two steps which are contacting a solid (blended plants) with a solvent and separating the solvent phase and solid residual. The solvent phase contains the desired component such as anthocyanin and chlorophyll. Firstly, the plant blended solution is dissolved in a solvent which able to dissolve the desired component. Followed by using a filter to separate the solvent phase (extract) and solid residual.

Soxhlet extraction
This is a new extracted method created by von Soxhlet in 1879 which is more cost saving method because the solvent that used to extract the desired compound can be recycle. This method widely used by industries because it is able to extract a desired compound has limited solubility or insoluble in that solvent. In fact, the principle of this method is similar with tradition leading method. 

Process of Soxhlet Extraction [6]. 

Quantity Determination of Pigments in Plant

Determination of chlorophyll and anthocyanins can be done based on Lambert-Beer’s Law. . The molar absorbency of each anthocyanin may be slightly different depending on the standard chosen as a mixture of major anthocyanins may be found present in most of the fruits. The total anthocyanin content is measured as cyanidin-3-glucoside due to its wide usage for similar assays and availability. Anthocyanin possesses a molecular weight of 449 and molar absorbency of 26900 at absorbance wavelength of 510 nm at pH 1. 

The amount of chlorophyll can be determined by using a spectrophotometer. The absorbance is proportional to the concentration of chlorophyll presents in the sample [9]. Chlorophyll possesses a molecular weight of 893.49 gmol^-1 and molar absorbency of 10⁵ M^-1 cm^-1 at absorbance wavelength of 663nm.

Disadvantages of Artificial Food Colouring

            Although artificial food colourings are permitted in various types of food products but there are still limitation in every addition. However the amount of food colourings permitted has increased from 12 mg per capita per day to 62 mg per capita per day by FDA. Despite of the amount of certified dyes to be used in food industry, artificial food colourings are still found to be harmful for human body to certain extents when consumed too much or in a long period of time [19]. 

• Cancer 
• Hypersensitivity 
• Allergies 
• Attention Deficit Hyperactivity Disorder (ADHA) 
• Hyperactivity

Conclusion

In conclusion, food colourings are good at improving the appearance of food by giving attractive colours to the food. Colourful foods tend to improve appetite of consumers. Food colourings are classified into natural and synthetic categories where natural food colurings will not cause health problems and synthetic food colourings are found causing health problems such as ADHD caused by red dye, cancer and allergy on people with aspirin intolerance. Natural food colourings include pandan and butterfly pea flower and synthetic food colourings include sunset yellow and allura red dyes were analyzed. There are 3 methods to extract the colour pigments from natural sources such as liquid-liquid extraction, solid-liquid extraction and Soxhlet extraction. 

References

1.  B, N 2015, Nasi Kerabu Lunch-Authentic Malaysian Cuisine, viewed 31 May 2015, <https://eatfeastly.com/meals/d/19183728/?rf=fwebprofinac>.

2.      Brule 2015, Butterfly Pea Flower, viewed 31 May 2015, <http://b-lure.com/butterfly-pea-flowers/>.

3.      Color Maker Inc 2015, Natural vs synthetic, viewed 28 May 2015, <http://www.colormaker.com/natural-ingredients_natural.html>.

4.      Corriher SC 2015, Chlorophyll Supplementation, viewed 31 May 2015, <http://healthwyze.org/index.php/component/content/article/446-you-should-consider-chlorophyll-supplementation.html.

5.      Food Info 2014, Chlorophyll, viewed 2 June 2015, <http://www.food-info.net/uk/colour/chlorophyll.htm>.

6.              Foss 2015, Soxtec™ 8000, viewed 31 May 2015<http://www.foss.dk/-/media/Images/CA/soxtec8000/soxtech_extraction_sketch%20jpg.ashx>.

7.      Freeman, BC & Beattie, GA 2015, An overview of Plant Defenses against Pathogens and Herbivores, viewed 2 June 2015,

<http://www.apsnet.org/edcenter/intropp/topics/Pages/OverviewOfPlantDiseases.aspx>.

8.      Haivenu 2013, Treat Yourself to Malaysian Onde-Onde, viewed 31 May 2015, <http://www.haivenu-vietnam.com/travel-blogs/wp-content/uploads/2013/10/the-onde-onde-cake.jpg>.

9.      Hardesty, J & Attili, B 2010, Spectrophotometry and the Beer-Lambert Law: An Important Analytical Technique in Chemistry, Collin College, U.S, viewed 31 May 2015, <http://www.collin.edu/chemistry/Handouts/1411/Beer's%20Law.pdf>.

10.  Harrington, R 2015, Does artificial food coloring contribute to ADHD in children, viewed 30 May 2015, <http://www.scientificamerican.com/article/does-artificial-food-coloring-contribute-to-adhd-in-children/>.

11.  IndonesiaEats 2011, Bunga Telang (Blue Pea Vine or Butterfily Pea), A Natural Blue Food Dye, viewed 28 May 2015, < http://indonesiaeats.com/blue-vine-butterfy-pea-bunga-telang-teleng-biru/>.

12.  Naz, K 2015, ‘Chemistry of Food Colour’, viewed 2 June 2015, <http://www.feingold.org/Research/PDFstudies/colors.pdf>.

13.  Photosh 2015, Nyonya, viewed 31 May 2015,

<https://scontent.cdninstagram.com/hphotosxaf1/t51.288515/e15/11236047_926628360736636_1980315359_n.jpg>.

14.  Porrarud, S. and Pranee, A 2010, “Microencapsulation of Zn-chlorophyll Pigment from Pandan Leaf by Spray Drying and Its Characteristic”, International Food Research Journal vol.17, p.p1031-1042.

15.  Rusli BF 2011, Extraction and Characterization of Malaysia Pandan Leaves by Soxhlet Method, Bachelor, University Malaysia Pahang, Pahang.

16.  SCIFUN 2015, The Chemistry of Autumn Colours, viewed 31 May 2015, http://scifun.chem.wisc.edu/chemweek/fallcolr/fallcolr.html>.

17.  Selamat MD 2010, Extraction of Green Pigment from Pandanus Odorus, University Malaysia Pahang, Pahang.

18.  Thompson, S 2015, Chapter 21 Natural chemistry products: Anthocyanin as Food Dye, viewed 31 May 2015,

<http://www.smallscalechemistry.colostate.edu/ChemtrekTextbook/Chapter21.pdf>.

19.  Tsuda, S, Murakami, M, Matsusaka, N, Kano, K, Taniguchi, K, Sasaki, YF 2001, ‘DNA Damage Induced by Red Food Dyes Orally Administered to Pregnant and Male Mice’, Toxicological Sciences, vol. 61, no. 1, pp. 92-99, viewed 30 May 2015, <http://toxsci.oxfordjournals.org/content/61/1/92.full>.

20.   Vietnamesefood 2015, Steamed Sticky Poce with Pandan Leaves Recipe (Xôi Lá Nếp), viewed 31 May 2015, <http://www.vietnamesefood.com.vn/vietnamese-recipes/vietnamese-dish-recipes/steamed-sticky-rice-with-pandan-leaves-recipe-xoi-la-nep.html>.