Published on Feb 21, 2020
Colour of food is an integral part of our culture and enjoyment of life. Colour is also an important parameter for sensory analysis and consumer preference. However using synthetic colour could be harmful for health of a consumer. Therefore in today’s progressive world a shift from synthetic to biocolour is observed. The present article will enable to understand the what are biocolour, how they can be extracted and where they can be used.
The colour of food is an integral part of our culture and enjoyment of life. They have been used to enhance the aesthetic value of foods. Colour is the most important characteristic of food, since common consumers usually judge quality of the food from its colour. Overall objective for the addition of colour in food is to make the food more appealing and recognizable. Everyone is sensitive to the colour of the food as it can stimulate or suppress one’s appetite. There are several reasons for the addition of colours to food as mentioned below:
1. To make up the colour loss due to light, air, temperature, moisture and storage
2. To correct natural variations in colour
3. To enhance the natural colours associated with a given product.
4. To provide a colourful identity to the colourless or dull looking foods.
5. To provide a colourful appearance to foods.
6. To protect flavors and vitamins that may be affected by sunlight. In the decade of sixty, synthetic colours such as azo dyes became highly popular owing to their low cost and easy availability.
However subsequent toxicological evidences and adverse physiological effects of many such synthetic food colours has resulted in their removal from the permitted colour list for food uses and even more are likely to be banned in near future. Some of them were found to be carcinogenic.
Consequently attention has been shifted towards the use of natural alternatives. Though natural colours enjoy the advantage of being safe but they have drawbacks also such as
Their seasonal production,
Variation in quality and purity from source to source,
Availability in limited shades,
Low concentration in source material,
Difficulties in extraction from the source,
Instability during storage and use,
High cost etc.
What is Biocolour?
BIOCOLOUR word consists of two words BIO meaning natural & COLOUR meaning anything which is used for colouring purpose. Bicolour is any dye obtained from any vegetable, animal or mineral, that is capable of colouring food, drugs, cosmetics or any part of human body. These natural colours come from variety of sources such as seeds, fruits and vegetables, leaves, algae & insects. According to the application a suitable Natural Colour can be achieved by keeping in mind the factors such as pH, heat, light, storage conditions and interaction with other ingredients of the formula or recipe. The storage conditions for natural colours depend on the particular need of the product.
A tight sealed container is best to store the product in a cool storage to preserve colour strength and quality, along with its degree of cooling point. As per FDA colour pigments having a natural origin are exempt from certification. It does not carry any categorization as natural or synthetic. The reason is that the source may be natural but it may or may not be natural to the food it is added to. There are 26 colours permitted to be used in food and 28 to be used in cosmetics and pharmaceuticals. A few commonly used natural colours are Annatto (seed), turmeric, beet juice (root), bell pepper, red cabbage (vegetable), spinach (leaf) etc. Table 1 shows the colour shade and EEC No. of the biocolours.
Why Should Industry Use Biocolours?
With the advent of strict legislative regulations and growing awareness among the consumers about food safety, bicolour have become the choice in the foods as they are extracted from sources of biological origin and are much safer than their synthetic counterparts. Biocolour could be a dye, pigment or substance that can impart colour when added or applied to a food drug, cosmetic or human body but is of biological origin derived from plants, insects or microbes. There are a number of natural colours, but only few are available in a sufficient quantity to be useful for the industry because they are directly extracted from plant, flowers, fruits, leaves and roots. It is therefore advantageous to produce natural colours from different methods. The trend towards natural foods has led in recent years to the substitution of synthetic by natural or nature identical colours in many foods. Table 2 shows the salient features of some important biocolours.
Benefits of Biocolours :
1. They have a protective role against lethal photo oxidation.
2. They inhibit mutagenesis.
3. Use of biocolour may enhance immune systems.
4. They may also lead to inhibition of tumour developments.
Classification of Biocolour:
Food colours have been classified in different ways such as natural/non synthetic/biocolours; synthetic colours & nature identical colours. However food colours essentially biocolours can be classified into three main classes viz. natural colours, browning colours and additives.
1. Natural Colours :
The principal natural colours, most of which in refined form used as additives are the green pigment chlorophyll, the carotenoids which give yellow to red colours; and the flavonoids with their principal subclass the anthocyanins, which impart red to blue colours to flowers and fruits. In recent years, there has been much interest in carotenoids, especially β-carotene. Besides being a natural orange pigment present in carrots, mango, papaya, tomato, winter squash, etc. it is converted in the body to vitamin A and has antioxidant properties. It is believed to have a beneficial effect in reducing the risk of some cancers and perhaps heat diseases.
It can be produced commercially using microorganisms like Dunaliella salina and Blakeslea trispora as these microbes are easy to culture and produce β -carotene in fairly good quantities. The natural colour include: Paprika, Annatto Extract, Anthocyanins, Aronia / Red fruit, Spinach, Beet Juice Colours , ß-Carotene , Beta APO 8 Carotenal , Black Currant, Burnt Sugar, Canthaxanthin, Caramel , Carmine, Carmine Blue , Carminic Acid , Carrot , Chlorophyll, Chlorophyllin , Cochineal Extract , Copper-Chlorophyll, CopperChlorophyllin, Curcumin , Curcumin/CU-Chloro, Elderberry , Grape , Hibiscus, Lutein, Mixed Carotenoids , Paprika Extract, Paprika Oleoresin , Riboflavin, Turmeric etc.
2. Browning Colours :
These are produced during cooking and processing and thus may not be of any direct importance in foods. For ex. As produced during sugar caramelization, baking etc.
3. Additives :
Food additive colours are based on anthocyanins derived from sources such as red grapes or beet but the first additive colour were synthetic dyes which were extensively used as food colourants in nineteenth century and early 1900’s. Some sources of anthocyanins, besides grapes are elderberries, red cabbage, blood orange, the less familiar black chokeberry and sweet potato. Anthocyanins are highly dependent on acidity. As consumer demand for natural product grows, these natural colourants are replacing synthetic food colourants. The most important point about anthocyanins is their strong antioxidant abilities and other health promoting properties. Anthocyanins are polyphenolic group of compounds which have been named ‘Vitamins of the 21’st Century’ due to their impressive medical and health benefits. The commercial production of anthocyanins through tissue culture is being exploited.
. Biotechnology-A boon for production of natural food colours Beverage and food world, July 2005.
. Application of natural colours in surimi seafood’sBeverage and food world, July, 2005.
. Microbial production of colours- Processed food industry, May, 2005.
. Biocolours: New Generation Additives for food, Indian food Industry, sept-oct, 1997, Vol 16(5).
. Food Additives by Branen
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