Color is important to many food, both those that are unprocessed and those that are manufactured.
Together with flavor and texture, color plays an important role in food acceptability.
In addition, color may provide an indication of chemical changes in a food, such as browning and caramelization.
For a few clear liquid foods, such as oils and beverages, color is mainly a matter of transmission of light.
Other foods are opaque - they derive their color mostly from reflection.
Some hues occur frequently in foods provided by nature. Green, red, pink, orange, yellow and purple are common. Blue green is rare and no blues exist at all.
It is instructive to consider the fundamental natural rules governing the colors of the world around us and the food we eat.
Color is the general name for all sensations arising from the activity of the retina of the eye. When light reaches the retina, the eye’s neural mechanism responds, signaling color among other things.
Light is the radiant energy in t wavelength range of about 400 to 800 nm. According to this definition color cannot be studied without considering the human sensory system.
The color perceived when the eye views an illuminated object is related to the following three factors: the spectral composition of the light source, the chemical and physical characteristics of the object and the spectral sensitivity properties of the eye.
To evaluate the properties of the object we must standardize the other two factors. Fortunately, the characteristics of different people’s eyes for viewing colors are fairly uniform; it is not too difficult to replace the eye by some instrumental sensor or photocell that can provide consistent results.
There are several systems of color classification; the most important is the CIE system (Commission International de I’Eclairage –International Commission on Illumination. Other systems used to describe food color are the Munsell, Hunter and Lovibond systems.
Added colorants in foods dates from at least 3,700 BC when Egyptians were coloring their candy.
Sugar imported into Europe from Alexandra in the twelfth century was colored with madder and kermes, but the use of cochineal probably predates this.
Awareness of browning would have predated the use of color additives. For an extended shelf life in fresh fruits and vegetables, enzymatic browning must be eliminated.
Foods depending on enzymatic browning for their quality include black tea, dates, prunes and raisin, Non enzymatic browning provides many of the flavors of baking and cooking.
Color of Food
