Colour reduction in food products containing microalgae

Drum-dried Scenedesmus obliquus and sun-dried Spirulina platensis were separately pulverised and sampled followed by subsequent fractionation of each alga by dry and'wet sieving as well as by use of coulter counter. The colour analysis of each of the fraction as well as that of the total sample of each alga was individually carried out by use of Hunterlab colorimeter. Reflectance from similar size fractions was higher for Spirulina by a value of 4.13 as compared to Scenedesmus. It was found that to increase reflectance significantly and thus produce correspondingly less coloured products, the most suitable algal particle diameter is between 10 and 40 µ m. Spirulina reflects lesser colour compared to Scenedesmus at comparable particle size.