DRIED WHOLE EGG POWDER: XXIV. SOME FACTORS AFFECTING COLOUR
A nine filter colour comparator was used to compare egg powders with strips showing the colour of dried egg as received in the United Kingdom. Drying either fresh or frozen eggs did not affect powder colour but Grade B and Grade C eggs gave a product with a more intense yellow colour than Grade A eggs. The area of Canada in which eggs were produced did not affect the colour of the subsequent powder appreciably but powders prepared from eggs produced in May to July, 1945 were a more intense yellow than those from eggs produced in January to April of the same year. Exposure of the liquid egg to light before drying resulted in powders of a duller grey colour than when the liquid was kept in the darkness. Commercial cone-type driers gave powders of a more intense yellow than commercial box-type driers, while powders prepared on the laboratory drier were paler than those prepared on the commercial driers. Coarse powders scattered less of the impinging light than fine powders but the colour quality of the scattered light was unaffected. The addition of a mixture of two dyes, Tartrazme and Sunset Yellow, to liquid egg before drying improved the colour of the resulting powder.