The ‘Roche Yolk Colour Fan‘—An Instrument for Measuring Yolk Colour

Abstract

INTRODUCTION INCREASING importance is being given to the colour of egg yolk when judging the quality of eggs. Besides the customary standards of measurement such as shape and weight, firmness of the shell, freshness, structure of egg white and yolk etc. the colour of yolk and its year round constancy are decisive criteria in the maintenance of standardized egg quality (Farnsworth and Nordskog, 1955; Bräunlich, 1962, 1966; Bartlett and Podger, 1962; Snyder, 1962; Tagwerker, 1962; Scholtyssek, 1962, 1964; Scholtyssek and Böhm, 1962; Torges, 1964; Mehner et al., 1965; Brown, 1964; Schmidt, 1963). In the last ten to fifteen years a number of papers appeared which are concerned especially with pigmentation of the yolk, e.g. by Rescheleit (1953); Steinegger and Zanetti (1957 Steinegger and Zanetti (1959); Steinegger et al. (1957); Rauch (1959, 1960, 1961); Scholtyssek et al. (1961, 1966); Smetana (1961); Brown (1964); Carlson et al. (1961); Treat (1963); Boguth and Czernicki (1962); Mainguy…