COLOURING OF BUTTER.

Press, Volume LIII, Issue 9520, 12 September 1896, Page 7

COLOURING OF BUTTER.

According to Dr. Luigi Careano, the fact of butter being coloured yellow when the cattle are consuming green fodder, and pale or white when they are living on dry food is probably due to to the decomposition of chloi-ophyl in the organism of the cow, brought about by sulphuretted hydrogen. He made experiments in connection with this phenomenon upon extracts from green grasses, chiefly of the Poa tribe, also with dried samples of the same kinds, and found that not only the alcoholic extracts obtained after treating theni with alcoholised and acidulated water, but also the chlorophyl remaining after evaporation of the spirit, presented different appearances in the spectroscope ; while chloropkyl obtained from fresh grass showed an absorption line in the red, that extracted from dried grass presented no such line. Further, the chlorophyl from fresh grass was converted to a yellow colour by sulphuretted hydrogen in diffused daylight. The investigator's further deductions, based upon the constitution and operation of the digestive organs of the ruminants, lead him to conclude that, probably, the modification of the chlorophyl by sulphuretted hydrogen takes place, and the product passes "into the miU; at least, that there is no physiological objection to this theory, which receives additional support from the fact that hou3 that have aocess to grass lay eggs with

yolks of a deep yellow. The eggs of those, on the contrary, that consume exclusively dry food show a much paler colour in the yolk. The author suggests that a bolus containing chlorophyl should be administered to milch cows fed exclusively on dry fodder, and the colouration of butter obtained in ibis way.