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The extent of hydrogenation of two formaldehyde‐treated spray‐dried mixtures of soya bean oil and casein fed to sheep
Author(s) -
Clapperton John L.
Publication year - 1980
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740310504
Subject(s) - chemistry , food science , dry matter , polyunsaturated fatty acid , formaldehyde , casein , soya bean , fatty acid , zoology , biochemistry , biology
Two experiments have been carried out to determine the degree of protection of soya bean oil mixed with sodium caseinate, spray‐dried and treated with formaldehyde. In experiment 1, the mixture contained two parts of oil to one part of sodium caseinate. In experiment 2, the mixture contained six parts of oil to one part of sodium caseinate. The animals also received either no added oil, or the same amount of free oil and, in experiment 2, the powder without any formaldehyde treatment. The basal diet used consisted of equal amounts of dried grass cubes and flaked maize. There were no statistically significant effects on the apparent digestibility of the dry matter, organic matter, nitrogen or total fatty acid. The amount of polyunsaturated fatty acids (18:2 and 18:3) voided in the faeces was not affected by the form of oil. The amount of 18:0 and 18:1 in the faeces was increased by all the different forms of oil. The proportion of polyunsaturated fatty acids in both the solid and the liquid parts of the rumen digesta was markedly increased when the protected powder was added to the diet. This effect was most marked in the liquid. The amount of polyunsaturated fatty acids flowing to the duodenum was markedly increased when the protected powder was given. Of the 18:2 and 18:3 fatty acids added to the food in the soya bean oil, less than 6% passed to the duodenum when either loose oil or unprotected powder was added whereas, when the protected powder was added in experiment 1, 66% of the added polyunsaturated fatty acid passed to the duodenum and the corresponding figure in experiment 2 was 40%. It is concluded that the method of protection used was reasonably effective but that the amount of casein in the second preparation was not sufficient to afford optimum protection.