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A dye‐dilution method for estimating solids content of plastic fats
Author(s) -
Zobel H. F.,
Hellman N. N.,
Senti F. R.
Publication year - 1955
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/bf02637711
Subject(s) - chromatography , dilution , filtration (mathematics) , chemistry , absorbance , total dissolved solids , analytical chemistry (journal) , materials science , mathematics , thermodynamics , physics , statistics , environmental engineering , engineering
Summary Solids content of a plastic fat can be estimated by adding a weighed quantity of oil‐soluble dye to a known weight of fat, separating a portion of the dyeoil phase in the ultracentrifuge, and determining the concentration of the dye in the separated oil by absorbance measurements. Since the dye is distributed throughout the oil phase, this yields the amount of oil in the spread; solids represent the difference between the amount of spread taken and the amount of oil determined. Of 37 dyes tested, 1,4‐bis‐methyl aminoanthraquinone and 1,4‐bis‐isopropyl aminoanthraquinone gave satisfactory results for global edible spreads in which solids contents were known from the formulation. The method also was applied to the estimation of solids in butter, margarine, lard, and shortening. Except for lard, results were in good agreement with solids content determined by dilatometric measurements. The measure of true solids which is obtained by this technique, without prior melting of the fat sample, would be valuable in the study of consistency changes arising from diverse processing conditions. Separation of oil phase from a plastic fat by pressure filtration or by capillary absorption in filter paper was less satisfactory than centrifugation in the dye‐dilution method.