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Effect of composition and polymorphic form on the hardness of fats
Author(s) -
Feuge R. O.,
Guice Wilma A.
Publication year - 1959
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/bf02641143
Subject(s) - brinell scale , tempering , materials science , vickers hardness test , composition (language) , metallurgy , microstructure , linguistics , philosophy , alloy
Summary Hardness is an important index in the performance of confectionery and other fats. Using an instrument and technique which were essentially a modification of those used in the Brinell test as applied to metals, the effect of composition and polymorphic form on the hardness of fats was investigated. It was found that the hardness of a given sample of fat was influenced by the degree of tempering to which the sample had been subjected. Hardness always increased as the components of a fat were converted to higher‐melting polymorphs. However the hardest test specimens were not obtained with the highest tempering temperatures. Presumably the use of too high a temperature in tempering melted some of the lowermelting polymorphs and allowed them to resolidify in larger crystals producing a softer matrix. Adding progressively larger amounts of one fat to another generally increased or decreased the hardness of the mixture in a more or less uniform manner. Adding small amounts of liquid oil to a hard fat greatly decreased the hardness index. Apparently the hardness index of a given fat decreases as the crystal size increases. It is believed that fats containing a sizable proportion of liquid component will become softer on prolonged storage because the presence of the liquid component makes possible a gradual increase in crystal size.