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Determination of the classes of free monocarbonyl compounds in oxidizing fats and oils
Author(s) -
Keith R. W.,
Day E. A.
Publication year - 1963
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/bf02640715
Subject(s) - oxidizing agent , chemistry , hydrazone , benzene , fraction (chemistry) , organic chemistry , absorbance , flavor , hydrazine (antidepressant) , chromatography , food science
Abstract Simultaneous equations were derived to distinguish and account for the major free monocarbonyl classes in oxidizing fats and oils. The procedure of Pool and Klose was modified to accommodate the equations. The procedure involves conversion of the free monocarbonyls to DNP‐hydrazones by passage of a benzene solution of the sample over an alumina‐DNP‐hydrazine reaction column. The alkanals, alk‐2‐enals and alk‐2,4‐dienals were measured by absorbance readings at 430, 460, and 480 mॖ of a benzene alcoholic‐KOH hydrazone solution. The average error of the procedure in the analysis of total carbonyls in authentic mixtures was 2.4%. It was found that the qualitative composition of the DNP‐hydrazones obtained from milk fat by the reaction column were identical to the volatile carbonyl fraction. Moreover, there was less than 5% difference in the volatile monocarbonyl content of milk fat and the quantity measured by the modified Pool and Klose procedure. The data suggest that the procedure affords a means of measuring volatile or free monocarbonyls of oxidizing lipids. Since the volatile monocarbonyls are directly related to flavor deterioration of oxidizing lipids, it would appear that the free monocarbonyls, as measured by the modified Pool and Klose procedure, should exhibit a corresponding relationship.