Chemistry Reference
In-Depth Information
4,5-epoxy-(E)-2-decenal were found to contribute to heated butter aroma.
Peterson and Reineccius (2003b) studied the key aroma compounds of
heated butter, using static headspace analysis, and confirmed methional,
(E)-2-nonenal, 1-hexen-3-one, 1-octen-3-one,
-octalactone,
-decalactone,
HDMF and skatole as potent odorants. In addition, they found hydrogen
sulphide, methanethiol, acetaldehyde, diacetyl, 2-heptanone, dimethyl tri-
sulphide, nonanal, butanoic acid, 3-methylbutanoic acid,
-hexalactone and
hexanoic acid. According to these authors, 3-methylbutanoic acid (cheese-
like odour), methional (potato-like), HDMF (caramel-like) and 2-hepta-
none (blue cheese-like) characterize the odour of heated butter. These
compounds were not detected in fresh sweet-cream butter. On the other
hand, odorants such as 2- and 3-methylbutanal, hexanal,
-dodecalactone
and dimethyl sulphide, found in fresh sweet-cream butter, were not detected
in
heated
butter.
Concentrations
of
ketones
and
especially
lactones
increased significantly in heated butter.
Widder et al. (1991) investigated the key odorants of butter oil, using
vacuum distillation for isolation and GCO-MS for the identification of
the volatile compounds. Sixteen potent odorants were identified by AEDA;
the most potent odorants are listed in Table 14.3. Vanillin was reported by the
authors in butter oil for the first time. The most important aroma compounds
with the highest flavour dilution (FD) factors are listed in Table 14.3 (Widder
et al., 1991). In the same study, the odour-active compounds in fresh butter oil
were compared with those in butter oil which had been stored for 42 days at
room temperature. The FD factors of the carbonyl compounds formed by
lipid peroxidation increased.
Volatile compounds in traditional sour-cream butter (Wadodkar et al.,
2002) and in particular of Smen, a fermented butter produced in Morocco
and in other Arab countries, were studied by GCO (Triqui and Guth, 2001).
The results of an AEDA indicate butanoic and hexanoic acids as potent
odorants. The primary mechanism of aroma development in this product is
lipolysis.
14.3.3.
Aroma of Dried Milk Products
Milk powder is used widely as a raw material in food formulation.
Therefore, flavours and off-flavours originating from milk powders could
appear in the final products (Shiratsuchi et al., 1994a). Consequently,
flavour monitoring is a part of the research, development, production
and quality control of milk powders. The volatile flavour compounds of
commercial skim milk powder were studied by extraction of volatiles using
simultaneous steam distillation-extraction under reduced pressure (SDE)
followed by analysis of the extracts by GCMS. The major compounds were
