Chemistry Reference
In-Depth Information
Table 14.5.
Aroma compounds identified in dairy ingredients
Whey protein concentrate/
isolate
b
Liquid cheese whey
a
Rennet casein
c
2,3-Butanedione
Butanoic acid
o-Aminoacetophenone
Hexanal
2-Acetyl-1-pyrroline
2-Methoxyphenol
2-Acetyl-1-pyrroline
2-Methyl-3-furanthiol
Hexanoic acid
3-(Methylthio) propanal
2,5-Dimethyl-4-hydroxy-
3-(2H)-furanone
(HDMF)
Maltol
(E,E)-2,4-Decadienal
2-Nonenal
HDMF
(E,E)-2,4-Nonadienal
(E,Z)-2,6-Nonadienal
Sotolon
Short chain acids
(E,Z)-2,4-Decadienal
Decanoic acid
-(Z)-6-Dodecenolactone
Skatole
Dodecanoic acid
Vanillin
a
Liquid Cheddar whey analysed by dynamic headspace/gas chromatography-mass spectrometry (DHS/GC-
MS) (Karagul-Yuceer et al., 2003b; Carunchia-Whetstine et al., 2003a).
b
Whey protein concentrate (80% protein) and isolates were analyzed by gas chromatography-olfactometry/
aroma
extract
dilution
analysis/GC-mass
spectrometry
(GCO/AEDA/GC-MS)(Carunchia-Whetstine
et al., 2005b).
c
Rennet casein analysed by GCO/AEDA/GC-MS (Karagul-Yuceer et al., 2003c).
14.3.4.
Aroma of Fermented Milk Products
Diacetyl and acetaldehyde are important odorants in yoghurt and are
produced by lactic acid bacteria used as starter cultures (Table 14.6). Numer-
ous other fermented milks are produced around the world involving lactic
acid bacteria and/or in some cases fairly complicated sets of microflora in
which a host of volatile compounds play a crucial role in flavour. Fat content
has a profound effect on flavour release, and the extent of this effect is
determined to some extent by the physical chemistry of the compound con-
cerned. Low-fat yogurts (0.2%) were found to release volatiles more quickly
and at a higher intensity but with less persistence than yogurts containing fat
at 3.5 or 10% (Brauss et al., 1999). Sensory assessment of the yogurts showed
significant differences in intensity and speed of onset of flavour, but not the
overall duration of perception. Because different compounds are affected
differently, the physical chemistry of flavour molecules should be considered
when formulations designed to accommodate changes in fat content are
created.
There has been extensive research on the flavour of cheeses, but despite
this effort, only limited information is available on the chemistry of the
flavour of most cheese varieties and the flavour of none is characterized
