The effect of steam pasteurization of fermented rooibos leaves and stems on the sensory characteristics and
phenolic composition of infusions was determined. The extent to which this processing step changes the sen-
sory pro
fi
le and whether compositional changes in
fl
uence taste and astringency of the beverage was deter-
mined. These were achieved by examining the changes in the concentrations of soluble solids (SS), total
polyphenols (TP) and 14 individual non-volatile monomeric phenolic compounds, as well as the changes
in 17 aroma,
fl
avor, taste and mouthfeel attributes of rooibos infusions. Steam pasteurization signi
fi
cantly re-
duced the SS, TP and aspalathin contents, as well as the
“
total color
”
(area under the curve: 380 to 520 nm).
Neither the intensities of the taste attributes, sweetness and bitterness, nor the levels of individual phenolic
compounds changed signi
fi
cantly, except that of aspalathin which were signi
fi
cantly reduced. A small but
signi
fi
cant decrease in the astringency of rooibos infusions was observed. The intensities of most of the
aroma and
fl
avor attributes decreased signi
fi
cantly as a result of steam pasteurization.
“
Green
”
and
“
caramel
”
notes exhibited the largest reductions in attribute intensity. The prominent
“
green
”
fl
avor of unpasteurized
rooibos was frequently changed to a
“
hay-like
”
fl
avor after steam pasteurization
The effect of steam pasteurization of fermented rooibos leaves and stems on the sensory characteristics and
phenolic composition of infusions was determined. The extent to which this processing step changes the sen-
sory pro
fi
le and whether compositional changes in
fl
uence taste and astringency of the beverage was deter-
mined. These were achieved by examining the changes in the concentrations of soluble solids (SS), total
polyphenols (TP) and 14 individual non-volatile monomeric phenolic compounds, as well as the changes
in 17 aroma,
fl
avor, taste and mouthfeel attributes of rooibos infusions. Steam pasteurization signi
fi
cantly re-
duced the SS, TP and aspalathin contents, as well as the
“
total color
”
(area under the curve: 380 to 520 nm).
Neither the intensities of the taste attributes, sweetness and bitterness, nor the levels of individual phenolic
compounds changed signi
fi
cantly, except that of aspalathin which were signi
fi
cantly reduced. A small but
signi
fi
cant decrease in the astringency of rooibos infusions was observed. The intensities of most of the
aroma and
fl
avor attributes decreased signi
fi
cantly as a result of steam pasteurization.
“
Green
”
and
“
caramel
”
notes exhibited the largest reductions in attribute intensity. The prominent
“
green
”
fl
avor of unpasteurized
rooibos was frequently changed to a
“
hay-like
”
fl
avor after steam pasteurization
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