Es. De Brito et al., Effect of autoclaving cocoa nibs before roasting on the precursors of the Maillard reaction and pyrazines, INT J FOOD, 36(6), 2001, pp. 625-630
Citations number
20
Categorie Soggetti
Food Science/Nutrition
Journal title
INTERNATIONAL JOURNAL OF FOOD SCIENCE AND TECHNOLOGY
Nibs of raw cocoa (N) were roasted (R) at 150 degreesC for 38 min. Some sam
ples were autoclaved at 121 degreesC for 15 min (A) and roasted (AR) at 150
degreesC for 38 min. The samples were then analysed for moisture content,
water activity (a(w)), reducing sugar and amino group (alpha -N) levels and
, absorption at 275 nm (A(275)) for a trichloro acetic acid (TCA) extract a
nd at 280 nm (A(280)) for the distillate. Tri- and tetramethylpyrazines wer
e quantified by solid phase micro extraction-gas chromatography (SPME-GC).
There was a reduction in the levels of alpha -N, in the order N > A > R > A
R. The same sequence was observed for reducing sugars. The tetramethylpyraz
ine had an Area(pyrazine)/Area(internal standard) of N < R < A < AR and for
trimethylpyrazine the order was N < A < R < AR. After autoclaving, the A(t
etra)/A(tri) decreased from 31.30 (N) to 11.06 (A). With roasting, this rat
io was 2.18 (R) and 2.58 (AR). Autoclaving nibs before roasting significant
ly influenced the levels of compounds which contribute to cocoa flavour for
mation and increased the concentration of tri- and tetramethylpyrazines in
the headspace of cocoa samples. Autoclaving prior to roasting also affected
the sensory properties of the samples.