Extrusion of process flavorings from methionine and dextrose using modified starch as a carrier

This study aimed to produce process flavorings from methionine and glucose via Maillard
reaction by extrusion method. Modified starch was used as a carrier to reduce the torque
and facilitate the production process. Five formulations of process flavorings with different
ratios of methionine: dextrose: modified starch: water as MS5 (72:18:5:5), MS15
(64:16:15:5), MS25 (56:14:25:5), MS35 (42:12:35:5), and MS45 (40:10:45:5) were prepared
and feded into the extruder. The temperatures of the extruder barrel in zones 1 and 2 were
controlled at 100, and 120˚C, with a screw speed of 30 rpm. The appearance of the obtained
products, torque, pH before and after extrusion, color, volatile compounds, and sensory
evaluation were determined. The extrudate from the formulation containing the highest
amount of modified starch (MS45) gave the highest L* (lightness) of 88.00, which increased
to 93.00 (very light) after grinding into a powder. The process flavorings from all formulations
exhibited similar sensory scores in terms of aroma, taste, and water solubility, with a very
slight difference in color. However, MS25, MS35 and MS45 indicated the torque at 10 Nm/
cm3, while MS5 and MS 15 exhibited higher torque at 18, and 25 Nm/cm3, respectively.
Extruded process flavorings from MS25 were analyzed for their flavor profiles by gas chromatography-
mass spectrometry. Twelve volatile compounds including the key volatile compounds
for sulfurous and vegetable odor type, dimethyl disulfide, methional, and
methanethiol, were found. Four pyrazine compounds presented nutty, musty and caramelly
odor; and 3-hydroxybutan-2-one and heptane-2,3-dione, which gave buttery odor type,
were also detected. The results demonstrated a successful production of process flavorings
using modified starch as carrier to facilitate and reduce the torque during the extrusion
process.