The aim of this study was to investigate the effects of different variables on lysine loss as determined by
furosine content in corn-based extrudates. Three formulations were prepared to study the effects of
different chemical leavening agents, processing conditions (feed moisture content: 22, 24 or 26%; exit die
temperature: 110 or 150 C), and extrusion cooking methods (with/without CO2 injection) on furosine
formation. Furosine levels of extrudates from both extrusion methods decreased around 20% when feed
moisture content was increased from 22% to 26%. Amadori compounds (precursor of furosine) are
formed in the early stages of the Maillard reaction, and later they are converted to further products.
Consequently, furosine contents of extrudates significantly decreased as exit die temperature increased
from 110 to 150 C. Furosine contents of extrudates produced with sodium- and ammonium-bicarbonate
at 150 C exit die temperature significantly decreased, while the ones produced at 110 C significantly
increased. This may be due to accelerated formation of fructosyllysine at higher pH values followed by
early degradation at 150 C. The CO2 injection method did not have a significantly different effect on
furosine content of extrudates than that produced by the conventional extrusion method, but had a
positive effect on the physical properties of extrudates.