CHANGES IN STARCH AND PROTEIN ON EXTRUSION OF CORN STARCH AND SUNFLOWER PROTEIN BLENDS

We investigated the use of electron spin resonance spectroscopy (ESR) and the spin labelled fatty acid, 16 doxyl-stearic acid (16-DSA) in th e study of starch and protein modification during extrusion processing of corn starch (CS), corn meal (CM), and their blends with sunflower protein isolate (SPI). Spectra due to binding of the spin probe to sta rch and protein were;identified. Changes in spectra after extrusion of all materials indicated that: (1) similar to 90% of the starch was mo dified (gelatinized); (2) The globular protein structure was disrupted . These changes demonstrate that spin probes and ESR spectroscopy may be used to study starch and protein modification during extrusion and other food processes.