Skip to main content
ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Healthy Processed Foods Research » Research » Publications at this Location » Publication #307683
Title: Physicochemical, nutritional and infrared spectroscopy evaluation of an optimized soybean/corn flour extrudate

Author
item GUZMAN-ORTIZ, FABIOLA - National Polytechnic Institute
item Berrios, Jose
item HERNÁNDEZ-SÁNCHEZ, H. - National Polytechnic Institute
item YEE-MADEIRA, H. - National Polytechnic Institute
item SAN MARTÍN-MARTÍNEZ, E. - National Polytechnic Institute
item ROBLES-RAMÍREZ, CARMEN - National Polytechnic Institute
item ROJAS-LÓPEZ, MARLON - National Polytechnic Institute
item MORA-ESCOBEDO, ROSALVA - National Polytechnic Institute

Submitted to: Journal of Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2014
Publication Date: 8/6/2014
Citation: Guzman-Ortiz, F.A., Berrios, J.D., Hernández-Sánchez, H., Yee-Madeira, H., San Martín-Martínez, E., Robles-Ramírez, C., Rojas-López, M., Mora-Escobedo, R. 2014. Physicochemical, nutritional and infrared spectroscopy evaluation of an optimized soybean/corn flour extrudate. Journal of Food Science and Technology. doi: 10.1007/s13197-014-1485-5.

Interpretive Summary: The use of the statistical tool central composite design, using a response methodology, successfully described the effect of the independent extrusion processing variables of feed moisture, die temperature and soybean proportion on specific parameters of product quality, such as expansion index, water absorption index, water solubility index and total color difference. The statistical tool used in the study, allowed to obtain the best processing conditions at 25.8% feed moisture, 160°C die temperature and 58%/42% soybean/corn proportion. The generation of low molecular weight polypeptides, determined in the extruded product, was associated to an increased in in vitro protein digestibility (IVPD). Changes in the protein structure was studied using and Infrared spectroscopy technique. The changes in the protein structures were associated to the increased in IVPD in the extruded sample. This study provides an insight on the relationship between the protein structure and digestibility.

Technical Abstract: A central composite design using RMS successfully described the effect of independent variables (feed moisture, die temperature and soybean proportion) on the specific parameters of product quality (expansion index, water absorption index, water solubility index and total color difference) studied. The optimized processing conditions were obtained with 25.8% feed moisture, 160°C die temperature and 58%/42% soybean/corn proportion. The generation of low molecular weight polypeptides was associated to an increased in in vitro protein digestibility (IVPD) of the extrudate. The FTIR spectra of the soybean/corn mix before and after extrusion showed that the a¬helix structure remained unchanged after extrusion. The band associated with ߬sheet structure showed to be split into two bands at 1624 and 1640 cm-1.These changes in the ߬sheet structures may be also associated to the increased in IVPD in the extruded sample. This study provides an insight on the relationship between the protein structure and digestibility.