Publication no. C-2003-0211-03R |  VIEW ARTICLE

Effect of Oil Content and pH on the Physicochemical Properties of Corn Starch-Soybean Oil Composites.

G. A. Garzón (1), C. S. Gaines (2,3), A. Mohamed (1), and D. E. Palmquist (1). (1) U.S. Department of Agriculture, Agricultural Research Service, Midwest Area, National Center for Agriculture Utilization Research, 1815 North University Street, Peoria, IL 61604. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by the USDA implies no approval of the product to the exclusion of others that may also be suitable. (2) Corresponding author. E-mail: <gaines31@osu.edu> (3) U.S. Department of Agriculture, Agricultural Research Service, Soft Wheat Quality Laboratory, 1680 Madison Ave, Wooster, OH 44691. Cereal Chem. 80(2):154-158. Accepted October 14, 2002. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. American Association of Cereal Chemists, Inc., 2003.

Starch-lipid composites are a new category of fat replacers. The physicochemical properties of reconstituted corn starch and soybean oil composites (CSSBOC) were evaluated and compared with the properties of reconstituted jet-cooked corn starch (JCCS). Gel firmness, thermal properties, and hot pasting properties at two pH levels and two oil content levels were studied. Amylose content of CSSBOC was unaffected by processing. Buffer pH significantly affected the firmness of the gels made with JCCS. Gels appeared to have a more ordered structure and were firmer at pH 3.4 than at pH 6.0. The firmness of gels made with CSSBOC was not affected by pH or oil content. Retrogradation enthalpy of the gels made with JCCS was significantly affected by pH. Differences in the thermal characteristics of gels made with CSSBOC were attributed to pH and oil content. Peak viscosity, cold paste viscosity, and breakdown viscosity changed significantly when CSSBOC pastes were reconstituted in different pH buffers. Only hot paste viscosity and cold paste viscosity changed significantly when JCCS pastes were reconstituted in different pH buffers. Results establish critical parameters for processing decisions and for the understanding of the behavior of CSSBOC in food system models in which pH is an important factor.