61A-23 |
Pregelatinized starches modified with food gums |
X. SHI1, J. Shim2, O. H. CAMPANELLA2, and J. N. BeMiller1. (1) Food Science, Purdue University, 1160 Food Science Building, West Lafayette, IN 47906, (2) Agricultural & Biological Engineering, Purdue University, 1146 ABE Building, West Lafayette, IN 47906 Pregelatinized starches provide critical functionalities in many food products. The possibility to improve their functionality with food gums needs to be seeked out since previous studies have revealed that specific interactions between starch and gum affect their properties. The objective of this study was to produce pregelatinized starch/gum co-products and determine their properties. Various products containing pregelatinized starch (corn, waxy corn, potato, tapioca) and gum (LBG, hydrolyzed guar, alginate) in a ratio of 29:1 were obtained by drum-drying slurries and then milling. The pasting properties of samples (5% TS) were measured using a Rapid Visco Analyzer. Sample was heated from 50 to 95°C, held at 95°C for 2.5 min, and then cooled to 50°C at 12°C/min. Viscosity changes with temperature were monitored. Initial and final viscosities were also measured. Initial viscosity of drum-dried corn starch (<70 cP) was much lower than that of others (350-600 cP). Most samples with added gum had a higher initial viscosity. Especially, the initial viscosity of waxy corn starch pregelatinized with LBG showed a 128% increase over the starch only sample. Pasting curves showed different patterns depending on the type of starch. Drum-dried corn starch gave a pattern typical of native starch, while the other starches gave patterns typical of a pregelatinized starch. Different gums affected pasting properties differently. Final viscosity of drum-dried corn starch in presence of gums was much higher than the initial viscosity, other starches showed relatively less difference between the final viscosity and the initial viscosity. In general it was observed that the presence of gums produced an increase in the final viscosity of samples. As a result, addition of gums may enhance the thickening ability of drum-dried pregelatinized starch. These results suggest that it is possible to make unique and cost effective pregelatinized starch products by adding selective gums.
Session 61A, Carbohydrate
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