Starches are widely utilized in foodstuffs as salad dressing, sauce, and processed foods. however, the functional properties of native starches are affected by processes such as heat treatment, acidity, and high shear stress. Starches can be modified chemically in order to have characteristics required by industries, but not to attribute the food a "natural and safe" label. Another option is to obtain native starches resistant to food processing stress conditions. The objective of this paper is the evaluation of commercial native organic starches under food processing stress conditions such as heat treatment and acidity. Suspensions of native functional organic starches (9460 and 9560, National Starch, and Chemical Industry) were prepared at 5% concentration (w/v), acidified with 1M citric acid, or autoclaved at 121 °C for 30 minutes. The results were evaluated by optical microscopy, flow curve, and viscoelastic aspects which were obtained by steady and oscillatory rheology. The acidity and heat treatment increased the starch gels structure that resisted to the processing stress conditions. The starch gels exhibited non-newtonian (pseudoplastic) and thixotropic behavior. Flow data were fitted to the Power Law or herschel-bukley models. All samples exhibited gel-like viscoelastic behavior which was preserved under several stress conditions.292412419Ahmad, F.B., Willians, P.A., Effects of galactomannans on the thermal e rheological properties of sago starch (2001) Journal of Agricultural and Food Chemistry, 49 (3), pp. 1578-1586Official Methods of Analysis (1997) 16 ed. Washington, , ASSOCIATION OF OFFICIAL ANALYTICAL CHEMISTS - AOACOfficial Methods of Analysis (1975) Washington, , ASSOCIATION OF OFFICIAL ANALYTICAL CHEMISTS - AOACBhandari, P.N., Singhal, R.S., Kale, D.D., Effect of succinylation on the rheological profile of starch pastes (2002) Carbohydrate Polymers, 47 (3), pp. 365-371Breton-Dollet, V., (1996) Influence du couple temperature/cisaillemet sur les propriétés rhéologiques de preparations à base d'almidon. villeneuve d'Ascq, , France, These (Doctorat) - INRAEllis, R.P., Starch production and industrial use (1998) Journal of Science Food Agriculture, 77, pp. 289-311Han, X., Influence of maize starch granule-associated protein on the rheological properties of starch pastes. Part I. Large deformation measurements of paste properties (2002) Carbohydrate Polymers, 49 (3), pp. 315-321Hirashima, M., Takahashi, R., Nishinari, K., Effects of adding acids before and after gelatinization on the viscoelasticity of cornstarch pastes (2005) Food Hydrocolloids, 19 (5), pp. 909-914Ikeda, S., Nishinari, K., "Weak-gel" type rheological properties of aqueus dispersions of nonaggregated r-carrageenan helices (2001) Journal of Agricultural and Food Chemistry, 49 (9), pp. 4436-4441Juliano, B.O., A simplified assay for milled-rice amylose (1971) Cereal Science Today, 16 (10), pp. 334-340Kuhn, K., Schlauch, S., Comparative study about commercially available starches for high shear and high temperature applications in food (1994) Starch/Stärke, 46 (6), pp. 208-218Lagarrigue, S., Alvarez, G., The rheology of starch dispersions at high temperatures and high rates: A review (2001) Journal of Food Engineering, 50 (4), pp. 189-202Marques, P.T., Study of gelatinization process and viscoelastic properties of cassava starch: Effect of sodium hydroxide and ethylene glycol diacrylate as cross-linking agent (2006) Carbohydrate Polymers, 66 (3), pp. 396-407Martinez, C., Cuevas, F., Evalución de la calidad culinaria y molinera del arroz (1989) Guia de estudo do Centro Internacional de Agricultura Tropical - CIATNayouf, M., Loisel, C., Doublier, J.L., Effect of thermomechanical treatment on the rheological properties of crosslinked waxy corn starch (2003) Journal of Food Engineering, 59 (2-3), pp. 209-219Nurul, I.M., Azemi, B.M.N.M., Manan, D.M.A., Rheological behavior of sago (Metroxylon sagu) starch paste (1999) Food Chemistry, 64 (4), pp. 501-505Nguyen, Q.D., Jensenand, C.T.B., Kristensen, P.G., Experimental and modelling studies of the flow properties of maize and waxy maize starch pastes (1998) Chemical Engineering Journal, 70 (2), pp. 165-171Ramaswany, H.S., Rheological properties of gelatinized starch solutions as influenced by thermal processing in an agitating retort (1995) Journal of Food Engineering, 25 (3), pp. 441-454Rao, M.A., Rheological behaviour of heated starch dispersions in excess water: Role of starch granule (1997) Carbohydrate Polymers, 33 (4), pp. 273-283Sanderson, G.P., Polysaccharides in Foods (1981) Food Technology, 7 (83), pp. 50-57Singh, N., Morphological, thermal and rheological properties of starches from different botanical sources (2003) Food Chemistry, 81 (2), pp. 219-231Steffe, J.F., (1996) Rheological Methods in Food Process Engineering, p. 418. , 2 ed. Michigan: Freeman PressSriburi, P., Hill, S.E., Extrusion of cassava starch with either variations in ascorbic acid concentration or ph (2000) International Journal of Food Science and Technology, 35 (2), pp. 141-154Sriburi, P., Hill, S.E., Mitchell, J.R., Effects of ascorbic acid on the conversion of cassava starch (1999) Food Hydrocolloids, 13 (2), pp. 177-183Takeda, Y., Structures of branched molecules of amyloses of various origins and molar fractions of branched and unbranched molecules (1987) Carbohydrate Research, 165 (1), pp. 139-145Tarrega, A., Vélez-Ruiz, J.F., Costell, E., Influence of milk on the behaviour of cross-linked waxy maize and tapioca starch dispersion (2005) Food Research International, 38 (7), pp. 759-768Tattiyakul, J., Rao, M.A., Rheological bahavior of cross-linked waxy maize starch dispersion during and after heating (2000) Carbohydrate Polymers, 43 (3), pp. 215-222Tecante, A., Doublier, J.L., Steady flow and viscoelasti behaviour of crosslinked waxy corn starch κ-carrageenan pastes and gels (1999) Carbohydrate Polymers, 40 (3), pp. 221-231Vallés-Pàmies, B., The effects of low molecular weight additives on the viscosities of cassava starch (1997) Carbohydrate Polymers, 34 (1-2), pp. 31-38Wang, L., Wang, Y., Structure and physicochemical properties of acid-thinned corn, potato and rice starches (2001) Starch/Stärke, 53 (11), pp. 570-576Yamada, T., Morimoto, Y., Hisamatsu, M., Effects of citric acid on potato starch gelatinization (1986) Starch/Stärke, 38 (8), pp. 264-268Zobel, H.F., Molecules to granules: A comprehensive starch review (1988) Starch/Stärke, 40 (2), pp. 44-50