Structural and Physicochemical Characteristics of Lintnerized Native and Sour Cassava Starches

Abstract

The comprehension of the structure of starch granules is important for the understanding of its physicochemical properties. Native and sour cassava starches after being analyzed with respect to their pasting properties and baking expansion capacity, were treated with 2.2 N HCl at 38 °C for a maximum of nine days. The starch granules remaining after lintnerization were analyzed for amylose content and intrinsic viscosity, by X-ray diffraction, scanning electron microscopy and chromatographic analysis. The results indicated that the acid hydrolysis on all starches occurred in two steps. The first one, with high hydrolysis rate, was characterized by a quick degradation of the amorphous part of the granules whereas the second step, with lower hydrolysis rate, was characterized by a higher resistance of the organized areas of the granules to acid treatment. Most of the amylose chains were found in the amorphous areas of starch granules only a small percentage was involved in the crystalline regions. The microscopic and chromatographic analysis demonstrated that the acid hydrolysis was not able to disrupt the entire granular crystalline structure. Fermented starch showed amylose and/or amylopectin chain fractions resistant to pullulanase, probably due to structural alterations during fermentation.

Effect of lactic acid and UV irradiation on the cassava and corn starches

“…The rolls prepared with native cassava and corn starches did not show baking expansion capacity, presenting very low specific volumes (2.35 and 1.21, respectively for cassava and corn starches). The rolls prepared with both the commercial sour cassava starch samples presented an inflated appearance, a crumb with typical flavor and alveolar structure, crispy crust and high specific volume (12.10 and 13.05 cm 3 /g), as expected (Franco et al, 2002a). From the samples treated with lactic acid and UV-light, only the rolls prepared with modified cassava starch showed baking expansion ability (8.08 cm 3 /g), presenting appearance and texture similar to those shown by the commercial sour cassava starch samples.…”

“…It is used as basis for biscuit or cheese bread dough, both without using wheat flour, yeast or baking power (Westby and Cereda, 1994). The dough expansion occurs during baking and the baked products present an inflated appearance with good internal alveolar structure (Camargo et al, 1988;Dufour et al, 1996;Demiate et al, 2000;Franco et al, 2002a). Similar to the breads made by traditional bakery process, the products made with sour cassava starch present, in its interior, a gelatinized starch matrix, responsible for its expansion and texture.…”

Comparative Studies on Some Physico-chemical, Thermal, Morphological, and Pasting Properties of Acid-thinned Jicama and Maize Starches

“…According to Atichokudomchai et al (2000) when increasing the hydrolysis time from 12 to 96 h, an exposed corrosion on the surface of the granules is observed, which is not observed with low hydrolysis times similar to those observed for native starches. Franco et al (2002) did not find any difference in the external structure of commercial native cassava starch and commercial fermented cassava starch hydrolyzed with 2.2N HCl at 38°C. However, observation under a scanning electron microscope exposed fissures in the granules.…”

Influence of nitrogen fertilization on the characteristics of potato starch

“…Starch samples were defatted by dispersing in 90% DMSO solution, and the resulting mixtures were boiled and stirred for 1 h (Franco et al, 2002). Iodine affinities of defatted whole starches were determined according to the methods described by Kasemsuwan et al (1995) using a potentiometric autotitrator (716SM Titrino, Brinkmann Instrument, Westbury, NY).…”