Physico‐Chemical Properties of Defatted Heat‐Moisture Treated Starches

Abstract

Physico-chemical properties of wheat-and potato starch, defatted before or after heat-moisture treatment, were compared with those of untreated starches. Effects on waterbindingcapacity, swelling power, solubility, enzyme susceptibility, gelatinization temperature range, viscograph consistency and on functional properties such as cake baking performance and thickening power are reported. X-ray diffraction patterns of samples defatted before heating appeared slightly sharper than those of non-defatted, then heatmoisture treated samples. Defatting of wheat starch combined with heat-moisture treatment caused less reduction in relative crystallinity than heat-moisture treatment alone, enzyme susceptibility was reduced, viscograph consistencies increased and cake baking performance and thickening power of the starches improved. Defatting of potato starch combined with heat treatment had some positive effects on enzyme susceptibility, solubility and thickening power. Physikalisch-chemische Eigenschaften von entfetteten hitze-feuchtigkeitsbehandelten Starken. Die physikalisch-chemischen Eigenschaften von Weizen-und Kartoffelstarke, die vor oder nach der Hitze-Feuchtigkeitsbehandlung entfettet worden waren, wurden mit denen von unbehandelten Starken verglichen. Die Einflusse auf Wasserbindungsvermogen, Quellvermogen, Loslichkeit, Angreifbarkeit durch Enzyme, Verkleisterungstemperatur, viskographische Konsistenz und funktionelle Eigenschaften wie Backverhalten bei Kuchen und Dickungsvermogen werden mitgeteilt. Das Rontgenbeugungs-Diagramm der vor der Entfettung erhitzten Proben erschien etwas schiirfer als das der nicht entfetteten hydrothermisch behandelten Proben. Die Entfettung von Weizenstarke in Kombination mit hydrothermischer Behandlung verursachte geringere Reduzierung der relativen Kristallinitat als die Hitze-Feuchtigkeitsbehandlung allein ; die enzymatische Angreifbarkeit wurde reduziert, die viskographische Konsistenz erhoht, und das Kuchenbackverhalten sowie das Dickungsvermogen wurden verbessert. Die Entfettung von Kartoffelstarke in Verbindung mit Hitzebehandlung hatte einige positive Auswirkungen auf enzymatische Angreifbarkeit, Loslichkeit und Dickungsvermogen.

A Review of Rice Starch Digestibility: Effect of Composition and Heat‐Moisture Processing

“…However, the impact is dependent on the type of starch to which the treatments are applied. Heat‐moisture treatment at 110 °C with 15, 20 and 25% moisture decreases crystallinity and increases α‐amylase susceptibility of rice starch, similar to what has been found with wheat and potato . However, heating corn starch to 110 °C with 20, 25, 30 and 35% moisture increased crystallinity and decreased in vitro digestibility .…”

“…Heat‐moisture treatment such as parboiling, cooking, annealing and extrusion (Table ) reduces starch crystallinity . During heat‐moisture processing, starch undergoes gelatinisation, a complex process of irreversible disruption of the double helical crystalline structure of starch (Figure ).…”

Digestibility and Pasting Properties of Rice Starch Heat-Moisture Treated at the Melting Temperature (Tm )

“…The increase in digestibility by amylase after heat-moisture treatment suggests a change in orientation of the starch polymers in the granules by the treatment followed by a certain degree of degradation which rendered the starch more accessible to amylase, as previously report- ed [9]. Digestibility increases in the heated starches may also be attributed to gelatinization of starch, characterized by irreversible swelling of the granules, increase in viscosity as the order and crystallinity of the starch molecules are broken down by heat allowing more water penetration and hydration of the granules [16].…”

“…Heat-moisture treatment of wheat starch caused a considerable reduction in relative crystallinity and resulted in increased enzyme susceptibility [9]. Secondly, it has been observed that the dehydration which accompanies heatmoisture treatment of starch changes the crystallographic pattern of the starch granules leading to the conversion of a fraction of amorphous amylose to the crystalline form [9].…”

“…Secondly, it has been observed that the dehydration which accompanies heatmoisture treatment of starch changes the crystallographic pattern of the starch granules leading to the conversion of a fraction of amorphous amylose to the crystalline form [9]. The consequences of such conversion include the reduction in solubility and swelling and the stabilization of the starch granules.…”