Gelatinization and Pasting Properties of Waxy and Non‐waxy Rice Starches

Abstract

Gelatinization and pasting properties of diverse rice types grown in two locations were examined by differential scanning calorimetry (DSC) and rotational rheometry, respectively. The data were compared to previously reported molecular starch properties for these samples: specifically, amylose content, starch molecular weight (M w ), and amylopectin side-chain-length distributions. Significant correlations were observed between amylose content, starch M w , and the weight degree of polymerization of the long side chains of amylopectin F 1 (DP w ) and many of the gelatinization and pasting properties measured. Higher amylose content corresponded with increased gelatinization onset (T o ) and peak temperatures (T p ), pasting onset and peak temperatures, and decreased peak and trough viscosity. Starch M w correlated negatively with T o , T p , pasting onset, and peak temperature and positively with peak, trough, final, and breakdown viscosity. Amylopectin with DP w 59-78 of F 1 (DP w ) correlated with increased T o , T p , pasting onset and peak temperature, and decreased peak, trough, final and breakdown viscosity. Pasting properties were also somewhat related to DP w 21 of shorter side chains of amylopectin (F 2 (DP w )). Significant correlations between F 2 (DP w ) and peak, final, and breakdown viscosity were observed (r = 20.447*, 20.391*, 20.388*, peak, final, and breakdown viscosity, respectively).

Chemometric Analysis of the Gelatinization and Pasting Properties of Long‐grain Rice Starches in Relation to Fine Structure

“…The role of amylose and amylopectin in the gelatinization and pasting properties of rice starch has been widely studied [2,[5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Starch swells irreversibly and its crystalline structure collapses when heated in excess watera phenomenon known as gelatinization.…”

“…Starch swells irreversibly and its crystalline structure collapses when heated in excess watera phenomenon known as gelatinization. Starch swelling is a property of amylopectin [5], whereas, amylose has been known to restrict it [5][6][11][12][13][14][15][16]. Restricted starch granule swelling results in a lower peak paste viscosity based on measurements with a Brabender Viscoamylograph or a Rapid Visco Analyser [6][7][8][9][10][11][12][13][14][15][16][17].…”

“…Starch swelling is a property of amylopectin [5], whereas, amylose has been known to restrict it [5][6][11][12][13][14][15][16]. Restricted starch granule swelling results in a lower peak paste viscosity based on measurements with a Brabender Viscoamylograph or a Rapid Visco Analyser [6][7][8][9][10][11][12][13][14][15][16][17]. Paste breakdown correlates positively with the proportion of short amylopectin chains, negatively with long chains [6][7][12][13][14], and also negatively with amylose content [6,14,17].…”

“…Double helices from amylopectin long chains require higher temperature for complete dissociation than those from short chains [21]. Literature also associates high temperature and enthalpy of gelatinization with high amylose content [6,14,15,17].…”

Characterization and Utilization of Starches Extracted from Florencia and Waxy Maize Hybrids for Tablet Formulation: Compaction Behaviour and Tablet Properties

“…According to the literature, waxy maize starch is an appropriate candidate for the production of biodegradable plastics [9] [10]. Starch and its modifications play a prominent role in pharmaceutical formulations used as disintegrants, fillers, binders and gel/film-forming polymers [12]- [17]. Waxy starches largely composed of amylopectin have been reported to act more effectively in controlled drug release and mucoadhesive drug formulations than native starches [18]- [22] due to the fact that the intramolecular hydrogen bonds between the amylopectin chains stabilize the matrix structure of the tablet.…”