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

Abstract

Chemometric tests were carried out to better understand the multidimensional facet of starch fine structure-relationship concerning gelatinization and pasting properties. With Ward's hierarchical cluster analysis 20 long-grain rice starch samples were sorted out into three clusters based on similarities in functional properties, particularly, paste peak (PV) and final viscosity (FV). The three clusters (arbitrarily named Clusters A, B, and C) exhibited a pasting profile trend of PV,FV, PV,FV, and PV.FV, respectively. Cluster A samples were also lower in peak temperature, range and enthalpy of gelatinization, and swelling power. These attributes were associated with higher amylose content (AM), b-amylolysis limit, and percentage of B1 chains (DP13-24), but lower amylopectin weight-average molar mass (M w ) and percentage of A chains (DP6-12). A 5-variable linear discriminant function correctly predicted 85% of the Ward's cluster membership of the individual cultivars. The discriminant function included the variables A, B1, and B2 (DP25-36) chains, average chain length (ACL), and gyration radius (R z ). Fine structure variance was fully explained by a total of nine principal components, with the first three components cumulatively accounting for 74%. The leading variables included in the three rotated components pertained to amylopectin chain length distribution (A, B2, and B31 or DP!37 chains, and ACL) and amylopectin molar mass (M w , R z , and polydispersity). AM and M w were loaded most frequently in the 4-variable, best-fit linear regression models for predicting gelatinization and pasting properties. A combination of at least two fine structure variables controls the functionality of rice starch.

Kernel and Starch Properties of U.S. and Imported Medium‐ and Short‐Grain Rice Cultivars

“…7B), wherein AAC is loaded together with FV, SB, and TSB on the fourth quadrant, whereas BD was positioned oppositely on the second quadrant. The significant impact of amylose content on rice pasting characteristics has been extensively studied and reported by various authors (Patindol and Wang 2002; Bao et al 2007; Cameron et al 2007; Park et al 2007; Li et al 2008; Patindol et al 2009, 2014; Chávez‐Murillo et al 2011; Kong et al 2015). Present findings on AAC–pasting property relationships are in agreement with the literature, except that AAC did not correlate with PV.…”

“…The sample set used in this study may possess a unique combination of amylose‐amylopectin structural features so that the impact of amylose on PV was not clearly manifested. Previous chemometric analysis indicated that a combination of at least two fine structure variables dictated the functional properties of milled rice (Patindol et al 2009). Whereas some reports associate high GT and gelatinization enthalpy with high AAC (Patindol et al 2006; Park et al 2007; Li et al 2008; Chávez‐Murillo et al 2011), such a trend was not observed in the present study and may be attributed to the unique combination of amylose‐amylopectin structural features of the rice sample set used.…”

Thermal and rheological properties of granular waxy maize mutant starches after isoamylase modification

“…The supernatant was discarded, and the precipitate was re-dispersed in 6 mL of deionized water and then autoclaved at 121 • C for 15 min. After cooling, the sample was filtered through a 5.0-m membrane filter (mixed cellulose esters, SMWP, Millipore, Bedford, MA) prior to injection into a HPSEC-MALLS-RI system (HPSEC with multi-angle laser light scattering and refractive index detection) as described in Patindol, Gu, & Wang (2009). The coefficients of photodiode were standardized using a pullulan standard of 22,500 M w (Showa Denko K.K., Tokyo, Japan) as reference.…”

Comparison of amylopectin structure and activities of key starch synthesis enzymes in the grains of rice single-segment substitution lines with different Wx alleles

“…Prior to this study, a lot of researches have been expended on characterizing the relationship between amylopectin structure and starch physicochemical properties in rice (Han and Hamaker 2001;Nakamura et al 2002Nakamura et al , 2006Wang 2002, 2003;Patindol et al 2009). However, the results were not consistent since the rice samples and research methods used in previous studies were not the same.…”

“…Previous findings indicated that differences in physical behavior and functionality of rice starches are related to amylopectin structure (Han and Hamaker 2001;Nakamura et al 2002Nakamura et al , 2006Wang 2002, 2003;Satoh et al 2003;Fujita et al 2006Fujita et al , 2009Patindol et al 2009). Besides, there is no doubt that starch biosynthesis in rice endosperm involves the concerted actions of various types of biosynthetic enzymes.…”