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

Abstract

The production of medium‐ and short‐grain rice in the mid‐Southern U.S. rice‐growing region is increasing. This work aimed to identify the quality traits of importance to the markets for these grain types. Twenty‐five medium‐ and short‐grain milled rice samples were collected and analyzed for physical, gelatinization, pasting, and starch structural properties. Six samples were from Arkansas (AR), five from California (CA), and 14 imported (IM). Cluster and principal component analyses showed that the AR samples had greater gelatinization temperature, enthalpy, and percentages of amylopectin long chains (B2 and B3 chains) but lesser kernel whiteness, total setback viscosity, and percentage of amylopectin short chains (A chains) than the CA samples. With the exception of one sample from Taiwan, chemometrics indicated that the IM samples differed from the AR samples (cluster A) in some properties and were grouped into three clusters (clusters B, C, and D). Cluster B samples had properties that were similar to the CA samples; cluster C samples had lower gelatinization temperature and peak viscosity but greater percentages of amylose and A chains than the AR samples; and cluster D samples had lesser paste breakdown but greater final viscosity and percentage of B1 chains than the AR samples. Kernel width, color, and chalk were the primary sources of variation in milled rice appearance. In relation to structure and functionality, the percentages of amylopectin A and B3 chains and amylose content were the major sources of variation.

Effect of Germination Conditions and Mashing Temperature on the Amylolytic Enzyme Activity and Degree of Starch Saccharification of Brown Rice Cultivars During Syrup Production

“…A strong positive correlation was found between apparent amylose content and gelatinization temperatures ( r = 0.95, P < 0.0001), supporting the findings of Varavinit, Shobsngob, Varanyanond, Chinachoti, and Naivikul () and Patindol et al. (). Tester and Morrison () and Park, Ibáñez, Zhong, and Shoemaker () suggested that more amylose–lipid complexes would be formed in starches of higher amylose contents, thus resulting in an initiation of swelling and gelatinization at higher temperatures.…”

“…The long-grain brown rice displayed the greatest onset, peak, and end gelatinization temperatures, whereas the waxy brown rice showed the lowest ones but the largest gelatinization temperature range, agreeing with results reported by Jane et al (1999). A strong positive correlation was found between apparent amylose content and gelatinization temperatures (r = 0.95, P < 0.0001), supporting the findings of Varavinit, Shobsngob, Varanyanond, Chinachoti, and Naivikul (2003) and Patindol et al (2016). Tester and Morrison (1990) and Park, Ibáñez, Zhong, and Shoemaker (2007) suggested that more amylose-lipid complexes would be formed in starches of higher amylose contents, thus resulting in an initiation of swelling and gelatinization at higher temperatures.…”

“…Thirty‐three grams of germinated brown rice flour were mixed with 100 mL of deionized water (33% w/v), and the slurry was incubated at 55, 65, 75, or 85 °C in a reciprocating water shaker bath (Boekel Scientific, Feasterville, PA, USA) at 80 rpm, and 1 mL of aliquot was taken periodically over a 24‐hr period. Five milliliters of 80% ethanol was immediately added to the aliquot to inactivate enzymes, the slurry was centrifuged, and the supernatant was used to determine the amount and composition of soluble saccharides with high‐performance anion‐exchange chromatography with pulsed amperometric detection (HPAEC‐PAD) according to the methods of Kasemsuwan, Jane, Schnable, Stinard, and Robertson () with modifications of Patindol, Jinn, Wang, and Siebenmorgen (). For the composition characterization by HPAEC‐PAD, the ethanol‐extracted aliquot was dried in an oven at 40 °C overnight and diluted to an appropriate concentration with Millipore water.…”

Understanding structure, functionality, and digestibility of faba bean starch for potential industrial uses

“…Branch-chain-length (BCL) distributions of the isolated starch samples were analyzed using high-performance anion-exchange chromatography equipped with pulsed amperometric detection (HPAEC-PAD) after debranching using isoamylase (Patindol et al, 2016). Starch (10 mg) was hydrated with 3.2 ml of deionized water, heated in a boiling water bath for 30 min with mild magnetic stirring, and cooled to room temperature (~23°C).…”