Identifying Arkansas Rice Cultivars With Similar Physicochemical Attributes and Milling Performance

Abstract

Background and Objectives

The objective of this study was to comprehensively evaluate the variation in milling efficiency and physicochemical attributes among Arkansas rice cultivars. To accomplish this, a total of 45 cultivars were analyzed, including 9 long-grain purelines, 32 long-grain hybrids, 2 medium-grain purelines, and 2 medium-grain hybrids collected over three harvest seasons from 2019 to 2022. Hierarchical clustering and principal component analysis (PCA) were employed to identify and classify groups of cultivars with similar characteristics, and to generate components that capture most of the variability across the explored variables, using the 30-s milling and the area under the curve (AUC) of 0–60 s milling summary. The samples were assessed for key quality parameters, including moisture content, field fissuring, total protein content, chalkiness, kernel dimensions, total lipid content, milling yields, color, and pasting properties. By examining this diverse range of cultivars under controlled conditions, the study aims to better understand the genetic and environmental factors influencing variations in rice quality.

Findings

Hierarchical clustering based on rice quality parameters after 30 s of milling grouped the cultivars into five clusters, with Groups 1–4 comprising long-grain types and Group 5 consisting entirely of medium grains. This distinction is expected given the differences in milling behavior between medium- and long-grain cultivars due to morphological traits. PCA score plots showed that medium grains were strongly associated with kernel width, milled rice yield (MRY), and peak viscosity, while cultivars such as RTv7303, V3503, RT7801, V3502, and XP784 were correlated to higher setback and final viscosities. Similarly, clustering based on the AUC summary dataset produced four groups, again isolating medium grains. In this analysis, medium grains were correlated with higher width, MRY, head rice yield (HRY), and NIR color b-values.

Conclusions

In conclusion, Jupiter, RT302, RT3201, and Titan consistently emerged as a distinct group across the rice quality properties, providing valuable information to millers, breeders, and producers to identify rice cultivars with similar milling behavior and physicochemical properties.

Significance and Novelty

The results from this study support the selection of suitable cultivars for product formulation by clearly identifying which cultivars share similar physical, milling, and functional properties. By grouping cultivars with comparable characteristics, the findings help formulators choose rice types that will perform reliably in specific processing or end-use applications. This information also helps in identifying potential substitutes when a preferred cultivar is unavailable and enables better commingling strategies to maintain consistency and improve overall product quality.