Optimizing Instant Rice Quality of Milled and Brown Rice Through Cultivar‐Selection
Faith Ouma, Kaushik Luthra, Griffiths AtunguluABSTRACT
Background and Objectives
Instant rice products are increasingly favored for convenience; however, achieving consistent quality, particularly rehydration performance and texture, remains a challenge. Rice cultivars differ in physicochemical properties that influence processing behavior and final product quality, yet systematic screening approaches for instant rice optimization are limited. This study evaluated the instantization potential of 25 rice cultivars (hybrid and pureline; medium and long grain) in milled and brown forms to identify those most suitable for instant rice processing. Parameters measured included amylose and protein contents, gelatinization temperature (GT), cooking duration (CD), percentage point moisture removal (ΔMC %), texture, rehydration ratio, volume increase ratio (VIR), bulk density, whiteness index, and water activity ( a w ).
Findings
Cultivar and grain form (milled vs. brown) influenced nearly all instant rice quality attributes ( p < 0.05). Breeding type was not a major main effect for instant rice quality except through a grain form‐breeding type interaction that affected ΔMC (%) during stepwise hot‐air drying (SHAD) ( p < 0.05). Brown instant rice showed lower rehydration and VIR but greater hardness than milled instant rice. Principal component analysis (PCA) explained 61.4% of the variance in milled instant rice quality and 48.5% in brown. Based on multi‐attribute optimization, X16 (long‐grain hybrid) and Y3 (long‐grain pureline) were identified as the top‐performing cultivars among milled and brown rice, respectively (actual names are coded). Cultivars Y5 and Y6 (medium‐grain pureline) underperformed in key quality traits across both grain forms (actual names are coded).
Conclusions
These findings indicate that instantization performance depended more on cultivar and grain form than breeding type. Overall, screening results demonstrated clear cultivar differences in instantization performance for both milled and brown rice forms.
Significance and Novelty
These results provide practical guidance for processors in selecting cultivars with favorable physicochemical profiles to produce instant rice with improved and more consistent quality. Cultivar selection is often based primarily on agronomic performance and milling yield, whereas processing suitability receives less attention.