Gel Consistency in Rice: Genetic Mechanisms, Starch Properties, and Culinary Quality – A Comprehensive Review

Abstract

Gel consistency (GC) is the vital deciding factor of cooked rice texture together with consumer preference that is strongly predisposed by genetic, environmental, and procedural effects. The most recent developments that are synthesized in the current review show that GC is highly affected by the Waxy (Wx) gene and quantitative trait loci (QTLs) that mediate the production of amylose, the mechanization of which indicates that softer texture is linked with low levels of amylose which is subsequently associated with higher GC. Environmental modulation is high: overuse of nitrogen fertilizers increases amylose levels, or toughens texture and deficient water leads to the decrease of GC; the optimal alternative wetting and drying (AWD) irrigation, however, increases the levels of GC. Methodological instruments, such as the Alkali Spreading Value (ASV) and the Rapid Visco Analyzer (RVA), can be used to give objective and quantitative measures of the physicochemical properties, and these are supplemented by sensory and rheological investigations, which relate the metrics to perception by the consumer. There is strong cultivar divergence: indica types tend to have harder GC, which is suited to cooking in South Asia, japonica types have softer GC, and is appropriate in East Asia, an indication of the genotype-by-environment interaction. High-GC rice has a high market value of culinary uses, but hard-GC is not accepted in the market. Attention should be focused on combined genotypic-environment stability, resource sustainability, nutritional quality, in order to fulfill emerging consumer and climatic needs.