Differences in rice component distribution across layers and their relationship with taste.

Background: Rice taste is closely associated with endosperm composition, which varies among different rice layers. Although clarifying the relationship between this difference and nutritional taste can guide rice breeding and cultivation practices, research on this topic is limited.
Results: Here, typical rice varieties having excellent and poor taste characteristics were selected to analyze the distribution characteristics and differences of their components. The varieties with excellent taste exhibited lower apparent amylose content (AAC) and protein content (PC), lesser short-chain (Fa) and long-chain (Fb ₃ ) amylopectin (AP) and more medium-chain (Fb ₁₊₂ ) AP, higher long-to-short chain ratio (Fa:Fb ₃ ), and higher nitrogen (N), magnesium (Mg) and calcium (Ca) content in layer 1 (L1) than the varieties with poor taste. Layer 2 (L2) played a key role in AAC and PC regulation in the varieties with excellent taste by reducing AAC and appropriately increasing PC, consequently improving rice taste. AP structure in layer 3 (L3) substantially affected the taste of the two types of varieties. The mineral content was the highest in L1, and increased potassium (K), Ca, and Mg content improved taste in all varieties.
Conclusion: AAC in each layer contributes to rice taste. PC and minerals primarily act on L1 and L2, whereas AP acts on L2 and L3. Therefore, the endosperm formation process should be exploited for improving rice taste. Furthermore, key resources and cultivation should be identified and regulated, respectively, to improve rice taste. © 2023 Society of Chemical Industry.
(© 2023 Society of Chemical Industry.)