Hui Sun

The effects of an industrial-scale microfluidizer (ISM) on the physicochemical properties and quality of whole-component dehulled foxtail millet slurry were investigated under varying processing pressures (0, 60, 90, and 120 MPa). ISM treatment significantly enhanced the apparent stability of the whole-component dehulled foxtail millet slurry, with ISM–120 exhibiting the best apparent stability. The results of dispersion characteristics, serum cloudiness, and zeta potential measurements indicated that ISM processing enhanced the physical stability of the slurry. As processing pressure increased, the particle size of whole-component dehulled foxtail millet slurry first decreased sharply and then showed a slight increase. Compared to the untreated slurry, the D was reduced by approximately 81.32%, 81.72%, and 78.44% after treatment at 60, 90, and 120 MPa, respectively. Concurrently, the apparent viscosity of the slurry rises with increasing processing pressure, with ISM–120 displaying the highest apparent viscosity. Furthermore, CLSM analysis revealed that ISM–90 and ISM–120 exhibited overall more uniform and stable structures. The content of damaged starch correspondingly increased with higher processing pressures, further corroborating the findings from particle size and scanning electron microscopy observations. Simultaneously, the soluble solids content also increased with rising ISM processing pressure. However, increasing ISM processing pressure progressively reduced the L*, a*, b*, and C* values of the slurry, while the ΔE and h values progressively increased. Compared to the untreated slurry, the ΔE value increased by approximately 1.92%, 3.85%, and 6.41% after treatment at 60, 90, and 120 MPa, respectively. These changes resulted in a deterioration of the color quality of the whole-component dehulled foxtail millet slurry.

Environmental factors significantly influence wheat grain quality by modulating starch biosynthesis and seed storage protein (SSP) composition, yet the underlying epigenetic mechanisms remain elusive. Here, we performed an integrated multi-omics analysis on the wheat cultivar ‘Fengdecunmai 5’ cultivated in two contrasting environments using WGBS, ChIP-seq (H3K27ac/H3K27me3), and RNA-seq. Epigenomic profiling revealed that environmental variation triggers extensive epigenetic reprogramming, with changes in H3K27ac enrichment being a primary epigenetic signature associated with the transcriptional divergence of starch and SSP biosynthesis genes during early development. Reconstruction of the transcriptional regulatory networks (TRNs) identified 86 essential transcription factors (TFs) that regulate 9,250 target genes in response to environmental impact. Our findings provide novel insights into the molecular basis of wheat quality instability across environments from an epigenetic perspective and highlight the critical role of histone modifications in regulating wheat seed quality.

With climate change, maintaining wheat quality has become essential for the functional properties, end-use, commodity value, and nutritional benefits of wheat flour. Temperature indirectly influences wheat quality by modulating grain size, starch and protein content, and the balance between these components. This review systematically analyzes temperature-mediated alterations in wheat grain quality, with particular emphasis on the two core components: starch and protein. Specifically, daytime warming generally increases protein content while reducing starch accumulation; however, temperatures exceeding 30 °C diminish key protein quality parameters (UPP%, Glu/Gli ratio, HMW-GS/LMW-GS ratio). Nighttime warming enhances protein quality but compromises starch content and yield potential. Conversely, under low-temperature conditions, starch content declines, whereas protein content is primarily influenced by genotypes and treated temperatures. Furthermore, the underlying mechanisms driving temperature-induced changes in wheat quality traits are discussed. However, the mechanisms of temperature effects have not been fully elucidated, and the results often vary between regions or over years. Thus, identifying conserved high/low-temperature resistance genes, QTLs, epialleles, and epiQTL, as well as developing corresponding molecular markers and epi-markers, is an urgent priority. Meanwhile, genome-editing tools such as CRISPR/Cas could serve as a powerful approach for creating new wheat germplasm with durable high/low-temperature resistance.

A large number of non-volatile metabolites are produced during the growth of rice; however, few studies have focused on the changes in these metabolites at different harvest times. In this study, Nangeng 5718 (a rice variety) was taken as the research object to study the changes in rice metabolites at different harvest times. Liquid chromatography mass spectrometry (LC-MS) was used to analyze the non-targeted metabolomics of rice at different harvest times in Nanjing, Huai’an, and Lianyungang in the Jiangsu Province of China. The results showed that 2111 metabolites were annotated by the human metabolome database (HMDB), accounting for 94.96% of the total number of metabolites. Rice metabolites included one categories, including 312 fatty acyls, 275 organooxygen compounds, 261 carboxylic acids and derivatives, etc. The results of the Kyoto encyclopedia of genes and genomes (KEGG) pathway showed that autophagy–other, ABC transporters, and glycerophospholipid metabolism had a great effect on rice heading to harvest. The experiments showed that L-histidine in Nangeng 5718 was upregulated. These results provide comprehensive insights into the relationship between rice harvest time and changes in metabolites.

Nitrogen is critical for rice yield and quality, but its overuse can be detrimental to efficiency and the environment. To identify changes in the quality of rice in response to the reduced application of nitrogen fertilizer, we carried out a comprehensive metabolomics study of SuiJing 18 using volatile metabolomics methods. Our results showed that SuiJing 18 had a total of 358 volatile metabolites, mainly lipids (16.25%), terpenoids (15.41%), heterocyclic compounds (15.13%), and hydrocarbons (13.45%). SuiJing 18 underwent significant changes in response to the reduced application of nitrogen fertilizer. Key sweet volatile compounds such as 4-methyl-benzeneacetaldehyde, hexyl acetate, and 2-methylnaphthalene were present at significantly higher levels when nitrogen fertilizer was applied at a rate of 68 kg of pure nitrogen per hectare, and their flavor characteristics also differed significantly from the compounds resulting from the other two treatments. Focusing on 16 differential volatile metabolites, we further investigated their effects on flavor and quality, thus laying the foundation for a greater understanding of the biomarkers associated with changes in rice quality. This study contributes to a better understanding of the mechanisms underlying changes in rice quality after reduced nitrogen fertilizer application.

Harvest time is very important to rice due to its high correlation to rice yield, eating quality, etc.; however, the impact of harvest time on quality is still unclear. In this study, Nangeng 5718, a japonica rice planted in three regions in Jiangsu Province of China, was used to analyze and compare the milling quality, appearance quality, and physicochemical quality of japonica rice at different harvest times. The results showed that the 1000-grain weight of Nangeng 5718 exhibited no significant change at different harvest times (p > 0.05). The brown rice rate and rice yield at different harvest times were 82.3–85.4% and 66.3–76.1%, respectively. Harvest time had no significant effect on the brown of rice (p > 0.05). However, Nangeng 5718 planted in Nanjing had the highest rice yield at 50 days after heading, which was significantly different from that of rice harvested 65 days after heading (p < 0.05). Nangeng 5718 planted in Huai’an had the highest rice yield at 55 days after heading, which was significantly different from that of rice harvested 60 days after heading (p < 0.05). Harvest time had little effect on the length, width, and thickness of rice. The immature grain rate showed a decreasing trend with the increase in maturity. There were little differences in the protein content of Nangeng 5718 at different harvest times. Nangeng 5718 planted in Nanjing had the highest protein content at 50 days after heading. There was a significant difference between the rice harvested and the rice harvested 60 days after heading (p < 0.05). There were no significant differences between the other two regions (p > 0.05). The accumulated temperature in Nanjing was relatively high, and the RVA curve and RVA eigenvalues of rice varied greatly. The setback value of rice harvested at 50 days was significantly lower than that at 55 days and 60 days (p < 0.05). Rice has good gelatinizing properties. Therefore, timely harvesting and appropriate accumulated temperature could increase 1000-grain weight and rice yield, reduce the immature grain rate, and improve the gelatinization characteristics. Overall, the quality of Nangeng 5718 reached a good level when it was harvested 50 days after heading, with the accumulated temperature reaching 1051 °C. In fact, the harvest time should be chosen flexibly according to the weather conditions. Nangeng 5718 planted in Nanjing should be harvested earlier than 50 days, and rice from Huai’an and Lianyungang was of better quality when the harvest time was 50 days.