Effect of superfine grinding chestnut powder on the structural and physicochemical properties of wheat dough

This study evaluated the influence of chestnut powder, produced using ball mill superfine grinding (BMSG), jet superfine grinding (JSG), and ordinary grinding (OG), on wheat flour properties. Blending wheat flour with chestnut powder resulted in a darker flour blend (3 % decline of L*), with decreased the tap density and increased water holding capacity. Adding appropriate proportion of superfine chestnut powder can bolster the mixed flour's thermal stability (15 % BMSG/JSG) and freeze-thaw stability (10 % BMSG/JSG), while significantly enhancing the anti-aging properties of flour products. The proposition of 5 % superfine BMSG/JSG did not significantly affect the tensile resistance of the dough, and even improve the dough's tensile strength. In addition, the hardness, adhesiveness, springiness and pH of fermentation increased due to the addition of chestnut powder, as supported by the dough texture analyses and fermentation characteristics findings. However, the excessive addition of chestnut powder affected the dough network's structural integrity to some extent. Further study can focus on the influencing mechanism of chestnut powder on gluten formation and related nutritional properties. Overall, this research underscores the potential of utilizing chestnut powder to enhance the nutritional and functional qualities of wheat-based products.

Transcriptome Sequencing and Differential Expression Analysis Reveal Molecular Mechanisms for Starch Accumulation in Chestnut

Chestnuts are popular edible nuts that are rich in starch. In order to enhance the transcriptomic resources and further understand starch and sucrose metabolism in maturing chestnuts, a comparative transcriptomic study of Chinese chestnut kernels was conducted at three ripening stages (70, 82, and 94 DAF). At 82 and 94 days after flowering (DAF), starch continued to accumulate, and the amylopectin/amylose ratio increased. Transcriptomic profiling of kernels at 70 (stage I), 82 (stage II), and 94 DAF (stage III) indicated that soluble starch synthase and α-1,4-glucan branching enzyme genes are actively expressed at 82 and 94 DAF. The starch degradation enzymes amylase, phosphoglucan phosphatase DSP4, and maltose exporter did not show differential gene expression, while glycogen phosphorylase-encoding unigenes were significantly down-regulated at 94 DAF. In addition to starch and sucrose metabolism, RNA transport, RNA degradation, pyrimidine metabolism, purine metabolism, plant hormone signal transduction, plant–pathogen interactions, and glycerophospholipid metabolism were found to be significantly enriched in all comparisons included in the study. As Chinese chestnut matured, the unique enriched pathways switched from ribosomal biogenesis and RNA polymerase of eukaryotes to endocytosis and spliceosomes. These genomic resources and findings are valuable for further understanding starch and sucrose metabolism in the Chinese chestnut.

Phytochemical Profiles and Cellular Antioxidant Activities in Chestnut (Castanea mollissima BL.) Kernels of Five Different Cultivars

In this study, the phytochemical profiles, total and cellular antioxidant activities of five different Chinese chestnut (Castanea mollissima BL.) cultivars were analyzed. Phenolics, flavonoids as well as phytochemical compounds in five cultivars of chestnut kernels were determined. Results showed that the free forms played a dominant role in total phenolics, flavonoids and antioxidant activities of all five cultivars of chestnut kernels. The cultivar ‘Fyou’ showed the highest total and free phenolic contents, ‘Heguoyihao’ showed the highest total and free flavonoids contents, and ‘Chushuhong’ showed the highest total and cellular antioxidant activities. Eight phenolic compounds were detected, and chlorogenic acid, gallic acid, and quercetin were shown as three predominant components in all five cultivars. These results provide valuable information which may be a guidance for selection of good chestnut variety to be used as functional food.

Effect of Steaming Processing on Phenolic Profiles and Cellular Antioxidant Activities of Castanea mollissima

The intention of this study was to investigate the effect of steaming processing on phenolic profiles and antioxidant activities in chestnuts. Steaming processing at different times and temperatures depicted diverse impacts on free and bound fractions. Though, bound phenolics were stable but long time steaming at higher temperatures tended to improve the levels of phenolics, flavonoids as well as antioxidant activities in chestnut kernels, by up to 60.11% of the original value. Seven phenolic compounds including ferulic acid, chlorogenic acid, gallic acid, vanillic acid, syringate, p-coumaric acid and quercetin were found to change during thermal processes. Significant relationships (p < 0.05) were identified between total phenolics and total antioxidant activities. However, the consistency of chlorogenic acid (p < 0.01) only with cellular antioxidant activity indicated poor bio-accessibility of the phytochemicals in chestnuts. However, this situation could be partly improved by steaming. Steaming could improve the cellular accessibility of free phytochemicals, particularly, increasing the bio-accessibility by 41.96%. This study provided valuable information on dynamic changes of phenolic profiles and antioxidant activity of chestnuts under a steaming process, which could offer possible guidance for the chestnut processing industry in the future.