Ascorbic acid (AsA) and carotenoids are recognized as crucial metabolites for various biological processes in plants. The contents of AsA and carotenoids in fruits are influenced by external environmental stimuli, such as water, temperature, light, and hormones. However, it is still not clear whether it can be affected by root restriction (RR) treatment. In this study, “Summer Black” grape berries (Vitis vinifera × V. labrusca) under RR and control treatments during development and ripening were used as materials. The results showed that RR significantly increased the contents of AsA, and the transcript VIT_08s0040g03150 related to AsA recycling pathways may be the main regulator for AsA. Similarly, the contents of most of the carotenoids at the earlier stages significantly increased by RR; the enzyme crtB encoded by VIT_12s0028g00960 and the enzyme crtZ encoded by VIT_02s0025g00240 and VIT_16s0050g01090 were inferred to play major roles in the carotenoid metabolic pathways.Keywords: ascorbic acid; carotenoid; grape berry; RNA-Seq; root restriction;

Oxidative stress and diabetes have a tendency to alter protein, lipid, and DNA moieties. One of the strategic methods used to reduce diabetes-associated oxidative stress is to inhibit the carbohydrate-digesting enzymes, thereby decreasing gastrointestinal glucose production. Plant-derived natural antioxidant molecules are considered a therapeutic tool in the treatment of oxidative stress and diabetes. The objective of this study was to identify tartary buckwheat rice flavonoids and evaluate the effect of in vitro digestion on their antioxidant and antidiabetic properties. High performance liquid chromatography (HPLC) analysis indicated the presence of rutin as a major component and quercitrin as a minor component of both digested and non-digested flavonoids. Both extracts showed a significant antioxidant capacity, but digested flavonoids showed reduced activity compared to non-digested. There were some decreases of the antioxidant activities (2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS), 2,2-diphenyl-1-picrylhydrazy (DPPH) radical, and ferric reducing antioxidant power (FRAP)) of digested tartary buckwheat rice flavonoids compared with non-digested. Flavonoids from both groups significantly inhibited reactive oxygen species (ROS) production and α-glucosidase activity. Both digested and non-digested flavonoids markedly increased glucose consumption and glycogen content in HepG2 cells. Tartary buckwheat rice flavonoids showed appreciable antioxidant and antidiabetic properties, even after digestion. Tartary buckwheat rice appears to be a promising functional food with potent antioxidant and antidiabetic properties.研究黑苦荞米黄酮模拟消化前后活性成分含量 变化, 以及模拟消化对其抗氧化及降血糖活性的 影响。采用体外模拟消化的方法, 更加真实地反应消化 对黑苦荞米黄酮含量及活性的影响, 同时采用体 外抗氧化方法、α-葡萄糖苷酶实验和HepG2 细 胞模型, 评价其抗氧化和降血糖活性。本文采用体外模拟消化的方法, 对黑苦荞米黄酮 进行模拟消化, 使用高效液相色谱(HPLC)检测 其消化前后黄酮物质含量变化情况(表1 和图1); 通过ABTS、DPPH 和FRAP 等实验研究模拟消 化对其抗氧化活性的影响(表2 和图2), 进一 步检测其消化前后对细胞活性氧(ROS)产生的 抑制能力(图3);利用α-葡萄糖苷酶活性抑制 实验(图4)以及细胞葡萄糖消耗和糖原含量实 验(图5), 评价黑苦荞米黄酮模拟消化前后的 降血糖活性。HPLC 结果表明, 黑苦荞米黄酮中的主要活性物 质为芦丁和槲皮苷, 经模拟消化后, 其活性物质 含量没有显著变化。体外抗氧化实验ABTS、 DPPH 和FRAP 结果均表明, 黑苦荞米黄酮具有 抗氧化活性, 体外模拟消化后, 其抗氧化活性有 所降低;细胞ROS 结果表明, 黑苦荞米黄酮模 拟消化前后均具有较好的ROS 抑制活性。进一 步研究表明, 黑苦荞米黄酮模拟消化前后对α- 葡萄糖苷酶具有较好的抑制能力, 同时可以促进 细胞对葡萄糖的消耗以及细胞糖原的生成, 具有 较好的降血糖活性。

•The phenolics profile of four cherry species was determined.•Quantification of phenolics was carried out.•The physicochemical characteristics of four cherry species were compared.The physicochemical characteristics of four cherry species (Prunus avium, Prunus cerasus, Prunus pseudocerasus and Prunus tomentosa) were evaluated. Inter-species variability was greater than intra-species differences. Glucose and fructose were the main sugars, and malic acid was the main organic acid in all species. Combining HPLC-DAD and LC–ESI-MS/MS technologies, total 25 phenolic components were preliminarily identified. P. avium was characterised by high fruit weight, edible proportion, sugar content and low acid content, which made it suitable for fresh eating. P. cerasus was high in acid content and anthocyanins content, making it a good processing species. P. pseudocerasus had rich flavonols varieties and high proportion of hydrocinnamic acids. P. tomentosa was characterised by high total phenolics content (especially flavonols and tannins) and antioxidant activity, indicating a great developmental potential as a health fruit. The results of the present study might provide theoretical guidance for the further development and utilisation of cherries.

Organic acids as well as soluble sugars contribute highly to flavor and overall quality of citrus fruit. Citric acid level in fruit is influenced by several factors including environmental conditions. In this study, it was observed that different environments in two habitats (Ganzhou, Jiangxi; Songyang, Zhejiang) had minor effects on total soluble solids and citrus color index but had significant effects on organic acids levels, particularly on citric acid level, in fruit of “Newhall” and “SkaggsBonanza” navel oranges (Citrus sinensis). Expression of genes involved in citric acid biosynthesis and degradation (CitCS1, CitCS2, CitAco1, CitAco2, CitAco3, CitIDH1, CitIDH2, CitIDH3, CitGAD4, CitGAD5, and CitGS2) was analyzed in fruit grown in each of the two habitats. Citric acid biosynthesis-related citrate synthase genes were steadily expressed during navel orange fruit development, while degradation-related genes were differentially expressed. These findings suggested that the influence of different environments on fruit quality traits was predominant on the regulation of organic acids level, particularly on the degradation of citric acid. A cascade of CitAco3–CitIDH1–CitGS2 might be involved in citric acid degradation in response to different environments during fruit growth and development.

Total phenolics, flavonoids, anthocyanins, cyanidin-3-O-glucoside (Cy-3-glu) and antioxidant capacity of Chinese bayberry fruit (Myrica rubra Sieb. and Zucc.) differed among the four cultivars “Baizhong” (white), “Fenhong” (pink), “Wuzhong” (red) and “Biqi” (dark red). Antioxidant capacity determined by both the ferric reducing antioxidant power (FRAP) assay and 2,2-diphenyl-2-picrylhydrazyl (DPPH.) radical scavenging capacity was significantly correlated with the antioxidant components in the fruit, and directly related to fruit color. Cy-3-glu accounted for at least 82, 38, and 12% of the total antioxidant capacity in “Biqi”, “Wuzhong” and “Fenhong” fruits, respectively. No detectable Cy-3-glu was found in “Baizhong” fruit. Greater fruit maturity was associated with higher levels of all the bioactive components and antioxidant capacity. Significant increases were also found during postharvest storage of “Biqi” fruit held at either 20 °C for 2 days or 0 °C for 5 days. However, these levels decreased during a 2-day shelf-life at 20 °C after 5 days at 0 °C. These results show that storage and shelf-life conditions are important if health-based bioactive components of bayberry fruit are to be maintained after harvest.