Preparation and functional properties of rice bran globulin-chitooligosaccharide-quercetin-resveratrol covalent complex.

BACKGROUND: As the major protein (approximately 36%) in rice bran, globulin exhibits excellent foaming and emulsifying properties, endowing its useful application as a foaming and emulsifying agent in the food industry. However, the low water solubility restricts its commercial potential in industrial applications. The present study aimed to improve this protein's processing and functional properties. RESULTS: A novel covalent complex was fabricated by a combination of the Maillard reaction and alkaline oxidation using rice bran globulin (RBG), chitooligosaccharide (C), quercetin (Que) and resveratrol (Res). The Maillard reaction improved the solubility, emulsifying and foaming properties of RBG. The resultant glycosylated protein was covalently bonded with quercetin and resveratrol to form a (RBG-C)-Que-Res complex. (RBG-C)-Que-Res exhibited higher thermal stability and antioxidant ability than the native protein, binary globulin-chitooligosaccharide or ternary globulin-chitooligosaccharide-polyphenol (only containing quercetin or resveratrol) conjugates. (RBG-C)-Que-Res exerted better cytoprotection against the generation of malondialdehyde and reactive oxygen species in HepG2 cells, which was associated with increased activities of antioxidative enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) through upregulated genes SOD1, CAT, GPX1 (i.e. gene for glutathione peroxidase-1), GCLM (i.e. gene for glutamate cysteine ligase modifier subunit), SLC1A11 (i.e. gene for solute carrier family 7, member 11) and SRXN1 (i.e. gene for sulfiredoxin-1). The anti-apoptotic effect of (RBG-C)-Que-Res was confirmed by the downregulation of caspase-3 and p53 and the upregulation of B-cell lymphoma-2 gene expression. CONCLUSION: The present study highlights the potential of (RBG-C)-Que-Res conjugates as functional ingredients in healthy foods. © 2024 Society of Chemical Industry.

Restoration of Cullin3 gene expression enhances the improved effects of sonic hedgehog signaling activation for hypertension and attenuates the dysfunction of vascular smooth muscle cells.

BACKGROUND: Hypertension is known as a major factor for global mortality. We aimed to investigate the role of Cullin3 (CUL3) in the regulation of hypertension. MATERIAL AND METHODS: Human vascular smooth muscle cells (VSMCs) were treated with Angiotensin II (Ang II) to establish a hypertension in vitro model. Cell viability was detected by a cell counting kit-8 (CCK-8) assay. The content of reactive oxygen species (ROS) was evaluated by kit. Transwell assay and TUNEL staining were, respectively, used to assess cell migration and apoptosis. Additionally, the expression of sonic hedgehog (SHH) signaling-related proteins (SHH, smoothened homolog (Smo) and glioblastoma (Gli)) and CUL3 was tested with western blotting. Following treatment with Cyclopamine (Cycl), an inhibitor of SHH signaling, in Ang II-induced VSMCs, cell viability, migration, apoptosis and ROS content were determined again. Then, VSMCs were transfected with CUL3 plasmid or/and treated with sonic hedgehog signaling agonist (SAG) to explore the impacts on Ang II-induced VSMCs damage. In vivo, a hypertensive mouse model was established. Systolic blood pressure and diastolic blood pressure were determined. The histopathologic changes of abdominal aortic tissues were examined using H&E staining. The expression of SHH, Smo, Gli and CUL3 was tested with western blotting. RESULTS: Significantly increased proliferation, migration and apoptosis of VSMCs were observed after Ang II exposure. Moreover, Ang II induced upregulated SHH, Smo and Gli expression, whereas limited increase in CUL3 expression was observed. The content of ROS in Ang II-stimulated VSMCs presented the same results. Following Cycl treatment, the high levels of proliferation and migration in Ang II-treated VSMCs were notably remedied while the apoptosis and ROS concentration were further increased. Moreover, Cycl downregulated SHH, Smo, Gli and CUL3 expression. Above-mentioned changes caused by Ang II were reversed following SAG addition. Indeed, SAG treatment combined with restoration of CUL3 expression inhibited proliferation, migration, apoptosis and ROS level in Ang II-stimulated VSMCs. In vivo, SAG aggravated the histopathological changes of the aorta and with a worse tendency after both SAG intervention and CUL3 silencing. By contrast, SAG treatment and rebound in CUL3 expression alleviated the vascular damage. CONCLUSIONS: Collectively, restoration of CUL3 gene expression protected against hypertension through enhancing the effects of SHH activation in inhibition of apoptosis and oxidative stress for hypertension and alleviating the dysfunction of VSMCs.

Association of gut microbiota characteristics and metabolites reveals the regulation mechanisms under cadmium consumption circumstance.

BACKGROUND: Cadmium is a non-biodegradable heavy metal with a long biological half-life. Although its negative impact on human health has been previously reported, the association of cadmium consumption overdose with changes in the gut microbiota and its corresponding metabolites has not been fully elucidated so far. RESULTS: Cadmium consumption overdose led to a reduced body weight gain accompanied by an enhanced level of the proinflammatory cytokine tumor necrosis factor-α, interleukin-6, and histamine in the serum of the rats in comparison with normal rats. Furthermore, hepatotoxicity was also observed to be induced by cadmium, which was consistent with abnormal hepatic activities of alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase and oxidative stress. In contrast, Lactobacillus rhamnosus-fermented Ganoderma lucidum (FGL) slice supplementation improved the aforementioned physiological properties. More importantly, microbiome and metabolites analysis indicated cadmium exposure significantly reduced the generation of short-chain fatty acids in the gut, particularly butyrate. However, rats in the FGL group had the highest level of butyrate in the feces, characterized with significantly enriched probiotics (Lactobacillus, Bifidobacterium) and butyrate-producing bacteria (Roseburia). CONCLUSION: The targeted regulation of the gut microbial community and its metabolites might be the essential association for attenuating body dysfunction induced by cadmium. The supplementation of FGL, as evidenced in this study, might highlight a novel approach to this field. © 2022 Society of Chemical Industry.

Chitosan-functionalized lipid-polymer hybrid nanoparticles for oral delivery of silymarin and enhanced lipid-lowering effect in NAFLD.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a chronic disease that causes excessive hepatic lipid accumulation. Reducing hepatic lipid deposition is a key issue in treatment and inhibition of NAFLD evolution. Silymarin is a potent hepatoprotective agent; however, it has low oral bioavailability due to its poor aqueous solubility and low membrane permeability. Unfortunately, few studies have addressed the development of convenient oral nanocarriers that can efficiently deliver silymarin to the liver and enhance its lipid-lowering effect. We designed silymarin-loaded lipid polymer hybrid nanoparticles containing chitosan (CS-LPNs) to improve silymarin bioavailability and evaluated their lipid-lowering effect in adiponutrin/patatin-like phospholipase-3 I148M transgenic mice, an NAFLD model. RESULTS: Compared to chitosan-free nanoparticles, CS-LPNs showed 1.92-fold higher uptake by fatty liver cells. Additionally, CS-LPNs significantly reduced TG levels in fatty liver cells in an in vitro lipid deposition assay, suggesting their potential lipid-lowering effects. The oral bioavailability of silymarin from CS-LPNs was 14.38-fold higher than that from suspensions in rats. Moreover, compared with chitosan-free nanoparticles, CS-LPNs effectively reduced blood lipid levels (TG), improved liver function (AST and ALT), and reduced lipid accumulation in the livers of mice in vivo. Reduced macrovesicular steatosis in pathological tissue after CS-LPN treatment indicated their protective effect against liver steatosis in NAFLD. CONCLUSIONS: CS-LPNs enhanced oral delivery of silymarin and exhibited a desirable lipid-lowering effect in a mouse model. These findings suggest that CS-LPNs may be a promising oral nanocarrier for NAFLD therapeutics.

Mucosal transfer of wheat germ agglutinin modified lipid-polymer hybrid nanoparticles for oral delivery of oridonin.

Wheat germ agglutinin-modified lipid-polymer hybrid nanoparticles (WGA-LPNs) promote cellular uptake after oral delivery via receptor-mediated endocytosis and bioadhesion. Understanding the mucosal transport of WGA-LPNs would help to improve bioavailability and ensure therapeutic efficacy. In this study, WGA-LPNs interacted with mucin, forming larger agglomerates with intact core-shell structure. The interaction of WGA-LPNs with mucin improved enterocyte endocytosis in Caco-2 cells. An in situ intestinal diffusion study in mice confirmed that WGA-LPNs reached enterocytes and underwent endocytosis, despite interference from mucin. Importantly, oral bioavailability of oridonin-loaded WGA-LPNs increased by 1.96-fold compared with that of LPNs. Furthermore, oral administration of WGA-LPNs inhibited tumor growth in HepG2 xenograft nude mice. In addition to elucidating interactions between WGA-LPNs and mucin, these results indicated that WGA-LPNs might act as promising nanocarriers for oral delivery of drugs.

Global burden of cardiovascular diseases attributed to low physical activity: An analysis of 204 countries and territories between 1990 and 2019.

Background: Low physical activity is a major risk factor for cardiovascular diseases (CVDs). This study aimed to estimate the global, regional, national, and sex-age-specific burden of CVDs attributed to low physical activity from 1990 to 2019. Methods: We leveraged data from the Global Burden of Disease Study 2019 to compute the number of fatalities, disability-adjusted life years (DALYs), age-adjusted mortality rates (ASMR), and age-adjusted DALY rates (ASDR) attributed to CVDs resulting from low physical activity. Furthermore, we scrutinized the trends and correlations of these metrics in connection with the socio-demographic index (SDI) across 21 regions and 204 countries and territories. Results: The global deaths and DALYs due to CVDs caused by low physical activity increased from 371,042.96 [95 % UI: 147,621.82-740,490] and 6,282,524.95 [95 % UI: 2,334,970.61-13,255,090.08] in 1990 to 639,174.92 [95 % UI: 272,011.34-1,216,528.4] and 9,996,080.17 [95 % UI: 4,130,111.16-20,323,339.89] in 2019, respectively. The corresponding ASMR and ASDR decreased from 12.55 [95 % UI: 5.12-24.23] and 181.64 [95 % UI: 71.59-374.01] in 1990 to 8.6 [95 % UI: 3.68-16.28] and 127.52 [95 % UI: 53.07-256.55] in 2019, respectively. Deaths and DALYs attributed to low physical activity were initially higher in males but shifted to females after 70-74 age group. Both genders had increasing death rates, peaking at 80-84 age group. Most CVDs deaths and DALYs number are caused by ischemic heart disease. The highest burden of CVDs attributed to low physical activity was observed in North Africa and the Middle East. The lowest burden was observed in Oceania and High-income Asia Pacific. There was a distinctive 'n-shape' relationship between the regional SDI and the ASDR of CVDs attributed to low physical activity from 1990 to 2019. Conclusion: The global impact of CVDs stemming from low physical activity remains substantial and demonstrates substantial regional disparities. As individuals age, this burden becomes more prominent, particularly among females. Efficacious interventions are imperative to promote physical activity and mitigate the risk of CVDs across diverse populations and regions.

17ß-Estradiol promotes metastasis in triple-negative breast cancer through the Calpain/YAP/ß-catenin signaling axis.

ß-catenin is an important regulator of malignant progression. 17ß-Estradiol (E2), an important sex hormone in women, promotes the growth and metastasis of triple-negative breast cancer (TNBC). However, whether ß-catenin is involved in E2-induced metastasis of TNBC remains unknown. In this study, we show that E2 induces the proliferation, migration, invasion, and metastasis of TNBC cells. E2 induces ß-catenin protein expression and nuclear translocation, thereby regulating the expression of target genes such as Cyclin D1 and MMP-9. The inhibition of ß-catenin reversed the E2-induced cell malignant behaviors. Additionally, E2 activated Calpain by increasing intracellular Ca2+ levels and reducing calpastatin levels. When Calpain was inhibited, E2 did not induce the proliferation, migration, invasion, or metastasis of TNBC cells. In addition, E2 promoted translocation of YAP into the nucleus by inhibiting its phosphorylation. Calpain inhibition reversed the E2-induced YAP dephosphorylation. Inhibition of YAP transcriptional activity reversed the effects of E2 on the proliferation, migration, invasion, and ß-catenin of TNBC cells. In conclusion, we demonstrated that E2 induced metastasis-related behaviors in TNBC cells and this effect was mediated through the Calpain/YAP/ß-catenin signaling pathway.

Correction: Attenuation of metabolic syndrome in the ob/ob mouse model by resistant starch intervention is dose dependent.

Correction for 'Attenuation of metabolic syndrome in the ob/ob mouse model by resistant starch intervention is dose dependent' by Anqi Wang et al., Food Funct., 2019, 10, 7940-7951, https://doi.org/10.1039/C9FO01771B.

Crop rotation and native microbiome inoculation restore soil capacity to suppress a root disease.

It is widely known that some soils have strong levels of disease suppression and prevent the establishment of pathogens in the rhizosphere of plants. However, what soils are better suppressing disease, and how management can help us to boost disease suppression remain unclear. Here, we used field, greenhouse and laboratory experiments to investigate the effect of management (monocropping and rotation) on the capacity of rhizosphere microbiomes in suppressing peanut root rot disease. Compared with crop rotations, monocropping resulted in microbial assemblies that were less effective in suppressing root rot diseases. Further, the depletion of key rhizosphere taxa in monocropping, which were at a disadvantage in the competition for limited exudates resources, reduced capacity to protect plants against pathogen invasion. However, the supplementation of depleted strains restored rhizosphere resistance to pathogen. Taken together, our findings highlight the role of native soil microbes in fighting disease and supporting plant health, and indicate the potential of using microbial inocula to regenerate the natural capacity of soil to fight disease.

Physicochemical and volatile characteristics present in different grain layers of various rice cultivars.

Five rice cultivars were applied for investigating effect of milling degree on rice physicochemical properties. The first layer had the lowest peak viscosity, followed by the second and third layers, indicating the effect of non-starchy components on starch gelatinization behaviors. Consistently, more content of non-starch components in the first layer led to an enhanced gelatinization temperature. Rheological study demonstrated the G' and G" were successively increased as the layer moved inward, indicating a stronger gel network due to the increased amylose content and crystallinity in the corresponding layer. This is the first study to reveal the second layer has the highest digestibility, suggesting both non-starch components and starch structure control starch digestion. Furthermore, analysis of volatile compounds found alcohols and ketones concentrated in the first layer, whilst compounds including (E,E)-2,4-decadienal, 3-octanone and 3-nonen-2-one only existed in the second layer, serving as an indicator for managing the rice quality during milling.

Anxiety, home blood pressure monitoring, and cardiovascular events among older hypertension patients during the COVID-19 pandemic.

The global coronavirus disease 2019 (COVID-19) pandemic has led to a health crisis. It remains unclear how anxiety affects blood pressure (BP) and cardiovascular risk among older patients with hypertension. In this study, we extracted longitudinal data on home BP monitored via a smartphone-based application in 3724 elderly patients with hypertension from a clinical trial (60-80 years; 240 in Wuhan and 3484 in non-Wuhan areas) to examine changes in morning BP during the COVID-19 outbreak in China. Anxiety was evaluated using Generalized Anxiety Disorder-7 item scores. Changes in morning systolic BP (SBP) were analyzed for five 30-day periods during the pandemic (October 21, 2019 to March 21, 2020), including the pre-epidemic, incubation, developing, outbreak, and plateau periods. Data on cardiovascular events were prospectively collected for one year. A total of 262 individuals (7.0%) reported an increased level of anxiety, and 3462 individuals (93.0%) did not. Patients with anxiety showed higher morning SBP than patients without anxiety, and the between-group differences in SBP change were +1.2 mmHg and +1.7 mmHg during the outbreak and plateau periods (P < 0.05), respectively. The seasonal BP variation in winter among patients with anxiety was suppressed during the pandemic. Anxious patients had higher rates of uncontrolled BP. During the 1-year follow-up period, patients with anxiety had an increased risk of cardiovascular events with a hazard ratio of 2.47 (95% confidence interval, 1.10-5.58; P = 0.03). In summary, COVID-19-related anxiety was associated with a short-term increase in morning SBP among older patients and led to a greater risk of cardiovascular events. (ClinicalTrials. gov number, NCT03015311).

Efficacy and safety of sacubitril-valsartan in patients with heart failure: a systematic review and meta-analysis of randomized clinical trials: A PRISMA-compliant article.

BACKGROUND: To investigate the efficacy and safety of sacubitril-valsartan in patients with heart failure, relevant randomized clinical trials (RCTs) were analyzed. METHODS: We used Cochrane Library, PubMed web of science, CNKI, VIP, Medline, ISI Web of Science, CBMdisc, and Wanfang database to conduct a systematic literature research. A fixed-effects model was used to evaluate the standardized mean differences (SMDs) with 95% confidence intervals. We conducted sensitivity analysis and analyzed publication bias to comprehensively estimate the efficacy and safety of sacubitril-valsartan in patients with heart failure. RESULTS: Among 132 retrieved studies, 5 relevant RCTs were included in the meta-analysis. The result showed that left ventricular ejection fraction (LVEF) was improved after sacubitril-valsartan in patients with heart failure, with an SMD (95% CI of 1.1 [1.01, 1.19] and P < .00001 fixed-effects model). Combined outcome indicators showed that, combined outcome indicators showed that, compared with control group, the left ventricular volume index (LAVI) (WMD = -2.18, 95% CI [-3.63, -0.74], P = .003), the E/e' (WMD = -1.01, 95% CI [-1.89, -0.12], P = .03), the cardiovascular death (RR = 0.89, 95% CI [0.83, 0.96], P = .003], and the rehospitalization rate of heart failure (RR = 0.83, 95% CI [0.78, 0.88], P < .01) decreased more significantly, but it had no effect on renal function (WMD = 0.74, 95% CI [0.54, 1.01], P = .06). CONCLUSIONS: The present meta-analysis suggested that sacubitril-valsartan may improve the cardiac function of heart failure. Given the limited number of included studies, additional large sample-size RCTs are required to determine the long-term effect of cardiac function of sacubitril-valsartan in patients with heart failure.

Characterizing the volatile compounds of different sorghum cultivars by both GC-MS and HS-GC-IMS.

The current study applied both GC-MS and GC-IMS for characterizing the volatile compounds of six Australian sorghum cultivars. For raw sorghum, the result of GC-MS showed that the ester compounds were abundant in six raw samples. Among these esters, the content of hexadecanoic acid ethyl ester was highest in all of the raw samples. Compound 3-octanone only existed in Apollo, Bazley and Liberty, and 2-undecanone was found to be in MR43. The result of GC-IMS showed that the signals of benzaldehyde, 2,3-butanedione were generally noted in the six raw samples. In general, The Apollo and Buster had more volatile compounds, followed by Bazley and Liberty. In contrast, MR43 and G44 had the least volatile compounds. For cooked sorghums, more fatty aldehydes are formed compared to its corresponding raw sample, in which the current data indicated that 40 volatile compounds were identified by GC-MS, and 11 of them were identified as the key aroma compounds (OAVs > 1). More important, the variation in the compounds of hexanal, heptanal, octanal, 2-heptenal, nonanal, trans- 2-octenal, benzeneaceldehyde, (E)-2-nonenal, 1-octen-3-ol, 1-pentanol, 2-methoxy-4-vinylphenol and 2-pentylfuran might be applied for explaining the aroma characteristics among the six sorghum cultivars. The result of GC-IMS showed that 26 volatile compounds but not in the results from GC-MS detection, indicating the advantage of the methodology combination for a better understanding the impact of cultivars and cooking on volatile characteristics of the sorghums.

Functional analysis of ceRNA network of lncRNA TSIX/miR-34a-5p/RBP2 in acute myocardial infarction based on GEO database.

The identification of innovative gene biomarkers with clinical efficacy is warranted for the treatment of acute myocardial infarction (AMI). The current study sought to screen potential target genes in AMI via bioinformatic analysis and analyze their effects on cardiomyocyte apoptosis. The differentially expressed long non-coding RNAs (lncRNAs) of AMI were screened, and the downstream microRNAs (miRNAs) and mRNAs of lncRNA antisense for X-inactive-specific transcript (lncRNA TSIX) were predicted accordingly. The diagnostic relationship between the 12 differentially expressed lncRNAs and AMI was analyzed by receiver operating characteristic (ROC). Next, the expressions of 12 lncRNAs, including miR-34a-5p and retinol binding protein 2 (RBP2) were all detected. The targeting relationships of miR-34a-5p with lncRNA TSIX and RBP2 were verified. AMI model was established and treated with Ad-TSIX and/or agomiR-34a-5p to evaluate the cardiac function and cardiomyocyte apoptosis of AMI mice. LncRNA TSIX was identified as the most differentially expressed lncRNA in AMI. Our findings revealed that LncRNA TSIX could function as an AMI diagnostic marker. LncRNA TSIX could target miR-34a-5p and miR-34a-5p could target RBP2. Upregulation of lncRNA TSIX could ameliorate cardiac injury inflicted by AMI and mitigate cardiomyocyte apoptosis. Upregulation of miR-34a-5p reversed the effect of lncRNA TSIX overexpression to ameliorate cardiomyocyte apoptosis in AMI mice. Overall, the overexpression of lncRNA TSIX inhibits cardiomyocyte apoptosis by competing with RBP2 to bind to miR-34a-5p and promoting RBP2.

Analysis of secondary metabolites induced by yellowing process for understanding rice yellowing mechanism.

The current study applied wide-targeted metabolomics based approach using LC-ESI-MS/MS to characterize the secondary metabolic difference between yellowed and normal rice. The results indicated that the biosynthesis of secondary metabolites including flavonoids, flavonols and phenolic acids was significantly enhanced during the rice yellowing process, which appears to be highly managed by phenylpropanoid metabolism and flavonoid biosynthetic pathways. Furthermore, rice yellowing led to an increased color parameter b* value, and a number of increased secondary metabolites in the yellowed rice such as homoeriodictyol, naringenin chalcone, 4,2',4',6'-tetrahydroxychalcone contributed to the yellow color. These may have application as potential biomarkers for characterizing rice yellowing.

Ultrasonication enhanced the multi-scale structural characteristics of rice starch following short-chain fatty acids acylation.

Considering the variation of the diffusion character of the three anhydrides, ultrasonication was applied for investigating its impact on the reaction efficiency of the rice starch acylation from three short-chain fatty acids (SCFAs). The current data indicated that the signal peak of the FTIR spectrum at 1720 cm-1 and additional resonances in the NMR confirmed the occurrence of the acylation reaction onto the starch molecules. More interestingly, this is the first study to reveal that a lower power density ultrasonication improved the reaction efficiencies of acetylation (19%), while a higher power density could lead to a reduced acylation reactivity of propionylation compared to the control one. On the contrary, the reaction efficiency of butyrylation (64%) was significantly enhanced by the ultrasound-assisted treatment with a greater association between reaction efficiency and ultrasonic power density, indicating the importance of the diffusion character for impacting the acylation reactivity among these three anhydrides. The ultrasonic-assisted SCFAs-modified rice starch has a lower peak viscosity and setback value, indicating that the replacement of the acyl groups for OH groups in the starch avoids starch molecules rearrangement. Meanwhile, the rheological properties exhibited that the starch achieved from ultrasonic-assistance significantly reduced the area of the hysteresis curve, suggesting a destroyed gel textural property. Thus, an appropriate ultrasonication but not all could effectively enhance the acylation efficiency and improve starch rheological property.

Convenient Heme Nanorod Modified Electrode for Quercetin Sensing by Two Common Electrochemical Methods.

Quercetin (Qu) is one of the most abundant flavonoids in the human diet. High concentrations of Qu can easily cause adverse effects and induce inflammation, joint pain and stiffness. In this study, Heme was used as a sensitive element and deposited and formed nanorods on a glassy carbon electrode (GCE) for the detection of Qu. The Heme/GCE sensor was characterized using scanning electron microscopy (SEM), cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques. Under optimized conditions, the developed sensor presented a linear concentration ranging from 0.1 to 700 µmol·L-1 according to the CV and DPV methods. The detection limit for the sensor was 0.134 µmol·L-1 and its sensitivity was 0.12 µA·µM-1·cm-2, which were obtained from CV analysis. Through DPV analysis we obtained a detection limit of 0.063 µmol·L-1 and a sensitivity of 0.09 µA·µM-1·cm-2. Finally, this sensor was used to detect the Qu concentration in loquat leaf powder extract, with recovery between 98.55-102.89% and total R.S.D. lower than 3.70%. The constructed electrochemical sensor showed good anti-interference, repeatability and stability, indicating that it is also usable for the rapid detection of Qu in actual samples.

Association of enriched metabolites profile with the corresponding volatile characteristics induced by rice yellowing process.

Change in metabolites and volatiles during yellowing process in six rice cultivars was analyzed. Based on the yellowness, the study indicated Japonica was more prone to yellowing than Indica rice. Metabonomics analysis showed most differential metabolites were up-regulated, in which pathways of flavone and flavonol biosynthesis were significantly enriched following the yellowing process. Meanwhile, 54 differential metabolites were overlapped in six comparative groups, which is characterized by commonly-shared metabolic regulation pathway in each rice. Phenylalanine content was increased, followed by the enhanced phenylpropanoids formation, showing transformation between primary and secondary metabolites during yellowing process. Furthermore, 43 volatile compounds were identified, and the yellowed rice had more volatiles, including ketones, alcohols, esters and hydrocarbons, suggesting a positive correlation with the yellowing. Compounds 6-methyl-5-hepten-2-one and 6,10,14-trimethyl-2-pentadecanone were increased steadily during yellowing process, which may be applied for monitoring rice yellowing progress. This investigation provides further insight for revealing rice yellowing mechanism.

Comparative non-targeted metabolomic analysis reveals insights into the mechanism of rice yellowing.

Yellowing of rice during storage is a highly concerned issue for managing rice quality whereas the yellowing mechanism is not clearly elucidated so far. Thus, the comparative untargeted metabolomic analysis was performed in this study. The results revealed that glycolysis pathway and tricarboxylic acid cycle (TCA) were significantly enhanced in yellowed rice, indicating the activated energy metabolism was trigged during the yellowing process. In addition, the increased aromatic compounds (4-hydroxycinnamic acid and benzoic acid) and their precursors (phenylalanine, tyrosine) suggested the activation of shikimate-phenylpropanoid biosynthesis in yellowed rice, which is an antioxidant defense related pathway. In particular, the pathways involved in the metabolism of glutamate and arginine also significantly altered in yellowed rice. Therefore, the enriched pathways of increased amino acids, sugars, sugar alcohols, and intermediates of the TCA cycle during yellowing process are proposed to be associated with the response of heat and dry induced by the yellowing process.

Analysis of the physiochemical properties of rice induced by postharvest yellowing during storage.

Pasting properties indicated that the yellowing process led to a reduced peak viscosity and breakdown value of the postharvest yellowing (PHY) rice compared to corresponding normal one. More importantly, the current study revealed that both moduli of G' and G″ of the gel formed from the PHY rice was lower than that of its corresponding rice and the yellowing significantly reduced the area of the hysteresis curve. Thus, it is proposed that PHY may inhibit the formation of a continuous network structure. Studies of moisture absorption dynamics and low-field NMR suggested that the yellowing process led to a faster moisture absorption and de-absorption, indicating a faster moisture fluidity in rice kernels induced by yellowing process. Potent of the "capillary channels" might be formed during rice yellowing, and these structural characteristics may be associated with its higher digestibility due to the accelerated diffusion of the digestive enzymes in rice kernels.