Lipid concomitant γ-oryzanol decreased oil absorbency of French fries by changing the microstructure of French fries and physical properties of frying oil.

BACKGROUND: The aim of this research was to evaluate the possibility of lipid concomitant γ-oryzanol reducing oil absorbency of fried foods and the underlying mechanism. Therefore, the influence of γ-oryzanol on moisture and oil content, and distribution and micromorphology of French fries and the viscosity, fatty acid composition and total polar compounds content of rice bran oil (RBO) after frying were studied. RESULTS: Our results showed that the incorporation of low concentration of γ-oryzanol [low addition group (LAG)] (5.754 g/kg) decreased the oil absorbency and porous structure of French fries during frying. Additionally, LAG incorporation inhibited the degradation of linoleic acid, decreased the growth rate of saturated fatty acids, total polar compounds and viscosity of frying oil. CONCLUSIONS: Consequently, it was recommended to incorporate a small amount of γ-oryzanol in frying oil because it could inhibit oil absorption behavior of French fries. © 2023 Society of Chemical Industry.

Inhibitory effect of resveratrol on swimming motility and adhesion ability against Salmonella enterica serovar Typhimurium infection.

Salmonella enterica serovar Typhimurium (S. typhimurium) is a common Gram-negative foodborne pathogen that threatens public health and hinders the development of livestock industry. Resveratrol, an important component in grape fruits and seeds, has been shown to possess multiple biological activities, but its potential effects on S. typhimurium-mediated virulence have been rarely reported. In this study, we investigated the effect of resveratrol on S. typhimurium flagella -mediated virulence. The results showed that resveratrol significantly reduced the transcription of flagella genes and swimming motility of S. typhimurium, and also inhibited the transcription of T3SS-related virulence genes with varying degrees inhibiting bacterial growth. Simultaneously, resveratrol significantly reduced the adhesion of S. typhimurium to HeLa cells. Unfortunately, resveratrol does not improve the survival rate of S. typhimurium-infected mice, but it reduces the bacterial load in the liver and spleen of infected mice, and it also has a certain degree of anti-inflammatory activity. In summary, these results indicated that resveratrol has the potential to be developed as an alternative drug or antibacterial agent to prevent Salmonella infection.

Carotenogenesis and chromoplast development during ripening of yellow, orange and red colored Physalis fruit.

MAIN CONCLUSION: Formation of specific ultrastructural chromoplastidal elements during ripening of fruits of three different colored Physalis spp. is closely related to their distinct carotenoid profiles. The accumulation of color-determining carotenoids within the chromoplasts of ripening yellow, orange, and red fruit of Physalis pubescens L., Physalis peruviana L., and Physalis alkekengi L., respectively, was monitored by high-performance liquid chromatography/diode array detector/tandem mass spectrometry (HPLC-DAD-MS/MS) as well as light and transmission electron microscopy. Both yellow and orange fruit gradually accumulated mainly ß-carotene and lutein esters at variable levels, explaining their different colors at full ripeness. Upon commencing ß-carotene biosynthesis, large crystals appeared in their chromoplasts, while large filaments protruding from plastoglobules were characteristic elements of chromoplasts of orange fruit. In contrast to yellow and orange fruit, fully ripe red fruit contained almost no ß-carotene, but esters of both ß-cryptoxanthin and zeaxanthin at very high levels. Tubule bundles and unusual disc-like crystallites were predominant carotenoid-bearing elements in red fruit. Our study supports the earlier hypothesis that the predominant carotenoid type might shape the ultrastructural carotenoid deposition form, which is considered important for color, stability and bioavailability of the contained carotenoids.

Atractylodin attenuates lipopolysaccharide-induced acute lung injury by inhibiting NLRP3 inflammasome and TLR4 pathways.

Acute lung injury (ALI) arises from uncontrolled pulmonary inflammation with high mortality rates. Atractylodin (Atr) is a polyethylene alkynes and has been reported to possess anti-inflammation effect. Thus, we aimed to investigate the protective effect of Atr on lipopolysaccharide (LPS)-induced inflammatory responses ALI. The results indicated that Atr treatment not only significantly attenuated LPS-stimulated histopathological changes but also lessened the myeloperoxidase (MPO) activity, the wet-to-dry weight ratio of the lungs, protein leakage and infiltration of inflammatory cells. Moreover, Atr inhibited the tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1ß and monocyte chemoattractant protein (MCP)-1 secretion in BALF. Further study demonstrated that such inhibitory effects of Atr were due to suppression of nucleotide-binding domain-(NOD-) like receptor protein 3 (NLRP3) inflammasome and toll like receptor 4 (TLR4) activation, likely contributing to its anti-inflammatory effects. Collectively, these findings suggest that Atr may be an effective candidate for alleviating LPS-induced inflammatory responses.

The analysis of educational informatization management learning model under the internet of things and artificial intelligence.

This study explores the influence of the Internet of Things (IoT) and Artificial Intelligence (AI)-enhanced learning models on student management in educational informatization management. A game-theoretic enhanced learning model is proposed to achieve this objective, incorporating resource scheduling strategies under fog computing and a student management system that integrates IoT and AI technologies. This model's performance and the student management system are then tested. The results indicate that the fog computing-based hierarchical Q-learning (Q) model proposed in this study achieves faster convergence than a single Q model, reaching convergence after 80 training rounds, ten rounds earlier than the comparative algorithm. The model exhibits a lower average workload delay of 0.5 ms and fog node delay below 1 ms, showcasing significant advantages in terms of overall cost-effectiveness, thus minimizing service costs. The student management system has 3000 concurrent user connections, static page request times ranging from 0 to 25 s, login response time predominantly at 60 s, and a capacity to process up to 20 parallel tasks per second with zero errors. The system functionalities are fully realized, meeting usage demands effectively and achieving the highest average functional score of 9.03 for online interaction functionality. This study demonstrates the efficacy of the game-theoretic enhanced learning model in a fog computing environment and the positive impact of IoT and AI technologies on student management. The proposed student management system better caters to individual student needs, enhancing learning outcomes and experiences. The study's innovation lies in the integration of IoT technology with AI-enhanced learning models, coupled with the introduction of game-theoretic resource scheduling strategies, enabling the student management system to intelligently identify student requirements, allocate learning resources, and dynamically optimize the educational process, ultimately improving learning outcomes. This holds significant implications for enhancing education quality and promoting personalized student development.

Effects of Kiwifruit Dietary Fibers on Pasting Properties and In Vitro Starch Digestibility of Wheat Starch.

In this study, the roles of kiwifruit soluble/insoluble dietary fiber (SDF/IDF, respectively) in the pasting characteristics and in vitro digestibility of wheat starch were explored. According to RVA and rheological tests, the IDF enhanced the wheat starch viscosity, decreased the gelatinization degree of the starch granules, and exacerbated starch retrogradation. The addition of SDF in high quantities could reduce the starch gelatinization level, lower the system viscosity, and exacerbate starch retrogradation. Through determining the leached amylose content and conducing scanning electron microscopy, the IDF and SDF added in high quantities was combined with the leached amylose wrapped around the starch granules, which reduced the leached amylose content and decreased the gelatinization degree of the starch granules. The Fourier transform infrared results showed that the addition of both the IDF and SDF resulted in an enhancement in hydrogen bonding formed by the hydroxyl groups of the system. The in vitro digestion results strongly suggested that both the IDF and SDF reduced the wheat starch digestibility. The above findings are instructive for the application of both IDF and SDF in starchy functional foods.

The interaction of peptide inhibitors and Aß protein: Binding mode analysis, inhibition of the formation of Aß aggregates, and then exert neuroprotective effects.

Introduction: The misfolding and aggregation of ß-amyloid (Aß) easily form Aß fibers, which are continuously deposited in the brain, leading to the massive generation of amyloid plaques, severely destroying neuronal connections, and promoting Alzheimer's disease (AD) The occurrence and development of AD is one of the pathogenesis of AD. There is an urgent need to develop inhibitors against Aß aggregation, which is hopefully a potential way to treat AD. Methods: In this study, we first found the crystal structure of the Aß1-42 receptor protein from the RCSB PDB protein structure database and used the SYBYL X2.0 software for molecular docking, and then used the Peptide Ranker, Innovagen, DPL, and ToxinPred online websites to perform peptides. Predict the activity score, toxicity and water solubility, and then calculate the affinity constant KD value of polypeptide and Aß through Surface Plasmon Resonance (SPR) experiment. Subsequently, the CCK-8 kit method was used to determine the toxicity of different concentrations of peptides (3.125, 6.25, 12.5, 25, 50, 100, 200 µM) to PC12 cells, and then the peptides and Aß according to different concentration ratios (1:4, 1:2, 1:1, 1:0.5, 1:0.25, 0:4), this method is also used to detect the effect of peptides on Aß-induced neurotoxicity. The thioflavin T (ThT) fluorescence method was used to detect the effects of peptides (50 µM) on Aß (25 µM) aggregation inhibitory effect. Results: The results showed that the CScore of YVRHLKYVRHLK peptide molecule docking was 10.0608, the predicted activity score was 0.20, and the KD value was 5.385 × 10-5. The ThT and CCK-8 kit method found that the peptide itself is less toxic to PC12 cells at a concentration of 50 µM, and it has a significant inhibitory effect on the formation of Aß1-42 aggregates when incubated with Aß1-42 at a ratio of 1:1 (p < 0.05) and can significantly reduce the PC12 cytotoxicity induced by Aß1-42 (p < 0.05). Conclusion: In conclusion, the polypeptide YVRHLKYVRHLK designed in this study has a neuroprotective effect on PC12 cytotoxicity induced by Aß1-42. Graphical Abstract.

The Positive Effect of 6-Gingerol on High-Fat Diet and Streptozotocin-Induced Prediabetic Mice: Potential Pathways and Underlying Mechanisms.

The purposes of the present work are to assess how 6-gingerol (6G) positively influences serum glucose regulation in mice with prediabetes triggered by streptozotocin (STZ) plus a high-fat diet (HFD) and to clarify its underlying mechanisms. An analysis of prediabetic symptoms and biochemical characteristics found that 6G intervention was significantly associated with reduced fasting glucose levels, alleviated insulin resistance, better glucose tolerance, hepatic and pancreatic impairment, and dyslipidemia. For the recognition of the target gut microbiota and the pathways linked to 6G's hypoglycemic function, a combination of hepatic RNA and 16S rRNA sequencing was employed. Specifically, 6G significantly improved the dysbiosis of the gut microbiota and elevated the relative abundances of Alistipes, Alloprevotella, and Ruminococcus_1. Furthermore, 6G supplementation inhibited gluconeogenesis and stimulated glycolysis by activating the PI3K/AKT axis, which also repressed the oxidative stress through Nrf2/Keap1-axis initiation. In addition, Spearman's correlation analyses reveal a complex interdependency set among the gut microbiota, metabolic variables, and signaling axes. Taken together, the hypoglycemic effect of 6G is partially mediated by altered gut microbiota, as well as by activated Nrf2/Keap1 and PI3K/AKT axes. Thus, 6G may be used as a candidate dietary supplement for relieving prediabetes.

Maillard induced glycation of ß-casein for enhanced stability of the self-assembly micelles against acidic and calcium environment.

Bovine ß-casein (ß-CN) has attracted increasingly interest as biocompatible nanocarrier for hydrophobic flavonoid due to its self-assembly ability to form micelles. This paper reported Maillard induced glycation reaction of ß-CN using dextran in order to improve stability of naringenin-loaded ß-CN micelles under acidic and high calcium environments. Our results showed that solubility of ß-CN-graft-dextran was remarkable increased at acidic pH and the conjugation with 20 kDa dextran had the highest level of graft degree. Glycation restrained ß-CN from aggregating around pH 5.0 where was close to the isoelectric point, forming spherical micelles with irregular and rough surfaces, which were significantly larger than the micelles at pH 7.0. ß-CN-graft-dextran also overcame destabilization of the micelles induced by excess calcium and had no impact on the chelating ability of calcium. These findings appeared to be promising for future applications of modified ß-CN-graft-dextran based on Maillard reaction as fairly stable nanocarrier under extreme condition.

Insoluble and Soluble Dietary Fibers from Kiwifruit (Actinidia deliciosa) Modify Gut Microbiota to Alleviate High-Fat Diet and Streptozotocin-Induced TYPE 2 Diabetes in Rats.

This study aims to examine the anti-diabetic properties of insoluble and soluble dietary fibers from kiwifruit (KIDF and KSDF) in rats with type 2 diabetes mellitus (T2DM) resulting from a high-fat diet (HFD) and streptozotocin (STZ). Both KIDF and KSDF treatments for four weeks remarkably decreased body weight and increased satiety. In addition, the blood glucose level and circulatory lipopolysaccharide (LPS) content were decreased, while the insulin resistance, inflammatory status, and lipid profiles improved. These anti-diabetic effects might be related to the regulation of gut microbiota and increased SCFA content. The key microbial communities of KIDF and KSDF were different. Furthermore, the KIDF treatment increased the level of total SCFAs and isobutyric acid, while KSDF increased the levels of total SCFAs and butyric acid. The association between critical species and SCFA and between SCFA and biochemical parameters indicated that the mechanisms of KIDF and KSDF on T2DM might be different.

Bentong ginger oleoresin mitigates liver injury and modulates gut microbiota in mouse with nonalcoholic fatty liver disease induced by high-fat diet.

The present study aimed to examine the protective effect of Bentong ginger oleoresin (BGO) on the occurrence of nonalcoholic fatty liver disease (NAFLD) and its underlying mechanism. In the present study, 14-week BGO treatment reduced the high-fat diet (HFD)-induced obesity. The serum total cholesterol (TC) was reduced from 4.76 ± 0.30 to 3.542 ± 0.49 mmol/L and fatty liver score decreased to the normal level (1.6 ± 0.55). BGO had antihypercholesterolemia activity, alleviated abnormal lipid metabolism, and improved liver fat accumulation. In addition, liver inflammatory cytokine tests and Western blotting analysis indicated that BGO might play an anti-inflammatory role by mediating the NF-κB signaling pathway. Moreover, BGO regulated the gut microbiota in NAFLD mice and finally mediated their benefits for the host, which might be associated with reduced abundance of Lachnospiraceae_NK4A136_group and Fournierella. BGO showed effective liver protection and regulation of gut microbiota for the HFD-induced NAFLD in obese mice. As a result, BGO may serve as an effective dietary supplement for the improvement of NAFLD-related metabolic diseases. PRACTICAL APPLICATION: This study provides a new way to improve the added value of Bentong ginger. It also provides certain experimental data on BGO as a kind of the functional food ingredient. The current work also provides new ideas for the improvement and treatment of NAFLD.

Resveratrol Attenuates High Glucose-Induced Osteoblast Dysfunction via AKT/GSK3ß/FYN-Mediated NRF2 Activation.

Osteoblast dysfunction, induced by high glucose (HG), negatively impacts bone homeostasis and contributes to the pathology of diabetic osteoporosis (DOP). One of the most widely recognized mechanisms for osteoblast dysfunction is oxidative stress. Resveratrol (RES) is a bioactive antioxidant compound to combat oxidative damage. However, its role in the protection of HG-induced osteoblast dysfunction has not been clarified. Therefore, our study aimed to explore potential regulatory mechanisms of RES for attenuating HG-induced osteoblast dysfunction. Our results showed that osteoblast dysfunction under HG condition was significantly ameliorated by RES via the activation of nuclear factor erythroid 2-related factor (NRF2) to suppress oxidative stress. Furthermore, using Nrf2-shRNA and wortmannin, we identified that activation of NRF2 via RES was regulated by the AKT/glycogen synthase kinase 3ß (GSK3ß)/FYN axis.

Design and synthesis of a long-wavelength latent fluorogenic substrate for salicylate hydroxylase: a useful fluorimetric indicator for analyte determination by dehydrogenase-coupled biosensors.

Salicylate hydroxylase (SHL) catalyzes the production of catechol (plus CO(2) and H(2)O) from salicylate, NADH, and O(2). Coimmobilization of SHL with a NAD(P)(+)-dependent dehydrogenase in front of a Clark-type oxygen electrode has been investigated in the development of a general type of dehydrogenase-based biosensors that can detect various biological analytes; however, currently, no fluorophores are available for these applications. We synthesized the first new long-wavelength latent fluorogenic substrate SHLF (3) for SHL. In the presence of NADH and under aerobic conditions, SHL catalyzes the decarboxylative hydroxylation of SHLF followed by a quinone-methide-type rearrangement reaction concomitant with the ejection of a fluorescence coumarin 2, which is spontaneous and irreversible at physiological temperatures in aqueous media. The fluorescence signal generated by this process is specific and, in the near red spectral region with an emission maximum at 595 nm, is suppressed by salicylic acid. The fluorescence response of SHLF is insensitive to various biological reactive oxygen species (ROS) and reductants. Furthermore, SHLF is a sensitive fluorimetric indicator for analyte determination in the SHL-coupled dehydrogenase assay in which NAD(+) is converted to NADH. This novel fluorescence assay detected 3-hydroxybutyrate and cholesterol in the nanomolar range and is more sensitive than the current SHL-dehydrogenase amperometric sensors, making it applicable to the construction of a fiber-optic fluorescence biosensor for clinical diagnostic uses.

The formation process of green substances in Chrysanthemum morifolium tea.

One interesting phenomenon of Chrysanthemum morifolium tea is its formation of a green or dark green color after hours of brewing, and it is important to study the compounds that form this color and whether they might be involved in health benefits. Non-targeted metabolomics could clearly distinguish between green and non-green species by sparse partial least squares discriminant analysis (sPLS-DA) and heat-mapping. We found that the pH was the primary factor in the formation of the green color. Two green precursors (GP1 and GP2) were separated and purified with preparative HPLC. FT-IR analysis and the saccharide content analysis showed that GP1 had the typical characteristics of saccharides. GP2 was identified as chlorogenic acid by ESI-Q-TOF/MS and NMR. We raised the formation process of green substances was caused by the hydrolysates of chlorogenic acid reacting with glycosides or groups attached to the saccharides, which suggests a new mechanism for color-forming reactions.

AMPK/p38/Nrf2 activation as a protective feedback to restrain oxidative stress and inflammation in microglia stimulated with sodium fluoride.

Dysregulated activation of inflammation plays an important role in the development and progression of neuronal damage, and limiting the production of reactive oxygen species (ROS) can suppress the inflammatory signals. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a redox-sensing transcription factor that drives an adaptive cellular defense in response to oxidative stress. However, the implications of Nrf2 in sodium fluoride (NaF)-stimulated microglia and the underlying mechanisms remain obscure. In this study, we demonstrated that NaF activated the Nrf2 signaling and enhanced the downstream antioxidant protein levels, including heme oxygenase-1 and quinine oxidoreductase 1. NaF induced oxidative stress, as indicated by increased ROS level and malondialdehyde content, and reduced superoxide dismutase activity. Moreover, NaF promoted the nuclear translocation of NF-κB, thus increased the production of the pro-inflammatory cytokines tumor necrosis factor-α, interleukin (IL)-6, and IL-1ß. However, these effects were relieved by overexpression of Nrf2. Meanwhile, knockdown of Nrf2 by shRNA exacerbated NaF-induced oxidative stress and inflammation in BV-2 cells and primary cultured microglia. Mechanistically, NaF-induced Nrf2 activation is AMPK/p38 dependent, as deletion of AMPK using siRNA blocked the activating effect of NaF on p38 and Nrf2. Notably, treatment of N-Acety-l-Cysteine attenuated AMPK/p38-dependent Nrf2 activation in microglia exposed to NaF. In conclusion, these data demonstrated for the first time that Nrf2 activation exerts a neuroprotective effect on NaF-stimulated redox imbalance and inflammation that is dependent on the AMPK/p38 pathway.

Amygdalin attenuates acute liver injury induced by D-galactosamine and lipopolysaccharide by regulating the NLRP3, NF-κB and Nrf2/NQO1 signalling pathways.

Acute liver injury (ALI) is a life-threatening syndrome accompanied by overwhelming inflammation. Amygdalin (AGD) has been reported to possess various biological activities, particularly anti-inflammatory activity. The current study was designed to assess the protective effects and underlying mechanisms of AGD against ALI induced by d-galactosamine (GalN) and lipopolysaccharide (LPS) in mice. The results indicated that AGD treatment effectively reduced the lethality, ameliorated the histopathological liver changes, reduced the malondialdehyde (MDA) and myeloperoxidase (MPO) levels, and decreased the alanine transaminase (ALT) and aspartate aminotransferase (AST) levels resulting from LPS/GalN challenge. Moreover, AGD significantly inhibited LPS/GalN-induced inflammatory responses in mice with ALI by reducing not only the secretion of tumour necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 but also the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Additionally, our results demonstrated that the inhibitory effect of AGD was due to the suppressed activation of nuclear factor-kappa B (NF-κB) and nucleotide-binding domain (NOD-)like receptor protein 3 (NLRP3) inflammasome activity. Furthermore, AGD treatment substantially increased nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation and enhanced NAD (P) H: quinoneoxidoreductase 1 protein expression, which was reversed by a Nrf2 inhibitor, in HepG2 cells. In summary, our investigations suggested that the ability of AGD to ameliorate LPS/GalN-induced ALI may involve the inhibition of the NLRP3 inflammasome and NF-κB signalling pathways and the upregulation of the Nrf2/NQO1 signalling pathway.

Comparison of biochemical properties of membrane-bound and soluble polyphenol oxidase from Granny Smith apple (Malus × domestica Borkh.).

Polyphenol oxidase from Granny Smith apples was purified and characterized in both its soluble form (sPPO) and its membrane-bound form (mPPO). Both forms were purified by temperature-induced phase partitioning, precipitation with ammonium sulfate, and ion exchange chromatography. The specific activity of mPPO was 19.17 times that of sPPO. The optimum pH and temperature for both forms were 7.0 and 35 °C when catechol was the substrate. The Michaelis constant and maximum reaction rate for sPPO were 34.1 mM and 500 U/mL/min, whereas those for mPPO were 53 mM and 10,000 U/mL/min, respectively. The enzymes exhibited diphenolase activity, and their affinity was highest for catechol (sPPO) and 4-methylcatechol (mPPO). Inhibitors of sPPO and mPPO included ascorbic acid, glutathione, and l-cysteine. However, ethylenediaminetetraacetic acid increased the activity of mPPO. Purified sPPO was dimeric with a molecular weight of 31 kDa, whereas mPPO was monomeric with an estimated molecular weight of 65 kDa.

Physicochemical characteristics and phytochemical profiles of yellow and red Physalis (Physalis alkekengi L. and P. pubescens L.) fruits cultivated in China.

Physicochemical characteristics and phytochemical profiles of red (Physalis alkekengi L., RP) and yellow (P. pubescens L., YP) Physalis fruits cultivated in three provinces of China were characterized. YP fruits showed significantly lower levels of total organic acids and elevated total sugars than those of RP. A total of 18 compounds was tentatively identified in hydromethanolic extracts of Physalis fruits applying HPLC-DAD-ESI-MSn and HR-ESI-MS. Cinnamoyl and hydroxycinnamoyl conjugates prevailed in both fruits. Diverse mono- and dihexosides of cinnamic, coumaric, caffeic, ferulic, and sinapic acid were found in YP, while RP merely contained feruloyl and sinapoyl hexosides. N,N´-dicaffeoylspermidine isomers were found in YP fruits, whereas N,N´-bis(dihydrocaffeoyl)spermine was exclusively detected in two of the RP samples. Additionally, two HDMF (4-hydroxy-2,5-dimethyl-3(2H)-furanone) hexosides were tentatively identified for the first time in YP. Both RP and YP fruits collected from three different provinces in China showed a significant intraspecific variability regarding their phytochemical profiles, despite their similar morphological fruit traits.

Synthesis of a new long-wavelength latent fluorimetric indicator for analytes determination in the DT-Diaphorase coupling dehydrogenase assay system.

We synthesized a new long-wavelength latent fluorogenic probe BQC (1) to monitor DTD activity. The fluorogenic chemical transformation of BQC triggered by DTD in the presence of NADH is through a series of tandem reactions, DTD-catalyzed benzoquinone reduction, trimethyl-locks cyclization and intramolecular urea formation, which are spontaneous and irreversible at physiological temperature in aqueous media. The fluorescence signal revealed by this process is specific and exhibited in the near red spectrum region with emission maxima at 595 nm, and it could be competitively inhibited by menadione. The fluorescent response of BQC is insensitive to various biological thiol reductants. Furthermore, pro-fluorophore BQC is a sensitive fluorimetric indicator for analytes determination in the oxygen-insensitive DTD-coupled dehydrogenases assay by including NAD(+) which will convert to NADH by reaction in the presence of analytes. This novel oxygen-insensitive assay demonstrates a good relationship in detecting 3-hydroxybutyrate and glucose-1-phosphate in 1-10 microM range, which presents to the applicability for the construction of fiber-optic biosensors in the future clinical diagnostic.

Optimization of ultrasound-assisted extraction of okra (Abelmoschus esculentus (L.) Moench) polysaccharides based on response surface methodology and antioxidant activity.

This study determined the optimal conditions for ultrasound-assisted extraction of a water-soluble polysaccharide, Raw Okra Polysaccharide, from the fruit of okra using response surface methodology. The optimal extraction temperature, extraction time and ultrasonic power were 59°C, 30min and 522W, respectively, giving a yield of 10.35±0.11%. ROP was further isolated, lyophilized and purified using a DEAE-Sepharose Fast Flow column and Sepharose CL-6B column, revealing three elution peaks subsequently designated ROP -1, -2, and -3, respectively. Of these, ROP-2 showed the highest yield, and was therefore selected for physicochemical analysis and evaluation of antioxidant activity. Gas chromatography, fourier transform infrared spectroscopy, and high-performance liquid chromatography were used to characterize the primary structural features and molecular weight, revealing that ROP-2 is composed of glucose, mannose, galactose, arabinose, xylose, fructose, and rhamnose (molar percentages: 28.8, 12.5, 13.1, 15.9, 9.2, 13.7, and 6.8%, respectively) and has an average molecular weight of 1.92×105Da. A superoxide radical scavenging assay and DPPH radical scavenging assay further revealed the significant in vitro antioxidant activity of ROP-2. These findings present an effective technique for extraction of the natural antioxidant ROP-2, warranting further analysis of its potential application in the food industry.