200 assays (manual) / 2000 assays (microplate) / 1960 assays (auto-analyser)
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|Content:||200 assays (manual) / 2000 assays (microplate) / 1960 assays (auto-analyser)|
Short term stability: 2-8oC,
Long term stability: See individual component labels
|Stability:||> 2 years under recommended storage conditions|
|Assay Format:||Spectrophotometer, Microplate, Auto-analyser|
|Linear Range:||0.01 to 0.08 U/mL of glucose oxidase per assay|
|Limit of Detection:||10 U/L|
|Reaction Time (min):||~ 20 min|
|Application examples:||Enzyme preparations, and other materials (e.g. biological cultures, samples, etc.).|
|Method recognition:||Novel method|
The Glucose Oxidase assay kit is a simple procedure for the rapid and reliable measurement and analysis of glucose oxidase activity in industrial enzyme preparations and bread improver mixtures.
View more of our assay kits for enzyme activities.
- Very competitive price (cost per test)
- All reagents stable for > 12 months after preparation
- Simple format
- Mega-Calc™ software tool is available from our website for hassle-free raw data processing
- Standard included
- Suitable for manual, microplate and auto-analyser formats
Effect of Rosa Roxburghii juice on starch digestibility: A focus on the binding of polyphenols to amylose and porcine pancreatic α-amylase by molecular modeling.
Zhu, J., Zhang, B., Tan, C. P., Ding, L., Shao, M., Chen, C., Fu, X. & Huang, Q. (2022). Food Hydrocolloids, 123, 106966.
Chestnut rose (Rosa Roxburghii) is an endemic fruit in China with many bioactivities. The present study investigated the effect of chestnut rose juice concentrate (CRJC) on the digestibility of normal wheat starch (NWS), with a focus on the interaction between polyphenols and amylose as well as that between polyphenols and porcine pancreatic α-amylase (PPA). NWS was mixed with CRJC and digestibility was determined using Englyst method. The composition of CRJC was analyzed by ultrahigh performance liquid chromatography-mass spectrometry. Molecular dynamics (MD) was used to study the binding between polyphenols and PPA and between polyphenols and amylose. The results showed that CRJC could significantly increase the resistant starch content. The MD results agreed with previous docking and experimental results regarding the inhibitory effects (IEs) of polyphenols (with galloyl and glycosyl group differences) against α-glucosidase. The MD results also showed that complex polyphenols with greater molecular weights or a high number of hydrogen bond donors (HBDs)/acceptors (HBAs) bind in a stronger and more lasting manner with amylose than simple polyphenols. CRJC has the potential to reduce the risk of developing type 2 diabetes and molecular simulation can be a supporting tool to study mechanisms in food system.Hide Abstract
Genipin-mediated immobilization of glucose oxidase enzyme on carbon felt for use as heterogeneous catalyst in sustainable wastewater treatment.
Kahoush, M., Behary, N., Guan, J., Cayla, A., Mutel, B. & Nierstrasz, V. (2021). Journal of Environmental Chemical Engineering, 9(4), 105633.
Enzyme immobilization is necessary process to improve the bioactivity and stability of the biocatalyst. In this study, glucose oxidase (GOx) enzyme was immobilized on plasma-treated fibrous carbon felt as a textile carrier to produce a heterogeneous catalyst. Genipin, as a naturally occurring crosslinker, that has less cytotoxicity than conventional crosslinkers, was used in the enzyme immobilization process. UV-Vis and FTIR spectra confirmed the crosslinking reaction between genipin and the primary amines of GOx enzyme, by forming blue-pigmented aggregates. GOx relative activity after crosslinking and immobilization on the carbon felt was maintained up to 40%, with stability in performance up to 6 cycles for the plasma treated carbon, while maintaining their bio-electro-activity as shown from cyclic voltammetry scans (CV). The obtained heterogeneous catalysts have been tested for use in sustainable wastewater treatment of Remazol Blue RR (RB) dyestuff by means of Bio-Fenton (BF) and enzymatic Bio-electro-Fenton (BEF) processes. The produced samples resulted in high color removal efficiency, up to 93% discoloration of (RB) for the first use in (BF) process in 3 h. Meanwhile, enzymatic (BEF) process resulted in up to 34% of COD removal, with simultaneous power density generation up to 0.16 ± 0.01 μW.cm−2 at a current density of around 10 ± 2 μA.cm−2 in 12 h. These results highlight the importance of genipin as a bio-based crosslinker for enzymes, and the potential use in both (BF) and (BEF) as sustainable approaches for wastewater treatment and as a step towards zero-energy degradation of organic matter.Hide Abstract
One-Pot electrochemical fabrication of high performance amperometric enzymatic biosensors using polypyrrole and polydopamine.
Lee, M., Kim, S., Jang, M., Park, H. S. & Lee, J. Y. (2021). Journal of Industrial and Engineering Chemistry, 97, 316-325.
We report a novel strategy to offer a high-performance biosensor platform by fabricating an electrically conductive and adhesive electrode composed of polypyrrole (PPy)/polydopamine (PDA) with enzymes (i.e., glucose oxidase (GOx) or lactate oxidase (LOx)) by one-step electrochemical coating. We focused on electrochemical glucose sensing using PDA/PPy and GOx as a model biosensor. PDA/PPy/GOx biosensor was highly sensitive (28 times higher) compared to the PPy/GOx, which appeared to result from enhanced GOx immobilization and efficient signal transduction by PDA/PPy. A selective layer of polyphenol (PPh) on the PDA/PPy/GOx successfully eliminated possible interference. Finally, the GOx biosensor displayed a good sensitivity of 22.15 μ A mM−1 cm-2, a short response time of 5-6 s, a linear range up to 5.0 mM, and a detection limit of 138 μM glucose (R2 = 0.995). Human blood serum tests accurately measured glucose concentration. PPh-layered PDA/PPy/GOx biosensor maintained exceptional stability over 90 days (93.9%). Furthermore, we fabricated a lactate biosensor (PDA/PPy/LOx) by electrochemical PDA/PPy deposition with LOx and demonstrated the significant improvement of a lactate sensing ability compared to PPy/LOx. This facile fabrication strategy involving PDA/PPy and enzymes will serve as an attractive platform for highly sensitive and stable biosensors, such as urate and bilirubin detection.Hide Abstract
Effect of pullulanase debranching and retrogradation on resistant starch yield and glycemic Index of Garri.
Ogbo, F. C. & Nwozor, N. C. (2020). Journal of Advances in Microbiology, 67-75.
Aims: This research is aimed at developing a method of processing to increase the quantity of resistant starch in garri and reduce its glycemic index using pullulanase-producing Bacillus subtilis organism. Place and Duration of Study: Department of applied microbiology and brewing, Nnnamdi Azikiwe University, Awka between January, 2018 and February, 2019. Methodology: The organism was isolated from different cassava processing sites in Anambra metropolis, Nigeria. It was then identified based on phenotypic, biochemical and molecular characteristics After which the pullulanase assay, the fermentation studies, resistant starch analysis and glycemic index was analysed. Results: Pullulanase assay result showed Bacillus subtilis as a very good pullulanase producing organism with a pullulanase quantity of. The resistant starch content was found to be higher for the samples fermented with the choice organism and retrograded at 10oC at 14.29%, than the control garri sample fermented without any organism and not retrograded at 4.73%. The glycemic index was relatively high in all the garri samples, however, the lowest glycemic index, 62% was observed in the garri sample produced with the choice organism. Conclusion: This research has been able to show that pullulanase enzyme from Bacillus subtilis is a very useful industrial raw material in production of functional foods with low glycemic index.Hide Abstract
Physicochemical and multi-scale structural alterations of pea starch induced by supercritical carbon dioxide+ ethanol extraction.
Vatansever, S., Whitney, K., Ohm, J. B., Simsek, S. & Hall, C. (2020). Food Chemistry, 344, 128699.
The objective of this study was to establish the impacts of supercritical fluid extraction (SFE) processing on the physicochemical properties of pea flour and the structure of isolated pea starch. A significant (p < 0.05) increase in protein content and reduction in several pasting and thermal parameters as measured by rapid visco-analyzer and differential scanning calorimeter were observed after SFE. Additionally, SFE increased starch digestibility as determined by an in vitro starch digestion assay. An increased amylopectin content and crystallinity along with the loss of double helix content was supported by size exclusion chromatography and FT-IR data, respectively. X-ray diffraction and scanning electron microscopy showed minimal alterations of starch, by SFE, in long-range crystalline and morphological structure of starch granules, respectively. The data demonstrated SFE influenced the physicochemical and structural characteristics of pea starch. These outcomes illustrated that SFE might be a green and novel technology for starch modification.Hide Abstract
Quality Evaluation of ‘Fufu’ Produced from Sweet Cassava (Manihot Esculenta) and Guinea Corn (Sorghum Bicolor) Flour.
Awolu, O., Iwambe, V., Oluwajuyitan, T., Bukola Adeloye, J. & Ifesan, B. (2020). Journal of Culinary Science & Technology, 1-31
Sweet cassava and guinea corn were processed into flour using two different drying methods (sun and oven) to produce unfermented enriched fufu. Experimental design from which ten blends were selected for analyzes, sample F (100% traditional processed fufu) and sample C (commercial market sample - semolina) were used as control. In-vitro starch digestibility, glycemic index/load, antioxidant potential, and sensory attributes were evaluated, analyzed and mean were separated using Duncan New Multiple Range (DNMR) test at p ≤ 0.05. In-vitro starch digestibility of the experimental samples were significantly (p ≤ 0.05) higher than 8.91% obtained for sample F in both sun- and oven-dried samples. Results of the estimated glycemic index/load of the experimental samples showed that enriched fufu can be classified as low glycemic foods and are significantly (p ≤ 0.05) higher than sample F (55%) and glucose (100%). The samples also had better ability to scavenge free radicals against DPPH and ABTS.Hide Abstract
Effect of different cooking methods and heating solutions on nutritionally‐important starch fractions and flatus oligosaccharides in selected pulses.
Liu, Y., Ragaee, S., Marcone, M. F. & Abdel‐Aal, E. S. M. (2020). Cereal Chemistry, 97(6), 1216-1226.
Background and objectives: Consumption of pulses is recommended by health organizations. Pulses are usually soaked and cooked in water before consumption which alters their nutrient composition and ultimately health benefits. This study investigated the effect of four cooking methods (boiling, pressure, microwave, and slow) and four heating solutions (water, salt, sugar, and citric acid) on composition of nutritionally‐important starch fractions and flatus oligosaccharides in faba bean, lentil, and pea. Findings: The three pulses had slowly digestible starch (SDS) as the highest fraction with faba bean and lentil exhibited higher SDS than pea, but pea contained the highest level of resistant starch (RS). Rapidly digestible starch (RDS) was comparable among the three pulses. Stachyose and verbascose were the dominant oligosaccharides in faba bean, lentil, and pea. Regardless of the heating solution, slow cooking was more effective in improving starch nutritional fractions, i.e., producing lowest RDS and highest SDS in the three pulses with some exceptions. The RS fraction increased in the three pulses subject to cooking method and pulse type. Pressure and slow cooking methods were effective in reducing oligosaccharides in the three pulses. Conclusions: The results suggest that slow cooking in water or salt solution has great potential to improve starch nutritional fractions and diminish flatus oligo‐sugars. Significance and novelty: This is the first study to demonstrate the effectiveness of slow cooking in enhancing starch nutritional fractions and reducing flatus oligo‐sugars in pulses. The method could hold a promise for implementation especially small‐ and large‐volume slow cookers are commercially available.Hide Abstract
Changes in physicochemical, nutritional characteristics and ATR-FTIR molecular interactions of cereal grains during germination.
Kaur, H. & Gill, B. S. (2020). Journal of Food Science and Technology, 1-12.
The cereal grains such as wheat, barley, sorghum, millets were evaluated before and after germination (24 h, 48 h and 72 h) and compared for their proximate composition, antioxidant activity, total phenolic content, total flavonoid content, pasting properties, in vitro starch digestibility and FTIR spectroscopy. Germination inversely affected the protein, fat, and ash content of different cereal grains. The germinated flours have less water content and higher oil absorption capacities along with reduced starch content. The contents of rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) in the ungerminated cereal flours ranged from 20.7 to 32.1%, 26.9 to 38.0% and 6.2 to 17.6% respectively but after germination of 72 h, the RDS content increased from 26.5 to 36.2% while SDS and RS content decreased from 26.1% (sorghum) to 16% (barley) and 14.7% (barley) to 4.6% (wheat) respectively. The drought–tolerant crops (sorghum, millets and barley) are potential sources of antioxidants and phenolic content and yielded lower hydrolysis index and estimated glycaemic index upon germination. The highest section of antiparallal β-sheet, α-helix and β-turns were found in wheat flour followed by sorghum flour and their proportion decreased with continuous germination. The continuous reduction of viscosity was evaluated with the progress in germination. Overall, germination is a way to get health-promoting compounds from less utilizing cereal such as millets, sorghum and barley and enhance their uses to nourish the huge population with the aim to fulfill their nutritional requirements.Hide Abstract
Influence of resistant starch, xanthan gum, inulin and defatted rice bran on the physicochemical, functional and sensory properties of low glycemic gluten-free noodles.
Raungrusmee, S., Shrestha, S., Sadiq, M. B. & Anal, A. K. (2020). LWT, 126, 109279.
The study aims to evaluate the effects of xanthan gum (XG), inulin and defatted rice bran on the physicochemical, functional and sensory properties of the gluten-free noodle prepared from Pathumthani 80 rice (RD 31) native autoclaved resistant starch (NARS). The increase in concentration of XG (0.625-5%) in the formulation of gluten free noodles resulted a significant decrease (p ˂ 0.05) in resistant starch content whereas, the tensile strength was increased. RD 31-NARS gluten-free noodles with 2.5% XG received the high sensory scores and further selected for the addition of inulin and defatted rice bran (5%, w/w), separately. RD 31-NARS gluten free noodle with XG (2.5%) and defatted rice bran exhibited the highest protein (4.62%), fiber (0.35%) and ash content (1.45%). Further, addition of inulin and defatted rice bran significantly (p ˂ 0.05) decreased the glycemic index and increased the cooking time and firmness. The surface morphology of gluten free noodles showed relatively porous structure under the scanning electron microscope (SEM) after the addition of rice bran (5%) and inulin (5%). Thus, resistant starch along with gums and fibers can be used to develop gluten free functional foods with better acceptability.Hide Abstract
Low serum interleukin-6 is a differential marker of obesity-related metabolic dysfunction in women and men.
Méndez-García, L. A., Cid-Soto, M., Aguayo-Guerrero, J. A., Carrero-Aguirre, M., Trejo-Millán, F., Islas-Andrade, S., Fragoso, J. M., Olivos-Garcia, A. & Escobedo, G. (2020). Journal of Interferon & Cytokine Research, 40(3), 131-138.
There is scant information regarding the role of interleukin (IL)-6 in obesity-related metabolic dysfunction in humans. Thus, we studied the serum levels of IL-6 in normal weight, overweight, and obese subjects, and examined associations of IL-6 with hyperglycemia, insulin resistance, dyslipidemia, and systemic inflammation. One hundred three women and men were included in the study. Anthropometric parameters, blood glucose, insulin, total cholesterol, and triglycerides were measured. Serum levels of tumor necrosis factor-alpha (TNF-alpha), IL-10, and IL-6 were measured by enzyme-linked immunosorbent assay (ELISA). One-way analysis of variance (ANOVA) showed a 2.5-fold significant decrease in serum IL-6 in overweight and obese individuals when compared with normal weight controls. Serum IL-6 exhibited significant inverse correlations with body mass index (r = −0.39/P < 0.0001), waist circumference (r = −0.42/P < 0.001), blood glucose (r = −0.40/P < 0.0001), triglycerides (r = −0.34/P < 0.0001), and TNF-alpha (r = −0.48/P < 0.0001), whereas a strongly positive correlation was found with IL-10 (r = 0.77/P < 0.0001). Multiple linear regression analysis revealed that behavior of IL-6 was mainly influenced by IL-10 (beta = 0.28/P = 1.95 × 10−6), TNF-alpha (beta = −0.67/P = 0.0017), and body fat percentage (beta = −5.95/P = 7.67 × 10−5) in women. In contrast, IL-10 (beta = 0.37/P = 1.34 × 10−9), TNF-alpha (beta = −0.85/P = 0.0005), and triglycerides (beta = 1.07/P = 0.0007) were major influencing factors of IL-6 in men. This study demonstrates that IL-6 is a marker of metabolic dysfunction that is differentially regulated in obese women and men.Hide Abstract
Digestibility of branched and linear α-gluco-oligosaccharides in vitro and in ileal-cannulated pigs.
Hu, Y., Heyer, C. M., Wang, W., Zijlstra, R. T. & Gänzle, M. G. (2020). Food Research International, 127, 108726.
Isomalto-oligosaccharides (IMOs) may promote health by modulating intestinal microbiota. We hypothesized that the proportion of α–(1 → 6) linkages in IMOs determines their digestibility. Ileal-cannulated pigs were fed diets containing IMO, IMO-DP3 with a greater DP and more α-(1 → 4) linkages, and digestible or resistant maltodextrins. Oligosaccharides were analysed by high-performance anion-exchange chromatography. Compared to IMO, IMO-DP3 contained more panose (18.6 vs. 10.3%) but less isomaltose (7.5 vs. 22.3%) and isomaltotriose (6.1 vs. 12.6%). The apparent ileal digestibility of dry matter were 3% greater for IMO-DP3 and digestible maltodextrin than resistant maltodextrin; the digestibility of IMO was not different from other oligosaccharides. Ileal propionate, isovalerate, and total SCFA was greater for IMO-DP3 and digestible maltodextrin than IMO. In conclusion, IMO was less digestible than IMO-DP3. Structural properties of IMOs are important determinants of their functional properties within the porcine digestive tract.Hide Abstract
Impact of annealing on the hierarchical structure and physicochemical properties of waxy starches of different botanical origins.
Samarakoon, E. R. J., Waduge, R., Liu, Q., Shahidi, F. & Banoub, J. H. (2020). Food Chemistry, 303, 125344.
The effect of annealing on structure and physicochemical properties of four different waxy starches were investigated to understand the mechanism of annealing in the absence of amylose. Granule morphology, X-ray pattern, molecular order, and gelatinization enthalpy remained unchanged upon annealing. Relative crystallinity of waxy corn starch increased from 42.4 to 46.1% on annealing, while it remained unchanged in other starches. Annealing increased the gelatinization temperatures, while it decreased the temperature range. Waxy potato starch showed the highest increase in To, where it was 8.1°C after 72 h of annealing. Viscosity profiles were only slightly affected by the annealing treatment. Susceptibility towards amylolysis increased in waxy corn and waxy barley, while it decreased in waxy potato and waxy rice. This study demonstrated that even in the absence of amylose, annealing caused changes in the structure and properties, however, the extents of these changes varied depending on the botanical origin.Hide Abstract
Influence of remote plasma on PEDOT: PSS‐coated carbon felt for improved activity of glucose oxidase.
Kahoush, M., Behary, N., Cayla, A., Mutel, B., Guan, J. & Nierstrasz, V. (2020). Journal of Applied Polymer Science, 137(14), 48521.
Increasing wettability of carbon felts is an important strategy to improve their efficiency in bio‐electrochemical applications. Herein, influence of cold remote plasma (N2 + O2) treatment on surface properties of carbon felts with poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) coating was tested, aiming to improve immobilizing of glucose oxidase enzyme (GOx). Spectra of N 1s and O 1s confirmed the integration of carbonyl and ether as well as amide and amine groups on bare carbon fiber surface, while on coated fibers, carbonyl groups were pre‐dominant. S 2p spectra confirmed oxidation of PEDOT:PSS coating with reduction of (S−) compared to (SO3−) group. GOx immobilized on different samples showed highest activity for PEDOT:PSS coating subjected to plasma with 2% O2, maintaining up to 60% after immobilization, and 37% of its activity after six cycles for some samples. Enzymes immobilized on samples without plasma treatment lost their activity after four cycles.Hide Abstract
Nutritional quality of raw and cooked flours of a high β-glucan sorghum inbred line.
Hamad, S. A., Mustafa, A. I., Magboul, B. I., Qasem, A. A. & Ahmed, I. A. M. (2019). Journal of Cereal Science, 90, 102857.
This study investigated the protein fractions, in vitro protein digestibility (IVPD), in vitro starch digestibility (IVSD), antinutritional factors, hydrolysis index (HI), and estimated glycemic index (eGI) of the raw and cooked flours of a new sorghum inbred line (high β-glucan type I non-tannin sorghum) compared to two popular Sudanese sorghum cultivars (low β-glucan type 1 non-tannin and type II tannin sorghums). Significant differences (P < 0.05) were observed in protein fractions, antinutritional factors, IVPD, IVSD, rapidly digestible starch (RDS), resistant starch (RS), HI, and eGI. Low β-glucan type II tannin sorghum showed the highest antinutritional factors and RS values, whereas high β-glucan type I non-tannin and low β-glucan type 1 non-tannin sorghum cultivars showed the least values (P < 0.05). Low β-glucan type 1 non-tannin sorghum had the highest IVPD, RDS, HI, and eGI values. Cooking significantly (P < 0.05) reduced the protein fractions, antinutritional factors, IVPD, and RS and increased the IVSD, RDS, HI, and eGI of sorghums. Based on low eGI of high β-glucan type I non-tannin sorghum cultivar, it can be considered a low glycemic index sorghum and could thus be the best choice for diabetic people.Hide Abstract
Understanding the structural and digestion changes of starch in heat-moisture treated polished rice grains with varying amylose content.
Yang, X., Chi, C., Liu, X., Zhang, Y., Zhang, H. & Wang, H. (2019). International Journal of Biological Macromolecules, 139, 785-792.
Although the effects of heat-moisture treatment on starch structures and digestibility have been evaluated, the changes in structures and digestion of starches in heat-moisture treated starch-based food systems with varying amylose contents are not well understood. In the present study, starches isolated from heat-moisture treated polished rice grains were characterized with multi-scale structures and digestibility to reveal the effect of amylose in rice grains on structures and digestibility of starch subjected to heat-moisture treatment. Results indicated that heat-moisture treatment contributed to the partial gelatinization of starch granules, but also significantly reinforced the molecular interactions between starch molecules and thus increased starch resistance to hydrothermal treatment and enzymes attack. The higher amylose content of the native starch was, the greater reduction in digestion was observed for heat-moisture treated starch. Pearson's correlation matrix showed that the amylose content highly correlated with the changes in structural features (e.g., molar mass, short-range ordered structure, crystalline structure, and lamellar structure) of starches followed by heat-moisture treatment. The amylose promoted the reinforcement of interactions between starch chains during heat-moisture treatment and then significantly contributed to the reduction in starch digestibility.Hide Abstract
The role of hydrogen peroxide in the antibacterial activity of different floral honeys.
Farkasovska, J., Bugarova, V., Godocikova, J., Majtan, V. & Majtan, J. (2019). European Food Research and Technology, 245(12), 2739-2744.
Because of its powerful therapeutic potential in wound care, honey has been given much attention. One of the most relevant and researched characteristics of honey is its multifactorial antibacterial activity. Several antibacterial compounds have been identified including hydrogen peroxide (H2O2). The goal of the study was to characterize the antibacterial potential of honeys from various botanical origins (n = 233) against Staphylococcus aureus and Pseudomonas aeruginosa and establish the H2O2 content. Five types of honey were identified: acacia (n = 72), linden (n = 23), rapeseed (n = 9), sunflower (n = 8) and multi-floral (n = 121). The overall antibacterial activity of all the honey samples, expressed as a minimal inhibitory concentration of honey, strongly correlated with the level of H2O2. On the other hand, linden honey, which exhibited the strongest antibacterial effect, showed weak or no correlation between the antibacterial activity and the level of H2O2, depending on bacterial strain. The weakest antibacterial activity was documented in the rapeseed honey samples and it was associated with the low content of H2O2. These data suggest that antibacterial activity of honey is mainly H2O2-dependent; however, certain type of honey such as linden honey, showed a strong antibacterial effect which, may be, at least partially, attributed to non-peroxide factor(s).Hide Abstract
Surface modification of polyester fabric using plasma-dendrimer for robust immobilization of glucose oxidase enzyme.
Morshed, M. N., Behary, N., Bouazizi, N., Guan, J., Chen, G. & Nierstrasz, V. (2019). Scientific Reports, 9(1), 1-16.
Robust immobilization of glucose oxidase (GOx) enzyme was achieved on poly(ethylene terephthalate) nonwoven fabric (PN) after integration of favourable surface functional groups through plasma treatments [atmospheric pressure-AP or cold remote plasma-CRP (N2 + O2)] and/or chemical grafting of hyperbranched dendrimers [poly-(ethylene glycol)-OH or poly-(amidoamine)]. Absorption, stability, catalytic behavior of immobilized enzymes and reusability of resultant fibrous bio-catalysts were comparatively studied. Full characterization of PN before and after respective modifications was carried out by various analytical, instrumental and arithmetic techniques. Results showed that modified polyester having amine terminal functional groups pledged better surface property providing up to 31% enzyme loading, and 81% active immobilized enzymes. The activity of the enzyme was measured in terms of interaction aptitude of GOx in a given time to produce hydrogen peroxide using colorimetric assay. The immobilized GOx retained 50% of its original activity after being reused six (06) times and exhibited improved stability compared with the free enzyme in relation to temperature. The reaction kinetics, loading efficiency, leaching, and reusability analysis of enzyme allowed drawing a parallel to the type of organic moiety integrated during GOx immobilization. In addition, resultant fibrous bio-catalysts showed substantial antibacterial activity against pathogenic bacteria strains (Staphylococcus epidermidis and Escherichia coli) in the presence of oxygen and glucose. These results are of great importance because they provide proof-of-concept for robust immobilization of enzymes on surface-modified fibrous polyester fabric for potential bio-industrial applications.Hide Abstract
A single 48 mg sucralose sip unbalances monocyte subpopulations and stimulates insulin secretion in healthy young adults.
Gómez-Arauz, A. Y., Bueno-Hernández, N., Palomera, L. F., Alcántara-Suárez, R., De León, K. L.,Méndez-García, L. A., .Carrero-Aguirre, M., Manjarrez-Reyna, A. N., Martínez-Reyes, C. P., Esquivel-Velázquez, M., Ruiz-Barranco, A., Baltazar-López, N., Islas-Andrade, S., Escobedo, G. & Meléndez, G. (2019). Journal of Immunology Research, 2019, 6105059.
Sucralose is a noncaloric artificial sweetener that is widely consumed worldwide and has been associated with alteration in glucose and insulin homeostasis. Unbalance in monocyte subpopulations expressing CD11c and CD206 hallmarks metabolic dysfunction but has not yet been studied in response to sucralose. Our goal was to examine the effect of a single sucralose sip on serum insulin and blood glucose and the percentages of classical, intermediate, and nonclassical monocytes in healthy young adults subjected to an oral glucose tolerance test (OGTT). This study was a randomized, placebo-controlled clinical trial. Volunteers randomly received 60 mL water as placebo (n = 20) or 48 mg sucralose dissolved in 60 mL water (n = 25), fifteen minutes prior to an OGTT. Blood samples were individually drawn every 15 minutes for 180 minutes for quantifying glucose and insulin concentrations. Monocyte subsets expressing CD11c and CD206 were measured at -15 and 180 minutes by flow cytometry. As compared to controls, volunteers receiving sucralose exhibited significant increases in serum insulin at 30, 45, and 180 minutes, whereas blood glucose values showed no significant differences. Sucralose consumption caused a significant 7% increase in classical monocytes and 63% decrease in nonclassical monocytes with respect to placebo controls. Pearson’s correlation models revealed a strong association of insulin with sucralose-induced monocyte subpopulation unbalance whereas glucose values did not show significant correlations. Sucralose ingestion decreased CD11c expression in all monocyte subsets and reduced CD206 expression in nonclassical monocytes suggesting that sucralose does not only unbalance monocyte subpopulations but also alter their expression pattern of cell surface molecules. This work demonstrates for the first time that a 48 mg sucralose sip increases serum insulin and unbalances monocyte subpopulations expressing CD11c and CD206 in noninsulin-resistant healthy young adults subjected to an OGTT. The apparently innocuous consumption of sucralose should be reexamined in light of these results.Hide Abstract
Flexible and expeditious assay for quantitative monitoring of alpha-amylase and amyloglucosidase activities.
Oliveira, H. M., Pinheiro, A. Q., Fonseca, A. J., Cabrita, A. R. & Maia, M. R. (2019). MethodsX, 6, 246-258.
studying their role in the hydrolysis of starch. Here we introduced an improved method capable to measure the activity of alpha-amylase and amyloglucosidase from different sources based on a quantitative starch-iodine assay. The developments of the assay sought the consistent preparation of the reagents, the rescale of the assay and the adjustment of the sensitivity. This was complemented by a glucose yield assay for amyloglucosidase that allowed a secondary source of information when insoluble starches were studied. The proposed method showed high precision in long-term use (RSD < 6.3%). Furthermore, all experimental conditions can be adapted according to the equipment available at each laboratory, transforming this method in a broadband analytical tool for screening alpha-amylase and amyloglucosidase activities.Hide Abstract
Surface modification of carbon felt by cold remote plasma for glucose oxidase enzyme immobilization.
Kahoush, M., Behary, N., Cayla, A., Mutel, B., Guan, J. & Nierstrasz, V. (2019). Applied Surface Science, 476, 1016-1024.
Despite their chemical inertness and poor hydrophilicity, carbon-based materials are widely used in electrochemical applications due to their robustness, good electrical conductivity and corrosion resistance. The purpose of the work carried was to increase the wettability of nonwoven carbon fiber felts for improved efficiency in bio/electrochemical applications. Virgin Carbon Felt (VCF) was first treated with cold remote plasma (CRP) using a mixture of nitrogen and oxygen (1 or 2%) as plasma gas. Bio-functionalization of the carbon felts with glucose oxidase (GOx) enzyme was then carried using physical adsorption method. FTIR and XPS analysis showed an integration of new oxygenated functional groups (C-O and C=O) as well as amines and amides on the surface of VCF treated by the CRP treatment, which improved the wettability of the samples. Capillary uptake increased from around 0% (for VCF) to nearly 750% with 2% oxygen in plasma gas. GOx enzyme showed higher activity after immobilization at pH 5.5 on the CRP treated samples, maintaining up to 50% of its initial enzymatic activity after six cycles while with the VCF, no enzymatic activity was observed after the fourth cycle. These obtained felts can be used as electrodes in sustainable bioprocesses.Hide Abstract