Starch Loading Research Articles

Effects of brown seaweeds on postprandial glucose, insulin and appetite in humans – A randomized, 3-way, blinded, cross-over meal study

Seaweed including brown seaweeds with rich bioactive components may be efficacious for a glycaemic management strategy and appetite control. We investigated the effects of two brown edible seaweeds, Laminaria digitata (LD) and Undaria pinnatifida (UP), on postprandial glucose metabolism and appetite following a starch load in a human meal study. Twenty healthy subjects were enrolled in a randomized, 3-way, blinded cross-over trial. The study was registered under ClinicalTrials.gov Identifier no. NCT00123456. At each test day, the subjects received one of three meals comprising 30g of starch with 5g of LD or UP or an energy-adjusted control meal containing pea protein. Fasting and postprandial blood glucose, insulin, C-peptide and glucagon-like peptide-1 (GLP-1) concentrations were measured. Subjective appetite sensations were scored using visual analogue scales (VAS). Linear mixed model (LMM) analysis showed a lower blood glucose, insulin and C-peptide response following the intake of LD and UP, after correction for body weight. Participants weighing≤63kg had a reduced glucose response compared to control meal between 40 and 90min both following LD and UP meals. Furthermore, LMM analysis for C-peptide showed a significantly lower response after intake of LD. Compared to the control meal, GLP-1 response was higher after the LD meal, both before and after the body weight adjustment. The VAS scores showed a decreased appetite sensation after intake of the seaweeds. Ad-libitum food intake was not different three hours after the seaweed meals compared to control. Concomitant ingestion of brown seaweeds may help improving postprandial glycaemic and appetite control in healthy and normal weight adults, depending on the dose per body weight. Clinicaltrials.gov (ID# NCT02608372).

Effect of Tacca Starch Loading on Production of Amylolytic Enzymes from Ragi Tapai

The study was done to determine the effect of Tacca starch loading on production of amylolytic enzyme from Ragi Tapai. In this study, Ragi Tapai was used as a starter to produce amylolytic enzyme. The fermentation was done in a solid state fermentation with the presence ofTacca leontopetaloidesstarch as the carbon source. The analysis of total sugar was conducted using DNS method and amylolytic enzyme was determined using Lowry method. The mixture was fermented and incubated for 24, 48, 72 and 96h. The result revealed that the optimum production of amylase was found at 48 h of incubation with amylase activity of 1.91 U/ml/min and 1.42 mg/ml for total protein. The study shows that increment amount of the Tacca starch in cultivation medium, increase the production of the amylase and total protein content. The highest enzyme activity was obtained at 4% of Tacca starch loading with amylase activity and total protein content of 2.14 U/ml/min and 1.42 mg/ml respectively. The study indicated that growth promoters in Tacca starch capable to enhance the activity of microbial consortium in Ragi Tapai for production of the amylolytic enzyme.

Copy Number Variation of the Salivary Amylase Gene and Glucose Metabolism in Healthy Young Japanese Women.

BackgroundMany studies have shown that low copy number variation (CNV) of the salivary amylase gene (AMY1) and low serum amylase concentration are associated with impaired glucose metabolism and obesity. We aimed to clarify the conflicting results of previous studies by examining AMY1 expression and metabolic indices in a homogenous group of healthy participants.MethodsSixty healthy non-obese young Japanese women aged 20 - 39 years were examined for AMY1 CNV, salivary amylase, body mass index (BMI) and serum parameters including glycated hemoglobin (HbA1c), ketones, and total, salivary and pancreatic amylase. Respiratory quotient at rest and changes in blood glucose after starch loading were also examined.ResultsAMY1 CNV (range, 4 - 14) and the level of serum salivary amylase were correlated inversely with HbA1c (r = -0.36, P = 0.003 and r = -0.30, P = 0.02, respectively), whereas the percentage of serum salivary amylase in total serum amylase was positively correlated with blood glucose at 30 and 45 min after starch loading (r = 0.38, P = 0.004 and r = 0.27, P = 0.04, respectively). The level of serum total amylase, but not AMY1 CNV, was correlated inversely with BMI (r = -0.29, P = 0.02). Logistic regression analysis showed that low AMY1 CNV (4 - 7) was significantly associated with an HbA1c of ≥ 5.4% (34 mmol/mol) even after adjustment for age, BMI and energy consumption, compared with high AMY1 CNV (8 - 14).ConclusionsAlthough a higher percentage of serum salivary amylase was associated with higher levels of blood glucose at the early stage after starch loading, low AMY1 CNV was associated with chronic unfavorable glucose metabolism in healthy non-obese young women in Japan.

BIOCONVERSION OF STARCH TO MALTOOLIGOSACCHARIDES (MOS) BY THE REACTION OF MALTOGENIC AMYLASE

Maltogenic amylase is one of the significant enzymes in oligosaccharides synthesis. Its ability to utilise multiple substrates and catalyse hydrolysis and transglycosylation reactions simultaneously makes it a unique biocatalyst. The catalysis could be exploited in many ways to obtain oligosaccharides of different lengths and various modified sugars. Nonetheless, one of the major drawbacks of substrate hydrolysis to produce oligosaccharides is the low production of MOS with higher degree of polymerisation. To address this issue, reaction parameter optimisation was performed via one-factor-at-a-time (OFAT) approach on the production of MOS from soluble starch hydrolysis using maltogenic amylase from Bacillus lehensis G1 (MAG1). Optimisation of MAG1 loading, soluble starch loading, temperature, time and pH resulted in the production of 84.87 mg/g MOS with polymerisation degree of 3 to 7 compared to that of 51.60 mg/g obtained before the optimisation process, which recorded 1.64-fold increment. Among all parameters, soluble starch loading gave the most significant impact on the MOS production as the reaction equilibrium is highly affected by substrate concentration. The occurrence of MOS with polymerisation degree of 4 and above, which resulted from starch hydrolysis further confirms the endo-type of MAG1. Because starch is an abundant and inexpensive source of carbohydrate in the world, this study provides a cost-effective MOS production process which is highly relevant for industry.

Recovery of starch from cassava bagasse for cyclodextrin production by sequential treatment with α-amylase and cyclodextrin glycosyltransferase

Abstract This work aimed at the enzymatic recovery of starch from cassava bagasse using α-amylase and the production of cyclodextrins (CDs) by cyclodextrin glycosyltransferase (CGTase). Cassava bagasse containing 50% (w/w) starch (dry basis) was hydrolyzed by α-amylase until a maximum starch recovery as a maltooligosaccharide solution. Afterwards, this solution was used for the production of CDs using CGTase as biocatalyst. Optimal conditions for starch extraction using α-amylase were 60 °C and 0.15 mL enzyme/kg dry bagasse, with 93% starch recovery. Several operational parameters were evaluated to optimize the CD yields, such as starch dextrose equivalent (DE), temperature and CGTase loading. The starch DE did not significantly influence the production of CDs, resulting in a similar yield for all experiments (43%). The highest productivity of CDs (93.6 mg of CDs per enzyme Unit) was obtained using an enzyme loading of 2.5 U/g starch for 1 h at 60 °C and pH 6.0. After 6 h of reaction at 60 °C and pH 6.0, the CD yield reached a value of 50%. These findings did indicate that cassava bagasse is a promising feedstock for the production of CDs using this bi-enzymatic system.

Surface Treatment of Superabsorbent Polymer with Corn Starch for Improved Properties

Samples of superabsorbent polymer (SAP) were treated with corn starch to modify absorption and permeability properties. The process was done by homogenously mixing the superabsorbent polymer particles with starch suspension using starch loading of 0.002-0.20 g of starch per g of SAP. The resulting mixture was then dried at temperature of 150oC. The absorption properties such as Free Swell Capacity (FSC) and Absorption Under Pressure (AUP) of treated SAP were determined at different starch loading using test solution of varying sodium chloride concentrations and compared with the untreated SAP. At starch loading of 0.04 g/g, AUP gave better results than untreated SAP. GLP of treated SAP gave significant improvement which is explained in terms of the controlled swelling of SAP particles and a more porous structure of the SAP gel layer that allows faster liquid flow rate.

Effect of Hydroxyethyl Starch Loading on Glycocalyx Shedding and Cerebral Metabolism During Surgery

BackgroundFluid therapy influences glycocalyx shedding; however, the effect of this intervention on glycocalyx shedding in patients with glioma remains unclear. In this study, we have investigated glycocalyx shedding and cerebral metabolism during colloid loading in patients with and without glioma. MethodsForty patients undergoing general anesthesia were assigned to the glioma brain group (n = 20) or the normal brain group (n = 20); patients in the normal brain group were undergoing partial hepatectomy to treat liver cancer. All patients were subjected to 15 mL/kg hydroxyethyl starch (HES) loading after the induction of anesthesia. Glycocalyx shedding, reflected by syndecan-1 and heparan sulfate levels at the jugular venous bulb, was measured in both groups. We also evaluated cerebral metabolism parameters, including jugular venous oxygen saturation (SjvO2), arterial-jugular venous differences in oxygen (CajvO2), glucose (A-JvGD), lactate (A-JvLD), the cerebral extraction ratio for oxygen (CERO2), and the oxygen-glucose index. ResultsOur results showed that patients in the glioma brain group had lower preoperative basal syndecan-1 shedding in plasma than patients in the normal brain group. The hematocrit (Hct)-corrected syndecan-1 level was significantly increased after 15 mL/kg HES fluid administration (19.78 ± 3.83 ng/mL) compared with the Hct-correct baseline syndecan-1 level (15.67 ± 2.35 ng/mL) in patients in the glioma brain group. Similarly, for patients in the normal brain group, Hct-corrected syndecan-1 level was significantly increased after HES loading (34.71 ± 12.83 ng/mL) compared with the baseline syndecan-1 level (26.07 ± 12.52 ng/mL). However, there were no intergroup or intragroup differences in Hct-corrected heparan sulfate levels at any time point. Our study also showed that the SjvO2 was lower and CajvO2 and CERO2 were higher in the glioma brain group at 30 min after HES loading. Intragroup analysis showed that CERO2 and CajvO2 increased after general anesthesia compared with the baseline values in the glioma brain group. In contrast, cerebral metabolism in the normal brain group was unchanged during perioperative period. There were no significant differences in oxygen-glucose index between the two groups throughout the study period. ConclusionsPreoperative 15 mL/kg HES loading had similar effects on systemic glycocalyx shedding in both the glioma brain and normal brain groups, although patients in the normal brain group had higher levels of plasma syndecan-1. Furthermore, the intraoperative anesthetic management may substantially influence cerebral metabolism in patients with glioma.

Evaluation of morphological, mechanical, and rheological properties of vulcanized styrene–butadiene rubber/modified corn starch blends

The starch-filled styrene–butadiene rubber (SBR) was prepared using a laboratory-sized two-roll mill. Starch was modified by yeast fermentation for 1 day before it was blended with SBR. The hydrophilicity of SBR was enhanced by grafting with modified starch (MST) by utilizing tetramethyl thiuram disulfide as a catalyst. The effect of modified corn starch loading on morphological, mechanical, and rheological properties of vulcanized SBR blends was investigated. Scanning electron microscope result revealed that the adhesion between the MST and SBR was weak, and the starch pulled out due to poor interfacial bonding. The lowest ultimate tensile strength, elongation at break, and tensile modulus of the SBR- g-MST were found in the sample containing 150 phr of starch. The variation of the percentage elongation of neat rubber and MST/rubber composites was 91.34%. The significant decrease in cure times was observed with the loading of MST in all blends up to 100 phr starch, while no significant change in scorch time was observed. The maximum torque, minimum torque, and cross-linking density increased as the starch loading increases up to 100 phr MST. The water absorption by the composite increases with immersion time and MST loading, although the rate of absorption decreases with increased time. The current product could be especially advantageous in agricultural and horticultural applications as a good controlled fertilizer release and for water retention.

Swelling kinetics and characterization of novel superabsorbent polymer composite based on mung bean starch-filled poly(acrylic acid)-graft-waste polystyrene

A novel superabsorbent polymer composite based on mung bean starch was prepared via emulsion polymerization technique of partially neutralized acrylic acid grafted onto waste polystyrene chain using ammonium persulfate and N,N′-methylenebisacrylamide as initiator and crosslinker, respectively. Fourier transform infrared confirmed the presence of mung bean starch in the grafting of polyacrylic acid and waste polystyrene. The introduction of starch in superabsorbent polymer greatly enhanced the swelling capacity with the optimum absorbency recorded at 59.3 g/g for 20% of starch loading. Meanwhile, thermogravimetric analysis showed enhance in thermal stability upon incorporation of mung bean starch.

Starch Coated Silica Nanospheres Parenting the Growth of Trimodal Porous Zeolites for Catalysis Involving Large Molecules

A simple method for the synthesis of nanocrystalline ZSM-5 and Beta zeolites with trimodal porosity was developed using starch coated silica nanospheres (as silica precursor) for generating interparticle porosity (50–200 nm); propyltriethoxysilane was used as an additive for generating intercrystalline mesopores (2–50 nm) in the presence of microporous zeolite porogen. Loading of starch and propyltriethoxysilane additive played a pivotal role in obtaining trimodal porosity with very small size zeolite nanoparticles having high surface area and pore volume. The possible growth mechanism for the fabrication of trimodal porous zeolite is presented. The resultant zeolite demonstrated excellent acidity and activity in the liquid phase acid catalyzed reactions such as esterification of hexanoic/oleic acid with benzyl alcohol, condensation of benzaldehyde and 2-hydroxyacetophenone, and Friedel–Crafts alkylation followed by ring closure reaction for the synthesis of vitamin E when compared to conventional zeolite with excellent recyclability. Such an economical starch mediated synthesis strategy can be extended to other zeolite frameworks and similar heterogeneous catalytic materials.

Preparation, characterization and in vitro evaluation of melatonin-loaded porous starch for enhanced bioavailability

The present work aimed to apply porous starch (PS) as carrier to improve the oral bioavailability of poorly soluble drug melatonin (MLT). The drug loading and encapsulation efficiency of MLT-loaded porous starch (MPS) were optimized. The characteristics of MPS were analyzed using scanning electron microscopy, Brunauer–Emmett–Teller surface area, Fourier–transform infrared spectroscopy, x-ray diffraction, differential scanning calorimetry and thermo gravimetric analysis. Most MLT transformed into their amorphous form in the PS pores. MPS showed higher MLT solubility and cumulative release rate compared with raw MLT in SGF and SIF. MPS exhibited a higher inhibition to DCFH–DA-oxidized peroxyl radicals at a lower EC50 than that of the raw MLT. Furthermore, the plasma concentrations of MLT and MPS reached a Cmax of 134.26 and 291.77 ng/mL at 15 and 20 min, respectively. The AUC0–360min of the formulated MPS-treated group was approximately 2.34-fold higher than that of raw MLT.

Effects of Dynamic Vulcanization on Properties of Polypropylene/Natural Rubber/Thermoplastic Starch Blends

The effects of thermoplastic starch (TPS) loading on polypropylene (PP)/natural rubber (NR) blend vulcanized with N, N’-m-phenylene bismaleimide (HVA-2) were investigated. Thermoplastic starch ratios was varied at 5%,10%,20% and 30% weight percentage in order to imparted biodegradable properties into PP/NR blends. The study has focused on the thermoplastic starch loading and blend’s modification on the mechanical properties, morphology and biodegradable properties of PP/NR blends. This study showed that the tensile properties of the PP/NR blends were deteriorated with increasing in TPS content. The dynamic vulcanization by using HVA-2 crosslinker was applied on the blends in order to compensate the deterioration properties caused by incorporation of TPS. According to the results, the HVA-2 crosslinker showed the increasing in tensile properties as well as better morphology analysis as compared to unvulcanized counterparts. On top of that, the scanning electron microscopy (SEM) studied also found that the interfacial adhesion and dispersion of TPS was improved upon HVA-2 vulcanized in PP/NR blends. Microscope images after soil burial test show that the HVA-2 crosslinker has delayed the biodegradability of PP/NR/TPS blends.

Optimisation of Formulation for Starch Modified Natural Rubber Composites by Using Response Surface Methodology

Starch modified natural rubber vulcanisates were prepared by the melt compounding method using a two-roll mill at a constant starch loading of 20 phr. Four formulation parameters consisted of black filler, white filler, silane coupling agent (SCA) and glycerol content in the composites which were optimised using two-level factorial design via response surface methodology (RSM). The cure characteristics and rebound resilience were selected as the responses. The significance of the factors and interaction were analysed using ANOVA and the model’s ability to represent the system was confirmed using the constant of determination, R2 for a value above 0.90. The R2 values for all responses were obtained in the range between 0.96 and 0.99 which are close to the union (R2 = 1). The final combination of factors used to achieve the highest rebound resilience and cure characteristics were with a high black filler loading of 60 phr and high glycerol of 5 % loading. These findings were further supported by morphological the characteristics observed under scanning electron microscopy (SEM). Therefore, the chemical modification using both glycerol and SCA was proven to improve the cure characteristics and rebound resilience value through the enhancement of the interfacial interaction between the starch and natural rubber (NR) particles. It is expected that the findings in this study will be useful for rubber product manufacturers to explore the possibility of producing biodegradable products in the future.

Uptake Fluoride from Water by Starch Stabilized Layered Double Hydroxides

A novel starch stabilized Mg/Al layered Double hydroxides (S-LDHs) was prepared in a facile approach and its fluoride ion removal performance was developed. Characterization of S-LDHs was employed by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and particle size distribution. The adsorption property was studied through the assessment of the adsorption isotherms, kinetic models, thermal dynamics, and pH influence. The result shows that a low loading of starch of 10 mg onto layered double hydroxides (LDHs) could obviously improve the fluoride removal rate. The S-LDHs had three times higher the adsorption capacity to fluoride than that of Mg/Al LDHs to fluoride. The particle size was smaller and the particle size distribution was narrower for S-LDHs than that for Mg/Al LDHs. The Langmuir adsorption isotherm model and pseudo-second-order kinetic model fitted well with the experimental data. In thermodynamic parameters, the enthalpy (ΔH0) value was 35.63 kJ·mol−1 and the entropy (ΔS0) value was 0.0806 kJ·mol−1K−1. The values of ΔG0 were negative, implying the adsorption process is spontaneous. S-LDHs reveals stable adsorption property in a wide pH range from 3 to 9. The mechanism for fluoride adsorption on S-LDHs included surface adsorption and interaction ion exchange.

Calorie Restriction Effect of Heat-Processed Onion Extract (ONI) Using In Vitro and In Vivo Animal Models.

Onion (Allium cepa L.) is widely consumed as food or medicinal plant due to its well-defined health benefits. The antioxidant and antihyperlipidemic effects of onion and its extracts have been reported well. However, very limited information on anti-hyperglycemic effect is available in processed onion extracts. In our previous study, we reported that Amadori rearrangement compounds (ARCs) produced by heat-processing in Korean ginseng can reduce carbohydrate absorption by inhibiting intestinal carbohydrate hydrolyzing enzymes in both in vitro and in vivo animal models. To prove the enhancement of anti-hyperglycemic effect and ARCs content by heat-processing in onion extract, a correlation between the anti-hyperglycemic activity and the total content of ARCs of heat-processed onion extract (ONI) was investigated. ONI has a high content of ARCs and had high rat small intestinal sucrase inhibitory activity (0.34 ± 0.03 mg/mL, IC50) relevant for the potential management of postprandial hyperglycemia. The effect of ONI on the postprandial blood glucose increase was investigated in Sprague Dawley (SD) rats fed on sucrose or starch meals. The maximum blood glucose levels (Cmax) of heat-processed onion extract were significantly decreased by about 8.7% (from 188.60 ± 5.37 to 172.27 ± 3.96, p < 0.001) and 14.2% (from 204.04 ± 8.73 to 175.13 ± 14.09, p < 0.01) in sucrose and starch loading tests, respectively. These results indicate that ARCs in onion extract produced by heat-processing have anti-diabetic effect by suppressing carbohydrate absorption via inhibition of intestinal sucrase, thereby reducing the postprandial increase of blood glucose. Therefore, enhancement of ARCs in onion by heat-processing might be a good strategy for the development of the new product on the management of hyperglycemia.

Rheological characterization and modeling of vulcanization kinetics of natural rubber/starch blends

ABSTRACTVulcanization kinetics of natural rubber/starch (NR/ST) blends was investigated by oscillating disc rheometer. The scorch and cure times are significantly reduced with the loading of starch in all blends from 1.15 and 2.22 to 0.91 and 1.88 min, respectively, to improve curing rate. Meanwhile, the maximum torque values and the maximum vulcanization rate of NR/ST blend increase with the starch loading from 1.51 N m and 0.387 min−1 to 2.224 N m and 0.492 min−1 respectively. The results of vulcanization kinetics of NR and its blends revealed that it is controlled by two‐stages, chemical and diffusion. The experimental data of the vulcanization rate of NR/ST blends did not fit with autocatalytic kinetic model except the pure natural rubber. Therefore, the Criado method was used and it was observed that the reaction kinetic model of pure NR and its blends with starch is best described by the D diffusion model (D2). © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46347.

Controlled Microwave-Hydrolyzed Starch as a Stabilizer for Green Formulation of Aqueous Gold Nanoparticle Ink for Flexible Printed Electronics

Gold electrodes are important in some devices and certain applications where an inert, highly conductive feature is required. An aqueous gold nanoparticle (AuNP) ink suitable for inkjet printing was synthesized and formulated using starch and microwave-assisted heating. By varying the hydrolysis conditions of starch, the size, yield, and stability of the AuNP suspension can be controlled and optimized to achieve a jettable ink. The optimized formulation has a very low starch loading of only 1.75 wt % relative to gold, forming a highly stable AuNP ink, which upon drying already forms a very conductive film and sinters at low temperature. The overall synthesis protocol thus provides a greener and cheaper alternative to other AuNP synthesis methods. The sintering behavior of the film was monitored, wherein, upon heating, starch is degraded, crystallite growth increased, and the morphology changed from individual nanoparticles to a network of fused particles. The film sheet resistance decreased concomitant wi...

Effect of cortex mori on pharmacokinetic profiles of main isoflavonoids from pueraria lobata in rat plasma

Ethnopharmacological relevanceRadix pueraria (the root of pueraria lobata (Wild.) Ohwi.), which contains a class of isoflavonoids as the main active components, as well as cortex mori (the root bark of Morus alba L), which contains abundant active alkaloids, have been employed for the treatment of diabetes in traditional Chinese medicine for centuries. In previous studies, pharmacodynamic synergistic reactions have been observed in compatible application of pueraria lobata isoflavonoids extracts (PLF) and cortex mori alkaloids extracts (CME) for inhibiting α-glycosidase activity. It has also been demonstrated that PLF can effectively slow down the absorption of active alkaloid from CME, so as to produce a higher effective concentration in small intestine for depressing the elevation of postprandial blood glucose through inhibiting α-glycosidase activity. Aim of the studyIn this study, the hypoglycemic effect of PLF, CME or CME-PLF mixture (the mixture of CME and PLF at a ratio of 1:6.3) was further evaluated through in vivo glucose tolerance studies. And the effect of CME on pharmacokinetic profiles of main isoflavonoids from PLF in rat plasma was investigated to further underlie compatibility mechanism of the two herbs. Materials and methodsFour groups of rats received an oral dose of starch solution alone or simultaneously with drugs by gavage feeding. The blood samples were collected to determine glucose concentrations by glucose oxidase method. In addition, another two groups of rats were orally administered with PLF or CME-PLF. The plasma samples were collected and assayed using an LC/MS/MS method for comparatively pharmacokinetic studies of five main isoflavonoids. ResultsFor starch loading, co-administration of CME-PLF resulted in more potent inhibition effects on glucose responses compared to those by CME or PLF in rat. The isoflavonoids from PLF were rapidly absorbed, presenting similarly low concentrations in plasma. When CME was added, the Cmax and AUC of all the five isoflavonoids were increased. A phenomenon of double peaks was found for all analysts. The elimination rates of all the detected isoflavonoids were also slowed down with extension of t1/2. ConclusionsCME has been found to increase the absorption and delay the elimination of main isoflavonoids from PLF, which might result in higher concentrations of circulating active compounds for anti diabetes.

Effect of Starch Loading on the Thermo-Mechanical and Morphological Properties of Polyurethane Composites.

The advancements in material science and technology have made polyurethane (PU) one of the most important renewable polymers. Enhancing the physio-chemical and mechanical properties of PU has become the theme of this and many other studies. One of these enhancements was carried out by adding starch to PU to form new renewable materials called polyurethane-starch composites (PUS). In this study, PUS composites are prepared by adding starch at 0.5, 1.0, 1.5, and 2.0 wt.% to a PU matrix. The mechanical, thermal, and morphological properties of PU and PUS composites were investigated. Scanning electron microscope (SEM) images of PU and PUS fractured surfaces show cracks and agglomeration in PUS at 1.5 wt.% starch. The thermo-mechanical properties of the PUS composites were improved as starch content increased to 1.5 wt.% and declined by more starch loading. Despite this reduction, the mechanical properties were still better than that of neat PU. The mechanical strength increased as starch content increased to 1.5 wt.%. The tensile, flexural, and impact strengths of the PUS composites were found to be 9.62 MPa, 126.04 MPa, and 12.87 × 10−3 J/mm2, respectively, at 1.5 wt.% starch. Thermal studies showed that the thermal stability and crystallization temperature of the PUS composites increased compared to that of PU. The loss modulus curves showed that neat PU crystallizes at 124 °C and at 127 °C for PUS-0.5 wt.% and rises with increasing loading from 0.5 to 2 wt.%.

Pre-clinical evidence for the efficacy and safety of α-amylase inhibitory peptides from cumin (Cuminum cyminum) seed

Inhibitor of α-amylase offers an effective strategy to modulate hyperglycemia. Three novel cumin-seed peptides (CSPs) were proposed as potent inhibitors according to previous study. This study was performed to further assess the clinical relevance of CSPs in simulated physiological conditions via an in vitro model using AR42J α-amylase secretory cells. The CSPs displayed dose-dependent manners for bioactivities and cytotoxic responses. The IC50 values for inhibition were 5.6, 1.58, and 2.39mg/ml, for CSP3, CSP4 and CSP6, respectively. The following starch load test further confirmed the efficiencies of CSPs as potent α-amylase inhibitor, as they were found capable of retaining more than 50% of their initial inhibition upon 2h treatment. In addition, CSPs displayed mixed-type inhibition patterns with respect to soluble substrate (∼7.3–29.2mM), suggesting that these peptide inhibitors have multiple binding modes to α-amylase. Therefore, CSPs exhibit promising potentials for development as new agents for the treatment of diabetic.