Slowly digestible sweetpotato flour: Preparation by heat-moisture treatment and characterization of physicochemical properties

The preparation and physicochemical characteristics of sweetpotato flour with increased slowly digestible starch (SDS) fraction were investigated under various heat-moisture treatment (HMT) conditions. The optimum conditions for preparing slowly digestible sweetpotato flour established using response surface methodology were moisture content of 22%, temperature of 103°C, and treatment time of 5.8 h. The highest SDS content in heat-moisture treated sweetpotato flour was 57.6%. The relative crystallinity of heat-moisture treated sweetpotato flour decreased, but the X-ray diffraction pattern maintained the A-type. The DSC of the heatmoisture treated flour showed a decreased gelatinization temperature range and gelatinization enthalpy compared with native one. The viscosity profiles and values changed significantly with HMT, resulting in a higher pasting temperature, decrease of the viscosity values, and no breakdown. It indicates that heat-moisture treated sweetpotato flour is more stable at high temperatures and shear rates than native one.     

Flavonoid glycosides from cowpea seeds (Vigna sinensis K.) inhibit LDL oxidation

Six flavonoid glycosides were isolated from the n-butanol fraction of cowpea seeds (Vigna sinensis K.) through silica gel (SiO₂) and octadecyl silica gel (ODS) column chromatographies. Based on their chemical structures determined via interpretation of spectroscopic data including NMR, MS, and IR, the compounds were identified as kaempferol 3-O-β-d-sophoroside (1), quercetin 3-O-β-d-sophoroside (2), isoquercitrin (3), hyperin (4), catechin 7-O-β-d-glucopyranoside (5), and quercetin 3-O-β-Dglucopyranosyl( 1→6)-O-β-d-galactopyranoside (6). This is the first report of the isolation of these flavonoids from this plant. Among these flavonoids, compound 2, 5, and 6 significantly inhibited LDL oxidation exhibiting 96.0±0.1 (IC₅₀: 3.9 μM), 96.8±1.7 (IC₅₀: 2.9 μM), and 97.4±0.1% (IC₅₀: 3.5 μM) inhibition, respectively, at a concentration of 40 μM.     

Three-year atmospheric monitoring of organochlorine pesticides and polychlorinated biphenyls in polar regions and the South Pacific

XAD-2 resin based passive air samplers (PAS) were deployed for three one-year periods at the Korean polar and South Pacific research stations at Ny-?lesund (2005-2009), King George Island (2005-2007), and Chuuk (2006-2009) to investigate long-range transport, local sources, and temporal trends of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The highest hexachlocyclohexane (HCH) concentration (35.2-78.9 pg·m(-3)) over the entire sampling period was detected at Ny-?lesund, in the Arctic. α-HCH was the dominant OCP (31.1-67.1 pg·m(-3)), contributing about 50% of the total OCP load. Additionally, a high and consistent α/γ-HCH ratio was observed at Ny-?lesund. HCHs might reach Arctic sites more easily than other OCPs from surrounding countries through long-range atmospheric transport (LRAT). Interestingly, high levels of the current-use OCP endosulfan-particularly endosulfan-I--were detected at almost all sampling sites, including in Antarctica, ranging 12.2-88.5, 17.7-130, and ND-59.7 pg·m(-3) at King George Island, Ny-?lesund, and Chuuk, respectively. Specific OCP and PCB patterns, such as low trans/cis-chlordane ratios and a prevalence of lighter PCB congeners, were observed in all three regions (excepting one site at Ny-?lesund and one site in the South Pacific affected by local sources) during all sampling periods. This indicates that these Polar and remote South Pacific sites are mainly influenced by LRAT. Over the entire sampling period, a decreasing trend of HCHs (α- and γ-HCH) and an increasing trend of endosulfan-I were observed at the Ny-?lesund sites.     

Starch source evaluation in calf starter: II. Ruminal parameters, rumen development, nutrient digestibilities, and nitrogen utilization in Holstein calves

Ruminal parameters, rumen development, nutrient digestibilities, and N utilization were estimated in Holstein calves fed starch from different sources. Ground corn, ground barley, ground wheat, and crimped oats were used to formulate 4 isostarch (25% of starter dry matter) pelleted diets. These diets were randomly allocated to calves (16 calves per treatment, 8 female and 8 male) and fed ad libitum along with mixed grass hay throughout the experiment. Ruminal contents and blood were sampled at d 35, 50, and 70 of age to estimate ruminal parameters and plasma β-hydroxybutyrate, respectively. At d 70, twenty-four male calves (6/treatment) were randomly selected, euthanized, and forestomach weight, papillae length (PL), papillae width (PW), rumen wall thickness (RWT), and papillae concentration were measured. At d 63, twenty-four female calves (6/treatment) were randomly selected and moved to metabolism stalls to estimate total tract apparent nutrient digestibilities and N utilization. Female calves were given 2 wk for adaptation to experimental facilities and then total collections of feces and urine were made from d 77 to 84 of age. Ruminal pH at d 35 of age was higher in calves fed corn and oat diets than in those fed barley and wheat diets. Ruminal pH at d 50 and 70 of age was the lowest in calves on barley diets followed by those on oat and wheat diets and then by those on the corn diet. Ruminal total volatile fatty acid concentrations at d 35 of age were greatest in calves fed corn or wheat diets followed by those fed barley and oat diets. Calves on corn and wheat diets maintained greater ruminal volatile fatty acids concentrations at d 50 and 70 of age. Ruminal ammonia, acetate, propionate, butyrate, and blood β-hydroxybutyrate concentrations were also greater in calves on the corn and wheat diets. Full and empty weights of forestomach, PL, PW, RWT, and papillae concentrations were greater in calves on corn and wheat diets. Daily average intake of nutrients (dry matter, crude protein, neutral detergent fiber, starch, Ca, and P) was greater in calves fed corn and wheat diets than in those fed barley and oat diets. Starch source did not influence the total tract apparent digestibilities of nutrients in calves. Daily N retention (g/d) was greatest on the corn diet followed by the wheat diet and then the barley and oat diets. In conclusion, calves on a corn diet have greater ruminal capacity to accommodate feed bulk. More physically and metabolically functional rumens in calves on corn and wheat diets probably resulted in greater feed consumption and N retention.     

A Boronic Acid Assay for the Detection of Mucin‐1 Glycoprotein from Cancer Cells

Cell surface glycoproteins are commonly aberrant in disease and act as biomarkers that facilitate diagnostics. Mucin‐1 (MUC1) is a prominent example, exhibiting truncated glycosylation in cancer. We present herein a boronic acid microplate assay for sensitive and high‐throughput detection of such glycoproteins. The immobilization of biotin–boronic acid 1 onto streptavidin plates generated a multivalent surface for glycoprotein recruitment and detection. We first validated the binding properties of 1 in solution through titrations with alizarin dye. Next, the microplate assay was explored through horseradish peroxidase (HRP) analysis as a proof‐of‐concept glycoprotein with chemiluminescence detection. Finally, this platform was applied for the detection of MUC1 directly from MCF‐7 human breast cancer cell lysates by using an HRP‐tagged antibody that targets the cancerous form of this glycoprotein. Sensitive, dose‐dependent detection of MUC1 was observed, showcasing the efficacy of this platform for detecting disease‐associated glycoproteins.     

Metalloendopeptidase ADAM-like Decysin 1 (ADAMDEC1) in Colonic Subepithelial PDGFRα+ Cells Is a New Marker for Inflammatory Bowel Disease

Metalloendopeptidase ADAM-Like Decysin 1 (ADAMDEC1) is an anti-inflammatory peptidase that is almost exclusively expressed in the gastrointestinal (GI) tract. We have recently found abundant and selective expression of Adamdec1 in colonic mucosal PDGFRα⁺ cells. However, the cellular origin for this gene expression is controversial as it is also known to be expressed in intestinal macrophages. We found that Adamdec1 mRNAs were selectively expressed in colonic mucosal subepithelial PDGFRα⁺ cells. ADAMDEC1 protein was mainly released from PDGFRα⁺ cells and accumulated in the mucosal layer lamina propria space near the epithelial basement membrane. PDGFRα⁺ cells significantly overexpressed Adamdec1 mRNAs and protein in DSS-induced colitis mice. Adamdec1 was predominantly expressed in CD45⁻ PDGFRα⁺ cells in DSS-induced colitis mice, with only minimal expression in CD45⁺ CD64⁺ macrophages. Additionally, overexpression of both ADAMDEC1 mRNA and protein was consistently observed in PDGFRα⁺ cells, but not in CD64⁺ macrophages found in human colonic mucosal tissue affected by Crohn’s disease. In summary, PDGFRα⁺ cells selectively express ADAMDEC1, which is localized to the colon mucosa layer. ADAMDEC1 expression significantly increases in DSS-induced colitis affected mice and Crohn’s disease affected human tissue, suggesting that this gene can serve as a diagnostic and/or therapeutic target for intestinal inflammation and Crohn’s disease.     

Automatic heat-shrink sleeve applicator using the low-temperature catalytic combustor

Catalytic combustion for applying heat shrink sleeves (HSS) to a pipeline in KOGAS was investigated. We used a low temperature catalytic combustor in order to place HSS in the conduit. The surface temperature of the catalytic combustor maintained the conditions at which HSS can become well-adhesive at the conduit. Therefore, the automatic HSS construction provided the chance to establish gas pipeline safety by an automatic catalytic combustor device.     

Synthesis and characterization of new aromatic polyimides containing well‐defined conjugation units

A series of aromatic polyimides composed of well‐defined conjugation units were synthesized form 5,5′‐bis(4‐aminophenyl)‐2,2′‐bifuryl (PFDA) and 2,2′‐bis(furyl) benzidine (FurylBZ) with various dianhydrides. The synthesized polyimides emit blue to green light with a quantum yield of 7.3–14.9%, depending on the polymer backbone. In particular, PFDA‐based polymers exhibit extremely narrow photo‐luminescence. The structure, thermal stability, refractive index and dielectric properties of the polymer films were also determined.     

Protein Ligation-Assisted Reconstitution of Split HRP Fragments for Facile Production of HRP Fusion Proteins in E. coli

Horseradish peroxidase (HRP) is a pivotal biocatalyst for biosensor development and fine chemical synthesis. HRP proteins are mostly extracted and purified from the roots of horseradish because the solubility and productivity of recombinant HRP in bacteria are significantly low. In this study, we investigate the reconstitution system of split HRP fragments to improve its soluble expression levels in E. coli allowing the cost-effective production of bioactive HRPs. To promote the effective association between two HRP fragments (HRPn and HRPc), we exploit SpyTag-SpyCatcher chemistry, a versatile protein coupling method with high affinity and selectivity. Each HRP fragment was genetically fused with SpyTag and SpyCatcher, respectively, exhibiting soluble expression in the E. coli cytoplasm. The engineered split HRPs were effectively and irreversibly reconstituted into a biologically active and stable assembly that can catalyze intrinsic enzymatic reactions. Compared to the chaperone co-expression system, our approach shows that the production yield of soluble HRP is comparable, but the purity of the final product is relatively high. Therefore, our results can be applied to the high-yield production of recombinant HRP variants and other difficult-to-express proteins in bacteria without complex downstream processes.     

Horseradish peroxidase-mediated polyethylene glycol-templated polymerisation of gallic acid and pyrrole to improve the functionalisation and dyeing properties of silk fabrics

Silk fabrics treated with gallic acid/pyrrole (PGA/PPy) complexes polymerised using horseradish peroxidase have higher electrochemical activity than silk fabrics dyed with gallic acid alone. However, the degree of polymerisation decreases. As a result, the ultraviolet (UV) protection and fastness of the silk fabric were lowered. To solve this problem, we studied the degree of polymerisation of the complex and the functionality of dyed silk fabrics by applying a polyethylene glycol (PEG) template to the enzymatic polymerisation of PGA/PPy. The polymerisation mechanism of the complexes was analysed in detail using UV-visible spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and high-performance liquid chromatography electrospray ionisation mass spectrometry (HPLC-ESI-MS). Consequently, the PGA/PPy/PEG complex has a higher degree of polymerisation than the PGA/PPy prepared without PEG, indicating that the PEG template can promote the polymerisation of PGA and PPy. As a result, we found that the presence of the PEG template improved the thermal stability and UV protection function of the dyed silk fabric, but did not impair the electrochemical activity of silk fabric. As a result of analysing the colour depth, it exhibited a higher K/S value compared to the dyed silk fabric in the absence of PEG. Additionally, its colour fastness was improved.