IN VITRO ANTIOXIDANT AND ANTICANCER ACTIVITIES OF EXTRACTS FROM A FERMENTED FOOD

Solvent extracts were prepared from Manda Enzyme®, one of the fermented health foods, and their activities of radical scavenging and cancer cell growth inhibition were evaluated. Manda Enzyme® was extracted with 55% ethanol, and then fractionated into n‐hexane, chloroform, ethyl acetate, methanol‐soluble and methanol‐insoluble fractions. The antioxidant activities were in the order chloroform > ethyl acetate > other fractions and of each fraction were positively related to the amount of total phenolics and the intensity of brown color. The cancer cell growth inhibitory activities were in the order n‐hexane > chloroform > other fractions. Proliferation of HRT‐18, HCT‐48 and HepG2 human cancer cells was inhibited by the treatment of the n‐hexane fraction of Manda Enzyme® at a concentration of 400 μg/mL to the extent of 75, 89 and 90%, respectively. From these results, it is considered that Manda Enzyme® has chemically different ingredients showing strong antioxidant and anticancer activity in vitro.     

CAPILLARY EXTRUSION VISCOMETER FOR THE VISCOSITY MEASUREMENT OF FISH PROTEIN PASTE

To overcome various limitations of conventional viscometers in measuring salted or unsalted surimi paste, a capillary extrusion viscometer was developed. The viscosity of surimi paste was measured as a function of moisture content (MC) (75–80%), salt content (2–4%) and liquid egg white (LEW) content (2–4%). As moisture, salt and LEW contents increased, viscosity gradually decreased. The viscosity values, as affected by MCs, showed a highly negative relationship with fracture properties of surimi gel, especially shear stress from the torsion test, indicating that MC is linearly correlated to the strength of gels at fracture. This easy and quick viscosity measurement can effectively facilitate the production control of comminuted muscle foods, including surimi paste.

PRACTICAL APPLICATIONS

There had been a difficulty to measure the exact viscosity of comminuted muscle food pastes when conventional viscometers were used. This was due to the non-linearity between dilution rates and viscosity of muscle paste, or limited range of shear rate during viscosity measurement. New developed small capillary extrusion viscometer can measure a wide range of comminuted muscle paste viscosity. When using this capillary viscometer, flow behavior of non-Newtonian surimi paste and other comminuted muscle paste can be well defined.     

Mechanical Properties and Chemical Composition of Peanuts as Affected by Harvest Date and Maturity

Harvest date and maturity (by the Hull Scrape method) were compared to mechanical properties and chemical composition of peanuts. In general, later-harvested or mature peanuts exhibited higher cutting and shear-compression forces, shear-compression energy and slope of force-deformation curve than earlier-harvested or immature peanuts. Mesocarp color of peanuts could be used as an index to group peanuts with similar shear-compression energy (sensory crunchiness). Harvest date did not affect dry basis chemical composition except carbohydrates content decreased slightly as digging was delayed. Oil content increased and carbohydrates decreased as peanuts matured. Total unsaturated fatty acids content increased with maturity.     

NONENZYMATIC BROWNING IN DRIED RED PEPPER PRODUCTS

The nonenzymatic browning of dried red peppers was studied under various water activities, storage temperatures, and packaging atmospheres. Whole pepper and pepper powders-coarse and fine, with and without seeds-were compared. The browning can be described by the zero order reaction, and the rate constant is strongly affected by water activity and temperature. Flushing the package with nitrogen did not have a significant effect on the browning rate. For minimum browning, the peppers should be stored at water activities below 0.3 and in the form of whole pods or coarse powder with seeds.     

CLONING, EXPRESSION AND CHARACTERIZATION OF NOVEL LECTIN FROM ORYZA SATIVA

A lectin gene homolog of Oryza sativa was successfully cloned and expressed in Escherichia coli. The deduced amino acid sequence of the protein product showed a significant similarity with known chitin‐binding lectins. Most of the recombinant lectin was found in an insoluble aggregated form as inclusion bodies and only a small part was in the culture medium in a soluble active form. Functional recombinant lectin was recovered from the inclusion bodies by solubilization with 8 M urea in Tris/HCl buffer, pH 7.0 and renaturation by 10‐fold dilution in the same buffer. The recombinant lectin with His‐tag was simply purified to homogeneity by the process of affinity chromatography and was obtained with a yield of 6–8 mg/L culture. The recombinant lectin was a homo‐dimer composed of 22 kDa. The hemagglutination activity of the recombinant lectin was optimal at pH 4.0–7.0 and it was very sensitive to inhibition by N‐acetylneuraminic acid and thyroglobulin.     

纳米SiO2与尿素修饰大豆7S与11S球蛋白胶黏特性的研究

以大豆7S和11S球蛋白为研究对象,采用纳米二氧化硅(SiO2)对其进行分子修饰,添加量分别为蛋白基料的0.5%、1.0%、1.5%,然后用1、3、5 mol/L尿素控制变性相结合的方法来提高7S与11S球蛋白在3种木材(水曲柳、樱桃木、松木)上的胶黏强度。结果表明,经纳米SiO2修饰后,大豆7S和11S球蛋白的胶黏强度明显增大,最佳添加量为1%;当浓度为1 mol/L的尿素与1%的纳米SiO2共同修饰7S和11S球蛋白后,其胶黏强度最大。同时采用差示扫描量热仪测定了大豆球蛋白修饰前后的焓变,并探讨了胶黏作用增强的可能机理。     

Finite Element Analysis of Ceramic Coatings under Spherical Indentation with Metallic Interlayer: Part Ⅰ Uncracked Coatings

Spherical indentation of ceramic coatings with metallic interlayer was performed by means of axisymmetric finite element analysis (FEA). Two typical ceramic coatings with relatively high and low elastic modulus deposited on aluminum alloy and carbon steel were considered. Various combinations of indenter radius-coating thickness ratios and interlayer thickness-coating thickness ratios were used in the modeling. The effects of the interlayer, the coating and the substrate on the indentation behavior, such as the radial stress distribution along the coating surface as well as the coating interface, and the plastic deformation zone evolution in the substrate were investigated in connection with the above mentioned ratios. The coating cracking dominant modes were also discussed within the context of the peak tensile stresses on the coating surface and on the coating interface.     

OVER-EXPRESSION OF PROLINE-LINKED ANTIOXIDANT PATHWAY AND MODULATION OF PHENOLIC METABOLITES IN LONG LIFE SPAN CLONAL LINE OF ORIGANUM VULGARE IN RESPONSE TO ULTRAVIOLET RADIATION

Tissue culture-generated shoot-based clonal lines of oregano that have a short and long life span during in vitro culture were investigated to determine the role of proline-linked pentose phosphate pathway in modulating phenolic response following ultraviolet (UV) exposure. This novel reductant cycling pathway for energy and oxidative pentose phosphate pathway (PPP) is more efficient in long life span O-17 clonal line in response to UV and this supported antioxidant response. UV treatment stimulated rosmarinic acid and associated antioxidant enzyme response in O-17 clonal line compared with short life span O-3 clonal line. Additionally, O-17 clonal line had higher glucose-6-phosphate dehydrogenase and guaicol peroxidase activity in response to UV exposure compared with O-3 clonal line, indicating stimulation of anabolic pathway supporting PPP during UV treatment. The stimulation of proline dehydrogenase (PDH) activity in O-17 clonal line in response to UV indicated a switch to PDH-linked energy pathway via proline oxidation.

PRACTICAL APPLICATIONS

This oregano clonal model of ultraviolet (UV)-induced oxidative stress management has implications for designing dietary phytochemicals to manage oxidation-linked disease in humans. Further, the correlation between UV-linked inducibility of phenolic-linked antioxidant enzyme response through proline-linked pentose phosphate pathway and life span of in vitro shoot cultures of specific oregano clonal lines can be a good model for aging studies. The metabolic response link to aging and protective phytochemicals can be investigated in oregano tissue cultures, and phenolic extracts from various responding clonal lines could be explored in other eukaryotic aging models.