Earticle

Several rheological terms were introduced to estimate the properties of cooked noodles with different starch contentusing tensile tests. Ring-shaped specimens were prepared by connecting both ends of the noodle strip before cooking. Henckystrain and rate, as well as true stress were applied in constant deformation tests. The elastic region on the curves of strain vs.stress was not clearly identified. Strain hardening in the subsequent plastic region was more prominent in low-starch noodles.Elongational viscosities at lower strain rates were used to differentiate noodles with different starch content, representing thedominant effect of protein content in the range of lower strain rates. In stress relaxation tests, the reciprocal of Peleg’s constantK1 (initial decay rate) and K2 (asymptotic level) increased and decreased respectively, with an increase in starch content. Thisindicated that addition of starch contributed to the noodles becoming viscous liquid rather than elastic solid.

Antiproliferative activity of the ethanol extract of Atractylodes japonica rhizomes (AJEX) was investigated usingmethyl thiazolyl tetrazolium (MTT) assays with various cancer cell lines (HL-60, MCF-7, SK-Br-3, MDA-MB-453, HepG2,Hep3B, PC-3, LNCaP, MKN 28, MKN 45, and HT-29 cells). Gastric carcinoma cell lines were the most responsive in termsof cell proliferation. The IC50 of MKN 28 and MKN 45 cells were 35.98 and 27.57µg/mL, respectively. Moreover, gastriccarcinoma cells exposed to AJEX underwent apoptosis, as determined by Annexin V binding assay. Compared to respectivecontrol level, exposure to the AJEX at each IC50 concentration resulted in a remarkable increase in the shift of cellpopulations. Present results suggest that AJEX possess potential anticancer properties.

Cross contamination of foodborne virus via food utensils can be an important route of virus propagation.Bacteriophage MS2 was used as a surrogate for norovirus. The viability loss of bacteriophage MS2 attached to 4 kinds ofmetal surfaces was investigated at different temperatures and relative humidities (RH). The rate of viability loss was higher at22oC than at 10oC and was higher at 75% RH than at 40% RH. The viability loss of the virus attached to copper or bronzesurface was faster than on stainless steel or tin surface. Also the beef juice applied with the virus inoculum on the metalsurfaces lowered the rate of viability loss. Although bronze was not as effective as copper in resulting the viability loss, it hasbeen extensively used as a traditional Korean kitchen utensil and could be used more widely to decrease the viral poisoning atfood processing environment and hospitals.

The aim of this research was to study the structural and rheological properties of gels formed by ferulated maizebran arabinoxylans (MBAX) at different concentrations. MBAX was cross-linked by a laccase leading to the formation ofdimers and trimers of ferulic acid (di-FA, tri-FA) as covalent cross-link. An increase in MBAX gels elasticity (from 11 to 20 Pa)as well as lower mesh size (from 80 to 48nm) were obtained by augmenting the MBAX concentration from 2.5 to 3.5%(w/v),respectively, but no increase in di-FA and tri-FA content was obtained (0.03 and 0.014µg/mg MBAX, respectively).

A fermenting microorganism involved in formation of ortho-dihydroxyisoflavones (ODIs) during aging ofdoenjang (Korean fermented soybean paste) has been investigated. Microorganisms in ODI-containing doenjang were isolatedby cultivating on yeast mold (YM) agar medium containing 0-7% NaCl. ODI formation of the isolated strains was examinedby gas chromatography/mass spectrometry (GC/MS) analysis after cultivation in modified YM broth or soybean extractmedium. An ODI-producing microbe was identified as Bacillus subtilis HS-1 based on 16S rRNA gene sequence analysis.The strain has produced 8-hydroxydaidzein as a major product during growth in the modified YM broth or soybean extractmedium. Therefore, it was concluded that one of the microorganisms involved in the formation of ODIs in doenjang was B.subtilis HS-1.

In this study we analyzed the dynamic changes in microbiota composition during kochujang fermentation at 30oC.During fermentation, the viable cell counts slowly increased and reached 3.2×107 for aerobic bacteria, 8.3×103 for yeast, and1.4×103 CFU/mL for fungi after 60 days. Bacilli were found to be the most dominant microorganisms throughout thefermentation process. Using the culture dependent method Bacillus subtilis, Bacillus licheniformis, and Bacillusamyloquefaciens were found to be the main species during the early stages of fermentation; however, Bacillus pumilus andBacillus stearothermophilus became the most dominant species during the late stage of fermentation. In contrast, when thepolymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) method was used Bacillus ehimensis wasfound to be the dominant species during the early stage of fermentation and Bacillus megaterium, B. pumilus, B. subtilis, andB. licheniformis were dominant in the ate stages. These results indicate various other Bacillus species rather than just B.subtilis and B. licheniformis might be involved in the fermentation of kochujang.

Aflatoxins are secondary metabolites produced by the aflatoxigenic fungi in suitable conditions. Saffron, Crocussativus, is the most expensive spice in the world. Saffron is normally contaminated with soil and hand microflora duringharvest and post-harvest operations. In this study, rapid assessment of aflatoxigenic fungi in saffron was accomplished usingpolymerase chain reaction. In total, 37 market samples were assayed in order to isolate aflatoxin-producing fungi. The 18.9%of the total samples were contaminated with aflatoxigenic fungi. Our results also show that most of the isolated fungi weresaprophytes which are normally originated from soil during harvest and postharvest process.

A commercial propolis was investigated in terms of its antioxidant, antimicrobial, and antiproliferative activities.The contents of total phenol and flavonoid of propolis were 8.3 and 6.6 mg, respectively. The reducing power of the propolisincreased with concentration increasing. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was shown at82.70% in 1,000µg/mL of the propolis. 2,2'-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavengingeffect of antioxidant activity on the propolis was 35.64 g/sample. The propolis showed high antimicrobial activity againstBacillus cereus at all concentration of propolis. All of the cancer cell lines have 53-73% as effective growth inhibition. Theseresults showed that the commercial propolis has potential antioxidant, antimicrobial, and cancer cell proliferative inhibitionactivities thus, propolis can be applied to the functional food, pharmaceutical, and cosmetic industry.

Our previous study showed that isoflavone profile of soybean undergoes a significant change duringcheonggukjang preparation. In particular, the content of metabolite(s) with similar retention time to glycitein under the highperformance liquid chromatography (HPLC) condition was significantly increased while the levels of genistein and itsderivatives were notably lowered. Therefore, we hypothesized that genistein and its derivatives might be converted togenistein glucosides with similar elution time to glycitein. Our current data suggest that genistein and its derivatives areextensively metabolized into various compounds including genistein glycosides, but not glycitein or its derivatives, byBacillus species isolated from traditional cheonggukjang. Some of daidzein was also converted into a derivative with shorterretention time by Bacillus amyloliquefaciens 51 and 86-1 but not by Bacillus subtilis 3-5 and 3-17. As metabolism of soyisoflavones, major health-promoting components in soy products, is widely variable depending upon Bacillus species, it isessential to select microorganism that minimizes the breakdown or modification of soy isoflavones in the process of fermentedsoy product manufacture.

This study was conducted to investigate the antioxidant activity of the extracts of lotus (Nelumbo nuciferaGaertner). The total phenolic contents in leaf, stem, and root were 165, 74, and 30 tannic acid equivalent mg/g of dried extractor fraction respectively. The butanol and ethylacetate fractions of lotus parts showed higher 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging activity than other fractions. 2,2'-Azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cationradical scavenging activity also showed the similar result as the DPPH radical scavenging activity. The antioxidative capacityof the ethylacetate fraction was the highest among fractions and its fraction showed higher contents of total polyphenol.