• Korean Journal of Microbiology
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• v.45 no.4
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• pp.332-338
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• 2009

A xylan-decomposing bacterium, HY-20, was isolated from the gut of a honeybee, Apis mellifera, and identified as Bacillus sp. The extracellular GH11 xylanase (XylP) gene (687-bp) of strain HY-20 encoded a protein of 228 amino acids with a deduced molecular mass of 25,522 Da and a calculated pI of 9.33. The primary structure of XylP was 97% identical to that of B. pumilus xylanase (GenBank accession no.: AY526092) that has not been characterized yet. The recombinant His-tagged enzyme (rXylP) overexpressed in Escherichia coli BL21 harboring pET-28a(+)/xylP was purified to electrophoretic homogeneity by cation exchange and gel permeation chromatographies. The purified enzyme exhibited the highest catalytic activity toward birchwood xylan at pH 6.5 and $50^{\circ}C$ and retained approximately 50% of its original activity when pre-incubated at $55^{\circ}C$ for 15 min. The recombinant enzyme was completely inactivated by $Hg^{2+}$ (1 mM) and N-bromosuccinimide (5 mM), while its activity was slightly stimulated by approximately 10% in the presence of $Mn^{2+}$ (1 mM), $Fe^{2+}$ (1 mM), and sodium azide (5 mM). rXylP was able to efficiently degrade various polymeric xylose-based substrates but PNP-sugar derivatives and glucose-based polymers were not susceptible to the enzyme.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.27-36
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• 2015

The improved analytical method with gas chromatography (GC) and GC-mass spectrometry was established to identify and quantify disaccharides and trisacchrides in honey. In this method, the analysis of trimethylsilyl (TMS), TMS-oxime and TMS-methoxime sugars takes into account the determination of a single peak of complete separation on the chromatogram. The number of possible peaks for the qualitative and quantitative determination of TMS, TMS-oxime, and TMS-methoxime sugars was 17, 22, and 25, respectively. This new analytical method allowed for the determination of diand trisaccharides in honey by TMS-oxime and TMS-methoxime derivatives. This study suggested that the improved method is more suitable and precise than the other analytical methods for the simultaneous determination of sugars in honey.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.266-271
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• 2018

The Ministry of Food and Drug Safety (MFDS) is amending its test methods for health-functional foods (dietary food supplements) to establish regulatory standards and specifications in Korea. In this regard, we continue our research on developing analytical methods for the items. Octacosanol is the major component of polycosanol and is a high-molecular-mass primary fatty alcohol, obtained from sugar cane wax. Previous researchers have shown that octacosanol can lower cholesterol and has antiaggregatory properties, cytoprotective uses, and ergogenic properties for human health. Recently, octacosanol products have been actively introduced into the domestic market because of their functional biological activity. We have developed a sensitive and selective test method for octacosanol that the TMS derivatives by means of gas-chromatographic-tandem mass spectrometry (GC-MS). The trimethylsilyl ether derivative of the target analyte showed excellent chromatographic properties. The procedure was validated in the range of $12.5{\sim}200{\mu}g/L$. Standard calibration curves presented linearity with the correlation coefficient ($r^2$) > 0.999, and the limits of detection (LOD) and limits of quantitation (LOQ) were $4.5{\mu}g/L$ and $13.8{\mu}g/L$, respectively. The high recoveries (92.5 to 108.8%) and precision (1.8 to 2.4%) obtained are in accordance with the established validation criteria. Our research can provide scientific evidence to amend the octacosanol test method for the Health-Functional Food Code.

• Food Science and Preservation
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• v.20 no.4
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• pp.573-582
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• 2013

This study was done in order to investigate the bioconversion of ginsenoside, as well as the quality characteristics of fermented ginseng, by using lactic acid bacteria. Quality characteristics such as the thin layer chromatography(TLC) pattern, ginsenosides, total phenolic content, electron donating ability, and total sugar of fermenting ginseng and red ginseng were analyzed. The ginsenoside Rg2r, Rh2s and Rh2r of the fermented ginseng and red ginseng for 65 hours at a temperature of $37^{\circ}C$ were not detected. The ginsenoside Rg1 and Re contents have decreased, while the Rh1, Rg2s, Rd, Rg3r, and Rg3s have increased due to fermentation. The ginsenoside Rg3 of the fermented red ginseng has increased and the contents were $114.83{\sim}131.68{\mu}g/mL$ (control $104.56{\mu}g/mL$). The total phenolic content and electron donating ability of the red ginseng have totally decreased after 7 days of fermentation. The total phenolic contents of the fermented ginseng and red ginseng with different lactic acid bacteria did not show any tendency as different strains. The electron donating ability of the fermented ginseng has increased; however, the electron donating ability of the red ginseng has decreased. The total sugars of the fermented ginseng and red ginseng with different lactic acid bacteria have also decreased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.3
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• pp.367-372
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• 2002

In order to utilize safflower seed effectively as a food material, it was processed at the conditions including roasting temperature/time of 170$\^{C}$/10 min to 210$\^{C}$/30 min, ethanol concentration of 0 to 100% (V/V) and enzyme hydrolysis with $\alpha$-amylase, $\beta$-amylase, amyloglucosidase and cellulase. Safflower seed extracts had the highest soluble solid content at the condition of 60% ethanol concentration, roasting at 190$\^{C}$ for 20 min and hydrolysis with amyloglucosidase. Total phenolic compounds increased with the ethanol concentration, showing the highest at the condition of 80% ethanol, roasting at 170$\^{C}$ for 30 min and hydrolysis with amyloglucosidase. High level total flavonoid was observed at the condition of 80% ethanol, roasting at 210$\^{C}$ for 30 min and hydrolysis with amyloglucosidase. Safflower seed had sucrose as major free sugar as well as xylose and arabinose as minor free sugars. Organic acids in safflower seed included oxalic, citric, magic and fumaric acid. Serotonin I (N-[2-(5-hydroxy-1H-indo-1-3-yl)ethyl]ftrulamide) and serotonin II (N-[2-(5-hydroxy-1H-indol-3yl)ethyl]-p-coumaramide) as antioxidant compounds increased with ethanol concentration, showing the highest revel at 60% ethanol. Acacetin content increased with temperature and roasting time, with a maximum of 69.47 mg% at 210$\^{C}$ for 30 min.

• Journal of Life Science
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• v.29 no.5
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• pp.545-554
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• 2019

The phytochemical compounds of Pueraria, a medicinally important leguminous plant, include various isoflavones that have weak estrogenic activity and a potential role in preventing chronic disease, cancer, osteoporosis, and postmenopausal syndrome. However, the major isoflavones are derivatives of puerarin and occur mainly as unabsorbable and biologically inactive glycosides. The bioavailability of the glucosides can be increased by hydrolysis of the sugar moiety using ${\beta}$-glucosidase. In this study, we investigated the antioxidant effects of a Pueraria extract after fermentation by Lactobacillus rhamnosus BHN-LAB 76. The L. rhamnosus BHN-LAB 76 strain was inoculated into Pueraria powder and fermented at $37^{\circ}C$ for 72 hr. The total polyphenol content of the Pueraria extract increased by about 134% and the total flavonoid content increased around 110% after fermentation with L. rhamnosus BHN-LAB 76 when compared to a non-fermented Pueraria extract. Superoxide dismutase-like activities, DPPH radical scavenging, and ABTS radical scavenging increased by approximately 213%, 190%, and 107%, respectively, in the fermented Pueraria extract compared to the non-fermented Pueraria extract. Fermentation of Pueraria extracts with L. rhamnosus BHN-LAB 76 is therefore possible and can effectively increase the antioxidant effects. These results can be applied to the development of improved foods and cosmetic materials.