Yun-Kyung Lee

Effects of selenylation modification on structural and antioxidant properties of pectic polysaccharides extracted from Ulmus pumila L.

The present study was carried out to determine the effects of selenylation on structural and antioxidant activities of pectic polysaccharides extracted from Ulmus pumila L. (PPU). Selenylation of PPU (Se-PPU) was synthesized by different concentrations of sodium selenites (0.2, 0.4, 0.6, 0.8, and 1.0g). Structural properties of Se-PPUs were characterized using ICP-OES, HPGPC, FE-SEM, XRD, FT-IR and NMR. After selenylation, the selenium contents and the molecular weights of PPU increased. In FT-IR analysis, a new intensive absorption band at around 667cm-1 was observed in Se-PPU. From 13C NMR spectra, the new peak at 62.41ppm was found in Se-PPU probably due to the substitution of selenyl groups. In vitro antioxidant activities of all samples were evaluated by reducing power, nitrite scavenging, superoxide dismutase like scavenging activities, hydroxyl radical scavenging activities, and DPPH radical scavenging activities. The antioxidant activities of Se-PPUs were significantly higher than those of PPU. In conclusion, Se-PPU exhibited the potential possibility of the use as an antioxidant in foods and pharmaceuticals. Furthermore, the expanded use of Se-PPU produced from Ulmus sources may be taken in account for better health improvement.

The characterization, selenylation and anti-inflammatory activity of pectic polysaccharides extracted from Ulmus pumila L.

The specific objective of this study was to investigate characterization, selenylation, and anti-inflammatory activities of pectic polysaccharides extracted from Ulmus pumila L. (PPU). Four different monosaccharides were found in PPU, including galacturonic acid, galactose, rhamnose, and glucose. FT-IR spectra indicated that pectic polysaccharides were successfully extracted from Ulmus pumila L., and were probably low methoxyl pectin. GC-MS and NMR analysis of PPU suggested the major monosaccharide of PPU was α-1,4-linked galacturonic acid with α-1,2-linked rhamnose as the backbone and glucose or galactose residues as branches at C-3 and C-4 positions of rhamnose. Selenylation of PPU was synthesized by 0.2 and 0.4% of sodium selenites. Selenized-PPU (Se-PPU) inhibited LPS-induced nitric oxide production in RAW 264.7 cells, and increasing selenium content enhanced anti-inflammatory properties of PPU. Therefore, Se-PPU can be used as a potential source of bioactive compounds for nutraceuticals and pharmaceutical applications.

The preventive effects of nanopowdered red ginseng on collagen-induced arthritic mice

Abstract This study was carried out to investigate the efficiency of red ginseng nanopowder in preventing collagen-induced arthritis (CIA) in mice. The mice were divided into five groups: normal group (no immunisation), control (CIA), powdered red ginseng (PRG), nanopowdered red ginseng (NRG) and methotrexate (MTX). Administering MTX, PRG and NRG to arthritic mice significantly decreased spleen indexes, clinical and histological scores compared to control group. Serum analysis of NRG and MTX groups showed a reduction in the cytokines such as the levels of tumour necrosis factor alpha (TNF-α), interleukin 6 (IL-6) and interleukin 1β (IL-1β) in comparison to PRG group. The levels of immunoglobulin M (IgM) and immunoglobulin G1 (IgG1) in the NRG group were significantly lower than those of the PRG group. In summary, the present study indicated that NRG can be effective in preventing type II collagen-induced rheumatoid arthritis in mice.

Red ginseng extract capsule fabricated using W/O/W emulsion techniques

ABSTRACT The objective of the present study was to investigate the physicochemical characteristics and storage stability of water-in-oil-in-water (W/O/W) emulsions and spray-dried red ginseng extract capsules (RGEC) prepared using different secondary coating materials such as maltodextrin (MD), whey protein concentrate (WPC), or arabic gum (AG). The particle sizes of W/O/W emulsions and spray-dried RGEC coated with MD were considerably lower than those of W/O/W emulsions and spray-dried RGEC coated with WPC or AG. The zeta-potential value (−36 mV) of spray-dried RGEC coated with MD was significantly higher than that of spray-dried RGEC coated with WPC or AG (p < 0.05), indicating that spray-dried RGEC coated with MD were much more stable than spray-dried RGEC coated with WPC and AG. In the storage stability study, it was found that the refrigerator temperature (4°C) was preferred for storing spray-dried samples for a long time. Based on these results, it was confirmed that MD could be the most efficient coating material for W/O/W emulsions and nano-sized spray-dried RGEC.

Structural and rheological properties of pectic polysaccharide extracted from Ulmus davidiana esterified by succinic acid

The present study was carried out to investigate the physicochemical and structural properties of pectic polysaccharide extracted from Ulmus davidiana (UDP) and to determine the physicochemical, structural, and rheological properties of esterified UDP with succinic acid (ES-UDP). The results indicated that UDP had high amounts of galacturonic acids and various neutral sugars, such as galactose, rhamnose, and glucose. UDP was identified as a low methoxyl pectin, consisting of 1,4-linked α-d-GalpA (the main backbone chain), supported by the results of Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction, and 1D Nuclear magnetic resonance (NMR) spectroscopy. In the FT-IR and XRD, no difference was detected between UPD and ES-UDPs. However, 1H and 13C NMR spectra revealed that the new ester bonds were formed between a hydroxyl group of UDP and a carboxyl group of succinic acid during esterification. In the steady shear rheological analysis, the consistency index (K) of ES-UDP was significantly higher than that of UDP and increased significantly with increasing concentration of succinic acid. In the dynamic rheological analysis, the tan δ values of all ES-UDP solutions were significantly lower than those of the UDP solution.

Highly bioavailable nanocalcium from oyster shell for preventing osteoporosis in rats

Abstract Oyster shell is one of the foremost natural sources of calcium and is used as an alternative treatment for osteoporosis. In this study, we demonstrated that zinc-activated nanopowdered oyster shell (Zn-NPOS) effectively reduced bone loss compared with powdered oyster shell (POS) in an ovariectomized rat (OVX) model. As a result of nanosizing, the solubility and bioavailability of the oyster shell were greatly improved, and its effectiveness was further enhanced by zinc activation. Bone analysis indicated greater recovery from ovariectomy-induced bone loss following Zn-NPOS treatment. Moreover, Zn-NPOS treatment resulted in higher bone strength and superior trabecular architecture compared with NPOS and POS treatments. Furthermore, Zn-NPOS showed greater efficiency in increasing bone formation and reducing bone resorption markers. Therefore, nanosizing with zinc activation could be a viable strategy for improving the efficiency of oyster shells used for osteoporosis prevention.

Rheological, pasting, and structural properties of potato starch by cross-linking

ABSTRACT The present study determined the effects of cross-linking with sodium trimetaphosphate (STMP)/sodium tripolyphosphate (STPP) on the structural, rheaological, and pasting properties of potato starch. Starches cross-linked by STMP/STPP at 0.0125%, 0.025%, 0.05%, 0.5%, 5%, and 10% were designated as the cross-linking of potato starch (CLPS)-0.0125, CLPS-0.025, CLPS-0.05, CLPS-0.5, CLPS-5, and CLPS-10, respectively. Scanning electron microscope revealed that STMP/STPP treatment resulted in some changes in the surface of the native potato starch (NPS) granules. An analysis with a light microscope showed that NPS granules were completely ruptured and had disappeared but that the granules of CLPS-0.0125, CLPS-0.025, and CLPS-0.05 were scarcely ruptured after heating at 95°C for 30 min. The 31P nuclear magnetic resonance spectra of CLPS-5 and CLPS-10 showed new peaks of monostarch diphosphate, cyclic-monostarch monophosphate, and distarch monophosphate. Pastes of CLPS-0.0125, CLPS-0.025, and CLPS-0.05 exhibited significantly higher shear-thinning fluid characteristics than NPS. Steady and dynamic shear analysis showed that, compared to NPS, CLPS pastes (0.5, 5, and 10) had significantly greater apparent viscosity (ηa,100), consistency index (K), yield stress (σoc), dynamic moduli (G′, G″), and complex viscosity (η*). These results indicate that cross-linking with STMP/STPP can be used to improve the rheaological and pasting properties of potato starch for desired food applications.

Structure and digestibility properties of resistant rice starch cross-linked with citric acid

ABSTRACT The objective of this present study was to determine the structural, physicochemical, and in-vitro digestibility properties of cross-linked rice starch with citric acid (CARS). Native rice starch (NRS) was cross-linked with different concentrations of citric acid (0, 1, 10, and 30%, w/w) of starch dry basis. The SEM results showed that cross-linking with citric acid induced changes in the morphology of starch granules. Compared with NRS, a new peak at 1734 cm−1 appeared in FT-IR spectra of CARS samples, except CARS1. In the X-ray diffraction patterns, crystalline peaks of all CARS samples became much smaller or even disappeared, as compared to that of NRS. 13C NMR spectra of CARS10 and CARS30 showed new peaks at about 45.55 ppm; in particular, an additional peak at 178.94 ppm occurred in the spectrum of CARS30. The swelling factor, light transmittance, thermal properties, and pasting properties of CARS were significantly lower than those of NRS. Furthermore, resistant starch contents of NRS were significantly increased, while the rapidly digestible starch and slowly digestible starch contents of NRS were significantly decreased after cross-linking with citric acid. Therefore, cross-linked rice starch with citric acid showed potential for application as a dietary fibre source in the food industry.