Inhyu Bae

Improvement in post-thaw viability of in vitro-produced bovine blastocysts vitrified by glass micropipette (GMP)

The purpose of this study was to investigate the use of a glass micropipette (GMP) as a vessel for vitrification of in vitro-produced (IVP) bovine blastocysts and to compare the results with post-thaw survival rate of bovine blastocysts frozen in GMP with those frozen in open pulled straw (OPS) that have been previously investigated. The GMP vessel permitted higher freezing and warming rates than the OPS due to the higher heat conductivity of the glass and the lower mass of the solution that contained the embryos. Groups of three bovine IVP blastocysts were sequentially placed into vitrification solution before being loaded into either the OPS or GMP vessels and they immersed into LN(2) within 20-25 s. Post-thaw blastocysts were serially washed in 0.25 and 0.15 M sucrose in a holding medium (HM: D-PBS supplemented with 5% FCS) and then in TCM-199 for 5 min in both cases. They was then cultured in TCM 199 supplemented with 10% FCS for 24 or 48 h. The rate of blastocyst re-expansion was significantly different between OPS (79.6%) and GMP (90.4%) methods. Neither was the hatching rate significantly different among OPS (51.8%), GMP (57.1%) methods and non-vitrified group (67.3%). Only the rate of post-thaw re-expanding of blastocysts loaded in narrow column was significantly higher than that of the wide column (83.3% versus 56.7%) (P < 0.05), although the GMP straw was loaded with three blastocysts per vessel. These results indicated that the GMP vessels provided high survival rates of bovine IVP blastocysts. The location of the embryos loaded into a narrow or wide portion was considered to be a limiting factor to the viability of bovine IVP embryos.

Pretreatment with Lycopene Attenuates Oxidative Stress-Induced Apoptosis in Human Mesenchymal Stem Cells

Human mesenchymal stem cells (MSCs) have been used in cell-based therapy to promote revascularization after peripheral or myocardial ischemia. High levels of reactive oxygen species (ROS) are involved in the senescence and apoptosis of MSCs, causing defective neovascularization. Here, we examined the effect of the natural antioxidant lycopene on oxidative stress-induced apoptosis in MSCs. Although H2O2 (200 μM) increased intracellular ROS levels in human MSCs, lycopene (10 μM) pretreatment suppressed H2O2-induced ROS generation and increased survival. H2O2-induced ROS increased the levels of phosphorylated p38 mitogen activated protein kinase (MAPK), Jun-N-terminal kinase (JNK), ataxia telangiectasia mutated (ATM), and p53, which were inhibited by lycopene pretreatment. Furthermore, lycopene pretreatment decreased the expression of cleaved poly (ADP ribose) polymerase-1 (PARP-1) and caspase-3 and increased the expression of B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein (Bax), which were induced by H2O2 treatment. Moreover, lycopene significantly increased manganese superoxide dismutase (MnSOD) expression and decreased cellular ROS levels via the PI3K-Akt pathway. Our findings show that lycopene pretreatment prevents ischemic injury by suppressing apoptosis-associated signal pathway and enhancing anti-oxidant protein, suggesting that lycopene could be developed as a beneficial broad-spectrum agent for the successful MSC transplantation in ischemic diseases.

A Study on the Yogurt Manufacture Suitability and Antimicrobial Activity of Lactobacillus plantarum LHB55 Isolated from Kimchi

The aim of this study was to develop a new starter for fermented milk. The approach started with 103 acid-producing isolates from Kimchi, a type of spiced, fermented cabbage and then PCR screening was used to identify 72 Lactobacillus strains. The ability to inhibit the growth of food-borne human pathogens (Escherichia coli, Salmonella enteritidis, Staphylococcus aureus) of these strains were measured, using the paper disk method. Among them, one bacterium (LHB55) that showed a strong antibacterial activity against food-borne human pathogens was identified and further characterized, using 16S rDNA sequencing and API 50CHL system. Because this isolate was identified as L. plantarum, it was named as L. plantarum LHB55. The yogurt produced using commercial LAB with L. plantarum LHB55 did not display properties that are microbially or physico-chemically different from the control group, which suggests that L. plantarum LHB55 can be used as a useful starter for yogurt containing high antibacterial activity. We think that identifying effective starter strains enabling further development of fermented milk that can deliver better health benefits such as antimicrobial properties is of high significance, and thus our effort in this type of approach will continue. (Key words : Kimchi, Lactic acid bacteria, Lactobacillus plantarum, Antibacterial activity, Yogurt)

Inhibitory Effect of Cinnamon Essential Oils on Selected Cheese-contaminating Fungi (Penicillium spp.) during the Cheese-ripening Process

The antifungal effects of essential oils (EOs) on cultures of the known cheese fungal contaminants Penicillium spp. were evaluated. Cinnamon leaf and bark EOs were the most effective among 8 EOs tested. The main components of both cinnamon EOs were eugenol, cinnamaldehyde, and linalool. Both inhibited growth of Penicillium spp. at a concentration of 10% v/v (2,000 ppm/mm2) on a lawn cell plate. When tested using 3 commercially available cheese starters, cinnamon EOs showed no effect against the FD-DVS ABT-5 cheese starter. However, growth of lactobacilli was inhibited in the presence of ≥10% (v/v) of leaf and bark EOs for the KAZU 1 starter, and ≥5% (v/v) for the FD-DVS FLORA-DANICA starter. A concentration of 4,000 ppm/mm2 of cinnamon EOs completely inhibited growth of the Penicillium spp. that naturally contaminates the surface of Appenzeller cheese.

Characteristics of Gouda cheese supplemented with fruit liquors

This study was conducted in order to evaluate the quality characteristics of Gouda cheeses supplemented with fruit liquor (Prunusmume or Cornus officinalis). Fruit liquor was supplemented to Gouda cheeses during preparation. Changes in chemical composition, lactic acid bacterial population, pH, water-soluble nitrogen, sensory characteristics, and proteolysis were monitored in the prepared ripened cheese. The electrophoresis patterns of cheese proteins, fruit liquor functional component concentrations, and the flavonoid content of the cheeses were also determined. The addition of fruit liquor did not affect (p> 0.05) the appearance or sensory characteristics of the cheeses. Higher amounts of crude ash, mineral, and flavonoids (p< 0.05) were observed in the liquor supplemented cheese than in the control cheese. Findings from this study suggest that wine supplemented Gouda could provide additional nutrients while maintaining flavor and quality.

Physicochemical and Sensory Properties of Red Ginseng Extracts or Red Ginseng Hydrolyzates-added Asiago Cheese during Ripening

This study was carried out to investigate physicochemical properties of different concentrations (0.1%, 0.3%, and 0.5%) of red ginseng hydrolyzates (RGH)- or red ginseng extract (RGE)-added Asiago cheeses (AC) during ripening at 14°C for 4 months. The moisture content significantly increased with increasing concentrations of both RGH- and RGE- added AC (p<0.05). While RGHAC and RGEAC were more yellow and darker with increasing concentrations than that of control (p<0.05), the color was not influenced from the hydrolysis. In texture analysis, hardness, cohesiveness, and chewiness of RGHAC and RGEAC significantly decreased compared to the control during the ripening (p<0.05). In sensory analysis, bitterness and ginseng flavor and taste scores increased significantly with increasing the concentrations of RGH and RGE during ripening (p<0.05). In conclusion, the addition of RGH and RGE into cheese slightly influenced the properties of Asiago cheese, and similarities were observed between RGHAC and RGEAC. Thus, the lower concentrations (0.1% to 0.3%) of RGH and RGE added to AC were preferred for color, texture, and sensory during the ripening, therefore, these cheeses would be worth developing commercially.

Quality Properties of Gouda Cheese Added with Fish Surimi

The effects of adding fish surimi to Gouda cheeses on quality characteristics during ripening were investigated. Cheese samples were prepared with 1.0% fish surimi, changes in chemical composition, lactic acid bacterial population, pH, non casein nitrogen, non protein nitrogen, water-soluble nitrogen, were monitored every 3 weeks during ripening. The electrophoresis patterns of cheese protein and the consumers sensory evaluation test of Gouda cheese added with fish surimi also were analyzed. Slightly higher amounts of moisture, crude ash, crude protein, and crude fat were observed in the cheese supplemented with the fish surimi compared to the control cheese. The results suggested that the Gouda cheese prepared with fish surimi did not affect appearances or consumers sensory characteristics of the cheeses. (Key words : Gouda cheese, Fish surimi, Cheese ripening, Consumers sensory evaluation)

Quality Characteristics, Changes in Physiochemical Properties and Functional Properties of Camembert Cheese Containing Red Ginseng Powder

Effects of quality, physicochemical properties and antioxidants in Camembert cheese added with red ginseng powder (RGP) were investigated. Cheese samples were prepared with 0.05%, 0.10%, 0.15% and 0.20% RGP. and then monitored during ripening at 14°C for 28 d. The pH of the RGP amended treatment groups increased during the ripening period relative to the control (p<0.05). Moreover, the 1,2-Diphenyl-1-picrylhydrazyle (DPPH) was highest in the 0.15% RGP group from 21 d to 28 d. ABTS+ radical scavenging activity was increased just like DPPH as the ripening period passed, 0.10% treatment was highest at from 7 d to 21 d. 0.15% RGP was contents of ginsenosides : 10,999.7 ppm. The Free fatty acids (FFA), controls with 0.15% treatment, while the total fat (TF) and monounsaturated fat (MuSF) were higher in the control than the 0.15% RGP group (p<0.05). The total free amino acid (FAA) was increased in the control, and 0.15% RGP, and control was highest at then 0.15% RGP. The samples had average contents of fat and protein were 29% and 18-20% respectively. Additionally, the L* value decreased, while the a* and b* values increased as the amount of RGP added increased. Sensory evaluation revealed that texture and total acceptability were higher in the control group at 12 d. Although the addition of RGP did not exert a better effect on the ripening of the camembert cheese, but the ripening grade was similar to that of the common camembert cheese, and the additional function of the cheese was reinforced. Functional cheese could be developed.