• Korean journal of applied entomology
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• v.49 no.4
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• pp.409-416
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• 2010

An entomopathogenic bacterium, Photorhabdus temperata ssp. temperata (Ptt), suppresses insect immune responses and facilitates its symbiotic nematode development in target insects. The immunosuppressive activity of Ptt enhances pathogenicity of various microbial pesticides including Bacillus thuringiensis (Bt). This study was performed to select a cheap and efficient bacterial culture medium for large scale culturing of the bacteria. Relatively cheap industrial bacterial culture media (MY and M2) were compared to two research media, Luria-Bertani (LB) and tryptic soy broth (TSB). In all tested media, a constant initial population of Ptt multiplied and reached a stationary phase at 48 h. However, more bacterial colony densities were detected in LB and TSB at the stationary phase compared to two industrial media. All bacterial culture broth gave significant synergism to Bt pathogenicity against third instars of the diamondback moth, Plutella xylostella. Production of bacterial metabolites extracted by either hexane or ethyl acetate did not show any significant difference in total mass among four culture media. Reverse phase HPLC separated the four bacterial metabolites, which were not much different in quantities among four bacterial culture broths. This study suggests that two industrial bacterial culture media can be used to economically culture Ptt in a large scale.

• Food Science and Preservation
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• v.19 no.3
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• pp.406-412
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• 2012

The purpose of this research is to develop functional food with garlics(Allium sativum var. pekinense) as a healthy food. Fermented garlic broth(FGB)s were prepared with whole bulb of garlics preserved in sugar and sugar syrup, then fermented and aged at room temperature for 36 months. Biological activities of FGBs were tested antibacterial, antioxidative, fibrinolytic activities and analyzed for polyphenol contents. The total polyphenol contents of FGBs in 12~36 month fermented broth(870~885 mg/100 mL of broth) had significantly higher than those of 1~6 months fermented broths(p<0.001). The electron donating abilities(EDAs) and SOD-like activities of 24~36 month fermented broth had significantly higher than those of 1~6 months fermented broths(p<0.05). FGBs had shown strong antibacterial activities against four kinds of pathogenic bacteria(L. monocytogenes, S. aureus, E. coli O157:H7, and Sal. typhimurium). The fibrinolytic activities of 24~36 months fermented broth had more than twice of the fibrinolytic activity of plasmin. FGBs had increasing activities in antibacterial, antioxidative and fibrinolytic activity as the progress of fermentation period. FGBs can be used as natural antioxidant to prevent oxidative damage on normal cells probably because of their antibacterial, antioxidative and fibrinolytic activities.

• Food Science and Preservation
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• v.16 no.1
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• pp.23-32
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• 2009

This study evaluated quality characteristics of spirulina (0.63, 1.25, and 2.5%, all w/w) added noodles during storage at 4C. Total bacterial counts in raw spirulina added noodles were higher than those of the control during storage, but no bacteria were detected in cooked noodles. Escherichia coli was not detected in any group. The weight loss, volume loss, and moisture absorption of spirulina added noodles were somewhat greater than control values. Moisture contents of spirulina added noodles both before and after cooking decreased as the spirulina level increased. During storage, moisture loss from spirulina added noodles was a little greater than from the control. Hunter color values for L (lightness), a (redness), and b (yellowness) decreased during storage. The spirulina added noodles had significantly greater hardness, cohesiveness, gumminess, and chewiness compared with the control. The antioxidant activity of spirulina added noodles increased with spirulina level. A sensory preference test revealed that noodles with 1.25% spirulina received the highest scores for chewiness, overall preference, and buying intention. It is suggested that spirulina could be added to noodles at a concentration of up to 1.25% to improve quality.

• Food Science and Preservation
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• v.21 no.4
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• pp.581-586
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• 2014

With the current consumer trend toward health and wellbeing, the demand for consumption of fresh cut vegetables has been increasing. As a popular vegetable with functional components, sedum (Sedum sarmentosum) is widely used in Korea as a side dish that needs no cooking. In this study, to provide a hurdle technology for postharvest sedum, the effects of combined treatment of 1% acetic acid for washing and $10kJ/m^2$ UV-C irradiation on the microbial growth and quality of sedum were examined. After the treatment, the sedum samples were stored at $10^{\circ}C$ for six days, and the results of their microbial analysis as well as their color, vitamin C content, and antioxidant activity were analyzed. The combined treatment with acetic acid and UV-C irradiation reduced the initial populations of the total aerobic bacteria and the yeast and molds in the sedum by 3.28 and 4.22 log CFU/g, respectively, compared to those in the control. The Hunter L, a, and b values of the sedum did not significantly differ across the treatments. In addition, the vitamin C content and the antioxidant activity decreased significantly during the storage, regardless of the treatment. These results suggest that the combined treatment with 1% acetic acid and $10kJ/m^2$ UV-C irradiation can be useful as a hurdle technology for retaining the microbiological safety and quality of sedum during its storage.

• Food Science and Preservation
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• v.24 no.8
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• pp.1180-1187
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• 2017

Zingiber officinale Roscoe, commonly known as ginger, has long been used as a powerful health-promoting antioxidant that supports cellular health of the human body. The objective of this study was to compare the antioxidant and antimicrobial activities of the samples with aging and fermentation. Antioxidant activities of the samples were compared using total phenol, flavonoid contents, ABTS cation radical scavenging activity and DPPH radical scavenging activity. Antimicrobial activities were also examined using the paper disc method and minimum inhibitory concentration (MIC). Acidity of the fermented ginger (FG) with lactic acid bacteria showed a significantly higher value than that of the ginger (GG). The content of 6-gingerol, a bioactive component in ginger, decreased in all fermented gingers but 6-shogaol which is also one of the main valuable ingredients showed the increased content at ginger fermented with Streptococcus thermophilus and Lactobacillus acidphilus. Flavonoid contents of the FG and GG did not show significant differences. However, ABTS cation radical scavenging activity and DPPH radical scavenging activity were 10-30% increased in the samples with fermentation (p<0.05), respectively. The samples of the disc showed an inhibitory effect on growth of gram positive Staphylococcus aureus and Listeria monocytogenes. Zinger with fermentation showed higher antioxidant and antimicrobial activities. Thus, we conclude that aging and fermentation can be a helpful process to increase the functional effects of ginger.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.2
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• pp.111-121
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• 2003

Physicochemical and sensory characteristics of turnip Donchimi prepared with Chinese(DC), Korean(DK) and European origin(DE) were analyzed during fermentation at $0^{\circ}C$. Salt concentrations of Dongchimi liquid were around 1.3% during fermentation. The pH, the total acidity, Lactobacilli number and turbidity were observed during fermentation of Dongchmi. DC was fermented the most rapidly among three based on the acidity, turbidity and lactic acid bacteria number. DC maintained higher hardness in textural properties during fermentation compared to DE, although it was evaluated lower scores of appearance in sensory test, and less Hunter color a value and anthocyanin content, compared to DK or DE. DK showed the highest in anthocyanin content, Hunter color a value, and hardness. Sensory evaluation showed that the scores of color, hardness, and overall preference of Donchimi were high in the order of DK>DC>DE. Score of overall preference of turnip Dongchimi was the highest with 6.7(10 cm line scale) in DK at the 40th day of fermentation, the optimum ripening time, but the lowest with 3.5 in DE.

• Journal of Aquaculture
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• v.21 no.1
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• pp.1-6
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• 2008

We determined the effects of dietary supplements for lactic acid bacteria(LAB) such as Lactobacillus brevis(Lb) and Lactobacillus plantarum(Lp) in juvenile rockfish Sebastes schlegeli cultured in flow-through system for 10 weeks. The experimental diets contained $10^4cfu/g,\;10^6cfu/g\;and\;10^8cfu/g$ level each LAB(Lb-4, Lb-6, Lb-8 or Lp-4, Lp-6, Lp-8), respectively. The effects of LAB supplementation was determined by various factor such as weight gain(WG), specific growth rate(SGR), feeding efficiency(FE) and blood assay. For rearing experiment, Lp-8 treatment had significantly high growth rate than control diet treatment. However, all Lb treatment had no significance effect with control diet treatment. In case of the blood assay, hematocrit(Ht) and hemoglobin(Hb) of fish were not affected by LAB supplemental levels. On the other hand, total cholesterol in plasma of Lb-8, Lp-6 and Lp-8 treatments were significantly low than the control diet treatment. We verified the influence of LAB which was originated from species specificity and amount in diet. Consequently, the dietary supplementation as $10^8cfu/g$ level of L. plantarum could be of help for growth enhancement to the juvenile rockfish.

• Food Science and Preservation
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• v.24 no.6
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• pp.827-833
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• 2017

This study was investigated the effects of various commercial sanitizers on microbial characteristics in fresh-cut iceberg lettuce during storage. For screening sanitizer, lettuce was cut and dipped in chlorine water ($0.2ml{\cdot}L^{-1}$), solution of organic acids such as ascorbic acid, citric acid, acetic acid, mixture of ascorbic acid and acetic acid (1-6%), and solutions of commercial sanitizers such as Formula 4$^{TM}$ (1,3,4%), Fresh produce wash$^{TM}$ (1,3,4%), Cleancol$^{TM}$ (1%), Chitochol$^{TM}$ (1%) and Natural Ca$^{TM}$ (0.1%) for 3 min, respectively. Washing lettuce with selected sanitizers resulted in reduction of aerobic bacteria of more than 2 log CFU/g. Initial pH of lettuce was related with the pH of sanitizers. pH ranged from 4.7 to 6.1 in Formula 4 (4%, pH 1.7) and Natural Ca (0.1%, pH 12.0), respectively. Chlorine water showed consistent and significant inhibition effect in all of microorganisms except total coliform. Over 3% of Formula 4 and Fresh produce wash were found to have high bactericidal activity among sanitizers. The sanitizers of chlorine water, Fresh produce wash, Chitochol and Natural Ca were effective in reducing yeast and mould populations. As coliform and E. coli, Formula 4 (4%) showed the highest bactericidal activity. The bactericidal effect of commercial sanitizers during storage varied with the kinds and concentrations of tested sanitizers. Although inhibition effect was not showed during storage, these results suggest that commercial sanitizers could be an alternative to chlorine for washing fresh-cut produce.

• Food Science and Preservation
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• v.23 no.7
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• pp.953-959
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• 2016

The quality characteristics and processing of rice cake (Backsulgi) with rice flour containing Lactobacillus plantarum CGKW3 by spray-drying (LP-B) were investigated. The LP-B was applied at ratios of 10, 20, and 30 (w/w), and the moisture contents and pH were 33.39%~36.70% and 5.81~5.46, respectively. The L value of LP-B increased as the rice flour decreased, while the a and b value increased as the LP-B increased. The texture profiles showed that Backsulgi prepared with LP-B mixture had higher hardness, cohesiveness, springiness and chewiness than 100% rice flour. The pH of LP-B Backsulgi (LP-B20 and LP-B30) did not differ during 6 days at room temperature. The total bacteria in Backsulgi prepared LP-B20 and LP-B30 Backsulgi was $10^4CFU/g$ after 2 days of storage at room temperature. The shelf life of Backsulgi prepared with LP-B20 and LP-B30 were extended by about 2 days when compared with the control at room temperature. Sensory evaluation showed that Backsulgi without LP-B20 had higher scores in terms of appearance, color, flavor, taste, texture, hardness and overall acceptability than Backsulgi without 100% rice flour. In conclusion, the results demonstrate that LP-B20 may prove quite useful as a Backsulgi flour with desirable properties.

• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1619-1627
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• 1999

Microbiological characteristics of gamma irradiated low salt squid Jeot-gal were examined. Following the fermentation periods, total bacterial cell, Lactobacillus spp., Staphylococcus spp., Streptococcus spp., Pseudomonas spp. and yeast cell number were counted on their selective media and some acid forming bacteria and Pseudomonas spp. were identified. As the gamma irradiation dose increased, the microbial density of early fermentation phase was reduced and the growth rate was delayed. The repression effects on microbiological growth by gamma irradiation were to be higher as salt concentration increased. Adequate conditions of salt concentration and gamma irradiation for low-salt squid Jeot-gal preparation were 10% and 10 kGy, respectively. Lactobacillus sp. 2, Micrococcus varians and Streptococcus sp. I were isolated from 5% salt containing squid Jeot-gal, and Micrococcus morrhuae was from 20% only while Lactobacillus plantarum and Lactobacillus brevis were widespread. Lactobacillus brevis, Pediococcus halophilus and Pseudomonas diminuta were sensitive and Lactobacillus plantarum, Micrococcus morrhuae and Pseudomonas sp. 3 were resistant to gamma irradiation. The diversity of microflora decreased as salt concentration decreased and gamma irradiation dose increased.