• Journal of Applied Biological Chemistry
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• v.58 no.2
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• pp.145-151
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• 2015

Corn fiber protein (CFP) was extracted from corn wet-milling by-product, corn fiber. CFP films containing various plasticizers and cross-linking agents were prepared and their mechanical properties were determined. Among the plasticizers and cross-linking agents used in this study, the CFP film containing 2 g fructose and 0.03% cinnamaldehyde had the most appropriate physical property. In addition, the CFP films containing green tea extract (GTE) were prepared by incorporating different amounts (0, 0.5, 1.0, 1.5%) of GTE into the film-forming solution. Tensile strength, film solubility, and opacity of the CFP films increased with the addition of GTE, whereas elongation and water vapor permeability of the CFP/GTE films decreased compared to those of the control. The antioxidant activity of the CFP/GTE film was determined in terms of 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity. As a result, antioxidant activity of the films increased with increasing GTE concentration. Furthermore, antimicrobial activity against Escherichia coli O157:H7, Listeria monocytogenes, and Staphylococcus aureus increased with increasing GTE concentration. These results indicate that the incorporation of GTE could enhance antioxidant and antimicrobial activities of the CFP films.

• Food Science and Preservation
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• v.17 no.2
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• pp.196-201
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• 2010

Gelatin films containing grapefruit seed extract (GSE) were prepared by incorporating different amounts (0, 0.6, and 1.0%, w/v) of GSE into film-forming solutions. Film elongation was improved by the addition of GSE, but film tensile strength decreased to 31.96 MPa for film containing 1.0% GSE, compared with 46.39 MPa for the control. Incorporation of 1.0% GSE inhibited the growth of pathogenic bacteria such as Escherichia coli O157:H7 and Listeria monocytogenes. Packaging of strawberries with a gelatin film containing 1.0% GSE decreased the levels of total aerobic bacteria and yeast/molds after 12 days of storage by 1.60 and 1.43 log CFU/g, respectively, compared with control values. Sensory evaluation results indicated that packaging of strawberries with GSE-gelatin film resulted in better sensory scores than those of the control. These results indicate that strawberries can be packaged using gelatin film containing GSE, to extend shelf-life.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.249-254
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• 2013

As part of a study on insects as food, the nutritional and harmful components in the mealworm (Tenebrio molitor) were analyzed. In addition, due to a recent introduction of live Chinese mealworms in the Korean market, components between Korean and Chinese mealworms were compared. Analysis of general composition (moisture, crude protein, crude fat, crude ash, crude fiber, and carbohydrates) showed that crude protein (50.32~52.79%) was abundant in both Korean and Chinese mealworm powders, with the protein content in the Chinese mealworm powder higher than that in the Korean mealworm powder by 2.67%. The amino acid compositions were similar, but the fatty acid compositions differed in the Korean and Chinese mealworm powders. The unsaturated fatty acid contents were 76.80~80.55% of the total fatty acid content in the mealworms. The linoleic acid contents in the Korean and Chinese mealworms were $20.8{\pm}1.1%$ and $34.69{\pm}1.9%$; the linolenic acid contents were 0.47% and 1.31%; and the oleic acid contents were $51.40{\pm}0.9%$ and $40.20{\pm}1.5%$, respectively. With respect to harmful components, such as heavy metals and bacteria that cause food poisoning, bacteria such as Escherichia coli O157:H7 and Salmonella spp. were not detected in both Korean and Chinese mealworms, and the mercury content was below the standard values for common foods (Korea, 0.03 mg/kg; China, 0.08 mg/kg).

• Journal of Animal Science and Technology
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• v.53 no.4
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• pp.341-348
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• 2011

The antagonistic activities against animal entero-pathogenic bacteria were investigated with 444 natural substances fermented by various probiotics. A white rice product fermented (FWR) by Clostridium butyricum IDCC 9207 with a high growth inhibition of Salmonella typhimurium KCTC 2054 and Escherichia coli O157:H7 was selected. Also, a FWR was shown to suppress 8 among 21 pathogenic bacteria. In a mouse model with salmonella (${\times}10^9$ CFU/mouse) infection, 5 samples (200 ${\mu}{\ell}$/mouse/day) were fed to mice (n = 25) for 18 days. A fermented white rice containing C. butyricum IDCC 9207 (FWRCb9207) among 5 samples significantly inhibited the growth of salmonella, while in the control group (PBS, tetracycline) the number of salmonella increased. And the treatment with FWRCb9207 was found to increase the secretory immunoglobulin A (sIgA) level in the feces of salmonella-infected mice. The results obtained in this study suggest that a FWRCb9207 might be utilized as a feed additive in pigs and poultry diets.

• Journal of Environmental Science International
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• v.28 no.2
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• pp.225-233
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• 2019

In this study, we investigated the in vitro anti-biofilm activities of plant extracts of chives (Allium tuberosum), garlic (Allium sativum), and radish (Raphanus sativus L.) against environment harmful bacteria (gram-positive Staphylococcus aureus and, gram-negative Salmonella typhimurium and Escherichia coli O157:H7). In the paper disc assay, garlic extracts exhibited the highest anti-biofilm activity. The Minimal Inhibitory Concentration (MIC) of all plant extracts was generally higher for gram-negative bacteria than it was for gram-positive bacteria. Gram-negative bacteria were more resistant to plant extracts. The tetrazolium dye (XTT) assay revealed that, each plant extract exhibited a different anti-biofilm activity at the MIC value depending on the pathogen involved. Among the plant extracts tested, garlic extracts (fresh juice and powder) effectively reduced the metabolic activity of the cells of food-poisoning bacteria in biofilms. These anti-biofilm activities were consistent with the results obtained through light microscopic observation. Though the garlic extract reduced biofilm formation for all pathogens tested, to elucidate whether this reduction was due to antimicrobial effects or anti-biofilm effects, we counted the colony forming units of pathogens in the presence of the garlic extract and a control antimicrobial drug. The garlic extract inhibited the E. coli O157:H7 biofilm effectively compared to the control antimicrobial drug ciprofloxacin; however, it did not inhibit S. aureus biofilm significantly compared to ciprofloxacin. In conclusion, garlic extracts could be used as natural food preservatives to prevent the growth of foodborne pathogens and elongater the shelf life of processed foods.

• Food Science and Preservation
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• v.31 no.1
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• pp.126-137
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• 2024

In this study, zinc oxide nanoparticles (ZnONPs) were synthesized using three distinct zinc salts: zinc acetate, zinc chloride, and zinc nitrate. These ZnONPs were subsequently utilized in the fabrication of carrageenan-ZnONPs (Car-ZnONPs) composite films. The study assessed influence of the various ZnONPs on the morphological, water vapor barrier, color, optical, and antimicrobial properties of the Car-ZnONPs composite films. The surface morphology and UV-blocking attributes of the composite films were affected by the type of ZnONPs used, but their surface color, transparency, and chemical structure remained unaltered. The composite film's thickness and elongation at break (EB) significantly increased, while the tensile strength significantly decreased. In contrast, film's elastic modulus (EM) and water vapor permeability coefficient (WVP) showed no significant difference. All the composite films with added ZnONPs demonstrated potent antibacterial activity against Escherichia coli O157:H7 and Listeria monocytogenes . Among the carrageenan-based composite films, Car-ZnONPs^ZC showed the highest antibacterial and UV-blocking properties, and its elongation at break was significantly higher than that of the pure carrageenan films. This suggests that ZnONPs composite films have the potential to be used as an active packaging film, preserve the safety of the packaged food and extend shelf life.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.11
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• pp.1509-1517
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• 2004

A study was conducted to determine the safety of feeding processed broiler litter (BL) to beef cattle. The litter was processed by deepstacking, ensiling and composting. The health issues addressed relevant to the safety of feeding litter included pathogenic bacteria, mycotoxins, heavy metals, medicinal drugs and pesticide residues. Exp. 1 evaluated the feed hygiene of processed rice hulls-bedded BL. The presence of pathogenic bacteria in BL was determined before and after deepstacking. A total of 21 BL samples were collected over a 3-year period of commercial and experimental production of BL for beef cattle. Exp. 2 evaluated the safety of meat of cattle fed deepstacked BL. In Exp. 1, there were no pathogenic bacteria, such as coliform, E. coli, E. coli O157:H7, Salmonella, Listeria and Proteus, in deepstacked BL. Levels of heavy metals (Cu, Fe, Mn and Zn) and toxic heavy metals (As, Pb, Cd and Hg) were lower than the commercial feed tolerances. Aflatoxin, medicinal drug and pesticide residues were detected at extremely low levels. In Exp. 2, the meat of the BL-fed animals exhibited few differences in all analyzed items from that of the control group, showing safety from pathogenic microorganisms and heavy metals. When BL was withdrawn for 14 days prior to slaughtering the BLfed cattle, no medicinal drug residues were detected in the meat. Pesticides in the tissues of either group of animals were much lower than the tolerances. In conclusion, processed rice hulls-bedded BL and the meat of cattle fed BL were safe from the potential hazards of pathogenic bacteria, heavy metals, aflatoxin, medicinal drugs and pesticide residues.

• Korean Journal of Veterinary Service
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• v.25 no.2
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• pp.117-126
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• 2002

Contamination levels of pathogenic microorganisms in 145 cases of beef, which were distributed in Gwangju province, had been investigated in each distributed stage and also monitored by general bacterial count and E coli count index. General bacterial count of beef from the slaughterhouse was 10$^4$cfu/g less than the level of promotion(10 cfu/$\textrm{cm}^2$) and E coli count index was also under the level of 10$^2$cfu/$\textrm{cm}^2$ recommended level of the ministry of agriculture and forestry. Pathogenic microorganisms were detected from 23.2% of samples in the consumption stage, 12.5% in the slaughtering stage and 5.6% in the transporting and processing stage. Staphylococcus aureus was isolated in the largest number and its ratio was 9.0%, listeria monocytogenes 5.5% and salmonella spp 1.4%. There were no samples that bacteria had been detected dually. E coli O157:H7 and campylobacter jejuni were not isolated. In raw and chilled beef, isolation rate of pathogenic microorganisms were 13.3% and 16.5% each. Especially in raw beef, L monocytogenes was. isolated in 3 samples among 30 cases (10%) and S aureus in one sample (3.3%). According to a scale of meat store, isolation rates of pathogenic microorganisms were different. It was 28.6% in the small-scale meat store and 16.7% in the large-scale meat store each. Four cases (16.7%) of S aureus were isolated in the large-scale meat store and seven cases (20.0%) of L monocytogenes and 2 cases (5.7%) of salmonella spp were isolated in the small-scale meat store. S aureus was isolated in two places among 10 feeding facilities of the elementary school. This result shows that the sanitation of elementary school feeding facilities is so poor and more careful policy consideration is needed. Eleven strains of S aureus isolated showed ${\beta}$-hemolysis on blood agar, 1 strain ${\alpha}$-hemolysis, and 1 strain ${\gamma}$-hemolysis. Isolated strains of L monocytogenes were reconfirmed in 560 bp by PCR. Conclusively, these results show that the sanitary condition in the stages of slaughtering, transportation-processing and consumption influences the degree of pathogenic microorganisms contamination in beef severely It is necessary to apply thoroughly hazard analysis critical control point in a process of beef distribution and also to develop rapid test methods for microorganism diagnosis. This effort is very important for the supply of safe and clean meat from farm to table and helpful for the improvement of public health.

• Korean Journal of Veterinary Service
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• v.35 no.3
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• pp.223-230
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• 2012

This study was carried out to investigate the heavy metal and microbiological hazards on by-products (liver, omasum, small intestines) of cattle. From April to October in 2011, one hundred and twenty samples were equally collected from slaughterhouse and meat by-product markets in Incheon city. The total bacteria counts and E. coli count were applied to assess the microbiological quality. Food borne bacteria including Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, Clostridium perfringens and E. coli O157:H7 were also determined. The results were obtained as follows: The undesirable grade (more than $10^5\;CFU/cm^2$) was detected in the by-product from 18.3% (slaughterhouse) and 23.3% (by-product markets). The frequency of generic E. coli (more than $10^2\;CFU/cm^2$) from the slaughterhouse was 20.0%, whereas that of the meat by-product markets was 26.7%. Of the samples from slaughterhouse, 3 (5.0%), 5 (8.3%), and 12 (20.0%) samples were contaminated with Salmonella spp, S. aureus, and C. perfringens, respectively. S. aureus and C. perfringens were also detected in 6 (10.0%) and 25 (41.7%) samples in the meat by-product markets, respectively. Nine of 11 S. aureus isolates harbored toxin gene. However, the cpe gene of C. perfringens was not detected among the 37 isolates. The detection rate was higher in August than in February, April and June. The levels of Cd and Pb in all the samples tended to be low (<0.2 mg/kg). This preliminary data could be used for legislation on the regulation and control of microorganism and heavy metal in by-products of cattle.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.2
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• pp.121-126
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• 2018

The purpose of this study was to assess bacteriological hazards in the following 7 kinds of minimally processed shellfish products purchased from Korean seafood retail outlets: raw oysters stored with seawater in polyethylene bags, frozen oysters, raw mussels, frozen mussels, boiled mussels, raw short-necked clam, and frozen short-necked clams, obtained from Korean seafood retail outlets. The total coliform and Escherichia coli counts determined in all samples were detected below regulation limit of the Korean government guidelines (Food Code). In addition, the high-risk bacterial pathogens, Listeria monocytogenes, Salmonella spp., and E. coli O157:H7 were not detected in any samples. Low-risk pathogens such as Staphylococcus aureus and Vibrio parahaemolyticus were detected at levels above $1.0{\times}10^2$ colony forming unit (CFU)/g in some minimally processed shellfish products. Notably, S. aureus was detected in all samples. Raw oysters stored with seawater in polyethylene bags, frozen oysters, and boiled blue mussels are commonly ingested without heating, and therefore these minimally processed shellfish products pose bacteriological hazards. The detection of S. aureus in all shellfish products, an organism indicative of poor personal hygiene, which can grow and multiply during distribution, indicates the necessity of improving the food safety of minimally processed shellfish products.