• KSBB Journal
• /
• v.19 no.4
• /
• pp.291-294
• /
• 2004

The aim of this study was to figure out the antibacterial pattern of leucocin A transformed yeast with culture. Dry cell weight, total secreted protein, and antibacterial activity were increased to 12 hour, after then they showed decrease while protease activity represented the opposite pattern. This implied the production of leucocin A was growth-related. Compared to the result of one hour culture broth, antibacterial activity was about 3.24 fold at 12 hour culture. Maximum growth inhibition rate was 70.57% compared to nontransformed yeast. As the increase of protease in the supernatant, the antibacterial activity was diminished. This study could permit the mass production of bacteriocin to use as antibiotics or food preservatives.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.2
• /
• pp.224-230
• /
• 2006

Microbial contamination levels and legal preservative appropriation in child foods sampled from the neighborhood of elementary schools were investigated. Contamination levels of total aerobic bacteria in seasoned dried fish slices, bread and snacks, sausages, sugar products and dumplings were $1.70\~6.91,\;1.40\~6.66$, 4.50, $3.48\~5.88$, and $4.79\~4.82\;log_{10}$ CFU/g, respectively. Coliforms in four kinds of foods except for dumplings were $2.30\~6.60,\;4.22\~~5.98$, 2.00, and $2.78\;log_{10}$ CFU/g, respectively. Yeasts and molds in those foods were $0.10\~4.23,\;1.66\~4.91,\;1.46\~1.91,\;1.56\~4.26$, and $1.12\~1.84\;log_{10}$ CFU/g, respectively. S. aureus was isolated in $18\%$ of seasoned dried fish slices ($1.00\~2.84\;log_{10}$ CFU/g), $33\%$ of bread and snacks ($1.70\~1.79\;log_{10}$ CFU/g), $50\%$ of sausages ($3.28\;log_{10}$ CFU/g), $22\%$ of sugar products ($2.16\~2.88\;log_{10}$ CFU/g), and $100\%$ of dumplings $(1.18\~3.31\;log_{10}\;CFU/g)$ B. cereus was isolated in $21\%$ of seasoned dried fish slices $(0.70\~2.48\;log_{10}\;CFU/g)$, $50\%$ of bread and snacks $(0.70\;log_{10}\;CFU/g)$, and $11\%$ of sugar products $(0.30\;log_{10}\;CFU/g)$. Both E. coli and Salmonella spp. were not isolated in all samples. Preservative was only labeled on four products among 15 products but preservative on 13 products including 4 products haying an indication of preservative were not detected. Moreover, $0.30\%$ of sorbic acid was detected in one of Squid products . The results of this study indicated that the hygienic level of child foods in Gyeonggi and Incheon was very poor and need to be improved.

• Journal of Food Hygiene and Safety
• /
• v.27 no.4
• /
• pp.449-455
• /
• 2012

The purpose of this study is to evaluate antimicrobial effects of organic acid and some natural occurring antimicrobials against Staphylococcus aureus isolated from various origins (vegetables, peanut, pea leaf, kim-bab, person, perilla leaf, and animal) and to calculate their MIC and MBC values. Five organic acids (acetic, lactic, citric, malic, and propionic acid), three essential oils (carvacrol, thymol, and eugenol), and two other natural antimicrobials (nisin and cinnamic acid) were evaluated for their antimicrobial effects against 113 strains of S. aureus using combination treatments. Propionic acid (7%), nisin (1%), thymol (1%), carvacrol (1%) showed antimicrobial activities against S. aureus strains in agar disc diffusion test. And, carvacrol, thymol, and nisin were found to be the most effective with the lowest MIC values of 0.0313%, 0.0625%, and 0.0625% against S.aureus, respectively. Propionic acid (0.2313%) and citric acid (0.6000%) were the most effective among organic acids tested. Therefore, these five antimicrobials were selected for next combination treatments. Combination of propionic acid and citric acid were showed the strongest inhibitory effectiveness against S. aureus among combination treatments. These results suggest that organic acid such as propionic and citric acid, and natural occurring antimicrobial such as nisin, carvacrol, and thymol might be possibly used as preservatives for inhibiting S. aureus in foods.

• Journal of Food Hygiene and Safety
• /
• v.38 no.5
• /
• pp.311-318
• /
• 2023

This study was performed to determine the contents of propionic, benzoic, and sorbic acids in dried seasoned seafood products (n=27) sold in Korea. Propionic acid was determined using a gas chromatogramphy-flame ionization detector. Benzoic and sorbic acid were analyzed by using a high-performance liquid chromatography-diode array detector. Benzoic acid was not detected in the dried seasoned seafood products; however, propionic and sorbic acid were detected in some samples. The concentrations of propionic acid and sorbic acid were up to 125.10 mg/kg and 658.18 mg/kg in dried seasoned seafood products, respectively. Of eight samples labeled with potassium sorbate, sorbic acid was detected in seven of them. The detected sorbic acid levels in these samples met the regulations for sorbic acid usage in Korea. The propionic, benzoic, and sorbic acid contents of dried seasoned seafood products determined in this study can provide basic data for safety management of dried seasoned seafood products in future.

• Journal of the Korean Applied Science and Technology
• /
• v.37 no.2
• /
• pp.374-384
• /
• 2020

This study was carried out to investigate the food value of Dae Hong(Prunus mume Siebold et Zucc), and also to analyzed contents of general component, free sugar, organic acid, amino acid, mineral element, and vitamins. The carbohydrate of Dae Hog showed the highest content of 46.8±0.92%, followed by crude protein(18.9±0.01%), moisture content(11.8±0.13%), and crude fiber, crude fat, ash(5.7±0.94~6.7±0.52%). In case of free sugar contents, 5 types were found. Most of them were mannitol and fructose. 6 mineral contents were also found, too; K and P showed the highest level. The total phenol content was 615.99±0.52 mg/100 g. Including seven different type of essential amino acids, the total amino acid content of Dae Hong was 121.42 mg/g. These results point out the potential of Dae Hong as innovative food for health or to be incorporated in new products as natural food preservatives and supplements.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.4
• /
• pp.692-696
• /
• 2001

To develop natural food preservatives, ethanol and water extracts were prepared from the coriander (Coriandrum sativum L.) and antimicrobial activities were examined against 10 microorganisms which were food borne pathogens and/or food poisoning microorganisms and food-related bacteria and yeasts. Ethanol extract exhibited antimicrobial activities for the microorganisms tested, but not on lactic acid bacteria and yeast. Especially, minimum inhibitory concentrations (MIC) for Bacillus subtilis and Bacillus cereus were as low as 0.25mg/mL. antimicrobial activity of the ethanol extract was not destroyed by the heating at 121$^{\circ}C$ for 15min and not affected by pH. The ethanol extract of coriander exhibiting high antimicrobial activities was fractionated in the order of hexane, chloroform, ethylacetate and butanol fractions to test antimicrobial activity. The highest antimicrobial activity adjust bacteria tested was found in the ethylacetate fraction.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.6
• /
• pp.829-832
• /
• 2003

To develop natural food preservatives, ethanol and water extracts were prepared from the cornus (Cornus of officianalis) and antimicrobial activities were examined against 10 microoganisms which were food borne pathogens and/or food poisoning microoganisms, food-related bacteria and yeasts. Ethanol extract exhibited antimicrobial activity for the microoganisms tested, except lactic acid bacteria and yeast. Especially, minimum inhibitory concentrations (MIC) of the ethanol extracts were determined as 0.25 mg/mL against bacteria and 2 mg/mL against target lactic bacteria and yeasts. Antimicrobial activity of the ethanol extracts were not destroyed by the heating at 121$^{\circ}C$ for 15 min and not affected by pH. The ethanol extract of cornus exhibiting high antimicrobial activities were fractionated in the other of diethylether and butanol fractions to test antimicrobial activity The antimicrobial activity adjust bacteria test was highest in the ethanol fraction.

• Journal of Life Science
• /
• v.33 no.1
• /
• pp.91-101
• /
• 2023

Bacteriocins are antimicrobial peptides synthesized on ribosomes, produced by bacteria, that inhibit the growth of similar or closely related bacterial strains. Since the discovery of nisin, many bacteriocins with unique structures and various modes of antibacterial activity have been described, and genes encoding production, secretion, and immunity have been reported. Nisin is one of the bacteriocins applied in cheese, liquid eggs, sauces and canned foods. Many of the bacteriocins of the genus Bacillus belong to lantibiotics, which are modified peptides after translation. Other genus Bacillus also produce many non-lantibiotic bacteriocins. Bacteriocins of the genus Bacillus are sometimes becoming more important because of their broader antibacterial spectrum. Bacteriocins are considered attractive compounds in the food and pharmaceutical industries to prevent food spoilage and growth of pathogenic bacteria. Bacteriocins can be used as biological preservatives in a variety of ways in the food system. Biopreservation refers to extending shelf life and improving safety of foods using microorganisms and/or their metabolites. The demand for new antimicrobial compounds has generated great interest in new technologies that can improve food microbiological safety. Applications of bacteriocins are expanding from food to human health. Today, many researchers are shifting their interest in bacteriocins from food preservation to the treatment of bacteria that cause infections and antibiotic-resistant diseases. This exciting new era in bacteriocin research will undoubtedly lead to new inventions and new applications. In this review, we summarize the various properties and applications of bacteriocins produced by the genus Bacillus.

• Korean Journal of Food Science and Technology
• /
• v.45 no.5
• /
• pp.565-570
• /
• 2013

This study investigated the detection of naturally occurring preservatives in fermented soybean products. Benzoic acid was identified in all of the analyzed samples (gochujang, ganjang, doenjang, and cheonggugjang). The amounts of benzoic acid were in the range of 0.85-11.69 ppm in gochujang, 1.13-7.95 ppm in ganjang, 0.74-17.77 ppm in doenjang, and 1.03-7.64 ppm in cheonggugjang. Propionic acid was found in 24 of 29 gochujang samples, 21 of 30 ganjang samples, 31 of 33 doenjang samples, and 28 of 30 cheonggugjang samples. The amounts of propionic acid ranged from N.D. (not detected) to 49.29 ppm in gochujang, N.D. to 144.67 ppm in ganjang, N.D. to 309.14 ppm in doenjang, and N.D. to 113.07 ppm in cheonggugjang. Among the fermented soybean products, doenjang had the highest average benzoic acid content whereas cheonggugjang had the highest average propionic acid content.

• Journal of Food Hygiene and Safety
• /
• v.16 no.2
• /
• pp.89-95
• /
• 2001

This study was conducted to find material having antibacterial activity. The effects of preservatives, antibiotics and oriental medicines on growth of teated microorganisms were investigated. The growth of all tested bacteria was inhibited by water extract of Schizandra chinensis. Antibacterial activity on the concentration of Schizandra chinensis extract was tested. The growth of Escherichia coli W3110, Enterobacter colacae MG82 and Salmonella typhimurium was extraordinarily inhibited by more than 0.2% concentration of Schizandra chinensis extract. The specific growth rate of Escherichia coli W3110, Enterobacter cloacae ME82 and Salmonella typhimurium under control conditin had mean values of 0.514(hr￣), 0.381(hr￣) and 0.489(hr￣), respectively. When 0.2% of Schizandra chinensis extract was added, specific growth rates of Escherichia coli W3110, Enterobacter colacae MG82 and Salmonella typhimurium wre decreased, compared to contorl, in 1.26, 2.23 and 1.50 fold, respectivley. Minimal inhibiotory concentration of Schizandra chinensis extract was 0.25% on the tested microorganisms The growth of Enterobacter cloacae MG82 was more inhibited by Schizandra chinensis extract than other tested microorganisms.