• Preventive Nutrition and Food Science
• /
• v.5 no.3
• /
• pp.148-152
• /
• 2000

Mussel adhesive protein (MAP) was extracted from Korean Mytilus edulis and then partially purified using Sephacryl S-300 gel permeation chromatography and reversed-phase high performance liquid chromatography. As an indicator of adhesiveness, is 3,4-dihydroxyphenylalanine (DOPA) content was determined. Its DOPA/protein ratio of 0.19 was higher than those of other reports, indicating a good adhesive. The partially purified MAP was confirmed by acid-urea polyacrylamide gel electrophoresis using cetylpiridinium bromide as a cationic detergent. Sea mussel hydrolysates were prepared using three commercial proteases to provide value-added functional materials and their angiotensin converting enzyme (ACE) inhibitory activities were determined. Among hydrolysates of sea mussel, Protamex was the best and further purification would improved ACE inhibitory activity.

• Microbiology and Biotechnology Letters
• /
• v.47 no.2
• /
• pp.183-194
• /
• 2019

The consumption of fresh vegetables has been related to recurrent outbreaks of foodborne diseases (FBD) worldwide. Therefore, the development of effective alternative technologies is necessary to improve the safety of these products. This study aimed to isolate and identify epiphytic lactic acid bacteria (LAB) from fresh fruits and leafy vegetables and characterize their antagonistic capacity due to their ability to produce bacteriocins or antibacterial compounds. For this, 92 LAB isolates from fruits and leafy vegetables were screened for antagonistic activity. Two strains with the highest and broadest antagonistic activities were selected for further characterization; one from cantaloupe melon (strain CM175) and one from cilantro leaves (strain C15). The cell-free supernatants (CFS) of CM175 and C15 were found to exhibit antagonistic activity against FBD-causing pathogens. The CM175 and C15 strains were identified as Pediococcus pentosaceus and Lactobacillus graminis, respectively. Notably, the P. pentosaceus CM175 CFS stopped the growth of Salmonella Typhimurium, Salmonella Saintpaul, Staphylococcus aureus, and Listeria monocytogenes, and delayed Escherichia coli O157:H7 growth. Moreover, L. graminis C15 CFS delayed the growth of all indicator pathogens, but did not completely stop it. Organic acids and bacteriocin-like molecules were determined to be possibly exerting the observed antagonistic activity of the identified LAB strains. Thus, application of the antagonistic compounds produced by Pediococcus pentosaceus and Lactobacillus graminis could be a novel and ecological strategy in developing antimicrobial biopreservatives for the food industry and mitigating FBD by reducing the biological contamination in fruit and vegetable orchards, mainly via their potential in controlling both gram-negative and gram-positive pathogenic bacteria.

• Culinary science and hospitality research
• /
• v.17 no.4
• /
• pp.316-325
• /
• 2011

The property of deep frying oil is one of die important factors in fried food quality. The purpose of this study is to identify die quality of deep frying oil in continuous usages for 4 days by two types of fryers: traditional and modified fryers. After frying polk cutlets, die flying oil was kept not only for several physical analyses such as color, viscosity, and water content but also for quality analyses of flying oil such as free fatty acid, double bond changes and oxidative rancidity formation. The fried oil by a traditional flyer was significantly increased in die physical values of color and viscosity than that by a modified fryer. In die acid value, the fried oil by a traditional fryer was significantly increased in free fatty acid than that by a modified fryer while die iodine value was significantly decreased in die fried oil by a traditional fryer when compared to control oil and fried oil by a modified fryer. In die peroxide value as an indicator of primary oxidation products, die fried oil by both fryers was significantly increased till die second day but decreased in die value after die third day because of unstable hydroperoxides' decomposition. In die p-anicidine value as an indicator of secondary oxidation products, die fried oil in a traditional fryer was significantly increased in die value than that in a modified fry.

• Preventive Nutrition and Food Science
• /
• v.2 no.2
• /
• pp.109-120
• /
• 1997

In order to elucidate roles of lactic acid bacteria(LAB) for the antibiosis occurring in th fermenting environment of Kimchi, 2.052 strains of LAB were isolated from Kimchi. Fifty tow strains which showed antagonistic effect against 4 indicator strains were finally selected and investigated. Based upon responses to protease treatment, antibiosis of the 52 strains of LAB were classified into 3 types. Type A antibiosis resulted from action of antibiotic-like substances which were not affected by protease treatment and which had broad action spectra against even natural inhabitants of Kimchi. Type B antibiosis was due to bacteriocin-like substances which were very sensitive to treatment of protease and more effective against foreign bacteria than original inhabitant microflora. Type C antibiosis was owing to proteinaceous compounds which were activated or induced by the presence of protease and then exerted antibacterial activities. Therefore, lactic acid bacteria appeared to contribute to antibiosis of Kimchi by the concerted action of these three different types of antibacterial compounds. As one of model system for type B bacteriocin, the antagonistic compound produced by LAB31-9 as well as th producer strain itself was further charaacterized. Strain LAB31-9 was identified as L. casei. Bacteriocin produced by LAB31-9 was proteinaceous and stable over wide range of pH and to various solvents, but very labile to heat treatment. Its mode of action was bactericidal. Based upon these data, bacteriocin produced by LAB31-9 was named as 'caseicin K319'. Genetic determinant for the bacteriocin production of LAB31-9 was located in the chromosome.

• YAKHAK HOEJI
• /
• v.40 no.6
• /
• pp.670-678
• /
• 1996

The combinations of N-4-salicyloamido-2-amino-6-piperidinopyrimidine 3-oxide (Salmi) and two transitional metals were colored. Among metals, Fe(III) made a distinct colored comp lex with Salmi. The mole ratio of Salmi and Fe(III) in the complex was 1:1. This Salmi-Fe(III) complex was recrystallized in Hexane/Acetone(=10/1, v/v) and investigated its physicochemical properties. The color of this complex was changed by pH.; deep violet pink in acids, orange in neutral, and yellow in bases. The range of color change was approximately 0.7 pH unit. Acid-base titration of various acidic or basic drugs using Salmi-Fe(III) complex as an indicator showed good accuracy and reproducibility.

• Journal of Microbiology and Biotechnology
• /
• v.32 no.1
• /
• pp.64-71
• /
• 2022

The discarding of wastes into the environment is a significant problem for many communities. Still, food waste can be used for lactic acid bacteria (LAB) growth. Here, we evaluated three growth media equivalent to de Mann Rogosa Sharpe (MRS), using apple bagasse, yeast waste, fish flour, forage oats, and cheese whey. Cell-free supernatants of eight LAB strains were tested for antimicrobial activity against nine indicator microorganisms. The supernatants were also evaluated for protein content, reducing sugars, pH, and lactic acid concentration. Cell-free supernatants from fish flour broth (FFB) LAB growth were the most effective. The strain Leuconostoc mesenteroides PIM5 presented the best activity in all media. L. mesenteroides CAL14 completely inhibited L. monocytogenes and strongly inhibited Bacillus cereus (91.1%). The strain L. mesenteroides PIM5 consumed more proteins (77.42%) and reducing sugars (56.08%) in FFB than in MRS broth (51.78% and 30.58%, respectively). Culture media formulated with agroindustrial wastes positively improved the antimicrobial activity of selected LAB, probably due to the production of antimicrobial peptides or bacteriocins.

• Journal of Food Hygiene and Safety
• /
• v.37 no.4
• /
• pp.216-224
• /
• 2022

This study was aimed at validating the analysis methods for deacetylasperulosidic acid (DAA), total sugar, galacturonic acid, glucose, and galactose, which are the indicator components of fermented Morinda citrifolia polysaccharide extract (Vitalbos). We modified the previously reported methods for validating the analytical methods. The specificity, linearity, precision, accuracy, limit of detection (LOD), and limit of quantification (LOQ) were measured using phenol-sulfuric acid method and high-performance liquid chromatography (HPLC). The retention time and spectrum of the standard solution of Vitalbos coincided, confirming the specificity. The calibration curve correlation coefficient (R²), of five indicator components, ranged from 0.9995-0.9998, indicating excellent linearity of 0.99 or more. The intra-day and inter-day precision range of the assay was 0.14-3.01%, indicating a precision of less than 5%. The recovery rate was in the range of 95.13-105.59%, presenting excellent accuracy. The LOD ranged from 0.39 to 0.84 ㎍/mL and the LOQ ranged from 1.18 to 2.55 ㎍/mL. Therefore, the analytical method was validated for DAA, total sugar, galacturonic acid, glucose, and galactose, in Vitalbos. The indicator component content in Vitalbos was determined using a validated method. The contents of DAA, total sugar, galacturonic acid, glucose, and galactose were 2.31±0.06, 475.92±5.95, 72.83±1.05, 71.63±2.44, and 67.30±2.31 mg/g of dry weight, respectively. These results suggest that the developed analytical method is efficient and could contribute to the quality control of Vitalbos, as a healthy functional food material.

• Journal of Food Hygiene and Safety
• /
• v.39 no.2
• /
• pp.61-71
• /
• 2024

In this study, we analyzed chlorogenic acid indicator components in preparation for the additional listing of green coffee bean extract in the Health Functional Food Code and optimized caffeine for simultaneous analysis. We extracted chlorogenic acid and caffeine using 30% methanol, phosphoric acid solution, and acetonitrile-containing phosphoric acid and analyzed them at 330 and 280 nm, respectively, using liquid chromatography. Our analysis validation results yielded a correlation coefficient (R²) revealing a significance level of at least 0.999 within the linear quantitative range. The chlorogenic acid and caffeine detection and quantification limits were 0.5 and 0.2 ㎍/mL and 1.4, and 0.4 ㎍/mL, respectively. We confirmed that the precision and accuracy results were suitable using the AOAC validation guidelines. Finally, we developed a simultaneous chlorogenic acid and caffeine analysis approach. In addition, we confirmed that our analysis approach could simultaneously quantify chlorogenic acid and caffeine by examining the applicability of each formulation through prototypes and distribution products. In conclusion, the results of this study demonstrated that the standardized analysis would expectably increase chlorogenic acidcontaining health functional food quality control reliability.

• Korean Journal of Food Science and Technology
• /
• v.34 no.2
• /
• pp.311-318
• /
• 2002

A new bacteriocin producing lactic acid bacteria having antagonistic activity against Lactobacillus plantarum, was isolated from Kimchi. It was identified as Leuconostoc mesenteroides, and designated as Leuconostoc mesenteroides B7. The bacteriocin from Leuconostoc mesenteroides B7 named as bacteriocin B7 was stable in the pH range $2.5{\sim}9.5$. Bacteriocin B7 was active over a wide temperature range from $4^{\circ}C$ to $120^{\circ}C$. It was inactivated by proteinase K, trypsin, ${\alpha}-chymotrypsin$, and protease treatments indicating its proteinous nature. Tricine-SDS-PAGE of the purified bacteriocin B7 showed the presence of a single band, having a molecular mass of about 3,500 dalton. Mixed culture of the producer and the indicator, Lb. plantarum KFRI 464 or Lb. delbruekii KFRI 347, increased production of bacteriocin B7. This result suggested the presence of bacteriocin inducing factor in the indicator strain. The inducing factor was localized in cell debris and intracellular faction of the indicator cell, Lb. plantarum KFRI 464. Treatment of the inducing factor with proteinase K destroyed inducing activity. This result strongly suggested that the inducing factor is a protein.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.23 no.1
• /
• pp.37-45
• /
• 2017

To visually identify the spoilage of chicken breasts, a three layered freshness indicator consisting of PET/bromocresol green (BCG)-ethylene vinyl acetate (EVA)-acetic acid (AA) composite layer/porous substrates was successfully prepared and their performance were simulated at 20% of $CO_2$ and 4 different trimethylamine (TMA) concentrations to evaluate color change at minimal spoilage level. The visibility and range of color changes of the as-prepared indicators responding to TMA concentration as a simulant were strongly dependent on the concentrations of BCG and AA. As the BCG content increased, the visibility of color change in the freshness indicators was apparently improved and the range of color change could be controlled by contents of AA. Among the as-prepared freshness indicators, 'G0.12_A0.5' which consisting 0.12g of BCG and 0.5g of AA was selected as an optimum composition due to the highest visibility at TMA 20 mg% corresponding to the minimal spoilage level. The color of the indicator changed from yellow to green for spoilage indication of chicken breast, which could be easily seen with the naked eyes and well consistent with the simulation results. It is expected that our developed freshness indicator can be useful in monitoring various food freshness and quality.