• Food Science and Industry
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• v.52 no.3
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• pp.261-271
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• 2019

Gut microbiome have recently provided evidence that the gut microbiota are capable of greatly influencing all aspects of physiology and immunology. Although a number of recent studies have shown that probiotics can modulate gut microbiota structure, the mechanism underlying this effect remains to be elucidated. In a disease state, the relative abundances of beneficial gut bacteria are generally reduced, which is restored by constant probiotic supplementation. Oral administration of probiotics improved the disease state by (1) inducing differentiation and function of regulatory T cells, (2) reducing inflammatory response, (3) modulating the gut environment, and (4) increasing the proportions of short-chain fatty acid- or beneficial metabolite-producing gut microbiota including the genera Bifidobacterium, Faecalibacterium, Akkermansia, etc. In this review, current knowledge on how probiotics can influence host's health by altering gut microbiota structure and on how probiotics and beneficial gut bacteria can be applied as next-generation probiotics will be discussed.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.297-305
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• 2022

Antioxidants are food additives that extend the shelf life of food products by preventing lipid rancidity caused by active oxygen. They can either be naturally-derived or manufactured synthetically via chemical synthesis. In this study, method validation of five synthetic antioxidants, namely butylated hydroxyanisole, butylated hydroxytoluene, tertiary butylhydroquinone, propyl gallate, and disodium ethylenediaminetetraacetic acid, was performed using a high performance liquid chromatography-ultraviolet visible detector, and the method applicability was evaluated by analyzing foods containing antioxidants. The coefficient of determination (R²) average was 0.9997, while the limit of detection and limit of quantification were 0.02-0.53 and 0.07-1.61 mg/kg, respectively. The intra and inter-day accuracies and precisions were 83.2±0.7%-98.7±2.1% and 0.1%-5.7% RSD, respectively. Inter-laboratory validation for accuracy and precision was conducted using the Food Analysis Performance Assessment Scheme quality control material. The results satisfied the guidelines presented by the AOAC International. In addition, the expanded uncertainty was less than 16%, as recommended by CODEX. Consequently, to enhance public health safety, the results of this study can be used as basis data for evaluating the intake of synthetic antioxidants and assessing their risks in Korea.

• Journal of Food Hygiene and Safety
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• v.37 no.5
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• pp.356-363
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• 2022

To investigate the functional activity of different citrus fruit peels, antioxidant compounds in 70% ethanol extracts of mandarin, lemon, orange, and grapefruit peel powders were identified, and antioxidant and antibacterial activities were quantitated. Mandarin peel contained the highest content of total phenolic compounds and total flavonoid substances (21.46±0.12 mg GAE/g and 11.57±0.05 mg RE/g, respectively). The total phenolic compound content of the three other citrus fruits was 14.16±0.18-18.44±0.07, and their total flavonoid content was 5.51±0.10-7.46±0.09 mg RE/g. DPPH radical scavenging activity was the highest in lemon peel (87.64±0.21%), and mandarin peel displayed the best antioxidant activity with respective ABTS radical scavenging activity and FRAP measurements of 43.20±0.61% and 78.82±1.06 mM TE/g. Grapefruit peel antimicrobial activity increased with treatment time, and was the most potent among the four tested citrus species, inhibiting Staphylococcus aureus by about 4.05 log cycle. These findings demonstrate that mandarin and grapefruit peel can be used to prevent oxidation, improve food storage capabilities, and potentially preserve food quality.

• Food Science and Preservation
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• v.16 no.6
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• pp.875-883
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• 2009

We investigated the effects of manufacturing method on the quality of beef jerky using electron micrography. Six types of beef jerky were prepared by the addition of sugar (A), licorice (B), one of three kinds of spice extract (clove: C, fennel fruit: D, and Chungyang green pepper extract: E), or a mixture of all spice extracts (F). Microstructural changes in beef jerky during preparation by drying, with respect to drying method and the nature of the added spice extract, were observed by scanning electron micrography (SEM) and transmission electron micrography (TEM). The latter technique showed that the microstructure of fresh meat showed actin and myosin in myofibril lines, and also mitochondria and inner membranes. Beef muscle structure was broken at many myofibril lines and decomposition of inner membrane material was evident after seasoning. SEM of air-blast dried beef jerky with added medicinal herb extracts showed both large spaces and regular myofibrils, whereas hot air-dried beef jerky had no spaces and the muscle myofibrils were still evident. After review of all available micrographs from SEM and TEM, we concluded that use of medicinal herb extracts could be helpful in preserving the muscle myofibril structure during drying, and the air-blast drying method is recommended to optimize the textural quality characteristics of beef jerky.

• Korean Journal of Microbiology
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• v.47 no.3
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• pp.241-248
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• 2011

The use of synthetic additives for preservation and enhancement of the market quality of food products has been emerging as a societal issue in terms of safety as well as changes in consumption patterns. Various research related to natural additives is being conducted to address these issues. This study examined the antibacterial effects of 79 types of medicinal herbs used as oriental remedies on bacteria isolated from beverages of damaged marketable quality. The antibacterial effects of methanol extracts on 13 Bacillus sp. and three Paenibacillus sp. were evaluated. We found that 43 of the herbal medicines analyzed had antibacterial effects on the isolated bacteria. Of those, eight were selected, and their antibacterial effects were further examined using water, ethanol, methanol, and ethyl acetate as solvents. The results revealed that Prunus mume, Rhus javanica, and Coptis japonica had excellent antibacterial effects against the isolated bacteria. In particular, they exerted greater antibacterial effects when water and ethanol were used as solvents. This result indicates the possibility of developing natural additives using these substances. Since P. mume in particular, has not been sufficiently studied compared to other herbal medicines, it presents an opportunity for additional investigation and the possibility for development as a new product in the future.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.276-284
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• 2008

A lactic acid bacterium having antifungal activity was isolated from kimchi. It was identified as Lactobacillus plantarum based on its morphological and biochemical properties, and 16S rRNA sequence, and designated as Lb. plantarum AF1. This isolate inhibited the growth of Aspergillus flavus ATCC 22546, A. fumigatus ATCC 96918, A. petrakii PF-1, A. ochraceus PF-2, A. nidulans PF-3, Epicoccum nigrum KF-1, and Cladosporium gossypiicola KF-2 under a dual culture overlay assay. Also, the antimicrobial activity was found to be active against various species of Gram-positive and Gram-negative bacteria. The antifungal activity was found to be stable after heat ($121^{\circ}C$, 15 min) and proteolytic enzyme treatment, but it was unstable over pH 5.0. The antifungal compound(s) was estimated to have a low molecular mass (below 3,000 Da).

• Korean Journal of Food Science and Technology
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• v.39 no.1
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• pp.66-70
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• 2007

Lactobacillus fermentum YL-3 was encapsulated to increase acid tolerance and its total viability. After micro-encapsulation of L. fermentum YL-3 cells with sodium alginate and soybean oil, the morphology of the microcapsule was observed using confocal laser scanning microscopy (CLSM) after staining with pyronin Y and fluorescein isothiocyanate. The sizes of the microcapsules were 120-126 ${\mu}m$, 444-486 ${\mu}m$ and 401-463 ${\mu}m$ when manufactured at pH 2, 3 and 4, respectively. The microcapsule could hold live cells of L. fermentum YL-3 up to $1.2{\times}10^{7}$, $8.1{\times}10^{7}$ and $1.1{\times}10^{8}$ CFU/mL at pH 2, 3 and 4, respectively. The acid tolerance and preservative ability of L. fermentum YL-3 in microcapsule and macrocapsule at $4^{\circ}C$ and $25^{\circ}C$ were tested. L. fermentum YL-3 cells were evenly located in the alginate capsule matrix structure and the firmness of microcapsule was highest at pH 2. Micro-encapsulation showed the most effective acid tolerance at pH 2.0 and preservation of viability at $4^{\circ}C$. However, at $25^{\circ}C$, the macrocapsules showed more effective cell protection than the microcapsules. The application range for microcapsules could be wider than for macrocapsules in the food industry.

• Food Science and Preservation
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• v.16 no.2
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• pp.139-146
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• 2009

Whole and stem-off cherry tomatoes were packaged using perforated films(LF05, LF10, LF20, and LF40). Gas composition(ethylene, $O_2$, and $CO_2$), firmness(compression and penetration force), color, brix degree, acidity, and total microbial counts were assessed during storage at $10^{\circ}C$ and 85% relative humidity. Gas composition varied with film gas permeability, indicating that modified atmospheric(MA) conditions were achieved. Firmness fell during storage; samples packed using LF05 showed the lowest firmness, corresponding to low gas transmission conditions. L(lightness) and a(redness) values respectively decreased and rose slightly with increasing storage time, but the b(yellowness) values fell notably. Film permeability significantly affected acidity and soluble solid levels. When LF40 packaging was used, acidity and brix scale changes were similar to those seen after PET container packaging. Total microbial counts increased with time after packaging in most films, and pretreatment differences were not significant. Microflora varied between stem on/off tomatoes. Skin wrinkling and juice appearance were common in tomatoes stored in PET containers and LF films of low gas permeabilities(LF05, LF10, and LF20). White molds were partially found on stem-on tomatoes stored using packaging systems. When film packagings were compared, LF40 was optimal, permitting minimal pretreatment yet offering maximal sanitation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.207-211
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• 2004

This study has been investigated the effect of different concentrations (0%, 0.05%, 0.1%, 0.5% and 1.0%) of M.W. 120 kDa of chitosan on improvement of shelf-life and quality in the spicy beef meat. The spicy beef meat without chitosan has not shown the extended effect of storage. However, concentration of more than 0.1% of chitosan have a very strong effect on shelf-life improvement of spicy beef meat. In antioxidation, spicy beef meat with 1.0% of chitosan has shown remarkable effect. The pH value and water holding capacity of these spicy beef meat revealed no significant differences among various concentration of chitosan treatments during storage periods. The value of red color was stable in samples treated with chitosan during period of storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.730-735
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• 2004

The effects of cook-chill and sous-vide upon the vitamin retention and acceptance of soybean sprout muchim and soybean sprouts soup were evaluated. When the sous-vide packaged soybean sprout muchim was stored at 3$^{\circ}C$ for 1, 3, and 5 days, the contents of thiamin, riboflavin, and ascorbic acid were not changed. However, the nutrient contents were changed in sous-vide packaged soybean sprouts soup stored at the same conditions at each storage time up to 5 days. The contents of thiamin, riboflavin, and ascorbic acid showed the lowest level at 5 days after storage. Regarding customer's acceptance of sous-vide packaged soybean sprout muchim compared to the freshly cooked one, the former had a higher score in taste and color than the latter. Overall acceptability of the sous-vide soybean sprout muchim had a lower score than that of the freshly cooked one, but the sensory characteristics did not show any significant difference between them. The freshly cooked soybean sprout soup had higher scores in taste, flavor, color, texture, appearance, and overall acceptability than the son-vide packaged soybean sprout soup. The former, however, had a significantly higher score in color (p＜0.05) and the overall acceptability (p＜0.01) than the latter.