• Preventive Nutrition and Food Science
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• 제13권4호
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• pp.348-353
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• 2008

Aerobic bacterial growth on Korean pan.fried meat patties as a primary quality deterioration factor was modeled as a function of temperature to estimate microbial spoilage on a real.time basis under dynamic storage conditions. Bacteria counts in the stretch.wrapped foods held at constant temperatures of 0, 5, 10 and $15^{\circ}C$ were measured throughout storage. The bootstrapping method was applied to generate many resampled data sets of mean microbial counts, which were then used to estimate the parameters of the microbial growth model of Baranyi & Roberts in the form of differential equations. The temperature functions of the primary model parameters were set up with confidence limits. Incorporating the temperature dependent parameters into the differential equations of bacterial growth could produce predictions closely representing the experimental data under constant and fluctuating temperature conditions.

• Animal Bioscience
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• 제36권9호
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• pp.1305-1313
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• 2023

Synthetic antioxidants have shown adverse effects on consumers. The review, thus, aims to assess the effect of marinating broiler meat with plant leaves-derived antioxidants potential for improving shelf-life and human health. Broiler meat loss and waste due to spoilage is more than three million kg annually, thus, extending shelf-life by reducing initial microbial load and autoxidation is essential. Adding various antioxidants would reduce oxidation of protein and fatty acids improving nutritional shelf-life through synergic interactions. Antioxidant synergetic effects also improves reduction in microbiota proliferation leading to the delayed development of off flavours and deterioration of meat colour. To reduce initial microbial load and autoxidation effects, the inclusion of polyphenols and antioxidants from varying sources by mixing various antioxidants would lead to improved synergic effects.

• 한국축산식품학회지
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• 제44권1호
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• pp.19-38
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• 2024

Meat contains high-value protein compounds that might degrade as a result of oxidation and microbial contamination. Additionally, various pathogenic and spoilage microorganisms can grow in meat. Moreover, contamination with pathogenic microorganisms above the infectious dose has caused foodborne illness outbreaks. To decrease the microbial population, traditional meat preservation methods such as thermal treatment and chemical disinfectants are used, but it may have limitations for the maintenance of meat quality or the consumers acceptance. Thus, non-thermal technologies (e.g., high-pressure processing, pulsed electric field, non-thermal plasma, pulsed light, supercritical carbon dioxide technology, ozone, irradiation, ultraviolet light, and ultrasound) have emerged to improve the shelf life and meat safety. Non-thermal technologies are becoming increasingly important because of their advantages in maintaining low temperature, meat nutrition, and short processing time. Especially, pulsed light and pulsed electric field treatment induce few sensory and physiological changes in high fat and protein meat products, making them suitable for the application. Many research results showed that these non-thermal technologies may keep meat fresh and maintain heat-sensitive elements in meat products.

• 한국식품조리과학회지
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• 제29권3호
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• pp.267-274
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• 2013

Demand for a rice cake, a popular traditional food in Korea, is rising, but its industrial-scale production is extremely difficult due to its short shelf-life caused by starch retrogradation and microbial spoilage. By means of the sourdough fermentation technique, we attempt to develop rice cakes with a longer shelf-life. Heterofermentative lactic acid bacteria (Weissella koreensis HO20, Weissella kimchii HO22) isolated from kimchi were used to ferment wet-milled rice flour for their abilities to produce exopolysaccharides and to inhibit the microbial spoilage of rice cakes. After 24 hr of fermentation at $25^{\circ}C$, viable cell counts in rice dough increased from $10^6$ CFU/g to $10^8$ CFU/g and total titratable acidity increased from 0.05% to 0.20%, whereas pH decreased from 6.5 to 5.1. Fermented rice flour showed significantly lower peak, trough, and final viscosities as well as breakdown and setback viscosities measured by rapid viscoanalyzer. Both lactic acid bacteria showed in vitro antifungal activity against Penicillium crustosum isolated from rice cakes. The antifungal activity remained constant after the treatments with heat, proteinase K and trypsin, but fell significantly by increase of pH. Rice cakes made of fermented rice flour were found to retard mycelial growth of P. crustosum. The degree of retrogradation as measured by the hardness of the rice cake was significantly reduced by the use of fermented rice flour. The results suggest that use of fermented rice flour has a beneficial role in retarding starch retrogradation and in preventing fungal growth, hence extending the shelf-life of rice cakes.

• Journal of Microbiology and Biotechnology
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• 제21권10호
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• pp.1001-1011
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• 2011

To explore bacterial diversity for elucidating genetic variability in acylhomoserine lactone (AHL) lactonase structure, we screened 800 bacterial strains. It revealed the presence of a quorum quenching (QQ) AHL-lactonase gene (aiiA) in 42 strains. These 42 strains were identified using rrs (16S rDNA) sequencing as Bacillus strains, predominantly B. cereus. An in silico restriction endonuclease (RE) digestion of 22 AHL lactonase gene (aiiA) sequences (from NCBI database) belonging to 9 different genera, along with 42 aiiA gene sequences from different Bacillus spp. (isolated here) with 14 type II REs, revealed distinct patterns of fragments (nucleotide length and order) with four REs; AluI, DpnII, RsaI, and Tru9I. Our study reflects on the biodiversity of aiiA among Bacillus species. Bacillus sp. strain MBG11 with polymorphism (115Alanine > Valine) may confer increased stability to AHL lactonase, and can be a potential candidate for heterologous expression and mass production. Microbes with ability to produce AHL-lactonases degrade quorum sensing signals such as AHL by opening of the lactone ring. The naturally occurring diversity of QQ molecules provides opportunities to use them for preventing bacterial infections, spoilage of food, and bioremediation.

• Journal of Microbiology and Biotechnology
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• 제33권4호
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• pp.419-429
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• 2023

Ultraviolet C (UV-C, 200-280 nm) light has germicidal properties that inactivate a wide range of pathogenic and spoilage microorganisms. UV-C has been extensively studied as an alternative to thermal decontamination of fruit juices. Recent studies suggest that the efficacy of UV-C irradiation in reducing microorganisms in fruit juices is greatly dependent on the characteristics of the target microorganisms, juice matrices, and parameters of the UV-C treatment procedure, such as equipment and processing. Based on evidence from recent studies, this review describes how the characteristics of target microorganisms (e.g., type of microorganism/strain, acid adaptation, physiological states, single/composite inoculum, spore, etc.) and fruit juice matrices (e.g., UV absorbance, UV transmittance, turbidity, soluble solid content, pH, color, etc.) affect the efficacy of UV-C. We also discuss the influences on UV-C treatment efficacy of parameters, including UV-C light source, reactor conditions (e.g., continuous/batch, size, thickness, volume, diameter, outer case, configuration/arrangement), pumping/flow system conditions (e.g., sample flow rate and pattern, sample residence time, number of cycles), homogenization conditions (e.g., continuous flow/recirculation, stirring, mixing), and cleaning capability of the reactor. The collective facts indicate the immense potential of UV-C irradiation in the fruit juice industry. Existing drawbacks need to be addressed in future studies before the technique is applicable at the industrial scale.

• 한국식품과학회지
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• 제17권2호
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• pp.89-94
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• 1985

팽창된 과일 통조림을 수집하여 팽창된 원인이 화학적 반응에 의한 수소팽창 때문인지 또는 미생물에 의한 부패인지를 조사하였고 미생물에 의한 부패로서 효모가 부패 미생물로 밝혀졌을 때는 속 종까지 동정하였다. 전체적으로 볼 때 깐포도 통조림은 수소팽창에 의해 팽창된 비율이 88%였으나 복숭아 통조림은 24% 뿐이었고, 미생물에 의한 부패율이 76%로서 같은 산성 식품이라고 하더라도 이들 두 제품의 주요 팽창원인이 현저히 다르게 나타났는데, 그 이유는 다음과 같이 판단된다. 깐포도 통조림의 정상적인 pH범위(3.1-3.4)는 복숭아 통조림의 pH범위(3.6-4.3)에 비해 낮기 때문에 수소팽창이 잘 일어나고 이와같이 복숭아 통조림의 높은 PH가 미생물 번식에 유리함은 물론 기타의 다른 복숭아 통조림의 제품특성이 가열 살균효과에 영향을 주었을 것으로 추정된다. 그리고 가장 흔히 발견된 부패효모는 Saccharomyces속과 Torulopsis속의 효모로 밝혀졌고 기타 Candida속이나 Pichia 속의 효모도 낮은 빈도로 발견되었다.

• 한국식품과학회지
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• 제23권2호
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• pp.200-204
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• 1991

31종의 식물에서 필요 부위를 선정하여 75% 에탄올이나 물로 추출하여 얻은 추출물로서, 일반적으로 식품의 부패 혹은 변질에 관여한다고 알려진 Bacillus subtilis, Lactobacillus plantarum, Leuconostoc mesenteroides, Pseudomonas fluorescens, Bacillus cereus 등 5종의 세균과 Saccharomyces cerevisiae 등 1종의 효모를 대상으로 항균성을 시험하였다. 실험대상 6종의 모든 미생물에 대하여 항균성을 나타낸 것은 황백의 에탄올 추출물이었으며 산초, 참깨묵, 지치, 졸참나무는 효모를 제외한 5종에 대하여 댓잎, 오동나무, 리기다는 B. subtilis 및 S. cerevisiae 혹은 L. mesenteroides 및 S. cerevisiae 또는 L. mesenteroides 및 P. fluorescens, B. cereus를 각각 제외한 4종에 대하여 항균성을 나타냈고, 균종에 따라 약간의 차이는 있었지만 황백이 가장 높은 항균성을 보였다. B subtilis, L. plantarum 및 L. mesenteroides에는 황백이, P. fluorescens에는 황백과 오배자가 disc diffusion method에서 가장 높은 항균성을 보였다. 에탄올 추출물과 물 추출물을 비교한 결과 거의 대부분 에탄올 추출물의 항균성이 높았으나, 균종에 따라서는 일부 물 추출물에서 항균성을 따로 보이거나 더 높은 경향이 있기도 하였다. 이상과 같이 천연물 중에도 상당한 항균성물질이 존재한다는 것이 확인되었다.

• Journal of Animal Science and Technology
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• 제61권1호
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• pp.47-53
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• 2019

This study was performed to evaluate the microbial and temperature changes of boxed beef during transport and distribution under vacuum and modified atmosphere packaging (MAP), and to compare between excision and swab sampling for 15 days. The top round and striploin (quality grade 1) from Hanwoo steers at 2 days post-slaughter were obtained from a local meat processing plants and chilled at $4{\pm}2^{\circ}C$ in a cold room. The boxes were transported under refrigeration ($4{\pm}2^{\circ}C$) to the laboratory within half an hour. Vacuum and MAP packs were subsequently taken out from cool boxes, and microbiological examinations were carried out at 0, 6, 12, and 24 h of storage time. MAP was more effective than vacuum packaging for the inhibition of total aerobic, lactic acid bacteria and Pseudomonas (p < 0.05). Microbial loads of swab methods were slightly lower than those of excision ones (p < 0.05). The results of this study could be utilized by meat consumers in future studies as well as by manufacturers to determine the ideal storage conditions for cool boxed meat, thus ensuring reduced economic losses due to spoilage.

• 한국식품과학회지
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• 제31권3호
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• pp.788-793
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• 1999

본 연구에서는 오염된 무균포장밥으로부터 미생물의 분리 동정을 실시하고 AESS의 살균효과를 측정하였으며, 이를 취반수로 이용하여 취반미의 pH를 저하시킨 후 오염된 미생물의 사멸 및 생육억제 효과를 검토하였다. 오염된 3종의 시료로부터 총 6주의 오염미생물을 분리하여 생리화학적 방법에 의하여 5주의 Bacillus subtilis와 1주의 B. cereus로 동정하였다. 이 결과는 지방산 분석법에 의한 미생물동정기를 사용하여 확인하였다. AESS의 살균효과는 0.1% NaOCl 및 70% ethanol 용액의 그것과 유사하거나 보다 우수한 것으로 나타났으며, Bacillus spp.를 제외한 다른 시험미생물들은 5초간의 노출로 모두 사멸하였다. Bacillus spp.에 대해서는 AESS가 NaOCl이나 ethanole보다 우수한 살균 또는 성장 억제효과를 갖는 것으로 나타났으며, 5분간의 노출로 모두 사멸하였거나 성장 억제되었다. 또한 AESS를 취반수로 사용하면 pH $3.6{\sim}4.3$ 범위의 취반미를 얻을 수 있었으며, 제조된 밥의 pH는 저장기간 중 거의 변화를 보이지 않았다. 여기에 오염된 무균포장밥으로부터 분리된 Bacillus 균현탁액을 조제하여 접종 밀봉하고 $37^{\circ}C$에서 2주간 저장한 결과 수도수로 제조된 밥에서는 정상적인 성장을 나타냈으나, AESS로 제조된 밥에서는 오염 미생물들의 생육이 완전히 억제되었다.