• 한국축산식품학회지
• /
• 제43권3호
• /
• pp.402-411
• /
• 2023

This study was conducted to investigate the bactericidal effect of nisin (Nisin) only, atmospheric pressure plasma (APP) only, and a combination of APP and nisin (APP+Nisin)(APP+Nisin) on beef jerky and sliced ham inoculated with Escherichia coli O157:H7, gram-negative bacteria. The bactericidal effect against E. coli O157:H7 and Listeria monocytogenes was confirmed using a nisin solution at a concentration of 0-100 ppm, and APP+Nisin was tested on beef jerky and sliced ham using 100 ppm nisin. Beef jerky and sliced ham were treated with APP for 5 min and 9 min, respectively. In the bacterial solution, 100 ppm nisin out of 0-100 ppm nisin exhibited the highest bactericidal activity against L. monocytogenes (gram-positive bacteria; p<0.05); however, it did not exhibit bactericidal effects against E. coli O157:H7 (gram-negative bacteria). The APP+Nisin APP+Nisin exhibited a 100% reduction rate in both E. coli O157:H7 and L. monocytogenes compared to the control group, and was more effective than the Nisin. The APP+Nisin decreased the number of colonies formed by 0.80 and 1.96 Log CFU/g for beef jerky and sliced ham, respectively, compared to the control, and exhibited a higher bactericidal effect compared to the Nisin (p<0.05). These results demonstrate the synergistic bactericidal effect of APP and nisin, providing a possible method to improve the limitations of nisin against gram-negative bacteria. In addition, this technology has the potential to be applied to various meats and meat products to control surface microorganisms.

• 한국근적외분광분석학회:학술대회논문집
• /
• 한국근적외분광분석학회 2001년도 NIR-2001
• /
• pp.2122-2122
• /
• 2001

The ultra-high pressure technology fur the preservation of foods is under intense research to evaluate its potential as an alternative or complementary process to traditional methods of food preservation. Traditional processing methods usually need a large amount of energy, may cause unwanted reactions in the food, leading to cooked flavor and loss of vitamins, etc. The application of ultra-high hydrostatic pressure for food processing consists of subjecting the food to pressures in the range of 100-1000 ㎫. The ultra-high pressure inactivates the microorganisms and some enzymes, promotes the germination of spores and extends the shelf-life of the foods. This new technology follows the “minimal processing” concept minimizing the quality degradation, saving the vitamins, essential nutrients and flavors as well as utilizing less energy. We joined the research team at our University involved in the mentioned technology using an ultra-high pressure equipment, recording of the near infrared spectra and signal response of a chemosensor array (electronic nose) of their meat (beef and pork), vegetable and fruit samples exposed to different pressure. The results of our investigations achieved by evaluating the measured data using PCA and PQS methods will be presented.

• Preventive Nutrition and Food Science
• /
• 제8권2호
• /
• pp.191-195
• /
• 2003

We investigated the effects of gamma irradiation on the microbiological, chemical and sensory qualities of bulgogi, a traditional Korean meat product. Gamma irradiation reduced the number of coliform bacteria and bacterial colonies counted in Salmonella-Shigella selective agar to a non-detectable level. Thermophillic microorganisms (mainly Bacillus spp.) in bolgogi refrigerated for 20 days were also significantly reduced by 3 log cycles by 2.5 to 7.5 kGy of irradiation, compared to the control. Electron donating ability and shear force of ready-to-cook bulgogi was not significantly affected by gamma irradiation. Irradiation increased the 2-thiobarbituric acid reactive substances (TBARS) value. The irradiated, raw, ready-to-cook bulgogi had significantly higher scores in color and appearance than those of non-irradiated controls from sensory evaluation. The overall acceptance of cooked bulgogi had higher scores in non-irradiated or 2.5 kGy-irradiated bulgogi than the 5.0- or 7.5-kGy irradiated counterparts. In conclusion, irradiation at 2.5 kGy is recommended as a method to improve shelf-life, safety, and to achieve acceptable quality of ready-to-cook bulgogi without any adverse changes in the sensory characteristics.

• 생명과학회지
• /
• 제25권7호
• /
• pp.740-747
• /
• 2015

본 연구는 150일간 냉동저장기간 중 재래흑돼지 등심과 뒷다리살의 품질변화와 항산화 특성을 알아보고자 실시하였다. pH 분석결과 등심의 경우 저장기간 동안 유의적으로 감소하였으나(p<0.05), 뒷다리살은 일관된 경향을 보이지 않았다. 등심의 경우 L*값은 저장1일부터 120일 동안 유의적인 차이를 보이지 않았으나 뒷다리살의 경우 저장기간에 따라 유의적으로 감소하였다(p<0.05). a*값의 경우 등심과 뒷다리살 모두 저장기간이 경과함에 따라 유의적으로 감소하였으며, b*값은 유의적으로 증가하였다(p<0.05). 보수력 지수는 등심의 경우 저장 1일 32.80%에서 30일에 유의적으로 감소하여(p<0.05) 저장 150일까지 26.42%로 유지됨을 나타내었다. 등심과 뒷다리살의 총균수는 각각 4.88, 5.16 Log CFU/g을 나타내었고, 저장 30일에 유의적으로 감소하였다(p<0.05). 냉동 저장 중 재래흑돼지 등심과 뒷다리살 각각의 2-thiobarbituric acid reaction substance 값은 0.057-0.069, 0.052-0.087 mg MDA/kg meat의 범위를 보였으나, 저장 150일까지 유의적인 차이는 없었다. 등심과 뒷다리살의 volatile basic nitrogen값은 각각 15.13-16.55, 16.05-16.23 mg%의 범위를 나타내었다. 등심과 뒷다리살의 항산화 활성인 oxygen radical absorbance capacity과 carnosine함량을 분석한 결과 냉동저장 150일 동안 유의적으로 감소하였다(p<0.05). 본 연구 결과, 재래흑돼지 등심과 뒷다리살의 냉동저장 중 식육의 품질은 다소 감소하는 경향은 있었지만 큰 변화는 없었다. 하지만, 항산화 활성과 항산화 기능을 갖는 di-peptide인 carnosine은 냉동저장 150일 동안 유의적으로 감소하였음을 나타내었다(p<0.05).

• Applied Biological Chemistry
• /
• 제24권2호
• /
• pp.85-93
• /
• 1981

섬유소(纖維素)를 이용(利用)하기 위한 기초연구(基礎硏究)로서 섬유소분해능(纖維素分解能)이 우수(優秀)한 균주(菌株)를 분리(分離)하여 동정(同定)한 결과(結果) Trichoderma spp.로 추정하였으며 사용된 섬유소 기질(基質)은 볏짚을 용제(溶劑)로 전처리(前處理)한 것과 여기에 산, 가열처리(加熱處理)를 더 가(加)한 것을 사용(使用)하였으며 이 미생물(微生物)에 의(依)하여 전처리 및 산 가열처리(加熱處理)에서 생성되는 섬유소 분해 효소(酵素)를 시험한 결과(結果) 0.1% $H_2SO_4$, $120^{\circ}C$, 한시간동안 처리한 것을 기질(基質)로 하였을 때 효소활성(酵素活性)이 높았다. 또한 pH 5.0, 5일(日) 배양(培養)에서 효소활성(酵素活性)이 증가(增加)하였으며 요소첨가시 20%. 인산칼륨첨가시 21%, 육류추출물첨가시 25%, 감귤피첨가시 19%의 증가(增加)를 나타냈다. 48시간(時間) 효소반응(酵素反應)을 시켰을 때 전처리기질(前處理基質)보다 산(酸), 가열처리기질(加熱處理基質)이 효소활성(酵素活性)이 높았으며 24시간후(時間後)에는 활성(活性)이 완만하였다.

• 한국식품영양과학회지
• /
• 제34권5호
• /
• pp.734-737
• /
• 2005

본 연구는 EM을 음수 및 사료내에 첨가하여 사양한 돼지의 육질개선 효과를 알아보기 위해 일반 돈육과 EM Pork의 이화학적 특성을 검토하고자 돼지 50두를 공시하여 일반성분, 육질 개선 및 육질 보존성에 관한 실험을 실시하였다. 콜레스테롤 함량 측정 결과, 일반 돈육은 평균적으로 $83{\pm}4mg/100\;g$ 이었는데 EM Pork는 $71{\pm}3\;mg/100\;g$을 나타내 유의적으로 낮은 함량을 보였다(p<0.05). 또한 TBA가는 저장기간 14일에 일반 돈육이 $0.184{\pm}0.003$ MDA mg/kg을 나타냈는데 EM Pork는 $0.165{\pm}0.004$ MDA mg/kg으로 처리구간 유의적인 차이를 나타내었다(p<0.05). VBN치는 일반 돈육을 5일간 냉동 저장한 것이 $3.72{\pm}0.05\;mg\%$이었고 EM Pork는 $3.2{\pm}0.05\;mg\%$를 나타냈으나 유의적인 차이는 보이지 않았다(p>0.05). 그러나 일반 돈육을 5일간 냉장 저장한 것은 $4.9{\pm}0.1\;mg\%$를 나타냈으나 EM Pork는 $3.19{\pm}0.04mg\%$를 나타내 일반 돈육보다 $35\%$ 정도 VBN치가 낮았으며 유의적인 차이를 나타냈다(p<0.05).

• 한국축산식품학회지
• /
• 제29권6호
• /
• pp.695-701
• /
• 2009

본 연구는 축산물가공장 작업환경에 설정된 CCP의 유효성을 평가하기 위하여, 원료도체에서부터 포장에 이르는 전 공정에서 Escherichia coli를 검출하고 PFGE genotyping으로 genetic strain의 흐름을 분석하여 CCP의 적합성을 평가하였다. 시료채취를 위한 작업장은 도축장에서 냉장차량으로 원료도체를 공급받는 독립형 소규모 HACCP 가공장(100두 처리/일)과 축산물종합처리장내 HACCP 가공장(500두 처리/일)을 각각 1곳씩 선정하였다. 시료는 원료도체, 시설 및 장비(발골기, 박피기, 작업대, 벨트, 칼, 면장갑), 환경(벽, 바닥)과 작업공정상의 발골육, 부분육, 최종육을 무균적으로 채취하였다. 작업공정에서 E. coli의 높은 분리율(59.6%)과 작업환경 전반에서의 고른 검출로 E. coli가 축산물가공장 위생지표균으로의 활용 가능성을 확인할 수 있었다. 분리된 E. coli의 genotype 분포는 작업장내 미생물 오염의 흐름을 보여주었다. 소규모가공장의 경우 오염된 원료육 반입이 작업공정을 오염시키고 공정중의 교차오염 발생으로 최종육에 영향을 주었고, 축산물종합처리장내 작업장은 원료육 오염보다는 작업환경에 상존하는 오염미생물의 교차오염이 최종육에 영향을 주는 양상이었다. 따라서 포장육가공장과 같이 작업공정에 멸균처리 과정이 없는 경우는 선행요건에 해당되는 원료반입과 작업환경의 세척 및 소독이 CCP로 관리되거나 이에 준하는 특별관리가 필요하였다. 결과적으로, 작업공정에서의 E. coli 검출과 genotyping은 작업공정상의 미생물 오염의 흐름을 파악하는데 유용하였으며, 이러한 방법은 HACCP 작업장의 미생물 오염원 분석과 설정된 생물학적 critical control point의 적합성 평가에 효과적이었다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제17권10호
• /
• pp.1472-1478
• /
• 2004

The effects of microorganisms inoculated in beef, pork and chicken on the production of various biogenic amines (BA) were examined. Acinetobacter haemolyticus, Aeromonas hydrophila subsp. hydrophila, Alcaligenes faecalis subsp. faecalis, Bacillus cereus, Bacillus subtilis, Enterobacter aerogenes, Enterobacter cloacae, Escherichia coli, Lactobacillus alimentarius, Lactobacillus curvatus, Leuconostoc mesenteroides subsp. Mesenteroides, Proteus mirabilis, Proteus vulgaris, Pseudomonas aerugina, Salmonella enteritidis and Salmonella typhimurium were inoculated into beef, pork and chicken and incubated for 24 h at optimum temperatures of each bacterium. In ground beef, total amount of amines (TAA) produced was highest in the sample inoculated with Bacillus cereus, followed by Enterobacter cloacae. In ground pork, TAA was highest in the sample inoculated with Alcaligenes faecalis, followed by Enterobacter cloacae, Proteus vulgaris and Bacillus cereus. TAA of chicken breast was highest in the sample inoculated with Alcaligenes faecalis, followed by Bacillus cereus and Lactobacillus alimentarius while in chicken leg was the sample inoculated with Proteus vulgaris, followed by Enterobacter aerogenes, Enterobacter cloacae and Alcaligenes faecalis. Among biogenic amines produced, cadaverine (CAD) was detected at the highest level, followed by putrescine (PUT) and tyramine (TYM), their order being reversed by the kind of microorganism in beef and pork. In chicken breast and leg, CAD level was still the highest but PUT, TYM or PHM was the second highest, depending upon the kind of microorganism inoculated. In total, Alcaligenes faecalis, Enterobacter cloacae and Bacillus cereus were ones that produced a larger amount of BAs regardless of meat sources from different species.

• 한국축산식품학회지
• /
• 제40권4호
• /
• pp.512-526
• /
• 2020

Synthetic nitrite is considered an undesirable preservative for meat products; thus, controlling synthetic nitrite concentrations is important from the standpoint of food safety. We investigated 1,000 species of microorganisms from various kimchi preparations for their potential use as a starter culture for the production of nitrites. We used 16S rRNA gene sequence analysis to select a starter culture with excellent nitrite and nitric oxide productivity, which we subsequently identified as Staphylococcus hominis subspecies hominis WiKim0113. That starter culture was grown in NaCl (up to 9%; w/v) at 10℃-40℃; its optimum growth was observed at 30℃ at pH 4.0-10.0. It exhibited nonproteolytic activity and antibacterial activity against Clostridium perfringens, a bacterium that causes food poisoning symptoms. Analysis of Staphylococcus hominis subspecies hominis WiKim0113 with an API ZYM system did not reveal the presence of β-glucuronidase, and tests of the starter culture on 5% (v/v) sheep blood agar showed no hemolytic activity. Our results demonstrated the remarkable stability of coagulase-negative Staphylococcus hominis subspecies hominis WiKim0113, especially in strain negative for staphylococcal enterotoxins and sensitive to clinically relevant antibiotics. Moreover, Staphylococcus hominis subspecies hominis WiKim0113 exhibited a 45.5% conversion rate of nitrate to nitrite, with nitrate levels reduced to 25% after 36 h of culturing in the minimal medium supplemented with nitrate (200 ppm). The results clearly demonstrated the safety and utility of Staphylococcus hominis subspecies hominis WiKim0113, and therefore its suitability as a starter culture.

• Journal of Applied Biological Chemistry
• /
• 제58권4호
• /
• pp.369-375
• /
• 2015

Meat from black pigs (BP) is in high demand compared with that from modern white pig (WP) breeds such as Landrace pigs owing to its high quality. However, the growth rate of black pigs is slower than that of white pig breeds. We investigated differences in the fecal microbial composition between white and black pigs to explore whether these breeds differed in the composition of their gut microbial communities. The swine gut microbiota was investigated using Illumina's MiSeq-based sequencing technology by targeting the V4 region of the 16S rRNA gene. Our results showed that the composition of the gut microbiota was significantly different between the two pig breeds. While the composition of the WP microbiota shifted according to the growth stage, fewer shifts in composition were observed for the BP gut microbiota. In addition, the WP gut microbiota showed a higher Firmicutes/Bacteroidetes ratio compared with that of BP. A high ratio between these phyla was previously reported as an obesity-linked microbiota composition. Moreover, the WP microbiota contained a significantly higher abundance of cellulolytic bacteria, suggesting a possibility of higher fiber digestion efficiency in WP compared to BP. These findings may be important factors affecting growth performance and energy-harvesting capacities in pigs. Our findings of differences in the gut microbiota composition between the two breeds may provide new leads to understand growth rate variation across pig breeds.