• 한국식품과학회지
• /
• 제45권5호
• /
• pp.590-597
• /
• 2013

고전압 펄스 전기장 기술은 가열 공정을 대체할 수 있는 비가열 살균기술로서 꾸준한 연구가 이루어지고 있는 기술이다. 본 실험에서는 미생물의 생리적 측면에서 고전압 펄스 전기장 처리에 의한 효모의 생리적 변화를 살펴보았다. 내염성의 변화를 측정한 결과 사멸하지 않은 세포의 90-99% 이상이 세포 손상에 의해 내염성을 소실하였으며, 내염성을 회복하는데 약 4-6시간의 시간이 걸렸다. 고전압 펄스 전기장 처리 초기에는 세포 내외의 pH 구배(${\Delta}pH$)가 차이가 컸으나 처리시간이 증가함에 따라 그 차이가 감소하였다. 이는 세포의 pH 항상성을 유지시키는 $H^+$-traslocation 기능을 담당하고 있는 $H^+$-ATPase 활성이 소실되었거나 세포막 자체가 손상되어 pH 항상성을 잃어버렸기 때문으로, 이는 고전압 펄스 전기장 처리한 세포의 $H^+$-ATPase의 활성이 초기부터 크게 감소하는 것으로 확인할 수 있었다. 또한 세포의 해당활성이 고전압 펄스 전기장 처리에 의해 크게 감소하여 세포의 대사 기능이 손상되는 것을 확인하였다.

• 한국식품과학회지
• /
• 제46권6호
• /
• pp.778-781
• /
• 2014

비가열 살균 기술의 하나인 광펄스 기술을 이용하여 마른 김에 존재하는 미생물에 대한 살균 효과와 품질 변화에 대하여 알아보았다. 마른 김에 1,000 V, 5 pps의 조건하에서 7.9 cm의 거리에서 광펄스 조사를 하였을 때 처리 1분 후에는 0.6 log CFU/g, 처리 10분 후에는 1.6 log CFU/g의 사멸 효과를 보였다. 같은 조건에서 광펄스 조사 후 마른 김의 표면 온도는 약 $1.9^{\circ}C$의 상승을 나타냈으며, 색도에 있어서는 명도가 증가하고, 적색도 및 황색도는 감소하는 경향을 보였으며, 처리 시간이 길어질수록 전체적인 색도의 차이가 크게 나타나는 결과를 보였으나 육안으로는 차이 정도를 확인할 수 없었다. 이러한 결과로 미루어 볼 때 광펄스 살균 기술은 품질 변화없이 마른 김에 존재하는 위해 미생물을 효과적으로 감소시킬 수 있을 것으로 판단된다.

• 한국축산식품학회지
• /
• 제39권6호
• /
• pp.863-876
• /
• 2019

The thermal-death times of Listeria monocytogenes were determined in inoculated restructured goat steak at 60℃, 65℃, and 70℃ of sous-vide temperatures. D-values of L. monocytogenes in inoculated restructured goat steak ranged from 7.27 min at 60℃ to 0.46 min at 70℃. Times need to yield at least a 6 log reduction of L. monocytogenes at their temperatures for this product were 47, 12, and 3 min, respectively. After sous-vide, all microbial counts in non-inoculated samples were not detectable, except the aerobic and anaerobic mesophilie and lactic acid bacteria counts were lower than 2 Log CFU/g. For sous-vided and grilled sous-vided samples, sous-vide loss and surface shrinkage were the lowest in samples sous-vided at 60℃ for 47 min (p<0.05). These samples demonstrated the lowest CIE L^*, shear force, hardness, gumminess and chewiness and the highest CIE a^* and hue angle (p<0.05). Therefore, sous-vide at 60℃ for 47 min provided convenient ready-to-cook restructured goat steak for microbiology safety and optimization of physicochemical quality.

• 한국축산식품학회지
• /
• 제32권5호
• /
• pp.561-570
• /
• 2012

The objective of this study was to evaluate the effects of an atmospheric pressure plasma (APP) jet on L. monocytogenes inactivation, quality characteristics, and genotoxicological safety of cooked egg white and yolk. APP treatment using He gas resulted in a 5 decimal reduction in the number of L. monocytogenes in cooked egg white, whereas that using $He+O_2$, $N_2$, and $N_2+O_2$ decreased the number further, and to undetectable levels. All treatments of cooked egg yolk resulted in undetectable levels of inoculated L. monocytogenes. There were no viable cells of total aerobic bacteria after APP treatment on day 0 while the control showed approximately 3-4 Log CFU/g. On day 7, the numbers of total aerobic bacteria had increased by approximately 3 log cycles in cooked egg white, but there were no viable cells in cooked egg yolk after 2 min of APP jet. APP treatment decreased the $L^*$-values of cooked egg white and yolk significantly on day 0. No significant sensory differences were found among the cooked egg white samples, whereas significant reductions in flavor, taste, and overall acceptability were found in cooked egg yolks treated with APP jets. SOS chromotest did not reveal the presence of genotoxic products following APP treatments of cooked egg white and yolk. Therefore, it can be concluded that APP jets can be used as a non-thermal means to enhance the safety and extend the shelf-life of cooked egg white and yolk.

• Food Science and Biotechnology
• /
• 제18권5호
• /
• pp.1132-1137
• /
• 2009

Successive application of Saccharomyces cerevisiae DSM 70424 and Saccharomyces rouxii DSM 2535 or DSM 2531 in the production of non-alcoholic beer was investigated. The aim of the study was to consider the impact of the 2 mentioned strains of S. rouxii on the reduction of alcohol content in wort fermented at 12 or $24^{\circ}C$ for 96 hr, applying periodic aeration. The 2 S. rouxii strains were added at the $48^{th}$ hr of fermentation after thermal inactivation of S. cerevisiae cells. The greatest alcohol decrease rate was observed for the treatment containing S. rouxii DSM 2535-fermented at $24^{\circ}C$ (from 1.56 to 0.36%). The concentration of acetaldehyde, diacetyl, and 2,3-pentandione, that have a key role in appearance of 'wort' and 'buttery' off flavors, were significantly lower in S. rouxii-containing treatments fermented at $24^{\circ}C$. S. rouxii-containing treatment fermented at $24^{\circ}C$ showed slightly lower overall flavor acceptability compared to S. cerevisiae-containing treatment fermented at the same temperature. Such score was improved for the products obtained at $12^{\circ}C$.

• 한국수산과학회지
• /
• 제54권1호
• /
• pp.16-22
• /
• 2021

This study investigated the reduction in human norovirus (HNV) GII. 4 count in pacific oyster Crassostrea gigas using electron beam irradiation. Infectious HNV GII. 4 was detected using RT-qPCR (real time reverse transcription-quantitative polymerase chain reaction) with PMA (propidium monoazide)/sarkosyl. At electron beam doses 1, 5, 7, and 10 kGy, the count of HNV GII. 4 was 2.74, 2.37, 2.06, and 1.55 log copies/μL (control, 3.01 log copy/μL), respectively, confirming that as the irradiation dose increased, norovirus count reduced significantly (P<0.05). After PMA/sarkosyl treatment, the counts further reduced at the same irradiation dose, and 10 kGy showed significant differences between the non-treated and PMA/sarkosyl-treated samples (P<0.05). The Ed (decimal reduction dose of electron beam) value based on the first-order kinetic model was 7.33 kGy (R2=0.98). No significant difference was observed in the pH values of the control (6.2) and electron beam-irradiated samples at all doses (6.1). For sensory evaluation, the non-treated sample scored the highest in all categories (5.25-6.17), while the samples treated with 10 kGy showed the lowest score (4.67-5.33), although without statistical significance (P>0.05). Overall, our results suggest that 7 kGy electron beam is sufficient for the non-thermal sterilization of oysters without causing significant changes in quality.

• 한국축산식품학회지
• /
• 제44권2호
• /
• pp.239-254
• /
• 2024

This review sought to categorize studies on meat tenderization and safety through pulsed electric field (PEF) treatment, with a particular focus on reconciling conflicting findings regarding the tenderization effect (i.e., the primary outcome of PEF treatment) and to discuss the underlying mechanisms of these effects. While the tenderization effect may vary depending on the homogeneity of PEF treatment and variations in the conditions of texture measurements, the protein associated with tenderization was degraded by PEF treatment in most studies. PEF technology enables the delivery of a high voltage for a brief duration, typically in the microsecond range, making it a non-thermal technology. One of the distinct advantages of PEF is its ability to preserve the freshness of meat due to its exceptionally short treatment time. While PEF studies have traditionally centered on pasteurizing liquid foods, research on its application to meat is steadily expanding. Therefore, this review aims to elucidate the mechanisms of PEF and provide current insights into the applications of this technology for meat tenderization and microbial inactivation.

• 한국축산식품학회지
• /
• 제44권2호
• /
• pp.309-325
• /
• 2024

The consumption of meat has been increasing, leading to a dynamic meat and meat processing industry. To maintain the quality and safety of meat products, various technologies have been explored, including intense pulsed light (IPL) technology. Several factors affect the inactivation of microorganisms by IPL treatment, including light intensity (fluence), treatment duration, pulse frequency, and the distance between the lamp and the samples. Meat products have been studied for IPL treatment, resulting in microbial reductions of approximately 0.4-2.4 Log. There are also impacts on color, sensory attributes, and physico-chemical quality, depending on treatment conditions. Processed meat products like sausages and ham have shown microbial reductions of around 0.1-4 Log with IPL treatment. IPL treatment has minimal impact on color and lipid oxidation in these products. Egg products and dairy items can also benefit from IPL treatment, achieving microbial reductions of around 1-7.8 Log. The effect on product quality varies depending on the treatment conditions. IPL technology has shown promise in enhancing the safety and quality of various food products, including meat, processed meat, egg products, and dairy items. However, the research results on animal-based food are not diverse and fragmentary, this study discusses the future research direction and industrial application through a review of these researches.

• 한국식품과학회지
• /
• 제31권6호
• /
• pp.1577-1582
• /
• 1999

자체 제작한 고전압 펄스 전기장 장치를 이용하여 당근주스의 주요 변패 미생물인 대장균(Escherichia coli)의 불활성에 미치는 전기장 세기, 처리시간, 온도 등을 관찰하고 품질변화에 관하여 연구하였다. E. coli의 불활성에 필요한 최소 전기장세기인 임계전기장 세기(Ec)는 11.74 kV/cm, 최소처리시간(tc)는 $3.6{\mu}s$이었다. 사멸효과는 전기장의 세기가 클수록, 처리시간이 길수록 그리고 처리온도가 높을수록 증가하였다. 당근주스의 pH, 가용성 고형분 $(^{\circ}Brix)$, 적정산도는 거의 변화가 없었다. 색도는 50^{\circ}$ 열병합 PEF처리 주스만이 약간 감소하는 경향을 보였지만 다른 처리구들은 변화가 거의 없었다. ${\alpha},\;{\beta}-carotene$의 함량도 거의 변화가 없었다.

• 한국식품영양과학회지
• /
• 제40권1호
• /
• pp.123-127
• /
• 2011

김치 제조 공정에서 사용되는 김치 절임수의 미생물학적 안전성 확보와 재활용을 위한 연구로써, 본 연구에서는 microwave plasma sterilization system을 이용한 김치 절임수의 미생물 수 저감화를 위하여, E. coli O157:H7, L. monocytogenes, S. Typhimurium에 대한 살균 효과를 측정하고, 또한 사용한 김치 절임수에 본 장치를 적용하였다. 김치 공장에서 반복 사용한 절임수에 있는 coliform, E. coli, Salmonella spp., total aerobic bacteria, yeasts and molds가 사용 횟수가 늘어남에 따라 미생물 수가 증가하였다. Microwave plasma를 이용한 살균처리에서는 E. coli O157:H7, L. monocytogenes, S. Typhimurium의 $D_{10}$-value가 0.48, 0.52, 0.45 cycle로 각각 측정되었고, 또한 1회 사용한 절임수에 microwave plasma sterilization system 적용 시, coliform, E. coli, Salmonella spp., total aerobic bacteria, yeasts and molds 숫자가 유의적으로 감소하였다. 따라서 본 연구 결과, 김치공장의 김치 절임수를 재사용하기 위해서 microwave plasma sterilization system을 이용한 살균방법이 적합하다고 판단된다.