This study aimed to investigate the effect of Liriope platyphylla and organic acids on enteric methane mitigation in goats using an open-circuit simplified respiration chamber system. Methane recovery was evaluated by injecting 3% standard methane gas for 30 min at 3 L/min. The percentage of methane recovery from the four chambers was 99±5.4%. Following the recovery test, an animal experiment was conducted using eight castrated Boer goats (body weight 46.6±7.77 kg) using a 2×2 crossover design. Experimental diets were as follows: 1) Control (CON), commercial concentrate and tall fescue, and 2) Treatment (MIX), concentrate supplemented with L. platyphylla and organic acids and tall fescue. Goats were offered feed at 2% of body weight (dry matter basis) in equal portions twice daily at 8:00 and 15:30. The goats were adapted to the feed and methane chamber for 10 and 3 days, respectively. Methane emission was measured one day per goat using tunable diode laser absorption spectroscopy, and temperature and airflow measurements were used to estimate methane emissions. Dry matter intake (DMI), body weight, and methane emission were measured during each period. Methane production with CON and MIX was 24.48 and 22.68 g/d, respectively, and 26.81 and 24.83 g/kg DMI, respectively. Although the differences were not significant, the use of supplements resulted in a numerical reduction in methane in MIX compared with CON. Collaboration with experts in other areas, including various engineering departments, is imperative to measure methane emissions using a chamber system accurately.

Livestock production costs are heavily influenced by the cost of feed, The use of domestically grown forages is more desirable for livestock feed production. As part of this study, triticale, which is an extremely palatable and easily cultivable crop in Korea, was used to produce low moisture silage bales with lactic acid bacteria (LAB) and then stored for different periods. We examined the nutrient content of silage, such as crude protein (CP), acid detergent fiber (ADF) and neutral detergent fiber (NDF), as well as their organic acids, including lactic acid, acetic acid, butyric acid, at different storage periods. The nutrient content of silages, such as crude protein, ADF, and NDF, did not change significantly throughout storage periods. Organic acid data indicated that lactic acid concentrations increased with increasing moisture contents and storage periods up to nine months. However, further extending storage to 12 months resulted in a reduction in the lactic acid content of all silages as well as an increase in their pH. Based on the present results, it suggested that the production of low moisture silage with the LAB may be able to preserve and maintain its quality without altering its nutritional composition. Also, the lactate content of the silage remained significant for at least nine months.

Biomass porous carbons derived from Laminaria japonica were prepared by KOH and H3PO4 activation methods, respectively. The results indicated that the chemical activation had an apparent effect on the molecular framework and space of materials. To enhance the selective adsorption for organic acids, biomass carbons were modified by dopamine combined with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane. The SEM and BET results illustrated the effect of the chemical activation approach on the morphology and porous texture. The biomass porous carbon using KOH activation method had the highest surface area (up to 1558 m2/ g). Compared with unmodified materials, the modified materials showed higher adsorption capacity for organic acids (27.90 μg/mL for chlorogenic acid and 25.47 μg/mL for caffeic acid). It was suggested that modification of porous carbons might be a viable pathway to increase the specific adsorption affinity and efficiency for organic acids in dried jujube samples.

본 연구는 수출 팽이버섯에서 L. monocytogenes가 검출되어 리콜 됨에 따라 팽이버섯의 안전성을 확보하기 위하여 유통 온도에 따른 팽이버섯 중 L. monocytogenes의 생존을 조사하고 유기산을 이용한 팽이버섯 중 L. monocytogenes 의 저감화 기술을 개발하였다. 저장 온도에 따른 팽이 버섯 중 L. monocytogenes의 생존을 조사하기 위하여 L. monocytogenes가 오염된 팽이버섯(초기 농도 4.5 Log CFU/g)을 1-35 ̊C에 각각 저장하고 균수변화를 조사하였다. 그 결과 팽이버섯을 1 ̊C에 저장하였을 때 L. monocytogenes 는 1개월 내에 증식하지 않았고 30 ̊C, 35 ̊C에서는 각각 36시간, 24시간이내에 3.0 log CFU/g 증가하였다. 팽이버섯 중 L. monocytogenes의 저감화를 위하여 1-3% 유기산 3종 (초산, 젖산, 말산)에 10-30분 동안 처리하였을 때 팽이버섯 중 L. monocytogenes는 초산보다는 말산, 젖산의 저감효과가 높았고 젖산과 말산의 처리 농도가 증가할수록 저감효과는 증가하는 것으로 나타났다. 3% 젖산과 말산을 10분 이상 처리하면 약 3.0 log CFU/g이상 감소하였다. 따라서 팽이버섯의 안전성을 확보하기 위해서는 수출할 때는 1 ̊C 내외의 저온을 유지하고 소비단계에서는 3% 젖산과 말산에서 10분 정도 처리 후 섭취하는 것이 필요하다.

비육돈사의 슬러리에 함유된 악취물질의 농도를 계절별로 비교하여 초지 및 농경지에 살포되는 분뇨의 악취강도를 예측하고자 수행되었다. 1.비육돈사의 슬러리에 함유된 휘발성유기물의 계절별 농도 비교페놀류 중 p-크레졸 농도는 봄, 여름 및 가을에 차이가 없었지만, 페놀, 인돌 및 스카톨 농도는 여름과 가을에 비해 봄에 높았다(p<0.05). 돼지 슬러리의 경우 p-크레졸과 스카톨이 악취강도에 큰 영향을 주기 때문에 계절에 따른 휘발성유기물의 악취강도 차이는 크지 않을 것으로 판단된다. 2.비육돈사의 슬러리에 함유된 휘발성지방산의 계절별 농도 비교휘발성지방산의 경우 악취강도가 높지 않은 단쇄지방산의 농도는 봄철이 여름과 가을보다 높았으나(p<0.05), 악취강도가 상대적으로 높은 이성체지방산의 농도는 계절별로 숫자적인 차이는 보였지만 통계적인 차이는 없었다(p> 0.05). 계절에 따라 휘발성지방산이 악취강도에 미치는 영향은 높지 않을 것으로 판단된다. 결과적으로 봄철에 악취물질의 농도가 더 높은 것은 온도, 환기 및 돈사내부로 유입되는 물의 양에 의한 것으로 추정되며, 여름철은 슬러리에서 생성되는 악취농도 보다 환기에 의해 휘산되는 양이 많아서 슬러리의 악취농도가 감소되거나 증가되지 않았을 가능성이 있는 것으로 판단된다. 이상의 연구결과를 종합하면 비육돈사의 슬러리를 초지 또는 농경지에 살포하였을 때 계절에 의한 악취강도의 차이는 크지 않을 것으로 기대된다.

본 연구는 사일리지 발효 특성에 있어 미생물제제와 유기산제제의 처리효과를 분석하고 비교하기 위한 목적으로 수행되었다. 사일리지 pH, 젖산, 초산, L/A비율, 프로피온산, 낙산, WSC, CP, NH3-N, NDF 및 ADF 등을 발효 특성 항목으로 조사하였고, 메타분석기술을 이용하여 분석을 수행하였다. 총 14편의 연구논문들을 분석에 사용하였다. 미생물제제 처리는 대조구에 비하여 pH, 젖산, 초산, L/A 비율, 프로피온산 및 ADF 함량 향상시키는 것으로 나타났다(p<0.01). 이와는 반대로 낙산, WSC, CP, NH3-N 및 NDF는 대조구에 비하여 감소하는 것으로 나타났다(p<0.001). 유기산제제의 처리는 ADF 결과를 제외하고 모든 조사 항목에서 대조구에 비해 처리구에서 높은 결과를 갖는 것으로 나타났다(p<0.001). 미생물제제와 유기산제제의 처리효과 비교에서 유의적인 차이는 낙산, WSC, CP 및 NH3-N에서 나타났고(p<0.05), 미생물제제 처리가 유기산제제 처리에 비하여 낙산, WSC, CP 및 NH3-N 함량을 낮추는 것으로 나타났다(p<0.05).

신선편의 샐러드와 유기농 채소에 오염되어 있는 식중독균인 B. cereus, S. aureus 그리고 E. coli를 대상으로 살균 소독제와 유기산에 대한 감수성을 평가하여 신선편의 식품의 미생물학적 안전성의 확보를 위한 올바른 세척제와 사용량을 제시하고자 하였다. S. aureus는 2% acetic acid, malic acid, tartaric acid와 1% CaO에 대하여 고농도의 염소계, 과산화수소계 보다 높은 살균 효과를 보였고 E. coli의 경우에는 1% acetic acid 와 CaO처리에 의해 80%의 분리주가 감소하여 50%에탄올과 400 ppm 차아염소산나트륨과 대등한 감소율을 보였다. B. cereus 분리주에 대한 1% CaO, 0.5% acetic acid, 2% malic acid와 tartaric acid 처리는 200 ppm의 차아염소산나트륨보다 높은 감소율을 나타내었고, 1%의 과산화수소와 대등한 감소율을 나타내었다. 본 연구에 따라 천연 물질 유래 살균 소독제인 CaO와 유기산은 기존의 화학적 살균제를 대체할 수 있는 천연 살균 소독제로 활용 될 수 있을 것이고 특히 환경 친화적이고 안전한 유기산은 고품질의 신선편의 채소를 안전성으로 공급하는데 효과적인 것으로 판단되었다.

발효공정으로부터 생산된 유기산의 회수를 위하여 나노여과 분리막 공정을 이용하는 경우 유기산을 제외한 발효 액 내 존재하는 당, 단백질 등의 부산물을 배제하면서 유기산을 선택적으로 투과시킬 수 있는 나노여과막이 요구된다. 본 연 구에서는 발효액으로부터 분자량이 상대적으로 작고 카르복실산기를 갖는 유기산의 효과적인 회수를 위하여 분리막 표면에 양전하를 도입하여 전기적 인력에 의해 젖산의 투과도를 향상시킬 수 있는 신규 나노여과 분리막을 제조하였다. 분리막 표면에 고분자 전해질 PEI (Polyethyleneimine)를 그라프팅시켜 제조된 분리막의 제타전위 측정 결과 표면 층이 양전하를 나타내 는 것을 확인하였다. 실제 젖산 용액 배제율 확인 결과 고분자 전해질 그라프팅 층이 형성된 막에서 배제율이 크게 감소하는 것으로 보아 그라프팅 층에 의한 젖산 배제율 저감에 효과를 나타내었다.

The purpose of this study is to evaluate antimicrobial effects of organic acid and some natural occurring antimicrobials against Staphylococcus aureus isolated from various origins (vegetables, peanut, pea leaf, kim- bab, person, perilla leaf, and animal) and to calculate their MIC and MBC values. Five organic acids (acetic, lactic, citric, malic, and propionic acid), three essential oils (carvacrol, thymol, and eugenol), and two other natural antimicrobials (nisin and cinnamic acid) were evaluated for their antimicrobial effects against 113 strains of S. aureus using combination treatments. Propionic acid (7%), nisin (1%), thymol (1%), carvacrol (1%) showed antimicrobial activities against S. aureus strains in agar disc diffusion test. And, carvacrol, thymol, and nisin were found to be the most effective with the lowest MIC values of 0.0313%, 0.0625%, and 0.0625% against S.aureus, respectively. Propionic acid (0.2313%) and citric acid (0.6000%) were the most effective among organic acids tested. Therefore, these five antimicrobials were selected for next combination treatments. Combination of propionic acid and citric acid were showed the strongest inhibitory effectiveness against S. aureus among combination treatments. These results suggest that organic acid such as propionic and citric acid, and natural occurring antimicrobial such as nisin, carvacrol, and thymol might be possibly used as preservatives for inhibiting S. aureus in foods.

This study was performed to compared the effectiveness of individual treatments (electrolyzed water: EW, organic acid, and ultrasound) and their combination on reducing foodborne pathogens from perilla leaves. Perilla leaves were innoculated with a cocktail of Salmonella Typhimurium, Staphylococcus aureus, Bacillus cereus. Inoculated perilla leaves were treated with EW combined with different concentration of acetic acid (0.5%, 1.0%, 1.5%, 2.0%) for 1 min at room temperature. Treatment of 3 pathogens on perilla leaves with electrolyzed water combined with ultrasound (25 kHz) and 0.5% acetic acid was also performed for 1 min. While the numbers of S. Typhimurium and B. cereus showed reduced with increasing acetic acid concentration, there is no difference in the number of S. aureus treated with EW containing 0.5% to 1.5% acetic acid. Discoloration was observed the perilla leaves treated with EW combined with more than 1.0% acetic acid. For all three pathogens, the combined treatment of EW and ultrasound resulted in additional 0.42 to 0.72 log10 CFU/g. The maxium reductions of S. Typhimurium and B. cereus were 0.95, 1.23 log10 CFU/g after treatment with EW combined with 0.5% acetic acid and ultrasound simultaneously. The results suggest that the treatment of EW combined with 0.5% acetic acid and ultrasound increased pathogens reduction compared to individual treatment.

This study was conducted to investigate of changes for organic acids in takju during storage conditions. Two types of takju, unsterilized and sterilized, were used. Acetic acid, citric acid, lactic acid, malic acid and succinic acid were detected in sample. Residues of malic acid was not detected after 7 days storage in room temperature( 25oC). In contrast to lactic acid was increased by times after storage. Acetic acid concentrations was gradually increased in room temperature but was not changed in cold temperature(4oC). After storage for 10 days, the organic acid residues lactic acid > citric acid > succinic acid > malic acid > acetic acid in unsterilized takju. Compared to unsterilized sample, organic acid residues in sterilized sample was not significantly changed. Consequently, organic acids residues mainly affected by sterilization.

Although bacterial outbreaks from ready-to-eat foods such as sprouts have increased, the information on microbial biocontrol by means of sanitizers is limited. Twenty sprouts of red cabbage, baby radish, alfalfa, and broccoli each were collected from the wholesale markets in Seoul. Ethanol and organic acids including acetic acid, citric acid, and lactic acid were used to control the amount of mesophilic bacteria and Bacillus cereus. Sanitizer mixtures of ethanol and organic acids showed a remarkable reduction of viable counts and, in particular, the sanitizer mixture comprised of 20% ethanol and 1% lactic acid seemed to be best by a reduction of 7～8 log CFU/g on the sprouts after a 10 minute exposure. At the same time, the sanitizer comprised of 20% ethanol and 1% lactic acid showed the same reduction for Escherichia coli, Salmonella typhimurium, B. cereus, Staphylococcus aureus, and Enterococcus faecalis, with more effect toward the Gram-negative bacteria. Sensory evaluation by texture, browning, off-flavour, and overall acceptability seemed better just after treatment when compared to one day after treatment with the sanitizer. Therefore, the sanitizers of ethanol-organic acid might be an effective means to control the bacterial contamination of sprouts in palce of sodium hypochloric acid.

This study was carried out to investigate efficacy of aerosol sanitizer with natural antimicrobial and organic acids against Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes. The artificially inoculated pathogens on stainless steel coupon were treated with grapefruit seed extract (GFE), acetic acid,citric acid and lactic acid in model cabinet for 5 min. The number of three foodborne pathogens with individual treatment was reduced by 0.34-3.77 log units, treatment with GEF + organic acid was reduced by 1.72-3.89 log units and treatment with GEF + organic acid + alcohol was reduced by 1.46-5.05 log units. By treatment with GEF + lactic acid + alcohol in scale-up model system for 10 min. Populations of E. coli O157:H7, S. Typhimurium and L. monocytogenes were reduced by 3.42, 2.72 and 2.30 log units from the untreated control respectively. From the above result,aerosol sanitizer with natural antimicrobial agents and organic acid can be used as an environmental sanitation method with satisfying the consumer demand on safe food.