• 한국식품과학회지
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• 제36권2호
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• pp.365-367
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• 2004

절임 배추의 저장 기간을 연장하기 위하여 배추를 절인 다음 전해산화수로 세척하고 저장하면서 품질 특성의 변화를 측정한 결과는 다음과 같았다. 즉 절임 배추를 전해산화수로 세척한 처리구가 대조구보다 낮은 pH를 보였으며, 저장 8일까지는 대조구에 비하여 낮은 pH를 나타내었다. 적정산도는 저장기간 동안 0.11-0.15%로 큰 변화를 나타내지 않았으며, 대도구와 처리구간에도 큰 차이가 없었다. 절임 배추를 전해산화수로 세척한 직후에는 대조구에 비하여 총균수가 $10^3\;CFU/mL$ 정도 낮았으나 처리구의 총균수는 저장 6일에 대조구와 비슷하였다. 유산균수도 세척 직후에는 처리구가 대조구보다 낮았으며, 저장 4일에는 대조구와 처리구의 차이가 가장 현저하였다. 저장 2일까지는 국물의 밝은 정도(L)에 있어서 대조구와 처리구간에 차이가 없었으나 그 이후에는 처리구가 대조구보다 높은 값을 나타내었다.

• 한국환경보건학회지
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• 제28권3호
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• pp.34-38
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• 2002

Statistical analysis between sewage plant operating parameters and the effluent quality was performed. We extracted two factors from principal component analysis of operating parameters and effluent quality from each plant. The total variance of 84.7%, 79.2% was explained by the two factors at SB plant and SC plant, respectively. The factors were identified at SB plant in the following order 1) the oxidation of organic material by aeration basin microbe,2) biomass in aeration basin and at SC plant 1) the oxidation of organic material by aeration basin microbe, 2) thickening of acti-vated sludge. These results suggested that the control of microbial composition might be critical on the improvement of the effluent quality and plant operating efficiency because most of the factors were related with microbes.

• 식품과학과 산업
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• 제50권2호
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• pp.12-26
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• 2017

Processing steps such as washing and cutting, involved in preparing fresh-cut produce causes tissue damage, leading to rapid quality deterioration. Major defects of fresh-cut produce are discoloration, softening, off-odor development, and microbial growth. Packaging of fresh-cut produce has been changed to reduce these quality problems. Flexible packaging film is widely used to pack fresh-cut produce. Vacuum packaging was the popular packaging method in the beginning of fresh-cut industry in Korea. Vacuum packaging creates high $CO_2$ and low $O_2$ levels to control browning of fresh-cut produce. However, these conditions induce some visual defects and off-odor development. Discoloration problem was also found when fresh-cut produce was packaged with conventional packaging film or plastic tray. Modified atmosphere (MA) packaging is effective for prolonging shelf-life of fresh-cut produce by decreasing $O_2$ and increasing $CO_2$ concentration in the package. Retail MA packaging using different oxygen transmission rate (OTR) film and micro-perforated film has started to be applied to fresh-cut produce in Korea. Proper MA package design that provides optimum range of $O_2$ and $CO_2$ partial pressures is one of the major challenges in the industry. An initial package flushing with $N_2$ or an low $O_2$/high $CO_2$ atmosphere is also used to more rapidly establish steady-state MA condition. Film OTR and $O_2$ flushing affects the fermentative volatile production, off-odor development, electrolyte leakage, discoloration, $CO_2$ injury, microbial population of fresh-cut produce. There is also a demand for convenient packaging to attract consumers. Rigid fresh-cut produce container for retail market has increased since the packaging provides excellent protection from physical damage during transport. Rigid tray used as actual serving vessel for the consumer is increasing in Korea. The tray with flexible lid to wrap or seal fresh-cut produce is more and more gaining popularity. Further practical technology to control quality change and microbial growth for each fresh-cut product has been studied since various fresh-cut items were required. The fresh-cut industry also focuses on searching for more convenient and environmentally friendly packaging.

• Animal Bioscience
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• 제37권1호
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• pp.84-94
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• 2024

Objective: The objective of this study was to investigate how cellulase or/and lactic acid bacteria (LAB) affected the fermentation characteristic and microbial community in wet brewer's grains (WBG) and corn stover (CS) mixed silage. Methods: The WBG was mixed thoroughly with the CS at 7:3 (w/w). Four treatment groups were studied: i) CON, no additives; ii) CEL, added cellulase (120 U/g fresh matter [FM]), iii) LAB, added LAB (2×10⁶ cfu/g FM), and iv) CLA, added cellulase (120 U/g FM) and LAB (2×10⁶ cfu/g FM). Results: All additive-treated groups showed higher fermentation quality over the 30 d ensiling period. As these groups exhibited higher (p<0.05) LAB counts and lactic acid (LA) content, along with lower pH value and ammonia-nitrogen (NH₃-N) content than the control. Specifically, cellulase-treated groups (CEL and CLA) showed lower (p<0.05) neutral detergent fiber and acid detergent fiber contents than other groups. All additives increased the abundance of beneficial bacteria (Firmicutes, Lactiplantibacillus, and Limosilactobacillus) while they decreased abundance of Proteobacteria and microbial diversity as well. Conclusion: The combined application of cellulase and LAB could effectively improve the fermentation quality and microbial community of the WBG and CS mixed silage.

• 한국유기농업학회지
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• 제23권3호
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• pp.523-534
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• 2015

본 연구는 미생물제제의 일종인 yeast culture 및 코팅 처리된 vitamin-C의 첨가 급여를 통해 비육 말기 Holstein 거세우의 증체 및 도체형질에 미치는 영향을 조사하기 위한 목적으로 실시하였다. 평균체중이 $714{\pm}13.60kg$인 18개월령 Holstein 거세우 24두를 공시동물로 이용하였으며 각각 8두씩 3개 시험구로(대조구, MC급여구, CVC급여구) 완전임의 배치하여 출하 전 3개월간 사양시험을 실시하였다. MC급여구는 yeast culture를 일일 30 g, 코팅 처리된 vitamin-C는 일일 10 g씩 매일 아침 사료급여 시 top dressing형태로 급여하였다. 일당증체량은 MC급여구가 가장 높았으며 사료요구율은 MC급여구와 CVC급여구에서 가장 낮았다. 등지방두께, 배체장근 및 육량은 시험구간 유의차가 없었다. 지육중량과 성숙도는 MC급여구에서 가장 높았으며, 지방색은 CVC급여구에서 가장 높게 나타났다. 이상의 결과를 종합해 보면 출하 3개월 전 Holstein 거세우에게 항생제 대체제로 미생물제제인 yeast culture 또는 코팅 처리된 vitamin-C의 급여는 육질에는 큰 효과가 없으나 육량, 지육중량, 사료요구율 등에 긍정적인 영향을 줄 수 있을 것으로 판단된다. 아울러 미생물제제와 vitamin-C를 함께 급여하면 더욱 좋은 효과가 있을 것으로 예상된다.

• 한국토양비료학회지
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• 제46권6호
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• pp.474-481
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• 2013

Understanding the microbial community structure of agricultural soils is important for better soil management in order to improve soil quality. Phospholipid fatty acid analysis has been popularly used in determining the microbial community structure in different ecosystems. The microbial community structure of paddy soil under long-term fertilizer treatments was investigated after 45 years using PLFA analysis. Treatments were control (no fertilization, Con), compost (COM), NPK, NPK+compost (NPKC), PK, NK, and NP. Soil chemical properties were mainly affected by the addition of compost and inorganic P fertilizer. Total nitrogen and organic matter contents were significantly higher in treatments with compost while available $P_2O_5$ and exchangeable calcium were significantly higher in treatments with added inorganic P fertilizer. It was found that microbial communities were responsive to the different fertilizer treatments. PLFA results showed that the soils were dominated by gram-negative bacteria, followed by the actinomycetes, then gram-positive bacteria, and fungi. Principal component analysis of the soil chemical properties and PLFA composition proved to be a more reliable tool because it was more responsive to the changes in soil chemical properties.

• 한국토양비료학회지
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• 제45권6호
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• pp.1073-1085
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• 2012

Soil microbial communities are immensely diverse and complex with respect to species richness and community size. These communities play essential roles in agricultural soil because they are responsible for most of the nutrient cycles in the soil and influence the plant diversity and productivity. However, the majority of these microbes remain uncharacterized because of poor culturability. Next-generation sequencing techniques have revolutionized many areas of biology by providing cheaper and faster alternatives to Sanger sequencing. Among them, amplicon pyrosequencing is a powerful tool developed by 454 Life Sciences for assessing the diversity of complex microbial communities by sequencing PCR products or amplicons. This review summarizes the current opinions in amplicon sequencing of soil microbial communities, and provides practical guidance and advice on sequence quality control, aligning, clustering, OTU- and taxon-based analysis. The last section of this article includes a few representative studies conducted using amplicon pyrosequencing.

• 동아시아식생활학회지
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• 제22권2호
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• pp.264-270
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• 2012

본 연구는 pectinase 처리가 레드와인 발효와 와인의 품질에 미치는 영향을 분석하였다. 실험군과 대조군으로 구분하여 진행하였으며, pectinase 처리가 와인제조 과정에서 과즙 추출 향상, 과즙 청징 작용으로 색의 투명성과 안정성에 좋은 효과를 나타냄을 확인할 수 있었다. 포도과즙 산출량 변화를 확인한 결과에서는 pectinase가 펙틴을 분해하여 약 13%(v/v)의 포도과즙 수율 증가를 나타냈다. 와인 색의 강도와 투명성의 결과는 실험군이 대조군에 비하여 색의 적색도가 강하게 나타났으며, 색도에서는 높은 선명도를 나타냈다. 또한, 펙틴이 pectinesterase(PE)에 의해 가수분해되어 발효 중에 메탄올 함량이 증가되었다. 관능검사를 통한 와인 품질과 관련된 기호 평가에서는 실험군이 대조군에 비해 외관, 향, 맛, 촉감이 우수함을 확인할 수 있었다. 이와 같이 pectinase의 처리에 의한 레드와인 발효 시, 다당류와 펙틴의 분해에 의해 레드와인의 품질 향상을 가져올 수 있음을 확인하였다. 본 연구를 토대로 와인제조 과정에서 pectinase의 효율성을 극대화하고, 메탄올 생성량의 감소 방안, 그리고 pectinase 처리 와인의 성분 분석과 기능이 세부적으로 연구된다면 와인품질 개선에 더 큰 효과를 기대할 수 있을 것으로 판단된다.

• Journal of Animal Science and Technology
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• 제65권1호
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• pp.96-112
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• 2023

Rye (Secale cereale L.) is a valuable annual forage crop in Korea but there is limited information about the impact of chemical and biological additives on fermentation characteristics of the crop. This experiment was conducted to investigate fermentation dynamics of wilted forage rye treated with the following six additives; control (no additive), sodium diacetate applied at 3 g/kg wilted forage weight (SDA3), 6 g/kg wilted forage weight (SDA6), inoculations (10⁶ CFU/g wilted forage) of Lactobacillus plantarum (LP), L. buchneri (LB), or LP+LB. The ensiled rye sampled at 1, 2, 3, 5, 10, 20, 30, and 45 days indicated that the acidification occurred fast within five days of storage than the rest of the storage period. The microbial inoculants decline the pH of ensiled forage, more rapidly than the control or SDA treated, which accompanied by the decrease of water-soluble carbohydrates and increase of lactic acid. Compared with the control silage, all treatments suppressed ammonia-nitrogen formation below to 35 g/kg DM throughout the sampling period. Suppression of total microbial counting occurred in SDA6, LP, and LP + LB. The lactic acid production rates were generally higher in microbial inoculation treatments. Acetic acid concentration was lowest in the LP-treated silage and highest in the SDA- and LB-treated silages. The in vitro dry matter (DM) digestibility and total digestible nutrients were the highest in the silage treated with SDA (6 g/kg) at day 45 of ensiling. Based on lower ammonia-nitrogen concentrations and higher feed value, ensiling forage rye treated with SDA at 6 g/kg is promising through enhanced silage quality.

• 한국식품조리과학회지
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• 제19권5호
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• pp.631-639
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• 2003

In order to control the quality and safety of cooked foods, production and holding methods of foods should be carefully studied and applied to the foodservice industry. Therefore studies on microbiological, nutritional, physicochemical and sensory quality are essential in this area. The purpose of this study was to evaluate the chemical and microbial qualities of cooked foods during preparation and holding From the results, the following guidelines should be adhered to give effective quality control when holding foods after cooking in foodservice institutions, as well as to provide quality foods when selling cooked foods at commercial establishments. Sauteed and simmered foods such as sauteed chicken meat & vegetables and simmered pork in soy sauce satisfy the standard for microorganisms till 1-3 hours of room temp. holding, 6-18 hours at 60$^{\circ}C$ steam table, and 12-18 hours at 80$^{\circ}C$ heating table.