• Journal of Dairy Science and Biotechnology
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• 제35권3호
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• pp.152-161
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• 2017

Cheese is an excellent substrate for yeast and mold growth. These organisms can cause cheese spoilage, resulting in significant food wastage and economic losses. In the context of cheese spoilage, the presence and effects of spoilage or pathogenic bacteria are well documented. In contrast, although yeasts and molds are responsible for much dairy food wastage, only a few studies have examined the diversity of spoilage fungi. This article reviews the spoilage yeasts and molds affecting cheeses in various countries. The diversity and number of fungi present were found to depend on the type of cheese. Important fungi growing on cheese include Candida spp., Galactomyces spp., Debaryomyces spp., Yarrowia spp., Penicillium spp., Aspergillus spp., Cladosporium spp., Geotrichum spp., Mucor spp., and Trichoderma spp.. In addition, several mold spoilage species, such as Aspergillus spp. and Penicillium spp., are able to produce mycotoxins, which may also be toxic to humans. There are many ways to eliminate or reduce toxin levels in foods and feeds. However, the best way to avoid mycotoxins in cheese is to prevent mold contamination since there are limitations to mold degradation or detoxifications in cheese. Chemical preservatives, natural products, and modified atmosphere packaging have been used to prevent or delay mold spoilage and improve product shelf life and food safety.

• 한국환경보건학회지
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• 제7권1호
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• pp.51-57
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• 1981

This Study was carried out to investigate yeast and mold contamination in fermented milk products produced by 9 different domestic manufacturers from October 20. to December 5. 1980 The results obtained in the study were as follows 1) pH values of the products were ranged from pH 3.14 to pH 4.20 and average of sour milk drinks was pH $3.66\pm 0.19$ and fermented milks pH $3.74\pm 0.11$. Therefore the difference of pH average among sour milk drinks and fermented milks was statistically significant. (p<0.01) 2) In case of yeast contamination, yeast was found on all the four producted at the same date. From this result, it seemed that yeast contamination occured during the manufacturing progress. 3) Degree of contamination by the indicator organisms was E. coli positive, 3.7%: over 1,000 yeasts/ml, 14.8% over 10 molds/ml, 0.9%. 4) In the range of over 1,000 yeasts/ml, degree of contamination by yeast was 8.4% in fermented milk and 16.7% in sour milk drink. 5) Yeasts in product C increased to the spoilage number within 5 days and in H increased within 10 days at 5C. At 15$\circ$C, yeast increased to the spoilage number within 15 days in product A.D. 6) It seems that the yeast number of initial contamination should be important than the increase rate as criteria on the fermented Milk products.

• 한국식품조리과학회지
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• 제4권1호
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• pp.41-46
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• 1988

오미자차액은 여름철의 음료나 화채의 기액으로서 많이 사용하고 있는데, 그 열매는 산을 많이 함유하고 있어 pH가 낮아(2.8-3.0) 미생물의 성장을 효과적으로 저해할 수 있는 pH를 가지나 $25^{\circ}C$에 저장했을 때 부패가 일어나는 것이 확인되었고 부패균은 곰팡이와 효모이었으며 세균은 관찰되지 않았다. 저장 중 부패되고 있는 오미자차액의 적정산도나 pH에는 그다지 큰 변화가 없었고 열매를 걸러낸 오미자차액에서의 적정산도는 열매가 들어있는 오미자차액보다 낮았는데, 그 이유는 열매가 들어 있는 오미자차액의 열매에서 산이 계속 용출되어 나왔기 때문으로 판단된다. 열매를 거른 오미자차액의 부패가 열매가 들어 있는 오미자차액보다 조금 빠르며 그 저장성도 열매를 거른 오미자차액이 낮은 것으로 나타났다. 그러나 오미자차액의 색상과 맛의 효과로서는 걸러서 보관하되 장기적인 저장은 바람직하지 못하다.

• The Plant Pathology Journal
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• 제26권4호
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• pp.353-359
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• 2010

In order to control postharvest spoilage of satsuma mandarin fruits, rhizobacteria were isolated from soil samples. The Pantoea agglomerans strain 59-4 (Pa 59-4) which suppresses the decay of mandarin fruit by green and blue mold, was tested for the control efficacy and its mode of action was investigated. Pa 59-4 inhibited infection by green and blue mold on wounded mandarins, which were artificially inoculated with a spore suspension of Penicillium digitatum and P. italicum with control efficacies of 85-90% and 75-80%, respectively. The biocontrol efficacy was increased by raising the concentration of cells to between $10^8$ and $10^9\;cfu/ml$, and pretreatment with the antagonist prevented subsequent infection by green mold. The population of Pa 59-4 was increased more than 10 fold during the 24 hr incubation at $20^{\circ}C$, indicating that colonization of the wound site might prevent the infection by green mold. Despite poor antifungal activity, the Pa 59-4 isolate completely inhibited the germination and growth of P. digitatum spores at $1{\times}10^8\;cfu/ml$. We argue that the control efficacy was mediated by nutrient competition. Overall, the effective rhizobacterium, Pa 59-4, was shown to be a promising biocontrol agent for the postharvest spoilage of mandarin fruits by green and blue mold.

• Preventive Nutrition and Food Science
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• 제8권1호
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• pp.89-92
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• 2003

The effect of gamma-irradiation on microbiological growth in kale juice during storage was studied. Fresh kale juice was prepared and irradiated at 0, 1, 3, 5, 7, 10, and 15 kGy. D values for total bacteria, yeast and mold, Salmonella, E. coli, and Pseudomonas were 3.6, 4.0, 3.2, 1.4, and 1.6 kGy, respectively. E. coli and Pseudomonas were eliminated completely at 5 and 7 kGy, respectively. Gamma-irradiation also reduced total viable bacteria during storage. Therefore, these results indicate gamma-irradiation can prevent microbial spoilage of fresh kale juice by inactivating pathogenic microorganisms.

• 한국식품영양과학회지
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• 제22권3호
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• pp.359-366
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• 1993

Molds are eucaryotic, multicellular, multinucleate, filamentous organisms that reproduce by forming asexual and sexual spores. The spores are readily spread through the air and because they are very light-weight and tend to behave like dust particles, they are easily disseminated on air currents. Molds therefore are ubiquitous organisms that are found everywhere, throughout the environment. The natural habitat of most molds is the soil where they grow on and break down decaying vegetable matter. Thus, where there is decaying organic matter in an area, there are often high numbers of mold spores in the atmosphere of the environment. Molds are common contaminants of plant materials, including grains and seeds, and therefore readily contaminate human foods and animal feeds. Molds can tolerate relatively harsh environments and adapt to more severe stresses than most microorganisms. They require less available moisture for growth than bacteria and yeasts and can grow on substrates containing concentrations of sugar or salt that bacteria can not tolerate. Most molds are highly aerobic, requiring oxygen for growth. Molds grow over a wide temperature range, but few can grow at extremely high temperatures. Molds have simple nutritional requirements, requiring primarily a source of carbon and simple organic nitrogen. Because of this, molds can grow on many foods and feed materials and cause spoilage and deterioration. Some molds ran produce toxic substances known as mycotoxins, which are toxic to humans and animals. Mold growth in foods can be controlled by manipulating factors such as atmosphere, moisture content, water activity, relative humidity and temperature. The presence of other microorganisms tends to restrict mold growth, especially if conditions are favorable for growth of bacteria or yeasts. Certain chemicals in the substrate may also inhibit mold growth. These may be naturally occurring or added for the purpose of preservation. Only a relatively few of the approximately 100,000 different species of fungi are involved in the deterioration of food and agricultural commodities and production of mycotoxins. Deteriorative and toxic mold species are found primarily in the genera Aspergillus, Penicillium, Fusarium, Alternaria, Trichothecium, Trichoderma, Rhizopus, Mucor and Cladosporium. While many molds can be observed as surface growth on foods, they also often occur as internal contaminants of nuts, seeds and grains. Mold deterioration of foods and agricultural commodities is a serious problem world-wide. However, molds also pose hazards to human and animal health in the form of mycotoxins, as infectious agents and as respiratory irritants and allergens. Thus, molds are involved in a number of human and animal diseases with serious implication for health.

• 한국식품영양과학회지
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• 제32권3호
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• pp.413-417
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• 2003

빵 부패미 생물에 대한 녹차추출물의 항균활성을 조사하고 녹차가루를 첨가한 찐빵의 저장 중 항균효과를 알아보고자 하였다. 사용된 세균 3종류인 Bacillus subtilis ARCC 6633, Bacillus pumilus KCTC 3348, Bacillus cereus IFO 12113과 곰팡이 Aspergillus niger KCCM l1239 모두 GTE 1% 이상에서 우수한 항균력을 가지고 있으며, 생육이 억제됨을 확인하였다. GTE의 열 안정성은 넓은 온도 범위(50~20$0^{\circ}C$)에서 열을 가하지 않았을 때와 동일하게 항균력이 유지되었고, pH 사용범위 (4~9)에 관계없이 동일한 환으로 항균력을 나타내었다. 녹차를 첨가한 찐빵을 $25^{\circ}C$에 저장하면서 총 곰팡이 수와 총 세균 수를 측정한 결과 대조군, GTP 1%, 3% 첨가군 모두 저장 3일째에 곰팡이가 나타났으나 GTP 5% 첨가군에서는 저장 3일째에 나타났다. 총 세균 수는 저장 3일 이후 $10^{7}$ CFU/g을 넘어 부패가 진행 중이었으나 GTP 3%는 5일째에, GTP 5% 첨가군은 7일째에 $10^{7}$ CFU/g을 나타났다. 그러므로 찐빵에서의 녹차의 항균 효과에 따른 저장기간 연장은 녹차가루 첨가량 5% 이상의 수준에서 가능하리라고 추측된다.

• 대한가정학회지
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• 제23권2호
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• pp.37-43
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• 1985

The effect of irradiation at dose of 3~10 kGy on the extension of the shelf-life of sliced dried squid and dried file and on its quality were investigated during nine months of storage at room temperature. The number of microorganisms, TBA value and TMA-N content were used as objective indices concerned to the sensory evaluation. In the number of initial microbial loading, total bacterial count of sliced dried squid and dried file fish were $2.7{\times}10^{8}\;and\;2.0{\times}10^{5}$, yeast and mold were $5.7{\times}10^{5}\;and\;6.2{\times}10^{5}$ and coliform group were $2.1{\times}10^{5}$ and above 10 per gram of the samples, respectively. The number of total bacteria was sterilized by 99% with irradiation of 3~10 kGy and irradiation of above 7 kGy was shown to be effective for the radurization of yeast, mold and coliform group. TBA value of irradiated groups were higher than storage time. The TMA-N content of nonirradiated group was markedly increased by microbial spoilage during storage, however above 8 kGy irradiated group were indicated about 10 mg% after nine months storage. In the sensory evaluation, the nonirradiated group was off favor after three months storage and was changed in color of dried fishes but 7~10 kGy irradiated group were maintained good qualit compared with those of fresh samples after nine months storage at room temperature.

• Asian-Australasian Journal of Animal Sciences
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• 제33권7호
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• pp.1103-1112
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• 2020

Objective: To measure whether a microbial additive could effectively improve the fermentation quality of delayed-sealing (DS) silage, we studied the effects of inoculants of lactic acid bacteria (LAB) and cellulase enzyme on microbial populations, ensiling characteristics, and spoilage loss of DS silage of Napier grass in Africa. Methods: Quick-sealing (QS) and DS silages were prepared with and without LAB (Lactobacillus plantarum) inoculant, cellulase enzymes, and their combination. The QS material was directly chopped and packed into a bunker silo. The DS material was packed into the silo with a delay of 24 h from harvest. Results: In the QS silage, LAB was dominant in the microbial population and produced large amounts of lactic acid. When the silage was treated with LAB and cellulase, the fermentation quality was improved. In the DS silage, aerobic bacteria and yeasts were the dominant microbes and all the silages were of poor quality. The yeast and mold counts in the DS silage were high, and they increased rapidly during aerobic exposure. As a result, the DS silages spoiled faster than the QS silages upon aerobic exposure. Conclusion: DS results in poor silage fermentation and aerobic deterioration. The microbial additive improved QS silage fermentation but was not effective for DS silage.

• Asian-Australasian Journal of Animal Sciences
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• 제27권6호
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• pp.832-840
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• 2014

This study aimed to investigate the effects of storage duration and temperature on the characteristics of wet brewers grains (WBG) as feeds for ruminant animals. Four storage temperatures ($5^{\circ}C$, $15^{\circ}C$, $25^{\circ}C$, and $35^{\circ}C$) and four durations (0, 1, 2, and 3 d) were arranged in a $4{\times}4$ factorial design. Surface spoilage, chemical composition and microorganism density were analyzed. An in vitro gas test was also conducted to determine the pH, ammonia-nitrogen and volatile fatty acid (VFA) concentrations after 24 h incubation. Surface spoilage was apparent at higher temperatures such as $25^{\circ}C$ and $35^{\circ}C$. Nutrients contents decreased concomitantly with prolonged storage times (p<0.01) and increasing temperatures (p<0.01). The amount of yeast and mold increased (p<0.05) with increasing storage times and temperatures. As storage temperature increased, gas production, in vitro disappearance of organic matter, pH, ammonia nitrogen and total VFA from the WBG in the rumen decreased (p<0.01). Our results indicate that lower storage temperature promotes longer beneficial use period. However, when storage temperature exceeds $35^{\circ}C$, WBG should be used within a day to prevent impairment of rumen fermentation in the subtropics such as Southeast China, where the temperature is typically above $35^{\circ}C$ during summer.