• Food Science and Preservation
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• v.20 no.2
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• pp.215-221
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• 2013

The objective of this study was to evaluate the changes in the physicochemical and microbiological characteristics of pork loin meat through microwave treatment. The microwave treatment was divided into two groups: continuing microwave treatment (CW) and holding microwave treatment (HW). The microwave treatment resulted in a whiter color (L value) and affected the a, b value. The initial pH was 5.51~5.74, but it increased to 6.32~6.51 when the pork loin samples were stored for three days. During storage for 14 days, the pH changes were not significantly different (p>0.05). The thiobarbituric-acid values of all the pork loin samples increased along with the storage period, and decreased with increasing microwave dose. The volatile basic nitrogen (VBN) content of the control was higher than those of the other samples, and the VBN content decreased along with the microwave dose. The total plate counts of the pork loin samples decreased with increasing microwave dose. The study results indicated that T2 (100 W, HW) is most effective for the safety of pork loin meat without decreasing the meat's physicochemical and microbiological characteristics.

• Korean Journal of Microbiology
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• v.28 no.3
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• pp.249-257
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• 1990

In the course of operating the accommodative and detoxifying mechanism against cadmium, its physio-biochemical changes were observed in Klebsiella aerogenes ATCC 10031. Changes of enzyme activity concerned phosphate metabolism, changes of phospholipid composition and in view of energy metabolism the changes of the nucleotide pool were examined. Activities of both alkaline and acid phosphatase were derepressed 4-10 folds under cadmium added cultures. Moreover, production of phospholipid such as lysophosphatidyl choline (LPC), phosphatidyl serine (PS) and phosphatidyl ethanolamone (PE) was increased and uridylate nucleotide pool was increased under Cd-surplus culture. These results i.e. overproduction of phosphatase catalyzing phosphate residue, increase of the production of PE and PS which have a close affinity with cadmium, and indrease of uridylate nucleotide pool used as a carrier of polysaccharide synthesis like bacterial capsule exhibited cellular responses for active defence against Cd-pressure. It was postulated that these phenomena should play another assistant roles in Cd-detoxifing mechanism.

• Korean journal of food and cookery science
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• v.17 no.3
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• pp.224-228
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• 2001

We studied the effects that the addition of Kimchi has on microbiological properties of fermented sausages as we observed pH and microbiological changes of Kimchi-added fermented sausage by aging period. The pH figure of sausages added with commercial starter culture was 5.69 at the beginning stage and declined gradually to 5.01. The more Kimchi is added, the lower pH figure goes. Sausages with 10% and 20% of fresh Kimchi, and 2% and 4% of powdered Kimchi added, showed about pH 5.4 at the early stage and down to pH 4.87 as they are stored longer. In terms of microbiological changes, sausages mixed with starter culture showed 10$\^$7/cfu/g level in the number of total bacteria, lactic acid bacteria, yeast and fungi, lower than Kimchi-added sausages. However, the figure soared sharply to 10$\^$10/cfu/g during the aging period. Kimchi-added sausages recorded 10$\^$9/cfu/g, slightly high during the eurly aging stage, in the number of total bacteria, lactic acid bacteria, yeast and fungi, while showing a gradual increase up to 10$\^$10/cfu/g towards the end of aging period and became microbiologically stabilized.

• Journal of Nutrition and Health
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• v.36 no.2
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• pp.223-230
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• 2003

The purpose of this study was to evaluate the effects of HACCP implementation. The HACCP education was provided twice within one month to 20 employees of a contracted food service operation in Daegu. Critical control points (CCP) were determined based on food preparation processes: non-heating, preparation after heating, and heating. We evaluated the effects of HACCP implementation by checking microbiological quality, time and temperature at each of the CCPs during the receiving, preparation, cooking, and serving stages. After HACCP implementation, the biggest changes in microbiological qualities were in heated foods. At the cooking and serving stages, the microbiological qualities of heated foods improved to the standard levels. HACCP education helped employees ensure that the internal temperatures of the heated foods were kept higher than the standard (74 $^{\circ}C$) and the food holding temperature avoided the dangerous zone (5-6$0^{\circ}C$), thus lowering microbiological levels. At the serving stage, the microbiological levels of utensils also improved after HACCP education. This result strongly suggests that it is essential to educate employees in managing the temperature to treat foods safely. However, HACCP education didn't affect the microbiological levels of non-heated foods and foods prepared after heating, which continued to be higher than the standard. The reason for this was that poor microbiological quality seasonings were added to those types of foods. This indicates that seasoning factories as well as food service operations should implement HACCP to reduce hazards.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.569-573
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• 2009

The biochemical and microbiological changes of the hard clam shikhae were studied during fermentation at $4-18^{\circ}C$ for 45 days. For preparation of the shikhae, the shucked hard clams were blanched into 2% saline solution and were soaked in seasoning solution before mixing with salt, cooked grain and spices. During fermentation, the initial pH steadily decreased from 5.0 to 4.6, but $NH_2-N$ and VBN concentrations increased to 127 mg/100 g and 27.0 mg/100 g, respectively. Alanine, taurine, glutamic acid, and aspartic acid concentrations increased, but arginine concentration decreased by fermentation. The major organic acids of the fermented shikhae were lactic acid, succinic acid and acetic acid. The major free sugar were maltose, glucose and fructose. The concentration of total viable cell ($2.1\times10^5$ CFU/g) and proteolytic bacteria ($1.2\times10^5$ CFU/g) increased to $4.4\times10^8$ CFU/g and $9.8\times10^7$ CFU/g, respectively until day 15 and then slightly decreased. The concentration of yeast ($2.4\times10^3$ CFU/g) increased to $1.6\times10^7$ CFU/g until day 25, but lactic acid bacteria ($5.0\times10^8$ CFU/g) increased to $5.0\times10^8$ CFU/g until day 9. Vibrio species was not detected on the TCBS agar during fermentation.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.7
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• pp.960-964
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• 2010

Water-cooked salted ducks were tray-packaged and stored under refrigeration ($4{\pm}1^{\circ}C$) in order to evaluate the quality changes during storage. pH, total volatile basic nitrogen (TVB-N), sensory and microbiological analysis were determined at 0, 2, 4, 6, 8, 9 and 10 days of storage. pH value and TVB-N (mg N/100 g) varied from $6.47{\pm}0.16$ to $6.69{\pm}0.10$ and from $5.90{\pm}0.93$ to $13.42{\pm}2.46$, respectively. Sensory results indicated that ducks were unacceptable at the 10th day of storage. The predominant spoilage bacteria at the end of the shelf-life were Brochothrix thermosphacta, lactic acid bacteria (LAB) and minor components were Enterobacteriaceae, members of Micrococci, yeasts and moulds. Pseudomonads were also detected. Both total bacteria and the various spoilage ones, overall, increased from the initial sampling to the final day.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1811-1814
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• 2009

The effect of fermentation with mixed cultures of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus on the microbiological characteristics of oat extract was investigated. Changes in pH, titratable acidity and viable cell populations indicated that growth was better in mixed cultures of L. delbrueckii subsp. bulgaricus and S. salivarius subsp. thermophilus. Growth of S. salivarius subsp. thermophilus in oat extract was more rapid than growth of L. delbrueckii subsp. bulgaricus. Cooperative interaction between two cultures during fermentation of oat extract as in yogurt from cow's milk was observed, but the intensity was relatively weak.

• Journal of Ginseng Research
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• v.5 no.2
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• pp.99-107
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• 1981

Physical, chemical and microbiological changes were periodically studied during six-month storage of fresh ginseng under N2, CO2 gas or subatmospheric pressure condition. The results were summarized as follows. 1. The moisture contents of fresh ginseng gradually decreased during the first 2-month storage and thereafter generally reached at equillibrium. 2. There was no significant change in the reducing sugar content in 1-month storage, followed by$.$a decrease in between 2-and 3-month storage. Thereafter, the reducing sugar content increased at the end of 4-month storage. 3. The total sugar content increased significantly during the first 3-month storage. Under CO2 and Nr gas storage, the total sugar content gradually decreased after 3-month storage, while no significant change was observed in the samples stored under subatmospheric Pressure. Amylase activity gradually decreased as storage period increased 4. The content of saponin decreased as storage period increased, but ginsengoide Rf, Rd, Rc and Rb2 increased significantly in 1-month storage. 5. Regardless of storage methods, sprouting of ginseng and growth of microorganisms were inhibited in all samples during the first 4-month storage. However, growth of microorganisms was observed in the rhizome and injured areas of ginseng after 5-month storage in the N2 and CO2 gas atmosphere.

• Journal of Food Hygiene and Safety
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• v.12 no.1
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• pp.55-62
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• 1997

This study was carried out to investigate the microbiological and chemical properties of natural water during storage. The water samples were taken at the time of purchase and the opened bottles and unopened bottles stored at the temperature of 4$^{\circ}C$, 18$^{\circ}C$, and 3$0^{\circ}C$. The bacterial content normally rose to 2.06$\times$102 CFU/$m\ell$ for the unopened bottles and 2.91$\times$102 CFU/$m\ell$ for the opened bottles after 2 weeks of storage, and 1.21$\times$102 CFU/$m\ell$ and 2.64$\times$102, respectively, after 24 weeks of storage. The number of viable cells of bacteria peaked more rapidly at the storage temperature of 3$0^{\circ}C$ than 18$^{\circ}C$. But the total samples were found to be negative for coliforms test during the study period. The average range of pH value was from 7.39 to 7.76. The results showed that the nitrates and chlorides satisfied the Korea Drinking Water Quality Standards during the storage period of 24 weeks. However, the undesirable changes of the taste and odor were detected within 2 weeks and 3 weeks, respectively.

• Journal of Veterinary Clinics
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• v.15 no.1
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• pp.156-161
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• 1998

This study investigated the microbiological changes and distribution of bacteria producing enzyme in order to change food wastes to animal feed during 6 days at room temperature. Food wastes were divided as follows: one is untreated food wastes containing 80% water content and another wastes containing 40% water content adiusted by wheat bran. During the fermentation of food wastes, Lactobacillus sp. and Streptococcus sp. were grown the top position among investigated microorganisms in both of food wastes. Numbers of total microorganisms were much more than untreated wastes during fermentation of flood wastes with 40% water content. But, Streptococcus sp. and Enterobacteriaceae from 4 to 6 days were not detected in treated wastes with 40% water contents. This fact indicated that the adiustment of water content in food waste was effective in fermentation. However, the numbers of microorganisms producing pretense were low in both treated and untreated food wastes. These results suggested that flood wastes should be treated as food wastes with 40% water content to maintain a lot of fermentative microorganisms such as Lactobacillus sp., Streptococcus sp. and yeasts together with pretense to make final animal feed.