• Title/Summary/Keyword: Microbial qualities

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Effect of Electron Beam Irradiation on Microbial Growth and Qualities in Astragalus membranaceus

  • Jin, You-Young;Shin, Hee-Young;Ku, Kyoing-Ju;Song, Kyung-Bin
    • Journal of Applied Biological Chemistry
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    • v.49 no.4
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    • pp.176-179
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    • 2006
  • Electron beam irradiation was applied to examine the microbial growth and qualities of vacuum-packaged Astragalus membranaceus, a Korean medicinal herb. Samples were irradiated at dose of 2, 4, 8, 12, and 16 kGy, respectively. Microbiological data on A. membranaceus showed that populations of total bacteria, yeast and mold, total coliforms were significantly reduced with increase of irradiation dose. Populations of microorganisms in A. membranaceus were decreased by 2-3 log cycles at 8 kGy irradiation. Color measurements showed that electron beam treatment caused negligible changes in Hunter color L, a, and b values of A. membranaceus. Sensory evaluations showed that there were no significant changes among the samples. These results suggest that electron beam irradiated A. membranaceus have better microbial safety and qualities, compared with the non-irradiated control.

Chemical and Biological Indicators of Soil Quality in Conventional and Organic Farming Apple Orchards

  • Lee, Yoon-Jung;Chung, Jong-Bae
    • Journal of Applied Biological Chemistry
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    • v.50 no.2
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    • pp.88-96
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    • 2007
  • Organic farming systems based on ecological concepts have the potential to produce sustainable crop yields with no decline in soil and environmental qualities. Recent expansion of sustainable agricultural systems, including organic farming, has brought about need for development of sustainable farming systems based on value judgments for key properties of importance for farming. Chemical and microbiological properties were chosen as indicators of soil quality and measured at soil depth intervals of 5-20 and 20-35 cm in conventional and organic-based apple orchards located in Yeongchun, Gyeongbuk. The orchards were two adjacent fields to ensure the same pedological conditions except management system. Soil pH in organic farming was around 7.5, whereas below 6.0 in conventional farming. Organic farming resulted in significant increases in organic matter and Kjeldahl-N contents compared to those found with conventional management. Microbial populations, biomass C, and enzyme activities (except acid phosphatase) in apple orchard soil of organic farming were higher than those found in conventional farming. Higher microbial quotient ($C_{mic}/C_{org}$ ratio) and lower microbial metabolic quotient for $CO_2(qCO_2)$ in organic farming confirmed that organic farming better conserves soil organic carbon. Biological soil quality indicators showed significant positive correlations with soil organic matter content. These results indicate organic-based farming positively affected soil organic matter content, thus improving soil chemical and biological qualities.

Effects of Storage Temperature and Packaging Methods on the Microbiological and Organoleptic Qualities of Boiled-Dried Anchovies (저장온도 및 포장방법이 건멸치의 미생물학적 및 관능적 품질에 미치는 영향)

  • 권중호;이기동;변명우;조한옥
    • Journal of Food Hygiene and Safety
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    • v.10 no.2
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    • pp.103-109
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    • 1995
  • Microbiological and organoleptic qualities of boiled anchovies were evaluated during storage for 8 months at different temperatures and packaging methods. Microbial populations of marketing samples were 106~107 CFU/g in aerobic bacteria, 103~106 CFU/g in yeasts/molds and 103~105 CFU/g in coliforms, respectively, which were the highest in retail sample, followed by in military goods and wholesale sample. Moreover, anchovies supplied for retail sale and military goods were contaminated with sanitary indicative microbes. The samples stored at ambient condition(15~33$^{\circ}C$, RH 5$0^{\circ}C$95%) lost their marketable quaity mainly due to microbial propagation prior to 6 months, irrespective of packaging methods, corrugated-cardboard box and laminated-film(nylon 15${\mu}{\textrm}{m}$/PE 100${\mu}{\textrm}{m}$). However, cooling(5~1$0^{\circ}C$) as well as well as freezing temperatures($\leq$-18$^{\circ}C$) following laminated-film packaging were effective for keeping the organoleptic qualities of stored anchovies up to 8 months. The population of yeasts and molds was shown the quality-indicative criteria for stored anchovies and their critical levels were 5.00 log counts/g, showing a higher negative-correlationship(r=-0.901) with changes in organoleptic quality.

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A Study on the Microbiological Quality of Vegetables in Relation to the Sanitization Method Used and Vegetable Types (채소군별 미생물학적 안전성 확보를 위한 적정 소독방법)

  • Kim, Heh-Young;Lee, Yun-Hee
    • Korean journal of food and cookery science
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    • v.25 no.5
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    • pp.632-642
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    • 2009
  • In this study the microbiological quality of vegetables was evaluated in relation to the sanitization methods used and vegetable types which consisted of raw food ingredients used in foodservice operations. We analyzed the microbial quantities on lettuce and spinach, which were used as leaf vegetables and cucumber and tomato, which were used as fruit vegetables according to various disinfection methods using different chlorine concentration(50 ppm, 100 ppm, 200 ppm) and exposure time(5 min, 10 min) over 5 days. When the effects of the disinfection methods on microbial qualities and sensory evaluation were analyzed, the following results were obtained. First, in the leaf vegetables, disinfection with a chlorine concentration of 200 ppm for a 5 minutes exposure time was needed to control microbial growth. Second, fruit vegetables sterilized with tap water had reduced microbial qualities after an extended amount of time relative to chlorine disinfection, that is, disinfection with a chlorine concentration of 50 ppm for 5 minutes exposure time was desirable.

Effect of Aqueous Chlorine Dioxide Treatment on the Microbial Growth and Qualities of Strawberries During Storage

  • Jin, You-Young;Kim, Yun-Jung;Chung, Kyung-Sook;Won, Mi-Sun;Song, Kyung-Bin
    • Food Science and Biotechnology
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    • v.16 no.6
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    • pp.1018-1022
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    • 2007
  • Effect of aqueous chlorine dioxide treatment on the microbial growth and quality changes of strawberries during storage was examined. Strawberries were treated with 5, 10, and 50 ppm of chlorine dioxide solution, and stored at $4{\pm}1^{\circ}C$. Total aerobic bacteria in strawberries treated at 50 ppm of chlorine dioxide were increased from 1.40 to 2.10 log CFU/g after 7 days, while increasing in the control from 2.75 to 4.32 log CFU/g. Yeasts and molds in strawberries treated at 50 ppm of chlorine dioxide were increased from 1.10 to 1.97 log CFU/g after 7 days, while the control was increased from 2.55 to 4.50 log CFU/g. The pH and titratable acidity of strawberries were not significantly different among treatments. Sensory evaluation results showed that chlorine dioxide-treated strawberries had better sensory scores than the control. These results indicate that chlorine dioxide treatment could be useful in improving the microbial safety and qualities of strawberries during storage.

Evaluation of the quality of Danhopak tzeam prepared with the Sous vide Cook-Chill System and Conventional Cook-Chill System (Sous vide Cook-Chill System과 Conventional Cook-Chill System으로 생산된 단호박찜의 미생물적 품질평가)

  • Ko, Sung-Hee;Kim, Heh-Young;Oh, Kyung-Sook
    • Korean journal of food and cookery science
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    • v.22 no.4 s.94
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    • pp.504-513
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    • 2006
  • This study was performed to provide basic data for the operation of a safer cook-chill system by comparing and evaluating the quality of food prepared using the sous vide cook-chill(SVCC) and cook-chill(CC) systems, according to the preparation methods and storage temperature. When the effects of preparation methods and storage temperatures on the physicochemical and microbial qualities were analyzed, the following results were obtained. Firstly, the microbial risk was reduced and the food was raised when danhopark tzeam were prepared with SVCC compared with CC in which changes in pH and Aw and moisture content loss were less than with SVCC. Secondly, the storage period tested in this study was limited to only 10 days, which prevented any significant difference from being seen at 3$^{\circ}$C and 10$^{\circ}$C in the degradation of food quality when SVCC and CC were compared. However, the overall quality and safety as indicated by the physicochemical and microbial qualities at 10$^{\circ}$C were relatively low for and with CC, suggesting that SVCC is a more effective method, probably because vacuum packing eliminates oxygen in the food, thereby inhibiting bacterial growth.

Studies on Holding Methods for Quality Assurance of Salads Served at Foodservice Institutions (급식소에서 제공되는 샐러드류의 조리후 보관방법 설정을 위한 품질 연구)

  • 김혜영;고성희
    • Korean journal of food and cookery science
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    • v.20 no.2
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    • pp.211-218
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    • 2004
  • The issue of safety and quality of cooked food served at foodservice institutions has brought more attention to food scientists because the foodservice system is growing and becoming more popular in Korea. In order to control the quality and safety of cooked foods, the production and holding methods of foods should be carefully studied and the implications considered by the foodservice industry. Therefore, studies on microbiological, nutritional, physicochemical and sensory quality are essential in this area. The purpose of the present study was to evaluate the chemical and microbial qualities of salads during holding. Several holding temperatures in the range of 5∼26$^{\circ}C$ were used for holding. Chicken salad and ham & cucumber salad exceeded the standard after 30min of room temperature holding after preparation. Quality deterioration increased at higher holding temperatures, which suggested that refrigerator holding is the most desirable.

Improvement of the Functional Qualities of Sea Tangle Extract through Fermentation by Aspergillus oryzae

  • Bae, Hyang-Nam;Kim, Young-Mog
    • Fisheries and Aquatic Sciences
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    • v.13 no.1
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    • pp.12-17
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    • 2010
  • This study was conducted to evaluate the potential of a microbial fermentation procedure to improve the functional qualities of seaweeds. Aspergillus oryzae, which has been used in traditional Korean fermented foods, was inoculated and cultivated in an aqueous extract of sea tangle (Laminaria japonica). Fermentation of the sea tangle extract by A. oryzae for 4 days resulted in a 3-fold increase in $\gamma$-aminobutyric acid (GABA) content. GABA is known to be a bioactive compound. Fungal fermentation of the extract also enhanced its antioxidant activity and increased its total content of phenolic compounds. It was assumed that these changes stemmed from the biodegradation of active compounds of the sea tangle packaged within its rigid structural matrix or occurred as result of fungal fermentation. These results suggested that the application of microbial fermentation to the processing of seaweeds will help in the development of processed foods to meet consumer demands.

Quality of steak restructured from beef trimmings containing microbial transglutaminase and impacted by freezing and grading by fat level

  • Sorapukdee, Supaluk;Tangwatcharin, Pussadee
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.1
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    • pp.129-137
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    • 2018
  • Objective: The objective of this research was to evaluate the physico-chemical, microbiological and sensorial qualities of restructured steaks processed from beef trimmings (grade I and II) and frozen beef (fresh beef as control and frozen beef). Methods: Beef trimmings from commercial butcher were collected, designated into 4 treatments differing in beef trimmings grade and freezing, processed into restructured steaks with 1% microbial transglutaminase and then analyzed for product quality. Results: The results showed that all meat from different groups could be tightly bound together via cross-linking of myosin heavy chain and actin as observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Microbial counts of psychrotrophic and mesophilic bacteria were not affected by treatments (p>0.05), and no detectable of thermophilic bacteria were found. Regarding effect of beef trimmings grade, steaks made from beef trimmings grade II (16.03% fat) showed some superior sensorial qualities including higher tenderness score (p<0.05) and tendency for higher scores of juiciness and overall acceptability (p<0.07) than those made from beef trimmings grade I (2.15% fat). Moreover, a hardness value from texture profile analysis was lower in steaks processed from beef trimmings grade II than those made from grade I (p<0.05). Although some inferior qualities in terms of cooking loss and discoloration after cooking were higher in steaks made from beef trimmings grade II than those made from beef trimmings grade I (p<0.05), these differences did not affect the sensory evaluation. Frozen beef improved the soft texture and resulted in effective meat binding as considered by higher cohesiveness and springiness of the raw restructured product as compared to fresh beef (p<0.05). Conclusion: The results indicated the most suitable raw beef for producing restructured steaks without detrimental effect on product quality was beef trimmings grade II containing up to 17% fat which positively affected the sensory quality and that frozen beef trimmings increased tenderness and meat binding of restructured beef steaks.

Effect of Electron Beam Irradiation on the Microbial Safety and Qualities of Sliced Dried Squid (전자선 조사가 건조 오징어의 미생물학적 안정성 및 품질에 미치는 영향)

  • Ko, Jong-kwan;Ma, Yu-hyun;Song, Kyung-Bin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.3
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    • pp.433-437
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    • 2005
  • Electron beam irradiation was applied to examine the microbial safety and qualities of sliced dried squid. Sliced dried squid was irradiated at dose of 2, 4, 8, 12, and 16 kGy. Microorganisms contaminated in sliced dried squid were significantly decreased by irradiation. Decimal reduction dose (D/sub 10/ value) of total bacteria count, yeast and mold, coliforms in sliced dried squid were 8.57, 4.60, and 8.10 kGy, respectively. Electron beam irradiation caused negligible changes in Hunter color L, a, and b value. Sensory evaluations of irradiated sliced dried squid showed that there were no significant changes among the samples. These results indicate that electron beam irradiation improves the microbial safety and qualities of sliced dried squid.