• Title/Summary/Keyword: microbiological and quality characteristics

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Isolation and Microbiological Characteristics of Bacillus megaterium SMY-212 for Prepartion of Black Bean Chungkugjang (검정콩 청국장 조제를 위한 Bacillus megaterium SMY-212의 분리 및 균학적 특성)

  • 손미예;권선화;성찬기;이상원;박석규
    • Journal of Life Science
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    • v.11 no.4
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    • pp.304-310
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    • 2001
  • In order to produce a high quality and functional black bean Chungkugjang, a bacterium which has potent enzyme activities(protease:124.8 U/$m\ell$, $\alpha$-amylase: 78.2U/$m\ell$, glucoamylase; 13.9U/$m\ell$, ), was isolated by using the halo zone method and identified by morphological, cultural and biochemical properties, and then finally confirmed by GP-microplate identification system as Bacillus megatrium SMY-212. The isolated SMY-212 system was also high in the formation of mucoid material and fibrinolytic activity.

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Evaluation of Sodium Alignate as a Fat Replacer on Processing and Shelf-life of Low-fat Ground Pork Patties

  • Kumar, Manish;Sharma, B.D.;Kumar, R.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.4
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    • pp.588-597
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    • 2007
  • Low-fat ground pork patties, LFGPP (<10% total fat) formulated with 0.1, 0.2 and 0.3 percent sodium alginate (SA) were processed and compositional, processing and sensory characteristics were compared with control patties containing 20% fat. The moisture content of raw and cooked LFGPP were significantly (p<0.05) higher than control patties because of greater amount of added water in the formulation. The cooking yield, moisture and fat retention also increased linearly in different treatments of LFGPP. The dimensional parameters such as gain in height, decrease in diameter and shrinkage were significantly (p<0.05) lower in LFGPP in comparison to control. Amongst the sensory attributes, flavour showed a declining trend with the increase in concentration of SA in LFGPP. However, low-fat patties with 0.1% SA rated similar to high-fat control. The lipid profile revealed 49.78 and 43.22% decrease in total lipids and cholesterol content respectively, compared to control. The calorie content was reduced significantly (p<0.05) in LFGPP. The texture profile of LFGPP with 0.1% SA was similar to that of high-fat control. The LFGPP remained stable without any appreciable loss of physico-chemical, microbiological and organoleptic quality during refrigerated storage ($4{{\pm}}1^{\circ}C$) for 21 and 35 days in aerobic and vacuum packaging respectively.

Gamma Irradiation of Ready-to-Cook Bulgogi Improves Safety and Extends Shelf-Life without Compromising Organoleptic Qualities

  • Jo, Cheo-Run;Han, Chang-Duk;Chung, Kang-Hyun;Byun, Myung-Woo
    • Preventive Nutrition and Food Science
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    • v.8 no.2
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    • pp.191-195
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    • 2003
  • We investigated the effects of gamma irradiation on the microbiological, chemical and sensory qualities of bulgogi, a traditional Korean meat product. Gamma irradiation reduced the number of coliform bacteria and bacterial colonies counted in Salmonella-Shigella selective agar to a non-detectable level. Thermophillic microorganisms (mainly Bacillus spp.) in bolgogi refrigerated for 20 days were also significantly reduced by 3 log cycles by 2.5 to 7.5 kGy of irradiation, compared to the control. Electron donating ability and shear force of ready-to-cook bulgogi was not significantly affected by gamma irradiation. Irradiation increased the 2-thiobarbituric acid reactive substances (TBARS) value. The irradiated, raw, ready-to-cook bulgogi had significantly higher scores in color and appearance than those of non-irradiated controls from sensory evaluation. The overall acceptance of cooked bulgogi had higher scores in non-irradiated or 2.5 kGy-irradiated bulgogi than the 5.0- or 7.5-kGy irradiated counterparts. In conclusion, irradiation at 2.5 kGy is recommended as a method to improve shelf-life, safety, and to achieve acceptable quality of ready-to-cook bulgogi without any adverse changes in the sensory characteristics.

Fermentation Characteristics of Kochujang in Onggis with Different Porosities (통기성이 다른 옹기에서의 고추장 발효 특성)

  • Chung, Sun-Kyung;Lee, Kwang-Soo;An, Duck-Soon
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.14 no.1
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    • pp.9-14
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    • 2008
  • The effect of different porosity of onggis, Korean earthenware, on the fermentation of kochujang was investigated. The porosity was controlled with glazing treatment. Three kinds of onggis were made: one with no glazing treatment, one with outside glazing treatment, and one with both inside and outside glazing treatment. During 4 month fermentation of kochujang in porosity-controlled earthenwares, physical, chemical, microbiological, and sensory quality attributes were monitored. Higher protease activity and higher contents of amino nitrogen, free amino acids, and total neucleotide were observed in kochujang fermented in the onggi with outside glazing treatment, which might have resulted in better sensory quality. Onggi with medium porosity could be effective for fermentation of kochujang.

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The Effect of Fresh Ginseng on the Quality Characteristics of Seukbakjee (수삼의 첨가가 섞박지의 품질특성에 미치는 영향)

  • Lim, Hee Jung
    • Korean journal of food and cookery science
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    • v.15 no.6
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    • pp.618-625
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    • 1999
  • This study was conducted to investigate the effect of fresh ginseng on the physicochemical, microbiological and sensory properties of Seukbakjee during 45 days of fermentation. Seukbakjee with various levels(0, 2, 4, 6%) of fresh ginseng were fermented at $4^{\circ}$. During fermentation, the pH values were lowered in all Seukbakjee samples, however, those with fresh ginseng were a little higher than control Seukbakjee. Acidity increased continuously during the entire fermentation, in which those of added fresh ginseng increased less than control. As the concentration of fresh ginseng increased, the pH of Seukbakjee were increased. Saltiness was maintained at 1.37~2.62% levels during the whole fermentation. The degree of degradation of reducing sugar and free sugar was much delayed in Seukbakjee added with fresh ginseng. Total vitamin C content of Seukbakjee with fresh ginseng was higher than that of Seukbakjee without fresh ginseng. The number of total bacteria and lactic acid bacteria in Seukbakjee with fresh ginseng was higher than control during the entire fermentation period. In sensory evalution, Seukbakjee with 4% fresh ginseng was the best for taste and flavor. Seukbakjee with 2% fresh ginseng was the best for texture and overall acceptability. Above results suggest that the addition of fresh ginseng improves the quality of Seukbakjee.

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Effects of calcium propionate on the fermentation quality and aerobic stability of alfalfa silage

  • Dong, Zhihao;Yuan, Xianjun;Wen, Aiyou;Desta, Seare T.;Shao, Tao
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.9
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    • pp.1278-1284
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    • 2017
  • Objective: To assess the potency of calcium propionate (CAP) used as silage additive, an experiment was carried out to evaluate the effect of CAP on the nitrogen transformation, fermentation quality and aerobic stability of alfalfa silages. Methods: Alfalfa was ensiled with four levels of CAP (5, 10, 15, and 20 g/kg of fresh weight [FW]) in laboratory silos for 30 days. After opening, the silages were analyzed for the chemical and microbiological characteristics, and subjected to an aerobic stability test. Results: The increasing proportion of CAP did not affect pH, lactic acid (LA) concentrations and yeast counts, while linearly decreased counts of enterobacteria (p = 0.029), molds (p<0.001) and clostridia (p<0.001), and concentrations of acetic acid (p<0.001), propionic acid (p<0.001), butyric acid (p<0.001), and ethanol (p = 0.007), and quadratically (p = 0.001) increased lactic acid bacteria counts. With increasing the proportion of CAP, the dry matter (DM) loss (p<0.001), free amino acid N (p<0.001), ammonia N (p = 0.004), and non-protein N (p<0.001) contents were linearly reduced, whereas DM (p = 0.048), water soluble carbohydrate (p<0.001) and peptide N (p<0.001) contents were linearly increased. The highest Flieg's point was found in CAP10 (75.9), represented the best fermentation quality. All silages treated with CAP improved aerobic stability as indicated by increased stable hours compared with control. Conclusion: The addition of CAP can suppress the undesirable microorganisms during ensiling and exposure to air, thereby improving the fermentation quality and aerobic stability as well as retarding the proteolysis of alfalfa silage. It is suggested that CAP used as an additive is recommended at a level of 10 g/kg FW.

Evaluation of Biodegradation Characteristics of Haloacetic Acids by a Biofilm in a Drinking Water Distribution System (상수관망에서 생물막에 의한 Haloacetic Acids 생물분해 특성 평가)

  • Son, Hee-Jong;Kim, Do-Hwan;Han, Young-Rip;Choi, Young-Ik
    • Journal of Environmental Science International
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    • v.23 no.9
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    • pp.1635-1642
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    • 2014
  • Haloacetic acids (HAAs) concentrations have been observed to decreased at drinking water distribution system extremities. This decrease is associated with microbiological degradation by pipe wall biofilm. The objective of this study was to evaluate HAAs degradation in a drinking water system in the presence of a biofilm and to identify the factors that influence this degradation. Degradation of monochloroacetic acid (MCAA), dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) was observed in a simulated distribution system. The results obtained showed that different parameters came into play simultaneously in the degradation of HAAs, including retention time, water temperature, biomass, and composition of organic matter. Seasonal variations had a major effect on HAAs degradation and biomass quantity (ATP concentration) was lower by 25% in the winter compared with the summer.

Determination of Quality Changes throughout Process ing Steps in Chinese-style Pork Jerky

  • Chen, W.S.;Liu, D.C.;Chen, M.T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.5
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    • pp.700-704
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    • 2004
  • Chinese-style pork jerky is a typical intermediate moisture meat product obtained by curing, drying and roasting pork samples. The chemical, physical and microbiological characteristics of pork jerky were evaluated throughout processing. The moisture content varied from 72.5% to 23.4 or 19.6% and aw varied form 0.97 to 0.74 or 0.72 in accordance with processing steps. The pork jerky roasted at $200^{\circ}C$ had higher shear value than roasted at $150^{\circ}C$ because the moisture content and aw of the former sample was lower than the later sample. The nitrite losses during whole processing steps amount to nearly 50%. The TBA value of pork jerky varied from 0.34 to 9.25 or 9.83 mg of malonaldehyde depended on processing steps. The VBN value of pork jerky ranging from 0.25 to 22.4 or 23.5 mg/kg depended upon processing steps. The ATPase activity of myofibrillar proteins during processing steps were partly or entirely denatured by the heat-drying or heat-roasting treatment. A gradual decrease in microorganism count during processing of pork jerky was also observed.

Comparative Characterization of the Bacteria Isolated from Market Milk Treated with ESL and Conventional System (ESL 생산공정에 따른 시유 유래 미생물의 분포 비교 연구)

  • 김응률;정병문;유병희;정후길;강국희;전호남
    • Food Science of Animal Resources
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    • v.23 no.4
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    • pp.327-332
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    • 2003
  • This study was conducted to investigate the characteristics of strains which were isolated from market milk treated with ESL(extended shelf life) and conventional system, and to compare the microbiological quality of ESL milk with conventional milk. In order to characterize the isolated strains, purification, Gram staining, spore staining, catalase, oxidase, motility test, and identification by means of automatic identificator were performed. The results obtained are as follows: total 364 selected strains were analyzed in this study. Depending upon the isolated source, the number of strains from conventional milk was found to be Higher than ESL-milk. By means of grouping of total strains, Bacillus ssp. and Staphylococcus ssp. showed to be predominant. But most of strains were distributed with various groups except Lactobacillus ssp. When the isolates were compared with milk process methods, Enterococcus ssp. was detected much on market milk treated with LTLT pasteurization. Also, Pseudomonas ssp. was detected much on conventional milk treated with UHT pasteurization. By comparison with genus groups depending upon storage temperature of market milk, the higher milk storage temperature increased, the most frequency detected Bacillus ssp. increased. Also, Pseudomonas ssp. was detected most frequently at 10$^{\circ}C$ storage condition. Generally this genus derived from post-contamination during milk processing and related to the quality of market milk during chilled system. In conclusion, it was shown that ESL system reduced post-contamination during milk process, following the improvement of product quality and life cycle during the distribution of market milk.

Storage Quality of Minimally Processed Onions as Affected by Seal-Packaging Methods (포장방법에 따른 신선 편의가공 양파의 저장품질 변화)

  • Hong, Seok-In;Son, Seok-Min;Chung, Myong-Soo;Kim, Dong-Man
    • Korean Journal of Food Science and Technology
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    • v.35 no.6
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    • pp.1110-1116
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    • 2003
  • The effects of packaging methods on the storage quality of minimally processed (prepeeled) onions were investigated to determine the optimal packing design. Various packaging treatments used for modifying headspace atmospheres included two passive MAP using LDPE and PP films, two active MAP using a gas mixture of 20% $O_2/10%\;CO_2/balance\;N_2$ and an ethylene scavenging sachet, and moderate vacuum packaging (MVP). The quality attributes of onion samples were evaluated periodically in terms of flesh weight loss, color of cut surface, decay ratio, microbial counts, and sensory properties during storage at $10^{\circ}C$ for 28 days. Packaging methods did not significantly influence surface color, weight loss, and microbiological populations of mesophiles, psychrotrophs, and lactic acid bacteria. They did, however, affect sensory characteristics as well as decay occurrence. Results indicated that seal-packaging with a gas-permeable plastic film under a mild vacuum condition could retain better onion quality in terms of microbial decay and visual sensory aspects as compared with the other packages.