• Title/Summary/Keyword: microbiological quality evaluation

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Effect of rearing system (free-range vs cage) on gut and muscle histomorphology and microbial loads of Italian White breed rabbits

  • Caterina Losacco;Antonella Tinelli;Angela Dambrosio;Nicoletta C. Quaglia;Letizia Passantino;Michele Schiavitto;Giuseppe Passantino;Vito Laudadio;Nicola Zizzo;Vincenzo Tufarelli
    • Animal Bioscience
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    • v.37 no.1
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    • pp.151-160
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    • 2024
  • Objective: The growing consumers' interest on animal welfare has raised the request of products obtained by alternative rearing systems. The present study was conducted to assess the influence of housing system on gut and muscle morphology and on microbial load in rabbits reared under free-range (FR) and cage system (CS). Methods: A total of forty weaned (35 days of age) male Italian White breed rabbits were allotted according to the rearing system, and at 91 days of age were randomly selected and slaughtered for the morphological evaluation of tissue from duodenum and longissimus lumborum. Morphometric analysis of the villus height, villus width, crypt depth, villus height/crypt depth ratio, and villus surface was performed. The microbial loads on hind muscle was determined by total mesophilic aerobic count (TMAC), Escherichia coli and Enterobacteriaceae; whereas, total anaerobic bacteria count (TABC) and TMAC, E. coli and Enterobacteriaceae was determined on caecal content. Results: Rearing system did not interfere with the duodenum and muscle histomorphology in both rabbit groups. Similarly, microbial load of caecal content showed no significant differences on the TABC and TMAC. Conversely, significant difference was found for E. coli strains in caecal content, with the lower counts in FR compared to CS rabbits (p<0.01). Microbiological assay of muscle revealed significant lower TMAC in FR vs CS rabbits (p< 0.05). All rabbit meat samples were negative for E. Coli and Enterobacteriaceae. Conclusion: Free-range could be considered a possible alternative and sustainable rearing system in rabbits to preserve gut environment and muscle quality.

Effect of Gamma Irradiation on the Microbiological and Physicochemical Quality Changes of Steamed Waxy Corns during Storage (감마선 조사에 의한 증자 찰옥수수의 저장 중 미생물 및 이화학적 특성변화)

  • Choi Jae-Ho;Im Ji-Soon;Oh Deog-Hwan
    • Food Science and Preservation
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    • v.13 no.3
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    • pp.292-298
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    • 2006
  • Effect of gamma irradiation on the microbiological and physicochemical characteristics of steamed waxy corns was determined in order to develop preservation techniques to enhance shelf-life during storage at room or low temperature. The initial total microbial count, and yeast & molds steamed waxy corns before irradiation were $2.1{\times}10^3CFU/g,\;1.9{\times}10^3CFU/g$, respectively. However, the total microbial count were completely inactivated and the count of yeast and molds were only 34 CFU/g at 3 kGy treatment When non-irradiated steamed waxy corns were stored at $25^{\circ}C$ for 7 months, the growth of total microbial counts and yeasts & molds were rapidly increased up to $7.1{\times}10^6CFU/g\;and\;1.9{\times}10^7CFU/g$, respectively. However, the total microbial counts at 3 kGy treatment and yeast & molds at 5 kGy treatment for 7 month storage were completely inactivated Similar result was observed at $15^{\circ}C$ and $4^{\circ}C$ storage. The Hardness of the irradiated steamed waxy corns and irradiation dose were not significantly different from those of the non-irradiated steamed waxy corns before storage, but the hardness of non-irradiated steamed waxy corns was significantly increased during the storage, compared to those of irradiated corns. The water content of both irradiated and non-irradiated steamed waxy corns after 7 month storage were significantly decreased from $65{\sim}60%$ to 30% but the changes of water content among treatments or irradiation doses were not significantly different during storage. Sugar contents in the irradiated steamed waxy corns were less free than those of non-irradiated samples and the amount of free sugar slowly increased as storage temperature increased. Sensory evaluation result showed that total sensory scores in irradiated steamed waxy corns were better than those of non-irradiated samples and total sensory scores were increased as irradiation doses increased.

Quality Characteristics of the Simple Preprocessed Food Julienne White Radish and Pear during Storage and Development of a Standard Recipe (단순 가공 식품재료 활용을 위한 혼합무배생채의 저장기간에 따른 품질특성 및 레시피 기준 설정)

  • Park, Ji-Hyun;Baek, Ok-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.21 no.5
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    • pp.706-712
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    • 2011
  • This study was carried out to investigate the quality characteristics and microbiology of the simple preprocessed food julienne white radish and pear during storage at $4^{\circ}C$ and fordevelopment of a standard recipe. Total aerobic bacteria level were $3.20{\pm}0.08$ log CFU/g in julienne white radish and pear, and $3.00{\pm}0.14$ log CFU/g in julienne white radish (control). Coliform counts were $3.20{\pm}0.08$ log CFU/g in julienne white radish and pear and $1.84{\pm}0.17$ log CFU/g in julienne white radish. Low levels of coliform and total aerobic bacteria were detected. pH values of julienne white radish and pear increased significantly after 3days, whereas that of control increased significantly after 1day. Lightness and redness decreased during storage, whereas yellowness increased significantly during storage. During storage, hardness of julienne white radish and pear decreased after 3days, whereas that of julienne white radish decreased after 5days. According to sensory evaluation, 70% julienne white radish and 30% julienne pear showed higher score in term of taste, harmony of ingredient, harmony of sauce and overall preference. Consequently, 70% julienne white radish and 30% julienne pear was determined to the best formula and a maximum storage period of 3 days was showned to be optimal.

Quality Changes in Various Heat-treated Market Milks during Storage (열처리를 달리한 시유의 저장중 품질 변화)

  • Kwon, Soon-Ha;Ahn, Joung-Jwa;Kwak, Hae-Soo
    • Journal of Dairy Science and Biotechnology
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    • v.16 no.2
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    • pp.90-97
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    • 1998
  • This study was carried out to investigate changes of microbiological and sensory properties in various heat-treated market milks (LTLT, HTST, and UHT milks) stored at 10$^{\circ}C$ during 15d. Titratable acidity (TA) increased with storage, while pH tended to decrease. During the initial 9d, no difference was found in TA, however, after 9d, it was slightly higher in HTST and UHT milks than that in LTLT milk. In LTLT and HTST milks, total viable cells and psychrotrophs were dramatically increased during storage, In addition coliform and pathogenic bacteria were found at 12 and 15d. In UHT milk, total viable cells were found only at 15d. In sensory evaluation, LTLT and HTST milks developed a negligible off-flavor until 9d. At 12d, it became stronger in HTST milk than that in LTLT milk. In UHT milk, off-flavor was detected at 9d and increased rapidly there-after. The degree of off-flavor was little higher in HTST and UHT milks, compared with that of LTLT milk after 9d storage. These observations indicated that LTLT and HTST milks may not be microbiologically acceptable after 5d, while off-flavor was not detectable until 9d, In comparison, UHT milk keeps a good quality in microorganism until 15d, however, it may not be accepted in sensory aspect after 9d storage.

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Quality Characteristics of Yulmoo Mul-kimchi Containing Saltwort (Salicornia herbacea L.) (함초 분말 첨가 열무 물김치의 품질특성)

  • Park, Jung-Eun;Lee, Jae-Yong;Jang, Myung-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.7
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    • pp.1006-1016
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    • 2011
  • Saltwort (Salicornia herbacea L.), as a natural additive for regulating Mul-kimchi fermentation, was assessed for physicochemical and sensory characteristics of Yulmoo Mul-kimchi during storage. Saltwort in the form powder was directly added to the Yulmoo Mul-kimchi preparation at 0 (control), 1, 3, 5, and 7% (w/v) per weight of salt to evaluate their physicochemical, sensory, and microbiological characteristics in storage at $10^{\circ}C$ for 30 days. The pH values of all treatments were high, indicating a less acidic environment in all treatments compared to those of the control sample throughout the preservation period. Total acidity increased with storage time as is usually seen with normal kimchi fermentations, whereas the increases were more gradual in the 3 and 5% treatments. The increases in total vitamin C continued until days 6 (control) to 13 (7%), and were different according to the amount of added saltwort and then they decreased after each peak. The fluctuation in reducing sugars fol owed a similar trends of total vitamin C content by showing an initial increase, followed by a decrease based on the saltwort concentration and storage day. The 5% treatment was most effective for suppressing the increase in turbidity among all treatments. The 3 and 5% treatments showed the highest lactic acid bacteria counts during the entire preservation period. In the sensory evaluation results, adding saltwort at more than 3% concentration attained an overall higher scores of acceptability with respect to color, smell, taste, fresh taste, sour taste, crisp, and overall acceptability characteristics. In conclusion, adding saltwort, particularly at concentrations of 3 and 5% extended the preservation period of Yulmoo Mul-kimchi by retarding fermentation effectively.

Effect of Preparation method and Fermentation Conditions on Microbiological Characteristics of Sikhae (어류를 이용한 식해의 제조 방법에 따른 미생물의 특성변화)

  • Kim, Young-Sook;Oh, Seung-Hee;Kim, Soon-Dong
    • Food Science and Preservation
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    • v.15 no.6
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    • pp.909-914
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    • 2008
  • This study investigated microbial populations and the sensory quality of sikhae including globefish (GLS), flounder (FLS), gastropods (GAS) and whelks (WHS) during storage at 4C for 16 d following fermentation at 10C for 4 d. General bacterial numbers increased to 102 in GLS and FLS, and to 1045 in WHS and GAS after the 20 d fermentation/storage period. Lactic acid bacteria increased to 108 log cycle in GLS and FLS after 10 d ripening time, and reached this level in GAS and WHS after 15 d and 20 d, respectively. After 20 days the number of lactic acid bacteria in each of the four samples was 108. There were 104105 yeast cells/g in each of the four samples after 20 d. The number of Leuconostoc increased to over 108 log cycle after 10 d in GLS and FLS, and 15 days in GAS for WHS the increase was to 107 log cycle. The pH values of GLS, FLS, GAS and WHS 4.42, 4.56, 4.31 and pH 4.26, respectively. The Sikhae acidity for all four samples ranged from 1.551.85%. From the sensory evaluation the overall acceptability was in the order of FLS > GLS > GAS > WHS.

Effects of Gamma Irradiation and Ethylene Oxide Fumigation for the Quality Preservation of Spices and Dry Vegetables (건조향신 조미식품의 품질보존을 위한 효과적인 살균방법에 관한 비교연구)

  • 신광순;마점술;조종후
    • Journal of Food Hygiene and Safety
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    • v.4 no.2
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    • pp.119-132
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    • 1989
  • Gamma irradiation as a new physical treatment was applied to comparative investigates with a conventional ethylene oxide fumigant on the microbiological and physicochemical qualities of selected spices and dry vegetables such as powdered red pepper, black pepper, welsh onion, onion, garlic, carrot, korean cabbage and instant ramyon soup. The microorganisms contaminated in the sample, including total viable count, thermophilic bacteria, aerobic spore and fungi counts between the $10^4\;to\;10^6/g$ range. Coliforms were found only in black pepper and welsh onion powder as the $10^2\;to\;10^3/g$ level. A radiation dose of 7 to 10 KGy were sterilized completely to the contaminated microorganisms, while ehthylene oxide (E.O.) fumigation reduced of them to the $10^3/g$ level. An optimum dose of irradiation was less detrimental than E.O. fumigation to the physicochemical properties of the sample. Sensory evaluation after three months of storage at room temperatures showed that the overall acceptability of irradiated sample was higher than that of the non treated control as well as E.O. fumigated samples. Comparison gamma irradiation with E.O. gas treatment showed that E.O. treatment was less effective than radiation in cotrolling microbial contamination of spices and vegetables.

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Effect of Pre-preparation with Vinegar against Microorganisms on Vegetables in Foodservice Operations (단체급식에서 채소류 전처리를 위한 식초 소독의 미생물적 효과)

  • 김소희;정수열
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.2
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    • pp.230-237
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    • 2003
  • For hygenic evaluation, microbiological tests of seasoned raw vegetal)les from five high school foodservice operations were conducted. The antimicrobiological effect of pre-preparation with vinegar against microorganisms on vegetables in foodservice operations was also investigated. Total plate counts of leek gukgalli, broad bellflower saengchae and vegetable salad ranged from 10$^4$ CFU/g to 10$^{6}$ CFU/g. Coliform levels of those ranged from 10$^2$CFU/g to 10$^4$ CFU/g. Leek washed three times was pre-prepared at different concentration (0.05%,0.1%,0.5%,1% and 2%) and temperature ( 1$0^{\circ}C$ 2$0^{\circ}C$ and 4$0^{\circ}C$) for 5, 10 and 30 minutes. The higher the concentration and temperature of vinegar were, the more the antimicrobiological activity increased. The sanitizing activity of vinegar increased with treatment time. Considering the quality of vegetable and the expense, when the levels of total plate counts and coliform of vegetable were 10$^{6}$ and 10$^3$ CFU/g, pre-preparation with 0.5% of vinegar at 2$0^{\circ}C$ for 10 minutes was best. The population of total plate count and coliform on row and leek washed three times increased during storage for 72 hours. However, The levels of microorganism on leek samples pre-prepared with 0.5% and 1% vinegar decreased during storage. After the treatment of vinegar at 1$0^{\circ}C$ for 10 minutes, Staphylocucus aureus, Escherichia coli O157, Shigella sonnei, Salmonella entritidis, Listeria monolytogenes were not detected.

Quality Changes and Pasteurization Effects of Citrus Fruit Juice by High Voltage Pulsed Electric Fields (PEF) treatment (고전압 펄스 전기장 처리에 의한 감귤주스의 품질변화)

  • Kim, Kyung-Tack;Kim, Sung-Soo;Hong, Hee-Do;Ha, Sang-Do;Lee, Young-Chun
    • Korean Journal of Food Science and Technology
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    • v.35 no.4
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    • pp.635-641
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    • 2003
  • A non-thermal pasteurization technology, high Pulsed Electric Field (PEF) has been thought to be a new alternative processing technology instead of heating. The objective of this study was to examine and compare the effect of PEF and High Temperature Short Time (HTST) treatments on the physicochemical, microbiological and sensory characteristics of citrus juices. Total sugar and titratable acidity values of fresh citrus juice and two treatments were not significantly different each other at p<0.05. The concentration of vitamin C in fresh citrus juice $(31.2{\pm}0.59\;mg%)$ was not significantly different with the value of PEF treatment $(29.4{\pm}0.75\;mg%)$ but was significantly higher than the value of HTST treatment $(27.4{\pm}0.75\;mg%)$. The color values (L, a, and b) in PEF treatment were significantly lower than the fresh citrus juice, but were higher than the values of HTST treatment. Both total bacterial cell counts $(6.65\;{\pm}\;0.08\;log_{10}(cfu/mL))$ and yeast counts $(7.79{\pm}0.07\;log_{10}(cfu/mL))$ in fresh citrus juice were significantly reduced by PEF $(1.39{\pm}0.14,\;2.42{\pm}0.1\;log_{10}(cfu/mL))$ as well as HTST treatment (0, 0). PE activity of fresh citrus juice $(1.3{\pm}0.12\;units/mL)$ was significantly reduced by PEF treatment $(0.11{\pm}0.01\;units/mL)$ and was totally inactivated by HTST treatment. Sensory evaluation scores in flavor, taste and overall acceptability between the fresh and PEF treated citrus juices $(7.2{\sim}7.5)$ were not significantly different but the values of HTST treatment $(5.1{\sim}5.8)$ were lower than others. Consequently, PEF treatment is thought to be a good alternative pasteurization method for fresh citrus juice to HTST treatment due to its strong pasteurization effect, reduced destruction of nutrients and good sensory characteristics.