• Title/Summary/Keyword: Microbial qualities

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Effect of Storage Temperature and Humidity on the Quality of Apples and Pears harvested in Gyeongnam, Korea (경남산 사과 및 배의 저장온습도별 품질변화)

  • 신영희;조성환
    • Food Science and Preservation
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    • v.8 no.3
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    • pp.269-273
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    • 2001
  • Apples and pears for investigating the optimal storage conditions were purchased from the farmhouse located in Hadong-Goon and Geochang-Goon Gyeongnam just before the beginning of this experiment. Apples and pears were, stored under 70%(storage temperature : 25$^{\circ}C$), 80%(10$^{\circ}C$) and 90%(5$^{\circ}C$) of relative humidity, respectively and their qualities in microbial counts, decay ratio, surface color difference and chemical attributes were monitored during the storage period. Apples and pears stored under 70% of relative humidity showed the minimal change in weight lass, decrease ratio of ascorbic acid content, surface color difference and degrees contaminated by putrefactive microorganisms. As the results of this experiment, apples and pears stored under 90% of relative humidity showed the optimal storage conditions for maintaining their freshness.

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Effects of Omija (Schizandra chinensis Baillon) on the Sensory and Microbiological Properties of Nabak Kimchi during Fermentation (오미자가 나박김치의 발효 중 관능적 및 미생물학적 특성에 미치는 영향)

  • 문성원;장명숙
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.29 no.5
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    • pp.822-831
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    • 2000
  • Application of omija(Schizndra chinensis Baillon) to improve the quality and preservation of nabka kimchi was attempted and the optimal amount of omija level and its effect on the sensory and microbiological properties of nab마 kimchi during fermentation were examined. Effects of omija juice which had been prepared by extracting omija seeds for 9 hr at room temperature (22.5$\pm$0.5$^{\circ}C$) with different ratios (0.5, 1.0, 1.5, 2.0%;w/v) of water were examined against control (kimchi prepared without omija). Organoleptic and microbiological properties of nabak kimchi were measured up to 25 days at 1$0^{\circ}C$ after preparation. Sensory properties were evaluated in the aspects of both acceptability and intensity characteristics. In whole, 0.5 and 1.0% treatments showed higher values of evaluation, compared to control, 1.5, and 2.0% treatments throughout the fermentation period. As fermentation progresses, however, sample of 1.0% treatment ranked first between day 4 to 7 and also so did sample of 0.5% treatment along with 1.0% treatment from behind day 10. As for color, control, 0.5% treatment, and 1.0% treatment were more favored than rest of the samples. In texture, 2.0% treatment showed the highest values, whereas control was rated the lowest. In the intensity of characteristics 1.5% and 2.0% treatments showed higher values except sweet taste in which 1.0% treatment ranked top during the initial 7 days and then 0.5% treatment took the first place at behind day 10. total cell counts and number of lactic acid bacteria were gradually increased and then decreased showing the maximum levels of microbial counts on different days, to say, day 2 for control and 0.5% treatment nd day 7 for 1.0, 1.5 and 2.0% treatments. The application of omija juice in nabak kimchi enhanced eating qualities of the fermented product and the fermentation-retarding effect of omija juice was clearly shown during the initial seven days of fermentation. The optimum levels of omija juice in nabak kimchi obtained through experiments were between 0.5 to 1.0% for color, fermentation-retarding effects, and savory taste of the product.

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Physicochemical and Microbiological Characterization of Protected Designation of Origin Ezine Cheese: Assessment of Non-starter Lactic Acid Bacterial Diversity with Antimicrobial Activity

  • Uymaz, Basar;Akcelik, Nefise;Yuksel, Zerrin
    • Food Science of Animal Resources
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    • v.39 no.5
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    • pp.804-819
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    • 2019
  • Ezine cheese is a non-starter and long-ripened cheese produced in the Mount of Ida region of Canakkale, Turkey, with a protected designation of origin status. Non-starter lactic acid bacteria (NSLAB) have a substantial effect on the quality and final sensorial characteristics of long-ripened cheeses. The dominance of NSLAB can be attributed to their high tolerance to the hostile environment in cheese during ripening relative to many other microbial groups and to its ability to inhibit undesired microorganisms. These qualities promote the microbiological stability of long-ripened cheeses. In this study, 144 samples were collected from three dairies during the ripening period of Ezine cheese. Physicochemical composition and NSLAB identification analyses were performed using both conventional and molecular methods. According to the results of a 16S rRNA gene sequence analysis, 13 different species belonging to seven genera were identified. Enterococcus faecium (38.42%) and E. faecalis (18.94%) were dominant species during the cheese manufacturing process, surviving 12 months of ripening together with Lactobacillus paracasei (13.68%) and Lb. plantarum (11.05%). The results indicate that NSLAB contributes to the microbiological stability of Ezine cheese over 12 months of ripening. The isolation of NSLAB with antimicrobial activity, potential bacteriocin producers, yielded defined collections of natural NSLAB isolates from Ezine cheese that can be used to generate specific starter cultures for the production of Ezine cheese (PDO).

Partial replacement of pork backfat with konjac gel in Northeastern Thai fermented sausage (Sai Krok E-san) to produce the healthier product

  • Sorapukdee, Supaluk;Jansa, Sujitta;Tangwatcharin, Pussadee
    • Asian-Australasian Journal of Animal Sciences
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    • v.32 no.11
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    • pp.1763-1775
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    • 2019
  • Objective: The influence of konjac gel level on fermentation process and product qualities were assessed to evaluate the feasibility of using it as fat analog in Northeastern Thai fermented sausage (Sai Krok E-san). Methods: Five treatments of fermented sausages were formulated by replacing pork backfat with 0%, 7.5%, 22.5%, and 30% konjac gel. The changes in lactic acid bacteria (LAB) and important physicochemical properties of samples were assessed during 3 days of fermentation. After the end of fermentation at day 3, water activity ($a_w$), instrumental texture, color, microbial counts, and sensory evaluation were compared. The best product formulation using konjac for replacing pork back fat were selected and used to compare proximate composition and energy value with control sample (30% pork backfat). Results: An increase in konjac gel resulted in higher values of LAB, total acidity, and proteolysis index with lower pH and lipid oxidation during 3 days of product fermentation (p<0.05). It was noted that larger weight loss and product shrinkage during fermentation was observed with higher levels of konjac gel (p<0.05). The resulting sausage at day 3 with 15% to 30% konjac gel exhibited higher hardness, cohesiveness, gumminess, springiness, and chewiness than control (p<0.05). The external color of samples with 22.5% to 30% konjac gel were redder than others (p<0.05). Mold, Salmonella spp., Staphylococcus aureus, and Escherichia coli in all finished products were lower than detectable levels. Product with 15% konjac gel had the highest scores of sourness linking and overall acceptability (p<0.05). Conclusion: The product with 15% of konjac gel was the optimum formulation for replacing pork backfat. It had higher sensorial scores of sourness and overall acceptability than control with less negative impact on external appearance (product shrinkage) and weight loss. Moreover, it provided 46% fat reduction and 32% energy reduction than control.

Comparison of physicochemical traits of dry-cured ham from purebred Berkshire and crossbred Landrace × Yorkshire × Duroc (LYD) pigs

  • Yim, Dong-Gyun;Jung, Jong-Hyun;Ali, Md. Mhahbbat;Nam, Ki-Chang
    • Journal of Animal Science and Technology
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    • v.61 no.1
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    • pp.35-40
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    • 2019
  • This study was conducted to compare the physicochemical traits of dry-cured hams made from two different pig breeds: Berkshire and $Landrace{\times}Yorkshire{\times}Duroc$ (LYD). Pigs were slaughtered at a live weight of approximately 110 kg and cooled at $0^{\circ}C$ for 24 h in a chilling room. Then, the ham portion of the carcasses were cut and processed by dry-curing for physicochemical analyses. The dry-cured hams from Berkshire contain higher crude protein, fat, and ash level than those from LYD, whereas the hams from LYD had higher moisture contents than those from Berkshire(p < 0.05). The pH values of the hams from Berkshire were lower than those from LYD (p < 0.05). The hams from Berkshire had lower $L^*$ and $b^*$ values than those from LYD (p < 0.05). Palmitoleic acid (C16:1), oleic acid (C18:1), elaidic acid (C18:1t), monounsaturated fatty acids, and ratio of n-6 and n-3 fatty acids (n-6/n-3) in the ham from Berkshire were higher than LYD (p < 0.05). Free amino acids such as aspartic acid, threonine, serine, asparagine, glutamic acid, and lysine in hams from Berkshire were higher than those from LYD (p < 0.05). The microbial population had no significant difference between Berkshire and LYD dry-cured ham. The cross sections of dry cured ham showed difference from different breeds using scanning electron microscope and indicates some differences in texture. Considering the meat quality parameters of ham, hams from Berkshire could provide variety of ham for consumer who are seeking various different qualities and stories.

Evaluation of Compost Qualities with or without Microbial Inoculation for Food Waste Composting (미생물제 첨가유무에 따른 음식물 쓰레기 퇴비 부숙도 평가)

  • Jeong, Jun-Young;Jung, Kwang-Yong;Nam, Sung-Suk
    • Korean Journal of Environmental Agriculture
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    • v.18 no.3
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    • pp.280-286
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    • 1999
  • This studies were conducted to evaluate efficiency of microbial inoculator for active composting of food wastes. The Microbial inoculators used in this studies were purchased from different comparise to evaluate their effectiveness for composting of food waste in Korea. The number of bacteria growing at $30^{\circ}C$ in commercial inoculator collected were below $91.0{\times}10^8\;CFU/g$ which were counted from well cured compost made by animal manure. The number of bacteria in commercial microbial inoculator, such as FL, VP, B9, CM and GE were higher than that of composted at $50^{\circ}C$ or $60^{\circ}C$ of incubation temperature. Fungi were counted in GR, VP and B9 as over $10^3CFU/g$ at $30^{\circ}C$ of incubation temperature, while fungi of all the commercial inoculator collected could not grown at $50^{\circ}C$ and $60^{\circ}C$. Actinomycetes in most of the these had higher number($10^5CFU/g$) than that of compost : however, it was not detected at $60^{\circ}C$ incubation temperature from all the samples collected. The amount of carbon dioxid production was order to VP>HU>B9>GE>CM>Control>Compost in the lab scale composting test with or without inoculation of commercial inoculators, however, but the difference in carbon dioxide production was similar among each treatments. The effect of inoculation on composting parmeter such as pH changes, temperature increasing and change of chemicals properties were a little among each treatments, with or without inoculation of commercial inoculator in active composting of food waste. Using commercial inoculator did not show any statistical difference in food waste composting process under various condition such as pH changes, temperature changes, etc.

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Microbial Qualities of Parasites and Foodborne Pathogens in Ready to Eat (RTE) Fresh-cut Produces at the On/Offline Markets (즉석섭취 신선편의 절단 과일 및 채소의 원충류 및 병원성 식중독균의 미생물학적 품질 실태 연구)

  • Jeon, Ji Hye;Roh, Jun Hye;Lee, Chae Lim;Kim, Geun Hyang;Lee, Jeong Yeon;Yoon, Ki Sun
    • Journal of Food Hygiene and Safety
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    • v.37 no.2
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    • pp.87-96
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    • 2022
  • Recently, the purchase of fresh-cut produce and meal kits has increased. Ready-to-eat (RTE) fresh-cut products have potentially hazard of cross-contamination of various microorganisms in the processes of peeling, slicing, dicing, and shredding. There are frequent cases of protozoa food poisoning, such as Cyclospora and Cryptosporidium, caused by fresh-cut products. The objective of the study is to investigate the microbiological qualities of various types of RTE fresh-cut products in the domestic on/offline markets. RTE fresh-cut fruits cup (n=100), fresh-cut vegetables (n=50), and vegetables in meal kits (Vietnamese spring rolls and white radish rolls kits, n=50) were seasonally analyzed. The contamination levels of hygienic indicator organisms, yeast and mold (YM), and foodborne pathogens (Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, Salmonella spp., and Escherichia coli O157:H7) were monitored. Overall, the lowest microbiological qualities of meal kits vegetables were observed, followed by RTE fresh-cut fruits cup and fresh-cut vegetables. Contamination levels of total aerobic bacteria, coliforms, and YM in meal kits vegetables were 5.91, 3.90, and 4.71 logs CFU/g, respectively. From the qualitative analysis, 6 out of 200 RTE fresh-cut products (3%) returned positive result for S. aureus. From the quantitative analysis, the contamination levels of S. aureus in purple cabbage from a meal-kit and fresh-cut pineapple were below the acceptable limit (100 CFU/g). Staphylococcus enterotoxin seg and sei genes were detected in RTE fresh-cut celery and red cabbage from meal-kits, respectively. S. aureus contamination must be carefully controlled during the manufacturing processes of RTE fresh-cut products. Neither Cyclospora cayetanensis nor Cryptosporidium parvum was detected in the samples of RTE fresh-cut products and vegetables from meal-kits from the Korean retail markets.

Soil Carbon and Microbial Activity Influenced by Pasture and Rice Paddy Management (목초재배지 및 벼논 관리 변화에 따른 토양 탄소 및 미생물 활성도)

  • Yoo, Ga-Young;Kim, Hyun-Jin;Kim, Ye-Sol;Jung, Min-Hung
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.3
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    • pp.435-443
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    • 2012
  • This study investigated soil carbon storage and microbial activities influenced by different management practices in rice paddies and pastures. Soils under a single-crop farming of rice (CON) and rice-Italian ryegrass rotation farming (IRG) were compared in Jangheung, Jeollanam-do, Seocheon and Cheonan, Chungcheongnam-do. Soils from pastures were analyzed to investigate the effect of duration period (P1, P2, P3) in Namwon, Jeollabuk-do and Seosan, Chungcheongnam-do. In rice paddy, total and particulate carbon (PC) concentrations in the IRG soils were significantly higher than those in the CON soils both in Jangheung and Seocheon where the IRG has been established for three years, whereas carbon concentrations were not significantly different in Cheonan where IRG planting history is only one year. In rice paddy soils, PC was suggested as an early indicator to monitor changes in soil carbon storage followed by adopting different management practices. In pasture, total and PC concentrations increased with duration period especially in the 0-5 cm soils. Contrary to the rice paddy soils, the magnitude of change in PC concentration is not as great as that in total carbon concentration, implying that there is a need to develop a new early indicator other than PC using different fractionation scheme. The soil carbon storage in pasture also increased with years since establishment and the increasing rate was significantly greater in the early stage (0-5 yrs) than the later one (> 5 yrs). Microbial activities measured from fluorescein diacetate (FDA) hydrolysis analysis were significantly lower in the IRG soils than CON soils, whereas no difference was observed in the pastures of different ages. This shows that FDA activity is not a sensitive indicator to differentiate soil qualities influenced by management practices if it is used by itself.

Effect of Morus alba Root Bark, Ecklonia stolonifera, and Curcuma aromatica Extracts on Shelf-life and Quality of Castella (상백피, 곰피 및 강황 추출물 첨가에 의한 카스텔라의 저장성 및 품질증진 효과)

  • Yoon, So-Young;Choi, Jung-Soo;Lee, So-Young;Kim, Koth-Bong-Woo-Ri;Song, Eu-Jin;Kim, Seo-Jin;Lee, So-Jeong;Lee, Chung-Jo;Kim, Tae-Wan;Ahn, Dong-Hyun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.10
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    • pp.1444-1451
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    • 2009
  • This study was to examine the shelf life and qualities of castellas added with mixture of Morus alba root bark (MA), Ecklonia stolonifera (ES), and Curcuma aromatica (CA) extracts (MECE). The result of total microbial cell count showed that castellas with MECE were increasing storage time, especially at the rate of MA : ES : CA=0.75:0.75:0.5, and was reduced about 3 log cycle as compared to that of control. Also castellas with MECE were shown to have the highest antioxidant effect by Rancimat method. In the color, redness of castellas diminished with increasing amounts of MECE in castellas while conversely, lightness and yellowness increased. In sensory evaluation, the castella containing MA 0.25%, ES 0.25% and CA 0.125% were preferred than the control. These results suggest that the addition of MA 0.25%, ES 0.25% and CA 0.125% in castella positively improved the preservation and development of quality.

Effect of Ecklonia cava Hot Water Extracts on Shelf-life and Quality of Muffin (감태 열수 추출물 첨가에 의한 머핀의 저장성 및 품질 증진 효과)

  • Jung, Kyong-Im;Choi, Young-Ju;Cho, Eun-Kyung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.11
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    • pp.1672-1677
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    • 2010
  • The purpose of this study was to examine the qualities of muffins made with 0.1, 0.5, and 1% of Ecklonia cava hot water extracts (WEC). The muffins containing 0.1, 0.5, and 1% of WEC were acceptable by sensory evaluation such as color, flavor, taste, texture, and overall acceptability. The moisture contents of muffins made with WEC were not significantly different from muffins not containing WEC (control) during the early storage period (p<0.05), whereas after 3 days of storage, the moisture contents of muffins made with WEC were higher than that of control. The total microbial count in muffins made with 1% of WEC decreased as compared to that of control with an increase in storing time. The antioxidative activities, DPPH radical scavenging and superoxide dismutase-like activity of muffins increased with an increase in the concentrations of WEC. These results suggest that the addition of WEC to muffins has a good effect on improving the shelf-life and overall quality.