• Title/Summary/Keyword: total bacterial counts

Search Result 347, Processing Time 0.04 seconds

A study on the Shelf-life Extension of Minimally Processed Carrot (최소가공 당근의 유통기한 연장 연구)

  • Lee, Kyoung-Hae;Lim, Hui-Kyoung
    • Journal of Food Hygiene and Safety
    • /
    • v.23 no.4
    • /
    • pp.330-337
    • /
    • 2008
  • Betarich carrots were washed at various hypochloric acid(HCA) concentration and steeping time and packed in PE bag keeping at $8^{\circ}C$ for 12 days, in order eventually to examine microbiology, firmness, surface color, whiteness index(WI) and sensory quality. It was found that total bacterial counts at T-II and T-III with the 3 minute steeping were $4.37{\pm}0.19\;\log\;CFU/g$ and $4.27{\pm}0.13\;\log\;CFU/g$ respectively, showing slight decrease compared to control condition. E. coli was not detected at all treatments but less coliforms were detected at the 8-day treatments of T-II and T-III. Treatment of 3-minute steeping showed smaller reduction in firmness than that of I-minute steeping at 12-days, and T-1 (T-3) had the largest (smallest) reduction among them. It was also found that during the treatment the L-value showed decreasing trend, but the parameter a- and b-value showed increasing trend. WI increased, and its change was small with the increase in HCA concentration. The sensory quality check after 8 day storage showed that evaluation of the off-flavor appeared to be significantly high (p<0.05) at both non-treatment and HCA treatment. On the basis of the results above, it is likely to be more effective to prolong the period of circulation of beta rich carrots if you use HCA over 50 ppm for washing betarich carrots. This study will contribute to improve safety and quality in circulation of beta rich carrots.

The Quality Characteristics of Aralia continentalis Kitagawa Jangachi by Storing Time (저장기간에 따른 땅두릅 장아찌의 품질특성)

  • Han, Gwi-Jung;Shin, Dong-Sun;Jang, Myung-Sook
    • Korean journal of food and cookery science
    • /
    • v.25 no.1
    • /
    • pp.8-15
    • /
    • 2009
  • This study was carried out to examine changes in the quality characteristics of Aralia continentalis Kitagawa (AcK) Jangachi made with different $CaCl_2$ and seasoning treatments during storage at $4^{\circ}C$ for 6 months. The results exhibited there were no significant changes in pH, acidity, and salinity in the various samples. The numbers of total bacterial counts and lactic acid bacteria increased slowly during the early storage period and then increased rapidly in the third month. In the fifth month they reached their highest level near $6.6{\times}10^{6}cfu/ml$ and then decreased thereafter. The sample treated with $CaCl_2$ exhibited a higher degree of hardness than the untreated sample. Finally, the sensory characteristics of the AcK Jangachi were highly acceptable during the entire storage period in terms of color, smell, bitterness, texture, and general preference regardless of the $CaCl_2$ treatments.

The Manufacturing of Low-fat Hamburger Patties Added Organic Vegetable (친환경 유기농 채소가 첨가된 저지방 햄버거 패티의 제조)

  • Chung, Ku-Young;Chung, Eui-Ryung;Lee, Joo-Yeon
    • Food Science of Animal Resources
    • /
    • v.28 no.2
    • /
    • pp.165-170
    • /
    • 2008
  • In this study, the physicochemical, microbial, and sensory properties of law-fat hamburger patties during storage for 25 days at $7{\pm}1^{\circ}C$ were investigated. The law-fat hamburger patties were manufactured by three different packing methods (control: added with 10% lard regular-fat patty, T1: added with 10% lard and organic vegetable of regular-fat patty, T2: added with 3% olive oil of vegetability low-fat patty, T3: added with 3% lard of low-fat patty). The pH of all treated samples increased as the storage time increased, and then decreased after 15 days of storage. The low-fat hamburger patty added with organic olive oil (T2) showed significantly higher pH (p<0.05) compared with other treatments (T1 and T3). The TBARS values of the all treated samples tended to increase after 5 days of storage, and then significant quality loss was observed after 15 days of storage period for the control (T1). However, the samples of the vegitability low-fat patty added organic olive oil had longer shelf-life than the control. The total bacterial counts were 7 log CFU/g after 15 days and 20 days of storage for the control and treatments, respectively. The results of this study showed that the storage period of the treatments was slightly extended compared with the control. Low-fat hamburger patties showed no differences for overall acceptability between control and other patties.

Quality Characteristics of Frozen Welsh Onion (Allium fistulosum L.) according to Various Blanching Treatment Conditions (Blanching 처리 조건에 따른 동결 대파의 품질 특성)

  • Lee, Hye-Ok;Lee, Young-Joo;Kim, Ji-Young;Yoon, Doo-Hyun;Kim, Byeong-Sam
    • Korean Journal of Food Science and Technology
    • /
    • v.43 no.4
    • /
    • pp.426-431
    • /
    • 2011
  • In this study, we set an optimum blanching condition as a pretreatment condition to freeze welsh onion (Allium fistulosum L.) for the purpose of preserving the cooking material for long-term usage. With higher blanching temperature and longer processing time, the Hunter color values and the hardness of welsh onion tended to decrease, which confirmed softening of the tissue. Compared to before blanching, total bacterial counts decreased to near 2 log scale, whereas coliforms were not detected or decreased to a 1-2 log scale. Blanching by heating at 100$^{\circ}C$ for 5 min decreased peroxidase inactivity to more than 94%, whereas only 47% of the inactivity was achieved at 80$^{\circ}C$ for 1 min. The sensory evaluation for the blanched and defrosted welsh onion showed that the group blanched at 80$^{\circ}C$ for 1 min was preferred significantly (p<0.05).

Analysis of Microbial Contamination of Sprouts and Fresh-cut Salads in a Market (유통중인 즉석섭취 새싹채소와 샐러드의 세균오염 분석)

  • Kang, Tae-Mi;Cho, Sung-Kyung;Park, Ji-Yong;Song, Kyung-Bin;Chung, Myung-Soo;Park, Jong-Hyun
    • Korean Journal of Food Science and Technology
    • /
    • v.43 no.4
    • /
    • pp.490-494
    • /
    • 2011
  • Although bacterial outbreaks from ready-to-eat foods have increased, little information is available on microbial quality of sprouts in markets. Fifty sprouts and 30 salads were collected from wholesale markets. Total aerobic count (TAC), coliform, Escherichia coli, and some pathogens were detected. TAC for sprouts was 7.95 log CFU/g and 6.70 for salads, indicating that sprouts were more contaminated by 1 log CFU/g than that of salads. The numbers of coliform were 6.69 log CFU/g for sprouts and 5.42 for salads. E. coli was detected in 16 of 50 sprout samples at 2.38 log CFU/g and eight of 30 salads at 2.21 log CFU/g. Bacillus cereus was detected in 29 of 50 sprout samples and 16 of 30 salads, and the counts were mostly <3 log CFU/g. Salmonella, Staphylococcus aureus, Listeria monocytogenes, Campylobacter jejuni, and Clostridium perfringens were not detected. Therefore, although pathogens may not be a high risk for these foods, the high TAC and E. coli contamination require improved production and distribution methods, particularly for sprouts.

Study on the distribution of marine bacteria and the consumption of oxygen in Wonmun bay (원문만의 해양세균분포와 산소소모량에 관한 연구)

  • PARK Young-Tae;LEE Won-Jae;PARK Joo-Suck;LEE Pil_Yong;KIM Hak-Gyoon
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.24 no.5
    • /
    • pp.303-314
    • /
    • 1991
  • Hypoxic bottom $(\leq2.0ml/l),\;40\%\;oxygen\;saturation)$ is formed in the semi-closed Wonmun bay during summer and autumn early. This study was carried out to know seasonal distribution of marine bacteria and the role of marine bacteria for forming the hypoxic bottom at Wonmun bay during summer and autumn early, 1990. During the study periods, 170 bacterial strains were isolated from sea water and sediment. Viable cell counts were ranged between $10^5-10^7\;cells/ml$. The dominant species were Acinetobacter spp. in spring, Flavobacerium spp. in summer, Pseudomonas spp. in autumn, Serratia spp. in winter. Because ETSA(Electron Transport System Activity) reveals potential consumption of oxygen in the aquatic microorganisms, the ETSA was used as potential consumption of oxygen in this study. The potential consumption of oxygen was in the range of $232.4-637.5{\mu}l/O_2/l/day$ by marine organism and $142.6-432.4{\mu}l/O_2/l/day$ by marine bacteria during the study periods. The ratio of potential oxygen consumption of marine bacteria to total marine microorganism was 0.54. The potential consumption of oxygen by marine bacteria closely related with the number of viable cells. Consequently, bacteria play an important role to form Hypoxic bottom at marine environment.

  • PDF

Quality and Thermoluminescence Properties of ${\gamma}$-Irradiated Boiled-Dried Anchovies during Storage (감마선 조사와 저장 기간에 따른 건멸치류의 품질 및 열발광 특성)

  • 권중호;노정은;변명우
    • Food Science and Preservation
    • /
    • v.9 no.1
    • /
    • pp.19-27
    • /
    • 2002
  • The effect of gamma irradiation was investigated on the microbiological and physicochemical qualities of boiled-dried anchovies (large- and smallsized) packed in PVC film (0.06 ㎜) during storage at 15$\pm$1$\^{C}$ for 6 months. On the other hand, thermoluminescence characteristics of minerals extracted from the sample were analyzed to evaluate its possibility in detecting the irradiated anchovies. The samples were contaminated by microbial levels of 104∼106 CFU/g in total aerobic bacterial counts and negative in coliforms, which were different depending on the sample sizes. Gamma irradiation at 3 kGy was effective for improving the hygienic quality of both samples for 6 months, keeping the microbial population less than 20 CFU/g. Besides it was not detrimental to the quality attributes, such as instrumental color parameters L, a, b, ΔE), browning, TBA value, volatile basic nitrogen, trimethylamine-N and sensory properties(appearance, color, odor, tape, overall acceptability). However, storage conditions (time, temperature, packing) showed a critical factor nfluencing the quality changes of dried anchovies. Thermoluminscence analysis was prove to distinguish irradiated from non-irradiated anchovies by comparing both temperature at which glow curves appear and the curve intensity, that was possible even after 6 months at - 20$\^{C}$.

Changes in the quality of frozen vegetables during storage (저장기간에 따른 동결채소의 품질 변화)

  • Lee, Hye-Ok;Lee, Young-Joo;Kim, Ji-Young;Kwon, Ki-Hyun;Kim, Byeong-Sam
    • Food Science and Preservation
    • /
    • v.20 no.3
    • /
    • pp.296-303
    • /
    • 2013
  • This study was conducted to assess the possibility of preserving frozen vegetables (Aster scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion) for a long period and of using them after such storage by measuring changes in quality due to their preservation. Various freshly harvested vegetables were blanched under optimal conditions (that were determined in a preliminary experiment), quick-frozen at $-40^{\circ}C$ for 24 h, and stored at $-20^{\circ}C$. The change in the chromaticity of the frozen A. scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion did not vary. The hardness of the frozen A. scaber, green pumpkin, Chinese cabbage and Welsh onion did not change during the preservation period, whereas the hardness of the cotyledon and hypocotyl of the soybean sprouts significantly increased on the sixth month of their storage. The total bacterial counts of the A. scaber during the preservation period remained constant at $10^3$ CFU/g, whereas those of soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion decreased slightly to $10^2$ CFU/g. Coliform was not detected in any of the samples. The sensory evaluation showed that the preservation period that was used in this study did not significantly affect the marketability of the frozen vegetables. Therefore, it was considered that A. scaber, soybean sprouts, Chinese cabbage, green pumpkin, and Welsh onion can be safely preserved by freeze-storing them for up to 12 months.

Effect of Irradiation on the Quality of Pale, Soft, Exudative (PSE) Pork During Storage at 4℃ (방사선 조사가 PSE 돈육의 냉장저장 중 품질에 미치는 영향)

  • Jang, Aera;Liu, Xiande;Jo, Cheorun
    • Korean Journal of Agricultural Science
    • /
    • v.34 no.1
    • /
    • pp.67-75
    • /
    • 2007
  • The effect of irradiation on the quality characteristics of pale-soft-exudative (PSE) pork was studied. The pork loin with severe PSE appearance was selected by meat grader,irradiated at 0 and 4.5 kGy, and meat quality characteristics including pH, color, lipid oxidation development, microbial and sensory quality were analyzed during 2 weeks of storage at $4^{\circ}C$. The pH values of non-irradiated and 4.5 kGy-irradiated PSE raw pork loin was not different. Hunter color $a^*$-value, which represents redness of meat surface showed significant increase (P<0.05) in irradiated PSE pork loin. This higher Hunter color $a^*$-value maintained during 2 weeks of storage. By 4.5 kGy of irradiation, approximately 2 log reduction of total aerobic bacterial counts was achieved during 2 weeks of storage when compared with non-irradiated control. Sensory panelists prefer the color of irradiated PSE meat than that of non-irradiated control because of redness. From the results, it is possible to use an irradiation technology to improve not only microbiological safety but also the color of meat which has severe defect such as PSE.

  • PDF

Studies on the Characteristics of Kefir Grains Collected from Korean (한국에서 수집된 케퍼 그레인의 특성에 대한 연구)

  • 박선정;주영철;장윤현;차성관
    • Food Science of Animal Resources
    • /
    • v.23 no.3
    • /
    • pp.262-268
    • /
    • 2003
  • Kefir is a traditional fermented milk in Caucasusian area and is made mainly of milk fermented with lactic acid bacteria and yeasts. Six typical kefir grains were selected from ten kefir grains collected from different locals in Korea. Kefir grains were gelatinous in texture and had various shapes of villi, grapes, leaves, hulled millets, and towels. To investigate predominant microflora of kefir grains, SPC, MRS, M17, Rogosa, and APT agar media were used for viable cell count MRS, SPC, and Rogosa media were most acceptable for bacterial cell counts of the selected kefir grains. From one or two of the SPC agar plates which contained around 25∼50 colonies, all grown colonies were isolated and identified. Most predominant bacteria was identified as Lactobacillus fermentum by API 50 CHL kit. The proportions of Lb. fermentum and Lb. brevis among the total identified bacteria were around 41~88% and M4%, respectively. To select the best preservation method for kefir grains, refrigeration, freezing, and freeze drying were compared. Freeze drying was found most suitable for the preservation of kefir grains, based upon their acid-producing activities and production of off-flavors.