• Title/Summary/Keyword: Microbiological and physicochemical quality

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Effect of the Beet Addition on the Quality of American Preferred Kimchi during Fermentation (비트 첨가가 미국인 선호 김치의 숙성 중 품질에 미치는 영향)

  • Yang, Yu-Jin;Han, Ji-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.4
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    • pp.538-543
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    • 2005
  • To improve the Quality of American preferred kimchi (APK), the APK added different ratios of beets were prepared and the Qualities of those kimchi were investigated by measuring the changes of physicochemical, microbiological and sensory characteristics during fermentation at $5^{\circ}C$. The pH of APK added beet (APKB) decreased as the amount of beet increased while total acidity gradually increased. The reducing sugar content was the highest in APKB added $3\%$ beet at early stage of fermentation. The number of Lactobacillus sp. and Leuconostoc sp. were the highest in $3\%$ beet added group during fermentation. In a texture experiment, the hardness of Korean standard kimchi used as control group showed rapidly decrease while the hardness of APKB were decreased slowly as fermentation proceeded. In Hunter's color values of APKB, lightness and redness increased as the amount of beet increased while yellowness decreased. Sensory scores of overall acceptance, taste, texture and appearance evaluated by Americans as sensory panels were the highest in APKB added $1\%$ beet. Americans also preferred fresh kimchi to optimum ripened kimchi. Therefore it was suggested that the American preferred kimchi added $1\%$ beet was the best group among American preferred kimchi groups.

The Effects of Added Ripened Tomato on the Quality of Baechukimchi (완숙 토마토의 첨가가 배추김치의 품질에 미치는 영향)

  • Moon, Sung-Won;Park, Jung-Eun;Jang, Myung-Sook
    • Journal of the East Asian Society of Dietary Life
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    • v.17 no.5
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    • pp.678-688
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    • 2007
  • In this study, we investigated the effects of ripened tomato on the Baechukimchi fermentation, by measuring sensory, physicochemical, and microbiological properties during fermentation up to 28 days. The Baechukimchi, with various levels [0, 10, 20, 30%(w/v)] of ripened tomato, was fermented at $10^{\circ}C$. The product containing 20% ripened tomato showed the highest scores for overall acceptability, sour taste, texture, sour smell, and color. The intensity characteristic scores related to sour smell and sour taste were the highest in the control, and the texture score was highest in the 20% ripened tomato sample. During fermentation, total acidity increased while pH gradually decreased. The reducing sugar and total vitamin C contents of the experimental groups with added ripened tomato were higher than those of the control. Also, the time periods to reach maximum levels of lactic acid bacteria, by log numbers of cells and total viable cells, were more delayed in the experimental groups with added ripened tomato than in the control. Overall, the results indicate that a 20% addition of ripened tomato to Baechukimchi during fermentation can enhance sensory qualities and extended the palatable period of the product.

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Changes in Quality of Fried Rice with Red Snow Crab Meat Depending on the Storage Period and Temperature (저장기간 및 저장온도에 따른 붉은대게풍미 볶음밥의 품질변화)

  • Jung, Ji Hee;Lim, Ji Hoon;Jeong, Min Jeong;Jeong, In Hack;Kim, Byoung Mok
    • Korean journal of food and cookery science
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    • v.31 no.4
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    • pp.387-394
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    • 2015
  • The red snow crab lives at a depth 200-2,000 m in the east coast. It has a smooth taste with a rich texture. However mostly red snow crab are only utilized materials. For seafood development, research is needed on using red snow crab in various products. In this study, quality changes in fried rice prepared with red snow crab meat, red snow crab emulsion sauce and red snow crab effluent were investigated. Physicochemical, microbiological and sensory characteristics were determined during storage at -20, 4 and $25^{\circ}C$ for 5 weeks to assess changes in the quality of the fried rice. The pH and acidity values did not show any significant differences at $-20^{\circ}C$. The VBN and TBA values of fried rice stored at 4 and $25^{\circ}C$ were significantly higher than those of fried rice stored at $-20^{\circ}C$ during the same storage period. The viable cell count of the fried rice stored at $-20^{\circ}C$ changed little during the storage period. During storage at $25^{\circ}C$, the overall quality was initially 8.0, but rapidly decreased to 1.0 after 5 weeks. In conclusion, the best storage temperature for both quality and safety was $-20^{\circ}C$. The storage condition for instant rice containing red snow crab affects the quality and we confirmed the applicability of using materials from red snow crab.

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.

Standardization of Manufacturing Process and Storage Condition for Pre-processed Foodstuffs (Pre-processed Namul: Peeled Balloon Flower Roots and Parboiled Bracken) (전처리 나물류(깐 도라지, 데친 고사리)의 제조공정 및 유통 중 저장조건의 표준화를 위한 연구)

  • Park, Sunhyun;Noh, Boyoung;Han, Kyujai
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.41 no.11
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    • pp.1611-1618
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    • 2012
  • Peeled balloon flower roots and parboiled bracken are pre-processed foodstuffs commonly used in the institutional food service. This study was conducted to establish the suitable manufacturing process for these foodstuffs and the optimal storage condition during distribution in the market. The most suitable manufacturing process was developed by surveying the manufacturing factories that produce these foodstuffs. Samples were collected by selecting a site among the surveyed manufacturing factories and storing them at different temperatures (4, 10, $20^{\circ}C$). The resulting changes in microbiological, physicochemical, and organoleptic qualities depending on the storage period (1, 2, 3, 4, 5, 7, 10 days) were investigated. The number of general bacteria in balloon flower roots at the beginning of the storage period was 5.26 log CFU/g and the number in the $4^{\circ}C$ storage group remained unchanged until the $3^{rd}$ day, but then increased to 7.63 log CFU/g at the $4^{th}$ day, and then gradually increased up to the $7^{th}$ day. However, in the 10 and $20^{\circ}C$ storage groups, the number was rapidly increased to 7.42 log CFU/g and 7.86 log CFU/g, respectively, at the $2^{nd}$ day. The parboiled bracken samples presented a similar trend. For physicochemical quality changes, the pH and hardness were rapidly decreased in the $20^{\circ}C$ storage group. The organoleptic quality was favorably evaluated (5~6 points out of 9 points) up to the $5^{th}$ day in the $4^{\circ}C$ storage group but the overall acceptability was rapidly decreased from the $2^{nd}$ day in the other storage temperature groups. These results confirmed the optimal storage condition for these pre-processed foodstuffs as being less than 3 days at $4^{\circ}C$.

Effect of Liquid Smoke and Curing Mixture on Quality Characteristics of Chuncheon Dakgalbi during Storage (춘천닭갈비에 훈연액 및 염지제 첨가가 저장 중 품질특성에 미치는 영향)

  • Jeong, Hae Seong;Baek, Ki Ho;Utama, Dicky Tri;Kim, Jun Tae;Lee, Sung Ki
    • Korean Journal of Poultry Science
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    • v.45 no.1
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    • pp.29-39
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    • 2018
  • The goal of the present work was to determine the optimal addition amounts of liquid smoke and curing mixture to develop Chuncheon Dakgalbi with improved preference and shelf-life. In the first experiment, Chuncheon Dakgalbi was prepared with different amounts of liquid smoke. In the second experiment Chuncheon Dakgalbi was prepared with various amounts of curing mixture and 0.1% (w/w) liquid smoke. Different amounts of liquid smoke resulted in different aroma patterns, which were observed using an electronic nose, and Dakgalbi with 0.1% (w/w) liquid smoke had the highest score in overall acceptability. The addition of liquid smoke and curing mixture inhibited the growth of bacteria, slowed down the decline in pH, and delayed increased in volatile basic nitrogen contents and lipid oxidation. However, no clear effects were observed on instrumental color. From a consumer preference test, the highest preference score was achieved by added 0.2% (w/w) curing mixture. Liquid smoke and curing mixture extended shelf-life and improved preference of Chuncheon Dakgalbi. Considering the physicochemical, microbiological and consumer preference, it was recommended to add 0.1% (w/w) liquid smoke and 0.2% (w/w) curing mixture to Chuncheon Dakgalbi to enhance shelf-life and preference.

Characteristics of Rice Doenjang Prepared with Brown Rice Koji (현미코지를 이용한 쌀된장의 특성)

  • Lee, Seung-Eun;Suh, Hyung-Joo;Hwang, Jong-Hyun
    • Food Science and Preservation
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    • v.18 no.6
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    • pp.859-868
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    • 2011
  • This study was conducted to determine the appropriate mixing ratio of Koji and rice Doenjang. Brown rice Doenjang (BR) was prepared with three different ratios of cooked soybean to brown rice Koji [1.5:1 (BR-1); 2:1 (BR-2); and 3:1 (BR-3)], and polished-rice Doenjang (PR) was prepared with cooked soybean and polished-rice Koji (2:1). The components related to the quality of Doenjang were analyzed during 60-day aging. No significant differences were found in the moisture and salt contents between the brown rice Doenjang and the polished-rice Doenjang. The pH, titratable acidity, and bacteria cells increased at 20-30 days aging time, and decreased thereafter. The reducing-sugar and ethyl alcohol contents, on the other hand, increased at 10-20 days previously. These analytical values of the physicochemical and microbiological characteristics increased with the increase in the percentage of koji in each Doenjang. The amino-nitrogen and free-amino-acid contents showed the highest levels in BR-1: 887.6 and $4047.0{\pm}1.5$ mg%, respectively. The ${\gamma}$-aminobutyric-acid (GABA) contents slightly increased with increasing aging time. In the color of Doenjang, the lightness and yellowness increased along with the aging time, but the redness decreased as the aging time increased. These results showed that BR-1 processed the fermentation the fastest compared with the others. Moreover, the reducing-sugar, ethanol, and free-amino-acid contents as palatable components increased rapidly until 30 days aging time.

Novel Molecular-Based Approaches for Analyzing Microbial Diversity in Raw-Milk Long-Ripened Cheeses: A Review (비살균 숙성 치즈의 미생물균총 분석에 이용되는 새롭게 개발된 분자생물학적 방법: 총설)

  • Kim, Dong-Hyeon;Chon, Jung-Whan;Kim, Hyunsook;Lee, Soo-Kyung;Kim, Hong-Seok;Lee, Joo-Yeon;Yim, Jin-Hyuk;Song, Kwang-Young;Kim, Young-Ji;Kang, Il-Byung;Jeong, Dana;Park, Jin-Hyeong;Jang, Ho-Seok;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.34 no.1
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    • pp.9-20
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    • 2016
  • Various microflora, including lactic acid bacteria, are important and necessary components of various cheeses and have significant roles in cheese manufacturing and ripening. In general, the starter culture and secondary microflora could affect the physicochemical properties of various cheeses and could contribute to modifications during manufacturing and ripening. Therefore, during cheese manufacturing and ripening, microbial diversity may depend on continuous interactions among microflora and various environmental conditions. The microbial diversity of cheese is very complex and difficult to control using the classical microbiological techniques. However, recent culture-independent methods have been rapidly developed for microflora in cheese, which could be directly detected using DNA (and/or RNA) in combination with culture-dependent methods. Therefore, this review summarizes state-of-the-art molecular methods to analyze microbial communities in order to understand the properties that affect quality and ripening as well as the complex microbial diversity of various raw-milk, long-ripened cheeses.

Studies on the Improvement of Quality and Shelf-life of Traditional Marinated Beef(Galbi) as Affected by Packaging Method during Storage at$-1^{\circ}C$ (포장방법에 따른 전통 양념갈비의 품질 및 저장성 개선에 관한 연구)

  • Kim, Cheon-Jei;Jeong, Jong-Yon;Lee, Eui-Soo;Song, Hyun-Ho
    • Korean Journal of Food Science and Technology
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    • v.34 no.5
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    • pp.792-798
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    • 2002
  • Investigations on the microbiological, physicochemical, and sensory characteristics of seasoned Galbi using various packaging methods during storage at $-1^{\circ}C$ revealed no significant differences in pH values and acidities of seasoned Galbi depending on packaging methods and storage periods. Increments of thiobarbituric acid values of seasoned Galbi with non-evacuated packaging and modified atmosphere packaging were superior to those of vacuum packaging and double-film vacuum packaging during storage. Seasoned Galbi with non-evacuated packaging showed the highest volatile basic nitrogen value, and total plate count significantly increased compared to other packaging methods after 15 days storage. Coliform bacteria showed an average count of 2.35 log CFU/g at the beginning of storage, which increased slightly from 7 to 15 days, and was maintained under 4.0 log CFU/g after 15 days storage. The sensory evaluation revealed that non-evacuated packaging scored relatively lower than other methods in color, flavor, off-odor, and overall acceptability after storage.

Quality and shelf life of sliced root of Platycodon grandiflorum treated by ozon-microbubble-heat shock (오존-마이크로버블-열수 처리한 세절 도라지의 품질 및 저장성)

  • Park, Kyung Min;Lee, Ji Young;Min, So-Ra;Jeong, Moon-Cheol;Koo, Minseon
    • Food Science and Preservation
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    • v.23 no.5
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    • pp.605-613
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    • 2016
  • The quality and shelf life of sliced root of Platycodon grandiflorum (Doraji) treated by ozon-microbubble-heat shock (OMH) were investigated by combining modified-atmosphere packaging [MAP, ($50%O_2+15%CO_2+35%N_2$)]. The study was based on microbiological (total viable bacteria, fungi, Enterobacteriaceae and coliforms numbers), physicochemical and sensory changes. OMH treatment was effective in reducing microbial populations of the sliced Doraji, especially Enterobacteriaceae and coliforms reduced by 2 log CFU/g. However OMH-MAP treatment remained the aerobe and fungi numbers. Regarding the color, OMH-MAP delayed the change of Hunter $b^*$ and the sliced Doraji by OMH-MAP treatment exhibited lower decrease of flavor and overall acceptability compared to those by polypropylene packaging after tap water treatment (Control). The OMH and $50%O_2+15%CO_2$ MAP treatment gave better sensory quality and extended shelf-life for sliced Doraji (~3 days longer shelf-life than Control). Flavor was significantly related to overall acceptability at both Control and OMH-MAP, whereas total coliforms prevalence was associated with overall acceptability at only OMH-MAP. Therefore microbubble-heat shock treatment may improve microbial safety and sliced Doraji by OMH treatment can stored under $50%O_2+15%CO_2$ treatment for up to 7 days. Thus, OMH and MAP treatment may be used in maintaining the storage quality and marketability of sliced Doraji.