• Title/Summary/Keyword: microbiological quality changes

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Fermentation of Kanjang, Korean Soy Sauce, in Porosity-Controlled Earthenwares with Changing the Mixing Ratio of Raw Soils (흙배합비를 달리하여 기공율이 조절된 담금용기 항아리에서의 간장 발효)

  • Chung, Sun-Kyung;Lee, Kwang-Soo;Lee, Dong-Sun
    • Korean Journal of Food Science and Technology
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    • v.38 no.2
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    • pp.215-221
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    • 2006
  • This study focuses on investigating the effect of porosity-controlled earthenware on fermentation of kanjang, Korean soy sauce. Porosity of fermentation vessel was controlled by changing the mixing ratio of raw soils at manufacturing earthenware. Earthenwares contented 0%, 40% and 60% of the mixture of red brown soil and powdered soil (1 : 1), respectively. The more contents of the mixed soil, the more porosity in earthenware. During fermentation of kanjang in porosity-controlled earthenwares at $30^{\circ}C$ for 4 months, physical, chemical, microbiological and sensory quality attributes were monitored. Compared to other containers, kanjang in the earthenware that had 0% mixed soil showed less water loss, salt content and pH. It also produced higher total acidity, protease activity, total nucleotide, and microbiological changes which included total aerobic bacteria, lactic acid bacteria and yeast. Total nitrogen and free amino acids in kanjang did not show the consistency with the mixed soil contents of fermentation containers, which may take more effect of other factors as water loss than the porosity of vessels. However, the percentage of glutamic acid in total free amino acids was a little higher in the earthenware that had 0% of mixed soil than other containers. These positive physicochemical, microbiological changes also resulted in higher sensory quality.

Effects of 27.12 MHz Radio Frequency on the Rapid and Uniform Tempering of Cylindrical Frozen Pork Loin (Longissimus thoracis et lumborum)

  • Choi, Eun Ji;Park, Hae Woong;Yang, Hui Seon;Kim, Jin Se;Chun, Ho Hyun
    • Food Science of Animal Resources
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    • v.37 no.4
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    • pp.518-528
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    • 2017
  • Quality characteristics of frozen cylindrical pork loin were evaluated following different tempering methods: 27.12 MHz curved-electrode radio frequency (RF) at 1000 and 1500 W, and forced-air convection (FC) or water immersion (WI) at $4^{\circ}C$ and $20^{\circ}C$. The developed RF tempering system with the newly designed curved-electrode achieved relatively uniform tempering compared to a parallel-plate RF system. FC tempering at $4^{\circ}C$ was the most time-consuming process, whereas 1500 W RF was the shortest. Pork sample drip loss, water holding capacity, color, and microbiological quality declined after WI tempering at $20^{\circ}C$. Conversely, RF tempering yielded minimal sample changes in drip loss, microstructure, color, and total aerobic bacteria counts, along with relatively uniform internal sample temperature distributions compared to those of the other tempering treatments. These results indicate that curved-electrode RF tempering could be used to provide rapid defrosting with minimal quality deterioration of cylindrical frozen meat block products.

Efficacy of Flaxseed Flour as Bind Enhancing Agent on the Quality of Extended Restructured Mutton Chops

  • Sharma, Heena;Sharma, Brahma Deo;Mendiratta, S.K.;Talukder, Suman;Ramasamy, Giriprasad
    • Asian-Australasian Journal of Animal Sciences
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    • v.27 no.2
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    • pp.247-255
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    • 2014
  • Consumers have become very conscious about their nutrition and well being due to changes in their socio-economic lifestyle and rapid urbanization. Therefore, development of technology for production of low cost and functional meat products is urgently required. One such approach is innovative restructuring technology in which binding of meat pieces still remains the main challenge and extension of product is generally associated with poor binding and texture. Thus, the present study was envisaged as an attempt to solve this problem by the incorporation of flaxseed flour (FF) as bind enhancing agent. The FF was used at three different levels viz., 0.5%, 1%, and 1.5% to replace lean meat in pre-standardized restructured mutton chops formulation. The products were subjected to analysis for physico-chemical, sensory and textural properties. Cooking yield, moisture percentage and fat percentage increased with increase in the level of incorporation of FF, however, protein percent and pH decreased with increase in the level of incorporation. Shear force value of product incorporated with 1.5% FF was significantly higher (p<0.01) than control and product containing 0.5% FF level. Among the sensory attributes, product with 1% flaxseed flour showed significantly higher values (p<0.05) for general appearance, binding, texture and overall acceptability. Hardness showed significant increasing (p<0.01) values with increasing levels of incorporation of flaxseed flour, however all other parameters of texture profile analysis showed a decreasing trend. On the basis of sensory scores and physico-chemical properties, the optimum incorporation level of FF was adjudged as 1%. Products incorporated with optimum level of flaxseed flour (1%) were also assessed for water activity and microbiological quality during the storage period of 15 days. It was found that the extended restructured product could be safely stored under refrigeration ($4^{\circ}C{\pm}1^{\circ}C$) in low density polyethylene (LDPE) pouches for 15 days without marked deterioration in sensory and microbiological quality. Thus, it was concluded that flaxseed flour can be used as a good bind enhancing agent in extended restructured meat products at an economic cost.

Quality Changes of Kimchi Manufactured with Sanitized Materials by Ozone and Gamma Irradiation during Storage (오존 및 방사선 조사기술 이용 원부재료의 위생화 후 제조한 김치의 저장기간에 따른 변화)

  • Lee, Kyong-Haeng;Byun, Myung-Woo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.2
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    • pp.216-221
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    • 2007
  • Microbiological, chemical and sensorial quality changes of kimchi, which was manufactured with sanitized materials by ozone and gamma irradiation, were investigated during storage. The number of total aerobic bacteria in control was increased rapidly by storage and decreased after 10 days of storage. However, the kimchi which was manufactured with materials treated with ozone or gamma irradiation showed a lower rate of increase. The number of lactic acid bacteria was lower in control than in treatments. Gamma irradiation of 3 or 5 kGy showed the lowest change of microbial population in kimchi during storage. pH, acidity and sensory quality were also rapidly changed in control whereas those of ozone or irradiation treated sample was slower. Therefore, cold pasteurization of materials before kimchi manufacturing provide a slower fermentation, resulting into the extension of storage quality for kimchi.

Storage Stability of Vacuum-packaged Dry-aged Beef during Refrigeration at 4℃

  • Kim, Seonjin;Lee, Hyun Jung;Kim, Minsu;Yoon, Ji Won;Shin, Dong Jin;Jo, Cheorun
    • Food Science of Animal Resources
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    • v.39 no.2
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    • pp.266-275
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    • 2019
  • Although the production of dry-aged beef has been increasing, most purveyors are unaware of the changes in quality that ensue after completion of the aging period and do not adhere to specific guidelines for its packaging and storage. The objective of this study was to investigate the storage stability of vacuum-packaged dry-aged beef based on changes in microbial, physicochemical, and sensory properties during refrigeration at $4^{\circ}C$ for 21 d. The total aerobic bacterial count exceeded 6 Log CFU/g at approximately day 11 and significantly increased after day 14. Freshness indicators such as pH and volatile basic nitrogen content were acceptable until day 14 and 21, respectively. Based on the evaluation of overall sensory acceptability, the dry-aged beef was acceptable until 14 d without any sensory deterioration. Therefore, vacuum-packaged dry-aged beef could be stored for 11 d at $4^{\circ}C$ without any adverse effect on its microbial and sensory quality.

Experimental Studies on the Optimum Pasteurization Condition of the Cow's Milk Produced in Korea II. The Changes in Chemical Composition and Microbiological Aspects of Low Temperature Pasteurized Milk (한국산(韓國産) 우유(牛乳)의 적정(適正) 살균조건(殺菌條件)에 관(關)한 실험적(實驗的) 연구(硏究) II. 저온살균처리(低溫殺菌處理)에 의한 우유(牛乳)의 화학적(化學的) 조성(組成) 및 미생물학적(微生物學的) 성상(性狀)의 변화(變化))

  • Kim, Jong Woo
    • Korean Journal of Agricultural Science
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    • v.14 no.2
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    • pp.301-308
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    • 1987
  • The results of experiment to find out the optimum pasteurization condition by heating from $50^{\circ}C$ to $70^{\circ}C$ at intervals of $5^{\circ}C$ and to review chemical composition, microbiological aspects and keeping quality were summarized as follows: 1. The milk sample pasteurized at $50-70^{\circ}C$ showed the decreased pH value from 6.55 to 6.42 while the contents of protein, fat, lactose and ash did not have significant changes. 2. Non-casein nitrogen and filterable nitrogen decreased while casein nitrogen and non protein nitrogen increased as the heat treatment increased. 3. The content of calcium and vitamin C decreased and artificial digestibility for the pasteruized milk increased from 14.07% to 20.00% by the heat treatment. 4. Milk pasteurized at $65^{\circ}C$ had viable bacteria counts $1.3{\times}10^4/m{\ell}$, coliforms negative, psychrotrophic bacteria $9.5{\times}10^2/m{\ell}$ and 99.0% pasteurization effect. 5. Milk pasteurized at $65^{\circ}C$ did not show significant changes in chemical composition and microbiological aspects at $4^{\circ}C$ in refrigerator.

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Microbiological Characteristics of Alcoholfermenting Wild Yeast, Aureobasidium pullulans P-1 and Its Makgeolli Fermentation Characteristics (알코올 발효성 야생 효모, Aureobasidium pullulans P-1의 균학적 특성과 막걸리 발효 특성)

  • Hong, Yong-Cheol;Han, Sang-Min;Lee, Jong-Soo
    • The Korean Journal of Mycology
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    • v.46 no.3
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    • pp.307-314
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    • 2018
  • The goal of this study was to investigate the microbiological characteristics of the ethanol-producing wild yeast, Aureobasidium pullulans P-1, isolated from flowers growing near the Yedang reservoir, Chungnam province, Korea, and in addition, to optimize its fermentation ability for the production of Makgeolli. A. pullulans P-1 was oval-shaped, and formed ascospores and pseudomycelium. The P-1 strain was a halophilic and sugar tolerant yeast which grew in 15% NaCl and 50% glucose-containing yeast extract-peptone-dextrose media. The P-1 strain was also resistant to 20% ethanol. Changes of the physicochemical properties during Makgeolli fermentation by A. pullulans P-1 were investigated. A maximum of 8.45% ethanol was obtained when a mixture of cooked rice, 150% water, and 35% ipguk per cooked rice was fermented by 5% A. pullulans P-1 culture broth at $25^{\circ}C$ for 10 days. Antihypertensive angiotensin I-converting enzyme inhibitory activity in the Makgeolli ferment produced by A. pullulans P-1 reached a high of 71.1% after 10 days.

Effect of Powder-type Dried Alaska Pollack Addition on the Quality of Kimchi (북어 가루 첨가가 김치의 품질특성에 미치는 영향)

  • 이하영;백재은;한영실
    • Korean journal of food and cookery science
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    • v.19 no.2
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    • pp.254-262
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    • 2003
  • Powder-type dried pollack was added to Kimchi, the groups were stored at 4$^{\circ}C$, respectively, physicochemical, microbiological, and sensory properties of the Kimchi were examined according to the stored durations. The pH appeared to have almost similar values in the early stages of the fermentation. Generally, the groups with the additional powder-type dried Pollack had high pHs in the later stages of the fermentation. For the changes in the acidity, until the optimum edible period was reached, the groups with the additional powder-type dried Pollack required longer than those groups with additional fluid anchovy sauce. With regard to the salinity, there were no significant differences between the respective groups. For changes with regard to the reducing sugar, from the early to late fermentation stages, the greatest content was shown in the no additional protein source group, however, after the optimum edible period, there were no significant differences between the treated groups. In the case of free amino acids, the total quantities of Serine, Glycine, Threonine, Proline and Alanine, which all have a sweet taste, were usually found to have increased too almost twice those in the control groups, on the addition of 0.80% powder-type dried Pollack to the Kimchi. As a result of examining the microbiological properties, the time spent reaching the maximum numbers was longer in the additional powder-type dried Pollack groups. Similarly, the maximum numbers of lactic acid bacteria also appeared at the same time, but the difference between the treated groups was small, compared with the total numbers of microorganisms. As a result of the sensory evaluation, the treated groups generally gained better evaluations for several items. corresponded to the addition of 0.65% powder-type dried Pollack.

Development of Washing System for Improving Microbiological Quality of Blueberry after Postharvest (수확 후 블루베리의 미생물학적 품질향상을 위한 세척시스템 개발)

  • Chun, Ho Hyun;Park, Seok Ho;Choi, Seung Ryul;Song, Kyung Bin;Park, Seung Jong;Lee, Sun Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.11
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    • pp.1886-1891
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    • 2013
  • To inactivate the microorganisms on the surface of blueberries after harvest and to secure microbial safety, a bubble-aqueous chlorine dioxide washing system was developed. After treating the freshly prepared blueberries with the bubble-aqueous chlorine dioxide washing system, the changes in the microbial populations and quality of the blueberries were determined during storage $4{\pm}1^{\circ}C$. Microbiological data indicated that the populations of total aerobic bacteria, yeast and mold decreased by 1.4 and 1.3 log CFU/g at the treatment of 20 ppm aqueous chlorine dioxide with the system, respectively. There was no significant difference in color change and weight loss during storage among treatments. In addition, this washing system could handle approximately 60 kg of blueberry per hour, resulting in labor-saving. Therefore, these results clearly suggest that the bubble-aqueous chlorine dioxide washing system could be useful in improving the microbiological safety of fresh blueberries after harvest.

Changes of Quality Characteristics of Salt-Fermented Shrimp Prepared with Various Salts (소금 종류에 따른 새우젓의 품질 특성 변화)

  • Cho, Sun-Duk;Kim, Gun-Hee
    • The Korean Journal of Food And Nutrition
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    • v.23 no.3
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    • pp.291-298
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    • 2010
  • We has been researched physicochemical, sensory and microbiological characteristics of salt-fermented shrimps after making them with different kinds of salts such as domestic or imported and purified or solar salt. Physicochemical characteristics of salt-fermented shrimps on color, salinity and pH which was made by 6 kinds of salt did not show any difference in the overall processing. However, in case of amino-N content, it showed the higher level of its contents at the process of Korean solar salt comparing to other. In case of microbiological, the total viable cells was detected most from the Australian solar salt during the initial stage of fermentation, but after 12-week of fermentation, the Chinese solar salt showed the largest number of total viable cells. Also, it found the Korean solar salt contained the lowest level of coliforms, while it found the highest level of coliforms contents in Chinese solar salt. However, there were no significant differences of microbiological characteristics from the salt-fermented shrimp made with 6 kinds of salt(p<0.05). As a result of sensory quality on salt-fermented shrimps, domestic salts was higher than imported. But there were no significant difference of sensory quality from the salt-fermented shrimps made with 6 different kinds of salt(p<0.05).