• Title/Summary/Keyword: physicochemical qualities

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Influences of Fish Farm on the Physicochemistry of Stream Water Quality in (Mt.) Paekun Area(II) (백운산 지역에서 계류수의 이화학적 성질에 미치는 양어장의 영향(II))

  • Park, Jae-Hyeon;Woo, Bo-Myeong;Kim, Oue-Ryong;Ahn, Hyun-Chul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.4 no.1
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    • pp.32-40
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    • 2001
  • Quantifications of fish farm influences on stream water quality may provide basic informations on watershed management to reduce environmental impact due to fish farm development and to conserve stream water quality in forested watershed area. In this research stream water qualities around Mt. Paekun area were monitored seasonally and the following results were obtained. Due to the increase of pH in effluent water from the fish farm it was believed that alkalization of stream water can be accelerated by large scale development of fish farms in the forested watershed area. Negative effects on stream water quality were observed by indications of increase in electrical conductivity and temperature of effluent water from the fish farm. Decreases in physicochemical indices such as the amount of dissolved oxygen, percentage of dissolved oxygen, total amount of cation, total amount of anion and total amount of ion in effluent water from the fish farm were also negative aspects in downstream ecology. It is recommended that water purification system as well as eco-friendly fish farm design should be incorporated to large scale fish farm development plan in forested watershed area.

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Influences of Fish Farm Development on the Physicochemistry of Stream Water Quality in (Mt.) Paekun Area (백운산 지역에서 계류수의 이화학적 성질에 미치는 양어장 개발의 영향)

  • Park, Jae-Hyeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.2 no.3
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    • pp.54-63
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    • 1999
  • Quantifications of fish farm influences on stream water quality may provide basic informations on watershed management to reduce environmental impact due to fish farm development and to conserve stream water quality in forested watershed area. In this research stream water qualities around (Mt.) Paekun area were monitored by seasons and the following results were obtained. Due to the increase of pH in effluent water from the fish farm it was believed that alkalization of stream water can be accelerated by large scale development of fish farms in the forested watershed area. Negative effects on stream water quality was also observed by indications of increase in electrical conductivity and temperature of effluent water from the fish farm. Decreases of physicochemical indexes such as the amount of dissolved oxygen, percentage of dissolved oxygen and total amount of ion in effluent water from the fish farm were also negative aspects in downstream ecology. It is recommended that water purification system as well as eco-friendly fish farm design be incorporated to large scale fish farm development plan in forested watershed area.

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Effect of dried Hovenia dulcis fruit powder on quality characteristics and antioxidant properties of cookies

  • Park, Bo Ram;Choi, Ji Eun;Lee, Jun Ho
    • Food Science and Preservation
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    • v.24 no.4
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    • pp.517-523
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    • 2017
  • Hovenia dulcis fruit powder (HFP) has shown diverse functional activities; thus, it is rational to incorporate HFP into suitable food products with enhanced nutritional and functional quality, and their incorporation into bakery products such as cookies could be a good alternative for the increase of consumption. The aim of this study was to examine the effect of HFP addition on the quality characteristics of cookies. The pH of cookie doughs ranged from 5.80-6.34, with no remarkable differences by HFP addition. Density of cookie doughs significantly decreased upon addition of HFP (p<0.05), but there were no significant differences among samples added with HFP (p>0.05). Moisture content and spread factor of cookies significantly increased with higher content of HFP in the formulation (p<0.05). For color values of cookie surface, $L^*$ and $b^*-values$ decreased while $a^*-value$ increased as a result of HFP substitution (p<0.05). 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activities were significantly increased (p<0.05) with higher substitution of HFP, showing a positive correlation. Hedonic sensory results indicated that cookies supplemented with 4% HFP received the most favorable acceptance scores for sensory attributes. Overall, HFP-added cookies could be developed with improved physicochemical qualities without sacrificing consumer acceptability.

Physicochemical Factors Affecting Cooking and Eating Qualities of Rice and the Ultrastructural Changes of Rice during Cooking (쌀의 취반 및 식미특성에 영향을 주는 요인들과 취반 시 쌀의 배유 조직의 변화)

  • 이영은;오스만엘리자베쓰엠
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.20 no.6
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    • pp.637-645
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    • 1991
  • Physicochemical factors affecting cooking and eating quality of rice and their mechanisms were investigated. The stickiness of cooked rice was negatively correlated with amylose content(r=0.58, p<0.05) and protein content(r=-0.72, p<0.01), but not affected by crude fat content of rice. The ultrastructure of cooked rice grain showed the progressive gelatinization of starch from the periphery toward the center of the endosperm as water and heat energy diffused into. The rate of water diffusion appears to be dependent on the cell arrangement in the endosperm and the protein content of milled rice. Once water and heat reach the starch granules, the rate of in situ gelatinization of starches appears to be dependent on their own gelatinization temperature range and amylose content. Protein acts as a barrier for the swelling of starch and water diffusion in two ways : 1) by encasing starch granules in the starchy endosperm, and 2) by forming a barrier between the subaleurone layer and the starchy endosperm. Therefore, the separation and fragmentation of the outermost layers of the endosperm occurred more easily in the low-protein content rices, and was associated with increases of solids lost in cooking-water at 95$^{\circ}C$ and stickiness of cooked rice.

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Effects of Pressure Assisted Freezing on Physicochemical Properties of Pork (Pressure Assisted Freezing이 돈육의 이화학적 특성에 미치는 효과)

  • Hong, Geun-Pyo;Ko, Se-Hee;Choi, Mi-Jung;Min, Sang-Gi
    • Food Science of Animal Resources
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    • v.27 no.2
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    • pp.190-196
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    • 2007
  • This study was carried out to investigate the effects of pressure assisted freezing(PAF) on physicochemical properties of pork meat. Pork meat was frozen under pressure up to 200 MPa at $-60^{\circ}C$, and compared with fresh control. Phase transition temperature decreased with increasing pressure level, while pressure level had no effect on supercooling extent. Increasing pressure level increased pH of meat significantly(p<0.05). Thawing losses of all treatments were significantly higher(p<0.05) than control with the exception of PAF at 200 MPa. Water holding capacity(WHC) was increased significantly(p<0.05) with increasing pressure level up to 100 MPa. Cooking loss tended to decrease with increasing pressure level. In color, CIE $L^*-\;and\;b^*-value$ increased with increasing pressure level, while CIE $a^*-value$ decreased significantly(p<0.05). Increasing pressure level up to 150 MPa increased shear force significantly(p<0.05), however, no significant difference between 150 and 200 MPa in shear force was found(p>0.05). Therefore, the results indicated that excessive pressure level in PAF caused several losses in meat qualities, while PAF at mild pressure level improved meat qualities compared to atmosphere freezing.

Quality and Acceptability of Meat Nuggets with Fresh Aloe vera Gel

  • Rajkumar, V.;Verma, Arun K.;Patra, G.;Pradhan, S.;Biswas, S.;Chauhan, P.;Das, Arun K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.5
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    • pp.702-708
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    • 2016
  • Aloe vera has been used worldwide for pharmaceutical, food, and cosmetic industries due to its wide biological activities. However, quality improvement of low fat meat products and their acceptability with added Aloe vera gel (AVG) is scanty. The aim of this study was to explore the feasibility of using fresh AVG on physicochemical, textural, sensory and nutritive qualities of goat meat nuggets. The products were prepared with 0%, 2.5%, and 5% fresh AVG replacing goat meat and were analyzed for proximate composition, physicochemical and textural properties, fatty acid profile and sensory parameters. Changes in lipid oxidation and microbial growth of nuggets were also evaluated over 9 days of refrigerated storage. The results showed that AVG significantly (p<0.05) decreased the pH value and protein content of meat emulsion and nuggets. Product yield was affected at 5% level of gel. Addition of AVG in the formulation significantly affected the values of texture profile analysis. The AVG reduced the lipid oxidation and microbial growth in nuggets during storage. Sensory panelists preferred nuggets with 2.5% AVG over nuggets with 5% AVG. Therefore, AVG up to 2.5% level could be used for quality improvement in goat meat nuggets without affecting its sensorial, textural and nutritive values.

Relationships between Descriptive Sensory Attributes and Physicochemical Analysis of Broiler and Taiwan Native Chicken Breast Meat

  • Chumngoen, Wanwisa;Tan, Fa-Jui
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.7
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    • pp.1028-1037
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    • 2015
  • Unique organoleptic characteristics such as rich flavors and chewy texture contribute to the higher popularity of native chicken in many Asian areas, while the commercial broilers are well-accepted due to their fast-growing and higher yields of meat. Sensory attributes of foods are often used to evaluate food eating quality and serve as references during the selection of foods. In this study, a three-phase descriptive sensory study was conducted to evaluate the sensory attributes of commercial broiler (BR) and Taiwan native chicken (TNC) breast meat, and investigate correlations between these sensory attributes and instrumental measurements. The results showed that for the first bite (phase 1), TNC meat had significantly higher moisture release, hardness, springiness, and cohesiveness than BR meat. After chewing for 10 to 12 bites (phase 2), TNC meat presented significantly higher chewdown hardness and meat particle size, whereas BR meat had significantly higher cohesiveness of mass. After swallowing (phase 3), TNC meat had higher chewiness and oily mouthcoat and lower residual loose particles than BR meat. TNC meat also provided more intense chicken flavors. This study clearly demonstrates that descriptive sensory analysis provides more detailed and more objectively information about the sensory attributes of meats from various chicken breeds. Additionally, sensory textural attributes vary between BR and TNC meat, and are highly correlated to the shear force value and collagen content which influence meat eating qualities greatly. The poultry industry and scientists should be able to recognize the sensory characteristics of different chicken meats more clearly. Accordingly, based on the meat's unique sensory and physicochemical characteristics, future work might address how meat from various breeds could best satisfy consumer needs using various cooking methods.

Quality Stability of Spinach Powder As Influenced by Microbial Decontamination Treatment (시금치 분말의 품질안정성에 대한 살균처리의 영향)

  • Kwon, Joong-Ho;Byun, Myung-Woo;Cho, Han-Ok;Choi, Jong-Uck
    • Korean Journal of Food Science and Technology
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    • v.26 no.2
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    • pp.167-171
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    • 1994
  • With a view to improving microbiological quality of spinach powder which is currently used for convenience food production, comparative efficacy of ethylene oxide(EO) fumigation and gamma irradiation was investigated by determining microbial populations and physicochemical quality for treated samples. Spinach powder was contaminated with various microorganisms ranging from $10^{2}/g\;to\;10^{4}/g$, which composed of thermophiles, acid tolerant bacteria, fungi, coliforms, etc. Microorganisms contaminated were destroyed up to undetected levels by gamma irradiation at below 7 kGy. showing the radiosensitivity $D_{10}$ 2.93 kGy on total aerobic bacteria. Ethylene oxide fumigation, however. was found unsatisfactory for physicochemical quality as well as microbial decontamination of the sample. It has been generally observed that influence of optimum-dose range of irradiation on the physicochemical qualities was insignificant, which was proved in the organoleptic evaluations on the stored sample.

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Changes in Physicochemical Characteristics of Mature-Green Mume (Prunus mume Sieb. et Zucc) Fruits as Influenced by the Thickness of Packaging Material (포장재 두께에 따른 청매실의 이화학적 특성 변화)

  • 차환수;정명수
    • Food Science and Preservation
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    • v.9 no.2
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    • pp.148-153
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    • 2002
  • Effect of the thickness of low density polyethylene(LDPE) Film as packaging material on changes in physicochemical characteristics of mature-green mume (Prunus mume Sieb. et Zucc) fruits during storage at different temperatures(0, 10 and 25$\^{C}$) were investigated. Fruit samples stored in pouches with 30㎛ thickness of LDPE film maintained well not only external qualities such as Shape and firmness, but also internal chemical properties such as pH, acidity, the content of soluble solid and chlorophyll, and color, comparing with samples stored without packaging material or in other pouches with different film thickness(20 and 40㎛). From the results, it was found that the maintenance of quality of mature-green mume fruits during storage at 0, 10 and 25$\^{C}$ closely related to the changes in respiratory conditions for fruits affected by the film thickness of the packaging material.

Applying Vinegar as a Disinfectant for Lettuce in Foodservice Operations;A Focused Evaluation of Its Physiological and Sensory Characteristics Effects (단체급식 및 외식업체에서 이용되는 양상추의 식초수 소독의 적용을 위한 연구;이화학적 특성 및 관능적 특성 분석을 중심으로)

  • Kim, Heh-Young;Kim, Hyun-Jung
    • Korean journal of food and cookery science
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    • v.24 no.2
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    • pp.228-235
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    • 2008
  • In this study, vinegar disinfection was evaluated as a novel method for the preparation of raw food ingredients used in foodservice operations. The test materials were washed and disinfected using three different methods, and were then stored at temperatures of $3^{\circ}C\;and\;10^{\circ}$ for 7 days; Following storage, physicochemical and sensory characteristic comparisons were performed. Temperature for all test materials ranged between 15.2-20. $9^{\circ}C$, water activity was maintained near 0.96, and the pH levels of the samples were 6.44, 6.29, and 6.35, respectively. Residual chlorine levels were generally low, ranging between 0.01 and 0.02. The physicochemical qualities of the samples were evaluated according to the storage method and temperature. Brightness(L value), redness(a value), and yellowness(b value) tended to increase with increasing storage time. The evaluated sensory characteristics included appearance, color, smell, taste, texture, and overall acceptance. With regard to storage temperature the vinegar-treated samples were evaluated as superior, receiving a score of 7.00, and the ingredients stored at $3^{\circ}C$ were evaluated as significantly (p< 0.001) superior to those stored at $10^{\circ}C$. Overall, vinegar is an effective disinfectant to apply in the preparation of raw vegetables that are typically served without heating, and which can cause serious food safety issues when contaminated.