• 제목/요약/키워드: physicochemical qualities

검색결과 212건 처리시간 0.027초

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

  • 박재현;우보명;김우룡;안현철
    • 한국환경복원기술학회지
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    • 제4권1호
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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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백운산 지역에서 계류수의 이화학적 성질에 미치는 양어장 개발의 영향 (Influences of Fish Farm Development on the Physicochemistry of Stream Water Quality in (Mt.) Paekun Area)

  • 박재현
    • 한국환경복원기술학회지
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    • 제2권3호
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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
    • 한국식품저장유통학회지
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    • 제24권4호
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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.

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

  • 이영은;오스만엘리자베쓰엠
    • 한국식품영양과학회지
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    • 제20권6호
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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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Pressure Assisted Freezing이 돈육의 이화학적 특성에 미치는 효과 (Effects of Pressure Assisted Freezing on Physicochemical Properties of Pork)

  • 홍근표;고세희;최미정;민상기
    • 한국축산식품학회지
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    • 제27권2호
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    • pp.190-196
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    • 2007
  • 본 실험은 압력 수준에 따른 PAF이 돈육의 이화학적 특성에 미치는 효과를 규명하고자 시도되었다. 비록 가압 수준기 증가에 따른 상전이 온도와 냉각온도간의 차이 감소에 기인하여 고압 하에서의 잠열 감소에 의한 동결 속도 증가의 효과는 얻을 수 없었지만, 육의 PAE 처리는 가압처리에서와 같이 보수력 및 육즙 손실을 대기압 동결 처리보다 더욱 현저하게 줄일 수 있었다. 그러나 지나친 가압은 육 단백질간의 aggregation 및 심한 변성에 기인하여 육의 연도를 저하시키는 결과를 초래하였고, 또한 소비자의 구매와 직접적으로 관련된 색도에 악영향을 끼친 것으로 판단되었다. 그러나 상대적으로 낮은 압력 범위 조건에서의 PAF 처리는 동결 시 고압 처리에 의한 육색 저하를 최소화 할 수 있었고, 전단력 측면에서도 대기압 동결처리와 유의적인 차이를 보이지 않을 뿐만 아니라 보수력을 향상시킴으로써 동결처리보다 더 큰 잠재적인 이점을 보였고, 이 부분에 대한 더 많은 연구가 필요할 것으로 판단된다.

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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    • 제29권5호
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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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    • 제28권7호
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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.

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

  • 권중호;변명우;조한옥;최종욱
    • 한국식품과학회지
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    • 제26권2호
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    • pp.167-171
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    • 1994
  • 편의식품 제조용으로 사용되는 시금치 분말의 미생물학적 품질개선을 목적으로 ethylene oxide와 감마선 조사의 살균효과 비교와 품질 안정성에 미치는 영향을 조사하였다. 시금치 분말시료의 미생물 혼입도는 $10^{2}{\sim}10^{4}\;cells/g$ 수준으로 내열성포자균, 내산성세균, 곰팡이, 대장균 등이 확인되었다. 상법의 EO 훈증법은 오염미생물의 살균에 불충분하였다. 7 kGy 이하의 감마선은 검사된 미생물을 모두 사멸시켰고 호기성 전세균에 대한 방사선 감수성$(D_{10})$은 2.93kGy로 나타났다. 시금치 분말의 ascorbic acid 및 환원당 함량은 EO 처리에 의해 유의적으로 감소되었으나 10 kGy 이하의 감마선 조사에 대하여 비교적 안정하였고, 살균선량으로 조사된 분말의 색소특성은 관능적 품질에 영향을 미치지 않았다.

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

  • 차환수;정명수
    • 한국식품저장유통학회지
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    • 제9권2호
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    • pp.148-153
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    • 2002
  • 개화 후 71일 만에 수확된 청매실을 20, 30, 40$\mu\textrm{m}$ 두께의 LDPE 필름 포장재에 각각 넣고 상온($25^{\circ}C$) 및 저온($0^{\circ}C$ 와 1$0^{\circ}C$)에 저장하면서 저장 중 일정 시간 간격으로 pH, 산도, 가용성고형분과 클로로필의 함량, 경도, 색상 등의 변화를 측정하여 포장하지 않은 채 저장한 시료에 대한 변화와 비교하였다. 포장재에 넣고 저장한 시료는 포장재의 두께에 관계없이 무포장구에 비해 외관적으로 변화가 훨씬 적음을 확인하였고, 화학적 성질 변화를 억제하는데도 효과가 있음을 알 수 있었다. 특히, 결과를 종합적으로 비교해 보았을때 30$\mu\textrm{m}$ 두께의 LDPE 필름 포장재에 저장하였을 때가 다른 필름 두께의 포장구에 비해 모든 측정 항목에서 변화를 최소화할 수 있는 조건임을 알 수 있었고, 이 사실은 LDPE 30 포장구가 외부차단 효과와 적절한 호흡 특성 유지 효과를 동시에 기대할 수 있는 조건임을 말해 준다.

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

  • 김혜영;김현정
    • 한국식품조리과학회지
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    • 제24권2호
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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.