• Title/Summary/Keyword: physicochemical changes

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Effects of Packaging Materials on the Physicochemical Characteristics of Seasoned Anchovies During Storage (포장재가 멸치조미가공품의 저장 중 이화학적 품질 특성에 미치는 영향)

  • Lee, Eui-Seok;Lee, Hyong-Ju;Bae, Jae-Seok;Kim, Yong-Kuk;Lee, Jong-Hyeouk;Hong, Soon-Taek
    • Journal of the East Asian Society of Dietary Life
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    • v.23 no.4
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    • pp.461-469
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    • 2013
  • This research is performed to investigate the changes in the physicochemical properties and microbial growths of seasoned anchovies with various packaging materials (PET/CPP : polyethylene terephthalate/cast polypropylene, PET/EVOH : polyethylene terephthalate/ethylene-vinyl alcohol, PET/AL/LDPE: polyethylene terephthalate/aluminum/low density polyethylene), which are stored at various temperatures (25, 35, $45^{\circ}C$) for 60 days. Generally, it is being observed that changes in physicochemical properties (i.e., moisture content, color, brown intensity, TBA value, TMA, VBN etc) of seasoned anchovies are significant when stored at higher temperatures. Particularly, the packaging materials are found to influence substantially on the physicochemical properties of seasoned anchovies. With packaging materials of high oxygen transmission rates and moisture vapor transmission rates (i.e., PET/CPP), the changes in physicochemical properties of seasoned anchovies are significant, while being low with low oxygen transmission rates and low moisture vapor transmission rates (i.e., PET/EVOH). In addition, results of microbial growths in seasoned anchovies show that significant increases in total aerobic bacteria counts (about 100-fold after 60 day of storage) are observed in samples with packaging materials of high oxygen transmission rates and moisture vapor transmission rates (i.e, PET/CPP), while with only small increases for samples of low oxygen transmission rates and low moisture vapor transmission rates (i.e., PET/EVOH). Based on the changes in the physicochemical properties and results of microbial growths, it is being concluded that PET/EVOH film is suitable for the packaging of seasoned anchovies.

Physicochemical Properties of Soybeans as Influenced by Storage Temperatures (저장온도가 콩의 이화학적 특성에 미치는 영향)

  • 육홍선;설민숙;이현자
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.5
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    • pp.827-832
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    • 1998
  • Soybeans(Hwangkeum Kong) were stored at 5$^{\circ}C$, $25^{\circ}C$ and 35$^{\circ}C$ for 8 months to investigate the changes of the physicochemical properties. Less physicochemical changes were detected in the soybeans stored at 5$^{\circ}C$ than those stored at $25^{\circ}C$ and 35$^{\circ}C$. High temperature and long term storage caused a decrease in the nitrogen solubility index, whereas increases in acid value and organic acid content were detected. As the storage period was extended at high temperatues, the content of unsaturated fatty acids decreased, but the content of saturated fatty acids increased. Decoloration of soybeans was clearly recognized under high temperatures. The water soluble compoents such as total solids, nitrogen and reducing sugar during water-soaking at 2$0^{\circ}C$ for 16hrs were appreciably eluted from the soybeans stored for 8 months at high temperatures. The pH of the water extract slightly shifted to the acidic range.

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Physicochemical Quality of Boiled-Dried Anchovies during Post-Irradiation Period (감마선 조사가 건멸치의 이화학적 품질안정성에 미치는 영향)

  • 권중호;변명우;김영회
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.25 no.3
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    • pp.484-490
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    • 1996
  • Physicochemical changes were determined for the boiled-dried anchovies packaged in a laminated film(nylon 15${\mu}{\textrm}{m}$/polyethylene 100${\mu}{\textrm}{m}$) and stored for one year at ambient and cooling(5~1$0^{\circ}C$) temperatures after gamma irradiation. Lipophilic and hydrophilic browning pigments increased with storage time particularly at ambient temperature, even though initial 5 kGy irradiation did not affect the formation of pigments significantly. This results were confirmed by the instrumental color determinations, Hunter color L, a, b and ΔE. With respect to changes in relative fatty acid compositions, storage period and temperature were more influential factors than gamma irradiation. Irradiation at 5 kGy induced insignificant changes in the total flavor profiles of stored anchovies, which were mainly composed of n-dodecanal(26.7%), n-pentadecane(22.2%), n-octanal(4.9%) and 2-pentylfuran(3.4%).

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Changes in the Physicochemical Properties and Functional Components of Uncooked Foods Treated with Electrolyzed Water

  • Jin, Tie-Van;Oh, Deog-Hwan;Eun, Jong-Bang
    • Food Science and Biotechnology
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    • v.17 no.1
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    • pp.72-79
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    • 2008
  • In this study, changes in the physicochemical properties and functional components of uncooked foods, including carrots, cabbage, shiitake (Lentinus edodes) and white button (Agaricus bisporus) mushrooms, sea mustard, and laver treated with electrolyzed water were investigated. No changes were observed in the primary compositions of any of the materials that were hot air- or freeze-dried after being treated with electrolyzed water. The lightness (L), redness (a), and yellowness (b) values of the carrots, shiitake, and laver were not affected by drying, while changes did occur in the cabbage (L-, a-, and b-values), mushrooms (a-value), and sea mustard (b-value) specimens that were hot air- or freeze-dried following the treatments with electrolyzed water. The dietary fiber contents of all the materials increased when they were hot air-dried. Vitamin C content decreased when the samples were treated with alkalic electrolyzed water. No changes occurred in the lectin, $\beta$-carotene, or total phenolic compound contents after the electrolyzed water treatments, suggesting that electrolyzed water could be used effectively as a pasteurization step for uncooked carrots, cabbage, shiitake and white button mushrooms, sea mustard, and laver.

Physicochemical and Microbiological Changes in Dongchlmi Juice during Fermentaion with the Addition of Panax ginseng C.A. Meyer (인삼을 첨가한 동치미 쥬스 발효중 이화학적 및 미생물의 변화)

  • 권수미;김용진
    • Journal of Ginseng Research
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    • v.20 no.3
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    • pp.299-306
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    • 1996
  • This study was undertaken to examine the effects of fresh ginseng on the physicochemical and microbiological changes in dongchimi juice fermented under various conditions. The pH was somewhat lower in dongchimi juice added with 2.0% and 4.0% of fresh ginseng than that without ginseng, whereas the titratable acidity was higher in dongchimi juice with 2.0% and 4.0% of ginseng addition than the control. The addition of fresh ginseng to dongchimi preparation increased the numbers of total viable bacteria, lactic acid bacteria including Leuconostac mesenterotdes in dongchimi juice during fermentation. The changes in the counts of lactic acid bacteria were similar to those of total viable cells throughout the experiment except the initial stage of fermentation. However, the number of Leucosfastoc mesenternidgs decreased after the palatable stage. Key words : Panax ginseng C.A. Meyer, dongchlmi juice, pH, titratable acidity, microbiological changes.

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Changes in the Physicochemical Properties and Color Values of Salted and Fermented Shrimp (새우젓 발효 중 이화학적 특성 및 색도 변화)

  • Cho, Hee-Sook;Kim, Kyung-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.20 no.1
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    • pp.69-76
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    • 2010
  • This study was performed to examine the effects of salt addition level on changes in the physicochemical properties and color values of salted shrimp during fermentation. Fresh shrimp were salted with different concentrations (8, 18, 28%) of Chunil salt and fermented at $20^{\circ}C$ for 160 days. In the 8% salted shrimp treatment, volatile basic nitrogen (VBN), amino nitrogen (AN), and trimethylamine (TMA) contents rapidly increased during the fermentation period, while in the 18 and 28% salt groups these increases were reduced throughout the 160 days of fermentation. Thiobarbituric acid (TBA) values increased rapidly for 120 days of fermentation and then decreased. The thiobarbituric acid values of the 18, and 28% salted and fermented shrimp groups were lower than the that of the 8% group. In addition, Hunter's color L, a, and b values decreased as the fermentation period increased.

Changes in Physicochemical Properties of Rice Extrudate Due to Added Isolated Soy Protein (분리대두단백 첨가에 의한 쌀 압출성형물의 물리화학적 특성 변화)

  • Lee, Chan
    • The Korean Journal of Food And Nutrition
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    • v.23 no.1
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    • pp.114-117
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    • 2010
  • The effects of isolated soy protein(ISP) content on the physicochemical properties of extrudates from rice flour produced by a single-screw extruder were evaluated. The integrity index(II), nitrogen solubility index(NSI), rehydration ratio(RR), and density were measured as indices of the changes of physicochemical properties of rice extrudates. Increased amounts of ISP resulted in increased II but decreased RR and density. There was no change in the NSI value. It was concluded that the addition of ISP to the raw material could be helpful in texturization of rice extrudate.

Quality Changes During Storage of Cook-chilled Soybean Sprouts

  • Koo, Kyoung-Mo;Kim, Hyoun-Wook;Lee, Dong-Sun;Lyu, Eun-Soon;Paik, Hyun-Dong
    • Food Science and Biotechnology
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    • v.17 no.3
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    • pp.540-546
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    • 2008
  • Sous vide and packaged cook-chilled soybean sprouts were evaluated for physicochemical quality changes and microbial safety during storage for the purposes of shelf-life extension and industrial application. The physicochemical changes assessed were color, texture, and ascorbic acid concentration. The quality of soybean sprouts became worse with increased periods of storage and better in storage temperature of $3^{\circ}C$ more than in $10^{\circ}C$. The concentration of aerobic bacteria decreased from $2.1{\times}10^8$ to $6.0{\times}10^2\;CFU/g$ after pasteurization, but increased during storage. These bacteria are the same shape as anaerobic and hsychrophilic bacteria, but none of these other organisms were detected after heat treatment. The physicochemical qualities of soybean sprouts and microbial safety were better for products stored at $3^{\circ}C$ than at $10^{\circ}C$. In the case of short storage periods, heat treatment at $70^{\circ}C$ for 2 min was most effective for quality and microbial safety.

Physicochemical Properties of Poloxamer-based Gel Containing Capsaicin Analog (캡사이신유도체를 함유하는 폴록사머 겔제제의 물리화학적 특성)

  • Kim, Tae-Wan;Cao, Qing-Ri;Choi, Chun-Young;Lee, Beom-Jin
    • Journal of Pharmaceutical Investigation
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    • v.33 no.1
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    • pp.1-5
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    • 2003
  • Physicochemical changes of poloxamer-based gel containing capsaicin analog (N-[3-(3,4-dimethylphenyl)propyl]-4-(2-aminoethoxy)-3-methoxyphenyl acetamide) such as drug content, viscosity and surface tension were investigated during the storage conditions at three different temperatures (25, 40 and $60^{\circ}C$) over 90 days. No noticeable changes of color were observed when stored at 25 and $40^{\circ}C$. However, the color of white poloxamer gels turned yellow during storage at $60^{\circ}C$. The drug contents were unchanged during storage at $25^{\circ}C$ but had tendency to decrease at $40^{\circ}C$. The drug contents were highly decreased over 40-50% when stored at $60^{\circ}C$. The viscosity of a poloxamer-based gel was unchanged during storage at 25 and $40^{\circ}C$ but greatly increased at $60^{\circ}C$. The surface tension of a poloxamer-based gel was not changed at three different temperatures. The storage conditions of a poloxamer-based gel containing capsaicin analog can be considered for further clinical applications.

Comparative Effect of ${\gamma}$-Irradiation and Ozone Treatment for the Improvement of Hygienic Quality of Dried-Angelica Keiskei Koidz Powder (신선초 분말의 위생화를 위한 오존처리와 감미선 조사와의 비교 효과)

  • 변명우;육홍선;김정옥;김종군;이현자
    • Journal of Food Hygiene and Safety
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    • v.12 no.2
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    • pp.111-116
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    • 1997
  • For the purpose of improving hygienic quality of dried-Angelica Keiskei Koidz powder, the effect of ozone treatment and gamma irradiation on the microbial decontamination and physicochemical properties were investigated. Gamma irradiation at 5 to 7.5 kGy resulted in sterilizing total aerobic bacteria, molds and coliforms below detective levels, while ozone treatment for 8 hours up to 18 ppm did not sufficiently eliminate the total aerobic bacteria of the sample. The physicochemical properties of the sample were not changed by gamma irradiation up to 7.5 kGy, whereas, ozone treatment caused remarkable changes in pH, TBA value, chlorophyll, carotenoid and fatty acid compositions. Therefore, this investigation demonstrated conclusively that gamma irradiation was more effective than ozone treatment for decontaminating and sterilizing the dried-Angelica Keiskei Koidz powder, with minimal effect on the physicochemical properties analyzed.

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