• Title/Summary/Keyword: Freeze-thawing

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Quality Characteristics of Mixed Polysaccharide Gels with Various Kiwifruit Contents by Freeze-Thawing (키위 첨가 다당류 흔합겔의 냉동ㆍ해동에 따른 품질 특성)

  • 윤혜신;오명숙
    • Korean journal of food and cookery science
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    • v.19 no.6
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    • pp.758-764
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    • 2003
  • This study was performed to determine the quality characteristics of mixed polysaccharide gels made from kcarrageenan and locust bean gum with various kiwifruit content after freeze-thawing. The syneresis, rupture properties, TPA properties and sensory properties of the mixed polysaccharide gels with various kiwifruit contents after freeze-thawing were measured. The syneresis of the gel with various kiwifruit contents by freeze-thawing was not significantly different, whereas repeating freeze-thawing resulted in remarkable increase in the syneresis of the mixed polysaccharide gels with 5%, 20% and 40% kiwifruit. In terms of the rupture properties, the rupture stress, rupture energy and rupture strain decreased with increasing kiwifruit content after freeze-thawing. In terms of the TPA properties, the adhesiveness, hardness and chewiness increased and the cohesiveness decreased with increasing kiwifruit content after freeze-thawing. The rupture properties, springiness and cohesiveness of the gel by freeze-thawing were lower than those of the gel stored in the refrigerator. In contrast, the gumminess, hardness and chewiness of the gel after freeze-thawing were higher than those of the gel stored in the refrigerator. The results showed that the gel became crumbly and tough as a result of freeze-thawing. In the sensory evaluation, He overall acceptability of the gel after freeze-thawing was highest at the 30% kiwifruit content, and differences in the sensory properties between the gel after freeze-thawing and that stored in the refrigerator were small. Therefore, mixed polysaccharide gels with kiwifruit after freeze-thawing could be useful despite the small decrease in quality.

An Evaluation of Resistances in Porous Asphalt Concrete Mixtures due to Repeated Cyclic Freeze-Thawing (배수성 아스팔트콘크리트 혼합물의 반복 동결융해 저항성 평가)

  • Jo, Shin Haeng;Kim, Nakseok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.1D
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    • pp.33-39
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    • 2012
  • More and more pavements are suffering from damage these days due to the below-zero winter temperatures and frequent snowfalls. From this research, the freeze-thawing mechanisms of pavements will be observed, and the freeze-thawing resistance of porous asphalt concrete mixture is to be evaluated according to various assessment methods. The investigation was conducted through applying rigid and flexible pavements to freeze-thawing resistance experiments, which include various experiments such as deformation rate measurements, Lottman tests, repeated cyclic freeze-thawing experiments, stripping resistance tests and so on. Test results revealed that the porous asphalt concrete had less deformations according to temperatures compared to dense-graded asphalt concrete due to the 20% void gap. In addition, according to the freeze-thawing repetition experiments which are effected by moisture, the porous asphalt concrete mixture showed superior resistance to repeated cyclic freeze-thawing compared to other asphalt concrete mixtures due to the drainage and the voids within the specimen.

Flexural Behavior of Reinforced Concrete Beams Exposed to Freeze-Thawing Environments (동결융해 환경에 노출된 철근콘크리트 보의 휨 거동특성)

  • Jang, Gwang-Soo;Yun, Hyun-Do;Kim, Sun-Woo;Park, Wan-Shin;Choi, Ki-Bong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.6 s.58
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    • pp.126-134
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    • 2009
  • Generally, reinforced concrete structures exposed to the outside temperature are affected by freezing and thawing process during winter and early spring. These freeze-thawing process can lead to the reduction in durability of concrete as cracking or surface spalling. This paper is to study the flexural behavior of RC beams exposed to freeze-thawing environments. To compare the difference in flexural behavior of RC Beams, limited tests were conducted under different types of Longitudinal steel ratio and freeze-thawing cycles. For this purpose, fourteen small-scale RC beams ($100mm{\times} 100mm {\times}600mm$) were strengthened in monotonic and cyclic loadings, subjected to up to 150, 300 cycles freeze-thawing from $-18{\sim}4^{\circ}C$. It is thought that experimental results will be used as basic data to evaluate flexural behavior of RC beams exposed to freeze-thawing.

Extraction Characteristics on Soaked Liquor of Omija (Schisandra chinensis) by Freeze-thawing Process (냉해동 처리에 따른 오미자 담금주의 추출 특성)

  • Lee, Eun Suk;Jee, Yun-jeong;Lee, Seung Eun;Kim, Hyung Don;Choi, Jehun;Kang, Min Hye;Kim, Geum Soog;Choi, Su Ji;Jang, Gwi Yeong
    • The Korean Journal of Food And Nutrition
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    • v.34 no.3
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    • pp.263-271
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    • 2021
  • Fresh Omija (Schisandra chinensis) has good marketability, but its quality is difficult to maintain during storage and distribution. Freezing and freeze-thawing treatments can be utilized for the quality maintenance and processing of cold press juice. In this study, the color, antioxidant properties, and the major components of soaked liquor from Omija with freeze-thawing treatment were analyzed during the extraction periods. Each of the frozen and freeze-thawed Omija samples was soaked in 35% ethanol, extracted for 15 days, and used for analysis. The frozen and freeze-thawed samples showed a tendency toward better color and higher antioxidant activity and major component levels than the controls, and freeze-thawing was the best. The results of this study showed that freeze-thawing treatment improved the color, antioxidant properties, and level of the major components of Omija soaked liquor, and freeze storage is suitable for making soaked liquor.

Degradation of Phospholipids of Yeast after Freeze-Thawing

  • Hahn, Young-Sook
    • Preventive Nutrition and Food Science
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    • v.1 no.2
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    • pp.252-255
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    • 1996
  • As an index of freeze-injury of yeast, the leakage of intracellular substances from yeast cells after freeze-thawing was investigated. It was found that much more ultraviolet-absorbing substances leaked out from non-freeze tolerant yeast (NETY) than from freeze-tolerant yeast. Furthermore, the rate of leakage of cellular substances form NFTY during incubation exceeded that of FTY, indicating that NFTY is more susceptible to freeze-injury than FTY during frozen-storage. An apparent degradation of phospholipid was observed during incubation of perfermented frozen-cells of NFTY, while little change of phospholipid occurred in FTY, These results suggested that the difference in the sensitivity of yeast might be due to the strength of cell membrane in terms of the degradation of phospholipid by enzymes, phospholipases, attached to cell membranes.

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Assessing Individual Muscle Characteristics to Enhance Frozen-Thawed Meat Quality

  • Choeun Im;Sumin Song;Huilin Cheng;Junyoung Park;Gap-Don Kim
    • Food Science of Animal Resources
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    • v.44 no.4
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    • pp.758-778
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    • 2024
  • This study assessed previous research aimed at mitigating the adverse effects of freeze-thawing on meat quality. Specifically, it focuses on assessing the physicochemical alterations in meat resulting from freezing, freeze-thawing, or technologies to minimize these alterations. Recent studies have focused on conventional freeze-thaw technology applicable across various livestock species and muscle types. However, recent research has indicated the necessity for developing freeze-thaw technology considering the unique characteristics of individual muscles. In this review, we summarize previous studies that have compared alterations in the physicochemical properties of primary muscles owing to freezing or freeze-thawing. Despite the introduction of various technologies to significantly reduce the adverse effects on meat quality resulting from freeze-thawing, it is essential to consider the unique characteristics (proximate composition, pH, and muscle fiber characteristics) of individual muscles or cuts to develop enhanced the freeze-thaw processing technology.

Effect of Repeated Freeze-Thaw Cycles on Beef Quality and Safety

  • Rahman, Mohammad Hafizur;Hossain, Mohammad Mujaffar;Rahman, Syed Mohammad Ehsanur;Hashem, Mohammad Abul;Oh, Deog-Hwan
    • Food Science of Animal Resources
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    • v.34 no.4
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    • pp.482-495
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    • 2014
  • The objectives of this study were to know the effect of repeated freeze-thaw cycles of beef on the sensory, physicochemical quality and microbiological assessment. The effects of three successive freeze-thaw cycles on beef forelimb were investigated comparing with unfrozen fresh beef for 75 d by keeping at $-20{\pm}1^{\circ}C$. The freeze-thaw cycles were subjected to three thawing methods and carried out to know the best one. As the number of freeze-thaw cycles increased color and odor declined significantly before cook within the cycles and tenderness, overall acceptability also declined among the cycles after cook by thawing methods. The thawing loss increased and dripping loss decreased significantly (p<0.05). Water holding capacity (WHC) increased (p<0.05) until two cycles and then decreased. Cooking loss increased in cycle 1 and 3, but decreased in cycle 2. pH decreased significantly (p<0.05) among the cycles. Moreover, drip loss, cooking loss and WHC were affected (p<0.05) by thawing methods within the cycles. 2-Thiobarbituric acid (TBARS) value increased (p<0.05) gradually within the cycles and among the cycles by thawing methods. Total viable bacteria, total coliform and total yeast-mould count decreased significantly (p<0.05) within and among the cycles in comparison to the initial count in repeated freeze-thaw cycles. As a result, repeated freeze-thaw cycles affected the sensory, physicochemical and microbiological quality of beef, causing the deterioration of beef quality, but improved the microbiological quality. Although repeated freeze-thaw cycles did not affect much on beef quality and safety but it may be concluded that repeated freeze and thaw should be minimized in terms of beef color for commercial value and WHC and tenderness/juiciness for eating quality.

Influence of freeze-thawed cycles on pork quality

  • Tippala, Tiprawee;Koomkrong, Nunyarat;Kayan, Autchara
    • Animal Bioscience
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    • v.34 no.8
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    • pp.1375-1381
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    • 2021
  • Objective: This study was conducted to determine the effect of freeze-thawed cycles (Fresh meat, F-T 1 cycle and F-T 2 cycles) on the quality characteristics of porcine longissimus dorsi muscle. Methods: A total of 20 three-crossbred pigs (Duroc×[Large White×Landrace]) were randomly obtained from a commercial slaughterhouse in Thailand. Muscle samples were immediately taken from 10 to 11th of the longissimus dorsi for histochemical analysis. The muscles were cut into 2.54 cm-thick chops. A minimum of 20 chops were used for each treatment (fresh meat, freeze-thawed 1 and 2 cycles). Individually chops were packaged in polyethylene bags and frozen at -20℃ for 6 months followed by thawing in refrigerator at 4℃ for 24 h (the 1st freeze-thawed cycle). The freeze-thawed procedure was repeated for two cycles (the 2nd freeze-thawed cycle). Thawing loss, shear force value, citrate synthase activity and muscle fiber characteristics were determined on the muscles. Results: Results showed that increasing of freeze-thawed cycle increased the thawing loss (p<0.01) and citrate synthase activity (p<0.001). Shear force value of fresh meat was higher than freeze-thawed 1 and 2 cycles (F-T 1 cycle and F-T 2 cycles). Freeze-thawed cycles affected muscle characteristics. Muscle fiber area and muscle fiber diameter decreased with an increasing number of freeze-thawed cycles (p<0.001), while the thickness of endomysium and perimysium were increased (p<0.001). Conclusion: Repeated freeze-thawed cycles degraded muscle fiber structure and deteriorated pork quality.

Structural Performance of Reinforced Concrete Beams Exposed to Freeze-Thawing Environment After Strengthening in Shear with Carbon Fiber-Reinforced Polymer(CFRP) (탄소섬유 폴리머로 전단보강 후 동결융해 환경에 노출된 철근콘크리트 보의 구조성능)

  • Song, Seon-Hwa;Kim, Sun-Woo;Park, Wan-Shin;Choi, Ki-Bong;Yun, Hyun-Do
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.13 no.6 s.58
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    • pp.115-125
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    • 2009
  • In these days, carbon fiber-reinforced polymers (CFRP) have been widely used for retrofitting and/or strengthening structural elements. However, there are not enough test data to predict the long-term performance of the retrofitted structures exposed to freeze-thawing cycles. This paper presents the results of experimental program undertaken to investigate the effects of freeze-thawing cycling (from-18 to $4^{\circ}C) on the behavior and failure characteristics of reinforced concrete (RC) beams strengthened in shear with CFRP sheet and plate using acoustic emission (AE) technique.

Effect of Emulsified Refine Cooking Oil and Expandable Microsphere on Durability of High-Volume Blast Furnace Slag Concrete (정제유지류 및 팽창성 인공 기포 조합이 고로슬래그 다량치환 콘크리트의 내구성 및 미시적 특성에 미치는 영향)

  • Han, Min-Cheol;Han, Dongyeop;Lee, Myung-Ho
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.2
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    • pp.201-207
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    • 2015
  • In this paper, a series of experiments was conducted to evaluate the resistibility of carbonation and freeze-thawing damage of the high-volume blast furnace slag concrete using expancel, the expandable microsphere, and ERCO, emulsified refine cooking oil. The concrete mixture of 0.45 water-to-binder ratio with 60% of blast furnace slag was evaluated for carbonation, freeze-thawing resistibility, SEM, and porosity. According to the previous research, replacing ERCO contributes on improving carbonation resistibility with capillary pore filling effect by soap foaming reaction of ERCO while significantly decreased freeze-thawing resistibility. To improve this decreased freeze-thawing resistibility, expancel was used, and thus freeze-thawing resistibility was improved as the replacement ratio of expancel was increased. It is considered that the selective volume shrunken effect of expancel due to the external pressure and decreased air void spacing factor due to expancel.