Differential roles of ice crystal, endogenous proteolytic activities and oxidation in softening of obscure pufferfish (Takifugu obscurus) fillets during frozen storage

2019 ◽  
Vol 278 ◽  
pp. 452-459 ◽  
Author(s):  
Fang Yang ◽  
Diantao Jing ◽  
Dawei Yu ◽  
Wenshui Xia ◽  
Qixing Jiang ◽  
...  
Keyword(s):  
Frozen Storage ◽  
Ice Crystal ◽  
Takifugu Obscurus ◽  
Proteolytic Activities

scholarly journals Effects of Different Freezing Methods on Water Distribution, Microstructure and Protein Properties of Cuttlefish during the Frozen Storage

2021 ◽  
Vol 11 (15) ◽  
pp. 6866
Author(s):  
Ying Lv ◽  
Yuanming Chu ◽  
Pengcheng Zhou ◽  
Jun Mei ◽  
Jing Xie
Keyword(s):  
Liquid Nitrogen ◽  
Water Retention ◽  
Loss Rate ◽  
Saline Solution ◽  
Frozen Storage ◽  
Protein Secondary Structure ◽  
Freezing Process ◽  
Ice Crystal ◽  
Air Blast ◽  
Freezing Method

To study the effect of different freezing methods on the quality changes of cuttlefish during the frozen storage of cuttlefish, fresh cuttlefish was treated with six freezing methods (refrigerator direct-freezing, saline solution impregnation freezing, flat freezing, tunnel type continuous freezing, air-blast freezing and liquid nitrogen freezing) and then stored at −18 °C for 90 days. The time to pass the maximum ice crystal generation zone for the above six freezing methods in this experiment was 165.5, 67.5, 34.5, 21.8, 20.4 and 1.5 min, respectively. In this study, water retention (thawing loss rate, centrifugal loss rate, and cooking loss), pH, malondialdehyde content, TVB-N value, and sulfhydryl content were measured to evaluate the quality after thawing. Protein secondary structure was measured by attenuated total reflection infrared spectroscopy (ATR-FTIR), water migration was determined by low-field NMR, and muscle microstructure was observed by scanning electron microscopy. The results showed that among the six freezing methods, liquid nitrogen freezing took the shortest time to pass through the maximum ice crystal generation zone. And it had the highest water retention, the lowest TVB-N content, the highest sulfhydryl content and the least irregular curling of protein secondary structure after 90 days of frozen storage. However, liquid nitrogen freezing can cause cracks and breakage in cuttlefish due to cryogenic fracture caused by ultra-low temperature, which affects its sensory evaluation. Although the freezing speed of flat freezing is faster than refrigerator direct-freezing and saline solution impregnation freezing, the muscle is extruded and deformed during the freezing process, and the damage is more serious, and the frozen storage quality is the worst. The comprehensive analysis results showed that the freezing speed of air- blast freezing was faster and the quality of cuttlefish in the freezing process was better, which was the more recommended freezing method, and this study provided some theoretical basis for the selection of freezing method in the actual production of cuttlefish.

Effect of different extent of protein oxidation on the frozen storage stability of muscle protein in obscure pufferfish (Takifugu obscurus)

LWT ◽  
2021 ◽  
Vol 137 ◽  
pp. 110416
Author(s):  
Yao Zheng ◽  
Fen Zhou ◽  
Long Zhang ◽  
Hongli Wang ◽  
Xi-chang Wang
Keyword(s):  
Protein Oxidation ◽  
Storage Stability ◽  
Muscle Protein ◽  
Frozen Storage ◽  
Takifugu Obscurus

Understanding the influence of carrageenan oligosaccharides and xylooligosaccharides on ice-crystal growth in peeled shrimp (Litopenaeus vannamei) during frozen storage

2018 ◽  
Vol 9 (8) ◽  
pp. 4394-4403 ◽  
Author(s):  
Bin Zhang ◽  
Xiao-li Zhang ◽  
Chun-lei Shen ◽  
Shang-gui Deng
Keyword(s):  
Crystal Growth ◽  
Litopenaeus Vannamei ◽  
Protein Denaturation ◽  
Frozen Storage ◽  
Ice Crystal

Cryoprotective saccharides are widely accepted antifreeze additives that reduce thawing loss, maintain texture, and retard protein denaturation in frozen seafood.

scholarly journals Exploring the Effect of Dehydration on Water Migrating Property and Protein Changes of Large Yellow Croaker (Pseudosciaena crocea) during Frozen Storage

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 784
Author(s):  
Mingtang Tan ◽  
Jing Xie
Keyword(s):  
Frozen Storage ◽  
Surface Hydrophobicity ◽  
Ice Crystals ◽  
Slow Freezing ◽  
Large Yellow Croaker ◽  
Ice Crystal ◽  
Tertiary Structures ◽  
Ice Crystal Size ◽  
Freeze Dryer ◽  
Ice Sublimation

This study aimed to explore the effect of dehydration on the water migrating property and protein changes of large yellow croaker during frozen storage. A freeze-dryer was used to accelerate experiments, which was isolated from oxygen and excluded the effects of protein oxidation. After dehydration time (3, 9, 18, and 30 h) for both fast- and slow-freezing samples, the results showed that the ice sublimation of samples containing small ice crystals was faster than that of samples containing large ice crystals in the early stages of dehydration, but in the latest stage, there was an opposite trend. The results indicated that dehydration reduced the water freedom degrees and water–protein interaction. At the same time, dehydration had a significant effect on protein secondary and tertiary structures. The significant increase in surface hydrophobicity and particle size indicated that dehydration exacerbated myofibrillar protein aggregation. The ΔH1 values (from 1.275 to 0.834 J/g for slow-freezing group and from 1.129 to 0.855 J/g for fast-freezing group) decreased gradually as the dehydration time extended, indicating the decrease in protein thermal stability. Additionally, significant protein degradation occurred when the water content of the sample decreased to a certain level. This study showed that ice crystal size had an important effect on the rate of ice sublimation, and the occurrence of dehydration during frozen storage accelerated the water loss and the decrease in protein stability.

High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

1991 ◽  
Vol 49 ◽  
pp. 64-65
Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Low Voltage ◽  
Culture Media ◽  
Cell Structure ◽  
Freeze Substitution ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Culture Media ◽  
Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

Cryosectioning plant roots prepared by high-pressure freezing

1987 ◽  
Vol 45 ◽  
pp. 662-663
Author(s):  
R.E. Crang ◽  
M. Mueller ◽  
K. Zierold
Keyword(s):  
High Pressure ◽  
Cell Walls ◽  
Plant Tissues ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Vitreous State ◽  
Radial Depth ◽  
Irregular Topography ◽  
Considerable Depth ◽  
Conventional Freezing

Obtaining frozen-hydrated sections of plant tissues for electron microscopy and microanalysis has been considered difficult, if not impossible, due primarily to the considerable depth of effective freezing in the tissues which would be required. The greatest depth of vitreous freezing is generally considered to be only 15-20 μm in animal specimens. Plant cells are often much larger in diameter and, if several cells are required to be intact, ice crystal damage can be expected to be so severe as to prevent successful cryoultramicrotomy. The very nature of cell walls, intercellular air spaces, irregular topography, and large vacuoles often make it impractical to use immersion, metal-mirror, or jet freezing techniques for botanical material.However, it has been proposed that high-pressure freezing (HPF) may offer an alternative to the more conventional freezing techniques, inasmuch as non-cryoprotected specimens may be frozen in a vitreous, or near-vitreous state, to a radial depth of at least 0.5 mm.

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