Effects of repeated freezing and thawing on myofibrillar protein and quality characteristics of marinated Enshi black pork

2022 ◽  
pp. 131994
Author(s):  
Rui Li ◽  
Mengyan Guo ◽  
E Liao ◽  
Qi Wang ◽  
Lijuan Peng ◽  
...  
Keyword(s):  
Quality Characteristics ◽  
Myofibrillar Protein ◽  
Freezing And Thawing ◽  
Repeated Freezing

THE EFFECT OF FREEZING AND THAWING ON THE QUALITY OF CANNED HERRING

1943 ◽  
Vol 21d (1) ◽  
pp. 8-17 ◽  
Author(s):  
F. Charnley ◽  
O. C. Young
Keyword(s):  
Quality Characteristics ◽  
Freezing And Thawing ◽  
Repeated Freezing

The effect of freezing and thawing on the quality of canned herring is investigated by comparing averages of the quality characteristics: firmness, volume of free aqueous liquid, and volume of free oil of treated samples with those of untreated samples. Repeated freezing and thawing definitely impairs the quality of canned herring by causing absorption of an appreciable proportion of the free aqueous liquid and free oil into the interior of the sample and seriously diminishing the firmness of the cooked tissue.

scholarly journals Macro- and microelements in serum and seminal plasma as biomarkers for bull sperm cryotolerance

2021 ◽  
Vol 63 (1) ◽  
Author(s):  
Maja Zakošek Pipan ◽  
Petra Zrimšek ◽  
Breda Jakovac Strajn ◽  
Katarina Pavšič Vrtač ◽  
Tanja Knific ◽  
...  
Keyword(s):  
Seminal Plasma ◽  
Semen Quality ◽  
Sperm Quality ◽  
Membrane Integrity ◽  
Quality Characteristics ◽  
Freezing And Thawing ◽  
Additional Tool ◽  
Bull Semen ◽  
Bull Sperm ◽  
Fresh Semen

ABSTRACT Background Wide variation in fertility rates is observed when using frozen bull semen, even when the bulls have met quality standards for semen production. Therefore, a simple and reliable test to assess the freezing potential of bull semen based on the analysis of fresh semen or blood would be of great value. Attention is now turning to assessment of seminal plasma components such as proteins and elements. In the present study, the concentrations of macro- and microelements in fresh bull semen plasma and in serum and their correlation with quality characteristics of fresh semen and with semen quality after freezing and thawing were determined. Ejaculates were collected from 30 mature bulls, and semen volume, concentration, sperm motility, morphology, tail membrane integrity, plasma membrane permeability and DNA fragmentation were determined on the day of collection and after freezing and thawing. The concentrations of macroelements (Na, Mg, K and Ca) and microelements (Cu, Fe, Zn and Se) were determined in the seminal plasma and serum. The semen samples were classified into satisfactory and unsatisfactory groups according to the fresh semen quality. Results Zinc and Se levels measured in serum were associated with almost all fresh and frozen-thawed semen quality characteristics, while Fe levels were associated only with acrosomal defects in fresh semen. Zinc and Fe levels in fresh seminal plasma were associated with various quality characteristics of fresh and frozen-thawed semen, while Se level in fresh seminal plasma was not associated with any of the semen quality characteristics. Conclusions Microelements were shown to be useful as biomarkers involved in the analysis of bull sperm quality and could be used as an additional tool to predict bull semen quality after freezing and thawing. Our results confirm that the analysis of Zn and Se levels in serum and Zn, Cu and Fe levels in fresh seminal plasma can provide information to discriminate between bull semen samples with spermatozoa with high or low cryotolerance.

scholarly journals ISOZYMES OF ACID PHOSPHATASE IN NORMAL AND CALMETTE-GUÉRIN BACILLUS-INDUCED RABBIT ALVEOLAR MACROPHAGES

1968 ◽  
Vol 128 (5) ◽  
pp. 1031-1048 ◽  
Author(s):  
S. G. Axline
Keyword(s):  
Acid Phosphatase ◽  
Phosphatase Activity ◽  
Alveolar Macrophages ◽  
Acid Phosphatase Activity ◽  
Enzyme Inhibitors ◽  
Freezing And Thawing ◽  
Ph Optimum ◽  
Lysosomal Fraction ◽  
Repeated Freezing ◽  
Major Acid

The acid phosphatase activity of normal alveolar and BCG-induced alveolar macrophages has been examined. Five electrophoretically distinct forms of acid phosphatase have been identified in both normal and BCG-induced macrophages. The acid phosphatases can be divided into two major categories. One category, containing four distinct forms, is readily solubilized after repeated freezing and thawing or mechanical disruption The second category, containing one form, is firmly bound to the lysosomal membrane and can be solubilized by treatment of the lysosomal fraction with Triton X-100. The Triton-extractable acid phosphatase and the predominant aqueous soluble acid phosphatase have been shown to differ in the degree of membrane binding, in solubility, in net charge, and in molecular weight. The two pre-dominant phosphatases possess identical pH optimum and do not differ in response to enzyme inhibitors. BCG stimulation has been shown to result in a nearly twofold increase in acid phosphatase activity. A nearly proportionate increase in the major acid phosphatase forms has been observed.

scholarly journals STUDIES ON OXIDATION AND REDUCTION BY PNEUMOCOCCUS

1924 ◽  
Vol 39 (3) ◽  
pp. 357-366 ◽  
Author(s):  
Oswald T. Avery ◽  
James M. Neill
Keyword(s):  
Yeast Extract ◽  
Room Temperature ◽  
Prolonged Exposure ◽  
Freezing And Thawing ◽  
Peroxide Formation ◽  
Cell Extracts ◽  
Repeated Freezing ◽  
Phosphate Solutions ◽  
Animal Tests

In the present paper methods have been described for the preparation of sterile extracts of pneumococci. These extracts may be obtained by dissolving the bacteria in broth cultures by means of bile, or by extraction of the cellular substances by repeated freezing and thawing of broth or saline suspensions of unwashed cells. Under special precautions these extracts may be passed through Berkefeld filters without loss of potency. In this procedure, as in all other manipulations incident to their preparation, the extracts should be protected as far as possible from contact with air. All extracts were proved sterile by cultural and animal tests. Sterile extracts of unwashed pneumococcus cells promptly form peroxide on exposure to air. Peroxide formation is almost as active in extracts aerated at 2°C. as in those exposed to the air at room temperature. Detectable amounts of peroxide may be produced by these cell extracts within the reaction range of pH 5 to 9, the optimal zone lying at reactions less acid than pH 6. The peroxide-forming activity of the extracts is gradually diminished by prolonged exposure to 55°C., and is completely destroyed by heating at 65°C. for 5 minutes. Cell extracts of pneumococci which have been thoroughly washed prior to extraction in salt or phosphate solutions exhibit no peroxide-forming activity. These extracts of washed cells may be activated by the addition of the cell washings, yeast extract, or muscle infusion.

Effects of perturbations and stimulants on red raspberry (Rubus idaeus L.) seed germination

1997 ◽  
Vol 73 (4) ◽  
pp. 453-457 ◽  
Author(s):  
R. A. Lautenschlager
Keyword(s):  
Seed Coat ◽  
Temperature Fluctuations ◽  
Rubus Idaeus ◽  
Red Raspberry ◽  
Freezing And Thawing ◽  
Short Term ◽  
Repeated Freezing ◽  
Key Words Animal ◽  
Concentrated Sulfuric Acid ◽  
Seed Coats

Red raspberry (Rubus idaeus L.) seeds germinate only after seed coats are degraded. In nature this happens slowly. Seeds from recently collected fruit (fresh to four years old) germinated only after scarification of the seed coat by 20-minute soaking in concentrated sulfuric acid. Germination was not enhanced by: (1) short-term intermittent soaking, up to 81 hours, in dilute (0.01 normal) hydrochloric acid; (2) passage through the digestive tracts of bears, coyotes, or birds; (3) physical perturbations such as nicking, mechanical scarification, repeated freezing and thawing and/or four years of exposure in the field; (4) exposure to light; (5) increased temperatures or temperature fluctuations; or (6) addition of nitrogen (ammonium nitrate, urea). Key words: animal passage, germination, nitrogen, red raspberry, Rubus idaeus L., seed coat, seed weight, scarification, stratification

Simple method for preparing a concentration gradient of serum components by freezing and thawing

1991 ◽  
Vol 37 (7) ◽  
pp. 1225-1229 ◽  
Author(s):  
Tetsuo Hirano ◽  
Toshiaki Yoneyama ◽  
Hiroko Matsuzaki ◽  
Takainitsu Sekine
Keyword(s):  
Concentration Gradient ◽  
Clinical Laboratory ◽  
Freezing Temperature ◽  
Test Results ◽  
Freezing And Thawing ◽  
Serum Samples ◽  
Simple Method ◽  
Gradient Formation ◽  
Repeated Freezing ◽  
Serum Components

Abstract We created a simple method for obtaining a series of successively more-concentrated samples from a serum without changing the ratio of its components. We froze a pooled serum and then allowed it to thaw undisturbed. The serum components formed a gradient of increasing concentration from the top of the sample to the bottom. We found that (a) in test results, each fraction of serum in the gradient showed almost the same relative concentrations of components (i.e., inorganic and organic compounds, proteins, metals, and hormones), irrespective of atomic or molecular mass; (b) the concentration gradient depended on the thawing temperature but not on the freezing temperature; (c) when we thawed the frozen sample with centrifugation, the slope of the concentration gradient increased with increasing centrifugal force; (d) when the thawed sample was fractionated into 10 fractions from the top to the bottom, the original serum concentration was always maintained between the sixth and seventh fractions from the top; and (e) the concentration gradient became steeper with repeated freezing and thawing. By using this method, one can easily prepare serum samples at gradients of concentration useful in the clinical laboratory, although the mechanism of gradient formation is still unclear.

FREEZE-THAW EFFECTS ON GRANULAR STRUCTURE REORGANIZATION FOR SOIL MATERIALS OF VARYING TEXTURE AND MOISTURE CONTENT

1988 ◽  
Vol 68 (3) ◽  
pp. 485-494 ◽  
Author(s):  
S. PAWLUK
Keyword(s):  
Moisture Content ◽  
Lacustrine Sediments ◽  
Field Capacity ◽  
Granular Structure ◽  
Glacial Till ◽  
Microstructural Development ◽  
Clay Loam ◽  
Freezing And Thawing ◽  
Freeze Thaw ◽  
Repeated Freezing

Repeated freezing and thawing of glacial till cores of clay loam texture results in the formation of granic and metafragmic microfabrics. These units of fabric are best developed near the surface of cores kept at moisture levels between field capacity and saturation. Well-sorted lacustrine sediments with fewer voids tend to form banded fabrics. Many of the morphological features such as vesicles, metavughs and desiccation cracks commonly attributed to freeze-thaw processes are evident in all materials tested. Discrete units of fabric observed in this study are very similar to units of fabric observed in the Ah horizons of Black Chernozemic and Cryosolic soils. Results of this investigation strongly support earlier research which suggests that frost processes are major contributors to their microstructural development. Key words: Granic, freeze-thaw, microfabrics

scholarly journals Association of newly synthesized islet prohormones with intracellular membranes.

1984 ◽  
Vol 99 (2) ◽  
pp. 418-424 ◽  
Author(s):  
B D Noe ◽  
M N Moran
Keyword(s):  
Secretory Granules ◽  
Gradient Centrifugation ◽  
Gel Filtration ◽  
Proteolytic Processing ◽  
Membrane Association ◽  
Freezing And Thawing ◽  
Ph Optimum ◽  
Intracellular Membranes ◽  
Membrane Lysis ◽  
Repeated Freezing

Results from recent studies have indicated that pancreatic islet prohormone converting enzymes are membrane-associated in islet microsomes and secretory granules. This observation, along with the demonstration that proglucagon is topologically segregated to the periphery within alpha cell secretory granules in several species, led us to investigate the possibility that newly synthesized islet prohormones might be associated with intracellular membranes. Anglerfish islets were incubated with [3H]tryptophan and [14C]isoleucine for 3 h, then fractionated by differential and density gradient centrifugation. Microsome (M) and secretory granule (SG) fractions were halved, sedimented, and resuspended in the presence or absence of dissociative reagents. After membrane lysis by repeated freezing and thawing, the membranous and soluble components were separated by centrifugation. Extracts of supernatants and pellets were chromatographed by gel filtration; fractions were collected and counted. A high proportion (77-79%) of the newly synthesized proinsulin and insulin was associated with both M and SG membranes. Most of the newly synthesized proglucagons and prosomatostatins (12,000-mol-wt precursors) were also membrane-associated (86-88%) in M and SG. In contrast, glucagon- and somatostatin-related peptides exhibited much less membrane-association in SG (24-31%). Bacitracin, bovine serum albumin EDTA, RNAse, alpha-methylmannoside, N-acetylglucosamine, and dithiodipyridine had no effect on prohormone association with membranes. However, high salt (1 M KCl) significantly reduced membrane-association of prohormones. Binding of labeled prohormones to SG membranes from unlabeled tissue increased with incubation time and was inhibited by unlabeled prohormones. The pH optimum for prohormone binding to both M and SG membranes was 5.2. It is suggested that association of newly synthesized prohormones with intracellular membranes could be related to the facilitation of proteolytic processing of prohormones and/or transport from their site of synthesis to the secretory granules.

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