scholarly journals Effect of Protein Denaturation Temperature on Rheological Properties of Baltic Herring (Clupea harengus membras) Muscle Tissue

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 829
Author(s):  
Agnieszka Strzelczak ◽  
Jerzy Balejko ◽  
Mariusz Szymczak ◽  
Agata Witczak
Keyword(s):  
Rheological Properties ◽  
Muscle Tissue ◽  
Protein Denaturation ◽  
Fish Tissue ◽  
Clupea Harengus ◽  
Denaturation Temperature ◽  
Scanning Calorimetry ◽  
Baltic Herring ◽  
Dsc Method ◽  
Degree Of Convergence

The technological properties of raw fish are influenced by the changes in protein structure under heating, which determines the texture and quality of the product. The aim of the study was to examine the protein denaturation temperature and the rheological properties of Baltic herring muscle tissue. The thermal properties were determined by the differential scanning calorimetry (DSC) method and the rheological properties were determined using dynamic oscillatory tests. DSC showed four peaks associated with denaturing transformations of myosin (39.59 °C), sarcoplasm (51.67 °C), connective tissue (63.16 °C), and actin (74.40 °C). Analysis showed that not all transformations occurred according to the same kinetic model. The first two and the last peak are described by 1st order kinetics, while peak 3 is described by 2nd order kinetics. Correlating the changes in fish tissue structure during heating with the rheological characteristics provides more information. The obtained kinetics models correlated very strongly with the results of model testing. Rheological changes of the G’ and G” values had two inflexion points and demonstrate a high degree of convergence with the DSC changes of herring muscle tissue from 20 to 85 °C.

EFFECT OF SODIUM LACTATE ON QUALITY OF LIGHTLY SALTED FISH IN OXYGEN FREE PACKAGING

2017 ◽  
pp. 128-137
Author(s):  
Elena Yuryevna Porotikova ◽  
Boris Lazarevich Nekhamkin ◽  
Mikhail Pavlovich Andreev
Keyword(s):  
Modified Atmosphere Packaging ◽  
Storage Period ◽  
Sodium Lactate ◽  
Vacuum Packaging ◽  
Storage Life ◽  
Clupea Harengus ◽  
Modified Atmosphere ◽  
Salted Fish ◽  
Baltic Herring ◽  
Organoleptic Characteristics

The present article investigates the effect of sodium lactate on microbiological, physico-chemical and sensory characteristics of lightly salted Pacific herring ( Clupea pallasii ) and Baltic herring ( Clupea harengus membras ) during refrigerated storage 5 ± 0.3°C. There have been analyzed different processing methods of lightly salted samples of Pacific and Baltic herring: control (without sodium lactate), and experiment (3% sodium lactate), both in vacuum packaging and modified atmosphere packaging (MAP - 40% CO2/60% N2). For vacuum and MAP there were used bags with low oxygen permeability (3 cm3/m2/day). It was found that 3% sodium lactate keeps firmness of the texture of salted fish muscle and reduces the release of water into the package during storage. Adding 3% sodium lactate reduces the value of the water activity in lightly salted Pacific and Baltic herring by 0.01-0,012 units. The lowest pH (0.02 units) was registered in samples without sodium lactate packed in MAP. Organoleptic signs of spoilage in fish without sodium lactate appeared much earlier, and using 3% sodium lactate both in vacuum and in MAP helped protect and improve organoleptic characteristics of the product during storage. Total biological semination of experimental samples packed in MAP kept at the very low level during the whole storage period, i.e. combined effect of using 3% sodium lactate and MAP inhibited microbial growth. This combination allows to reduce twice the rate of accumulation nitrogen in terminal amino-groups and to increase 1.5-2 times storage life of lightly salted Pacific and Baltic herring, compared to their storage life in vacuum packaging without sodium lactate. The results obtained allow us to recommend using sodium lactate in production of lightly salted fish in oxygen-free packaging, especially in modified atmosphere packaging (40% CO2/60% N2).

Differentiated Scanning Calorimetry of Model Systems with Cocoa Butter

Food Industry ◽  
2020 ◽  
Vol 5 (2) ◽  
pp. 29-36
Author(s):  
Alexander Vereshchagin ◽  
Irina Reznichenko ◽  
Nikolay Bychin
Keyword(s):  
Cocoa Butter ◽  
Palm Olein ◽  
Palm Stearin ◽  
Model Systems ◽  
Scanning Calorimetry ◽  
Glucose Syrup ◽  
Polymorphic Modifications ◽  
Confectionery Products ◽  
System Temperature ◽  
Dsc Method

The article concerns the research specificity of model systems such as cocoa butter – palm olein, cocoa butter – sucrose and cocoa butter – glucose syrup by the differential scanning calorimetry (DSC) method. The researchers run experiments in the temperature range from –100 to –50°C at a heating rate of 10 °C/min. In the cacao butter – palm olein system an eutectic occurs with a palm olein content of 30.0 % indicating the limited solubility of palm olein in cocoa butter. In the cocoa butter – sucrose system, cocoa butter crystallizes as in the α-form (10,0– 30,0; 60.0–90.0 % MK), and as a mixture of α-and β-forms of MK (40.0; 50,0; 70,0 and 80.0 %). Sucrose stabilizes low-temperature polymorphic modifications of cocoa butter. In the cocoa butter – glucose syrup system, temperature of samples melting is 21-22 °C. This composition is promising for use as a filling of confectionery products and glazes production. In this regard, a man can use glucose syrup only in the candy cases production. The role of surfactants used for the formation and stabilization of cocoa butter polymorphs and increasing the thermal stability of the shock-lad without the introduction of palm stearin requires separate consideration.

scholarly journals Enzyme-Assisted Extraction of Fish Oil from Whole Fish and by-Products of Baltic Herring (Clupea harengus membras)

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1811
Author(s):  
Ella Aitta ◽  
Alexis Marsol-Vall ◽  
Annelie Damerau ◽  
Baoru Yang
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fish Oil ◽  
Crude Oil ◽  
Proteolytic Enzymes ◽  
Clupea Harengus ◽  
Omega 3 Fatty Acids ◽  
Omega 3 ◽  
Baltic Herring ◽  
By Products

Baltic herring (Clupea harengus membras) is one of the most abundant commercially caught fish species from the Baltic Sea. Despite the high content of fat and omega-3 fatty acids, the consumption of Baltic herring has decreased dramatically over the last four decades, mostly due to the small sizes and difficulty in processing. At the same time there is an increasing global demand for fish and fish oil rich in omega-3 fatty acids. This study aimed to investigate enzyme-assisted oil extraction as an environmentally friendly process for valorizing the underutilized fish species and by-products to high quality fish oil for human consumption. Three different commercially available proteolytic enzymes (Alcalase®, Neutrase® and Protamex®) and two treatment times (35 and 70 min) were investigated in the extraction of fish oil from whole fish and by-products from filleting of Baltic herring. The oil quality and stability were studied with peroxide- and p-anisidine value analyses, fatty acid analysis with GC-FID, and volatile compounds with HS-SPME-GC-MS. Overall, longer extraction times led to better oil yields but also increased oxidation of the oil. For whole fish, the highest oil yields were from the 70-min extractions with Neutrase and Protamex. Protamex extraction with 35 min resulted in the best fatty acid composition with the highest content of eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) but also increased oxidation compared to treatment with other enzymes. For by-products, the highest oil yield was obtained from the 70-min extraction with Protamex without significant differences in EPA and DHA contents among the oils extracted with different enzymes. Oxidation was lowest in the oil produced with 35-min treatment using Neutrase and Protamex. This study showed the potential of using proteolytic enzymes in the extraction of crude oil from Baltic herring and its by-products. However, further research is needed to optimize enzymatic processing of Baltic herring and its by-products to improve yield and quality of crude oil.

scholarly journals The Influence of the Addition of Nuts on the Thermal and Rheological Properties of Wheat Flour

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3969
Author(s):  
Karolina Pycia ◽  
Lesław Juszczak
Keyword(s):  
Rheological Properties ◽  
Wheat Flour ◽  
Viscoelastic Properties ◽  
Control Sample ◽  
Scanning Calorimetry ◽  
Creep And Recovery ◽  
Research Material ◽  
Pasting Characteristics ◽  
Tan Δ ◽  
Weak Gels

The aim of the study was to assess the influence of replacing wheat flour with hazelnuts or walnuts, in various amounts, on the thermal and rheological properties of the obtained systems. The research material were systems in which wheat flour was replaced with ground hazelnuts (H) or walnuts (W) in the amount of 5%, 10%, and 15%. The parameters of the thermodynamic gelatinization characteristics were determined by the differential scanning calorimetry method. In addition, the pasting characteristics were determined with the use of a viscosity analyzer and the viscoelastic properties were assessed. Sweep frequency and creep and recovery tests were used to assess the viscoelastic properties of the tested gels. It was found that replacing wheat flour with nuts increased the values of gelatinization temperature, gelatinization, and retrogradation enthalpy, and the degree of retrogradation. The highest viscosity was characteristic of the control sample (2039 mPa·s), and the lowest for the paste with 15% addition of walnuts (1120 mPa·s). Replacing the flour with nuts resulted in a very visible reduction in the viscosity of such systems. In addition, gels based on the systems with the addition of H and W were weak gels (tan δ = G″/G′ > 0.1), and the values of G′ and G″ parameters decreased with the increased share of nuts in the systems. Creep and recovery analysis indicated that the systems in which wheat flour was replaced with hazelnuts were less susceptible to deformation compared to the systems with the addition of W.

scholarly journals Characteristics of Reconstituted Collagen Fibers from Chicken Keel Cartilage Depends on Salt Type for Removal of Proteoglycans

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3538
Author(s):  
Anna Pudło ◽  
Szymon Juchniewicz ◽  
Wiesław Kopeć
Keyword(s):  
Electron Microscopy ◽  
Rheological Properties ◽  
Thermal Denaturation ◽  
Surface Structures ◽  
Scanning Calorimetry ◽  
Cartilage Extracellular Matrix ◽  
Oscillatory Rheometry ◽  
Freeze Dried ◽  
Basic Features ◽  
Scanning Electron

The aim of the presented research was to obtain reconstituted atelocollagen fibers after extraction from poultry cartilage using the pepsin-acidic method in order to remove telopeptides from the tropocollagen. Firstly, we examined the extraction of collagen from the cartilage extracellular matrix (ECM) after proteoglycans (PG) had been removed by the action of salts, i.e., NaCl or chaotropic MgCl2. Additionally, the effects of the salt type used for PG and hyaluronic acid removal on the properties of self-assembled fibers in solutions at pH 7.4 and freeze-dried matrices were investigated. The basic features of the obtained fibers were characterized, including thermal properties using scanning calorimetry, rheological properties using dynamic oscillatory rheometry, and the structure by scanning electron microscopy. The fibers obtained after PG removal with both analyzed types of salts had similar thermal denaturation characteristics. However, the fibers after PG removal with NaCl, in contrast to those obtained after MgCl2 treatment, showed different rheological properties during gelatinization and smaller diameter size. Moreover, the degree of fibrillogenesis of collagens after NaCl treatment was complete compared to that with MgCl2, which was only partial (70%). The structures of fibers after lyophilization were fundamentally different. The matrices obtained after NaCl pretreatment form regular scaffolds in contrast to the thin, surface structures of the cartilage matrix after proteoglycans removal using MgCl2.

In-situ observations of Baltic herring (Clupea harengus membras) spawning behaviour in the Ask�-Landsort area, northern Baltic proper

1983 ◽  
Vol 74 (2) ◽  
pp. 105-110 ◽  
Author(s):  
G. Aneer ◽  
G. Florell ◽  
U. Kautsky ◽  
S. Nellbring ◽  
L. Sj�stedt
Keyword(s):  
Clupea Harengus ◽  
Baltic Herring ◽  
Spawning Behaviour ◽  
Baltic Proper ◽  
In Situ Observations
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