Analyzing the Mechanism and Effect of Acid Protease in Wet blue Bating Process for Leather Production

2020 ◽  
Vol 115 (1) ◽  
pp. 10-15
Author(s):  
Hao Li ◽  
Deyi Zhu ◽  
Yanchun Li ◽  
Shan Cao ◽  
Jing Xiao
Keyword(s):  
Molecular Weight ◽  
Raw Materials ◽  
Collagen Fibers ◽  
Acid Protease ◽  
Excellent Performance ◽  
Functional Protein ◽  
Essential Step ◽  
Production Safety ◽  
Chromium Tolerance ◽  
Chromium Resistance

In recent years, in order to reduce the pollution produced in beam-house and tanning sections, more and more tanneries purchase wet blue from other factories in other regions directly used as raw materials for finished leather production thereby those polluted preliminary steps can be eliminated. Therefore, the wet blue bating process is an essential step to minimize the differences of wet blue which are purchased from different regions. In this study, the properties of different acid protease are analyzed for selecting suitable protease used for wet blue bating. The analysis of chromium tolerance of different acid proteases reveals that, L1 and L4 produced from Aspergillus have higher chromium resistance than that of produced from Bacillus. The effect of L1 and L4 on wet blue and collagen shows that the L1 has more excellent performance, in which the molecular weight of functional protein is 48 KD. By SEM and MCT analysis, L1 can successfully disperse the collagen fibers of wet blue. Furthermore, the biodegradation rates of collagen and elastin were 0.006‰ and 0.5‰, respectively. It indicates that the acid protease mainly degraded elastin but not collagen in bating process thereby ensuring production safety. This paper provides the importance references for the application and the basis for the development of mechanism of acid protease in bating process. 

Recent Progress in Synthesizing Polyethers via Organocatalysts

Synlett ◽  
2021 ◽  
Author(s):  
Yao-Yao Zhang ◽  
Guan-Wen Yang ◽  
Guang-Peng Wu
Keyword(s):  
Molecular Weight ◽  
Recent Progress ◽  
Raw Materials ◽  
Catalytic Efficiency ◽  
Cost Effective ◽  
Catalytic Performance ◽  
Excellent Performance ◽  
Metallic Compounds ◽  
High Yields ◽  
Performance And Mechanism

Aliphatic polyethers are one of the most widely used polymers, whose synthesis is largely dependent on metallic compounds. Recent development of organocatalysts may break the limits of this long-standing field and infuse vitality into polyether production. In this Synpacts article, the recent advances of organocatalysts for polyether production is introduced in aspects of catalytic performance and mechanism. Moreover, attentions are paid to the latest contributions of bifunctional organoboron catalysts which can be prepared with high yields from cost-effective raw materials in two facile reactions and show excellent performance in the polyether production with remarkable catalytic efficiency, controllability on molecular weight, and explicit polymerization mechanism. Based on these advances, it is envisioned that new discoveries using organocatalysts will continue in the previsible future.

Preparation of n-Alkylacrylate and Vinyl Acetate Copolymer and Its Influence on Low-Temperature Fluidity of Diesel Fuel

2011 ◽  
Vol 236-238 ◽  
pp. 708-714 ◽  
Author(s):  
Hong An ◽  
Shu Gang Gao ◽  
Shuang Li ◽  
Yan Xin Xie
Keyword(s):  
Molecular Weight ◽  
Low Temperature ◽  
Vinyl Acetate ◽  
Diesel Fuel ◽  
Mass Fraction ◽  
Raw Materials ◽  
Cold Filter Plugging Point ◽  
Point Depressant ◽  
Petrochemical Company ◽  
Acetate Copolymer

The n-tetradecylacrylate-vinyl acetate copolymer (PPV) was prepared from n-tetradecylacrylate and vinyl acetate. The PPV was employed as pour point depressant to improve the low-temperature fluidity of the -20# diesel from Daqing Petrochemical Company. The result indicated that the solidification (SP) and the cold filter plugging point (CFPP) were affected largely by PPV. And when mass fraction of PPV -14(copolymerization conditions: 80 °C,w（benzoyl peroxide）1％（total weight of raw materials）, n（vinyl acetate）∶n（n- tetradecanolacrylate） = 4∶1 ) in diesel fuel was 0.1%wt, the SP reduced by 15.0 °C, the CFPP reduced by 6.0 °C simultaneously; We analysise the different molecular weight of PPV-14, and discover that the molecular weight of PPV-14 is ralated to the the low-temperature fluidity of the -20# diesel from Daqing Petrochemical Company. When mass fraction of PPV -14(molecular weight is 15000, distribution coefficient is 3.11) in diesel fuel was 0.1% wt, the SP reduced by 18.0 °C, the CFPP reduced by 7.0 °C, simultaneously.

scholarly journals Extraction and Characterization of Gelatin from Skin By-Products of Seabream, Seabass and Rainbow Trout Reared in Aquaculture

2021 ◽  
Vol 22 (22) ◽  
pp. 12104
Author(s):  
Jesus Valcarcel ◽  
Carolina Hermida-Merino ◽  
Manuel M. Piñeiro ◽  
Daniel Hermida-Merino ◽  
José Antonio Vázquez
Keyword(s):  
Molecular Weight ◽  
Rainbow Trout ◽  
Raw Materials ◽  
Gel Strength ◽  
Current Trends ◽  
First Case ◽  
Imino Acids ◽  
Increasing Demand ◽  
A Minor ◽  
By Products

The expansion of fish filleting, driven by the increasing demand for convenience food, concomitantly generates a rising amount of skinning by-products. Current trends point to a growing share of aquaculture in fish production, so we have chosen three established aquaculture species to study the properties of gelatin extracted from their skin: rainbow trout, commonly filleted; and seabass and seabream, marketed whole until very recently. In the first case, trout skin yields only 1.6% gelatin accompanied by the lowest gel strength (96 g bloom), while yield for the other two species exceeds 6%, and gel strength reaches 181 and 229 g bloom for seabass and seabream, respectively. These results are in line with the proportion of total imino acids analyzed in the gelatin samples. Molecular weight profiling shows similarities among gelatins, but seabass and seabream gelatins appear more structured, with higher proportion of β-chains and high molecular weight aggregates, which may influence the rheological properties observed. These results present skin by-products of seabream, and to a minor extent seabass, as suitable raw materials to produce gelatin through valorization processes.

scholarly journals Generality of Correlation between Yield and Reduced Mass of Raw Materials in Organic Reactions

2021 ◽  
Author(s):  
Masatoshi Kawashima
Keyword(s):  
Molecular Weight ◽  
Heat Capacity ◽  
Molar Heat Capacity ◽  
Raw Materials ◽  
Order Approximation ◽  
Product Yield ◽  
Rotatable Bond ◽  
Carbon Chains ◽  
Synthetic Reactions ◽  
Aliphatic Carbon

To validate a generality of the correlation between product yield and reduced mass of raw materials, the regression analysis of 129 reaction examples (55 as a sample size) including at least 66 types of reactions used in syntheses of natural products such as peptides and terpenes was conducted. It was possible to predict a yield of a variety of synthetic reactions for a synthesis of natural product with many aliphatic carbon chains by applying a reduced mass, adjusted with a molecular weight and the number of rotatable bond, to the regression equation. Moreover, it was found that the increase in yield due to a use of the adjusted reduced mass correlated with the harmonic mean of the molar heat capacity of raw materials and was expressed as a second-order approximation within the analysis range.<br>

scholarly journals Generality of Correlation between Yield and Reduced Mass of Raw Materials in Organic Reactions

2021 ◽  
Author(s):  
Masatoshi Kawashima
Keyword(s):  
Molecular Weight ◽  
Heat Capacity ◽  
Molar Heat Capacity ◽  
Raw Materials ◽  
Order Approximation ◽  
Product Yield ◽  
Rotatable Bond ◽  
Carbon Chains ◽  
Synthetic Reactions ◽  
Aliphatic Carbon

To validate a generality of the correlation between product yield and reduced mass of raw materials, the regression analysis of 129 reaction examples (55 as a sample size) including at least 66 types of reactions used in syntheses of natural products such as peptides and terpenes was conducted. It was possible to predict a yield of a variety of synthetic reactions for a synthesis of natural product with many aliphatic carbon chains by applying a reduced mass, adjusted with a molecular weight and the number of rotatable bond, to the regression equation. Moreover, it was found that the increase in yield due to a use of the adjusted reduced mass correlated with the harmonic mean of the molar heat capacity of raw materials and was expressed as a second-order approximation within the analysis range.<br>

DESIGNING BALANCED FEEDS FOR INDUSTRIAL AQUACULTURE USING PROTEIN HYDROLYSATES OF FISH BY-PASS RAW MATERIALS

Fisheries ◽  
2021 ◽  
Vol 2021 (4) ◽  
pp. 81-88
Author(s):  
Olga Mezenova ◽  
Dmitriy Pyanov ◽  
Svetlana Agafonova ◽  
Natalia Mezenova ◽  
V. Volkov
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Raw Materials ◽  
Protein Hydrolysates ◽  
Total Protein Content ◽  
Alternative Sources ◽  
Amino Acid Balance ◽  
Limiting Amino Acids ◽  
By Products

The perspective of the production of domestic compound feed for the development of industrial aquaculture in Russia is shown. Alternative sources of protein in mixed fodder for salmon and sturgeon have been investigated. The advantages of using protein hydrolysates instead of a part of fishmeal in compound feed are described. The advantages of protein hydrolysates from fish by-products are considered, the chemical composition and molecular fractional composition of sublimated protein hydrolysates obtained by enzymatic and thermal pathways from sardinella scales and ridges are studied. The presence in hydrolysates of 53.3 - 97.7% of low molecular weight peptides with a molecular weight of less than 10 kDa with a total protein content of 80.8-94.1% was established. Indicators of amino acid balance (scor) of hydrolyzates of scales and ridges of sardinella were calculated in relation to the established requirements for amino acids in salmonids. Indicators of amino acid balance (scor) of hydrolyzates of scales and ridges of sardinella were calculated in relation to the established requirements for amino acids in salmonids.It was found that the introduction of an enzymatically obtained hydrolyzate is more favorable for an increase in the content of limiting amino acids in mixed feed, and the use of sardinella scales for hydrolysis is more preferable than its ridges.

STUDY OF PROTEIN FRACTIONS OF HIGH-TEMPERATURE HYDROLYZATES OBTAINED FROM SMOKED SPRAT HEADS

Fisheries ◽  
2020 ◽  
Vol 2020 (2) ◽  
pp. 113-117
Author(s):  
Olga Mezenova ◽  
Vladimir Wolkov ◽  
Larisa Baydalinova ◽  
Natalia Mezenova ◽  
Svetlana Agafonova ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Chemical Composition ◽  
Raw Materials ◽  
Weight Fraction ◽  
Water Soluble ◽  
Protein Fractions ◽  
Raw Material ◽  
Organoleptic Characteristics ◽  
Pre Treatment ◽  
Peptide Fractions

The authors study three fractions obtained as a result of hydrolysis of smoked sprat heads (under temperature of 130oC and presser of 0.25 MPa) – fat, protein water-soluble, and protein-and-mineral ones. Waste from sprat production of two fish canning complexes of the Kaliningrad Region - “RosCon” and “Kolkhoz for the Motherland” - was used as raw material. Hydrolysis was carried out in an aqueous medium in two ways - with preliminary separation of fat and without this operation. The protein fraction was sublimated and its quantitative and qualitative indices were examined - mass yield, solubility, chemical composition and molecular fractional composition of the obtained peptide fractions were determined. The output of sublimated protein fractions is practically independent of the type of raw material and the method of pre-treatment and is 6.47.9% of the mass of raw materials. The chemical composition of protein fractions varies widely in terms of fat (1.4–8.3%), minerals (9.8–13.4%) and proteins (72.1–80.2%). The solubility of the peptide fractions ranged from 91-98%. The molecular weight assessment results showed a high content of a low molecular weight fraction of peptides with an MM of less than 10 kDa in all experimental samples (about 38%). This indicates a high digestibility and biological value of the obtained peptide compositions. Sublimated peptide compositions had typical organoleptic characteristics, pleasant aroma and taste of smoked fish. Ключевые

Biodiesel fuel synthesis by interesterification of triglycerides with carboxylate esters of low molecular weight

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Egle Sendzikiene ◽  
Violeta Makareviciene
Keyword(s):  
Molecular Weight ◽  
Raw Materials ◽  
Fatty Acid Esters ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Transport Sector ◽  
Biodiesel Fuel ◽  
Low Molecular Weight ◽  
Raw Glycerol ◽  
Biodiesel Synthesis

Abstract The ever-increasing environmental pollution from greenhouse gases motivates the search for methods to reduce it. One such method is the use of biodiesel fuels in the transport sector. Conventional biodiesel production generates up to 10% of a by-product, raw glycerol, whose amount continues to increase as biodiesel production volumes expand, but its demand remains limited. Recently, options have been analysed to replace the triglyceride transesterification process generally used in biodiesel production with an interesterification process that does not generate raw glycerol, instead yielding triacylglycerol that can be directly used as fuel for diesel engines by mixing with fatty acid esters. Additionally, triacylglycerol improves the low-temperature properties of fuel. The present article discusses triglyceride interesterification processes using various carboxylate esters of low molecular weight. Information is provided on raw materials that can be subjected to interesterification for biodiesel synthesis. The possible applications of chemical and enzymatic catalysis for triglyceride interesterification are discussed, and the influence of the catalyst amount, molar ratio of reactants, temperature and process duration on the effectiveness of interesterification is examined. The conditions and effectiveness of noncatalytic interesterification are also discussed in the article. Qualitative indicators of the products obtained and their conformity to the requirements of the European standard for biodiesel fuel are discussed.

scholarly journals Characterization of a Complex Mixture of Immunomodulator Peptides Obtained from Autologous Urine

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Alberto Fragoso ◽  
Mérida Pedraza-Jiménez ◽  
Laura Espinoza-González ◽  
María Luisa Ceja-Mendoza ◽  
Hugo Sánchez-Mercado ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Raw Materials ◽  
Complex Mixture ◽  
Size Exclusion ◽  
Exact Mass ◽  
Molecular Weight Range ◽  
Peptide Profile ◽  
Exclusion Chromatography ◽  
Chromatographic Profile ◽  
Peptide Profiles

A complex mixture of peptides plays a key role in the regulation of the immune system; different sources as raw materials mainly from animals and vegetables have been reported to provide these extracts. The batch-to-batch product consistency depends on in-process controls established. However, when an immunomodulator is a customized product obtained from the same volunteer who will receive the product to personalize the treatment, the criteria to establish the consistency between volunteers are different. In this sense, it is expected to have the same molecular weight range although the profile of peptide abundance is different. Here, we characterized the peptide profile of three extracts of an immunomodulator obtained from the urine of different volunteers suffering from three different diseases (i.e., allergic rhinitis, rheumatoid arthritis, and chronic rhinopharyngitis), using size exclusion chromatography (SEC) and mass spectrometry (MS). The peptides contained in the immunomodulators were stable after six months, stored in a refrigerator. Our results showed a chromatographic profile with the same range of low molecular weight (less than 17 kDa) in all analyzed samples by SEC; these results were also confirmed by MS showing an exact mass spectrum from 3 to 13 kDa. The fact that the peptide profiles were conserved during a six-month period at refrigeration conditions (2 to 8°C) maintaining the quality and stability of the immunomodulator supports the notion that it might be an alternative in the treatment of chronic hypersensibility disorders.

Synthesis and Evalution of Enteric Aqueous Polymethacrylate Coating Material

2013 ◽  
Vol 483 ◽  
pp. 56-60 ◽  
Author(s):  
Xiao Qi Chen ◽  
Chao Liu ◽  
Hai Jun Zhou ◽  
Xiao Lei Zhang ◽  
Fei Wang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Dissolution Rate ◽  
Methacrylic Acid ◽  
Chain Transfer ◽  
Raw Materials ◽  
Ethyl Acrylate ◽  
Coating Material ◽  
Chain Transfer Agent ◽  
Continuous Polymerization ◽  
Enteric Coated

A kind of enteric-coated pharmaceutical coating material, which can be dissolved in pH>5.5 medium, was successfully prepared by pre-emulsionsemi-continuous polymerization methods with equal molecular mass of methacrylic acid and ethyl acrylate as main raw materials. The effects of the initiator and chain transfer agent on the molecular weight and the performance of the emulsion were discussed. The obtained compound was used as the coating material of Lansoprazole capsule, and the dissolution rate was measured. The results show that polymethacrylat emulsion with 1.83×105 of molecular weight was obtained when the dosage of the initiator and the chain transfer agent is 0.43% and 0.79% of the total monomer mass, respectively. The dissolution rate of Lansoprazole capsule coated polymethacrylat emulsion in the pH 6.8 medium was greater than 75%.

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