scholarly journals Hydrolysis of tanned leather wastes under alkaline, acidic and oxidative conditions

2006 ◽  
Vol 60 (1-2) ◽  
pp. 23-26
Author(s):  
Tatjana Botic ◽  
Nadezda Iliskovic
Keyword(s):  
Molar Mass ◽  
Polypeptide Chain ◽  
Uv Spectroscopy ◽  
Leather Industry ◽  
Collagen Hydrolysate ◽  
Basic Step ◽  
Hydrolysis Temperature ◽  
Leather Wastes ◽  
Supporting Material ◽  
Hydrolysis Of

Different wastes in large quantities are the outcome or the by-product of processes in the tanning industry. The largest part of solid wastes is collagen based and obtained in the reprocessing steps of tanned and non-tanned products. The quality collagen substance obtained from wastes of the leather industry used as a supporting material in many reprocessing industries. Hydrolysis is the basic step of collagen processing, namely the shortening of its polypeptide chain. The main goal of this investigation was to examine the influence of the following parameters on the extent of collagen hydrolysis: type and quantity of reagent used for hydrolysis temperature of hydrolysis, pH, duration of hydrolysis as well as the dimensions of the "shavings" samples. The change of molar mass during hydrolysis was monitored by UV-spectroscopy. Special attention was paid to the dechroming process of the collagen hydrolysate.

Total control of chromium in tanneries – thermal decomposition of filtration cake from enzymatic hydrolysis of chrome shavings

2016 ◽  
Vol 35 (4) ◽  
pp. 444-449 ◽  
Author(s):  
P Kocurek ◽  
K Kolomazník ◽  
M Bařinová ◽  
J Hendrych
Keyword(s):  
Thermal Decomposition ◽  
Enzymatic Hydrolysis ◽  
Chromium Content ◽  
Leather Industry ◽  
Collagen Hydrolysate ◽  
Decomposition Products ◽  
Thermal Decomposition Products ◽  
Total Control ◽  
Magnesium Removal ◽  
Hydrolysis Of

This paper deals with the problem of chromium recovery from chrome-tanned waste and thus with reducing the environmental impact of the leather industry. Chrome-tanned waste was transformed by alkaline enzymatic hydrolysis promoted by magnesium oxide into practically chromium-free, commercially applicable collagen hydrolysate and filtration cake containing a high portion of chromium. The crude and magnesium-deprived chromium cakes were subjected to a process of thermal decomposition at 650°C under oxygen-free conditions to reduce the amount of this waste and to study the effect of magnesium removal on the resulting products. Oxygen-free conditions were applied in order to prevent the oxidation of trivalent chromium into the hazardous hexavalent form. Thermal decomposition products from both crude and magnesium-deprived chrome cakes were characterized by high chromium content over 50%, which occurred as eskolaite (Cr2O3) and magnesiochromite (MgCr2O4) crystal phases, respectively. Thermal decomposition decreased the amount of chrome cake dry feed by 90%. Based on the performed experiments, a scheme for the total control of chromium in the leather industry was designed.

scholarly journals Influence of Crosslinking Agent Concentration on The Microencapsulation Parameters of Collagen Hydrolysate-Walled Microcapsules

2018 ◽  
Vol 3 (2) ◽  
pp. 14
Author(s):  
Ahmet Aslan ◽  
Bugra Ocak
Keyword(s):  
Encapsulation Efficiency ◽  
Oil Content ◽  
Crosslinking Agent ◽  
Alkaline Media ◽  
Leather Industry ◽  
Collagen Hydrolysate ◽  
Lavender Oil ◽  
Definitive Solution ◽  
Leather Wastes ◽  
Great Pressure

Despite being a lot of discussion, a large amount of chrome tanned leather is still being tanned in the world. After tanning with chrome, chrome solid leather wastes occurred. These chrome wastes arise during mechanical processes such as trimming, shaving, buffing and splitting. These solid wastes containing trivalent chromium and may be oxidized to hexavalent chromium by the appropriate conditions in the landfill areas. Increasing environmental awareness and regulations have been making great pressure on the leather industry. Nowadays, solid leather wastes tanned with chromium are assessed by hydrolysis with the enzyme in high alkaline media and can subsequently be used for several applications. However, there is still no definitive solution to these chromed solid leather wastes. In this study, microcapsules of collagen hydrolysate cross-linked with glutaraldehyde containing Lavender essential oil were prepared by coacervation method. The influence of crosslinking agent concentration on the oil load (%), oil content (%) and encapsulation efficiency (%) of lavender oil microcapsules were investigated. As the crosslinking agent concentration increased, the oil load (%) decreased but oil content (%) and encapsulation efficiency (%) of microcapsules increased. The best result obtained by using 5 g of collagen hydrolysate, 7 ml of glutaraldehyde and 7 ml of lavender oil.

scholarly journals Influence of Crosslinking Agent Concentration on The Microencapsulation Parameters of Collagen Hydrolysate-Walled Microcapsules

2018 ◽  
Vol 4 (3) ◽  
pp. 12
Author(s):  
Ahmet Aslan ◽  
Bugra Ocak
Keyword(s):  
Encapsulation Efficiency ◽  
Oil Content ◽  
Crosslinking Agent ◽  
Alkaline Media ◽  
Leather Industry ◽  
Collagen Hydrolysate ◽  
Lavender Oil ◽  
Definitive Solution ◽  
Leather Wastes ◽  
Great Pressure

Despite being a lot of discussion, a large amount of chrome tanned leather is still being tanned in the world. After tanning with chrome, chrome solid leather wastes occurred. These chrome wastes arise during mechanical processes such as trimming, shaving, buffing and splitting. These solid wastes containing trivalent chromium and may be oxidized to hexavalent chromium by the appropriate conditions in the landfill areas. Increasing environmental awareness and regulations have been making great pressure on the leather industry. Nowadays, solid leather wastes tanned with chromium are assessed by hydrolysis with the enzyme in high alkaline media and can subsequently be used for several applications. However, there is still no definitive solution to these chromed solid leather wastes. In this study, microcapsules of collagen hydrolysate cross-linked with glutaraldehyde containing Lavender essential oil were prepared by coacervation method. The influence of crosslinking agent concentration on the oil load (%), oil content (%) and encapsulation efficiency (%) of lavender oil microcapsules were investigated. As the crosslinking agent concentration increased, the oil load (%) decreased but oil content (%) and encapsulation efficiency (%) of microcapsules increased. The best result obtained by using 5 g of collagen hydrolysate, 7 ml of glutaraldehyde and 7 ml of lavender oil.

scholarly journals A low-cost and water resistant biomass adhesive derived from the hydrolysate of leather waste

RSC Advances ◽  
2017 ◽  
Vol 7 (7) ◽  
pp. 4024-4029 ◽  
Author(s):  
Jianfei Zhou ◽  
Teng Xu ◽  
Xiaoling Wang ◽  
Chang Liu ◽  
Xuepin Liao ◽  
...  
Keyword(s):  
Coupling Agent ◽  
Silane Coupling Agent ◽  
Low Cost ◽  
Crosslinking Agent ◽  
Starting Material ◽  
Collagen Hydrolysate ◽  
Silane Coupling ◽  
Leather Wastes ◽  
Leather Waste

A low-cost and water resistant biomass adhesive was prepared by using collagen hydrolysate extracted from leather wastes as the starting material and silane coupling agent as the crosslinking agent.

scholarly journals Optimization of lupine hydrolyzate separation

2019 ◽  
Vol 292 ◽  
pp. 01026
Author(s):  
Jiří Pecha ◽  
Jakub Husár ◽  
Miloš Jelínek ◽  
Lubomír Šánek ◽  
Karel Kolomazník
Keyword(s):  
Mathematical Model ◽  
Mass Distribution ◽  
Molar Mass ◽  
Separation Process ◽  
Degree Of Hydrolysis ◽  
Optimal Conditions ◽  
Mixture Separation ◽  
Process Simulations ◽  
Promising Source ◽  
Hydrolysis Of

Lupine hydrolyzate is a promising source of proteins. Hydrolysis of lupine flour was studied under various conditions and their influence on reaction mixture separation by means of filtration was assessed. A mathematical model describing separation process was suggested and verified. This model was used in further calculations and process simulations. It was shown, that the filtration largely depends on the molar mass distribution, respectively the degree of hydrolysis. In addition, an approach enabling optimizing filtration was presented. The time of filtration performed at optimal conditions was almost ten times decreased.

Hydrolysis of trioxaadamantane ortho esters. I. Dialkoxycarbocation – ortho ester equilibrium and acidity function

1984 ◽  
Vol 62 (6) ◽  
pp. 1068-1073 ◽  
Author(s):  
Robert A. McClelland ◽  
Patrick W. K. Lam
Keyword(s):  
Acid Concentration ◽  
Intramolecular Interaction ◽  
Uv Spectroscopy ◽  
Equilibrium Constants ◽  
Hydrolysis Product ◽  
Acidity Function ◽  
Ortho Ester ◽  
Aromatic Substituent ◽  
Ortho Esters ◽  
Hydrolysis Of

3-Aryl-2,4,10-trioxaadamantane ortho esters (T) undergo a rapid equilibration with a ring-opened dioxan-2-ylium ion (DH+) prior to hydrolysis to product (a 1,3,5-cyclohexanetriol monobenzoate). The cation is stable in concentrated H2SO4 solutions where it has been characterized by nmr spectroscopy. It is observed using uv spectroscopy in dilute acids, and the ratio [DH+]/[T] at equilibrium has been measured as a function of acidity. Reversibility of the ring opening is established by the pattern of plots of cation absorbance versus acid concentration and by the observation that solutions containing cation on neutralization or dilution yield ortho ester, not hydrolysis product. Equilibrium constants for the reaction [Formula: see text] have been measured by obtaining the acidity function HT for this system. The effects of the aromatic substituent and the steepness of the acidity function plot versus acid concentration are interpreted in terms of a strong intramolecular interaction in the cation between the cationic center and the hydroxyl oxygen.

scholarly journals Adenosine 5′-tetraphosphate phosphohydrolase from yellow lupin seeds: purification to homogeneity and some properties

1997 ◽  
Vol 328 (1) ◽  
pp. 257-262 ◽  
Author(s):  
Andrzej GURANOWSKI ◽  
Elżbieta STARZYŃSKA ◽  
Paul BROWN ◽  
G. Michael BLACKBURN
Keyword(s):  
Divalent Cation ◽  
Polypeptide Chain ◽  
Lupinus Luteus ◽  
Nucleoside Triphosphate ◽  
Yellow Lupin ◽  
Ph Optimum ◽  
Single Polypeptide Chain ◽  
Lupin Seeds ◽  
Single Polypeptide ◽  
Hydrolysis Of

Adenosine 5ʹ-tetraphosphate phosphohydrolase (EC 3.6.1.14) has been purified to homogeneity from the meal of yellow lupin (Lupinus luteus) seeds. The enzyme is a single polypeptide chain of 25±1 kDa. It catalyses the hydrolysis of a nucleoside 5ʹ-tetraphosphate to a nucleoside triphosphate and orthophosphate, and hydrolysis of tripolyphosphate but neither pyrophosphate nor tetraphosphate. A divalent cation, Mg2+, Co2+, Ni2+ or Mn2+, is required for these reactions. The pH optimum for hydrolysis of adenosine 5ʹ-tetraphosphate (p4A) is 8.2, Vmax is 21±1.7 μmol/min per mg of protein and the Km for p4A is 3±0.6 μM. At saturating p4A concentrations, the rate constant for the reaction is 8.5±0.7 s-1 [at 30 °C, in 50 mM Hepes/KOH (pH 8.2)/5 mM MgCl2/0.1 mM dithiothreitol]. p4A and guanosine 5ʹ-tetraphosphate are hydrolysed at the same rate. Adenosine 5ʹ-pentaphosphate (p5A) is degraded 1/200 as fast and is converted into ATP and two molecules of orthophosphate, which are liberated sequentially. This contrasts with the cleavage of p5A by the lupin diadenosine tetraphosphate hydrolase (EC 3.6.1.17), which gives ATP and pyrophosphate. Zn2+, F- and Ca2+ ions inhibit the hydrolysis of p4A with I50 values of 0.1, 0.12 and 0.2 mM respectively.

scholarly journals OPTIMIZATION FOR BATCH PROTEOLYTIC HYDROLYSIS OF SPENT BREWER’S YEAST BY USING PROTEASES

2018 ◽  
Vol 54 (4A) ◽  
pp. 181
Author(s):  
Nguyen Thi Thanh Ngoc
Keyword(s):  
Ph Value ◽  
Degree Of Hydrolysis ◽  
Optimal Conditions ◽  
Brewer’S Yeast ◽  
Hydrolysis Time ◽  
Brewer's Yeast ◽  
Factors Influencing ◽  
Hydrolysis Temperature ◽  
Hydrolysis Of ◽  
Proteolytic Hydrolysis

The yield of proteolylic hydrolysis for spent brewer’s yeast by protease and aminoacid contents of hydrolysates (the main  factors influencing in taste of hydrolysed product) depends on factors influencing in catalytic activities of enzymes as temperature, pH value, type of used  enzymes and ratio enzyme/substrate. With the purpose to hydrolyse the spent brewer’s yeast for food application, bitterness of hydrolysate takes the firth consideration, and than the yield of hydrolysing process plays economic role. In this paper, it is dealt with determination of optimal conditions to obtain the highest yield of hydrolysis process and the lowest bitterness of hydrolysate (the bitterness is determined by sensory evaluation, expressed equivalently with concentration of quinine). Response surface methodology (RSM) was used to determine optimum condition for batch proteolytic hydrolysis of spent brewer’s yeast. The influencing factors were investigated as temperature (X1): 40 oC–60 oC; pH (X2): 6.0–9.0, ratio E (flavourzyme)/S (X3): 5–10 U/g and hydrolysis time (X4): 6–9 hours. The experimental responses including degree of hydrolysis (Y1) (%) and bitterness of hydrolysate (Y2) (μmol quinine/ml) are performed in second-degree model. The optimal conditions for obtaining high degree of hydrolysis and low bitterness are determined: Ratio of enzyme mixture (alcalase 7.5 U/g and flavourzyme 8.5 U/g), pH 7.5, hydrolysis temperature at 52oC and hydrolysis time 9 hours. Under the optimal conditions, the actual values obtained for the yield of hydrolysis was 40.81  ± 0.044 % and the bitterness equivalently with concentration of quinine was 16.37 ± 0.03 μmol quinine/ml.

scholarly journals Valorization of Cyprinus Carpio skin for biocompatible collagen hydrolysates with potential application in foods, cosmetics and pharmaceuticals

2021 ◽  
Author(s):  
Elena Danila ◽  
Raluca Stan ◽  
Mădălina ALBU KAYA ◽  
Georgeta VOICU ◽  
Maria Minodora MARIN ◽  
...  
Keyword(s):  
Cyprinus Carpio ◽  
Ph Value ◽  
Human Keratinocytes ◽  
Cd Spectroscopy ◽  
Random Coil ◽  
Collagen Hydrolysate ◽  
Bovine Collagen ◽  
Fish Collagen ◽  
Collagen Hydrolysates ◽  
Hydrolysis Of

Abstract Fish collagen is the safest source of collagen at present, the extraction being performed on secondary sources as skin, bones, scales or fins resulted after fish processing. The aim of the present study was to obtain biocompatible collagen hydrolysates from waste Cyprinus carpio skin, the main aquaculture species in Romania using an inexpensive and “green” neutral hydrolysis process. Neutral hydrolysis of pretreated fish skins performed for 6 hours at a temperature of 135°C and a pressure of 315 kPa produced collagen hydrolysates in 24.6-35.5% yields depending on the adopted pretreatment procedure. The extensive characterization of hydrolysate samples revealed a high purity degree (98% protein content, undetected ash content, pH value in the range 6-7), also confirmed by the absence of undesired aggregates in the characteristic fibril structure as determined by electronic microscopy. A specific collagen hydrolysate random coil structure and the absence of triple helix was determined by FTIR analysis and sustained by CD spectroscopy and X-ray diffraction. The biocompatibility assessment for the obtained fish collagen hydrolysates revealed no cytotoxic effect on Human keratinocytes, with an 80% cell viability, superior as compared to conventional bovine collagen hydrolysate.Neutral hydrolysis of waste Cyprinus carpio skin yielded collagen hydrolysates with determined characteristics and biocompatibility superior to bovine collagen, suitable for application in foods, cosmetics and pharmaceutical industry.

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