Enzymatic treatments

Owing to their complex structure and molecule size, enz nnes have an active site that is a region directly involved in the reactions. The enz5mie activity is based on binding a specific substrate, the enz5mie is supposed to react with to its active site. The element consists of a specific sequence ofamino acidresidues, which depends on the enz5mie type and the reaction that is to be catal3 ed [43]. 

Research on the possibility of the application of enz3mie technologies to the pulp and paper industiy has been the focus of interest of many researchers since the 50s of the 20th century. In 1959, it was found that traditional cellulose fiber treatment can be supplemented by enz5mies [69]. The main objectives of the application are reduction of the energy consumption required for the refining process and improvement of pulp properties [16, 30]. 

While there are several different groups of enz5unes, two of them at the present are mostly used for papermaking purposes cellulases and hemicellulases. Several tests confirmed the positive effect of enz5mies on fiber structure and manufactured paper [2]. 

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Extraction. Traditionally tea leaf is extracted with hot water either in columns or ketdes (88,89), although continuous Hquid soHd-type extractors have also been employed. To maintain a relatively low water-to-leaf ratio and achieve full extraction (35—45%), a countercurrent system is commonly used. The volatile aroma components are vacuum-stripped from the extract (90) or steam-distilled from the leaf before extraction (91). The diluted aroma (volatile constituents) is typically concentrated by distillation and retained for davoring products. Technology has been developed to employ enzymatic treatments prior to extraction to increase the yield of soHds (92) and induce cold water solubiUty (93,94). 

Delgado-Vargas, F. and Paredes-Lopez, Effects of enzymatic treatments of marigold flowers on lutein isomeric profiles, J. Agr. Food Chem., 45, 1097, 1997. 

However, since pectins can be methylesterified and/or acetylesterified, sections were treated on grid with an orange peel methylesterase to remove the methyl groups or with NaOH to remove both methyl and acetyl groups. After the enzymatic treatment, all the primary walls of most of the samples bind the... 

In apple processing, enzymatic treatment of the crushed fruit leads to a lower degree of degradation of the peel and the core than the rest of the fruit. Figure 1 shows the separate tissue zones in diagrammatic form. Their anatomic origins are different the epidermis and outer parenchyma zones are tissues derived from the fusion of the calyx, corolla and stamens of the flower the inner zones correspond to tissue derived from ovaries and carpels. The characterisation of the cell-wall material, especially pectins, from the different zones of the fruit may provide additional information on the possibility of finding uses for the discarded fractions. 

Enzymatic treatment in the extraction of cold-pressed lemon peel oils... 

In a recycling system, the aqueous discharge effluent from both centrifiiges is returned to the extractors for additional oil recovery, the water being reused. During this extraction process the viscosity of the emulsions increases because peel polysaccharides, mainly pectins, are transported with the emulsion. Enzymatic breakdown of the internal links of the pectin, catalysed by endopolygalacturonase activity, produces an important decrease in the viscosity of the emulsion [16]. In addition, enzymatic treatment removes pectins from the emulsion and contributes to it destabilization [17]. 

Improvement of debarking efficiency was measured as the decrease in energy comsumption in a laboratory scale debarker. The enzymatic treatments and the debarking were carried out as described earlier (Ratto et al 1993). 

A specific approach for the measurement of base damage to DNA involves the hydrolysis of DNA into monomeric units. Acidic hydrolysis leads to the release of bases while enzymatic treatment yields nucleosides. The resulting mixture of lesions together with the overwhelming presence of normal bases or nucleosides is resolved by chromatography. The targeted damage is then quantified by use of specific detection systems. 

In the experiment involving oxidative enzyme HRP (EC 1.11.1.7, RZ 1.9, 240 purpuro gallin (units/mg)) [89] for the enzymatic treatment and ultrasonic waves of 423 kHz and 5.5 W, the phenol degradation rate was found to increase. The ultrasound assisted biodegradation method has been found to be more efficient method than the sonolysis and enzyme treatment when operated individually. 

The reason for lack of microbial conversion of these molecules may be the difficulty in transporting them across the cell membrane. However, the possibility of an extracellular conversion exists. The enzymatic treatment of asphaltenes can be seen as an interesting alternative for the removal of heavy metals to reduce catalyst poisoning in hydrotreatment and cracking processes, for instance. 

Chemical, thermal, or enzymatic treatments are required to obtain analysable samples. Two typical methods used to achieve the hydrolysis of peptidic bonds are enzymatic and chemical catalysis [73]. The reaction times for enzymatic hydrolysis are long and typically lie in the range of 4 8 h [47]. Additionally, they demand purification procedures to get rid of the excess enzyme that could interfere in the protein identification. Due to these drawbacks, this method of hydrolysis finds limited use in the conservation science field. 

There are several chemical compounds found in the waste waters of a wide variety of industries that must be removed because of the danger they represent to human health. Among the major classes of contaminants, several aromatic molecules, including phenols and aromatic amines, have been reported. Enzymatic treatment has been proposed by many researchers as an alternative to conventional methods. In this respect, PX has the ability to coprecipitate certain difficult-to-remove contaminants by inducing the formation of mixed polymers that behave similarly to the polymeric products of easily removable contaminants. Thus, several types of PX, including HRP C, LiP, and a number of other PXs from different sources, have been used for treatment of aqueous aromatic contaminants and decolorization of dyes. Thus, LiP was shown to mineralize a variety of recalcitrant aromatic compounds and to oxidize a number of polycyclic aromatic and phenolic compounds. Furthermore, MnP and a microbial PX from Coprinus macrorhizus have also been observed to catalyze the oxidation of several monoaromatic phenols and aromatic dyes (Hamid and Khalil-ur-Rehman 2009). 

The pantothenate in blood and cerebrospinal fluid is conjugated without enzymatic hydrolysis no pantothenate activity is detected. In urine, pantothenate activity did not increase with enzymatic treatment. 

Modified starch Substance obtained by one or more chemical treatments of edible starches, which may have undergone a physical or enzymatic treatment, and may be acid or alkali thinned or bleached... 

For further purification, primary cultures of PBEC are passaged at the third day of culture by gentle trypsinization at room temperature. This enzymatic treatment selectively releases endothelial cells, leaving behind contaminating cells, such as pericytes and smooth muscle cells. Usually, contamination by nonendothelial cells should be below 1-3%. Endothelial cells are then seeded at a density of 30,000-50,000 cells/cm2 on rat-tail collagen-coated cell culture inserts (Figure 17.5). 

It is well accepted that the soluble fiber is the primary contributor for the beneficial health effects of psyllium especially the cholesterollowering activity, while the insoluble fiber may also have a contribution. The effects of solid-state enzymatic treatment on fiber contents were investigated for the modified psyllium. Shearzyme 500 L, Viscozyme L, and Pentopan Mono BG treatments all caused loss of soluble fiber under... 

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