Effect Of Enzyme Pretreatment Research Articles

Enzymatic pre-treatment in cold pressing: Influence on flaxseed, apricot kernel and grape seed oils

A commercial enzyme preparation consisting of pectolytic, cellulotic and hemicellulotic enzymes was applied to the oil extraction by cold pressing from apricot kernel, flaxseed and grape seed. The effects of enzyme pre-treatment varied depending on the different oil seed used as raw material. Although the increase in free fatty acidity can be considered as a negative effect (from 0.37 to 0.52), the decrease in peroxide number and p-anisidine values, increase in oil yield (22.75%), higher levels of total carotenoids and tocopherols, as well as a remarkable increase in phenolic content (x1.68) and radical scavenging effect (including hydrophilic and lipophilic-induced and total antioxidant capacity) showed that the use of enzyme application in the cold pressing of apricot kernel oil would be beneficial. Many of these positive results could not be achieved in the pressing of flaxseed or grape seed oils under the same conditions. A high negative correlation (r=-92.2) was found between p-anisidine value and δ-tocopherol for grapeseed oil. Hydrophilic and lipophilic antioxidant capacity, total phenolics, and total carotenoids negatively correlated well (r values above 80) with peroxide values for apricot seed oil. Correlation results showed that carotenoids play an important role in the oxidative stability of the oils, where it was much more evident for apricot seed oil (r=-97.5).

Enzyme pretreatment improves the recovery of bioactive phytochemicals from sweet basil (Ocimum basilicum L.) leaves and their hydrodistilled residue by-products, and potentiates their biological activities

In the present study, the effect of enzyme pretreatment on essential oil recoveries from sweet basil (Ocimum basilicum L.) leaves was evaluated. Moreover, the consideration on the use of hydrodistilled residue by-products as a source of bioactive phytochemicals with antioxidant, antimicrobial, and repellent effects against the stored-grain pest Tribolium castaneum was examined. Results showed that the enzymatic pretreatment increased the extraction yield of essential oil by 400, 417, and 478% in hemicellulase-, cellulase-, and viscozyme-treated samples, respectively. Phenylpropanoids including methyl cinnamate, methyl eugenol, eugenol and estragol were found as the main components, and were particularly abundant in cellulase-treated samples. From the hydrodistilled residue of enzyme-treated samples, better recoveries of total phenols (TPC) (258.3–470.9 mg GAE/g extract) and flavonoids (TFC) (59.4–94.3 mg QE/g extract) were observed. Using the DPPH, ABTS, and FRAP assays, a strong antioxidant activity of the rosmarinic-rich extract was observed. Such an activity which was mediated through electron transfer mechanism was highly correlated with the TPC, TFC and rosmarinic acid content. The in vitro bioassay showed that methanol extract (6.29 and 12.58 µL/cm2) had repellent activity against the stored-grain pest Tribolium castaneum. These results suggest the potential of enzyme pretreatment to promote the use of hydrodistilled residue by-products as a valuable source of natural antioxidants and repellents ingredients.

Effect of enzyme pretreatment on dehulling, cooking time and protein content of pigeon pea (variety BDN2).

This study was carried out to investigate the effect of enzymatic pretreatment at different enzyme concentration, incubation time, incubation temperature and tempering water pH on the hulling efficiency, cooking quality and protein content of pigeon pea (variety BDN2). Response surface methodology based on a four-factor, five-level, central composite design was employed to study the effect of the independent variables and optimize processing conditions. A quadratic model satisfactorily described the hulling efficiency, cooking time and protein content with high value for the coefficient of determination R2 (0.95, 0.92 and 0.97 respectively). It predicted a maximum hulling efficiency of 84.35%, minimum cooking time 13.06min and maximum protein content 22.60% at enzyme concentration, and 31.34mg/100g dry matter, incubation time, 8.72h, incubation temperature, 43.47°C and tempering water, pH 5.99. Results were also compared with hulling efficiency, cooking time and protein content obtained with traditional oil pretreated method 78.30%, 14.30min and 18.53% respectively. It revealed that hulling efficiency and protein content of enzyme pretreated pigeon pea could be increased 2.44% and 6.77% respectively, whereas cooking time could be reduced 1.50min compared to the oil pretreated method.

Effect of enzyme pretreatment in the ultrasound assisted extraction of finger millet polyphenols

Polyphenols from plant sources are increasingly recognized as functional ingredients with multiple health benefits. Finger millet (Eleusine coracana), a major millet grown in Asia and Africa is a significant source of polyphenols. The extraction of polyphenols from millets which are under-utilized has received less research attention compared to other plant matrices. Therefore, the present study was carried out to identify an effective method of extracting the polyphenols from finger millet (v. GPU 28) seed coat (FMSC). Two eco friendly methods namely ultrasonication (UA) and enzyme treatment followed by ultrasonication (EUA) were compared with the conventional heat reflux method (HR). The polyphenolic profile and content along with the antioxidant potential of the extract were evaluated. Phenolic yield increased 2.3 fold using EUA with xylanase (XUA) compared to heat reflux extraction (HR). However, yield with UA was equivalent to the conventional method. Total flavonoids increased 1.4 fold in UA and 1.3 fold in XUA, similarly, tannins also showed a significant increase (1.1 fold in UA and 1.2 fold in XUA). FTIR spectra revealed the presence of all phenolic functional groups and ESI-MS showed 80% similarity in the individual polyphenols in the extracts. Catechins, luteolin and cyanidin were identified in the UA and XUA treated samples, whereas, shikimic acid derivatives- caffeoyl and di caffeoyl were present only in XUA extracts. This is the first report on enhanced extraction of polyphenols from FMSC using a combination of enzyme treatment and ultrasonication, providing a green technology for utilization of polyphenols in nutraceuticals and functional foods.

Effect of enzyme pre-treatment on extraction yield and quality of fennel (Foeniculum vulgare) volatile oil

Abstract The effect of enzyme pre-treatment on extraction yield and quality of volatile oil of fennel seeds were evaluated using various enzymes viz., Celluclast, Pectinex, Viscozyme and Protease. Scanning Electron Microscopic (SEM) studies were conducted to visualize the effect of these enzymes on fennel seed cell walls. The quality of the oil was further evaluated using Gas Chromatography Mass spectroscopy (GC–MS). The enzyme pre-treatment resulted in an increase in yield of oil in the range of 11–22.5% as compared to the control sample. Scanning electron microscopic studies revealed a marked difference between the structures of fennel seeds treated with enzymes than the non-treated seeds. GC–MS studies revealed that the flavor composition of the fennel oil remains unchanged even after pre-treatment. From an economic perspective, the results of the present study could be used effectively in the spice industry to increase the extraction yield of volatile oil from fennel seeds.

Effect of enzyme pretreatment on yield and quality of fresh green chilli ( Capsicum annuum L) oleoresin and its major capsaicinoids

The effect of enzyme pretreatment on extraction yield and quality of oleoresin from fresh green chilli (Capsicum annuum L) samples and its major capsaicinoids were evaluated using various enzymes viz., Celluclast 1.5L, Pectinex Ultra SP.L, ViscozymeL, Protease and an equal combination of Celluclast 1.5L, Pectinex Ultra SP.L and ViscozymeL. Optimization of the enzyme activity was carried out by varying the enzyme concentration, reaction temperature, pH, and incubation time. The quality of the oleoresin was further evaluated using High Performance Liquid Chromatography (HPLC) coupled with Photo Diode Array (PDA) detector. Scanning Electron Microscopic (SEM) studies were conducted to visualize the effect of these enzymes on green chilli cell walls. It was observed that the capsaicinoids recovery was higher in ViscozymeL pretreated green chilli (22%) followed by chilli pretreated with enzymes Celluclast (20%) Pectinex (17.5%) and Protease (14%) with respect to the control sample. The HPLC finger printing of capsaicinoids showed no alterations in their profile as compared with the control sample. The SEM analysis revealed that the enzyme pretreatment, especially with enzymes ViscozymeL and Celluclast was potentially effective in rupturing the cell walls and making them more susceptible to extraction medium. In economic point of view, the results of the present study could be used effectively in the spice industry to increase the extraction yield and quality of oleoresin from green chilli.

Effect of enzyme pre-treatment on extraction yield and quality of cardamom (Elettaria cardamomum maton.) volatile oil

The effect of enzyme pretreatment on extraction yield and quality of volatile oil of cardamom seeds were evaluated using various enzymes viz., Celluclast 1.5L, Pectinex Ultra SP.L, ViscozymeL and Protease. Scanning Electron Microscopic (SEM) studies were conducted to visualize the effect of these enzymes on cardamom seed cell walls. The quality of the oil was further evaluated using Gas Chromatography Mass spectroscopy (GC–MS). The enzyme pretreatment resulted in an increase in yield of oil in the range of 7.23–7.83% as against 6.73% of the control sample. The enzyme pretreatment with ViscozymeL was proved to be most effective than all other tested samples. Scanning electron microscopic analysis of cardamom seeds revealed that the cell rupture in enzyme treated seeds are smooth and open due to the hydrolysis of cell wall compounds, whereas water treatment resulted only in structural damage. It was further observed that enzyme pretreatment facilitated the release of oil from oil glands without affecting the physico-chemical properties or flavor profile of the oil. GC–MS studies indicated that the flavor profile of cardamom oil contains the major flavor compounds viz., 1, 8 cineol and terpinyl acetate increased from 34.3 to 37.6% and 40.8–42.3% respectively with enzyme pre-treatment. In economic point of view, the results of the present study could be used effectively in spice industry to increase the extraction yield and quality of volatile oil from cardamom seeds.

Effects of enzyme pretreatment on the beatability of fast-growing poplar APMP pulp

Effects of enzyme pretreatment on the properties of fast-growing poplar APMP pulp were evaluated. Compared with the unpretreated pulp, the beatabilities of the pulp that had been pretreated by enzymes were improved significantly, such as a decrease of Canadian Standard Freeness (CSF) in the range of 25 mL to 55 mL, a decrease of PFI mill revolutions from 1000r to 5500r, and a decrease of beating energy consumption from 12.5% to 22.0%. The values of brightness, breaking length, tearing index, bursting index, and folding number of the pulp pretreated by cellulase were improved by 1.2%ISO, 23.7%, 14.8%, 14.6%, and 50% respectively, while that of the pulp pretreated by xylanase were respectively improved by 2.1%ISO, 16.8%, 8.8%, 8.9%, and 25%. The optimal enzyme dosages were 25 IU•g-1 and 25IU•g-1 for cellulase and xylanase, respectively. Fibre quality analysis results showed that the fibre length of pretreated pulp increased partly, fibre width and fines content decreased, fibres torsion increased, and fibre bonding got stronger. X-ray diffractometer analysis indicated that the degree of crystallinity of fibres increased after the enzyme pretreatment.

Enhanced sludge conditioning by enzyme pre-treatment: comparison of laboratory and pilot scale dewatering results

The effect of enzyme pre-treatment on dewaterability of anaerobically digested sludge was investigated at both laboratory and pilot scale. Our results revealed a significant increase in cake solid content (27% cake solids compared to 18% without enzyme pre-treatment), using an enzyme dose of only 20 mg/L. In order to assess practical application, enzyme pre-treatment was applied at the Wilmington, Delaware (U.S.) wastewater treatment plant, using a pilot-scale centrifuge. However, the efficiency reached in laboratory scale could not be obtained in pilot scale, where the final cake solids content did not exceed 20%. Centrifuge and belt filter press (simulated by Crown Press) dewatering were compared in terms of the process efficiencies in the absence and presence of enzyme pre-treatment. Possible factors that might cause the differences were tested by experimental and statistical comparisons. Results indicated that the higher shear applied in centrifugation is responsible for the lack of improved cake solids. The network strength of sludge determined by rheological measurements revealed that enzymatic treatment weakens the gel structure of the sludge floc through the hydrolysis of extracellular polymeric substances; this allows improved dewatering by filtration processes, but leads to floc deterioration when subjected to high shear during centrifugation.

Lysis of Tumor Cells by Antibody and Complement

Abstract The ascites form of a chemically induced guinea pig hepatoma, line-10, was resistant to killing in vitro by xenogeneic antibody and guinea pig complement. Pretreatment of line-10 cells with certain proteolytic enzymes rendered them susceptible to the killing action of antibody and guinea pig complement. The effects of enzyme pretreatment were dependent on enzyme concentration, temperature, and could be blocked by addition of competitive or non-competitive inhibitors. The effect of the enzyme treatment could be reversed by incubating the treated cells at 37°C (but not at 0°C), in the absence of the enzyme. Effective enzymes included ficin, bromelain, pronase, elastase, papain, trypsin, collagenase, lipases type I and type VI, and the neuraminidase preparation isolated from Clostridium perfringens. The activity of the lipase preparations and the neuraminidase preparation isolated from Clostridium perfringens appeared to be caused by proteolytic enzyme contamination. Enzyme preparations that proved ineffective in rendering the line-10 cells sensitive to killing by antibody and guinea pig complement included DNase, RNase, β-glucuronidase type 6A or type B10, hyaluronidase type V or type VI, and pectinesterase. Enzyme pretreatments that rendered the cells sensitive to killing by antibody and guinea pig complement also enhanced the sensitivity of the cells to the killing action and human complement. In addition the neuraminidase enzyme preparations from Vibrio cholorea or influenza virus increased the sensitivity of the line-10 cells to killing by antibody and human complement, but not to killing by antibody and guinea pig complement.