Pectolytic Enzyme Preparation Research Articles

Unlocking the potential of carrot pomace: Enzymatic and impact-disintegrator-activator processing for elevated beta-carotene concentration in carrot powder

Backgrounds: Carrot pomace is a by-product of the juice industry, which quickly spoils due to its high moisture content and is usually considered waste. However, it is a valuable product containing a significant amount of bioactive compounds, particularly carotenoids.Context and purpose of this study:In this study, we aimed to develop a technology for obtaining carrot powder from carrot pomace with an increased availability of beta-carotene. The unique aspect of the technology involved the use of enzymatic and impact-disintegration-activation processing (IDAP) of the raw material to enhance the release of beta-carotene from plant cells.Objective of this study:To achieve the goal, we have set objectives to compare various dosages of enzyme preparation and to evaluate devices for grinding carrots that can be used to make powder. At all stages, it was necessary to measure the amount of beta-carotene in the samples.Results: It has been found that the yield of carotenoids from carrot pomace is 185% higher compared to whole carrots. Moreover, the application of enzymatic and impact-disintegration-activation processing significantly increases the carotenoid yield in the powder by 17 times compared to carrots (200% in terms of dry matter). This remarkable result was achieved through the described processing method and the selection of the enzyme preparation. Additionally, the mechanoactivation obtained by using the Desi-15 disintegrator played a crucial role. It was also observed that the use of impact-disintegration-activation processing for further grinding of dried carrots can increase the beta-carotene yield by 8 times. Conclusions: The carrot pomace was processed, resulting in a fine-dispersed carrot powder that shows promising applications in the food or agricultural industries.Keywords: Carrot pomace, beta-carotene, impact-disintegrator-activator processing (IDAP), enzymatic processing, pectolytic enzyme preparations

THE APPLE PULP ENZYMATIC CATALYSIS

The paper presents experimental data on the use of pectolytic and cellulolytic enzymes and their compositions (Fructozym P6-L, Lafazym Extract, Cellolux-A) for processing the apple pulp from the Krasnoyarsky Snegirek fruits. The aim of this study is to select enzyme preparations for the processing of apple pulp, which allow to maximize the must yield, increase the content of phenolic compounds and provide high filtration rate. Technological and physico-chemical characteristics for the obtained wort samples are experimentally determined. It shown that the apple pulp treatment with a composition of enzyme preparations (Lafazym Extract + Cellolux-A) contributes to obtaining the maximum total must yield of 72.5% and the minimum kinematic viscosity of 2.64 mPa‧s. In addition, the maximum increase in filtration rate of 68.7% achieved by processing Lafazym extract. It established that the enzymatic catalysis of apple pulp makes it possible to increase the content of phenolic compounds in the must. It established that the enzymatic catalysis of apple pulp makes it possible to increase the phenolic compounds content in the must. Their highest concentration of 552.00 mg/cm3 obtained in the sample using an enzymatic preparation of pectolytic action – Lafazym Extract. It shown that the use of enzyme preparations affects to the optical characteristics of must samples. In relation to the control sample, the color intensity of the wort increases (from 0.740 to 1.102), while the yellowness index decreases (from 3.32 to 3.12), which indicates a decrease in the rate of wort oxidation reactions. The obtained results make it possible to recommend pectolytic enzyme preparations Fruktozym P6-L and Lafazym Extract in combination with Cellolux-A to use for the apple pulp processing.

Impact of traditional and innovative malaxation techniques and technologies on nutritional and sensory quality of virgin olive oil – A review

Virgin olive oil (VOO) nutritional and sensory quality depends on several aspects, including mechanical extraction technology: in this regard, malaxation conditions play a pivotal role since the major transformations linked to phenolic compounds (PC) and volatile compounds (VC) development and degradation take place during this step. Most of the reported studies state that malaxation should be carried out at temperature ranging 18–27°C for 30–40 min: this allows PC solubilization in the oil phase, the production of secoiridoid derivatives, and the development of aroma-active aldehydes, alcohols, and esters, limiting both PC losses and the generation of undesired VC. Reducing oxygen concentration in the headspace up to 5% helps to preserve the phenolic fraction, but slightly impairs VC generation. The use of pectolytic enzyme preparations and the application of innovative technologies like pulsed electric fields and ultrasound promote cell damages, and thereby the release of enzymes and micro-components. This review prioritizes the importance of further research aimed at defining specific optimization charts for each olive cultivar and maturity level, due to the relevant impact of genetics and agronomical factors. Furthermore, kneading conditions may be defined also depending on the desired quality of VOO, e.g., antioxidant power and/or bitterness level.

COMPLEX OF ENZYMES FOR EFFICIENT CONVERSION OF DRIED APRICOT BIOCOMPONENTS IN THE PRODUCTION OF FOOD INGREDIENTS FOR ALCOHOLIC BEVERAGES

The effectiveness of the use of pectolytic enzyme preparations - Fructocim P6L and fungal cellulase - Bruzaym BGX for biocatalysis of high-molecular substances of dried apricot pulp in the preparation of food ingredients (alcoholic juices and fruit drinks) for alcoholic beverages is shown.

IMPROVEMENT OF THE TECHNOLOGICAL MODES OF PRODUCING DRY WHITE TABLE WINES

By using the classical technology of making dry white wines, which does not involve maceration of the pomace, we can produce standard table wines, light and delicate. This minimises such an objectionable factor as saturation of the wine with extra nitrogenous and phenolic substances and oxidative enzymes. On the other hand, this scheme gives a specific varietal aroma no chance to reveal itself more expressively. The paper overviews briefly the scientific works considering the modes of pomace maceration before fermentation and the use of enzyme preparations in the technology of white table wines. The physicochemical and sensory characteristics of wine materials from Rkatsiteli grapes grown in the south of the Mykolaiv Region have been analysed. This analysis has proved that standard white table wine materials can be obtained both by the traditional method (the so called ‘white’ method) and with the use of short-term maceration of the pomace. Macerating the pomace resulted in obtaining fuller, richer wine materials with a bright aroma and good body. It has been shown that to obtain bright and not too blunt wine materials, the most essential parameter of the maceration process is its low temperature. A pectolytic enzyme preparation used during maceration increased, to some extent, the mass concentration of phenolic substances, the reduced extract, the optical density, and the concentration of terpene alcohols. Besides, it allowed fuller revealing a wine’s aromatic profile. The research has resulted in establishing that there is regularity in how the concentration of terpene alcohols changes with different temperature conditions of steeping the pomace. It has been shown that the maximum concentration of terpenes responsible for the varietal aroma is best retained in wine materials when the maceration temperature is 5°C. A rise in the pomace maceration temperature to 20°C led to a decrease in the concentration of labile terpene alcohols, so it should be avoided in producing quality wines. Studying different maceration modes has allowed recommending a certain method to manufacture full-bodied, well-structured white table wines with a pronounced varietal aroma. This method involves adding the enzyme preparation Depectil CLARIFICATION to the pomace and macerating it for 12 hours at 5°C.

Применение пектолитических ферментных препаратов в производстве напитков из плодов облепихи

Применение пектолитических ферментных препаратов в производстве напитков из плодов облепихи

Pectolytic enzyme reduces the concentration of colloidal particles in wine due to changes in polysaccharide structure and aggregation properties

To explore the effect of pectolytic enzyme application on polysaccharide size and colloidal interactions, rosé wines were prepared from pressed Shiraz grape juice, and red wines were made from the same juice by the addition of skins and seeds from fresh pressings. A pectolytic enzyme preparation containing primarily polygalacturonase and side-activities of arabinase and pectin lyase was used. Enzyme treatment enhanced the contribution of high molecular weight (≈ 200 kDa) polysaccharides rich in mannose and glucose (mannoproteins) and removed arabinose-rich polysaccharides of intermediate (≈ 40 kDa) size. Enzyme application reduced the molecular weight average of a class of smaller polysaccharides of approximately 6 kDa (rhamnogalacturonan II). All wines had similar particle sizes, but enzyme treatment markedly reduced particle concentration in wines, particularly in rosé wines. Wine polysaccharides were purified and when reconstituted in model wine, showed reduced particle concentration in response to enzyme treatment. Aggregation of polysaccharide in the presence of seed tannin was also markedly reduced by enzyme treatment. The results indicated that changes in structure introduced by the enzyme affected wine colloidal properties, potentially increasing polysaccharide solubility.

Grape pomace fermentation and cell wall degradation by Kluyveromyces marxianus Y885

Kluyveromyces marxianus Y885, an endopolygalacturonase (EPG) producing yeast, was evaluated for its capacity to hydrolyse the cell wall polymers of grape pomace as well as its general fermentation capabilities on this substrate. Small scale batch fermentations on autoclaved pomace inoculated with Y885 delivered 10 g/l ethanol and 7.7 g/l glycerol, the latter 14% more than a commercial wine yeast strain. When comparing the hydrolysis of the pomace cell wall by the Kluyveromyces EPG with that of a commonly used pectolytic commercial enzyme preparation, the polymer analysis confirmed that both the Y885 EPG and the commercial enzyme preparation primarily degraded surface exposed pectin polymers, while the hemicellulose-cellulose backbone was unchanged. High levels of galacturonic acid (GalA) monomers were generated by the commercial enzyme, whereas the Y885 EPG mostly liberated (polymeric) GalA-containing fragments together with low quantities of monomers. The Y885 strain produced strong pectinase activity throughout the fermentation process, whereas pectinolytic activity levels rapidly declined for the commercial enzyme after addition. The data obtained shows the evolution of pectin degradation during fermentation and provide compelling evidence that Y885 can utilise/valorise the grape pomace, and that the secreted enzymes (including an EPG) can effectively unravel the structural components of the grape cell walls.

Influence of Pectolytic Enzymes on the Quality of Wine Maceration

Obtaining high-quality wines with a registered designation of origin means making the most of the specific features of the variety and those imprinted with technology and the place of harvesting. The aroma is due to the chemical compounds of terpenic nature that accumulate in the grapes (variety flavors) and the secondary aromas that are formed during the alcoholic fermentation and the aging period of the wines (Amrani, and Glories, 1995). The wine-making of the varieties is followed by the appreciation of the primary grapes. This is achieved by preferential maceration of the must by means of enzymes (Marin et al., 1998). The technology of aromatic wines has two fundamental objectives: extracting the primary aromas of grapes (terpenols) and favoring the formation of secondary fermentation aromas. In order to obtain aromatic wines with variety typology, the preferential stage is decisive. Pectolytic enzyme preparations are used in oenology to accelerate and complete the extraction and clarification processes of the must, extracting and stabilizing the color, highlighting the varietal aromatic potential of the varieties and improving the filterability and maturation of the wines.

НОВЫЙ ОТЕЧЕСТВЕННЫЙ ФЕРМЕНТНЫЙ ПРЕПАРАТ ДЛЯ ВИНОДЕЛИЯ

A study into the effect of a new enzyme preparation Pectinol F-RKM 0719, used in the production of red table wines dur-ing maceration, was carried out. The investigated enzyme prepa-ration Pectinol F-RKM 0719 was previously isolated from the cul-ture liquid of the Aspergillus awamori F-RKM 0719 strain, ob-tained through multistage selection and mutagenesis at the De-partment of Biotechnology of the South Kazakhstan State Univer-sity named after M. Auezov. As a result of the development of a combined method of purification and isolation of a pectolytic en-zyme preparation, a preparation with a higher polygalacturonase activity was obtained having a sufficiently high yield of the desired product. The method is based on the sequential removal of individual groups of inactive impurities from the enzyme solutions using activated carbon and anion exchange resin. The use of hy-droxyapatite allows the activation of pectinases to be achieved by removing low molecular proteins. The absence of pectin substanc-es and carbohydrates makes it possible to use it in winemaking to clarify the best varieties of wine and remove the wine stone, which consists of the pectic substances of grape juice. The use of a new enzyme preparation in the process of maceration contributes to increasing the yield of mash from grape pulp, facilitating the pulp pressing and clarification of wine materials by reducing the vis-cosities and suspensions of the mash, as well as increasing the ex-traction of phenolic and colouring substances. The efficiency of enzymatic catalysis in the production of red table wines is demon-strated.

Influence of effectors pectin methylesterase alfalfa deesterification kinetics of pectin substances

The modern technology of food production enzyme preparations with pectolytic activity were used in technological operations of clarification of juices, as well as in the production of juices with pulp, which makes them indispensable in the processing of berries, fruits and vegetables. In basis of their use in technologies ability of deeterificashon lies and to depolymerize a pectin. The resulting pectin methylesterase herbaceous crops - alfalfa, possible to obtain an environmentally friendly preparation. One of the most important features of pectin methylesterase alfalfa enzyme preparation is the presence in its composition two catalytically active sites that, despite the high degree of homology differ in substrate specificity, affinity for inhibitors capable of activating cations. Influence of effectors by modifying the Michaelis constant and maximum reaction velocity as a result of the interaction of activators and inhibitors of the enzyme pectin preparation alfalfa as with the free form of the enzyme and to the enzyme-substrate complex. Experiments have shown that the resistance to the natural inhibitors of the enzyme preparation exceeds the data of microbiological origin of "Pectofoetidin P20х", which allows to increase the technological properties of the plant enzyme. An important fact is also that the Ca2 + ions and pyrocatechol widely present in fruit and vegetable raw materials, so the study and characterization of their influence on the behavior of pectolytic enzyme preparation with selective functional features, allowing to get low esterificated pectin, possessing both detoxifying and gelling properties, is the justification of the relevance research data. Thus, pectin methyl esterase enzyme alfalfa product most adapted to the biological system plant material, indicating that the high catalytic ability

Maceration procedures alternative to the standard vinification in red: the case of Nero di Troia wine

Maceration is an important step in vinification in red. The aim of this study was to assess the influence of four different maceration procedures on oenological parameters, phenolic profiles, and sensory characteristics of Nero di Troia wines. The comparisons were made among the following procedures: standard (15 days of maceration at 25 °C); cryo-maceration (24 h at 5 °C); addition of pectolytic enzyme preparation; and extended maceration (30 days of maceration at 25 °C). The pre-fermentative cryo-maceration allowed the obtainment of wines more alcoholic, less acid, and richer in proanthocyanidins than the standard wines. The enzymatic maceration caused an increase in proanthocyanidins content and LPP/SPP ratio, whereas the wines produced through extended maceration were low in alcohol, acetaldehyde, phenolics, and antioxidant activity. The type of maceration did not significantly affect the sensorial attributes. It is possible to obtain different red wines from the same grapes by applying different maceration procedures.

Contribution of enzyme preparations to the linalool content of wines made from the non-aromatic grapevine variety ‘Furmint’ (<em>Vitis vinifera</em> L.)

<p style="text-align: justify;"><strong>Aim</strong>: Terpene compounds were tentatively identified and quantified in musts and wines made from the non-aromatic grape variety ‘Furmint’ (<em>Vitis vinifera </em>L.) after individual treatments with seven different commercial enzyme preparations.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The identification and quantification of the terpene compounds were carried out with headspace solid phase microextraction (HS-SPME) coupled to gas chromatography-mass spectroscopy (GC-MS). The content of terpene compounds in the ‘Furmint’ grape pomace was below detectable level. After enzyme treatments [Lallzyme BETA (Lall), Rohavin VR-C (VRX), Rohapect VR-C (VRC), Rohavin MX (MX), Rohapect D5L (D5L), Endozym - Cultivar A (Cult. A) and β-glucosidase (Glucosidase)], only linalool was detected in semi-fermented musts, the must treated with β-glucosidase exhibiting the statistically highest linalool content (2.25 <em>μ</em>g/L). ‘Furmint’ wine produced from must treated with Lall appeared to be the most aromatic (based on sensory analysis) as well as the one with the highest linalool content (2.14 <em>μ</em>g/L).</p><p style="text-align: justify;"><strong>Conclusion</strong>: Wines produced from non-aromatic ‘Furmint’ grape pomace treated with different pectolytic enzyme preparations did not generally contain statistically higher levels of terpene compounds.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: This confirms the hypothesis that all enzyme preparations are not appropriate for every types of monovarietal grape pomace, especially regarding the increase of terpenic volatile compound contents.</p>

Comparison of effects of three commercial pectolytic enzyme preparations in white winemaking

Red grape mashes of Vranec were treated with differe nt pectolytic enzyme preparations. These treatments resulted in increase s on the organoleptic (colour) and rheologic characteristics (filterability, amounts o f solids that settled). The results of our experiments gives a comparison of the efficiency of preparations applicable in winemaking. Preparations Vinozym Vintage FCE and Tr enolin Rot DF showed a more intensive extraction of red grape pigments (anthocy anins) and increased colour intensity. The time of filtration was three times shorter, by using the enzyme preparations Vinozym Vintage FCE and Trenolin Rot DF compared to the con trol sample. By using the enzyme preparations Vinozym Vintage FCE, Rohapect VR-C and Trenolin Rot DF, the speed of desliming was twofold faster, compared to the contr ol sample.

The effect of pectolytic enzyme treatments on red grapes mash of Vranec on grape juice yield

Laboratory and industrial trials were conducted to evaluate the effect of pectolytic enzyme treatments on red grape mash of Vranec on grape juice yields. The red grape Vranec for laboratory trials were taken from private winery “Imako vino” Stip (Macedonia) and trials were conducted in their laboratory. The red grape Vranec for industrial trials were taken from private winery “Tristo” Veles (Macedonia) and trials were conducted in their winery. The grapes were weighed, destemmed, crushed and divided in 5 liters plastic reservoirs for laboratory trials, and for industrial trials were placed in a stainless steel fermentor (4t.). All treatments were performed in doublecate. Red grape mash made from Vranec were macerated for 6 hours at 18 to 20 oC with addition of one commercial pectolytic enzyme preparation (Vinozym Vintage FCE, Rohapect VR-C and Trenolin Rot DF). After addition of SO2 (50ppm) and yeast (Saccharomyces cerevisiae) NEUTRE SC (Lallemand, 2009)(200 mg/kg grape), maceration time of 5 days (~25 oC)was applied in order to study the effect of macerating enzymes on grape juice yields. After the maceration, the pomace was removed, in the obtained 4 different variations. Pectolytic enzyme preparation was not added to control trial. All treatments were performed in duplicate. Results of laboratory and industrial trials from our experiments, gives increased on free run juice yields by 4.85%-6.35% compared with non-treated mash of control trials.

Properties of family 79 β-glucuronidases that hydrolyze β-glucuronosyl and 4- O-methyl-β-glucuronosyl residues of arabinogalactan-protein

The carbohydrate moieties of arabinogalactan-proteins (AGPs), which are mainly composed of Gal, l-Ara, GlcA, and 4-Me-GlcA residues, are essential for the physiological functions of these proteoglycans in higher plants. For this study, we have identified two genes encoding family 79 β-glucuronidases, designated AnGlcAase and NcGlcAase, in Aspergillus niger and Neurospora crassa, respectively, based on the amino acid sequence of a native β-glucuronidase purified from a commercial pectolytic enzyme preparation from A. niger. Although the deduced protein sequences of AnGlcAase and NcGlcAase were highly similar, the recombinant enzymes expressed in Pichia pastoris exhibited distinct substrate specificity toward 4-Me-GlcA residues of AGPs: recombinant AnGlcAase (rAnGlcAase) substantially liberated both GlcA and 4-Me-GlcA residues from radish AGPs, whereas recombinant NcGlcAase (rNcGlcAase) activity on the 4-Me-GlcA residues of AGPs was very low. Maximum activity of rAnGlcAase hydrolyzing PNP β-GlcA occurred at pH 3.0–4.0, whereas the maximum rNcGlcAase activity was at pH 6.0. The apparent K m values of rAnGlcAase were 30.4 μM for PNP β-GlcA and 422 μM for β-GlcA-(1→6)-Gal, and those of rNcGlcAase were 38.3 μM and 378 μM, respectively. Similar to the native enzyme, rAnGlcAase was able to catalyze the transglycosylation of GlcA residues from PNP β-GlcA to various monosaccharide acceptors such as Glc, Gal, and Xyl. We propose that both AnGlcAase and NcGlcAase are instances of a novel type of β-glucuronidase with the capacity to hydrolyze β-GlcA and 4-Me-β-GlcA residues of AGPs, although they differ significantly in their preferences.

Loss of rutin and antioxidant activity of asparagus juice caused by a pectolytic enzyme preparation from Aspergillus niger

We found that a commercial pectolytic enzyme preparation from Aspergillus niger (pectinase AN) contained laccase activity that decreased rutin content and antioxidant activity of asparagus juice. This research investigated the effects of pH, temperature, and concentration of pectinase AN on pectinase AN’s laccase activity to decrease rutin content and antioxidant activity of asparagus juice. Asparagus juice was incubated with pectinase AN at different pHs (3.2, 4.5 and 5.8), temperatures (25, 37, and 50 °C) and enzyme concentrations (0.1%, 0.5% and 1%). Rutin content and antioxidant activity of samples was determined by HPLC and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) free radical method, respectively. The rate of loss of rutin and antioxidant activity of asparagus juice was smaller at pH 3.2 than at pH 4.5 and pH 5.8, smaller for 0.1% pectinase AN than 0.5% and 1% pectinase AN. The rate of loss of rutin of asparagus juice was greater at 25 °C than at the other two temperatures. Pectinase AN can decrease rutin content and antioxidant activity of asparagus juice at the selected conditions. But rutin content and antioxidant activity of asparagus juice produced using pectinase AN could be less decreased at pH 3.2 and 0.1% of enzyme with less than 2 h of incubation time. This information was helpful for juice industry to produce juices with high antioxidant activity using pectinase AN.

Enzyme-Catalyzed Change of Antioxidants Content and Antioxidant Activity of Asparagus Juice

A pectolytic enzyme preparation from Aspergillus niger (pectinase AN) decreased most rutin content and antioxidant activity of asparagus juice. To investigate the mechanism of such loss, we analyzed several possible related enzyme activities in pectinase AN. We found that the activity of pectinase AN to oxidize guaiacol had no significant difference with or without the presence of H2O2; thus it was laccase activity, not peroxidase (PO) activity, that pectinase AN contained. We did not find any polyphenol oxidase (PPO) activity in pectinase AN. Laccase in pectinase AN could be the major cause of loss of rutin and antioxidant activity of asparagus juice. When most laccase activity of pectinase AN was inactivated after heating at 70 degrees C for 1.5 min and incubated with asparagus juice, the loss rate of rutin was only 9% of that treated with unheated pectinase AN, and the antioxidant activity was even increased. Rhamnosidase activity was detected in pectinase AN and can change rutin in asparagus juice to quercetin-3-glucoside, which has higher antioxidant activity than rutin. This may explain the increase of antioxidant activity of asparagus juice treated with heated pectinase AN that still contained some rhamnosidase activity. The discovery of our research is helpful to produce juice with high antioxidant activity and high health benefits in the juice industry.

Mode of Action of β-Glucuronidase fromAspergillus nigeron the Sugar Chains of Arabinogalactan-Protein

A beta-glucuronidase purified from a commercial pectolytic enzyme preparation of Aspergillus niger hydrolyzed about half of the 4-O-methyl-glucuronic acid (4-Me-GlcA) residues located at the nonreducing terminals of (1-->6)-linked beta-galactosyl side chains of the carbohydrate portion of a radish arabinogalactan-protein (AGP) modified by treatment with fungal alpha-L-arabinosidase. Digestion of the alpha-L-arabinosidase-treated AGP with exo-beta-(1-->3)-galactanase released, by exo-fission of beta-(1-->3)-galactosidic bonds in the backbone chains of the AGP, neutral beta-(1-->6)-galactooligosaccharides with various chain lengths and their acidic derivatives substituted at their nonreducing terminals with 4-Me-beta-GlcA groups. In contrast, successive digestion of the alpha-L-arabinosidase-treated AGP with beta-glucuronidase followed by exo-beta-(1-->3)-galactanase liberated much higher amounts of beta-(1-->6)-galactooligomers together with a small portion of short acidic oligomers, mainly 4-Me-beta-GlcA-(1-->6)-Gal and 4-Me-beta-GlcA-(1-->6)-beta-Gal-(1-->6)-Gal. These results indicate that beta-glucuronidase acts upon 4-Me-beta-GlcA residues in long (1-->6)-linked beta-galactosyl side chains of the AGP, whereas short acidic side chains survive the attack of the enzyme.

Effect of Pectolytic Enzyme Preparations on the Phenolic Composition and Antioxidant Activity of Asparagus Juice

Commercial pectolytic enzymes were investigated for their influence on phenolics and antioxidant activities of asparagus juice. The antioxidant activity of asparagus juice was analyzed according to 2,2'-diphenyl-l-picrylhydrazyl and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) methods. The enzymes, with the exception of pectinase from Rhizopus sp., contained rutinase, which hydrolyzed rutin to quercetin. Asparagus juice treated with Viscozyme had the highest quercetin content without exhibiting a significant increase in the antioxidant activity. For a pectinase from Aspergillus niger, the antioxidant activity of asparagus juice was markedly reduced. Caution should be paid in the selection of pectolytic enzyme preparations for production of antioxidant activity-rich juice.