Wines & Juices
The Wine & Fruit Juice Industry
All types of fruit and berry of nutritional and industrial significance contain varying amounts of a substance called pectin which acts as a kind of glue holding plant cell walls together.
In the unripe fruit, pectin is present in its insoluble form, sometimes called protopectin, which is responsible for the hardness of the unripe fruit.
As the fruit ripens, this protopectin is partially broken down into a more soluble form and the structure of the fruit becomes softer.
Due to its partial solubility at this stage, some of the pectin passes into the juice during pressing, leading to an increase in viscosity and difficulties in obtaining optimal juice yields.
The extracted juice is low in colour and flavour components. Furthermore, it is difficult to clarify and filter.
The abovementioned difficulties can be overcome by adding special enzyme preparations to the fruit pulp (or mash) prior to pressing. This enzymatic mash treatment facilitates the release of the juice and leads to considerably improved juice yields and press capacity.
Complete depectinization by means of a suitable pectinase preparation ensures good clarification and filtration of the juices as well as good stability for the juice concentrates produced.
The application of mash enzymes in the processing of berries, grapes, apples and pears is standard practice today in most countries. The depectinization of the juices after pressing is necessary when making a clear juice. In the production of concentrated fruit juices, depectinization is necessary to prevent jellification during the concentration or storage of the concentrates.
Apple juice is one of the juices that can contain considerable amounts of starch, particularly at the beginning of the season. The starch must be degraded in the production of clear juices and/or concentrates. This is achieved by adding starchsplitting enzymes together with the pectinase during depectinization of the juice.
In some cases, the addition of other enzyme preparations such as cellulases may also lead to improved juice yields and better colour extraction. If, for example, berries are processed, optimal colour extraction is a priority because colour is an important quality parameter for these juices.
The polysaccharide araban (a polymer of the pentose arabinose) is an important part of fruit cell walls and may cause haze in fruit concentrates.
With modern fruit juice technology pushing yields higher and higher, considerable amounts of araban are often extracted from the cell walls and the risk of araban haze has increased during the last few years.
Unfortunately, the haze appears only some time after the juice has been concentrated and it is difficult to predict because there aren’t any convenient analytical tests that can be performed prior to concentration.
To safeguard against the formation of haze in the concentrate, Novozymes’s pectinase preparations recommended for juice depectinization contain sufficient arabanase activity.
Enzymes for the citrus industry
Special pectolytic enzyme preparations (Citrozym®, Citropex™) are used in the citrus industry. In the pulp wash process, enzymes are used to reduce viscosity in order to avoid jellification of pectin during concentration.
Tailor-made pectolytic enzymes are used for the clarification of citrus juices (particularly lemon and lime juice), for the recovery of essential oils and the production of highly turbid extracts from the peels of citrus fruit. These cloudy concentrates are used in the manufacture of soft drinks.
The enzymatic peeling of citrus fruit is a relatively new application for the production of fresh peeled fruit, fruit salads and segments. Enzymatic treatment with Peelzym™ results in citrus segments with improved freshness as well as texture and appearance compared with the traditional process using caustic soda.
Special enzymes for winemakers
The ideal enzyme preparations for winemaking are different to those for fruit juice processing. In winemaking, very specific enzyme activities are required in order to obtain the desired effect while at the same time ensuring the best quality.
In fruit juice processing, the enzymes are inactivated very shortly after they have done their job, for example by pasteurization. In winemaking, no such heat treatment takes place. The enzymes therefore maintain their activity over a longer period. Side activities that may be beneficial for fruit juice processing can be less desirable for winemaking as they may negatively influence wine quality during storage. Specific enzyme preparations for winemaking have been developed in order to improve wine quality while at the same time bringing about the desired technological advantages.
In winemaking, one aim is to extract as many flavour compounds as possible. In the case of red wine, colour extraction is also very important.
One problem very specific to winemaking is the extremely difficult clarification and filtration of wines made from grapes attacked by the fungus Botrytis cinerea. The Botrytis fungus produces betaglucans (polymers of glucose with a high molecular weight) which pass into the wine. These large molecules hinder clarification and rapidly clog filters. The troublesome betaglucans can easily be removed by adding a highly specific betaglucanase to the wine.
Research into the chemical composition of grapes is opening up new enzyme applications. One example is the Novozymes enzyme Novoferm® 12 for aroma liberation. The glycosidases in Novoferm 12 hydrolyze terpenyl glycosides (also known as bound terpenes) found in grapes. Terpenes are released and these are one of the important constituents of the bouquet. Winetasters can usually detect a noticeable improvement in the bouquet after treatment with Novoferm 12.
The standard Product Ranges for the Wine, Fruit Juice and Citrus industries look as follows. Most products are available in liquid as well as solid form, and in different concentrations. Please contact your local sales office for further details as well as with inquiries about special products not listed here.
Please note that all products listed are not necessarily available in all countries. Contact your local sales office for details.
A unique pectinase preparation for grape maceration in red wine making.
A highly purified pectinase preparation for grape maceration in white and rosé wine making.
A highly concentrated purified pectinase preparation for must clarification in white and rosé wine making.
A highly concentrated pectinase preparation for clarification and thermovinification in red wine making.
A special blend of pectinase and beta-glycosidase activities for aroma enchancement in young wines.
A unique blend of pectinase and beta-glucanase activities for improvement of aging and filtration in young wines.
A highly specific beta-glucanase preparation for improvement of filtration of young wines with Botrytis glucan.
Pectinex® Ultra SP
Variety of different pectinases containing a range of hemicellulotic side activities. Used for apple and pear mash treatment resulting in higher yield and capacity.
Pectinase preparations with a relatively broad spectrum of side activities such as cellulases and hemicellulases used for enzymatic pomace treatment to increase yield.
A combination of pectintranseliminase, polygalacturonase and pectinesterase with arabanase side activity in various strengths for juice treatment.
Starch Degradation of Juice
An amyloglucosidase for hot treatment of juice to break down the starch.
A pectinase preparation with rhamnogalacturonase side activity to increase the filterability (ultra and microfiltration) of juice.
Pectinase preparation with a pH spectrum particularly well suited to berries which maximixes yield and improves colour extraction.
A multi-active enzyme preparation used as a cleaning agent to remove colloids from membranes.
A unique cellobiase preparation which prevents the formation of cellobiose in fruit juice concentrate.
A unique hemicellulase-pectinase for improved recovery of citrus essential oils.
A tailor-made pectinase preparation for extraction and viscosity reduction in cloudy citrus juices.
A concentrated pectinase-hemicellulase for viscosity reduction in clear juices.
A pectinase-arabanase for lemon juice clarification.
An enzyme preparation for enzymatic peeling of citrus and other fruits.