DE4022867A1 - Removing pectin from extracted date juice and filtering - using ultrafiltration membrane, avoiding pectin splitting agents or filter aids - Google Patents

Abstract

In removal of pectin from extracted data juice, and filtration, without use of pectin-splitting agents or filter aids, the juice is filtered in one stage, at 0.1-1 MPa and 30-70 deg.C, in an appts. comprising ultra-filtration membranes of different materials and with cut-off limits of 5,000-50,000 Daltons, depending on the pre-treatment. Dimensioned tubes or capillaries are pref. used as the membranes, and ultrafiltration is pref. periodic and/or continuous or in one stage or cascades, according to the requirements of the complete date processing line. ADVANTAGE - Use of pectin-splitting enzymes or lime is avoided. The permeate is free from pectin and very clear, and the pectin-rich (3-5%) concentrate can be recyled or processed.

Description

The invention relates to a method for cleaning of extracted date juice without tools.

The most sensitive steps in making Date sugars are depectinizing and clear filtering pressed and extracted, quite contaminated sugar solution with high pectin content.

It is generally known that the sugar solution with high pectin content in a suitable reactor Using pectin-splitting enzymes (Röhm, Grinstedt fabrics te) dismantled and then after the corresponding stay the solution on frame filter presses using Filtering aids (bentonite or pearlite) almost clear is filtered.

The enzymatic breakdown requires a large amount pectin-splitting enzymes, this is about 0.1-0.3% of the treating sugar solution.

A temperature of is required for the function of the enzymes 45-50 ° C and a very precisely measured optimal enzyme concentration necessary, otherwise there is no complete Degradation, the solution remains contaminated by pectin or the Degrading enzymes lose their activity.

It follows from these statements that the pectin The most expensive and sensitive process in splitting Date sugar production is the quality of whose control of the date sugar occurring as the end product.

In other processes, e.g. B. according to the Hungarian Patent No. 1 65 076, the pectin cleavage takes place with the so-called called lime method. In these cases, the pectin is in shape precipitated by calcium pectate, then the redundant  Liquor neutralized with carbon dioxide and the corresponding pH adjusted. This poses a major problem the lime treatment in the solution forming high cation and Anion content, since this increases the strain on the date sugar production required ion exchange columns be significantly increased and thus the consumption of the resin and at the same time, the manufacturing costs increase.

After pectin cleavage with lime, that is also by using the auxiliaries already mentioned led frame filtering or vacuum drum filtering such.

The basis of the present invention is the cognition nis that with the help of with capillary or dimensioned Ultrafiltration units equipped with tubular membranes Unpectinate and clear filter in one step without Use of auxiliaries can take place.

In technology comes the one before extractor Date sugar solution in a common storage container, where with the help of a pump into the container of each Ultrafilter module rows arrived. The ultrafilter modules filter the date sugar solution to match the loading of the full range of date sugar production in a periodic or continuous or one-stage or cascade system by changing the filtering parameters to values of 0.1-1.0 MPa pressure and 30-70 ° C temperature are. As the cut-off limit of the synthetic ultrafilter membranes of capillary shape (hollow thread) or in the form of dimensioned tubes from the pretreatment of the dates a value between 5000 and 50,000 daltons to choose.

The resulting date sugar filtrate (permeate) is pec free of tin and has a clear purity. Those in the process  The resulting 3-5% pectin-rich concentrate can be added to the Starting point of the process traced back, roughly processed or used for other purposes.

In the process there are no pectin-splitting enzymes and other filter aids are used, and none items required for the technology of pectin cleavage and control units or for conventional technologies indispensable frame presses or vacuum drum filters operated.

The method according to the invention replaces the conventional two- or multi-stage processes (systems of pectin-splitting Reactor and filter) of depectinating by an Opera tion step. In the on the inventive method based cleaning of the extracted date juice can Sugar loss occurring during depectinization with lime of 20-30% can be switched off completely because the specified applied membrane filtration does not affect the pH.

The capacity of the economy of the date sugar production strongly influencing ion exchanger Pillars can be protected since none according to the invention foreign ions get into the solution. The membrane filtrate of the Date extracted with the technology of the invention juice is colloidal and in terms of dye content cheaper than with conventional methods.

The principle diagram and the process developed process of the multi-stage ultrafiltration device according to the invention are shown in Fig. 1.

The extracted date juice gets into the common container (T) with the help of a pump in the unit container ( 1 - n). After the booster and circulating pumps, the solution to be treated arrives at the Ultrafilter module rows (IN), where the pectinization and the clear filtration are carried out with the parameters already specified.

The pectin-free and clear date sugar solution arrives after appropriate control (A) in the ion exchanger system.

Fig. 2 shows the place of the ultrafiltration unit in the sugar production scheme.

example

In the process according to the invention, the extract date juice for 6 hours at 55 ° C and a pressure of 0.25 MPa in a batch mode ultrafilter capillary membrane containing ultrafiltration device cleaned. IN POROFILT modules were used in the ultrafiltration device UFTA-PSF-10-1.2 used. The cut-off limit the membrane was 10,000 daltons.

The filtrate was pectin-free and of clear purity. This was checked by means of an enzyme sample and turbidity tests.

Claims (3)

1. A process for depectinating and clarifying the extracted date juice, preferably for cleaning it, characterized in that the extracted date juice - without the use of pectin-cleaving and filtering aids - on an ultrafiltration membrane of various raw materials and with a cutting limit dependent on the quality of the pretreatment of 5000-50 000 Dalton ent device is filtered by the filtering process at a pressure of 0.1-1.0 MPa and a temperature of 30-70 ° C in one process step. 2. The method according to claim 1, characterized ge indicates that preferred as an ultrafiltration membrane wise dimensioned tubes or capillaries can be used. 3. The method according to claim 1, characterized ge indicates that the ultrafiltration - to the Needs of the complete date processing series fits - in periodic and / or continuous or in single-stage or cascade mode of operation.