WO2005070234A1

WO2005070234A1 - Process for the production of sediment free clarified fruit juices

Info

Publication number: WO2005070234A1
Application number: PCT/IB2003/006171
Authority: WO
Inventors: Tumkur Ramachandriah Shamala; Sirivara Venkataramaiah Basavaiah; Gundo Jivaji Joshi
Original assignee: Council Of Scientific And Industrial Research
Priority date: 2003-12-23
Filing date: 2003-12-23
Publication date: 2005-08-04
Also published as: AU2003288629A1; BR0318638A

Abstract

The present invention relates to an improved process for the production of sediment free clarified fruit juices and the main usage of the invention will be in the quick enzymatic processing of fruit pulp from banana, litchi and guava to a completely clarified juice, which is free from any sedimentation after bottling.

Description

PROCESS FOR THE PRODUCTION OF SEDIMENT FREE CLARIFIED FRUIT JUICES Field of the invention

The present invention relates to an improved process for the production of sediment free clarified fruit juices. The main usage of the invention will be in the quick enzymatic processing of fruit pulp from banana, litchi and guava to a completely clarified juice, which is free from any sedimentation after bottling.

Background and prior art

Reference may be made to a patent on "Banana processing" by P. Sole (1991), USPTO RE 34237 wherein banana juice is obtained by enzymic processing of pulp of completely ripe banana; evaporation of flavour to prepare concentrated de-flavored banana juice. The draw back would be that the resulting product would be devoid of flavour.

Reference may also be made to a patent from CFTRI, Mysore, relating to a process on the production of fungal enzyme concentrate and its application in fruit processing by Sreekantiah, K.R., Jaleel, S.A., and Ramachandra Rao, T.N. (1968), patent No. 115537 wherein the banana pulp is enzymatically hydrolysed using an enzyme prepared in the laboratory, the drawback here is the availability of the enzyme for fruit processing.

References may also be made to various papers published from CFTRI, Mysore, such as:

1). Use of pectin degrading enzymes in the extraction and clarification of fruit juice (1963) by Sreekantiah, K.R., Shastry, M.C.S., Johar, D.S., Rao, T.N.R., and Bhatnagar, H.C.,

Food Science, 12, 364.

2). Preparation of liquid fruits by enzymic processing (1968) by Sreekantiah, K.R., Jaleel,

S.A., and Rao, T.N.R., J. Food Sci. Technol., 5, 129.

3) Utilization of fungal enzymes in the liquefaction of soft fruits and extraction and clarification of fruit juices, (1971) by Sreekantiah, K.R., Jaleel, S.A., and Rao, T.N.R., J.

Food Sci. Technol. 8, 201 -203.

4). Nature and application of pectinasses with special reference to fruit and vegetable processing industry (1975) by Sreekantiah, K.R, Indian Food Packer, 29 (40), 22-36.

5). Development studies on certain aspects of enzymic processing of banana (Musa cavendishii) 1. Laboratory investigations (1978) by Jaleel, S. A., Basappa, S.C, and

Sreekantiah, K.R., Indian Food Packer, 32 (2), 17-21.

6). Developmental studies on the enzymatic processing of banana (Musa cavendishii), II, Pilot scale investigations (1979) by Jaleel, S. A., Basappa, S.C, and Sreekantiah, K.R.,

Indian Food Packer, 33 (1), 10-14., wherein the pulp of completely ripe banana was homogenized, the puree was heated to

70° C in the presence of 212 mg potassium metabisulphite/kg pulp followed by cooling of the pulp to 40°C, adding required quantity of pectinolytic enzyme concentrate prepared in the laboratory, hydrolysis of the pulp up to 18 h, pressing through cheese cloth, settling of the sediment in cold overnight, filtering through paper pulp and bottling of the clarified product at 70° C. The drawbacks of these processes are 1) Lengthy processing of the fruits to juice 2) Haze or precipitate formation of the clarified product would occur sometimes during bottling or storage.

Object of the invention

The main objective of the present invention is to provide an improved and quick process for clarification of fruit juices.

Yet another objective of the present invention is to find out the suitability of various banana varieties and other soft fruits such as litchi and guava for the preparation of the clarified juice under improved method.

Still another objective of the present invention is to additionally use cellulases for clarification.

Summary of the invention The present invention relates to an improved process for the production of sediment free clarified fruit juices. The main usage of the invention will be in the quick enzymatic processing of fruit pulp from banana, litchi and guava to a completely clarified juice, which is free from any sedimentation after bottling.

Detailed description of the invention Accordingly the present invention provides an improved process for the production of sediment free clarified a fruit juice, which comprises the steps: a) preparing a pulp of fruit; b) adding preservatives in the range of 0.2g -0.3g/ kg of pulp to the pulp of step (a) while the preparing a pulp process is on; c) treating the pulp obtained from step (b) with pectinolytic enzyme having an activity of 600-1200 units/kg of pulp at a temperature in the range of 30°C-40°C; d) holding the enzyme treated pulp for a period of 3-5hrs at a temperature in the range of 30°C-40°C; e) filtering the above obtained hydrolysate to get a clear juice; f) optionally adding cellulase enzyme in the range of 0.05% v/v to juice obtained from step (e) for additional clarification, followed by raising of temperature in the range of 50-60° C for a period of 30-60 minutes, g) heating the enzyme treated juice obtained from steps (e) and (f) at a temperature in the range of 70-85°C for a period of 5-15 min followed by cooling the juice to a temperature in the range of 10-15 C, h) filtering the juice under vacuum to obtain sediment free clarified fruit juice. In an embodiment of the present invention most of the banana varieties available may be used for juice preparation.

In another embodiment of the present invention, the fruit pulp, which is blended, may be hydrolysed by commercial pectinolytic enzyme such as Pectinase ultra spl (Novozyme), at 600-1200 pectinase units/kg of pulp. Yet in another embodiment of the present invention hydrolysis by commercial pectinases may be effective from 3 h to 5 h at 30° C - 40° C.

Still in another embodiment of the present invention the juice separated from the residual pulp may be heat processed at 70-80° C for 10-15 min. Prior to this for better clarification, cellulase (100-300 units/L juice) may also be optionally added to juice separated from residual pulp, heated to 40-55° C for 1-2 h and then temperature may be increased to 70- 85° C for 10-15 min. The heat processed juice may then be cooled to 10-15° C and clarified under vacuum.

In this process completely ripe fruits including banana, guava and litchi are weighed, peeled (as applicable), and weight of the pulp and wastage are recorded. Guava is weighed and used without peeling. The pulp is ground to a paste without the addition of water in a warring blender in the presence of potassium metabisulphite (200-300 mg/kg pulp). Commercial pectinase enzyme, such as Pectinex ultra spl (Novozyme) is mixed at 400- 1200 unit activity/kg pulp and enzyme is allowed to act at temperature of 30 -40° C for 3-5 h. The juice is filtered through cheesecloth and the volume of juice and weight of the residue are recorded. For further clarification, the juice is processed alternatively as follows: a) The temperature of the juice is increased to 70°-80° C for 10-15 min, cooled immediately and clarified twice by filtration through cellulose filter pads under vacuum, b) For better clarification, 0.5-1 ml of cellulase/1 (celluclast 1.5L, Novozyme) is added to the juice and it is heated up to 55° C and held at that temperature for 30-60 min and then temperature is increased to 70°-80° C for 10-15 min, cooled immediately and clarified twice by filtration through cellulose filter pads under vacuum. The juice hence obtained is free from any sediment. Yet in another embodiment of the invention, for further clarification optionally cellulase enzyme is adding in the range of 0.05% v/v to juice obtained, followed by raising of temperature in the range of 50-60° C for a period of 30-60 minutes

Novelty of the invention is that fruit pulp of banana, litchi and guava is processed quickly to a highly clarified juice without haze formation in the product by application of suitable hydrolytic enzymes, controlled and programmed heat treatment schedule for processing. The juice after initial clarification still carries remnants of cell wall material, which is not visible in the clarified juice but coagulates and precipitates due to the heat applied for bottling followed by cooling and results in the formation of the haze. The cell wall, which contains cellulose, hemicellulose, protein and pectin collapses completely on treatment with cellulase because of hydrolysis of cellulose microfibrils which are cross linked to these components, resulting in coagulation and heavy precipitation after heat and cold cycle. Hence cellulase treatment can also be effectively used to aid in the formation of the precipitate, which can be filtered from the juice.

BRIEF DESCRIPTION OF THE TABLES Table 1: Effect of temperature program on sediment formation in bottled juice

Table 2: Analysis of clarified juice before bottling:

Table 3: Changes in optical density and colour units after 2 months of storage.

Table 4: Effect of cellulase on banana juice obtained after pectinase treatment

Table 5. Analysis of juices obtained from various varieties The following examples are given by way of illustration of the present invention and therefore should not be constated to limit the scope of the present invention.

EXAMPLE 1

In this experiment 14 kg of ripe banana (Musa cavendishii) was manually peeled, 4.9 kg of peel and 9.1 kg pulp were obtained. The yield of pulp was 65% of the total fruit used. The pulp was mixed with potassium metabisulphite at the rate of 212 mg/kg of pulp and blended in a warring blender. The pulp was hydrolysed by commercial pectinolytic enzyme (800 u/kg pulp) such as Pectinex ultra spl (Novozyme, India) at room temperature of about 30 ° C for 3 h and filtered through cheesecloth to separate the liquid portion (7.9 kg) from the solid residue (1.1kg). To find out the effect of heating on sediment formation in the clarified juice during bottling, one liter of the juice obtained was filtered through cellulose pad under vacuum and distributed in 200 ml portions. These samples were individually heated at 65, 70, and 75° C, cooled, filtered as mentioned above and optical density (O.D.) was measured at 620 nm. The clarified juice was bottled individually at 65, 70 and 75° C, and O.D. was measured again after cooling. Data in Table 1 indicate that it is essential to maintain lower temperature for bottling in relation to the processing temperature. Table 1

Remaining portion of juice that was obtained by filtration through cheesecloth was processed at 75° C, cooled immediately and filtered through cellulose pad under vacuum. The clarified juice was analyzed for pH, ° Brix, acidity (by titration against 0.1 N NaOH), clarity (O.D. measurement at 620 nm in Shimadzu UV-160-Spectrophotometer, Japan), and colour measurement (Hunter lab/2° view angle/cc illuminant, Colour operating systems, model Lab scan XE). The results obtained are recorded in Table 2. Table 2 Parameters Values pH 4.74 °Brix 22.37 Acidity (%) 0.35 O.D. at 620 nm 0.034 Colour values: L 71.02 a -2.13 b 6.84 The juice was bottled at 70° C and the bottles were stored in duplicate at 10° C, room temperature (30° C) and at 45° C. After a storage period of 2 months at the above-specified temperature, the juices were analyzed for possible changes in optical density and colour measurements as mentioned above and the results were recorded (Table 3). For maintenance of colour however cold storage was feasible and darkening increased with increase in temperature from room temperature to increased temperature of 45° C. Table 3:

Parameters Storage Values O.D. at 620 nm 10° C 0.030 RT 0.034 45° C 0.034

Colour values 10° c L 68.38 a -3.15 b 13.70 RT L 66.80 a -4.48 b 20.47 45° C L 65.92 a -6.56 b 30.46

EXAMPLE 2

Experiment was carried out using 12.2 kg of ripe banana fruits (Musa cavendishii). The weight of peel and pulp obtained were 3.5 kg and 8.7 kg, respectively. The pulp was mixed with potassium metabisulphite at the rate of 212 mg/kg pulp and blended in a warring blender, enzymatically hydro lysed, and juice was filtered as mentioned in example 1. The filtered juice (7.2 1) was divided into two portions. Cellulase (Celluclast 1.5 L, 700 units/ml, Novozyme) was added (0.05% v/v) to one of them and other was used as a control. The juices were heated up to 55° C and held at that temperature for 30- 60 min and then the temperature was increased up to 80° C and held for 15 min, cooled and O.D. (620 nm) was recorded. Sediment from 200 ml portion of the juice was collected by centrifugation at 6000 rpm. The washed sediment was dried to a constant weight and hydrolysed by trifluroacetic acid method, neutralized and reducing sugar concentration was assayed. Sediment was removed from the remaining juice by filtration through cellulose pads under vacuum. Elemental analysis (sodium, calcium, potassium), pH, °Brix were analyzed in the clarified samples (Table 3). Juice was filtered through cellulose pad under vacuum and bottled at 70° C Table 4

*Pectinase treated, and then treated with/without cellulase, heated up to 80° C, cooled and measured before clarification. Other analyses were done after clarification.

**Clarified after treatment, bottled at 70° C, cooled and O.D. measured

The results indicated that the dry weight of the sediment obtained for control and cellulase treated samples were 4 and 12mg%, respectively. In the sediment of the control sample reducing sugar concentration was 37.5% of the residue whereas its concentration was 2.6% in the residue obtained after cellulase treatment. Heavy precipitation in cellulase treatment and low concentration of reducing sugar in its residue indicated that the hydrolysis of cellulose from the remnants of cell wall material exposes the hemicellulose, pectin and protein which can be easily coagulated by heating followed by cooling and removed by filtration. Data regarding the main minerals in control and cellulase treated juice indicated that concentration of these components did not alter much during the treatments. The cellulase treated juice was more clear compared to control. EXAMPLE 3 Different varieties of banana available locally were processed in 2 kg batches. Pulp was blended, mixed with 212 mg of potassium metabisulphite/kg, hydrolyzed at room temperature (about 30° C) for 3 h and filtered through cheesecloth. The filtrate was heated to 75° C cooled and filtered through cellulose pad under vacuum. The clarified juice was bottled at 70° C. Juices were analyzed as indicated under example 1. Table 5

From the results it was evident that the juice could be obtained from all the tested varieties, however Yalakki, kadubale, pachhabale (M. cavendishii) and Chandrabale were sensorily more acceptable. The temperature program used for processing and bottling gave sediment free juice. EXAMPLE 4 In this experiment 1 kg of ripe guava (Psidium guajava) was washed, mixed with potassium metabisulphite at the rate of 212 mg/kg of fruit and blended in a warring blender. The pulp was hydrolysed and clarified as explained under example 1. The yield of the juice was 75% of fruit and had a pH of 3.8 and 10° Brix. The filtrate was heated to 80° C cooled and filtered through cellulose pad under vacuum. The clarified juice was bottled at 70° C. The bottled juice was free from sediment. EXAMPLE 5 Experiment mentioned under example 1 was repeated using Litchi (Litchi chiensis) fruit. One kg of fruit gave 740 g of pulp, which yielded 710 ml of juice and 30 g of residue. The yield of juice was 71% of fruit and had a pH of 5.2 and was of 18° Brix. The juice was filtered and bottled as mentioned under experiment 1. The juice was free from sediment. From the above-mentioned examples it is evident that clarified juices free from sediments can be obtained from various varieties of banana, guava and litchi. The overall methodology used for hydrolysis allows rapid processing as pasteurization of the pulp and overnight hydrolysis are avoided and hydrolysis time is reduced to 3 h. Juice was heat processed, cooled to room temperature to hasten sedimentation and filtered immediately after hydrolysis. Shelf studies indicated that a storage temperature of about 10° C would prevent browning of the juice. ADVANTAGES

The main advantages of the present invention are: 1. Shortening of processing procedures used in the hydrolysis of fruit pulp, which is important for the viability of the process.

2. Shortening of the process by 5-10' h also leads to elimination of contamination which otherwise may occur during lengthy hydrolysis method.

3. In the already existing process hydrolyzed pulp is pressed through cheesecloth and the crude juice obtained is kept for cold racking for sedimentation and then filtered. In the present method the crude juice is heat processed, cooled to room temperature for completion of sedimentation and filtered immediately to obtain clarified juice in a shorter period.

4. The bottled juice is free from sediment.

Claims

We claim:

1. A process for the production of sediment free clarified fruit juice(s), which comprising the steps of: a) preparing a pulp of fruit; b) adding preservatives in the range of 0.2g -0.3g/ kg of pulp to the pulp of step (a) while the preparing a pulp process is on; c) treating the pulp obtained from step (b) with pectinolytic enzyme having an activity of 600-1200 units/kg of pulp at a temperature in the range of 30°C-40°C; d) holding the enzyme treated pulp mixture of step (c) for a period of 3-5hrs; e) filtering the above obtained hydrolysate to get a clear juice; f) optionally adding cellulase enzyme in the range of 0.05% v/v to juice obtained from step (e) for additional clarification, followed by raising of temperature in the range of 50-60° C for a period of 30-60 minutes, g) heating the enzyme treated juice obtained from steps (e) and (f) at a temperature in the range of 70-85°C for a period of 5-15 min followed by cooling the juice to a temperature in the range of 10-15°C, and h) filtering the juice under vacuum to obtain sediment free clarified fruit juice.

2. A process as claimed in claim 1 , wherein in step (a) the fruits are selected from pulp yielding fruits.

3. A process as claimed in claim 2, wherein the pulp yielding fruits are banana, litchi, and guava.

4. A process as claimed in claim 1, wherein in step (a) pulp preparation is carried out by using a blender.

5. A process as claimed in claim 4, wherein the blender is warring blender.

6. A process as claimed in claim 1, wherein in step (b) the preservatives selected from potassium metabisulphite and benzoic acid.

7. A process as claimed in claim 1, wherein in step (c) the pectinolytic enzyme is pectinex.

8. A process as claimed in claim 1, wherein in step (c) the preferred temperature is about 30°C

9. A process as claimed in claim 1, wherein in step (d) the holding time is about 3 hrs.

10. A process as claimed in claim 1, wherein in step (e) the vacuum is about 8-20 mbar.

11. A process as claimed in claim 1, wherein in step (f) the temperature is about 55°C

12. A process as claimed in claim 1, wherein the clarity of the juice measured by the optical density is 0.01-0.02.