Process for hard panning of chewable cores and cores produced by the process

ABSTRACT

The invention relates to a process for the hard panning of chewable cores in a pan or drum wherein a syrup of a crystallizable sugar or polyol is intermittently sprayed over a bed of the cores and the cores are dried between sprayings with a flow of air. The speed and efficiency of the panning process is increased by controlling the drying of the cores between sprayings by controlling parameters of the drying air in such a way as to intentionally leave a substantial residual moisture in the drying coating layer at the start of a subsequent spraying phase. The chewable products are preferably xylitol coated chewing gums.

INFORMATION

DETAILED DESCRIPTION OF THE INVENTION

EXAMPLES 1 TO 6

Examples 1 to 3 were conducted on a batch size of 350 kg pellet centres, coated to a 50% weight increase. Examples 4 to 6 were conducted on a batch size 60 kg pellet centres, also coated to a 50% weight increase. The sealing syrup composition was xylitol 65%, gum arabic 7%, water 28%; the coating syrup composition was xylitol 72%, gum arabic 2%, water 26%.

The panning conditions, parameters and the process times are set out in Table 1.

The following comments pertain to each of the tests separately:

1. Batch 1600/4 Standard Process/Comparative Example

This batch followed the coating procedure used as a standard. The bed temperature was 22° C. As would be expected with a standard procedure this batch did not cause any difficulties during the processing. The batch took 292 minutes to process. This is comparable to the times obtained during previous scale-up trials for a standard batch.

On tasting the samples 2 weeks after production the pellets had a good gloss, with a smooth surface and little or no corner loss. The pellets had an acceptably crunchy coating.

2. Batch 1600/3

This trial was comparable to the standard procedure except for the raised temperature. The direction of the air flow was reverse as in the standard procedure. Some problems were noted with dusting during processing. The dust created a dusty surface on the surface of the pellets, which appeared to prevent the syrup application from drying properly.

The syrup appeared to be crystallizing rapidly giving rise to a rough surface. Due to the roughness a pause period had to be incorporated into the process. The degree of dusting in combination with the pause period caused a sticky period during the process. A number of multiples formed within the pan.

Despite the dusting the process was about 30% faster than the standard. The quality of the pellets was not as good as the standard.

3. Batch 1600/5

Direct air-flow was used in the process as opposed to the reverse air-flow utilized in the standard procedure. Direct air-flow reduces the effectiveness of the drying.

This batch followed an identical syrup dosage as applied during the standard batch. Changes were made during the processing whereby larger syrup applications could be made and drying times could be reduced significantly. Overall, this batch processed≈35% faster than the standard batch (188 minutes compared to 292 minutes for the standard). The batch also processed quicker than bath 1600/3.

The less efficient drying allowed a smoother coating to be applied and removed the need for pause periods during the process. On tasting the samples 2 weeks after production it was noted that these pellets had a smooth surface with little or no corner loss (as standard). These pellets had a good crunch, similar, if not slightly firmer, than the crunch obtained with the standard procedure.

Overall, the quality of the pellets remains as good, if not better, compared to the standard procedure. The process also offers a considerable time saving.

4. Batch 1200/4

This trial used lower initial syrup applications and a product temperature close to that desired (30° C.). The reduced syrup applications and increased product temperature appeared to resolve all of the problems previously encountered with sticking and multiple formation. In order to achieve the desired product temperature of 30° C. the drying air temperature had to be far higher at around 37° C. to 40° C.

The finished coating was very smooth and quite glossy. However, most of the pellets had well-rounded corners, a sign of abrasion during the process. The finished coating was crisp with a good crunch equal to the standard

5. Batch 1200/5

The product temperature was raised by 5° C., above that utilized for Trial 1200/4. The drying air temperature for this trial was set at a maximum of 45-48° C. for much of the process. Increasing the product temperature by 5° C. throughout this trial appeared to significantly reduce any problems associated with stickiness during the drying phases of the process, and to aid more rapid drying of the syrup coats. The more efficient drying of the syrup applications allowed total drying times to be reduced, resulting in a faster process than Trial 1200/4 (177 minutes versus 213 minutes).

The quality of the finished pellet coating did not appear to be effected by the changes in the protocol. The finished product had a slightly improved sheen over that observed for Trial 1200/4. Corner loss on the pellets was comparable between both batches. Crunchiness of the pellet coating was perhaps marginally superior to Trial 1200/4; otherwise there was little overall difference between the products.

6. Batch 1200/6

Working at this high temperature caused a number of processing difficulties with dusting and multiple formation. Despite this the finished product was very smooth although the surface finish was relatively dull. The products also exhibited significant corner loss.

The pellet crunch was not as crisp as that produced in trial 1200/4.

EXAMPLE 7

Control of Coating by Relative Humidity

A batch of chewing gum pellet centres were coated to a 50% weight increase with the same syrups as those used in Examples 1-6. The initial layers were produced with an inlet air temperature of about 30° C. whereafter the inlet air temperature was raised to 40° C. for the actual coating. The change in relative humidity (RH) of the outlet air was monitored at the increased temperature phase.

The relative humidity of the outlet air had a basic level of about 12% measured as the RH of the air in the outlet tube during the pause, during which the bed was by-passed. The RH of the outlet air was found to increase rapidly during the first 30 seconds of the drying, whereafter it decreased slowly as indicated in Table 2.

The next spraying cycle started well before the RH had reached the basic value of about 12%

The drying sequence was between 2 and 3 minutes and the Table shows that some moisture that could have been dried off from the layer was intentionally left in the layer. By this control procedure the process could be speeded up considerably while ascertaining that the layer did not over-dry to a point where dusting would disturb the coating surface.

EXAMPLE 8

Control of Coating by Relative Humidity

Two batches of chewing gum pellets (10 kg) were coated in a Driacoater 500/600 Vario equipment with a syrup containing 65% xylitol and 7% gum arabic in the sealing syrup and 72% xylitol and 2% gum arabic in the coating syrup.

The outlet air RH was monitored during the process. The basic level for the RH of the outlet air was determined as the RH of the outlet air at the point at which the pellets were observed to be fully dried, and at which the RH of the air appeared to have reached a plateau.

The trigger point for the next -syrup application was set at a point when the desired difference between the observed RH of the outlet air and the predetermined basic RH level was reached, i.e. a point 1-10% RH above the basic level RH of the outlet air. For example, if the basic level RH of the outlet air was 30%, and the desired difference in RH was 5%, then when the next syrup application would be applied when the measured RH of the outlet air reached 35%.

The temperature of the drying air was raised after the sealing phase from 30° C. to 50° C. The change to RH control was made during phase 4 onwards. The RH of the outlet air was used to trigger syrup application when the RH was above its basic level.

Batch A set a target of applying the next syrup phase when the RH of the outlet air was −5% higher than the basic levels assessed in a previous trial with complete drying.

The batch progressed well with the addition of up to 5% RH to the basic level. During this batch the relative humidity of the inlet feed air was relatively high as the dew point in the air drier was monitored at −3° CTP. The batch was completed 32 minutes quicker than a standard trial.

Batch B intended to add 6+% to the basic level RH of the outlet air. The RH of the inlet air had changed to the dryer conditions of a dew point of −10° CTP. The RH of the outlet air dropped very rapidly in this batch. The coating time for the process was an improvement over the previous trial and coating times were reduced significantly compared to standard trials.

The target in Batch B was to apply the next syrup phase 6% higher. However, the test showed that this level could potentially be increased as the RH of the outlet air was dropping very rapidly. This indicated that with a lower RH of the inlet air the trigger point could be increased without having a detrimental effect on the coating quality.

CLAIMS

1. A process for the production of chewable coated cores comprising the hard panning of chewable cores in a coating pan or drum wherein a syrup containing at least one of a crystallizable polyol, a crystallizable sugar or mixtures thereof is intermittently sprayed over a rotating bed of the cores and said cores are dried between sprayings with a flow of air, said cores being dried between sprayings by controlling effective parameters of said drying air selected from the group consisting of air humidity, air temperature, air flow speed, air flow time, air flow direction and any combination thereof and stopping said drying before the relative humidity of the outlet flow of drying air has reached its basic level at which its gradient has flattened to a plateau, so as to cause a substantial residual moisture to remain in the drying coating layer at the start of a subsequent spraying phase.

2. A process according to claim 1, wherein said parameters comprise the relative humidity of said drying air at an outlet of said pan or drum.

3. A process according to claim 1 or 2, wherein said parameters comprise the temperature of said drying air at an inlet of said pan or drum.

4. A process according to claim 2, wherein the relative humidity of the outlet air when starting said subsequent spraying is higher than the basic relative humidity level.

5. A process according to claim 1, wherein a number of coating cycles is performed, each coating cycle comprises a syrup application phase, an optional pause phase and a drying phase.

6. A process according to claim 2, wherein the flow of drying air to said bed is stopped before the drying is completed and the relative humidity of the outlet air is 1-10 percentages higher than its basic level.

7. A process according to claim 5, wherein the direction of the air during at least a part of said drying phases is direct with the air flowing from above the bed through the product.

8. A process according to claim 1, wherein the coating syrup contains about 40 to 80% of the total weight of a polyol selected from the group consisting of xylitol, sorbitol, maltitol, isomalt and mixtures thereof.

9. A process according to claim 8, wherein the polyol is xylitol.

10. A process according to claim 9, wherein the temperature of the bed of chewable cores is adjusted to a temperature of 25 to 45° C. for at least a part of the total coating procedure, and the drying during said part of the procedure is performed with air having an inlet temperature of 25 to 75° C.

11. A process according to claim 10, wherein the bed temperature is 33 to 40° C.

12. A process according to claim 10, wherein the inlet temperature is 40 to 50° C.

13. A process according to claim 10, wherein the coating syrup temperature is 40 to 80° C.

14. A process according to claim 1, wherein the coating syrup contains about 40 to 80% of the total weight of a sugar selected from the group consisting of saccharose, fructose and glucose.

15. A process according to claim 1, wherein the coating syrup contains 1 to 20% of gum of the total weight.

16. A process according to claim 8, wherein the coating syrup comprises other polyols, flavors, pigments, special sweeteners, insoluble additives or mixtures thereof.

17. A process according to claim 1, wherein the coating syrup contains dissolved, suspended or dissolved and suspended xylitol, sorbitol, lacitol maltitol, isomalt, mannitol or mixtures thereof.

18. A process according to claim 1, wherein the coating of the chewable cores is started by an initial sequence having a bed temperature lower than the bed temperature during the residual moisture retaining drying procedure.

19. A process according to claim 1, wherein the coating of the chewable cores is finished by an end coating sequence having a bed temperature lower than the bed temperature during said residual moisture retaining drying procedure.

20. A process according to claim 18 or 19, wherein the direction of the flow of air during the initial coating, the end coating or both coatings is reversed such that the air flows from below the bed through the product.

21. A process according to claim 1, wherein the direction of the air flow, the air flow speed, the air flow time, the temperature of the air or any combination thereof is changed during the coating procedure.

22. A process according to claim 1, wherein the cores are coated with syrup until a desired coating thickness is provided and the coated cores are tempered after the coating for a time sufficient to allow crystallization of the polyol or sugar in said coating to provide a crunchy hard coating.

23. A process according to claim 1, wherein said core comprises chewing gum.

24. A process according to claim 6, wherein the relative humidity of the outlet air is more than 3 percentages higher than its basic level.

25. A process according to claim 6, wherein the relative humidity of the outlet air is 4-8 percentages higher than its basic level.

26. A process according to claim 10, wherein the temperature of the bed is adjusted to a temperature of from 30 to 40° C. and said inlet temperature is from 30 to 65° C.

27. A process according to claim 15 wherein the gum is Gum Arabic.

28. A process for the production of chewable coated cores by hard panning comprising: spraying a syrup containing at least one of a crystallizable polyol, a crystallizable sugar and combinations thereof over a rotating bed of chewable cores in a coating pan or drum; stopping said spraying of said rotating cores while continuing rotation; starting to dry said cores with an inlet flow of air; controlling the drying of said rotating cores by controlling effective parameters of the drying air selected from the group consisting of air humidity, air temperature, air flow speed, air flow time, air flow direction and any combination thereof; stopping said flow of drying air at a point before the relative humidity of the outlet flow of said drying air has reached its basic level at which its gradient has flattened to a plateau indicating that a substantial residual moisture remains in the drying coating layer; starting a subsequent spraying phase by spraying said syrup onto the moisture containing layer of the previous spraying phase; and repeating the spraying and drying of said rotating cores until a predetermined coating has been provided.

COPYRIGHT

User acknowledges that Fairview Research and its third party providers retain all right, title and interest in and to this xml under applicable copyright laws. User acquires no ownership rights to this xml including but not limited to its format. User hereby accepts the terms and conditions of the License Agreement.