Process and equipment

Abstract

Problems with incipiently gelling alginate or low-methoxy pectate sols in a bath of an aqueous solution containing calcium ions are reduced by having in the bath a perforated support surface which can be oscillated. The surface is preferably oscillated horizontally and vertically and preferably these oscillations are synchronised. Transport means to remove the product from the bath can be provided at one end of the bath. It is advantageous to ensure that at the beginning of the vertical oscillation the horizontal oscillation is in the direction of such transport means. Portions of the sol can be formed by extrusion either below or above the surface of the bath. The process is particularly useful for sols which have a sugar content greater than 10%. The invention also provides equipment comprising such a perforated support surface. Although the equipment is particularly useful for preparing alginate and low-methoxy pectate products it can also be used advantageously for other products which are formed in a bath and are susceptible to damage before they solidify adequately.

1 . A process comprising: treating portions of an aqueous alginate sol or an aqueous low-methoxy pectate sol with an aqueous solution containing dissolved calcium ions in a bath so that the calcium ions diffuse into the sol thereby gelling the sol to form portions of alginate or low-methoxy pectate gel in which the aqueous solution containing dissolved calcium ions has a lower density than the density of the sol wherein the bath contains an oscillated perforated support surface effective to catch descending incipiently-gelling portions of the aqueous alginate sol or the aqueous low-methoxy pectate sol.  
     
     
         2 . A process according to  claim 1  in which the aqueous alginate sol or aqueous low-methoxy pectate sol has a density at least 0.002 g/ml greater than the density of the aqueous solution containing dissolved calcium ions.  
     
     
         3 . A process according to  claim 2  in which the density of the aqueous alginate sol or the aqueous low-methoxy pectate sol is at least 1.3 g/ml.  
     
     
         4 . A process according to  claim 1  in which the support surface is oscillated vertically.  
     
     
         5 . A process according to  claim 4  in which the support surface is also oscillated horizontally.  
     
     
         6 . A process according to  claim 5  in which the vertical and horizontal oscillations of the support surface are synchronised.  
     
     
         7 . A process according to  claim 6  in which the incipiently gelling portions of the aqueous alginate sol or the aqueous low-methoxy pectate are removed from the bath by transport means provided at one end of the support surface.  
     
     
         8 . A process according to  claim 7  in which when each vertical oscillation begins horizontal oscillation is in the direction of the transport means.  
     
     
         9 . A process according to  claim 8  in which the end of the support surface furthest from the transport means oscillates vertically over a shorter distance than the end of the support surface nearest the transport means.  
     
     
         10 . A process according to  claim 9  in which the vertical oscillation of the support surface is synchronized so that the end of the support surface nearest the transport means reaches its lowest point just after the end of the support surface furthest from the transport means reaches its lowest point.  
     
     
         11 . A process according to  claim 10  in which the vertical oscillation of the support surface is synchronised so that the support surface is horizontal when lowest.  
     
     
         12 . A process according to  claim 1  in which the support surface is never less than 5 cms below the surface in the bath of the aqueous solution containing dissolved calcium ions.  
     
     
         13 . A process according to  claim 12  in which the support surface is not more than 30 cms below the surface in the bath of the aqueous solution containing dissolved calcium ions.  
     
     
         14 . A process according to  claim 13  in which the support surface is not more than 20 cms below the surface in the bath of the aqueous solution containing dissolved calcium ions.  
     
     
         15 . A process according to  claim 1  in which the portions of the aqueous alginate sol or aqueous low-methoxy pectate sol are formed by extrusion through a nozzle below the surface in the bath of the aqueous solution containing dissolved calcium ions.  
     
     
         16 . A process according to  claim 15  in which the nozzle is not more than 5 cms below the surface in the bath of the aqueous solution containing dissolved calcium ions.  
     
     
         17 . A process according to  claim 1  in which the calcium ions are provided from calcium lactate.  
     
     
         18 . A process according to  claim 1  in which the aqueous alginate sol or the low-methoxy pectate sol contains dispersed fruit puree.  
     
     
         19 . A process according to  claim 18  in which in the aqueous alginate sol or the low-methoxy pectate sol there is more than 10% of sugar.  
     
     
         20 . A process according to  claim 19  in which in the sugar fructose predominates.  
     
     
         21 . A process according to  claim 20  in which fructose is the only added sugar.  
     
     
         22 . A process according to claim in which the sol is an aqueous alginate sol.  
     
     
         23 . A process according to  claim 1  further comprising storing the incipiently-gelling portions of the aqueous alginate sol or the aqueous low-methoxy pectate sol after the portions have been removed from the bath in a support matrix having a balanced density to ensure the incipiently-gelling portions are not deformed while firming up by diffusion of calcium into the portions.  
     
     
         24 . A continuous process according to  claim 1 .  
     
     
         25 . A gelled product based on an alginate gel or low-methoxy pectate gel formed according to  claim 1 .  
     
     
         26 . A system suitable for use in preparing products which are formed in a bath and are susceptible to damage before the products solidify adequately, comprising a bath, a perforated support surface in the bath for the products and an oscillating assembly adapted and structured to oscillate the support surface.  
     
     
         27 . The system according to  claim 26  further comprising an extrusion nozzle positioned to deliver the products to the bath.  
     
     
         28 . The system according to  claim 26  in which the oscillating assembly is structured to be able to oscillate the support surface at least vertically.  
     
     
         29 . The system according to  claim 28  in which the oscillating assembly is structured to be able to oscillate the support surface vertically and horizontally.  
     
     
         30 . The system according to  claim 29  further comprising a transport assembly provided at one end of the support surface and structured to remove the products from the bath.  
     
     
         31 . The system according to  claim 30  in which the oscillating assembly is structured such that when each vertical oscillation begins horizontal oscillation is towards the transport assembly.  
     
     
         32 . The system according to  claim 31  in which the oscillating assembly is structured such that the end of the support surface furthest from the transport assembly oscillates vertically over a shorter distance than the end of the support surface nearest the transport assembly.  
     
     
         33 . The system according to  claim 32  in which the oscillating assembly is structured such that vertical oscillation of the support surface is synchronized so that the end of the support surface nearest the transport assembly reaches its lowest point just after the end of the support surface furthest from the transport assembly reaches its lowest point.  
     
     
         34 . The system according to  claim 30  in which the oscillating assembly is structured such that the support surface is horizontal when lowest.  
     
     
         35 . The system according to  claim 27  in which the bath includes an input for a solution containing dissolved calcium ions and an outlet for the solution determining the level of the solution when the solution is in the bath.  
     
     
         36 . The system according to  claim 35  in which the oscillating assembly is structured such that the support surface is never less than 5 cms below the level of the solution when the solution is in the bath.  
     
     
         37 . The system according to  claim 35  in which the oscillating assembly is structured such that the support surface is never more than 30 cms below the level of the solution when the solution is in the bath.  
     
     
         38 . The system according to  claim 37  in which the oscillating assembly is structured such that the support surface is never more than 20 cms below the level of the solution when the solution is in the bath.  
     
     
         39 . The system according to  claim 35  in which the extrusion nozzle is below the level of the solution when the solution is in the bath.  
     
     
         40 . The system according to  claim 39  in which the extrusion nozzle is not more than 5 cms below the level of the solution when the solution is in the bath.  
     
     
         41 . The system according to  claim 40  in which the oscillating assembly is structured such that the support surface is never less than 5 cms below the extrusion nozzle.  
     
     
         42 . (canceled)  
     
     
         43 . (canceled)