Low-sulphur fruit drying process

Abstract

Processes and methods for producing dried fruit which has been treated with sulphur dioxide. Such processes and methods are particularly adapted for producing golden raisins which have relatively low concentrations of sulphur dioxide. To produce golden raisins, fresh sultana grapes are subjected to sulphur dioxide fumigation before undergoing a series of washing and rinsing steps which may include a cold water bath, a hot lye bath, and cold water sprays before being placed into drying tunnels. After drying, golden raisins may be undergo an additional treatment of sulphur dioxide.

What is claimed is: 
     
         1 . A process for producing raisins, comprising:
 a) a fumigating step, said fumigating step comprising fumigating grapes with sulphur dioxide at a ratio of about 1 pound of sulphur dioxide to 1000 pounds of grapes;   b) a bathing step, said bathing step comprising bathing said grapes in a hot fluid; and   c) a dehydrating step, said dehydrating step comprising dehydrating said grapes;   wherein said bathing step is performed after said fumigating step and wherein said dehydrating step is performed after said bathing step.   
     
     
         2 . The process of  claim 1 , further comprising:
 a second bathing step, said second bathing step comprising bathing said grapes in a cold fluid,   wherein said second bathing step is performed after said fumigating step.   
     
     
         3 . The process of  claim 2 , further comprising:
 a shaking step, said shaking step comprising mechanically shaking said grapes,   wherein said shaking step is performed after said second bathing step.   
     
     
         4 . The process of  claim 1 , further comprising:
 a shaking step, said shaking step comprising mechanically shaking said grapes,   wherein said shaking step is performed after said fumigating step.   
     
     
         5 . The process of  claim 1 , further comprising:
 a shaking step, said shaking step comprising mechanically shaking said grapes,   wherein said shaking step is performed after said bathing step.   
     
     
         6 . The process of  claim 1 , further comprising:
 a spraying step, said spraying step comprising spraying said grapes with a cold fluid.   
     
     
         7 . The process of  claim 1 , wherein said fumigating step lasts for about 10 to 14 hours. 
     
     
         8 . The process of  claim 1 , wherein in said bathing step, said hot fluid has a temperature of between about 130 and about 190 degrees Fahrenheit. 
     
     
         9 . The process of  claim 1 , wherein said grapes have a sugar content of between about 17 and about 24 Brix before said bathing step. 
     
     
         10 . The process of  claim 1 , wherein said hot fluid comprises a solution of sodium hydroxide and water. 
     
     
         11 . The process of  claim 10 , wherein said solution comprises a ratio of about 1 pound of sodium hydroxide to about 47 gallons of water. 
     
     
         12 . A process for producing raisins, comprising the sequential steps of:
 a) placing grapes into a fumigation chamber and exposing said grapes to sulphur dioxide at ratio of about 1 pound of sulphur dioxide to 1000 pounds of grapes;   b) removing said grapes from said fumigation chamber and placing said grapes in cold water;   c) removing said grapes from said cold water and placing said grapes onto a first shaker;   d) removing said grapes from said first shaker and placing said grapes in a hot solution of sodium hydroxide and water;   e) removing said grapes from said hot solution and placing said grapes onto a second shaker;   f) spraying said grapes with cold water; and   g) removing said grapes from said second shaker and placing said grapes into a dehydrator.   
     
     
         13 . The process of  claim 12 , wherein said hot solution has a temperature of between about 130 and about 190 degrees Fahrenheit. 
     
     
         14 . The process of  claim 12 , wherein said hot solution comprises a ratio of about 1 pound of sodium hydroxide to about 47 gallons of water. 
     
     
         15 . The process of  claim 12 , wherein in said fumigation chamber, said grapes are exposed to sulphur dioxide for about 10 to 14 hours.