Process of antimicrobial treatment of fresh produce, particularly mushroom

Abstract

Preservative compositions using toxicologically acceptable ingredients, and employing a pH of 9.0 or above for at least part of the process, for reducing the initial population and controlling the growth of spoilage bacteria and human pathogens and for preventing unwanted color changes in fresh and processed produce, particularly mushrooms. Aqueous solutions of preservatives are prepared and applied in multiple stages to the mushrooms, by spraying or immersion. More specifically, disclosed is a method for preserving fresh and processed mushrooms, comprising the steps of: contacting the mushrooms with an antimicrobial solution having a pH of about 9.0 or above; and rinsing the mushrooms one or more times immediately after the contacting step with pH-neutralizing solutions having a pH sufficient to return the produce to its physiological pH. In a preferred embodiment, electrolyzed basic water is used in the first stage high-pH rinse step and electrolyzed acid water is used in the second stage neutralizing solution step. Tyrosinase inhibitors such as ascorbates, erythorbates, EDTA or calcium chloride are added to the neutralizing solutions to inhibit enzymatic browning.

1 . A process for preserving fresh and processed mushrooms, comprising the step of: 
 (a) contacting the mushrooms with a first microbial solution having a pH of at least about 9.0; and    (b) rinsing the mushrooms after said antimicrobial contacting step with a pH-neutralizing solution having a pH sufficient to return the mushrooms to the mushroom physiological pH of about 6.5 comprising an acidulent selected from the soup consisting of citric acid, fumaric acid, benzoic acid and combinations thereof; and    (c) rinsing the mushrooms with a second pH-neutralizing solution comprising a browning inhibitor.    
   
   
       2 . The process of  claim 1  wherein the browning inhibitor is selected from the group consisting of ascorbate, erythorbate, EDTA and calcium chloride.  
   
   
       3 . The method of  claim 2  wherein said pH-neutralizing solution comprises 1 to 50 ppm chlorine dioxide.  
   
   
       4 . The method of  claim 3  further comprising the step of rinsing the mushrooms with a second pH-neutralizing solution comprising a browning inhibitor.  
   
   
       5 . The method of  claim 4  wherein said first pH-neutralizing solution comprises fumaric acid and sodium benzoate.  
   
   
       6 . The process of  claim 5  wherein the browning inhibitor is selected from the group consisting of ascorbate, erythorbate, EDTA and calcium chloride.  
   
   
       7 . The process of  claim 5  wherein the neutralizing solution step (c) comprises the browning inhibitor in the range of 1 to 4 percent by weight and the browning inhibitor is selected from the group consisting of ascorbate, erythorbate and a combination thereof.  
   
   
       8 . A process for preserving fresh and processed mushrooms, comprising the steps of: 
 (a) contacting the mushrooms with a first antimicrobial solution having a pH of at least about 9.0;    (b) rinsing the mushrooms after said antimicrobial contacting step with a pH-neutralizing solution comprising ozonated water.    
   
   
       9 . The process of  claim 8  further comprising the step of: 
 (c) rinsing the mushrooms with a second pH neutralizing solution comprising a browning inhibitor.    
   
   
       10 . The process of  claim 9  wherein the browning inhibitor is selected from the group consisting of ascorbate, erythorbate, EDTA and calcium chloride.  
   
   
       11 . The method of  claim 9  wherein said browning inhibitor is selected from the group consisting of ascorbate, erythorbate and a combination thereof.  
   
   
       12 . A process for preserving fresh and processed mushrooms, comprising the steps of: 
 (a) contacting the mushrooms with a first antimicrobial solution comprising ozonated water; and    (b) rinsing the mushrooms with a neutralizing solution comprising a browning inhibitor.    
   
   
       13 . The process of  claim 12  wherein the browning inhibitor is selected from the group consisting of ascorbate, erythorbate, EDTA and calcium chloride.  
   
   
       14 . The process of  claim 13  wherein the neutralizing solution of step (c) comprises the browning inhibitor in the range of 1 to 4 percent by weight and the browning inhibitor is selected from the group consisting of ascorbate, erythorbate and a combination thereof.  
   
   
       15 . The method of  claim 12  wherein said first antimicrobial solution has a pH of at least about 9.0.  
   
   
       16 . The method of  claim 15  wherein said second pH neutralizing solution comprises a browning inhibitor and chlorine dioxide.  
   
   
       17 . The method of  claim 16  wherein said second has a pH sufficient to return the mushrooms to the mushroom physiological pH of about 6.5 and further comprising a browning inhibitor and chlorine dioxide.