Enhancement of cocoa quality and flavor by using pichia kluyveri yeast starter culture for cocoa fermentation

Abstract

Described are Pichia kluyveri yeast strains with advantageous properties useful in cacao fermentation processes, and related methods and products, including fermented cocoa beans having a ratio of isobutyl acetate/isobutanol higher than 1 and/or a ratio of isoamyl acetate/isoamyl alcohol higher than 0.005, and cocoa-based products prepared therefrom, as well as methods for the fermentation of cocoa beans comprising using at least one Pichia kluyveri yeast strain, fermented cocoa beans obtainable thereby, and cocoa-based products prepared therefrom and obtainable thereby.

1 . Fermented cocoa beans having a ratio of isobutyl acetate/isobutanol higher than 1 and/or a ratio of isoamyl acetate/isoamyl alcohol higher than 0.005. 
     
     
         2 . Fermented cocoa beans according to  claim 1 , wherein the fermented cocoa beans are of the variety Forastero. 
     
     
         3 . A cocoa-based product having an improved flavor profile, wherein the cocoa-based product is prepared from the fermented cocoa beans according to  claim 1 . 
     
     
         4 . A method for the fermentation of cocoa beans comprising the steps of:
 a) adding to a plant material essentially consisting of beans and/or pulp derived from fruit pods of the species  Theobroma cacao  at least one  Pichia kluyveri  yeast strain;   b) fermenting the plant material to obtain fermented cocoa beans.   
     
     
         5 . The method according to  claim 4  further comprising the step of:
 c) drying the fermented cocoa beans. 
 
     
     
         6 . The method according to  claim 4 , wherein the  Pichia kluyveri  strain is selected from the group consisting of  Pichia kluyveri  PK-KR1 and  Pichia kluyveri  PK-KR2 as deposited on 24 Aug. 2006 at the National Measurement Institute, 541-65 Clarke Street, South Melbourne, Victoria 3205, Australia, by University of Auckland, School of Biological Sciences, Auckland 1142, New Zealand, under accession numbers V06/022711 and V06/022712, respectively, and mutant and variant strains thereof, wherein the mutant and variant strains thereof has retained or further improved the flavoring properties of V06/022711 and V06/022712, respectively. 
     
     
         7 . The method according to  claim 4 , wherein step a) is carried out at the start of fermentation. 
     
     
         8 . The method according to  claim 4 , wherein the plant material is fermented with the at least one  Pichia kluyveri  strain for at least 12 hours. 
     
     
         9 . The method according to  claim 4  further comprising adding to the plant material at least one lactic acid bacterial strain. 
     
     
         10 . The method according to  claim 9 , wherein the at least one lactic acid bacterial strain is a  Lactobacillus plantarum  bacterial strain. 
     
     
         11 . The method according to  claim 9 , wherein the at least one lactic acid bacterial strain is a  Lactobacillus paracasei  bacterial strain. 
     
     
         12 . Fermented cocoa beans obtainable by the method according to  claim 4 . 
     
     
         13 . A method of preparing a cocoa-based product comprising providing fermented cocoa beans obtainable by the method according to  claim 4  and preparing thereof a cocoa-based product. 
     
     
         14 . A cocoa-based product obtainable by the method according to  claim 13 . 
     
     
         15 . A  Pichia kluyveri  yeast strain for use in fermentation of cocoa beans and/or pulp to enhance the flavor and/or the quality of the fermented beans. 
     
     
         16 . A method of preparing a cocoa-based product comprising providing fermented cocoa beans according to  claim 1  and preparing thereof a cocoa-based product. 
     
     
         17 . A cocoa-based product obtainable by the method according to  claim 16 .