Barley for production of flavor-stable beverage

Abstract

According to the invention, there is provided null-LOX-1 barley and plant products produced thereof, such as malt manufactured by using barley kernels defective in synthesis of the fatty acid-converting enzyme lipoxygenase-1. Said enzyme accounts for the principal activity related to conversion of linoleic acid into 9-hydroperoxy octadecadienoic acid, a lipoxygenase pathway metabolite, which-through further enzymatic or spontaneous reactions-may lead to the appearance of trans-2-nonenal. The invention enables brewers to produce a beer devoid of detectable trans-2-nonenal-specific off flavors, even after prolonged storage of the beverage.

We claim: 
     
         1 . A barley plant, or a part thereof, wherein said plant or part thereof comprises less than 1% of the LOX-1 protein activity compared to a wild-type barley plant. 
     
     
         2 . The barley plant, or a part thereof, according to  claim 1 , wherein the gene encoding LOX-1 of said plant comprises a premature nonsense codon. 
     
     
         3 . The barley plant, or a part thereof, according to  claim 1 , wherein the gene encoding LOX-1 of said plant comprises at least one mutation within a splice site. 
     
     
         4 . The plant product according to  claim 15 , wherein the plant product is a malt composition comprising a processed barley plant or part thereof, wherein said barley plant is the barley plant comprises less than 1% LOX-1 protein compared to a wild-type barley plant. 
     
     
         5 . The plant product according to  claim 15 , wherein the plant product is a wort composition prepared using the barley plant or part thereof comprising less than 1% LOX-1 protein compared to a wild-type barley plant. 
     
     
         6 . The plant product according to  claim 5 , wherein the plant product is a wort composition, and wherein said composition is prepared using an enzyme composition or an enzyme mixture composition. 
     
     
         7 . The plant product according to  claim 15 , wherein the plant product is a beverage having stable organoleptic qualities, wherein said beverage is obtained by manufacturing the barley plant or part thereof comprising less than 1% LOX-1 protein compared to a wild-type barley plant. 
     
     
         8 . The plant product according to  claim 7 , wherein the plant product is a beverage, and wherein said beverage is beer. 
     
     
         9 . The plant product according to  claim 7 , wherein the plant product is a beverage, and wherein said beverage is prepared using malt prepared from kernels of said barley plant. 
     
     
         10 . The plant product according to  claim 7 , wherein the plant product is a beverage, and wherein said beverage is prepared from a wort composition prepared from a barley plant or part thereof, or from a malt composition prepared from said barley plant or part thereof, wherein said barley plant comprises less than 1% of the LOX-1 activity of a wild-type barley plant. 
     
     
         11 . The plant product according to  claim 7 , wherein the plant product is a beverage and wherein said beverage is prepared from unmalted barley plants or parts thereof. 
     
     
         12 . The plant product according to  claim 7 , wherein the plant product is a beverage, and wherein said beverage is a non-fermented beverage. 
     
     
         13 . The plant product according to  claim 7 , wherein the plant product is a beverage, and wherein the ratio of 9,12,13-trihydroxyoctadecenoic acid to 9,10,13-trihydroxyoctadecenoic acid within said beverage is at the most 1.8. 
     
     
         14 . The plant product according to  claim 13 , wherein the plant product is a beverage, and wherein said beverage comprises at the most 0.05 ppb free trans-2-nonenal (T2N) after incubation at 37° C. for 4 weeks, in the presence of in the range of 4 to 6 ppm sulfite. 
     
     
         15 . A plant product produced from the barley plant, or a part thereof, according to  claim 1 . 
     
     
         16 . The plant product according to  claim 15 , wherein the plant product is a food composition, a feed composition, or a fragrance raw material composition comprising the barley plant or part thereof comprising less than 1% LOX-1 protein compared to a wild-type barley plant. 
     
     
         17 . A method of producing a beverage having stable organoleptic qualities, said method comprising the steps of:
 (i) preparing a composition comprising a barley plant or parts thereof according to  claim 4 ;   (ii) processing the composition of (i) into a beverage;   thereby obtaining a beverage with stable organoleptic qualities.   
     
     
         18 . The method according to  claim 17 , wherein step (i) comprises preparing a malt composition from kernels of said barley plant or part thereof. 
     
     
         19 . The method according to  claim 17 , wherein the method further comprises a step of incubation with a LOX inhibitor. 
     
     
         20 . The method according to  claim 17 , wherein processing the composition into a beverages comprises a mashing step.