Abstract:
The disclosure relates to a coffee composition, in particular, an instant coffee composition which can provide a three-layered coffee drink in one step. The coffee composition having coffee, a foaming agent, a protein source and at least 1.3 wt % (based on the total weight of the composition) of a kappa-carrageenan, iota-carrageenan or mixture thereof. The disclosure also relates to a method for the preparation of such a composition and such a drink.

Description:
The disclosure herein relates to a coffee composition, in particular, an instant coffee composition which can provide a three-layered coffee drink in one step. It also relates to a method for the preparation of such a composition and such a drink. 
     BACKGROUND 
     Instant coffee compositions are well known. A coffee composition can be made into a coffee drink simply by the addition of hot water. For ease of use by a consumer, a coffee composition may include a creamer in order to provide a whitening effect. Both non-foaming and foaming creamers are known. 
     Known instant coffee compositions intended for use by a domestic consumer provide either a homogenous coffee drink or a two-layered drink. A composition comprising instant coffee and a foaming creamer will provide a two-layered drink consisting of a liquid layer of the main coffee drink and a foam layer. Three-layered coffee drinks are available in an “away from home” format prepared by trained staff. Such coffee drinks require considerable skill in pouring parts of the beverage without causing mixing of the layers. If it were possible to prepare such compositions conveniently at home, cooking appliances would be necessary, for example to prepare a milk foam separately. 
     Latte Macchiato type beverages with different layers can be prepared using specially designed dispensing units such as those described in U.S. Pat. No. 6,799,613 which regulate flow rate, or liquid concentrates with special dispensing machines as described in U.S. Pat. No. 7,013,933. In both cases the separation between the layers relies specifically on the difference in densities of the liquids to create two or more layers which are limited to the factors such as regulation of the flow rate and order at which the liquid components are introduced. Beverages obtained by either of these processes require more than one preparation step and may therefore be off-putting and too complicated for a consumer. 
     SUMMARY 
     There is provided herein an instant coffee composition in a convenient form for the preparation of three layered beverages which requires no skill or limited skill and no special cooking appliances, but rather a simple addition of water in a single, simple step. 
     There is provided a coffee composition comprising: 
     a) coffee; 
     b) a foaming agent; 
     c) a protein source; and 
     d) at least 1.3 wt %, based on the total weight of the composition, of a kappa-carrageenan, iota-carrageenan or mixture thereof. 
     There is also provided a method for preparing a composition as defined above which comprises mixing together the coffee, creamer and kappa-carrageenan, iota-carrageenan or mixture thereof. 
     There is additionally provided herein a method for preparing a three-layered instant coffee drink which comprises mixing hot water with a composition as defined above. 
     It has surprisingly been found that incorporation of particular carrageenans, namely kappa-carrageenan, iota-carrageenan or a mixture thereof, in a coffee composition comprising instant coffee and a foaming creamer will provide a three-layered drink on simple dilution with hot water, optionally, but preferably, with stirring. The drink contains a bottom liquid layer, a top froth layer and a middle weak gel layer. The middle layer has a density between the densities of the foam and bottom layers. This effect is not achieved with other carrageenans such as lambda-carrageenan or with other thickeners such as alginates, other gums such as xanthan gum, pectin or other functional ingredients such as microparticulated whey proteins. It is postulated, although we are not bound by this theory, that the middle gel layer is formed by the interaction of the kappa- or iota-carrageenan with the protein contained in dairy creamers, in particular caseins, and the mineral salts such as calcium and potassium salts associated with them. 
    
    
     DETAILED DESCRIPTION 
     The first component of the composition provided herein is a coffee. Instant and roast and ground coffees are well known to those skilled in the art. The composition preferably comprises an instant coffee, a roast and ground coffee or a mixture thereof in an amount of from 0.5 to 25 wt %, more preferably 5 to 20 wt %, more specifically 10 to 15 wt %, most preferably in an amount of about 12 wt %, based on the total weight of the composition. 
     The second component is a foaming agent. Again, such components are well known to those skilled in the art. A foaming agent may be a foam boosting agent containing encapsulated pressurised gas as described in EP-A-1627572 or US-A-2006-0040023. Other examples of foam boosting agents are described, for example, in U.S. Pat. No. 6,168,819, U.S. Pat. No. 5,780,092, in U.S. Pat. No. 6,048,567,U.S. Pat. No. 6,129,943 and U.S. Pat. No. 6,277,429. The foam boosting agent, preferably a carbohydrate foam boosting agent, containing encapsulated pressurised gas is preferably present in an amount of from 1-20 wt %; more preferably 5-15 wt %; and most preferably 13 wt %. 
     Foaming agent and coffee can be combined using a foaming soluble coffee as described in US 20020040038A1 (EP1627568A1) in an amount of 0.5 to 25 wt %, more preferably 5 to 20 wt %, more specifically 10 to 15 wt %, most preferably in an amount of about 12 wt %, based on the total weight of the composition. 
     The third component is a protein source. The protein source is preferably a creamer such as a dairy creamer or a non-dairy creamer and a milk protein such as casein. 
     The foaming agent and protein source may be two separate components, or may be combined, such as a foaming creamer as well known in the art. The protein source is preferably present in an amount of from 1 to 20 wt %, more preferably 5 to 15 wt % and most preferably about 12.5 wt % based on the total weight of the composition. 
     The fourth component of the composition provided herein is at least 1.3 wt %, based on the total weight of the composition, of a kappa-carrageenan, iota-carrageenan or mixture thereof. Preferably, the kappa-carrageenan, iota-carrageenan or mixture thereof is present in an amount of at least 2 wt %, more preferably at least 4 wt %, more preferably from 4 to 10 wt %, even more preferably from 5 to 7 wt % and most preferably about 6 wt %. 
     It is possible to include further components acting as a source of potassium or calcium ions, for example potassium or calcium salts such as calcium carbonate, potassium carbonate, calcium gluconate or potassium gluconate. 
     The composition provided herein may, if desired, comprise further components. For example, the composition may comprise further carrageenan fractions, other carbohydrates such as sucrose or lactose or a mixture thereof, flavourings, for example chocolate, cream, milk, caramel or coffee, and/or colourants, chocolate pieces or vitamins. 
     Compositions are further described in the following Examples. 
     EXAMPLES 
     Comparative Example 1 
     A conventional instant cappuccino reference mix was prepared by mixing together the following components: 
     
       
         
               
               
             
           
               
                   
               
             
             
               
                 1.78 g 
                 Spray dried instant soluble coffee 
               
               
                 2.22 g 
                 Sugar 
               
               
                 1.63 g 
                 Lactose 
               
               
                 7.06 g 
                 Foaming dairy creamer containing 25.0% fat 
               
               
                   
                 and 12.6% casein. 
               
               
                 2.06 g 
                 Carbohydrate foam boosting agent containing 
               
               
                   
                 encapsulated pressurised gas. 
               
               
                 0.06 g 
                 Spray dried cream flavour. 
               
               
                 14.80 g  
                 Total 
               
               
                   
               
             
          
         
       
     
     The above composition was reconstituted with 150 ml hot (88° C. water) in a 400 ml beaker having an inner diameter of 65 mm. A creamy cappuccino was obtained with a 42 mm liquid layer and a 22 mm froth layer. 
     Example 2 
     The composition of Comparative Example 1 was prepared with the addition of 1 g of the commercial carrageenan Genulacta LP41, which consists of a mixture of kappa- and iota-carrageenans. This was added to the dry reference mixture prior to reconstitution. The composition was reconstituted to obtain a cappuccino drink in the same manner as in Comparative Example 1 with stirring for about 8 to 10 seconds until the powder had been completely dissolved. 
     Within 30 seconds of stirring a beverage with three distinct layers was formed. The bottom liquid layer had a height of 35 mm, the froth layer had a height of 22 mm and a middle layer of a weak gel was formed having a height of 10 mm. The middle layer was found to be darker than the froth layer and lighter than the liquid layer. On drinking the middle layer provided a more viscous and more lubricious mouth feel than the liquid layer. It was also found to be denser and more viscous than the froth layer. The overall beverage had a thick texture with a more lubricious and creamier mouth feel as compared to the beverage prepared in Comparative Example 1. 
     Example 3 
     The composition of Example 2 was prepared with the addition of 0.08 g of spray dried artificial coffee flavour. On reconstitution a three layered cappuccino beverage was obtained. On tasting, each beverage layer had a different intensity of coffee flavour with the liquid layer having the strongest flavour. The middle layer had a pleasant coffee flavour and the foam had very little coffee flavour. 
     Example 4 
     The composition of Example 2 was prepared with the addition of 0.05 g spray dried natural milk flavour. On reconstitution a cappuccino beverage with three layers was obtained. On tasting each beverage layer had a different intensity of milk flavour. The liquid layer had the strongest milky flavour, the middle layer had a weaker but pleasantly milky flavour and the foam had very slight milk flavour. 
     Example 5 
     The composition of Comparative Example 1 was prepared with the addition of 0.5 g ISP RCIC 550 iota-carrageenan. On reconstitution three distinct layers were formed; a 33 mm liquid layer, an 8 mm middle layer and an 18 mm foam layer. 
     Example 6 
     The composition of Example 2 was prepared except that the foaming dairy creamer was replaced with an equal weight of non-foaming non-dairy creamer comprising 4.5% casein. On reconstitution the beverage had three distinct layers, a dark bottom liquid layer, a 6 mm high small middle layer and a 17 mm high foam layer. The reduced casein in the mix resulted in a reduced height of the middle layer. 
     Comparative Example 7 
     The composition of Comparative Example 1 was prepared with the addition of 1 g of commercial lambda-carrageenan, Genuvisco CSM-2. On reconstitution a cappuccino beverage with a foam and a liquid layer was obtained. Although the resulting beverage was more viscous, no third layer was formed. 
     Comparative Example 8 
     The composition of Comparative Example 1 was prepared with the addition of 1 g of commercial microparticulated whey protein Simplesse 100. On reconstitution the beverage had only two distinct layers of a foam and a liquid. 
     Comparative Example 9 
     The composition of Example 2 was prepared except that the foaming dairy creamer was replaced with an equal weight of non-foaming, non-dairy creamer containing 4.5% sodium caseinate and the carbohydrate foam boosting agent containing encapsulated pressurized gas was totally excluded. On reconstitution the beverage had no foam and no middle layer. Although gelling had occurred, it did not form a layer due to the absence of the foam. 
     Example 10 
     The composition of Example 2 was prepared except that the carbohydrate foam boosting agent was replaced with 0.3 g of edible acid (e.g. citric acid) and 0.3 g of bi-carbonate of soda. On reconstitution the beverage had three distinct layers, a dark bottom liquid layer, a 10 mm high middle layer and a 40 mm high foam layer. 
     Example 11 
     The composition of Example 2 was prepared with the addition of 1 g of Roast and Ground coffee. On reconstitution the beverage had three distinct layers with dark bottom layer, 15 foam and 10 middle gel layer. 
     Example 12 
     The composition of example 2 was prepared except that spray dried instant soluble coffee was replaced with equal amounts of roast and ground coffee. On reconstitution the beverage had three distinct layers with dark bottom layer, 20 mm foam and 10 middle gel layer. 
     Comparative Example 13 
     The composition of Comparative Example 1 was prepared with the addition of 0.15 g of the commercial carrageenan Genulacta LP41, which consists of a mixture of kappa- and iota-carrageenans, prior to reconstitution. On reconstitution a cappuccino beverage with only two layers (foam and liquid) was obtained.