hence , in a first aspect , the present invention relates to a lactate powder having a lactate content of at least 20 wt . % and a water content of less than 3 . 5 wt . %, said powder comprising cationic calcium and cationic sodium , wherein cationic calcium and cationic sodium are present in a total amount in excess of 50 % of the stoichiometric amount with regard to lactate , and wherein said calcium and sodium are contained in the powder in a molar ratio within the range of 0 . 1 - 5 . the lactate content of a material , unless indicated otherwise , refers to the amount of lactate salt that is contained in the material , including anhydrous lactate salts ( e . g . calcium lactate and sodium lactate ) and lactate salt hydrates ( e . g . calcium lactate pentahydrate ). the term “ calcium lactate ” as used herein , unless indicated otherwise , refers to anhydrous calcium lactate as well as calcium lactate hydrates . whenever reference is made herein to the water content of a material , this includes both free and bound water . crystal water that is contained in hydrates is an example of bound water . the term “ powder ” as used herein refers to a particulate material with a volume weighted average diameter ( d [ 4 , 3 ]) in the range of 5 - 2000 μm . the term “ stoichiometric quantity with regard to lactate ” as used herein to quantify the calcium and sodium cations in the powder , means the amount necessary to provide counterions for all lactate ions present in the powder . hence , an amount of 50 % of the stoichiometric amount refers to an amount providing counterions for 50 % of the lactate ions in the powder . as will be understood by those skilled in the art , the stoichiometric amount of lactate and monovalent sodium cations equates to a 1 : 1 molar ratio of lactate and sodium ions , while the stoichiometric amount of lactate and divalent calcium cations will equate to a 2 : 1 molar ratio . this means that a powder of the invention comprising a 2 : 1 mixture of calcium and sodium cations ( on the basis of mol amounts ) in a stoichiometric amount with regard to lactate will comprise lactate , ca 2 + and na + in a molar ratio of 5 : 2 : 1 , as will be understood by those skilled in the art , equating to a weight ratio of approximately 22 : 4 : 1 . in a preferred embodiment of the invention , the cationic calcium and cationic sodium are present in quantities in excess of 60 % of the stoichiometric amount with regard to lactate , preferably in excess of 70 % of said stoichiometric amount , in excess of 80 % of the said stoichiometric amount , in excess of 90 % of said stoichiometric amount , in excess of 95 % of said stoichiometric amount , in excess of 97 % of said stoichiometric amount , in excess of 98 % of said stoichiometric amount or in excess of 99 % of said stoichiometric amount . in a particularly preferred embodiment , the powder of the present invention contains a stoichiometric mixture of lactate anion and metal cations , more preferably a stoichiometric mixture of lactate anion and metal cations selected from ca 2 + and na + . the lactate powders of the present invention , despite the fact that they contain high levels of anhydrous calcium lactate can easily be dissolved in water . typically , the present powder has a dissolution time of less than 90 s ., more preferably of less than 60 s . and most preferably of less than 30 s ., when 2 g of the powder is combined with 198 ml water at ambient temperature ( 20 ° c . ), ambient pressure , and under stirring . dissolution time is determined by measuring the conductivity of the liquid . “ dissolution time ” is defined as the time to reach 95 % of the maximum conductivity under these conditions . since the total water content of the present lactate powder is less than 3 . 5 wt . %, the bulk of lactate salt contained in the powder is in anhydrous form . according to a particularly preferred embodiment , the water content of the lactate powder is less than 3 . 0 wt . %, more preferably less than 2 . 5 wt . %, most preferably less than 2 wt . %. the lactate content of the present powder preferably is at least 20 wt . %, more preferably at least 30 wt . % and most preferably at least 40 wt . %. the lactate powder typically comprises 1 - 20 wt . %, more preferably 2 - 18 wt . % and most preferably 4 - 16 wt . % cationic calcium , based on the total weight of the powder . in an embodiment , the powder typically comprises 5 - 45 mol %, more preferably 8 - 40 mol %, more preferably 10 - 35 mol % cationic calcium , relative to lactate . cationic sodium is typically contained in the powder in a concentration of 1 - 25wt . %, more preferably 2 - 20 wt . % and most preferably 2 . 5 - 16 wt . %, based on the total weight of the powder . in an embodiment , the powder typically comprises 5 - 80 mol %, more preferably 10 - 70 mol %, more preferably 15 - 60 mol % cationic sodium , relative to lactate . lactate powders having particularly useful properties can be obtained if calcium and sodium are contained in the powder in a molar ratio that is within the range of 0 . 1 - 5 , even more preferably in a molar ratio that is within the range of 0 . 2 - 4 and most preferably within the range of 0 . 3 - 3 . according to a preferred embodiment at least 50 wt . % of the alkali metal contained in lactate powder is sodium . even more preferably at least 70 wt . %, yet more preferably at least 80 wt . % and most preferably at least 90 wt . % of the alkali metal contained in the lactate powder is sodium . typically , the combination of calcium lactate and sodium lactate constitutes more than 50 wt . % of the total weight of the powder . in accordance with an advantageous embodiment , the powder largely consists of calcium lactate and sodium lactate . accordingly , it is preferred that the combination of calcium lactate and sodium lactate constitutes , more than 80 wt . % of the lactate powder , and most preferably more than 90 wt . % of the lactate powder . besides calcium lactate and sodium lactate , the present powder may suitably contain one or more other components . one aspect of the invention concerns the incorporation of one or more fast - dissolving carbohydrates . as noted before , the inventors established that the addition of fast - dissolving carbohydrates may further enhance the dissolution profile of the lactate containing powder . suitable examples of fast - dissolving carbohydrates that may be used in accordance with the invention include fast - dissolving polysaccharides , fast - dissolving oligosaccharides , mono -, di - and trisaccharides , and fast - dissolving poly - alcohols . particularly preferred saccharides are selected from the group consisting of lactose , glucose , sucrose , fructose , dextrines , dextrates and mixtures thereof . preferred polyalcohols in accordance with the invention are selected from the group consisting of mannitol , sorbitol , xylitol , lactitol and mixtures thereof . the fast - dissolving carbohydrate employed in the lactate powder is preferably selected from lactose , sucrose , glucose , fructose , dextrines , dextrates , mannitol , sorbitol , xylitol , lactitol , and combinations thereof . most preferably , the saccharide is glucose , lactose or mannitol . advantageously , the lactate powder contains 1 - 50 wt . %, more preferably 5 - 45 wt . %, more preferably 10 - 40 wt . %, more preferably 15 - 35 wt . % of the one or more fast - dissolving carbohydrates . in case the lactate powder contains the aforementioned fast - dissolving carbohydrates , preferably calcium lactate , sodium lactate and the fast - dissolving carbohydrate together constitute more than 80 wt . % of the lactate powder , preferably more than 90 wt . % of the lactate powder the lactate powder of the present invention typically has a volume weighted mean particle size of 50 - 1000 μm . even more preferably , the volume weighted mean diameter of the powder is in the range of 50 - 750 μm , most preferably in the range of 100 - 500 μm . the aerated bulk density of the lactate powder preferably lies within the range of 350 - 850 kg / m 3 . more preferably , the aerated bulk density of the powder is in the range of 400 - 850 kg / m 3 , most preferably of 425 - 850 kg / m 3 . the tapped bulk density of the lactate powder preferably lies within the range of 500 - 950 kg / m 3 . more preferably , the tapped bulk density of the powder is in the range of 550 - 900 kg / m 3 , most preferably of 575 - 900 kg / m 3 . the lactate powder according to the present invention may be produced in different manners , e . g . by drying an aqueous liquid containing the dissolved lactate salts and optional other ingredients . it is also feasible to prepare the lactate powder by dry blending the different lactate salts and other optional ingredients . according to a particularly preferred embodiment , the lactate powder is produced by drying an aqueous liquid that contains dissolved calcium lactate and sodium lactate . thus , the lactate powder is preferably composed of particles that contain lactate , calcium and sodium in the same relative amounts . even more preferably , the lactate powder is composed of particles having the same composition . according to an alternative embodiment , the present lactate powder comprises a blend of calcium lactate particles and sodium lactate particles . in accordance with one aspect of this embodiment the calcium lactate particles and the sodium lactate particles together constitute at least 80 wt . %, more preferably at least 90 wt . % of the lactate powder . in accordance with another aspect of the latter embodiment , the lactate powder comprises a blend of calcium lactate particles , sodium lactate particles and particles of saccharide . the calcium lactate particles , the sodium lactate particles and the particles of saccharide together preferably constitute at least 80 wt . %, most preferably at least 90 wt . % of the lactate powder . the lactate powder of the present invention preferably is composed of particles that are largely amorphous , i . e . that contain only limited amounts of crystalline material . preferably , at least 85 wt . %, most preferably at least 90 wt . % of the lactate powder is in an amorphous state . the lactate component of the present powder can suitably be produced by fermentation . according to a particularly preferred embodiment , the lactate powder is prepared from a culture broth containing a high level of lactate . the fermentation can typically be done using naturally selected lactobacilli or bacilli . for those of ordinary skill in the art it is routine practice to produce lactic acid fermentation broths that can suitably be processed into a powder of this invention . after fermentation , the broth contains primarily lactate as well as some residual components of the fermentation medium , such as carbohydrates , proteins and peptides . in particular , besides lactate such a fermentation broth typically contains appreciable levels of fermentation components selected from , sucrose , glucose , ( hydrolyzed ) protein , yeast extract paste , non - lactate based salts , alkaline components such as calcium hydroxide or sodium hydroxide , biomass formed as effect of the fermentation , etc . in an embodiment , a lactate powder is thus provided containing 0 . 1 - 40 wt . %, more preferably 1 - 30 wt . % and most preferably 5 - 20 wt . % of such fermentation components . for example , in an embodiment , the lactate powder contains , besides lactate , calcium cations and sodium cations , 10 - 15 wt . % lactose and / or 1 - 2 wt . % nitrogen and / or 0 . 1 - 5 wt . % residual biomass . another aspect of the invention relates to a method of producing a lactate powder as defined herein before , said method comprising the steps of : providing an aqueous liquid comprising a stoichiometric mixture of lactate and metal cations , said metal ions including calcium ions and sodium ions , said calcium ions and said sodium ions being present in a molar ratio that is within the range of 0 . 1 - 5 ; and drying the aqueous liquid to a water content of less than 3 . 5 wt . %. the lactate powder may suitably be formed during the drying step , e . g . by breaking up the aqueous liquid into small droplets and removing the water from these droplets , e . g . by spray drying . alternatively a solution is sprayed on an agitated bed to form particles of the desired composition . a drying step is usually included in such a process . alternatively , the powder may be produced by first drying the aqueous liquid to produce a dry residue ( e . g . by means of drum drying ) and optionally by subsequently reducing the size of the dry residue by , for instance , grinding , milling or cutting . alternatively , a blend of the materials with the desired composition is produced starting with pure ingredients . preferably drying of the aqueous liquid comprises spray drying of the aqueous liquid . in the present method , prior to the spray drying , aqueous liquid may be concentrated by evaporation . preferably , the aqueous liquid has a dry matter content of 1 - 80 wt . %, most preferably of 10 - 60 wt . % when it is fed into a spray dryer . as explained herein before , it can be advantageous to incorporate saccharide in the lactate powder of the present invention . accordingly , in a preferred embodiment , the aqueous liquid further comprises a saccharide or poly alcohol , said saccharide being selected from the group consisting of lactose , glucose , sucrose , fructose , dextrines or dextrates and combinations thereof . most preferably , the saccharide is glucose or lactose . the polyalcohol is preferably selected from mannitol , sorbitol , xylitol , lactitol , and mixtures thereof . according to a particularly preferred embodiment , the aqueous liquid employed in the present method is a fermentation broth , notably a fermentation broth that is obtained by fermenting a suitable medium with a micro - organism selected from lactobacilli or bacilli . yet another aspect of the present invention relates to a process of producing a product selected from a foodstuff , a beverage , a pharmaceutical product and a nutritional formulation , said process comprising the dissolution of a lactate powder as defined herein before in an aqueous liquid phase and incorporating said aqueous liquid phase in the product . the aforementioned process typically comprises combining the lactate powder with one or more other edible or potable ingredients other than water . preferably , lactate powder is combined with the one or more other edible or potable ingredients in an amount of 0 . 1 - 5 .% by weight of the product . anhydrous calcium lactate was produced by exposing calcium lactate pentahydrate to a 100 ° c . environment with dry air for a period of around 3 hrs . the moisture content of this product was 1 . 1 % proving that the material is essentially free of water and amorphous . solid sodium lactate was used as such as solid material . mannitol and glucose were used as such . lactose was made amorphous by freeze drying a solution of lactose in water . for dissolution test mixtures of total weight of 2 gram were produced . starting materials were accurately weighed in a plastic cup and two glass beads with a diameter of 6 mm were added . the blend was manually mixed for 1 min . to prevent water uptake , the air was purged with dry nitrogen . dissolution tests were performed by adding the test sample to 198 gram demineralized water which was stirred with a stirring flea . the test conditions are such that sink conditions are always fulfilled ( i . e . after complete dissolution of the material concentration in the liquid is less than around 30 % of saturation solubility . times to reach 10 %, 50 %, 90 % and 95 % ( t ( 10 ), t ( 50 ), t ( 50 ) and t ( 95 ), respectively ) of complete dissolution were calculated . different blends of calcium lactate pentahydrate or calcium lactate anhydrate and sodium lactate have been produced using a tumbling mixer . the samples have been stored in hermetically sealed glass jars to prevent any moisture exchange . the samples have been stored at temperatures of 4 ° c ., room temperature ( around 18 - 22 ° c .) and 40 ° c . the properties of the powders have visually been assessed at different time - points . the figure illustrates that blend containing calcium lactate anhydrate and sodium lactate stays a free - flowing powder . the blend containing calcium lactate pentahydrate and sodium lactate form a cake . all samples containing calcium lactate anhydrate and sodium lactate were free flowing powders , the table summarizes the visual observations of the blends containing calcium lactate pentahydrate to quantify the degree of cake formation , a mixture containing 20 % sodium lactate and 80 % calcium lactate pentahydrate has been stored at a temperature of 40 ° c . for a period of 5 days in a cylinder used for the purpose of testing the unconfined fracture strength of cylindrical specimen . after storage for 5 days at a temperature of 40 ° c ., a cake with a fracture strength of 8 kpa was formed when calcium lactate pentahydrate was present . the material was still flowing meaning that the unconfined fracture strength could not be measured when a mix based on anhydrous calcium lactate was tested . calcium lactate pentahydrate was placed in a fluidized bed equipped with a top spray system . the ( set point ) inlet air temperature was 100 ° c . during fluidization . sodium lactate solution containing 60 % sodium lactate was sprayed on fluidized calcium lactate to form particles in a calcium lactate to sodium lactate ratio of 1 : 1 and 4 : 1 respectively . dissolution time was detected according to the method in example 1 . table 3 shows the dissolution results . a lactic acid ferment was produced having ( relative ) amounts of lactate and calcium and sodium cations according to this invention . the raw ferment was not purified and processed into a powder having the composition indicated in table 4 by spray - drying . the product temperature during the spray - drying process was 90 ° c ., the air temperature varied between 165 and 180 ° c . dissolution time has been determined according to the methodology described in example 1 . the average dissolution time of this raw ferment was 32 s .
the present invention relates to a lactate powder , more particularly a lactate powder having a lactate content of at least 20 wt . % and a water content of less than 3 . 5 wt . %, said powder comprising calcium cations as well as sodium cations . according to the invention , a calcium lactate powder combining high stability with excellent water dissolution properties can be obtained even though anhydrous calcium lactate represents the bulk of the powder if the powder additionally contains a certain amount of sodium lactate . the inventors have found that the presence of sodium lactate greatly improves the dissolution behavior of the anhydrous calcium lactate while maintaining the storage stability of the powder . the present inventors also established that the dissolution behavior of the powder can be further improved by the addition of a fast - dissolving carbohydrate material .