the present inventor discovered that surfactants and more particularly anionic surfactants effectively enhance the dewatering of gluten in vacuum dewatering equipment . typically , in the processing of corn gluten the dewatering operation is the limiting factor in gluten recovery . conventionally , the dewatering of gluten is a multiple step operation comprising centrifuge dewatering followed by vacuum dewatering and thereafter drying . the vacuum dewatering equipment limits gluten production rates due to the time consuming nature of the operation . it has been discovered that adding anionic surfactants , particularly sulfates and sulfonates , at concentrations of 100 to 2500 ppm ( based on treatment actives content and the dry solids content of the gluten slurry ) enhances the efficiency of the mechanical dewatering process by reducing the gluten effluent moisture . laboratory tests demonstrated that this moisture can be reduced by approximately 1 to 2 % absolute , which translates to a process energy reduction of 225 to 475 btu per standard bushel of corn , assuming typical wet milling process yields . while efficacy at dosage levels below 100 ppm was not tested , it is anticipated that an improved dewatering effect of these treatments would occur . the level of treatment dosage will depend on the particular corn gluten slurry being treated . all tests were conducted using process samples provided by a major u . s . corn wet milling facility . samples were composed of concentrated gluten slurry after the dewatering centrifuge and before the rotary vacuum filter . a standard filter leaf test apparatus was used to simulate the rotary vacuum filter . the media assembly was modified to allow filter paper to be used instead of filter cloth . this eliminated any potential residual effect in sequential treatment testing , as well as gradual fouling of the cloth with proteins in the gluten . the experiments consisted of placing the gluten slurry sample at approximately 110 ° f . into an agitated beaker . the vacuum level was established at 17 &# 34 ; hg . the beaker agitation was stopped , and the media assembly inserted into the gluten . after allowing 30 seconds for the cake to form , the assembly was removed from the beaker and inverted to allow drainage of filtrate from the assembly . vacuum was maintained for an additional 30 seconds to simulate the cake drying time found in industrial rotary vacuum filters . the cake was then analyzed for percent moisture using a standard oven method . experimental results are shown in tables i and ii , below . note that negative values may be attributable to e . g ., adhesion of free starch to the fiber , daily variations in the control ( untreated ) data , etc . table 1______________________________________effect of sulfates on gluten filter cake moisture moisture reductiontreatment dosage ( ppm ) ( control - treated , %) ______________________________________sodium alkyl aryl 500 0 . 73polyether sulfate 2500 1 . 16sodium 2 - ethyl - 1 - hexyl sulfate 100 - 0 . 34 250 - 0 . 02 500 1 . 36 2500 1 . 59sodium dodecyl sulfate 100 1 . 62 250 0 . 30 500 1 . 44 2500 0 . 71______________________________________ table ii______________________________________effect of sulfates on gluten filter cake moisture moisture reductiontreatment dosage ( ppm ) ( control - treated , %) ______________________________________sodium linear 100 0 . 18alkylbenzene sulfonatemagnesium sulfonate 250 - 0 . 79 500 1 . 41 2500 1 . 62sodium hexadecyl diphenyl 250 - 0 . 21ether disulfonate 500 1 . 63 2500 0 . 66sodium sulfonate 100 0 . 40 500 0 . 79 2500 1 . 81sodium octyl sulfonate 100 1 . 15 250 0 . 36 500 0 . 90 2500 0 . 63sodium α - olefin sulfonate 500 0 . 18 2500 1 . 09sodium dodecylbenzene 500 0 . 38sulfonate 2500 0 . 54α - olefin sulfonate 250 - 0 . 67 500 0 . 64 2500 1 . 35______________________________________ these tests indicate that anionic surfactants , particularly sulfates and sulfonates , at dosages o 100 to 2500 ppm ( based on treatment actives content and the dry solids content of the gluten slurry ) are effective in reducing the effluent cake moisture in corn gluten rotary vacuum filters by approximately 0 . 5 to 2 . 0 percent . sulfates and sulfonates appeared to be the most effective anionic surfactants in improving the dewatering of gluten in laboratory tests . the sulfates and sulfonates listed should be considered representative of sulfates and sulfonates in general and should be regarded solely as illustrative without restricting the scope of the invention . sodium dodecyl sulfate ( commonly referred to as sodium lauryl sulfate ) and sodium octyl sulfonate yielded cake moisture reductions at dosages as low as 100 ppm active , dry solids basis . sodium 2 - ethyl , 1 - hexyl sulfate , at dosages of 500 and 2500 ppm reduced filter cake moisture nearly as much as sodium dodecyl sulfate at 100 and 500 ppm . sodium alkyl aryl polyether sulfate , sodium hexadecyl diphenyl ether disulfonate , and α - olefin sulfonate also demonstrated efficacy at various concentrations . additional anionic materials were tested . results are found in table iii , below . table iii______________________________________effect of other anionic materials on starch filter cake moisture moisture reductiontreatment dosage ( ppm ) ( control - treated , %) ______________________________________dioctyl sodium sulfosuccinate 500 - 0 . 35 2500 0 . 21phosphated mono - and 100 - 0 . 87di - glyceridesn - lauroyl , n , n . sup . 1 , n . sup . 1 - 500 0 . 57ethylenediaminetriacetic acid______________________________________ while this invention has been described with respect to particular embodiments thereof , it is apparent that numerous other forms and modifications of this invention will be obvious to those skilled in the art . the appended claims and this invention generally should be construed to cover all such obvious forms and modifications which are within the true spirit and scope of the present invention .
methods of enhancing the dewatering of gluten are disclosed . the methods comprise adding an anionic surfactant to the wet gluten prior to dewatering , as in vacuum dewatering equipment . particularly effective surfactants are sulfates and sulfonates .