while aspartame is the preferred dipeptide sweetener of the present invention , aspartame is only functional in the present invention when it is hydrated with between about 0 . 02 and about 1 part water per each part aspartame . however , it is preferred that the aspartame be hydrated with between about 0 . 02 and about 0 . 5 parts water for each part aspartame . it is further preferred that the aspartame contain between about 0 . 02 and about 0 . 3 parts water per part aspartame . moreover , it is essential that the aspartame be substantially in a crystalline form and that at least some of the water is water of crystallization , and preferredly some water is absorbed on the surface of the aspartame . while any lipid may be useful in the present invention , it is preferred that the lipid component be selected from the group composed of hydrocarbons , aliphatic alcohols , aliphatic acids , esters of aliphatic acids , glycerol containing lipids and combinations thereof . it is more preferred that the lipid component of the present invention be selected from the group composed of aliphatic acids , esters of aliphatic acids , glycerol containing lipids and combinations thereof . aliphatic fatty acids esters are more preferred and the aliphatic fatty acid esters of glycerol are the most preferred lipids of the present invention . examples of aliphatic fatty acid triesters useful in the present invention comprise tallow , lard , cocoa butter , palm oil , palm kernel oil , coconut oil , cotton seed oil , peanut oil , rape seed oil , corn oil , safflower oil , sunflower oil , soy bean oil and combinations thereof . glycerol diesters , propylene glycol diesters , and combinations thereof are examples of aliphatic fatty acid diesters useful in the present invention . fatty acid monoesters useful in this invention comprise : monoglycerides , propylene glycol and monostearate and combinations thereof . moreover , it is preferred that the fatty acid residues of the esters consist essentially of saturated , unsaturated , and polyunsaturated aliphatic acids containing between about 10 and about 30 carbon atoms , and combinations thereof . the hydrated dipeptide sweetener is combined with at least about 1 but less than about 100 parts of lipid for each part of the dipeptide sweetener . however , it is preferred that at least about 3 ; more preferably at least about 5 ; and most preferably at least about 10 parts of lipid are combined with each part dipeptide sweetener . furthermore , it is preferred that less then about 30 parts and more preferably , less than about 20 parts of lipid are combined with each part dipeptide sweetener . typically , this admixture is heated to a temperature above about 25 ° c ., preferably to a temperature above about 50 ° c . additionally , the dipeptide sweetener - lipid admixture is agitated so as to thoroughly blend the components . nonetheless , it is preferred that the admixture is kept at or below the temperature at which the lipid used decomposes , a temperature commonly known as the lipid &# 39 ; s smoke point . it is further preferred that the admixture temperature be kept at least 10 ° c . below this lipid decomposition temperature or smoke point . it is also preferred that the lipid temperature , at the time the aspartame is combined with the lipid , is less than the temperature at which aspartame , if heated alone , would decompose . thus it is preferred that the lipid temperature at the time the lipid component and the aspartame are combined is less than about 195 ° c ., and more preferably this temperature is less than about 175 ° c . however , once the aspartame lipid gel has started to form , the admixture may be heated to the lipids decomposition temperature even if this temperature exceeds the aspartame decomposition temperature without destroying the gel . while it is possible to incorporate additional ingredients or materials into the dipeptide sweetener - lipid admixture before the gel &# 39 ; s formation , some additional ingredients will , at some concentrations , inhibit or prevent the gel &# 39 ; s formation , e . g . large amounts of water . thus it is also preferred that the dipeptide sweetener - lipid combination contain other materials at a level less than the level at which the other materials are effective to inhibit the gel &# 39 ; s formation . the heating step in the process of the instant invention may be accomplished by any conventional heating means including : conduction , convection , radiation , microwave , and combinations thereof . the time and temperature of heating necessary to produce the thermally irreversible thixotropic gel of the present invention are inversely related . thus , the higher the temperature to which the admixture is heated , the shorter the necessary heating period . however , the admixture should be heated for about at least 10 seconds and preferably at least about 30 seconds , and most preferably , the admixture is heated for at least about 5 minutes . nonetheless , the dipeptide sweetener - lipid admixture is preferably heated for less than about 72 hours . as a result of this heating , unlike most fluids , the viscosity of the admixture increases . minimumly , the admixture should be heated at a temperature and for a time effective to produce at least about a 100 % ( 1 . 0 fold ) increase in the viscosity . this increase in the viscosity is determined by measuring the viscosity of the admixture ; subtracting the viscosity of the lipid with the dipeptide sweetener added at the instant the dipeptide sweetener was added to the lipid from the viscosity of the admixture ; and dividing this quantity by the viscosity of the lipid with the dipeptide sweetener added at the instant the dipeptide sweetener was added to the lipid . all of these viscosity measurements are made at the same temperature , which temperature is above the lipid component &# 39 ; s melting point or range . restated , the increase in viscosity is determined by the following formula : η l is the viscosity of the lipid and dipeptide sweetener combination at the point in time at which the dipeptide sweetener is added to the lipid . thus , η l compensates for the increase in viscosity due to the presence of an additive dispersed in the lipid . in most cases η l will be approximately equal to the viscosity of the oil alone . however , it is preferred that the heating be for a time and at a temperature effective to produce a viscosity increase about at least about 1 , 000 % ( 10 ) and more preferably at least about 10 , 000 % ( 100 ). nonetheless , the viscosity increase is preferably less than about 10 7 fold . while viscosity may be measured in a number of ways , the brookfield hat viscometer is an especially preferred instrument for measuring the viscosity of the gel of the instant invention . in measuring the viscosity of the gel of the instant invention with a brookfield hat viscometer , a configuration of said instrument comprising a helipath stand and either a cylindrical or a t - bar spindle is further preferred . typical use of this instrument will require placing about 200 ml of the material whose viscosity is to be measured in a 250 ml beaker . next , an appropriate spindle and rotation speed ( rpm ) is chosen for the viscometer to obtain a reading within the range of the instrument &# 39 ; s indicator . then , using for example the helipath stand and a t - bar spindle , the instrument is turned on and the spinning spindle is allowed to penetrate the sample . while the spinning spindle is in the sample , a dial or indicator reading is made . the dial reading is converted to a centipoise viscosity measurement by multiplying the dial reading by a factor that is appropriate for the spindle and the speed of rotation used . thus , the &# 34 ; f &# 34 ; t - bar rotating at 0 . 5 rpm dial reading is multiplied by 4 × 10 5 , and the # 2 cylindrical spindle rotating at 50 rpm dial reading is multiplied by 16 . wesson ™ oil , 90 gm was combined with 10 gm of aspartame . the moisture of the aspartame was varied from 0 to 2 . 3 parts water per part aspartame among these examples . the oil - aspartame admixture was heated to 100 ° c . for 30 minutes with mixing . at 43 ° c ., the example 1 admixture had a viscosity ( η l ) of 100 centipoise ( cps ). this value was used to calculate δη in example 2 - 14 as well . after the heating and mixing step , the examples had the following viscosities ( η a ) and viscosity increases ( δη ), also at 43 ° c . : ______________________________________ parts water per partexample aspartame η . sub . a ( in cps ) δη ( in cps ) ______________________________________1 0 100 02 0 . 04 30 , 000 2993 0 . 11 30 , 000 2994 0 . 25 1 , 600 155 0 . 42 700 66 1 . 00 50 - 0 . 57 2 . 3 50 - 0 . 5______________________________________ the negative δη observed in examples 6 and 7 is partially due to a dilution effect as a result of adding the relatively large amounts of water , 5 to 7 ml respectively , to the oil - aspartame system in these examples . the admixture viscosities , after heating , are plotted in fig1 as a function of the aspartame percent moisture . examples 1 - 7 were repeated with hydrol 92 ™ oil , a partially hydrogenated coconut oil . after the heating and mixing step , these samples had the following viscosities ( η a ) and viscosity increases ( δη ), also at 43 ° c . : ______________________________________ parts water per partexample aspartame η . sub . a ( in cps ) δη ( in cps ) ______________________________________ 8 0 336 2 . 3 9 0 . 04 140 , 000 139910 0 . 11 200 , 000 199911 0 . 25 12 , 000 11912 0 . 42 900 813 1 . 00 320 2 . 214 2 . 3 40 - 0 . 6______________________________________ the results of example 8 - 14 were very similar to the results for example 1 - 7 . cocoa butter , 100 gm , was heated to 36 ° c . so as to melt the fat . aspartame , 5 gm , with a 4 % moisture , was added to the melted cocoa butter and the admixture was blended . the admixture was allowed to cool to ambient temperature , and said cooling hardened the admixture . thereafter , the admixture was heated to and maintained at 100 ° c . for 30 minutes . the admixture was then cooled again and combined with 100 gm of chocolate liquor . the admixture was thoroughly blended and formed a sweet , good - tasting , chocolate spread that does not melt at 37 ° c . ( body -- hand -- temperature ). however , shear , such as that of chewing , breaks the chocolate spread gel down to produce a desirable melted chocolate mouthfeel . at 36 ° c ., cocoa butter has a viscosity of 74 cps and after the admixture had been heated to 100 ° c . for 30 minutes , the mixture had a viscosity of 10 5 cps . when the gel was cooled to 38 ° c . it had a viscosity of 2 . 5 × 10 6 cps . as a comparison , a hershey ® bar at 38 ° c . has a viscosity of 6 . 4 × 10 4 cps . wesson ™ oil , 55 gm , was heated to 100 ° c . and then combined with 5 g aspartame . the aspartame had a 4 % moisture . the admixture was kept at 100 ° c . for 20 minutes . thereafter , 30 gm of cocoa powder and 125 gm of powder sugar were added to the admixture . the combination was then cooled to 55 ° c . and mixed well in a waring ® blender . the product was then formed into bars to make a chocolate - like product without cocoa butter . the following ingredients were dry blended to form a reduced - calorie cake mix : ______________________________________swan &# 39 ; s down ® cake flour 121 . 0cellulose flour 50 . 5egg white solids 10 . 0non - fat milk solids 5 . 0baking soda / baking powder 6 . 0emulsifier 3 . 0gum 2 . 0salt , vitamins , and flavors 1 . 5______________________________________ separately , 20 gm vegetable shortening was heated to 100 ° c . to melt . to this melted shortening , 4 gm aspartame having 4 % moisture were added . thereafter , the admixture was blended for 3 minutes in a home blender at high speed . the blended admixture was again heated to 100 ° c ., this time for 5 minutes . next , the shortening - aspartame gel was cooled to ambient temperature . the above cake mix and the gel at ambient temperature were mixed vigorously for 5 minutes with a wire wisk . once this mixing is completed , 273 gm water were added to the cake mix - gel admixture and mixed at high speed with an electric mixer for 3 minutes . the entire batter was then transferred into a greased , 8 inch ( 0 . 2 m ) round cake pan and baked for 35 minutes in a pre - heated , 176 ° c . oven . after baking , the cake was cooled , and tasted . the tasters who evaluated the cake stated that it was sweet and good tasting and was sweeter tasting than a cake made from the same ingredients without first forming the gel . a sufficient quantity of soya hard fat flakes ( a partially hydrogenated soybean oil ) were melted to obtain an excess of the melted fat flakes . a 160 . gm aliquot of the melted fat was weighed out . separately , a sufficient quantity of sorbitan fatty acid ester was also melted . an 80 . gm aliquot of the melted sorbitan ester was combined with the melted , measured fat and the combination was mixed . the combined fat and sorbitan ester was kept at a temperature just sufficient to maintain the melted state of the combination . without cooling , the combined fat and sorbitan ester , 80 . gm of a waxy corn starch was added and mixed into the melt . thereafter , 80 . gm of aspartame were added to the melted fat - sorbitan ester - starch combination and the mixture was blended . as the aspartame was being blended into the combination , a powder was formed . this powder was sweet , hard and free - flowing . a 2400 gm force was required to deform the example 18 sample 1 mm . contrastingly , a 47 gm force deformed the example 2 sample 1 mm . wesson ™ oil , 80 gm were heated to 100 ° c . and combined with 20 gm aspartame containing 4 % moisture . the combination was well mixed and kept at 100 ° c . for 30 minutes . upon cooling to ambient temperature , a hard , sweet gel resulted . an oven was preheated to 260 ° c . and the gel placed inside the oven for 10 minutes . when removed after the 10 minutes , the gel had changed color and was brownish . additionally , the gel was smoking and had a off - smelling character to it . however , when cooled to ambient temperature , the gel was still very sweet tasting . the gel was placed in the oven for an additional 10 minutes , after which the gel was substantially as it had been after the first 10 minutes in the oven . however , after the gel had been returned to the oven for a third 10 minute period , the gel was only moderately sweet , and after a fourth 10 minute period in the oven , the gel was not sweet . partially hydrogenated coconut oil , 25 gm , were heated to 100 ° c . and combined with 3 . 5 gm aspartame containing 4 % moisture . the combination was well blended and kept at 100 ° c . for 30 minutes . this combination was then cooled to ambient temperature to produce the gel in example 20 . this gel , 5 . 7 gm were then combined with the following ingredients to produce a model beverage system example 20 . in example 21 , 5 gm of the partially hydrogenated oil and 0 . 7 gm of the aspartame containing 4 % moisture were separately added to the other model beverage system ingredients . ______________________________________ingredient amount ( in gm ) ______________________________________water 971 . 0citrate - phosphate buffer & gt ;. 1effective to producea ph of 3 . 0sodium benzoate 1 . 0gum 15 . 0colorant 0 . 1______________________________________ examples 20 and 21 were stored at 43 ° c . and aliquots of each were removed and analyzed for the amount of aspartame remaining , as a percent of the aspartame originally in each example , at each of the times indicated below . ______________________________________ % aspartame remainingtime ( in days ) example 20 example 21______________________________________0 100 1002 94 . 7 93 . 55 85 . 2 83 . 29 78 . 5 75 . 813 72 . 7 68 . 322 57 . 3 52 . 5______________________________________ thus , analytically , the gel significantly stabilized the aspartame in the model beverage system . examples 20 and 21 were both stored at 43 ° c . and a duplicate of example 21 was stored at 7 ° c . these samples , both temperature example 21 samples and the example 20 sample , were brought to 4 ° c . and evaluated for sweetness by a trained taste panel . the trained panel reported the following relative sweetness levels , at the following times , for each sample . ______________________________________time 7 ° c . 43 ° c . 43 ° c . ( in days ) example 21 example 20 example 21______________________________________ 8 5 5 416 5 5 424 5 4 432 5 3 . 5 440 5 1 1______________________________________ in examples 22 - 25 , 1 part of aspartame with 4 % moisture was combined with 9 parts of a lipid component at 77 ° c . the lipid component in each example was varied as specified in the table below . the combination was mixed well for 30 seconds while the temperature was maintained at 77 ° c . additionally , the viscosity of the combination was measured at various times and is also reported in the table below . furthermore , several aliquots of the combinations were cooled to ambient temperatures and their sweetness was evaluated . __________________________________________________________________________ gel viscosity as a function of both lipid and time__________________________________________________________________________ η . sub . l η . sub . a η . sub . a η . sub . a ( lipid & amp ; apm ) ( lipid & amp ; apm ) ( lipid & amp ; apm ) ( lipid & amp ; apm ) example lipid composition lipid η time = &# 34 ; 0 &# 34 ; time = 0 . 5 hour time = 1 hour time = 2__________________________________________________________________________ hrs . 22 wesson oil ™ 100 136 30 , 000 35 , 000 75 , 000 ( mainly triglycerides ) 23 durlo ™ ( a mixture 100 22 , 000 400 , 000 450 , 000 500 , 000 of mono , di and triglycerides ) 24 atmos ™ ( a mixture 100 14 , 000 180 , 000 210 , 000 225 , 000 of mono and diglycerides ) 25 myverol ™ ( mainly 100 80 , 000 350 , 000 350 , 000 400 , 000 monoglycerides ) __________________________________________________________________________ η . sub . a η . sub . a η . sub . a η . sub . a η . sub . a ( lipid & amp ; apm ) ( lipid & amp ; apm ) ( lipid & amp ; apm ) ( lipid & amp ; apm ) ( lipid & amp ; apm ) examplelipid composition time = 4 hrs . time = 5 . 5 hrs . time = 21 hrs . time = 48 hrs . time = 96__________________________________________________________________________ hrs . 22 wesson oil ™ 200 , 000 700 , 000 1 , 200 , 000 920 , 000 840 , 000 ( mainly triglycerides ) 23 durlo ™ ( a mixture 600 , 000 2 , 500 , 000 2 , 400 , 000 1 , 800 , 000 740 , 000of mono , di andtriglycerides ) 24 atmos ™ ( a mixture 250 , 000 90 , 000 52 , 000 78 , 000 78 , 000of mono and diglycerides ) 25 myverol ™ ( mainly 400 , 000 115 , 000 160 , 000 66 , 000 80 , 000monoglycerides ) __________________________________________________________________________ * all viscosities are in centipoise example 22 , the wesson ™ oil sample , was sweet at all times , but after 21 hours , the sample was slightly less sweet then the sample originally had been . ( wesson oil ™ is comprised substantially of -- at least 90 % is -- triglycerides ). example 23 , the durlo ™ sample , was not sweet when tested after 1 hour . however , after 3 hours , the durlo ™ sample was slightly sweet . example 24 , the atmos ™ sample , was not sweet after 10 minutes , but was sweet after 3 hours . similarly , example 25 , the myverol ™ sample , was not sweet after 10 minutes , but was sweet after 2 hours . it was also observed that the gel comprising wesson oil ™, example 22 , was thixotropic : when the gel was subjected to considerable shear forces , the viscosity of the example 22 gel decreased considerably . however , when the example 22 gel was allowed to sit , it recovered its original viscosity . on the other hand , the viscosity of examples 23 and 25 did not substantially decrease when subjected to shear forces . during the first 3 hours , the viscosity of the example 24 gel did not decrease when the gel was subjected to shear forces . however , after 8 days , the viscosity of the example 24 gel dropped from 1 . 6 × 10 6 cps to 8 × 10 4 cps when the gel was subjected to shear forces , and upon sitting , the example 24 gel did not recover its initial viscosity . a lemon oil sample , 87 parts , was combined with 13 parts of 4 % moisture aspartame at 10 ° c . the combination was well mixed and then heated to 100 ° c . until a solid - like substance was formed . when the mixture was cooled to ambient temperature , the resulting gel had an intense lemon character and was very sweet . ( a ) soften 27 parts of a gum base by heating to 60 ° c . ; ( b ) add 13 parts of sorbitol and 4 parts of mannitol to the gum base in a mixer , blend the admixture while controlling the termperature to between 55 ° c . and 70 ° c . ; ( c ) add 1 part lecithin , 13 parts of sorbitol , and 4 parts of mannitol and blend ; ( d ) add 1 part of dipeptide sweetener - lipid gel comprising 0 . 5 parts aspartame , 0 . 5 parts wesson oil ™ and 0 . 02 parts water and blend ; and ( e ) add 17 parts of sorbo syrup , 1 part flavor , 13 parts sorbitol , and 4 parts mannitol and blend . the above examples are given only for the purpose of illustrating the invention . all parts and percentages are by weight .
a composition which stabilizes a dipeptide sweetener , modifies the physical characteristics of a lipid , or both is disclosed . this composition comprises a hydrated , crystalline dipeptide sweetener and a lipid .