METHOD FOR FIXING VOLATILE FLAVORANTS IN EXTRUDED VITREOUS SUBSTRATES

Abstract: The present invention provides a method for fixing vol­ atiles in an extruded glass substrate. A minor component consisting of a low molecular weight water-soluble carbo­ hydrate or food acid is dry-blended with a major component consisting of a high molecular weight water-soluble poly­ meric carbohydrate in a ratio of from 10% to 30% low mo­ lecular weight carbohydrate or adipic, malic or citric acids or combinations thereof to at least 70% high molecular weight material. A volatile flavorant like orange oil or acetaldehyde is combined with this substrate mixture. The dry-blended mixture is extruded at a temperature which is essentially at or below the melting point of the minor ingredient but above the glass transition state of the substrate. The free-­ flowing powder is relatively non-hygroscopic and possesses a high fix.

Description: DESCRIPTION FIXATION OF VOLATILES IN EXTRUDED GLASS SUBSTRATES BACKGROUND OF THE INVENTION TECHNICAL FIELD The present invention generally relates to a method for fixing volatile flavorants in a foodapproved substrate, and more particularly to a low-temperature methodology for fixing volatile flavorants in an extruded "carbohydrate-glass" substrate. The problems involved in the storage and utilization of volatile flavorants, and specifically essential oils, in dry form, are greatly complicated by the extreme sensitivity of substrate constituents to the effects of heat, light, air and moisture. Therefore, there has been a longstanding need for a food-approved encapsulation substrate which is essentially solid and moisture-stable A promising technique to solve the problems attendant to the fixation of highly volatile flavorants, is via encapsulation of the highly volatile flavorant in a moisture-stable substrate. One such method is by extrusion, although spray-drying of flavors on a dextrin or other carbohydrate substrate is a common technique. United States Patent 3,041,180 issued to Swisher discloses a method for fixing flavorants in an extruded carbohydrate substrate according to the following methodology. The product of the Swisher invention is obtained by emulsifying an essentially water-insoluble essential oil with a molten mixture of glycerol and corn syrup solids as the continuous phase, extruding the emulsified mass in the form of filaments into a cold fluid, preferably an organic solvent for the essential oil which is a nonsolvent for the corn syrup solids, followed by impact breaking of the solidified filaments into small particles of usable form and then holding the particles in the solvent, preferably for an extended period to remove essential oil from the surfaces of the particles, together with a substantial portion of the residual moisture contained on and in the particles. This methodology is conducted in excess of 1300C. SUMMARY OF THE INVENTION The present invention provides a methodology for fixing a volatile flavorant in an extruded "carbohydrate-glass" substrate. Moreover, the present method eliminates the following: maintaining the admixture at high temperatures is not necessary; emulsifiers or glycerine-type plasticizers are not required; the present invention allows the volatile or essential oil to be dry-blended (i.e., no added moisture) at ambient temperatures with the components of the substrate directly, or to be metered into the dry substrate materials. The method employed herein relies solely on the extrusion of ingredients enumerated hereinbelow to form a glass. Extrusion temperature is regulated so that it is above the glass transition state of the substrate but at or below the melting point of the minor ingred ient, the low molecular weight ingredient which may be a low molecular weight carbohydrate, a food-acid or combinations thereof, comprising from 10%-30% of the substrate. For example, when one uses maltose monohydrate and a malto-dextrin having a D.E. (dextrose equivalent) of about 10, the extrusion is carried out at or below 1000C since maltose monohydrate has a melting point of about 102 -103 C. The glass transition temperature of the substrate mixture is less than the melting point of the low molecular weight ingredient. To employ the present methodology, one mixes the minor component and the major component with a volatile flavorant. The minor component is a low molecular weight (90-500 molecular weight) watersoluble crystalline carbohydrate or food acid material. This "minor" component is responsible for from 10% to 30% by weight of the substrate. The major component which is at least 70% by weight of the substrate mixture is a material which contains at least 95% high molecular weight polymeric carbohydrate materials, (above 1,000). The major and minor components are admixed or dry-blended with the volatile flavorant that one wishes to encapsulate. There is no need to add moisture to the dry-blended mixture. The admixture is extruded within a temperature range as described hereinbelow. Unlike other methods, the present invention involves exposing both substrate and volatile flavorant to relatively short periods of elevated temperature. The product formed thereby retains flavorant levels up to about 15%, and is moisture-stable, free-flowing and of high density after the extrudate is ground. DETAILED DESCRIPTION The present methodology includes the steps outlined hereinbelow, wherein "dry" ingredients, inclusive of a volatile flavorant, are admixed or dry-blended, and extruded within a critical temperature range as follows. For illustrative purposes the substrate materials shall include a polymeric carbohydrate material containing predominately high molecular weight carbohydrate constituents; a maltodextrin is such a material. The malto-dextrin is preferably of a D.E. of from 5 D.E. 20 D.E. One dry blends from 10% to 30% of a low molecular weight material, such as a monosaccharide or disaccharide with at least 70% of a malto-dextrin, said malto dextrin possessing by weight less than 5% monosaccharides and disaccharides. For the minor ingredient component, a carbohydrate of low molecular weight may be used. The preferred low molecular weight carbohydrates are: fructose, glucose, maltose and mannose. To these components, the volatile flavorant is added. Another class of materials may be operatively substituted for low molecular weight carbohydrates. Food-approved acids display similar utility. For purposes of the present invention food-approved acids shall include adipic acid, citric acid and malic acid. In addition, these acids may be combined with low molecular weight carbohydrates, with the combination comprising the low molecular weight component. An illustrative combination of ingredients for use in the present invention shall be composed of LO-DEX 10, a maltodextrin, maltose monohydrate and orange oil. Although the type of extruder appears to be immaterial, for purposes of the present invention, a Brabender Extruder (manufactured Brabender Corp., South Hackensack, New Jersey) will be used for illustrative purposes. The extrusion, carried out within a Brabender extruder, is characterized by a zonal temperature differential. The present invention is designed to operate within a specific temperature range. The extrusion temperature should be above the glass transition state of the substrate mixture, but at or below the melting point of the minor ingredient. Extrusion above the preferred range results in a lowered fix, but if the extruder temperature is not high enough the "glass" substrate will not form. As one can see by the Examples set out hereinbelow, temperatures, including die temperatures exceeding melting points of minor ingredients inhibit the fixative qualities of the substrate. When using conventional food extruders it is often necesssary to use die temperatures that exceed the melting point of the minor ingredient. While it is perferable to restrict die temperatures to the parameters set out hereinbelow an elevated temperature is often necessary when one uses small diameter die apertures. An elevated die temperature may be necessary to prevent clogging of the die aperture and to facilitate outflow of the extrudate; however, the extrudate would be exposed to such elevated die temperatures for relatively short periods of time. Still, it has been found that most preferably the die temperature should not greatly exceed the melting point of the minor ingredient, with the efficacy of the method decreasing with increased die temperatures. Thus the extrusion will occur essentially at or below the melting point of the minor ingredients. The volatile flavorants shall be characterized, for purposes of the present invention as essential oils or low boiling point volatiles. For example, in orange oil, the volatile constituents include acetaldehyde, terpenes, esters, and alcohols. In the present method, other volatiles or essential oils may be operatively substituted herein. The examples set out hereinbelow, are for illustrative purposes and are not meant to in any way limit the present invention. EXAMPLE I 125 g of maltose-monohydrate (Sigma Chemical Co., St. Louis, Missouri) and 375 g of LO-DEX 10 (manufactured by Amaizo American Maize Products Company, Hammond, Ind.) were mixed in a five-quart Hobart-type mixer (manufactured by Hobart Inc., Hawthorne, New York). 20 ml (17.6 g) of ethylbutyrate was added to the above-stated combination. The whole system was allowed to mix for an additional 1.5 minutes. During the mixing period the blending apparatus was covered to minimize volatile loss, if any. The homogenous mixture was placed in the feed end of the extruder. The type of extruder was a Brabender multi-zoned extruder. This type of extruder possesses a single screw within a .75 inch diameter barrel. This type of extruder employs independently controlled temperature zones, with the die-head temperature being elevated above barrel temperature as a result of friction and as a means of assuring unimpeded outflow of the extrudate. Extrusion conditions are as follows: Zone Number: I II III Die Temperature: No Heat 980C 980C 1050C The glass transition temperature of the substrate mixture is about 800C. The extruder has a screw ratio of 2:1, a one-quarter inch die and a shear rate of 60 rpm. The admixture was fed through the extruder so that a uniform rope was obtained which was allowed to cool to ambient temperature. The product was a very homogenous (glassy) material wherein flavor was entrapped. Chemical analysis (gas chromatography) was conducted showing little flavor loss after extrusion. The initial ethylbutyrate fix by the extrusion method was found to be 3.5% by weight and after 3 days having been ground (to -16 + 25 U.S. Sieve screen mesh sizes) the fix remained at this level. EXAMPLE 2 125 g mannose (M.P. 1330C) and 375 g LO-DEX 10 were mixed together for 3 minutes to which 20 g of lemon oil (terpeneless, lot #2347 from Citrus and Allied Essenses, Ltd., Floral Park, New York) was mixed for 2 minutes. The mixture was extruded in a Brabender extruder. The operative conditions follow: Zone Number: I II III Die Temperature: 600C 1200C 1300C 1250C A screw ratio of 2:1 was used with a die measuring .25 inches having a shear rate of 80 rpm. The product was a stable glassy "structure" wherein the initial lemon oil fix was 3.6% by weight and after 3 days of open storage in a ground (-16 + 25 U.S. Sieve mesh size) condition the fix was found to be stable at 3.3% by weight. EXAMPLE 3 125 g maltose-monohydrate and 375 g LO-DEX 10 were mixed together for 3 minutes, to said mixture 20 g of orange oil (terpeneless, lot #3358 from citrus and Allied Essenses, Ltd., Floral Park, New York) was mixed for 2 minutes. The homogenous mixture was extruded in the Brabender extruder under the following conditions. Zone Number: I II III Die Temperature: 500C 1000C 1000C 1050C A screw ratio of 2:1, and a .25 inch die with a shear rate of 60 rpm was applied. The resulting product was a hard, glassy structure which was found to have an initial fix of 2.5% by weight. 10 grams of the ground material was put into an open beaker and retained therein for 3 days after which the fix was found to be stable at 1.8% by weight. EXAMPLE 4 To study the effect of extrusion variables on fixation of orange oil the following example was carried out using high maltose corn syrup (HMCS) and citric acid. Dry high maltose corn syrup (HMCS) solids was obtained first by spray drying the syrup with 30% (wt.) Lodex 10 in an Anhydro dryer. This dry solid will be called HMCS mix. 614.3 g Lodex 10, 285.7 g HMCS mix (70% HMCS + 30% Lodex 10) and 100 g citric acid monohydrate were blended together (dry powder) as in Example I. 52.6 g of orange oil (terpeneless, lot #2395 from citrus and Allied Essences, Ltd.) were added to the dry mix and blended together for an extra 3 minutes. Extrusions were made using a multiple hole die (-1/16" diameter holes) with a single screw Brabender type extruder. The zone and die temperatures were fixed at present conditions to study the efficiency of retaining the orange oil. On extrusion, followed by cooling cord-like (¯1/8") strands were obtained which could be easily broken into small pieces. The level of orange oil was analyzed before and after extrusion. The data are given in the table (#1). TABLE I Extruder Orange oil Zone Area I II III Die Level Run #A 350C 800C 900C 120 4.64% B 350C 800C 900C 110 3.10% A relatively high orange oil fix 4.64% (5.0% before extrusion) was obtained when the extrusion conditions were fixed as in Run #A above. EXAMPLE 5 2716 g of LO-DEX 10 and 1087 g high maltose corn syrup (HMCS) mix (70% HMCS and 30% LO-DEX 10 See Example 4) were dry mixed for 2 min. in a Hobart bowl. 200 g of orange oil (terpeneless) were added to the dry mix and all were blended together for an additional 2 min. (covered bowl). Extrusions were made using a multiple hole die with a single screw Brabender type extruder. Very uniform cord-like strands (-2 mm diameter) were obtained after extrusion with varying orange oil retentions depending on the extrusion condition as outlined in Table II: TABLE II Extruder Zone Temperature Fixed Orange Run # I I II III Die Oil wt.% A 250C 60OC 800C 120-1250C 1.71 B 25 60 80 115-117 3.14 C 25 60 80 104-105 2.79 D 25 60 80 98-100 4.71 E 25 60 80 130 1.98 F 25 60 90 118-120 3.00 It is evident that excessively high die temperatures ( > 120 C) should be avoided for efficient orange oil fixation. In fact, exceeding the melting point of the minor ingredient even for short periods of time decreases the ability for the substrate to fix volatile flavorants.

Claims: CLAIMS 1. A method for fixing a volatile flavorant in an extruded glass substrate comprising the steps of: (a) dry-blending a minor substrate component of from 10-30% of a low molecular weight water soluble carbohydrate, a food-approved acid or combinations thereof, and at least 70% of a high molecular weight water-soluble polymeric carbohydrate material as a major substrate component with up to 15% by weight of said minor and major components of a volatile flavor ant to form a homogenous mixture; and (b) extruding said mixture within a temperature range that is above the glass transition state of the substrate and essentially at or below the melting point of minor ingred ients, to form an amorphous substrate and to entrap said flavorant therein. 2. The method according to Claim 1 wherein the low molecular weight water-soluble carbohydrate is chosen from the group consisting of maltose, mannose, glucose, high maltose corn syrup and combinations thereof. 3. The method according to Claim 1 wherein the low molecular weight water-soluble food-approved acid is chosen from the group consisting of adipic acid, citric acid, malic acid and combinations thereof. 4. The method according to Claim 1 wherein the low molecular weight water soluble material is a crystalline carbohydrate. 5. The method according to Claim 1 wherein the low molecular weight water-soluble carbohydrate is from 90-500 molecular weight and possesses a melting point of from 800C to 1800C. 6. The method of Claim 1 wherein the polymeric carbohydrate is of an average molecular weight above 1000 molecular weight. 7. The method according . to Claim 1 wherein the polymeric carbohydrate is a malto-dextrin having a dextrose equivalent of from 4 D.E. to 20 D.E. 8. A method according to Claim 1 wherein the volatile flavorant is an essential oil. 9. A method according to Claim 1 wherein the volatile flavorant possesses a boiling point of from 20"C to 200"C. 10. A product made according to the process described in Claim I wherein the polymeric carbohydrate is a malto-dextrin having a D.E. of 10. 11. A product made according to the process described in Claim 1 comprising about 25% maltose and about 75% malto-dextrin having a D.E. of from 5 to 15.

Inventors: PICKUP, JOHN GEORGE, SALEEB, FOUAD ZAKI
Applicants: GENERAL FOODS CORPORATION
Application year: 1985
Main classification: A23L1
IPC codes: A23L1