Coating agent and coated powder

A coating agent comprising (a) a modified cellulose and (b) at least one of an edible water-soluble additive and an edible polymer substance; a process for producing the coated powders; and foods and drinks containing the above-described coated powders. The coating agent can provide coated powders which are less hygroscopic, have a high storage stability and a high oxidation stability, are excellent in the release of core materials, controlled release and taste and can be favorably used for imparting or enhancing aroma and flavor in foods and drinks to be processed by heating, for example, foods for microwave cooking and baked foods.

REFERENTIAL EXAMPLE 1 Preparation of Extrusion Flavor Containing Lemon Flavor 260 g of water and 440 g of sucrose employed as a carrier were mixed with 360 g of dextrin (Pinedex &num;1, manufactured by Matsutani Chemical Industry Co., Ltd.) under heating to give a molten matter. Then 90 g of a lemon flavor (manufactured by Takasago International Corporation) was added thereto and the mixture was uniformly mixed by stirring. The resultant mixture was supplied into an extruder provided with an extrusion plate, extruded and dried to give an extrusion flavor containing the lemon flavor. 
 EXAMPLE 1 To 100 g of water was added 20 g of methylcellulose (Metolose SM-4, manufactured by Shin-Etsu Chemical Co., Ltd.) and dispersed therein with heating. Then 10 g of fructose (manufactured by Junsei Chemical Co., Ltd.) was added thereto and dissolved therein. Under cooling and stirring, 400 g of ethanol (95%, manufactured by Junsei Chemical Co., Ltd.) was added thereto to give 530 g of a homogeneous coating agent. 
 EXAMPLE 2 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 530 g of the coating agent prepared in Example 1 at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 2 to 3 g/min while maintaining the flowable state. Thus, 497 g of a coated powdered flavor was obtained. 
 EXAMPLE 3 To 100 g of water was added 20 g of methylcellulose (Metolose SM-4, manufactured by Shin-Etsu Chemical Co., Ltd.) and dispersed therein with heating. Then 10 g of sucrose (manufactured by Junsei Chemical Co., Ltd.) was added thereto and dissolved therein. Under cooling and stirring, 400 g of ethanol (95%, manufactured by Junsei Chemical Co., Ltd.) was added thereto to give 530 g of a homogeneous coating agent. 
 EXAMPLE 4 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 530 g of the coating agent prepared in Example 3 at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 2 to 3 g/min while maintaining the flowable state. Thus, 502 g of a coated powdered flavor was obtained. 
 EXAMPLE 5 To 100 g of water was added 20 g of methylcellulose (Metolose SM-4, manufactured by Shin-Etsu Chemical Co., Ltd.) and dispersed therein with heating. Then 10 g of sorbitan fatty acid ester (Sorgen FS-700, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was added thereto and dissolved therein. Under cooling and stirring, 400 g of ethanol (95%, manufactured by Junsei Chemical Co., Ltd.) was added thereto to give 530 g of a homogeneous coating agent. 
 EXAMPLE 6 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 530 g of the coating agent prepared in Example 5 at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 2 to 3 g/min while maintaining the flowable state. Thus, 500 g of a coated powdered flavor was obtained. 
 COMPARATIVE EXAMPLE 1 To 60 g of water was added 30 g of methylcellulose (Metolose SM-4, manufactured by Shin-Etsu Chemical Co., Ltd.) and dispersed therein with heating. Under cooling and stirring, 500 g of ethanol (95%, manufactured by Junsei Chemical Co., Ltd.) was added thereto to give 590 g of a homogeneous coating agent. 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 590 g of the above-described coating agent at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 2 to 3 g/min while maintaining the flowable state. Thus, 499 g of a coated powdered flavor was obtained. 
 COMPARATIVE EXAMPLE 2 200 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was thoroughly mixed with 10 g of palm hardened fat (SPFLW, manufactured by Fuji Oil Co., Ltd.) to thereby give 210 g of a coated powdered flavor. 
 EXAMPLE 7 The coated powdered flavor prepared in Example 2 was added at a ratio of 1% to a dough having the following composition and thus lemon flavored cookies were prepared. The cookies thus prepared were regarded as the invention product 1 and subjected to a sensory evaluation. 1 Component Part by weight soft wheat flour 150.0 shortening 135.0 powdery sugar 127.5 egg albumen 90.0 sodium chloride 0.75 water 22.5 
 EXAMPLES 8 AND 9 Cookies were prepared by the same method as in Example 7 but using the coated powdered flavors prepared in Examples 4 and 6 as a substitute for the coated powdered flavor of Example 2. The cookies thus prepared were regarded respectively as the invention products 2 and 3 and subjected to the sensory evaluation. 
 COMPARATIVE EXAMPLES 3 AND 4 Cookies were prepared by the same method as in Example 7 but using the coated powdered flavors prepared in Comparative Examples 1 and 2 as a substitute for the coated powdered flavor of Example 2. The cookies of Comparative Examples 3 and 4 thus prepared were regarded respectively as the comparative products 1 and 2 and subjected to the following sensory evaluation. 
 SENSORY EVALUATION 1 The cookies of the invention products 1 and 2 and the comparative product 1 were taken and evaluated in the quickness of the aroma release. As a result, the evaluation rank was as follows: the invention product 1>the invention product 2>the comparative product 1. These results indicate that the dissolution speed of methylcellulose at ordinary temperature can be controlled by adding an appropriate edible water-soluble substance. 
 SENSORY EVALUATION 2 The cookies of the invention product 3 and the comparative products 1 and 2 were subjected to a sensory evaluation by using 5 skilled panelists. The evaluation was made the following 5 grades on the aroma strength (aroma remaining during baking), and the quickness and strength of the aroma release in the mouth (the data is expressed in the average of 5 panelists). Evaluation criteria: A: very good. B: good. C: moderate. D: somewhat poor. E: poor. 2 TABLE 1 Invention Comparative Comparative product 1 product 1 product 2 Aroma strength (during baking) A A E Quickness in release (in mouth) A C C Strength (in mouth) A A C Total evaluation* 100 87 47 *The score of each panelist is expressed numerically (A &equals; 5 to E &equals; 1) and the sum (full marks &equals; 15) is shown on a maximum scale of 100 points. In the above evaluation, the skilled panelists stated that the invention product 3 was superior to the comparative product 1 in all of the items, i.e., total evaluation, aroma remaining during baking, quickness of the aroma release in the mouth and strength. That is to say, the sample containing methylcellulose and sorbitan fatty acid ester was almost comparable or somewhat superior to the sample containing methylcellulose alone in the protection of the flavor in heating. However, the former sample showed an improvement in the quickness of the aroma release in the mouth when the cookies were taken. This fact indicates that the addition of the edible water-soluble substance to methylcellulose makes it possible to improve the solubility in water after returning to ordinary temperature without reducing the effect of methylcellulose of protecting the flavor by the reversible gel formation at a high temperature. Compared with the comparative product 2 with the use of the fat commonly used as coating agents, the invention product 3 was superior in all of the items evaluated. 
 EXAMPLE 10 20 g of methylcellulose (Metolose SM-4, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 500 g of water and dispersed therein with heating. Then 10 g of pullulan (F20, manufactured by Hayashibara Co., Ltd.) was added thereto and dissolved. The obtained solution was cooled and stirred to give 530 g of a homogeneous coating agent. 
 EXAMPLE 11 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 530 g of the coating agent prepared in Example 10 at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 2 to 3 g/min while maintaining the flowable state. Thus, 500 g of a coated powdered flavor was obtained. 
 EXAMPLE 12 20 g of methylcellulose (Metolose SM-4, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 500 g of water and dispersed therein with heating. Then 10 g of maltodextrin (Pinedex &num;1, manufactured by Matsutani Chemical Industry Co., Ltd.) was added thereto and dissolved. The obtained solution was cooled and stirred to give 530 g of a homogeneous coating agent. 
 EXAMPLE 13 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 530 g of the coating agent prepared in Example 12 at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 2 to 3 g/min while maintaining the flowable state. Thus, 497 g of a coated powdered flavor was obtained. 
 EXAMPLE 14 500 g of citric acid having been ground to about 100 &mgr;m in particle size was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 530 g of the coating agent prepared in Example 5 at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 2 to 3 g/min while maintaining the flowable state. Thus, 492 g of a coated powdery acidulant was obtained. 
 EXAMPLE 15 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 2,120 g of the coating agent prepared in Example 1 at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 2 to 3 g/min while maintaining the flowable state. Thus, 528 g of a coated powdered flavor was obtained. 
 EXAMPLE 16 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 10.6 g of the coating agent prepared in Example 1 at a liquid supplying temperature of 50° C., a blowing temperature of 65° C. and an exhaust temperature of 50° C. and at a spraying speed of 20 to 25 g/min while maintaining the flowable state. Thus, 478 g of a coated powdered flavor was obtained. 
 EXAMPLE 17 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 3,180 g of the coating agent prepared in Example 5 at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 2 to 3 g/min while maintaining the flowable state. Thus, 548 g of a coated powdered flavor was obtained. 
 EXAMPLE 18 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 53 g of the coating agent prepared in Example 5 at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 2 to 3 g/min while maintaining the flowable state. Thus, 480 g of a coated powdered flavor was obtained. 
 EXAMPLE 19 20 g of methylcellulose (Metolose SM-4, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 500 g of water and dispersed therein with heating. Then 0.2 g of dextrin (Pinedex &num;1, manufactured by Matsutani Chemical Industry Co., Ltd.) was added thereto and dissolved. The obtained solution was cooled and stirred to give 520.2 g of a homogeneous coating agent. 
 EXAMPLE 20 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 520.2 g of the coating agent prepared in Example 19 at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 2 to 3 g/min while maintaining the flowable state. Thus, about 500 g of a coated powdered flavor was obtained. 
 EXAMPLE 21 20 g of methylcellulose (Metolose SM-4, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 500 g of water and dispersed therein with heating. Then 12 g of gelatin (AP-200, manufactured by Nitta Gelatin Inc.) was added thereto and dissolved. The obtained solution was cooled and stirred to give 532 g of a homogeneous coating agent. 
 EXAMPLE 22 500 g of the extrusion flavor containing the lemon flavor of Referential Example 1 was supplied into a Multiplex Model MP-01 (manufactured by Powrex Corporation). Then it was coated by spraying 532 g of the coating agent prepared in Example 21 at a blowing temperature of 60 to 65° C. and an exhaust temperature of 30 to 70° C. and at a spraying speed of 20 to 25 g/min while maintaining the flowable state. Thus, 487 g of a coated powdered flavor was obtained. Each of the powdered flavors obtained in the above Examples 11, 13, 15 to 18, 20 and 22 had the same properties as the powdered flavors of Examples 1, 3 and 5. The coated powdery acidulant of Example 14 was stable at a high temperature and yet excellent in the properties of releasing the acidulant into water upon cooling. As described above in detail, coated powders which are excellent in the release of core materials, controlled release and taste and can be favorably used for imparting or enhancing aroma and flavor in foods and drinks to be processed by heating, for example, foods for microwave cooking and baked foods can be produced by using coating agent comprising modified celluloses together with edible water-soluble additives and/or edible polymer substances. By using these coated powders in foods for imparting or enhancing aroma and flavor, prepared foods free from the vaporization of aroma and flavor even in cooking by, for example, a microwave oven can be obtained. While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the scope thereof. This application is based on Japanese patent application No. 2001-129850 filed Apr. 26, 2001, the entire contents thereof being hereby incorporated by reference.