NZ767663B2 - Frozen dessert, soft ice cream, frozen dessert raw material and production method for frozen dessert - Google Patents

Abstract

Provided is a frozen dessert, a soft ice cream and a frozen dessert raw material having a long holding time from when it starts to melt to when it falls and melts with its viscosity, texture and flavor maintained, and a production method for the frozen dessert. The frozen dessert contains hydroxypropyl methylcellulose. The hydroxypropyl methylcellulose includes a methoxy group and a hydroxypropoxyl group as substituents, which improves the shape retention of the frozen dessert.

Description

FROZEN DESSERT, SOFT ICE CREAM, FROZEN DESSERT RAW MATERIAL AND PRODUCTION METHOD FOR FROZEN DESSERT [Technical Field] The present invention relates to a frozen dessert, a soft ice cream, a frozen dessert raw material and a production method for the frozen dessert.

[Background Art] Frozen desserts are roughly classified into "hard ice creams" and "soft ice creams." The "hard ice creams", which are in the form of end products obtained through a "hardening step" in a production process to be described later, are distributed in a frozen state at approximately - °C, and placed in a freezing cabinet for sales as merchandises at a store. The "hard ice creams" are categorized into "ice creams" and "ice confections" here.

The "soft ice creams" are made with a frozen dessert production apparatus in a store without a "hardening step," and sold face to face to consumers without being distributed as prepared food products at approximately -4 to -10°C after directly taken out of the frozen dessert production apparatus at the store. The "soft ice creams" are also categorized into "ice creams" and "ice confections" here.

For hard ice creams and soft ice creams, the "ice creams" are categorized into an ice cream standard, an ice milk standard and a lacto-ice standard (lacto-ice is a Japanese frozen dessert category containing milk solid of 3% or more) based on the compositional standards for ice creams stipulated by Ministerial Ordinance on Milk.

For hard ice creams and soft ice creams, the "ice confections" are frozen desserts containing less than 3% of milk solid, and are further categorized into fat-containing ice confections and fat-free ice confections.

Consumers may eat a hard ice cream at a store immediately after purchase, or may take it home by maintaining its frozen state with dry ice or the like, keep it in a freezer and eat it at an appropriate timing. Since the hard ice cream immediately after it is taken from the freezer is frozen very hard, it is usually left to at a room temperature so that the temperature thereof is raised to approximately -10°C, at which it is soft enough to eat, and it thaws of its own accord by leaving it at room temperature.

However, the thawing time taken until a hard ice cream is soft enough to eat varies greatly depending on the surrounding environment. As time goes by, the surface of the hard ice cream may start melting earlier than the other part and impair a dry feeling, an edge portion of the hard ice cream twisted high into a sharp and beautiful shape may run down and ruin the shape, or the hard ice cream may melt and fall like a snowslide. Thus, consumers often miss the timing to eat a hard ice cream while it is in an ideal state.

When a small child or an elderly person cannot quickly eat a cold frozen dessert, the frozen dessert often starts melting completely and gets their hands or clothes dirty, or melts and falls like a snowslide and drips onto the floor.

In the case of a soft ice cream that is made at a store without the hardening step, served in an edible container such as a cone cup or the like in a soft state at approximately -4 to -10°C and sold face to face, consumers eat the soft ice cream in or around the store while holding the container such as a cone cup. Then, the soft ice cream melts with time and gets the hands and clothes of the consumers dirty, or the soft ice cream melts and falls like a snowslide and drips onto the floor, necessitating cleaning. Such problems occur more often when the ambient temperature is high.

In these frozen desserts, which melt with time unless they are kept in a frozen state, it is important to maintain a dry feeling by delaying start of melting as much as possible, maintain a beautiful shape by delaying a melting and falling time (time until ice cream melts and falls) as much as possible and maintain a beautiful appearance perceptually appealing attractive taste (reinforcing shape retention) leading to improvement of product’s value (product’s life). These are critical as well as other properties such as flavor and texture.

As a conventional method for the reinforcement of the shape retention of frozen desserts, addition of a stabilizer and an emulsifier is known. Examples of the stabilizer include hydrophilic polysaccharides extracted from seaweed, vegetable seeds, microorganisms; insoluble polysaccharides such as microcrystalline cellulose; and synthetic stabilizers such as carboxymethylcellulose (CMC). Examples of the emulsifier include low HLB emulsifiers such as unsaturated fatty ester.

Patent Document 1 states that use of microcrystalline cellulose, carrageenan and waxy starch as stabilizers allows for enhancement of the liquid stability of a liquid soft ice cream mix before the freezing and achievement of soft ice cream having good shape retention and superior drip resistance after the freezing for a long period of time. Patent Document 2 states that inclusion of micronized cellulose and microcrystalline cellulose provide high spreadability and smooth texture.

[Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent Application Laid-Open Publication No. H5-276875 [Patent Document 2] Japanese Patent Application Laid-Open Publication No. H6-178659 [Summary of the Invention] [Problems to be Solved by the Invention] The inventors of the present inventions have made intensive studies for prolonging the time period from when a consumer starts to eat a frozen dessert until melting, falling and loss of shape start, that is, extending the period of time during which a frozen dessert can retain its shape (improvement in shape retention). As a result, the present inventors have reached the following findings.

The improvement in shape retention of a frozen dessert with polysaccharide thickener can be achieved by increasing the amount of the stabilizers to be added. However, addition of the stabilizers to the extent that an expected effect is achieved makes the texture of the frozen dessert pasty, significantly impairing the texture of the frozen dessert.

The improvement of the shape retention of a frozen dessert with low HLB emulsifiers can also be achieved by increasing the amount of the emulsifiers to be added. However, the emulsifiers have a distinctive taste and odor, and addition of the emulsifiers to the extent that an expected effect is achieved thus reduces the flavor of the frozen dessert.

The present invention is made in view of such circumstances, and the object of the present invention is to provide a frozen dessert, a soft ice cream and a frozen dessert raw material having a long holding time from when it starts to melt to when it falls and melts while maintaining viscosity, texture and flavor, and a production method for the frozen dessert.

[Means for Solving Problems] A frozen dessert according to the present invention contains hydroxypropyl methylcellulose.

[Effect of the Invention] According to the present invention, a long shape retention time is obtained while the viscosity, texture, flavor, etc. of an ice cream are maintained.

A soft ice cream is desired to have extended time before it starts to melt and fall and is thus more suitable as an exploitation of the present invention.

[Brief Description of Drawings] is a flowchart showing a production process of frozen desserts of an embodiment of the present invention. is a graph showing a relation between the HPMC content of a lacto ice standard and the holding time. is a graph showing the holding times of Examples 4, 7 and 8 and Comparative Example 2. is a graph showing the holding times of Examples 4 and is graph showing a relation between the number of sterilization processes by a frozen dessert production apparatus and the holding time. is a graph showing a relation between the HPMC content of an ice cream standard and the holding time. is a graph showing the holding times of Examples 11 and 13-14 and Comparative Examples 3 and 4. is a graph showing the holding times of Example 15 and Comparative Example 5. is a graph showing a relation between a fat content of the lacto ice standard and the holding time. is a graph showing the holding times of soft ice creams in Examples 4 and 16-18 and Comparative Examples 1 and 6-10.

[Modes for Carrying Out the Invention] (Summary of Embodiments) A frozen dessert according to the present embodiment contains hydroxypropyl methylcellulose (hereinafter referred to as HPMC).

HPMC is represented by the following formula (1).

[Formula I] R = - H, - C H - C H - C H- O H [DELETED] In the cold dessert according to the present embodiment, a fat content is preferably 3% by weight or more.

If the fat content is 3% by weight or more, emulsification and demulsification of the fat globule are well balanced, improving in shape retention. For unsaturated fatty ester used by balancing of emulsification and demulsification of a fat globule, problems of distinctive taste and odors occur. Such problems do not occur in the frozen dessert according to the present embodiment.

Preferably, in the frozen dessert according to the present embodiment, a time period from when the frozen dessert is put in an incubator maintained at 35°C and having circulated air to when the frozen dessert melts and falls is 130 seconds or more. If the time period until the frozen dessert melts and falls is 130 seconds or more, it is possible to prevent a problem of melting the frozen dessert and getting the hands and clothes of the consumers dirty during eating, or melting and falling of the frozen dessert like a snowslide and dripping onto the floor.

Preferably, in the frozen dessert according to the present embodiment, a substitution degree of a methoxy group of the HPMC is from 19% to 30%, and a substitution degree of a hydroxypropoxyl group of the HPMC is from 4% to 12%. In this case, the above- described effects can be exerted.

In the frozen dessert according to the present embodiment, the HPMC content is preferably 0.01% by weight to 0.5% by weight. If the HPMC content is less than 0.01% by weight, an effect of extending the time period until melting and falling of a frozen dessert cannot be found. If the HPMC content is more than 0.5% by weight, a frozen dessert has slimy and poor texture.

A soft ice cream according to the present embodiment is a frozen dessert contatining hydroxypropyl methylcellulose and produced without undergoing a hardening step.

A soft ice cream is more likely to start melting, melt and fall, or lose its shape with time than a hard ice cream since it does not undergo the hardening process. According to the above-described composition, the time until melting and falling is delayed, and the occurrence of these problems can thus be prevented.

A frozen dessert raw material according to the present embodiment contains hydroxypropyl methylcellulose.

According to the above-described composition, a frozen dessert having the extended time until melting and falling can be obtained.

A production method for the frozen dessert according to the present embodiment includes producing the frozen dessert from the frozen dessert raw material containing hydroxypropyl methylcellulose.

According to the above-described composition, a frozen dessert having an extended time until melting and falling can be obtained.

(Frozen Dessert Raw Material) In the present embodiment, the raw materials other than HPMC included in frozen dessert raw material are appropriately selected from raw materials commonly used for frozen desserts, for example, water, milk, dairy products, sweeteners, oils and fats, stabilizers, emulsifiers, flavoring agents, salt, fruit juices and fruit pulp according to the type of the frozen dessert.

Examples of the milk include, but are not limited to, cow milk, and defatted milk (skim milk). Examples of the dairy products include, but are not particularly limited to, skim milk powder, modified milk powder, cream, condensed milk and fermented milk.

The milk and the dairy products may be used independently, or two or more kinds may be used in combination.

Examples of the sweeteners include, but are not particularly limited to, sugars such as sugar (sucrose), grape sugar (glucose), fruit sugar (fructose), malt sugar (maltose), milk sugar (lactose), trehalose, starch syrup and isomerized sugar; sugar alcohols such as sorbitol, xylitol, maltitol, erythritol and lactitol; and non-sugar sweeteners such as aspartame, sucralose, acesulfame K, stevioside, thaumatin, glycyrrhizin, saccharin and dihydrochalcone. The sweeteners may be used independently, or two or more kinds may be used in combination.

The oils and fats are used as an essential component of the ice cream depending on the type of the frozen dessert to be produced finally. Examples of the oils and fats include, but are not particularly limited to, vegetable oils such as palm tree oil, palm oil, palm kernel oil, soybean oil and canola oil; and animal oils and fats such as lard, tallow and fish oil. Milk fats such as butter and cream may also be used. The oils and fats may be used independently, or two or more kinds may be used in combination.

The stabilizers moderately increase the viscosity of a frozen dessert raw material and prevent the oil and fat component from being separated from a frozen dessert raw material during the production process, storage or distribution. The stabilizers are also used for controlling the size of the ice crystals in the ice cream and improving the texture of the ice cream. Examples of stabilizers include, but are not particularly limited to, plant-derived stabilizers such as carrageenan, guar gum, locust bean gum, microcrystalline cellulose, pectin, starch and gum arabic; animal-derived stabilizers such as gelatin, casein and casein Na; and synthetic stabilizers such as carboxymethyl cellulose (CMC). The stabilizers may be used independently, or two or more kinds may be used in combination.

The emulsifiers have a function of dispersing fat. Insufficient dispersion of fat makes it difficult to well perform a sterilization step and a homogenization step. The emulsifiers have an effect on the overrun, dryness and texture. Examples of emulsifiers include, but are not particularly limited to, glycerin fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester and propylene glycol fatty acid ester. The emulsifiers may be used independently, or two or more kinds may be used in combination.

The flavoring agents (flavors) are not limited as long as they give desired fragrance to the frozen dessert, and examples thereof include vanilla, chocolate, coffee, strawberries, apples, oranges, grapes, cinnamon, sweet melons, bananas, peaches, mangos, mint and lemons. The flavoring agents may be used independently, or two or more kinds may be used in combination.

(Preparation of Frozen Dessert Raw Material) is a flowchart illustrating a production process for a frozen dessert according to the present embodiment. The frozen dessert of the present invention is produced, distributed and sold according to the process shown in the flowchart in shows the production processes of "ice cream type" concerning a "soft ice cream" and a "hard ice cream" while "ice creams" and "ice confections" are substantially the same in production process. It is noted that for "ice confections," a homogenization step and an aging step may be omitted.

In the blending step, HPMC as well as the raw materials such as water, milk, a dairy product, a sweetener, oil and fat, a stabilizer, an emulsifier, a flavoring are placed in a tank mixer as a blending apparatus and uniformly stirred and mixed to give a precursor mixture referred to as "premix," which is a mix before heat sterilization. It is preferable that the pre-mix has an HPMC content from 0.01% by weight to 0.5% by weight. In the blending process, the amount of each material other than HPMC is calculated in advance in view of the amount of addition of HPMC.

In the blending process, preliminary heating may be performed in order to uniformly dissolve and mix the raw materials. The temperature of the preliminary heating is not particularly limited, but is 50°C to 80°C is appropriate, for example.

In the sterilization step (heating step), a commonly known continuous heating method such as Ultra-High-Temperature (UHT) sterilization, or High-Temperature Short Time (HTST) sterilization can be employed. The sterilization method is not limited to these methods, and batch-wise or continuous indirect heating methods can also be employed, for example. It is noted that sterilization step may be performed after the homogenization step.

In the homogenization step, the premix prepared in the blending step is moved to a homogenizing apparatus, and this homogenizing apparatus breaks down the milk fat and fats and oils in the premix, to homogenize the premix. As the homogenizing apparatus, conventionally-known homogenizers, homomixers, colloidal mills and the like may be used. Some material mixes of frozen desserts that are free from fats and oils are completely dispersed or dissolved in the blending process. In the case of such material mixes, the homogenization process may be omitted.

In the cooling step, the mix after the heat sterilization is cooled rapidly. If the hot mix after the sterilization step is left as it is, the mix may undergo degradation and demulsification. The degradation and the demulsification of the mix are thus avoided by rapidly cooling the mix after the sterilization step.

Next, the production process of a hard ice cream will be described first, and then the production process of a soft ice cream will be described.

In the case where the frozen dessert raw material prepared is an ice cream mix, by aging the mix after the cooling step for about several hours to two days (cooling temperature: 5 to 10°C), the components in the mix will be stabilized, and satisfactory ice cream will be obtained for freezing.

The mix after the aging step is put in a frozen dessert production apparatus (freezer), and cooled to a predetermined temperature while the mix and air are being stirred and mixed at a predetermined ratio to thereby make an air-containing creamy ice cream.

After the freezing step, a required amount of the completed ice cream is put in a required container using a filling machine.

Conventionally-known packaging containers in line with the purpose may be used as the container for being filled.

Examples of the container material include, but are not limited to, cup containers, bulk containers, pillow containers and standing pouches made from processed paper and plastic materials. As the filling machine, commonly-known apparatuses may be used according to the application.

The ice cream put in a container may be further packaged.

Hardening is performed to freeze the ice cream after completion of the filling process. The hardening may be performed using commonly-known equipment to cool and harden the ice cream.

Examples of the method thereof include, but are not limited to, a method by applying cold air at -30°C to -40°C and a method by using the vaporization heat of liquid nitrogen. Rapid freezing is desirable since the hardening speed has an effect on the growth of ice crystals of the ice cream at the hardening step.

The hardened ice creams are kept frozen, distributed, delivered to each store, and then placed in a freezing cabinet for sale.

Next, production process for the soft ice cream will be described.

In the case where the frozen dessert is a soft ice cream, a required amount of a soft ice cream mix which has been cooled is put in a required container using a filling machine.

Conventionally-known packaging containers in line with the purpose may be used as the container for being filled. Examples of the container include, but are not limited to, Tetra Pak (Registered Trademark) cartons and Gable top cartons made from processed paper, and pillow containers and bags for bag-in-boxes (BIBs) made from plastic materials. As the filling machine, commonly-known apparatuses may be used according to the application. The filling may be performed under aseptic conditions or under non-aseptic conditions. In the case where the filling is performed under aseptic conditions, long-term distribution and storage at room temperature are possible. Examples of the filling machine to be used under aseptic conditions include, but are not limited to, aseptic filling machines available from Tetra Pak International S.A. The soft ice cream mix filled in a container may be further packaged.

Examples of the packaging include, but are not limited to, packing in a cardboard box.

The liquid soft ice cream mix packed in a cardboard box or the like is stored and distributed under a room temperature, or refrigeration or frozen condition and delivered to each store.

Cream Mix> Examples of a production method for a soft ice cream using a liquid soft ice cream mix distributed to each store includes a production method to be described below.

The liquid soft ice cream mix produced at a factory are filled in a container and distributed to each store. The liquid soft ice cream mix is put in the frozen dessert production apparatus at a store, and cooled to a predetermined temperature of -4°C to -10°C while the soft ice cream mix and air are being stirred and mixed at a predetermined ratio to thereby make an air-containing creamy ice cream. The ice cream in a creamy state is taken out from a freezer according to the order of a customer, is served in a cone cup so as to be twisted high into a sharp from down to up, and sold at the store face to face to consumers in a creamy state just made at the store without the hardening step and distribution.

The soft ice cream mix packed in a box is stored and distributed under a room temperature, refrigerated or frozen condition and delivered to each store.

[Example] Examples of the present invention will be described below.

However, the present invention is not limited thereto. 1. Soft Ice Cream of Lacto Ice Standard (1) Relation between HPMC Content and Holding Time The relation between the HPMC content and the holding time was studied. Hereafter, the time until a soft ice cream melts and falls is referred to as a holding time. The compositions of a soft ice cream mix base of the lacto-ice standard are as follows.

[Soft Ice Cream Mix Base of Lacto-Ice Standard] Sugars, dairy products, oils and fats, emulsifiers, stabilizers and other components such as water were used as raw materials to prepare a soft ice cream mix base of the lacto-ice standard of Comparative Example 1 to be described below at the ratios of the raw materials shown in Table 1. Sugar and starch syrup were used as the sugars; skim milk powder, etc. were used as the dairy products; palm tree oil and palm oil were used as the oils and fats; cellulose, casein Na and thickening polysaccharides were used as the stabilizers; and a vanilla flavoring agent and a caroten pigment were used as the other components.

[Table 1] Table 1 Component % by weight Sugar 17.1 Dairy product 6.4 Oil and fat 6.0 Emulsifier 0.5 Stabilizer 0.5 Other component 0.2 Water 69.3 Sum 100 [Example 1] As an example of the HPMC, HPMC (Product Name METOLOSE (registered trademark) "NE-100" available from Shin- Etsu Chemical Co., Ltd.) was used. A soft ice cream mix of the lacto-ice standard in Example 1 was prepared by mixing the component material of the soft ice cream mix base of the lacto-ice standard described above with the HPMC so that the HPMC content would be 0.01% by weight. More specifically, the preparation was made such that the amount of the sugars to be added was subtracted by the corresponding amount of the added HPMC with respect to the ratios of the raw materials shown in Table 1 described above.

Subsequently, 1.7 L of the soft ice cream mix of Example 1 was put into a frozen dessert production apparatus (freezer NA6462WE, produced by Nissei Co., Ltd.). One hour after the start of freezing, approximately 110 g (approximately 140 ml) of soft ice cream was taken out and served in a cone cup (No. 15 cone, produced by Nissei Co., Ltd.) by twisting upward the soft ice cream three and a half turns to produce the soft ice cream of the lacto-ice standard of Example 1.

[Examples 2-6] Soft ice creams of Examples 2-6 were produced in the same manner as in Example 1 except that the component materials of the soft ice cream mix bases were blended with the HPMC so that the HPMC content would be 0.03% by weight, 0.05% by weight, 0.10% by weight, 0.30% by weight and 0.50% by weight, respectively.

[Comparative Example 1] A soft ice cream of Comparative Example 1 was produced in the same manner as Example 1 except that no HPMC was included.

Holding times were measured for soft ice creams of Examples 1- 6 and Comparative Example 1 by the following measurement method, and the texture thereof, etc. were evaluated.

[Measurement of Holding Time] The soft ice creams produced in Examples 1-6 and Comparative Example 1 were put in an incubator ("IC101W" manufactured by Yamato Scientific Co., Ltd.) maintained at 35°C having circulated air inside by a compact fan ("BSOTOS08WH" manufactured by BUFFALO INC.), and the cone cup was supported in an upright position with a cup holder on a plate in the incubator. The door was closed so that external air would not enter, and the soft ice cream was observed as it melted and fell. In doing so, the time from when the soft ice cream was put in the incubator to when the soft ice cream on the cone cup melted and fell onto the plate was measured. Eight times of measurements were performed, and the measurement results were averaged to obtain a holding time.

[Evaluation of Texture] The soft ice creams of Examples 1-6 and Comparative Example 1 were eaten, and the quality of the soft ice creams in terms of texture, mouth feel (viscosity) and flavor was studied. The results are shown in Table 2. The basis for evaluation is as follows: A...good B...little slimy and poor texture The measurement results of the holding times and the evaluation results of the texture, etc. are shown in Table 2 below and The horizontal axis of the graph in represents the HPMC content (wt%) while the vertical axis thereof represents the holding time (in seconds).

[Table 2] Table 2 Example Example Example Example Example Example Comparative 1 2 3 4 5 6 Example 1 NE-100 0.01% 0.03% 0.05% 0.10% 0.30% 0.50% 0% Holding time 03'30'' 09'39'' 12'54'' 15'44'' 17'48'' 21'04'' 03'12'' Standard 00'30'' 04'17'' 02'51'' 03'58'' 02'08'' 01'52'' 00'54'' deviation Evaluation result of A A A A A B A texture, etc.

Table 2 and show that Examples 1-6 containing the HPMC are improved in holding times as compared to Comparative Example 1 not containing HPMC. In the case of the HPMC content of 0.5% by weight, a little slimy and a poor texture were obtained. It is preferable that the HPMC content is from 0.01% by weight to 0.50% by weight. The lower limit of the HPMC content is more preferably 0.02% by weight, while the upper limit of the HPMC content is preferably 0.40% by weight, more preferably 0.30% by weight, or even more preferably 0.25% by weight. (2) Relation between Holding Time and Substitution Degree of Methoxy Group and Substitution Degree of Hydroxypropoxyl Group of HPMC The relation between the substitution degree of methoxy group and the substitution degree of hydroxypropoxyl group of HPMC and the holding time was studied.

[Examples 7 and 8] Soft ice creams of Examples 7 and 8 were produced in the same manner as in Example 4 except that as the HPMC, METOLOSE "SE-50" and "SFE-400" (commercially available from Shin-Etsu Chemical Co., Ltd.) were used. The HPMC content was 0.10% by weight.

[Comparative Example 2] A soft ice cream of Comparative Example 2 was produced in the same manner as in Example 4 except that methylcellulose ("MCE- 100" commercially available from Shin-Etsu Chemical Co., Ltd.) was used in place of the HPMC.

The specifications of the products "NE-100," "SE-50," "SFE-400" and "MCE-100" as well as "NE-4000" to be described later and the measured values are shown in Tables 3 and 4.

[Table 3] Table 3 Substitution degree 2% viscosity Gelatification Methoxy Hydroxypropoxyl temperature (mm /s) group group NE-100 19-24% 4-12% 80-120 70-90 ? SE-50 28-30% 7-12% 40-60 55-75 ? SFE-400 27-30% 4-7.5% 280-560 60-75 ? MCE-100 25-33% - 80-120 50-55 ? NE-4000 19-24% 4-12% 2800-5600 70-90 ? [Table 4] Table 4 Substitution degree 2% viscosity Methoxy Hydroxypropoxyl (mm /s) group group NE-100 22.50% 8.60% 114 SE-50 28.60% 8.50% 47.9 SFE-400 27.90% 6.00% 408 MCE-100 29.40% - 102 NE-4000 22.90% 9.50% 5210 The holding times were measured for Examples 4, 7 and 8 and Comparative Example 2. The results are shown in Table 5 below and In the vertical axis represents the holding time in minutes and seconds.

[Table 5] Table 5 Comparative Example 4 Example 7 Example 8 Example 2 Holding time 13'11'' 18'43'' 19'35'' 08'24'' Standard deviation 02'25'' 02'24'' 01'58'' 04'03'' Table 5 and show that Examples 4, 7 and 8 were improved in holding times as compared to Comparative Example 2 having methylcellulose only containing methoxy group, not containing hydroxypropoxyl group. Comparison between Examples 4 and 7 shows that a longer holding time was obtained in Example 7 that contains the HPMC having a high degree of substitution of methoxy group if they are substantially the same in the substitution degree of hydroxypropoxyl group. (3) Relation between Viscosity of HPMC and Holding Time The relation between an HPMC content and the holding time was studied.

[Example 9] A soft ice cream of Example 9 was produced in the same manner as in Example 4 except that METOLOSE "NE-4000" (commercially available from Shin-Etsu Chemical Co., Ltd.) was used as the HPMC. The HPMC content was 0.10% by weight.

The holding times for Examples 4 and 9 were measured. The results are shown in Table 6 below and In the vertical axis represents the holding time in minutes and seconds.

[Table 6] Table 6 Example 4 Example 9 Holding time 12'07'' 13'06'' Standard deviation 02'52'' 04'58'' Table 6 and show that Example 9 having high viscosity in the HPMC has a longer holding time as compared to Example 4. (4) Relation between the Number of Heat Sterilization Processes of HPMC by Frozen Dessert Production Apparatus and Holding Time The relation between the number of heat sterilization processes of HPMC by the frozen dessert production apparatus and the holding time was studied. For the soft ice cream of Example 4 having an HPMC content of 0.10% by weight, holding times were measured when zero times of the sterilization processes, one time of the sterilization process, and seven times of the sterilization processes were performed. The results are shown in Table 7 below and In the vertical axis represents the holding time in minutes and seconds.

[Table 7] Table 7 Number of sterilization processes by frozen dessert 0 time 1 time 7 times production apparatus Holding time 12'07'' 13'06'' 06'59'' Standard deviation 02'52' 04'58'' 03'29'' Table 7 and show that while the holding time is shortened as the number of sterilization processes increases, a holding time long enough to eat can be obtained even in the case of seven times of sterilization processes. 2. Soft Ice Cream of Ice Cream Standard (1) Relation between HPMC Content and Holding Time The relation between the HPMC content and the holding time was studied. The compositions of a soft ice cream mix base of the ice cream standard are as follows.

[Soft Ice Cream Mix Base of Ice Cream Standard] Sugars, dairy products, emulsifiers, stabilizers and other components such as water were used as raw materials to prepare a soft ice cream mix base of the ice cream standard in Comparative Example 3 to be described below at the ratios of the raw materials shown in Table 8. Sugar, etc. were used as the sugars, butter and skim milk powder were used as the dairy products, cellulose, casein Na and thickening polysaccharides were used as the stabilizers, and a caroten pigment, etc. were used as the other components.

[Table 8] Table 8 Component % by weight Sugar 13.2 Dairy product 20.0 Emulsifier 0.7 Stabilizer 0.4 Other component 0.1 Water 65.6 Sum 100.0 Milk fat content 8.0 Milk solid content 18.1 [Example 10] As the HPMC, METOLOSE "NE-100" commercially available from Shin-Etsu Chemical Co., Ltd. was used. A soft ice cream mix of the ice cream standard in Example 10 was prepared by mixing the component material of the soft ice cream mix base of the ice cream standard described above with the HPMC so that the HPMC content would be 0.03% by weight. In the same manner as Example 1, the soft ice cream of the ice cream standard in Example was thus produced. More specifically, the preparation was made such that the amount of the sugars to be added was subtracted by the corresponding amount of the added HPMC with respect to the ratios of the raw materials shown in Table 8 described above.

[Examples 11 and 12] Soft ice creams of Examples 11 and 12 were produced in the same manner as in Example 10 except that the component materials of the soft ice cream mix base were mixed with the HPMC so that the HPMC content would be 0.10% by weight and 0.50% by weight, respectively.

[Comparative Example 3] A soft ice cream of Comparative Example 3 was produced in the same manner as Example 10 except that no HPMC was included.

In the same manner as Example 1, the time periods until the soft ice creams of Example 10-12 and Comparative Example 3 start to melt and fall were measured. The results are shown in Table 9 below and In the horizontal axis of the graph represents the HPMC content (wt%) while the vertical axis thereof represents the holding time (in seconds).

[Table 9] Table 9 Comparative Example 10 Example 11 Example 12 Example 3 NE-100 0.03% 0.10% 0.50% 0.00% Holding time 02'08'' 02'53'' 04'31'' 02'06'' Standard deviation 00'22'' 00'26'' 00'49'' 00'18'' Table 9 and show that Examples 10-12 containing the HPMC are improved in the holding times as compared to Comparative Example 3 not containing HPMC. It is preferable that the HPMC content is from 0.03% by weight to 0.50% by weight.

The lower limit of the HPMC content is preferably 0.05% by weight, while the upper limit of the HPMC content is preferably 0.40% by weight, more preferably 0.30% by weight, and even more preferably 0.25% by weight. (2) Relation between Holding Time and Substitution Degree of Methoxy Group and Substitution Degree of Hydroxypropoxyl Group of HPMC The relation between the substitution degree of methoxy group and the substitution degree of hydroxypropoxyl group of HPMC and the holding time was studied.

[Examples 13 and 14] Soft ice creams of Examples 13 and 14 were produced in the same manner as in Example 11 except that METOLOSE "SE-50" and "SFE-400" (commercially available from Shin-Etsu Chemical Co., Ltd.) were used as the HPMC. The HPMC content was 0.10% by weight.

[Comparative Example 4] A soft ice cream of Comparative Example 4 was produced in the same manner as in Example 11 except that methylcellulose ("MCE- 100" commercially available from Shin-Etsu Chemical Co., Ltd.) was used in place of HPMC.

The holding times were measured for Examples 11, 13, 14 and Comparative Examples 3 and 4. The results are shown in Table 10 below and In the vertical axis represents the holding time in minutes and seconds.

[Table 10] Table 10 Example Example Example Comparative Comparative 11 13 14 Example 4 Example 3 Holding time 02'53'' 12'27'' 04'07'' 02'36'' 02'06'' Standard 00'26'' 02'02'' 01'12'' 00'36'' 00'18'' deviation Table 10 and show that Examples 11, 13, 14 and Comparative Example 4 are improved in the holding times as compared to Comparative Example 3 not containing HPMC.

Examples 11, 13 and 14 are improved in the holding times as compared to Comparative Example 4 having methylcellulose only containing methoxy group, not containing hydroxypropoxyl group.

Comparison between Examples 11 and 13 shows that a longer holding time was obtained in Example 13 that contains the HPMC having a high degree of substitution of methoxy group if they are substantially the same in the substitution degree of hydroxypropoxyl group. Comparison between Examples 13 and 14 shows that a longer holding time was obtained in Example 13 that contains the HPMC having a high degree of substitution of hydroxypropoxyl group if they are substantially the same in the substitution degree of methoxy group. 3. Hard Ice Cream of Ice Cream Standard (1) Relation between HPMC Content and Holding Time The relation between a HPMC content and the holding time was studied.

[Example 15] A hard ice cream mix (ice cream standard) of Example 15 was prepared by mixing the component material of the mix base (ice cream standard) shown in Table 8 with METOLOSE "SE-50" commercially available from Shin-Etsu Chemical Co., Ltd. used as HPMC so that the HPMC content would be 0.10% by weight.

Subsequently, the hard ice cream mix of Example 15 was put in a frozen dessert production apparatus (freezer NA6462WE, produced by Nissei Co., Ltd.) and frozen. Approximately 110 g (approximately 140 ml) of the ice cream was taken out and served in a cone cup (No. 15 cone, produced by Nissei Co., Ltd.) by twisting upward the ice cream three and a half turns, and then soon put in a freezer at -20°C. The ice cream was left in the freezer for 24 hours or longer to be hardened. Thus, the hard ice cream (ice cream standard) of Example 15 was produced. The product temperature after the hardening was approximately -20°C.

[Comparative Example 5] A soft ice cream of Comparative Example 5 was produced in the same manner as Example 15 except that no HPMC was included.

In the same manner as Example 1, the holding times were measured for the hard ice creams of Example 15 and Comparative Example 5. The results are shown in Table 11 below and In the vertical axis represents the holding time in minutes and seconds.

[Table 11] Table 11 Comparative Example 15 Example 5 Holding time 28'28'' 07'15'' Standard deviation 02'21'' 00'49'' Table 11 and show that Example 15 containing the HPMC is improved in the holding times as compared to Comparative Example 5 not containing HPMC. 4. Relation between Amount of Fat in Soft Ice Cream Mix and Holding Time Holding times were measured by varying the amounts of fat in the soft ice cream mix base shown in Table 1.

[Comparative Example 6] A soft ice cream of Comparative Example 6 was produced in the same manner as Example 1 except that the amount of fat in the soft ice cream mix base is 0% by weight and no HPMC was included.

Note that the preparation was made such that the amount of sugars to be added was added by the corresponding amount of 0% by weight of the fat amount with respect to the ratios of the raw materials shown in Table 1 described above.

[Comparative Example 7] A Soft ice cream of Comparative Example 7 was produced in the same manner as in Comparative Example 6 except that METOLOSE "NE-100" commercially available from Shin-Etsu Chemical Co., Ltd. was used as the HPMC, and that the HPMC content was 0.10% by weight. Note that the preparation was made such that the amount of the sugars to be added was subtracted by the corresponding amount of the added HPMC with respect to the ratios of the raw materials shown in Table 6 described above.

[Comparative Example 8] A soft ice cream of Comparative Example 8 was produced in the same manner as Comparative Example 6 except that the amount of fat in the soft ice cream mix base was 3.0% by weight.

[Example 16] A soft ice cream of Example 16 was produced in the same manner as Comparative Example 8 except that the HPMC content is 0.10% by weight.

A comparative example in which the amount of fat in the soft ice cream mix base was 6.0% by weight and no HPMC was included corresponds to Comparative Example 1, while an example in which the amount of fat in the soft ice cream mix base was 6.0% by weight and the HPMC content was 0.10% by weight corresponds to Example 4.

[Comparative Example 9] A soft ice cream of Comparative Example 9 was produced in the same manner as Comparative Example 6 except that the amount of fat in the soft ice cream mix base was 9.0% by weight.

[Example 17] A soft ice cream of Example 17 was produced in the same manner as Comparative Example 10 except that the HPMC content was 0.10% by weight.

[Comparative Example 10] A soft ice cream of Comparative Example 10 was produced in the same manner as Comparative Example 6 except that the amount of fat in the soft ice cream mix base is 15.0% by weight.

[Example 18] A soft ice cream of Example 18 was produced in the same manner as Comparative Example 11 except that the HPMC content was 0.10% by weight.

Similarly to Example 1, the holding times of the soft ice cream were measured for Examples 4 and 16-18, and Comparative Example 1 and 6-10. The results are shown in Table 12 below, and FIGs. 9 and 10. In the horizontal axis represents the fat content (wt%) while the vertical axis represents the holding time (seconds). shows the results of Comparative Example 7 and Examples 4 and 16-18. is a graph showing the holding times of the soft ice creams in Examples 4 and 16-18, and Comparative Examples 1 and 6-10. In , the horizontal axis represents the fat content (wt%) while the vertical axis represents the holding time (minutes and seconds).

[Table 12] Table 12, and show that HPMC inclusion improves the holding time if the fat content is equal to or more than Table 12 Fat content (%) 0 3.0 6.0 9.0 15.0 Compar- Compar- Compar- Compar- Compar- Compar- ative ative ative Example ative Example ative Example ative Example Example Example Example 16 Example 4 Example 17 Example 18 6 7 8 1 9 10 Holding time 02'21'' 01'58'' 02'30'' 02'53'' 03'12'' 15'44'' 08'05'' 18'52'' 18'41'' 21'51'' Standard 00'32'' 00'26'' 00'19'' 00'33'' 00'54'' 03'58'' 04'06'' 03'18'' 07'06'' 04'56'' deviation 3% by weight. The lower limit of the fat content is preferably 4% by weight, more preferably 5% by weight.

It is confirmed that an ice cream mix base having an HPMC content of 0.01% by weight to 0.50% by weight can favorably extend the holding time while the pleasant viscosity, flavor and texture are maintained. An extended holding time can be obtained if the fat content is from 3% by weight to 15% by weight.

It is to be understood that the embodiments disclosed here is illustrative in all respects and not restrictive. The scope of the present invention is defined by the appended claims, and all changes that fall within the meanings and the bounds of the claims, or equivalence of such meanings and bounds are intended to be embraced by the claims.

Claims (4)

1. A frozen dessert containing hydroxypropyl methylcellulose, wherein a substitution degree of a methoxy group of the hydroxypropyl methylcellulose is from 19% to 30%, and a substitution degree of a hydroxypropoxyl group of the hydroxypropyl methylcellulose is from 4% to 12%; wherein a content of the hydroxypropyl methylcellulose is from 0.01% by weight to 0.5% by weight; wherein a fat content is 3% by weight or more; wherein a time period from when the frozen dessert is put in an incubator maintained at 35°C and having circulated air inside to when the frozen dessert melts and falls is 130 seconds or more; wherein the frozen dessert is ice cream; wherein the frozen dessert contains a dairy product; and provided that the frozen dessert does not contain fermented milk.

2. The frozen dessert according to claim 1, wherein the ice cream is a soft ice cream.

3. A frozen dessert raw material when used to prepare ice cream containing hydroxypropyl methylcellulose, wherein a substitution degree of a methoxy group of the hydroxypropyl methylcellulose is from 19% to 30%, and a substitution degree of a hydroxypropoxyl group of the hydroxypropyl methylcellulose is from 4% to 12%; wherein a content of the hydroxypropyl methylcellulose is from 0.01% by weight to 0.5% by weight; wherein a fat content is 3% by weight or more: wherein the ice cream contains a dairy product; provided that the ice cream does not contain fermented milk; and wherein a time period from when the ice cream is put in an incubator maintained at 35°C and having circulated air inside to when the ice cream melts and falls is 130 seconds or more.

4. A production method for ice cream using the frozen dessert raw material according to claim 3. FIG.1 SOFT ICE CREAM HARD ICE CREAM (ICE CREAM TYPE) (ICE CREAM TYPE) RAW MATERIAL RAW MATERIAL BLENDING BLENDING STERILIZATION STERILIZATION (OR HOMOGENIZATION) (OR HOMOGENIZATION) HOMOGENIZATION STERILIZATION (OR STERILIZATION) (OR HOMOGENIZATION) COOLING COOLING AGING MANUFACTURING FACTORY FREEZING FILLING FILLING HARDENING (OR PACKAGING) PACKAGING (OR HARDENING) PACKING IN BOX PACKING IN BOX STORAGE UNDER ROOM STORAGE UNDER TEMPERATURE FREEZING (OR UNDER REFRIGERATION) DISTRIBUTION DISTRIBUTION UNDER UNDER ROOM TEMPERATURE FREEZING (OR UNDER REFRIGERATION) FREEZING SELLING DISPLAY UNDER STORE FREEZING SALE SALE FIG.2 0.00 0.10 0.20 0.30 0.40 0.50 0.60 CONTENT FIG.3 24'00'' 22'00'' 20'00'' 18'00'' 16'00'' 14'00'' 12'00'' 10'00'' 08'00'' 06'00'' 04'00'' 02'00'' 00'00'' EXAMPLE 4 EXAMPLE 7 EXAMPLE 8 COMPARATIVE EXAMPLE 2 FIG.4 20'00'' 18'00'' 16'00'' 14'00'' 12'00'' TIME 10'00'' 08'00'' 06'00'' 04'00'' 02'00'' 00'00'' EXAMPLE 4 EXAMPLE 9 FIG.5 20'00'' 18'00'' 16'00'' 14'00'' 12'00'' TIME 10'00'' 08'00'' 06'00'' 04'00'' 02'00'' 00'00'' 0 TIME 1 TIME 7 TIMES NUMBER OF STERILIZATION PROCESSES BY FROZEN DESSERT PRODUCTION APPARATUS FIG.6 0.00 0.10 0.20 0.30 0.40 0.50 0.60 CONTENT FIG.7 16'00'' 14'00'' 12'00'' 10'00'' 08'00'' 06'00'' 04'00'' 02'00'' 00'00'' COMPARATIVE EXAMPLE EXAMPLE EXAMPLE COMPARATIVE EXAMPLE 11 13 14 EXAMPLE FIG.8 35'00'' 30'00'' 25'00'' 20'00'' 15'00'' 10'00'' 05'00'' 00'00'' COMPARATIVE EXAMPLE 15 EXAMPLE 5 FIG.9 FAT CONTENT EXAMPLE 18 COMPARATIVE EXAMPLE 10 EXAMPLE 17 COMPARATIVE EXAMPLE 9 EXAMPLE 4 COMPARATIVE EXAMPLE 1 EXAMPLE 16 COMPARATIVE EXAMPLE 8 COMPARATIVE EXAMPLE 7 COMPARATIVE EXAMPLE 6 FIG.10 30'00" 28'00" 26'00" 24'00" 22'00" 20'00" 18'00" 16'00" 14'00" 12'00" 10'00" 08'00" 06'00" 04'00" 02'00" 00'00" 0% 3.0% 6.0% 9.0% 15.0% FAT CONTENT