Strawberries with increased aromatic compounds and method for producing the same

Abstract

The present invention provides strawberries with increased aromatic compounds and a method for producing the same. [Solution] The strawberries of the present invention contain ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate as aroma components, and the total content of the aroma components is 1150 ppb or more and 14100 ppb or less.

Description

Technical Field

[0001] The present invention relates to strawberries with an increased amount of aroma components and a method for producing the same.

Background Art

[0002] Patent Document 1 describes frozen strawberries having a predetermined breaking load and breaking strain rate. Non-Patent Document 1 reports that by storing strawberries in a CO2 atmosphere and then storing them in air at 0°C, the hardness of the strawberries can be maintained and the generation of off-flavors can be suppressed. Also, Non-Patent Document 2 reports that the respiration of strawberries is suppressed by storing wild strawberries in an atmosphere of a certain ratio of CO2 and O2.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Non-Patent Documents

[0004]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

[0005] One aspect of the present invention aims to provide strawberries with increased aromatic components and a method for producing the same. [Means for solving the problem]

[0006] The inventors diligently conducted research to achieve the above objective. As a result, they discovered that the total content of the aroma components ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate can be increased by storing strawberries under predetermined conditions, thus completing the present invention.

[0007] In other words, the present invention is (1) Strawberries with increased aroma components, containing ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate as aroma components, with a total content of the aroma components being 1150 ppb or more and 14100 ppb or less. (2) Strawberries having an increased amount of the aroma components described in (1), wherein the total content of ethyl 2-methylbutyrate and ethyl isovalerate is 14 ppb or more and 1000 ppb or less. (3) Strawberries having an increased amount of the aroma components described in (1) or (2), wherein the ratio of the sum of the content of ethyl 2-methylbutyrate and ethyl isovalerate to the sum of the content of ethyl acetate, ethyl butyrate and ethyl hexanoate is 1:4 or more and 1:81 or less. (4) A method for producing strawberries with increased aromatic components, comprising the step of placing strawberries in a sealed container and storing them at a temperature of 0°C or higher and 20°C or lower for 8 hours or more and 72 hours or less, wherein the volume ratio of the container to the volume of the strawberries is greater than 1 and 10 or less. [Effects of the Invention]

[0008] According to one aspect of the present invention, strawberries with increased aromatic components can be provided. [Modes for carrying out the invention]

[0009] <Features of the Invention> Strawberries with increased aroma components according to one aspect of the present invention (hereinafter referred to as "strawberries according to one aspect of the present invention") contain ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate as aroma components, with a total aroma component content of 1150 ppb or more and 14100 ppb or less. The total aroma component content can be increased to 1150 ppb or more by the method for producing strawberries according to one aspect of the present invention, which will be described later.

[0010] Furthermore, a further effect is obtained in which the strawberries have superior flavor when the total content of aroma components is between 1150 ppb and 14100 ppb. For example, in a strawberry according to one aspect of the present invention, multiple components that exhibit the fruity aroma of strawberries are contained in appropriate amounts. Therefore, a flavorful strawberry can be provided according to one aspect of the present invention. In this specification, "flavor" means aroma and taste.

[0011] <Strawberry varieties> The strawberries according to one aspect of the present invention may be of any type. For example, Yume Tsuzuki, Yume Tsuzuki No. 2, Hoko Wase, Saga Honoka, Nyoho, Toyonoka, Akihime, Raiho, Red Pearl, Asuka Wave, Akane Musume, Echigo Hime, Tochiotome, Asuka Ruby, Sachinoka, Tochihime, Amaterasu, Fukuoka S6 (Amaou), Beni Hoppe, Summer Princess, HS138 (Natsumi), Natsu Musume (Kareinya), Yayoi Hime, Pechika, Kaorino (registered trademark), Wada Hatsukoi, Sakura Momo Ichigo, Chiba S4, Diamond Berry, Albion, Monterey, Sakihime, Oita No. 6, etc.

[0012] <Total content of aroma components in strawberries> A strawberry according to one aspect of the present invention contains ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate as aroma components, and the total content of these aroma components (hereinafter sometimes simply referred to as "total aroma component content") is between 1150 ppb and 14100 ppb. In a strawberry according to one aspect of the present invention, a total aroma component content of 1150 ppb or more enhances the fruity aroma of the strawberry, resulting in an excellent flavor. In a strawberry according to one aspect of the present invention, a total aroma component content of 14100 ppb or less results in a good fresh aroma of the strawberry, resulting in an excellent flavor. Off-flavors become noticeable above 14100 ppb. The aroma components of strawberries can be measured using measurement methods commonly used in the art, for example, by using GC-MS.

[0013] <Ethyl acetate> Ethyl acetate is an aromatic compound that exhibits pineapple and banana-like scents. As the amount of ethyl acetate increases, the fruity aroma intensifies. In the total amount of strawberry aromatic compounds in the present invention, it is preferable that the amount be 300 ppb or more. On the other hand, at high concentrations, it behaves as an off-flavor, sometimes referred to as a thinner-like odor, so it is preferable that the amount be 10,000 ppb or less in order to maintain a good aroma.

[0014] <Ethyl butyrate> Ethyl butyrate, like ethyl acetate, is an aroma component that exhibits pineapple and banana-like scents. Increasing the amount of ethyl butyrate enhances the fruity aroma. In one embodiment of the present invention, the ethyl butyrate content is preferably 200 ppb or more within the range of the total aroma component content of the strawberry according to one embodiment of the present invention. On the other hand, at high concentrations, it behaves as an off-flavor, sometimes referred to as an ether-like odor, so it is preferable to keep it at 4,000 ppb or less in order to maintain a good aroma.

[0015] <2-methylbutyrate ethyl> Ethyl 2-methylbutyrate exhibits a sweet and flowery fruity aroma. As the amount of ethyl 2-methylbutyrate increases, the fruity aroma intensifies. In the strawberry which is one aspect of the present invention, the content of ethyl 2-methylbutyrate is preferably 1 ppb or more within the range of the total content of the aroma components of the strawberry in the present invention. Since an artificial aroma is felt in the high concentration range, it is preferably 900 ppb or less.

[0016] <Ethyl isovalerate> Ethyl isovalerate is an aroma component that exhibits a sweet aroma similar to grapes and apples. As the amount of ethyl isovalerate increases, the fruity aroma intensifies. In the strawberry which is one aspect of the present invention, the content of ethyl isovalerate is preferably 1 ppb or more within the range of the total content of the aroma components of the strawberry in the present invention. Since an artificial aroma is felt in the high concentration range, it is preferably 500 ppb or less.

[0017] <Ethyl hexanoate> Ethyl hexanoate is an aroma component that exhibits a flowery aroma peculiar to strawberries. As the amount of ethyl hexanoate increases, the fruity aroma intensifies. In the strawberry which is one aspect of the present invention, the content of ethyl hexanoate is preferably 10 ppb or more within the range of the total content of the aroma components of the strawberry in the present invention. Since a fermented odor or an artificial aroma is felt in the high concentration range, it is preferably 2,200 ppb or less.

[0018] <Sum of the contents of ethyl 2-methylbutyrate and ethyl isovalerate in strawberry> Furthermore, in the strawberry according to one aspect of the present invention, the sum of the contents of ethyl 2-methylbutyrate and ethyl isovalerate is preferably 14 ppb or more, more preferably 20 ppb or more, and even more preferably 30 ppb or more from the viewpoint of the fruity aroma of the strawberry. Also, since an artificial aroma is felt in the high concentration range, it is preferably 1000 ppb or less, and more preferably 600 ppb or less.

[0019] <Aroma component content ratio of strawberry> Furthermore, for the strawberry according to one embodiment of the present invention, the ratio of the sum of the contents of ethyl 2-methylbutyrate and ethyl isovalerate to the sum of the contents of ethyl acetate, ethyl butyrate and ethyl hexanoate is preferably 1:4 or more and 1:81 or less. From the viewpoint of imparting a more fruity aroma, 1:40 or less is preferable.

[0020] <Use of strawberry according to one embodiment of the present invention> The strawberry according to one embodiment of the present invention may be eaten as it is or used as a raw material for processed foods. Since the strawberry according to one embodiment of the present invention has an increased amount of aroma components, a large amount of aroma components remain even after processing. Thereby, the flavor in processed foods can be further improved. In order to obtain a desired flavor for the processed food, the amount of the strawberry according to one embodiment of the present invention may be appropriately increased or decreased. In addition, the strawberry according to one embodiment of the present invention may be stored frozen. The frozen strawberry also contains a large amount of aroma components. Examples of the freezing method include IQF (Individual Quick Frozen) and BQF (Block Quick Freezing).

[0021] <Method for producing strawberry according to the present invention> A method for producing a strawberry with an increased amount of aroma components according to one embodiment of the present invention (hereinafter referred to as "the production method according to one embodiment of the present invention") includes a step of storing strawberries in a sealed container at a temperature of 0°C or higher and 20°C or lower for 8 hours or longer and 72 hours or shorter (hereinafter, the storage step is referred to as the "storage step"), and the volume ratio of the container is greater than 1 and 10 or less with respect to the volume of the strawberries. By the production method according to one embodiment of the present invention, strawberries with an excellent flavor containing a well-balanced aroma derived from ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate and ethyl hexanoate are produced.

[0022] <Strawberry> The form of strawberries used in the strawberry manufacturing method according to one aspect of the present invention is not particularly limited, but examples include fresh strawberries and frozen strawberries. Fresh strawberries refer to strawberries that have not been frozen or dried after harvesting. As a pretreatment, sterilization by conventionally known methods, washing of fresh strawberries, and removal of stems may be performed. It is preferable to perform similar pretreatment in the case of frozen strawberries.

[0023] <Storage process> The storage step in a manufacturing method according to one aspect of the present invention involves placing strawberries in a sealed container and storing them at a temperature of 0°C or higher, 20°C or lower, for 8 hours or more and 72 hours or less. By using a container with a volume described later, the amount of aroma components in the strawberries can be increased. The inventors of this invention hypothesize that this is due to metabolic activity initiated by the respiration of the strawberries. In other words, the inventors of this application have found that respiration increases the CO2 concentration and decreases the O2 concentration inside the container, changing the environment inside the container, thereby restricting the respiration of the strawberries and increasing the amount of aroma components. Furthermore, they have determined the appropriate container volume to maximize the effect of environmental changes due to respiration on the increase in aroma components, and have succeeded in increasing the amount of aroma components even in a short period of time of 72 hours or less.

[0024] <Container> In one embodiment of the present invention, the volume ratio of the container used in the storage process is greater than 1 and 10 or less relative to the volume of the strawberries. The presence of air in addition to the strawberries in the container allows for a suitable increase in the aroma components of the strawberries. Furthermore, from the viewpoint of ensuring a sufficient amount of oxygen necessary for the strawberries to respire, the volume ratio of the container is preferably 1.05 or more, more preferably 1.1 or more, and even more preferably 2.0 or more relative to the volume of the strawberries. From the viewpoint of potentially causing environmental changes through respiration, it is preferably 10 or less. The volume of the container refers to the volume of the internal space including the volume of the strawberries.

[0025] Furthermore, the container's structure only needs to be capable of sealing. It may also be equipped with refrigeration equipment to maintain a constant temperature inside the container. Additionally, it may be equipped with devices to control the composition of gases such as CO2 to manage the CO2 concentration inside the container.

[0026] <Storage temperature> In the storage process, the temperature at which strawberries are stored should be 0°C or higher, preferably 2°C or higher, from the viewpoint of promoting respiration, and 20°C or lower, preferably 15°C or lower, from the viewpoint of maintaining the freshness of the strawberries and preventing the growth of bacteria.

[0027] <Storage time> In the storage process, the storage time for strawberries is 8 hours or more, more preferably 10 hours or more, and even more preferably 12 hours or more, from the viewpoint of further increasing the amount of aromatic components. Furthermore, from the viewpoint of maintaining the freshness of the strawberries and preventing the growth of bacteria, the storage time is 72 hours or less, more preferably 48 hours or less, and even more preferably 24 hours or less.

[0028] <Carbon dioxide concentration> In addition to the container volume, storage temperature, and storage time mentioned above, the storage process may also be controlled based on the CO2 concentration inside the container to restrict the respiration of the strawberries. For example, from the viewpoint of increasing the amount of aroma components, it is preferable to store the product at a concentration of 1.5% or more, and more preferably at a concentration of 2.5% or more. Furthermore, from the viewpoint of preventing flavor deterioration due to excessive increases in the concentration of ethyl acetate, etc., it is preferable to store the product at a concentration of 15% or less, and more preferably at a concentration of 10% or less.

[0029] The present invention will be described in detail below based on examples and comparative examples. However, the present invention is not limited to these. [Examples]

[0030] An embodiment of the present invention is described below. In this embodiment, the aroma components and sensory evaluation of strawberries stored under the following conditions were performed.

[0031] [Examples 1-19, Comparative Examples 1-16] <Making strawberries> 250g (0.26L) or 1200g (12.6L) of harvested strawberry samples were placed in pouches (Meiwa Pax, Barrier NY15 / Dry / LLD#60) or pails (21.875L) of the volumes shown in Tables 1 to 4, sealed, and stored at the temperatures and times shown in each table. Five varieties of strawberries were used: Yume Tsuzuki, Yume Tsuzuki No. 2, Beni Hoppe, Monterey, and Hokou Wase.

[0032] <Measurement of aroma components> Aroma components were measured for strawberries stored under the conditions shown in Tables 1-4 below. Some strawberries were frozen using IQF or BQF until measurement, and then thawed. Examples marked "raw" in Tables 1-4 are examples where aroma components were measured after storage without further freezing.

[0033] The aroma components were measured using the following method. First, 20 mL of PorapakQ (ethyl vinylbenzene-divinylbenzene copolymer, 50-80 meah, Waters) was packed into a filtered glass column (φ2 cm × 20 cm) as an aroma component extraction and concentration column, and washed in that order with diethyl ether, methanol, and pure water. Next, the sample was homogenized, 50 g was weighed out, 50 mL of pure water was added, and the supernatant was obtained by centrifugation. Another 50 mL of pure water was added to the residue, and centrifugation was performed to obtain the supernatant. An internal standard substance (100 ppm cyclohexanol) was added to the combined supernatant, and the solution was passed through the aforementioned column (20 mL), washed with pure water, and the aroma components were eluted from the column with ether. This eluate was dehydrated, concentrated, and injected into a gas chromatograph-mass spectrometer (Shimadzu Corporation, GCMS QP 2020NX) for analysis. The analytical conditions are shown below. (GC conditions) Column: DB-Wax UI capillary column (J&W), 60m x 0.25mm id x 0.25μm film thickness Column temperature: Initial temperature 40°C, held for 10 minutes, then increased temperature to 220°C at a rate of 3.0°C / min and held for 15 minutes, then increased temperature to 245°C at a rate of 10.0°C / min and held for 20 minutes. Evaporation chamber temperature: 230℃ Injection mode: Split; Split ratio 1:5 Carrier gas: He Column inlet pressure: 185kPa Linear speed: 34.2cm / s Purge flow rate: 3 ml / min Injection volume: 1.0μl MS conditions Ion source temperature: 200℃ Interface temperature: 230℃ Detector gain voltage: 1.05kV Scan MS: m / z: 29-350

[0034] For analysis and interpretation, LabSolutions-GCMSsolution version 2.72 (Shimadzu Corporation) was used. In this case, the identification of volatile compounds was performed by comparing the mass spectrum of a component at a specific retention time obtained by gas chromatography-mass spectrometry with the mass spectrum similarly obtained using a standard, and the mass spectrum of the published library WILEY7, and comparing the Kovats Index of the peak in question with the Kovats Index of the standard.

[0035] Furthermore, in identifying and quantifying volatile components, the total ion area was not used. Instead, the target ion, reference ion, and their relative ratio were used for identification. The total ion area was then calculated using the target ion area as the ratio of the target ion to the total ions of the substance in question in the published library WILEY7, and quantitative calculations were performed. The same calculation was performed for the internal standard cyclohexanol, and the concentration of the substance was expressed as the relative concentration (ppb) with respect to the internal standard cyclohexanol.

[0036] <Sensory evaluation of fragrance> Simultaneously, a sensory evaluation of the strawberry aroma obtained in the examples and comparative examples was conducted. The evaluation was performed by a panel of five trained individuals who assessed the strawberry aroma. The degree to which the strawberry aroma (flavor) was perceived as good was expressed on a scale of 1 to 4, with 4 being the highest score and 1 the lowest score.

[0037] [Criteria for evaluating fragrance] 4: The fruity and sweet aromas characteristic of strawberries are well-balanced. 3: You can smell the fruity and sweet aroma characteristic of strawberries. 2: A slight fruity and sweet aroma characteristic of strawberries can be detected. 1: It barely has the fruity or sweet aroma characteristic of strawberries.

[0038] [Table 1]

[0039] [Table 2]

[0040] [Table 3]

[0041] [Table 4]

[0042] <Result> As shown in Tables 1 to 4, it was demonstrated that strawberries with increased aroma components can be produced by a process that includes storing strawberries in a sealed container at a temperature of 0°C or higher and 20°C or lower for 8 hours or more and 72 hours or less, with the volume ratio of the container being greater than 1 and 10 or less relative to the volume of the strawberries. Specifically, it was demonstrated that strawberries with increased aroma components can be provided that contain ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate, with a total aroma component content of 1150 ppb or more and 14100 ppb or less. Furthermore, it was demonstrated that such strawberries have superior flavor.

[0043] Furthermore, among these five aroma components, strawberries with a total content (two-component content) of ethyl 2-methylbutyrate and ethyl isovalerate of 20 ppb or more and 1000 ppb or less received the highest score of 4 in the sensory evaluation of aroma, and were considered to have the best strawberry flavor.

[0044] Furthermore, among the ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate contained in the strawberries according to the present invention, strawberries (Examples 1 to 18) in which the ratio of the sum of the contents of ethyl 2-methylbutyrate and ethyl isovalerate to the sum of the contents of ethyl acetate, ethyl butyrate, and ethyl hexanoate was 1:4 or more and 1:81 or less had superior flavor. [Industrial applicability]

[0045] This invention can be used for fresh consumption and for processed foods made from fresh strawberries.

Claims

1. A strawberry with increased aroma components, comprising ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate, wherein the total content of the aroma components is 1150 ppb or more and 14100 ppb or less.

2. A strawberry with increased aroma components according to claim 1, wherein the total content of ethyl 2-methylbutyrate and ethyl isovalerate is 14 ppb or more and 1000 ppb or less.

3. A strawberry with increased aroma components according to claim 1 or 2, wherein the ratio of the sum of the contents of ethyl 2-methylbutyrate and ethyl isovalerate to the sum of the contents of ethyl acetate, ethyl butyrate and ethyl hexanoate is 1:4 or more and 1:81 or less.

4. The process includes placing strawberries in a sealed container and storing them at a temperature of 0°C or higher and 20°C or lower for 8 hours or more and 72 hours or less. A method for producing strawberries with increased aromatic components, wherein the volume ratio of the container is greater than 1 and less than or equal to 10 of the volume of the strawberries.

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