Strawberries with increased aromatic content and their manufacturing method

Abstract

To provide strawberries having an increased amount of aroma components and a method for producing the same. [Solution] The strawberry of the present invention contains, as aroma components, ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate and ethyl hexanoate, 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 having increased amounts of aromatic components and a method for producing the same. [Background technology]

[0002] Patent Document 1 describes frozen strawberries having a predetermined breaking load and breaking strain rate. Non-Patent Document 1 reports that storing strawberries in a CO2 atmosphere and then storing them in air at 0°C can maintain the firmness of the strawberries and suppress the generation of off-flavors. Non-Patent Document 2 reports that storing wild strawberries in an atmosphere of CO2 and O2 at a constant ratio suppresses the respiration of the strawberries. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6688419 [Non-patent literature]

[0004] [Non-Patent Document 1] Firmness and Aroma Composition of Strawberries following Short-term High Carbon Dioxide Treatments, Mette Larsen et.al., HortScience 30(2) 303-305, 1995 [Non-Patent Document 2] Controlled Atmosphere Storage of Wildstrawberry Fruit (Fragaria vesca L.), Eva Almenar et.al., Journal of Agricultural and Food Chemistry, 54, 1, 86-91, 2006 Summary of the Invention [Problem to be solved by the invention]

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

[0006] The present inventors have conducted extensive research to achieve the above object, and as a result have found that the total content of aroma components, ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate, can be increased by storing strawberries under specific conditions, thereby completing the present invention.

[0007] That is, the present invention provides: (1) A strawberry having an increased amount of aroma components, which contains, as aroma components, ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate, and the total content of said aroma components is 1150 ppb or more and 14100 ppb or less; (2) A strawberry having an increased amount of the aroma components described in (1), in which the total content of ethyl 2-methylbutyrate and ethyl isovalerate is 14 ppb or more and 1000 ppb or less. (3) A strawberry having an increased amount of aroma components according to (1) or (2), 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 is 1:4 or more and 1:81 or less. (4) A method for producing strawberries with increased aromatic components, comprising the steps 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, wherein the volume ratio of the container to the volume of the strawberries is greater than 1 and less than 10. Effect of the Invention

[0008] According to one aspect of the present invention, strawberries with increased amounts of aromatic components can be provided. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0010] In addition, a further effect of producing strawberries with excellent flavor can be obtained by having a total content of aroma components of 1150 ppb or more and 14100 ppb or less. For example, in the strawberries according to one embodiment of the present invention, a plurality of components exhibiting the fruity aroma of strawberries are contained in moderate amounts. Thus, strawberries with rich flavor can be provided according to one embodiment of the present invention. In this specification, "flavor" means aroma and taste.

[0011] <Strawberry varieties> The strawberry according to one embodiment of the present invention may be any variety, such as Yume Tsuzuki, Yume Tsuzuki 2, Takara Kou Wase, Saga Honoka, Meiho, Toyonoka, Akihime, Raiho, Red Pearl, Asuka Wave, Akane-ko, Echigo Hime, Tochiotome, Asukarubee, Sachinoka, Tochihime, Amaterasu, Fukuoka S6 (Amaou), Beni Hoppe, Summer Princess, HS138 (Natsumi), Natsumusume (Kareinya), Yayoihime, Pechika, Kaorino (registered trademark), Wada Hatsu Koi, Omotome Ichigo, Chiba S4, Diamond Berry, Albion, Monterey, Sakihime, Oita 6, etc.

[0012] <Total content of strawberry aroma components> The strawberry according to one embodiment 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 1150 ppb or more and 14100 ppb or less. In the strawberry according to one embodiment of the present invention, the total aroma component content is 1150 ppb or more, so that the fruity aroma of the strawberry is enhanced and the flavor is excellent. In addition, in the strawberry according to one embodiment of the present invention, the total aroma component content is 14100 ppb or less, so that the fresh strawberry aroma is good and the flavor is excellent. If the total aroma component content exceeds 14100 ppb, an off-flavor will be felt. The strawberry aroma components can be measured by a measurement method commonly used in the art, for example, by using GC-MS.

[0013] <Ethyl acetate> Ethyl acetate is an aroma component that has a pineapple or banana-like aroma. As the amount of ethyl acetate increases, the fruity aroma increases. In the present invention, the total strawberry aroma component content range is preferably 300 ppb or more. On the other hand, in the high concentration range, it acts as an off-flavor, also known as a paint thinner smell, so it is preferably 10,000 ppb or less to maintain a good aroma.

[0014] <Ethyl butyrate> Ethyl butyrate, like ethyl acetate, is an aroma component that exhibits a pineapple or banana-like aroma. As the amount of ethyl butyrate increases, the fruity aroma increases. In the strawberry according to one embodiment of the present invention, the content of ethyl butyrate 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, while in the high concentration range, it acts as an off-flavor, also known as an ether smell, so that the content is preferably 4,000 ppb or less in order to maintain a good aroma.

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

[0016] <Ethyl isovalerate> Ethyl isovalerate is an aroma component that exhibits a sweet aroma reminiscent of grapes or apples. Increasing the amount of ethyl isovalerate increases the fruity aroma. In strawberries, which is one embodiment of the present invention, the content of ethyl isovalerate is preferably 1 ppb or more within the range of the total content of strawberry aroma components in the present invention, and is preferably 500 ppb or less because a high concentration range gives an artificial aroma.

[0017] <Ethyl hexanoate> Ethyl hexanoate is an aroma component that gives off a gorgeous aroma unique to strawberries. As the amount of ethyl hexanoate increases, the fruity aroma also increases. In strawberries, which is one embodiment of the present invention, the content of ethyl hexanoate is preferably 10 ppb or more within the range of the total content of strawberry aroma components in the present invention, and is preferably 2,200 ppb or less because a high concentration range causes a fermented odor or an artificial odor.

[0018] <The sum of the contents of ethyl 2-methylbutyrate and ethyl isovalerate in strawberries> In addition, in the strawberries according to one embodiment of the present invention, the sum of the contents of ethyl 2-methylbutyrate and ethyl isovalerate is preferably 14 ppb or more from the standpoint of the fruity aroma of strawberries, more preferably 20 ppb or more, and even more preferably 30 ppb or more. Furthermore, since high concentrations give the impression of an artificial aroma, the sum of the contents is preferably 1000 ppb or less, and more preferably 600 ppb or less.

[0019] <Strawberry aroma component content> In addition, in the strawberry according to one aspect 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. Furthermore, from the viewpoint of imparting a fruity aroma, the ratio is preferably 1:40 or less.

[0020] <Use of strawberries according to one aspect of the present invention> The strawberries according to one embodiment of the present invention may be eaten as they are, or may be used as ingredients in processed foods. The strawberries according to one embodiment of the present invention have an increased amount of aroma components, so that the aroma components remain in large amounts even after processing. This can further improve the flavor of the processed food. In order to achieve the desired flavor of the processed food, the amount of the strawberries according to one embodiment of the present invention may be appropriately increased or decreased. The strawberries according to one embodiment of the present invention may be frozen and stored. The frozen strawberries still contain a large amount of aromatic components. Examples of freezing methods include IQF (Individual Quick Frozen) and BQF (Block Quick Freezing).

[0021] <Method of producing strawberries according to the present invention> A method for producing strawberries with increased amounts 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 "storage step"), and the volume ratio of the container to the volume of the strawberries is greater than 1 and less than 10. By the production method according to one embodiment of the present invention, strawberries with excellent flavor and 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 the strawberries used in the strawberry manufacturing method according to one embodiment of the present invention is not particularly limited, but examples include fresh strawberries, frozen strawberries, and the like. Fresh strawberries refer to strawberries that have not been frozen or dried after harvesting. Pretreatment may involve sterilization by a conventionally known method, washing of fresh strawberries, removal of stems, and the like. It is preferable to carry out a similar pretreatment in the case of frozen strawberries.

[0023] <Storage process> The storage step in the manufacturing method according to one embodiment of the present invention is 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. The volume of the container used in the storage step is set to the volume described below, which can increase the amount of aroma components in the strawberries. The present inventors speculate that this is a metabolic action that starts from the respiration of the strawberries. In other words, the present inventors have found that the respiration of the strawberries is restricted by changing the environment in the container, as the CO2 concentration in the container increases and the O2 concentration decreases due to respiration. In addition, the volume of the container has been found to increase the effect of the change in the environment due to respiration on the increase in the amount of aroma components, and they have succeeded in increasing the amount of aroma components even in a short period of time of 72 hours or shorter.

[0024] <Container> The volume ratio of the container used in the storage step in one embodiment of the present invention is greater than 1 and less than 10 relative to the volume of the strawberries. The presence of air in addition to strawberries in the container can favorably increase the amount of aroma components of the strawberries. From the viewpoint of ensuring a necessary and sufficient amount of oxygen for the strawberries to breathe, the volume ratio of the container is preferably 1.05 or more relative to the volume of the strawberries, more preferably 1.1 or more, and even more preferably 2.0 or more. From the viewpoint that respiration can cause changes in the environment, it is preferably 10 or less. The volume of the container means the volume of the internal space including the volume of the strawberries.

[0025] The structure of the container may be any structure that can seal the container. The container may be equipped with a refrigeration system or the like to keep the temperature inside the container constant. The container may also be equipped with a device for controlling the gas composition of CO2 or the like to manage the CO2 concentration inside the container.

[0026] <Storage temperature> The temperature at which the strawberries are stored during the storage process is 0°C or higher, preferably 2°C or higher, from the viewpoint of promoting respiration, and is 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> The time for storing the strawberries in the storage step is 8 hours or more, more preferably 10 hours or more, and even more preferably 12 hours or more, from the viewpoint of increasing the amount of aroma components, and is 72 hours or less, more preferably 48 hours or less, and even more preferably 24 hours or less, from the viewpoint of maintaining the freshness of the strawberries and preventing the growth of bacteria.

[0028] <Carbon dioxide concentration> The storage process may be controlled based on the volume of the container, the storage temperature, and the storage time described above, as well as the CO2 concentration within the container to limit respiration of the strawberries. For example, from the viewpoint of increasing the amount of aroma components, it is preferable to store the product so that the concentration is 1.5% or more, and more preferably 2.5% or more. Also, from the viewpoint of preventing deterioration of flavor due to an excessive increase in the concentration of ethyl acetate, etc., it is preferable to store the product so that the concentration is 15% or less, and more preferably 10% or less.

[0029] The present invention will be specifically described below based on examples and comparative examples, but the present invention is not limited thereto. EXAMPLES

[0030] An example of the present invention will be described below. In this example, strawberries stored under the following conditions were subjected to aroma component and sensory evaluation.

[0031] [Examples 1 to 19, Comparative Examples 1 to 16] <Strawberry production> 250g (volume equivalent: 0.26L) or 1200g (volume equivalent: 12.6L) of the harvested strawberry samples were placed in pouch bags (Meiwapax Co., Ltd., Barrier NY15 / Dry / LLD#60) or pail cans (volume 21.875L) with the volumes shown in Tables 1 to 4, sealed, and stored at the temperature and time shown in each table. Five strawberry varieties were used: Yume Tsuzuki, Yume Tsuzuki No. 2, Beni Hoppe, Monterey, and Takara Kou Wase.

[0032] <Measurement of aroma components> Aroma components were measured for strawberries stored under the conditions in Tables 1 to 4 below. Some strawberries were frozen and stored by IQF or BQF until the aroma components were measured, and then thawed before the measurement. The examples shown as "fresh" in Tables 1 to 4 are examples in which aroma components were measured after storage without freezing.

[0033] The aroma components were measured by the following method. First, as an aroma component extraction and concentration column, 20 mL of PorapakQ (ethylvinylbenzene-divinylbenzene copolymer, 50-80 meah, manufactured by Waters) was packed in a filter-equipped glass column (φ2 cm × 20 cm) and washed with diethyl ether, methanol, and pure water in that order. Next, the sample was homogenized, 50 g was weighed out, 50 mL of pure water was added, and the mixture was centrifuged to obtain a supernatant. 50 mL of pure water was added again to the residue, and the mixture was centrifuged to obtain a supernatant. After adding an internal standard substance (100 ppm cyclohexanol) to the liquid obtained by combining these supernatants, the mixture was passed through the above-mentioned column (20 ml) and washed with pure water, and then the aroma components were eluted from the column with ether. The eluate was dehydrated, concentrated, and injected into a gas chromatograph mass spectrometer (manufactured by Shimadzu Corporation, GCMS QP 2020NX) for analysis. The analysis conditions are shown below. (GC conditions) Column: DB-Wax UI capillary column (J&W), 60 m x 0.25 mm id x 0.25 μm film thickness Column temperature: Initial temperature 40°C, held for 10 min, heated to 220°C at 3.0°C / min and held for 15 min, heated to 245°C at 10.0°C / min and held for 20 min Vaporization 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: 3ml / 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] LabSolutions-GCMSsolution version 2.72 (Shimadzu Corporation) was used for the analysis and analysis software. In this case, the identification of the volatile component compounds was performed by comparing the mass spectrum of the component at a specific retention time obtained by gas chromatography mass spectrometry with the mass spectrum obtained in the same manner using a standard and the mass spectrum of the published library WILEY7, and by comparing the Kovats Index of the peak with the Kovats Index of the standard.

[0035] In addition, when identifying and quantifying the volatile components, the total ion area was not used, but the target ions and reference ions and their relative ratios were used for identification, and the total ion area was calculated using the target ion area as the ratio of the target ions to the total ions of the substance in the published library WILEY7, and quantitative calculations were performed. Similarly, calculations were performed for the internal standard substance cyclohexanol, and the concentration of the substance was expressed as a relative concentration (ppb) to the internal standard substance cyclohexanol.

[0036] <Sensory evaluation of aroma> At the same time, a sensory evaluation was conducted on the strawberry aroma obtained in the examples and comparative examples. A trained panel of five people evaluated the strawberry aroma. The degree to which the strawberry aroma (flavor) was perceived as good was expressed on a scale of 1 to 4 according to the following criteria, with 4 being the highest and 1 being the lowest.

[0037] [Fragrance evaluation criteria] 4: The fruity and sweet scents characteristic of strawberries are well balanced. 3: You can feel the fruity and sweet scent unique to strawberries. 2: A slight hint of the fruity and sweet scent characteristic of strawberries. 1: The fruity and sweet scent characteristic of strawberries is barely detectable.

[0038] [Table 1]

[0039] [Table 2]

[0040] [Table 3]

[0041] [Table 4]

[0042] <Result> As shown in Tables 1 to 4, it was shown that strawberries with increased aroma components can be produced by 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, and setting the volume ratio of the container to the volume of the strawberries to be greater than 1 and less than 10. Specifically, it was shown that strawberries with increased aroma components can be provided that contain ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate, and have a total aroma component content of 1150 ppb or higher and 14100 ppb or lower. It was also shown that such strawberries have excellent flavor.

[0043] Furthermore, among these five aroma components, strawberries with a total content (content of the two components) of ethyl 2-methylbutyrate and ethyl isovalerate of 20 ppb or more and 1,000 ppb or less achieved the highest score of 4 in the sensory evaluation of aroma, and were classified as the strawberries with 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, the 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 excellent flavor. [Industrial Applicability]

[0045] The present invention can be used for processed foods made from fresh strawberries and for eating raw.

Claims

1. The strawberry contains 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, and has an increased amount of aroma components.

2. 2. The strawberry having increased amounts of 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. 3. The strawberry with increased amounts of 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 method includes a step of storing strawberries in a sealed container at a temperature of 0° C. or more and 20° C. or less 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 10 relative to the volume of the strawberries.

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