Strawberry having increased aroma component amount and production method therefor

Abstract

A strawberry according to one embodiment of the present invention includes ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate as aroma components, wherein the total aroma component content is 1,150-14,100 ppb inclusive.

Description

Strawberries with increased aromatic compounds and method for producing the same

[0001] This invention relates to strawberries with increased aromatic components and a method for producing the same.

[0002] Patent Document 1 describes frozen strawberries having a predetermined breaking load and breaking strain. Non-Patent Document 1 describes a method for freezing strawberries using CO2. ２ It has been reported that storing strawberries in a controlled atmosphere and then in 0°C air can maintain their firmness and suppress the development of off-flavors. Furthermore, Non-Patent Literature 2 describes the process of storing wild strawberries in a certain proportion of CO2. ２ and O ２ It has been reported that storing strawberries in this atmosphere suppresses their respiration.

[0003] Japanese Patent No. 6688419

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

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

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

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

[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, and the total content of aroma components is 1150 ppb or more and 14100 ppb or less. The total content of aroma components 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 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 No. 1, Chiba S4, Diamond Berry, Albion, Monterey, Sakihime, Oita No. 6, etc.

[0012] <Total Content of Aroma Components in Strawberries> 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, 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 one aspect of the present invention, a total aroma component content of 1150 ppb or more enhances the fruity aroma of the strawberries, resulting in an excellent flavor. In another aspect of the present invention, a total aroma component content of 14100 ppb or less results in a good fresh strawberry aroma and an excellent flavor. Off-flavors become noticeable when the total aroma component content exceeds 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 a pineapple or banana-like scent. As the amount of ethyl acetate increases, the fruity aroma intensifies. In the total amount of aromatic compounds in the strawberry in this invention, it is preferable that the amount be 300 ppb or more. On the other hand, in the high concentration range, it behaves as an off-flavor, sometimes referred to as a thinner-like odor, so in order to maintain a good aroma, it is preferable that the amount be 10,000 ppb or less.

[0014] <Ethyl Butyrate> Ethyl butyrate is an aroma component that exhibits a pineapple or banana-like scent, similar to ethyl acetate. An increase in ethyl butyrate enhances the fruity aroma. In the strawberry according to one aspect 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 aspect of the present invention. On the other hand, in the high concentration range, it behaves as an off-flavor, sometimes referred to as an ether odor, so it 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 fragrant fruity aroma. The fruity aroma increases as the amount of ethyl 2-methylbutyrate increases. In 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 aroma components of strawberries in the present invention, and is preferably 900 ppb or less because it can be perceived as an artificial aroma at high concentrations.

[0016] <Ethyl Isovalerate> Ethyl isovalerate is an aromatic compound that exhibits a sweet scent reminiscent of grapes and apples. An increase in ethyl isovalerate enhances the fruity aroma. In the case of strawberries, which is one embodiment of the present invention, the ethyl isovalerate content is preferably 1 ppb or more within the range of the total aromatic compound content of strawberries in the present invention, and is preferably 500 ppb or less, as high concentrations may be perceived as an artificial scent.

[0017] <Ethyl Hexanoate> Ethyl hexanoate is an aromatic component that exhibits the characteristic, fragrant aroma of strawberries. As the amount of ethyl hexanoate increases, the fruity aroma increases. In one embodiment of the present invention, the content of ethyl hexanoate is preferably 10 ppb or more within the range of the total aromatic component content of the strawberries in the present invention, and preferably 2,200 ppb or less, as high concentrations can be perceived as fermented or artificial.

[0018] <Sum of ethyl 2-methylbutyrate and ethyl isovalerate content in strawberries> In addition, in the strawberries according to one embodiment of the present invention, the sum of the content 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, and since it can be perceived as an artificial scent at high concentrations, it is preferably 1000 ppb or less, and even more preferably 600 ppb or less. In other words, the sum of the content of ethyl 2-methylbutyrate and ethyl isovalerate is preferably 14 ppb to 1000 ppb, more preferably 20 ppb to 600 ppb, and even more preferably 30 ppb to 600 ppb.

[0019] <Ratio of aroma components in strawberries> In addition, in a strawberry according to one aspect of the present invention, 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 preferably 1:4 or more and 1:81 or less. Furthermore, from the viewpoint of imparting a fruity aroma, 1:40 or less is preferred.

[0020] <Uses of Strawberries According to One Embodiment of the Invention> Strawberries according to one embodiment of the invention may be eaten as is or used as an ingredient in processed foods. Because the strawberries according to one embodiment of the invention have an increased amount of aromatic components, a large amount of aromatic components remain even after processing. This can further improve the flavor of processed foods. In order to achieve the desired flavor in processed foods, the amount of strawberries according to one embodiment of the invention can be appropriately increased or decreased. Furthermore, strawberries according to one embodiment of the invention may be frozen for storage. Strawberries that have been frozen also contain a large amount of aromatic components. Examples of freezing methods include IQF (Individual Quick Frozen) and BQF (Block Quick Frozen).

[0021] <Strawberry Production Method According to the Present Invention> A method for producing strawberries with increased aroma components according to one aspect of the present invention (hereinafter referred to as "the production method according to one aspect 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 more and 72 hours or less (hereinafter the storage step is referred to as the "storage step"), wherein the volume ratio of the container is greater than 1 and 10 or less to the volume of the strawberries. By the production method according to one aspect of the present invention, strawberries with excellent flavor containing a well-balanced amount of aromas derived from ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate are produced.

[0022] <Strawberries> 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 mean 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 process in the manufacturing method according to one aspect of the present invention is to place the strawberries in a sealed container and store them at a temperature of 0°C or higher and 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 aromatic components of the strawberries can be increased. The inventors of this invention speculate that this is due to metabolic activity initiated by the respiration of the strawberries. In other words, the inventors of this invention speculate that the CO2 in the container is released by respiration. ２ The concentration increased, O ２ We found that reducing the concentration and altering the environment inside the container restricts strawberry respiration, leading to an increase in aromatic compounds. Furthermore, we determined the optimal container volume to maximize the effect of environmental changes due to respiration on the increase in aromatic compounds, and succeeded in increasing aromatic compounds in a short period of less than 72 hours.

[0024] <Container> In the storage process according to one embodiment of the present invention, the volume ratio of the container used 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 structure only needs to be designed to be airtight. Refrigeration equipment may be provided to maintain a constant temperature inside the container. Also, the CO2 inside the container... ２ CO2 ２ The system may also be equipped with devices for controlling the gas composition, such as those mentioned above.

[0026] <Storage Temperature> When storing strawberries in the storage process, the temperature should be 0°C or higher, preferably 2°C or higher, from the perspective of promoting respiration. Also, from the perspectives of maintaining the freshness of strawberries and preventing the growth of miscellaneous bacteria, it should be 20°C or lower, preferably 15°C or lower. That is, the temperature for storing strawberries in the storage process is preferably 0°C to 20°C, and more preferably 2°C to 15°C.

[0027] <Storage Time> The time for storing strawberries in the storage process is 8 hours or more, more preferably 10 hours or more, and even more preferably 12 hours or more, from the perspective of increasing the amount of aroma components. Also, from the perspectives of maintaining the freshness of strawberries and preventing the growth of miscellaneous bacteria, it is 72 hours or less, more preferably 48 hours or less, and even more preferably 24 hours or less. That is, the storage time for strawberries in the storage process is preferably 8 hours to 72 hours, more preferably 10 hours to 48 hours, and even more preferably 12 hours to 24 hours.

[0028] <Carbon Dioxide Concentration> In addition to the volume of the above-mentioned container, storage temperature, and storage time, the storage process may be managed based on the CO ２ concentration in order to limit the respiration of strawberries. For example, from the perspective of increasing the amount of aroma components, it is preferably stored so that the concentration becomes 1.5% or higher, and more preferably 2.5% or higher. Also, from the perspective of preventing flavor deterioration due to excessive concentration increase of ethyl acetate, etc., it is preferably stored so that the concentration becomes 15% or lower, and more preferably 10% or lower. That is, the CO ２ concentration in the container is preferably 1.5% to 15%, and more preferably 2.5% to 10%.

[0029] Hereinafter, the present invention will be specifically described based on examples and comparative examples. Note that the present invention is not limited thereto.

[0030] (Summary) In other words, one aspect of the present invention is: (1) Strawberries with increased aroma components, comprising ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate as aroma components, wherein the total content of the aroma components is 1150 ppb or more and 14100 ppb or less; (2) Strawberries with increased aroma components as 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 with increased aroma components as 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.

[0031] 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.

[0032] [Examples 1-19, Comparative Examples 1-16] <Strawberry Preparation> 250 g (volume equivalent: 0.26 L) or 1200 g (volume equivalent: 12.6 L) of harvested strawberry samples were placed in pouches (Meiwa Pax Co., Ltd., Barrier NY15 / Dry / LLD #60) or pails (volume 21.875 L) of the volumes shown in Tables 1-4, 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.

[0033] <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 of aroma components, and then thawed before measurement. Examples marked "raw" in Tables 1-4 are examples where aroma components were measured after storage without freezing.

[0034] The aroma components were measured using the following method. First, as an aroma component extraction and concentration column, 20 mL of Porapak Q (ethyl vinylbenzene-divinylbenzene copolymer, 50-80 mesh, Waters) was packed into a filtered glass column (φ2 cm × 20 cm) and washed in the following 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 as follows: (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 min, increased temperature to 220°C at 3.0°C / min and held for 15 min, increased temperature to 245°C at 10.0°C / min and held for 20 min Vaporization chamber temperature: 230°C Injection mode: Split; Split ratio 1:5 Carrier gas: He Column inlet pressure: 185kPa Linear velocity: 34.2cm / s Purge flow rate: 3ml / min Injection volume: 1.0μl MS conditions Ion source temperature: 200°C Interface temperature: 230°C Detector gain voltage: 1.05kV Scan MS: m / z: 29-350

[0035] 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 sample and the mass spectrum of the published library WILEY7, and then comparing the Kovats Index of the peak in question with the Kovats Index of the standard sample.

[0036] Also, when identifying and quantifying volatile components, instead of using the total ion area, identification was performed using target ions, reference ions, and their relative ratios to each other, and the total ion area was calculated by the ratio of the target ion area to the total ion of the substance in the published library WILEY7, and quantitative calculations were performed. Similarly, the internal standard substance cyclohexanol was also calculated, and the concentration of the substance was expressed as the relative concentration (ppb) to the internal standard substance cyclohexanol.

[0037] <Sensory evaluation of aroma> At the same time, sensory evaluations of the aroma of strawberries obtained in the examples and comparative examples were performed. The evaluation was carried out by 5 trained panelists who evaluated the aroma of strawberries. The degree of feeling that the aroma (flavor) of strawberries is good was expressed as 1 to 4 points according to the following evaluation criteria, with the highest point being 4 and the lowest point being 1.

[0038] [Aroma evaluation criteria] 4: A full fruity aroma and a sweet aroma characteristic of strawberries are felt in good balance. 3: A full fruity aroma and a sweet aroma characteristic of strawberries are felt. 2: A slight fruity aroma and a sweet aroma characteristic of strawberries are felt. 1: Almost no fruity aroma and sweet aroma characteristic of strawberries are felt.

[0039]

[0040]

[0041]

[0042]

[0043] <Results> As shown in Tables 1 to 4, by including the 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 more and 72 hours or less, and setting the volume ratio of the container to be greater than 1 and 10 or less with respect to the volume of strawberries, it was shown that strawberries with an increased amount of aroma components can be produced. Specifically, it was shown that strawberries containing ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate, and having a total content of aroma components of 1150 ppb or more and 14100 ppb or less, can be provided as strawberries with an increased amount of aroma components. Also, it was shown that such strawberries are excellent in flavor.

[0044] Furthermore, among these five types of 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.

[0045] 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.

[0046] This invention can be used for fresh consumption and for processed foods made from fresh strawberries.

Claims

1. Strawberries with increased aroma components, comprising ethyl acetate, ethyl butyrate, ethyl 2-methylbutyrate, ethyl isovalerate, and ethyl hexanoate as aroma components, 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. A method for producing strawberries with increased aromatic components, comprising the steps 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.

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