JP2023059126A - Composition, coated food, method for producing coated food, coat forming method and food shipment method - Google Patents

Abstract

To provide a composition that is applied in liquid form to the surface of food, so that the liquid dries quickly, and the appearance of the coated surface also becomes good.SOLUTION: A composition contains a sugar-based surfactant and an aqueous solvent. The composition has a surface tension of 34 mN/m or less at 25°C.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a composition, a film-coated food product, a film-coated food production method, a film-forming method, and a food shipping method.

BACKGROUND ART In recent years, attention has been focused on packaging materials, such as MA (Modified Atmosphere) packaging, which can maintain the freshness of food during distribution or storage. From the viewpoint of reducing the burden on the environment, packaging materials to be used tend to be made of a single material so that they can be easily recycled or discarded after use.
Further, a technique has been proposed to directly apply a quality preserving agent to food such as fruits and vegetables to keep the food fresh without using a packaging material (see Patent Documents 1 and 2).
Furthermore, for the purpose of preventing pericarp damage to fruits and vegetables, an agent for preventing pericarp damage to fruits and vegetables, which contains a surfactant having an HLB of 5 or less as an active ingredient, has been proposed (see Patent Document 3).

JP 2018-134115 A Japanese translation of PCT publication No. 2005-530502 JP-A-8-56564

However, the methods disclosed in Patent Documents 1 and 2 have a short freshness retention period, the materials used are compositions that are not friendly to the human body, and are not necessarily sufficient for expressing the freshness retention performance.
In addition, when the liquid agent disclosed in Patent Document 3 is applied to foods such as fruits and vegetables, it takes a long time to dry, resulting in poor productivity in some cases. In addition, traces of application may be seen, and the surface of the applied food may be whitened, resulting in poor appearance of the coating film.
Accordingly, an object of the present invention is to propose a composition capable of forming a film that dries quickly and has a good appearance after application when the coating liquid is applied to the surface of food.

The present inventors considered that transpiration from food during distribution or storage is one of the causes of deterioration in freshness, and have conducted various studies on coatings with high water vapor barrier properties. They also found that by controlling the surface tension of the composition that constitutes the coating liquid, when the coating liquid is applied to the surface of food, the drying rate is fast and the appearance after application is good. The present invention has been completed based on such findings.

That is, the present invention has the following aspects.
[1] A composition containing a sugar-based surfactant and an aqueous solvent and having a surface tension of 34 mN/m or less at 25°C.
[2] The composition according to [1] above, wherein the main component of the sugar-based surfactant is a sugar fatty acid ester.
[3] The composition according to [2] above, wherein the weight ratio of the saturated fatty acid to the unsaturated fatty acid in the fatty acid constituting the sugar fatty acid ester is from 50/50 to 99/1.
[4] The composition according to [2] or [3] above, which contains 50 to 98% by mass of a sugar fatty acid ester having 3 or less fatty acid ester groups out of 100% by mass of the sugar fatty acid ester.
[5] The composition according to any one of [2] to [4] above, containing 2 to 50% by mass of a sugar fatty acid ester having 5 or more fatty acid ester groups out of 100% by mass of the sugar fatty acid ester. thing.
[6] The composition according to any one of [1] to [5] above, wherein the concentration of non-volatile components in the composition is 0.1% by mass or more and 20% by mass or less.
[7] The composition according to any one of [1] to [6] above, wherein the content of the sugar-based surfactant is 60% by mass or more among the non-volatile components in the composition.
[8] The composition according to any one of [1] to [7] above, wherein the aqueous solvent is water or a mixture of water and alcohol.
[9] The composition according to [8] above, wherein the content of the alcohol is 1% by mass or more and 30% by mass or less.
[10] The composition according to any one of [1] to [9] above, which is used for coating fruits and vegetables.
[11] A film-coated food having a film comprising the composition according to any one of [1] to [9] above.
[12] The film-coated food according to [10] above, wherein the food is a fruit or vegetable.
[13] A method for producing a film-coated food, comprising the step of applying the composition according to any one of [1] to [9] above to the food.
[14] The method for producing a film-coated food according to [13] above, wherein the coating method is an immersion method or a spray method.
[15] The method for producing a film-coated food according to [13] or [14] above, wherein the composition or the sugar-based surfactant is applied to a portion of the food.
[16] The method for producing a film-coated food according to [13] or [14] above, wherein after applying the composition to the food, part of the applied composition is removed.
[17] A method for forming a film, comprising the step of applying the composition according to any one of [1] to [9] above to food.
[18] The method of forming a film according to [17] above, wherein the coating method is an immersion method or a spray method.
[19] The method of forming a film according to [17] or [18] above, wherein the composition is applied to a portion of food.
[20] The method of forming a film according to [17] or [18] above, wherein after the composition has been applied to the food, part of the applied composition is removed.
[21] A food shipping method comprising (A) a step of conveying food, (B) a step of forming a film on the food, and (C) a step of inspecting the food with the film using an evaluation device, A method for shipping food, wherein in the step (B), a film is formed by the method according to any one of [17] to [20] above.
[22] The method for shipping food according to [21] above, wherein the inspection step (C) includes at least one inspection selected from the group consisting of an appearance inspection, a sugar content inspection, and a size inspection.

By using the composition of the present invention, when applied to foods such as fruits and vegetables, the drying rate is fast and the appearance after application is good.

1 is an image diagram of a shipping method for fruits and vegetables according to the present invention; FIG.

<Composition>
The composition of the present invention contains a sugar-based surfactant and an aqueous solvent. A film obtained from the composition has excellent water vapor barrier properties, and is suitable for coating food. In addition, since the film also has oxygen barrier properties, it is particularly suitable for coating fruits and vegetables. In addition, the film obtained from the composition is preferably freed from the aqueous solvent as described later.

(surface tension)
The composition of the present invention has a surface tension of 34 mN/m or less at 25°C. By setting the surface tension at 25° C. to 34 mN/m or less, the liquid of the composition after it is applied to the food can be easily drained off, so that the drying speed can be increased. In addition, good liquid drainage prevents the coating liquid from excessively remaining on foods such as fruits and vegetables, so that traces of coating and whitening of the coating film are less likely to occur. From the above viewpoints, the surface tension at 25° C. is more preferably 32 mN/m or less, and even more preferably 30 mN/m or less.
Although the lower limit is not particularly limited, it is usually 10 mN/m or more, preferably 15 mN/m or more, and more preferably 20 mN/m or more.
The surface tension can be measured by the method described in Examples.

(Defoaming time)
The defoaming time of the composition of the present invention at 25° C. is preferably 60 minutes or less, more preferably 40 minutes or less, still more preferably 20 minutes or less, and 10 minutes or less. Even more preferable. When the defoaming time is within the above range, it is possible to prevent traces of foam from remaining even after drying when foam is generated due to liquid transfer or the like in the coating process. Since the defoaming time is preferably as short as possible, the defoaming time should be 0 minute or more.
The defoaming time can be measured by the method described in Examples.

[Sugar surfactant]
A sugar-based surfactant is a nonionic surfactant having a sugar as a hydrophilic group.
Examples of the sugar-based surfactants of the present invention include sugar fatty acid esters formed by ester bonding of sugar and fatty acid, and alkyl glycosides formed by glycosidic bonding of sugar and higher alcohol, among which sugar fatty acid esters are preferred.

(sugar fatty acid ester)
In the composition of the present invention, the main component of the sugar-based surfactant is preferably a sugar fatty acid ester. Here, the main component means that the sugar fatty acid ester is the most abundant component in the sugar-based surfactant, and is, for example, 50% by mass or more, preferably 60% by mass or more, and 70% by mass or more. is more preferable, 80% by mass or more is more preferable, and 90% by mass or more is even more preferable. The sugar-based surfactant may be used alone as a sugar fatty acid ester, and therefore it is sufficient if it is 100% by mass or less.
By using a sugar fatty acid ester as the main component of the sugar-based surfactant, it is possible to suppress the stickiness of the obtained film and improve the water vapor barrier properties and oxygen barrier properties. For the same reason, the sugar-based surfactant preferably has crystallinity. Since the sugar fatty acid ester easily forms a crystal structure when formed into a film, the obtained film can have high water vapor barrier properties and oxygen barrier properties.

Sugars in sugar fatty acid esters may be any of monosaccharides, disaccharides, trisaccharides, tetrasaccharides, polysaccharides, sugar alcohols and other oligosaccharides.
Monosaccharides include pentoses such as ribulose, xylulose, ribose, arabinose, xylose, lyxose and deoxyribose; Examples include hexoses such as fucrose and rhamnose.
Disaccharides include sucrose, lactose, maltose, trehalose, turanose, cellobiose and the like.
Trisaccharides include raffinose, melezitose, maltotriose and the like.
Tetrasaccharides include acarbose, stachyose and the like.
Polysaccharides include glycogen, starch, cellulose, dextrin, glucan, fructan, chitin and the like.
Sugar alcohols include sorbitol, erythritol, xylitol, maltitol, lactitol, mannitol, glycerin, etc. Condensates of these sugar alcohols may also be used.
Other oligosaccharides include fructo-oligosaccharides, galacto-oligosaccharides, mannan-oligosaccharides, lactosucrose and the like.
Among the above, from the viewpoint of availability, sugar fatty acid esters containing disaccharides are preferable, and sugar fatty acid esters containing sucrose, that is, sucrose fatty acid esters are more preferable.
In addition, it is not necessary to use only one type of sugar fatty acid ester, and two or more types may be used in combination. When two or more types are combined, it is preferable that 60% by mass or more of 100% by mass of sugar fatty acid ester is sucrose fatty acid ester. This ratio is more preferably 70% by mass or more, still more preferably 80% by mass or more, and even more preferably 90% by mass or more, from the viewpoint of suppressing the stickiness of the obtained coating and increasing the water vapor barrier property and oxygen barrier property. preferable. The sugar fatty acid ester may be a sucrose fatty acid ester alone, and therefore the above ratio should be 100% by mass or less.

The range of the number of fatty acid ester groups in the sugar fatty acid ester varies depending on the number of ester-bondable hydroxyl groups in the molecular structure of the sugar, which is a hydrophilic group. 2 to 4.

The composition of the present invention contains a sugar fatty acid ester (monoester, diester or triester; hereinafter sometimes referred to as "low fatty acid ester") having 3 or less fatty acid ester groups in 100% by mass of the sugar fatty acid ester. It preferably contains 50 to 98% by mass. This ratio is more preferably 60% by mass or more, and even more preferably 70% by mass or more, from the viewpoint of improving the solubility in an aqueous solvent. Further, it is more preferably 95% by mass or less, still more preferably 90% by mass or less, still more preferably 85% by mass or less, and even more preferably 80% by mass or less.

In addition, the composition of the present invention is a sugar fatty acid ester having 5 or more fatty acid ester groups (pentaester, hexaester, heptaester, octaester, etc.; hereinafter referred to as "high fatty acid ester") in 100% by mass of sugar fatty acid ester. ) is preferably contained in an amount of 2 to 50% by mass. From the viewpoint of increasing the stability of the composition, this ratio is preferably 5% by mass or more, more preferably 10% by mass or more. Moreover, it is preferably 40% by mass or less, more preferably 30% by mass or less, and even more preferably 20% by mass or less.

The composition of the present invention may contain a sugar fatty acid ester (tetraester) having four fatty acid ester groups in addition to the low fatty acid ester and the high fatty acid ester.
In 100% by mass of sugar fatty acid ester, the content of tetraester may be 0% by mass or more, preferably 5% by mass or more, and more preferably 10% by mass or more. Moreover, 48 mass % or less is preferable, 40 mass % or less is more preferable, and 35 mass % or less is further more preferable.

In addition, the content ratio for each number of fatty acid ester groups, after isolating the sugar fatty acid ester from the composition, Residue Monograph prepared by the meeting of the Joint FAO/WHO Expert Committee on Food Additives (JECFA), 84th meeting 2017 “Sucrose Esters of Fatty Acids” and Prepared at the 71st JECFA (2009) and published in FAO JECFA Monographs 7 (2009) “Sucrose Oligoesters Type I” and “Sucrose Oligoesters Type II”. .

《Measurement of monoester, triester and tetraester or higher》
After dissolving the sample in a certain amount of tetrahydrofuran (stabilizer-containing GPC or industrial grade), insoluble matter was removed with a 0.5 μm membrane filter. do. For the composition ratio, the peak areas of monoester to triester and the peak areas of tetraester and higher are individually calculated, and the ratio of all peaks detected up to 43 minutes to the total peak area is calculated.
The peak area corresponds to the area from the starting point (rising position) to the ending point (falling position) of each peak.
When two or more peaks are adjacent to each other and the start point and end point are unknown, the area is calculated using the point where the data between the peaks becomes minimum as the start point and end point.

<Measurement conditions: monoester to triester and tetraester or higher>
Apparatus: HLC-8320GPC Detector: Differential refractometer (manufactured by Tosoh Corporation)
Column: TSK-gel G1000HXL, G2000HXL, G3000HXL, G4000HXL (manufactured by Tosoh Corporation)
Column temperature: 40°C
Detector temperature: 40°C
Eluent: Tetrahydrofuran (GPC with stabilizer or industrial grade)
Flow rate: 0.8ml/min
Injection volume: 80 μl
Measurement time: 50 minutes (calculate the area ratio based on all peaks detected by 43 minutes)

<<Measurement of tetraester to octaester>>
After dissolving the sample in a certain amount of methanol (reagent special grade) / tetrahydrofuran (HPLC grade without stabilizer) = 20/80 (vol/vol), measure the solution after removing insoluble matter with a 0.45 μm membrane filter. A sample is subjected to high performance liquid chromatography under the following conditions. The composition ratio of tetraester to octaester is obtained by calculating the peak area of each of tetraester to octaester individually, calculating the ratio to the total peak area of tetraester to octaester, and calculating the above <<monoester to triester and tetraester. The area ratio of the tetraester or higher obtained in the measurement described above is proportionally calculated by the area ratio of the tetraester to the octaester.
The peak area corresponds to the area from the starting point (rising position) to the ending point (falling position) of each peak.
When two or more peaks are adjacent to each other and the start point and end point are unknown, the area is calculated using the point where the data between the peaks becomes minimum as the start point and end point.

<Measurement conditions: tetraester to octaester>
Device degasser: DGU-20A (manufactured by Shimadzu Corporation)
Pump: LC-20AD (manufactured by Shimadzu Corporation)
Oven: CTO-20A (manufactured by Shimadzu Corporation)
Detector: RID-20A differential refractometer (manufactured by Shimadzu Corporation)
Column: 150mm x 4.6mm i. d. ; ODS-2 (manufactured by GL Science)
Column temperature: 40°C
Detector temperature: 40°C
Eluent: methanol (reagent special grade) / tetrahydrofuran (stabilizer-free HPLC grade) = 70/30 to 50/50 (vol/vol)
Flow rate: 0.8ml/min
Injection volume: 20 μl
Measurement time: 16 minutes

The constituent fatty acid of the sugar fatty acid ester is preferably an edible fat.
The number of carbon atoms in the constituent fatty acid of the sugar fatty acid ester is not particularly limited, but is preferably 12 or more and 22 or less, more preferably 12 or more and 18 or less, and even more preferably 14 or more and 18 or less. When the number of carbon atoms is within the above range, stickiness of the obtained coating can be suppressed.

The constituent fatty acid of the sugar fatty acid ester may be a saturated or unsaturated fatty acid, but from the viewpoint of improving the liquid drainage of the composition, the drying speed and the appearance of the coating film, both saturated fatty acid and unsaturated fatty acid are used. It is more preferable to include

The sugar fatty acid ester (a) having a saturated fatty acid tends to become solid at room temperature (20 to 25° C.), and can suppress the stickiness of the obtained film. In addition, since the sugar fatty acid ester (a) tends to have a regular structure in the coating, the obtained coating can have high water vapor barrier properties and oxygen barrier properties.
More specific examples of saturated fatty acids include lauric acid, myristic acid, pentadecyl acid, palmitic acid, margaric acid, stearic acid, and behenic acid. Among them, lauric acid, myristic acid, palmitic acid, and stearic acid are preferred. More preferred are myristic acid, palmitic acid and stearic acid. These saturated fatty acids may be used singly or in combination of two or more.

A sugar fatty acid ester (b) having an unsaturated fatty acid tends to be liquid at room temperature (20 to 25°C). Containing the sugar fatty acid ester (b) reduces the surface tension of the composition, so that the drying speed after application is increased, and traces of the coating solution are less likely to remain on the food.
More specific examples of unsaturated fatty acids include palmitoleic acid, oleic acid, and erucic acid, with oleic acid and erucic acid being preferred. These unsaturated fatty acids may be used singly or in combination of two or more.
The constituent fatty acid composition of the sugar fatty acid ester can be measured by gas chromatography after isolating the sugar fatty acid ester from the composition and derivatizing it.

The blending ratio of sugar fatty acid ester (a) and sugar fatty acid ester (b) is preferably adjusted so that the mass ratio of saturated fatty acid to unsaturated fatty acid is 50/50 to 99/1. The mass ratio is more preferably 50/50 to 90/10, even more preferably 50/50 to 80/20, even more preferably 55/45 to 70/30.

[Aqueous solvent]
The aqueous solvent contained in the composition of the present invention contains at least water.
Also, from the viewpoint of liquid stability, drying speed after coating, and coating film appearance, a mixture of water and an organic solvent having an affinity for water is preferable. is more preferred.
The content of water in the composition is preferably 70% by mass or more and 99% by mass or less, more preferably 80% by mass or more and 98% by mass or less, and more preferably 90% by mass or more and 95% by mass or less.
On the other hand, the content of the organic solvent in the composition is preferably 1% by mass or more and 30% by mass or less, more preferably 2% by mass or more and 20% by mass or less, and more preferably 3% by mass or more and 10% by mass or less.

[Other ingredients]
The composition of the present invention may contain surfactants other than the above sugar-based surfactants, pH adjusters, and the like.
Examples of surfactants other than the above sugar-based surfactants include organic acid monoglycerides, propylene glycol fatty acid esters, polysorbates, and lecithin. The content of these surfactants is preferably 0% by mass or more and 40% by mass or less, more preferably 1% by mass or more and 30% by mass or less, and 5% by mass or more and 20% by mass of the nonvolatile components in the composition. % or less is more preferable.
Examples of pH adjusters that can be used include acetic acid, lactic acid, citric acid, and ammonia. From the viewpoint of safety, the content of the pH adjuster is preferably such that the pH of the composition is 4 or more and 10 or less, preferably 4 or more and 8 or less.

[Physical properties of composition]
(Non-volatile component concentration)
The non-volatile component concentration in the composition of the present invention is not particularly limited, but is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 15% by mass or less, and 1% by mass or more and 10% by mass. More preferred are: When the non-volatile component concentration is within the above range, it becomes easier to form a film having a suitable film thickness, so transpiration from food can be effectively suppressed. Moreover, since it is possible to prevent excessive application of the coating liquid, traces of the coating liquid are less likely to remain.
In addition, the "non-volatile component concentration" in the present invention is the concentration of non-volatile components excluding the solvent contained in the composition.

(Content of sugar surfactant)
The content of the sugar-based surfactant is 60% by mass or more, with an upper limit of 100% by mass, of the non-volatile components in the composition, from the viewpoint of improving the water vapor barrier properties and oxygen barrier properties of the resulting coating film. , more preferably 70% by mass or more, even more preferably 80% by mass or more, and even more preferably 90% by mass or more.
Since the film in the present invention is obtained by volatilizing the solvent from the composition, the preferred content of the sugar-based surfactant in the film is the same as above.

(pH of composition)
The pH of the composition is preferably 4 or more and 10 or less, more preferably 4 or more and 8 or less, from the viewpoint of being safely applicable to food.

(HLB of sugar surfactant)
Although the HLB of the sugar-based surfactant of the present invention is not particularly limited, it is preferably 5 or more, more preferably 7 or more, and even more preferably 9 or more from the viewpoint of forming a film using an aqueous solvent. The upper limit of HLB is usually 20, preferably 18 or less.

<Food with film>
The composition of the present invention is extremely effective for coated food applications in which food is directly coated to form a coating. Since the film has excellent water vapor barrier properties, it can suppress transpiration from the food and maintain the freshness of the food. In addition, since the film also has oxygen barrier properties, especially in fruits and vegetables, aging due to respiration can be suppressed.

The coating does not necessarily cover the entire food, and may cover only a part of the food as long as it can suppress transpiration and respiration from the food.
For example, when the food is fruits and vegetables, the film may cover only a part of the fruits and vegetables. The area of the coating is preferably 10% or more, more preferably 25% or more, still more preferably 40% or more, and even more preferably 50% or more of the total surface area of the fruits and vegetables.
In addition, from the viewpoint of maintaining the freshness of fruits and vegetables, it is preferable that the coating coats at least a portion of the fruit or vegetable that evaporates a large amount of water. Sites where a large amount of water transpires include, for example, stomata on the underside of leaves, stems, stems, cobs, sepals, roots, and cut surfaces at the time of harvest.
Furthermore, from the viewpoint of maintaining the freshness of fruits and vegetables without significantly changing their appearance, it is preferable to cover only the portions where a large amount of water transpires.

[Food]
Foods to which the composition of the present invention can be applied include fresh foods such as fruits and vegetables, meat and fish, and processed foods such as dairy products and bakery products.
In particular, the film of the present invention is excellent in water vapor barrier properties, and is therefore preferably applied to fruits and vegetables or dairy products whose quality is likely to deteriorate due to transpiration. In addition, since the coating also has oxygen barrier properties, it is more preferable to apply it to fruits and vegetables that are subject to aging due to respiration.
Fruits and vegetables include, for example, citrus fruits such as apples, cherries, peaches, green plums, oranges, grapefruits, mandarin oranges, and sudachi, oysters, figs, strawberries, kiwifruits, grapes, blueberries, bananas, mangoes, melons, papaya, and lychee. (lychee), apricots, avocados, cantaloupes, guavas, nectarines, pears (Japanese pears, pears, etc.), plums; leaf and stem vegetables such as asparagus, cabbage, lettuce, spinach, Chinese cabbage, cauliflower, broccoli; fruit vegetables such as tomatoes, eggplants, pumpkins, green peppers and cucumbers; wild vegetables such as bracken and fern; Mycelium such as honshimeji mushrooms, enoki mushrooms and maitake mushrooms; and cut flowers such as chrysanthemums, roses and lilies.
Dairy products include cheese, butter and the like.

[Physical properties of film]
(average film thickness)
The average film thickness of the coating obtained from the composition of the present invention is preferably 0.1 μm or more and 10 μm or less, more preferably 0.5 μm or more and 5 μm or less. When the average film thickness is 0.1 μm or more, the water vapor barrier property and the oxygen barrier property are improved. On the other hand, when the average film thickness is 10 μm or less, the film can be formed while maintaining the texture of the food.
In the present invention, the thickness of the film may not be uniform over the entire food.
In addition, the average film thickness of the film is obtained by freeze-drying the food with the film in advance, peeling off the film, observing the cross section with an electron microscope or a metallurgical microscope, etc., and randomly selecting 10 points or more to measure the thickness. It can be obtained from the average value.

(Water vapor barrier property)
The film obtained from the composition of the present invention preferably has a water vapor transmission rate of 0.1 to 30 g/(m ² ·day) per 1 μm at 30° C. and 50% RH, and preferably 0.5 to 20 g/( m ² ·day) is more preferable, and 1 to 10 g/(m ² ·day) is even more preferable. When the water vapor transmission rate is within the above range, transpiration from food can be suppressed, and freshness can be maintained.
The water vapor transmission rate (WVTR) can be measured by a differential pressure method using a water vapor transmission rate measuring device DELTAPERM based on JIS K7129-5. More specifically, the measured value of the water vapor transmission rate when coated on a polyethylene terephthalate film having a thickness of 50 μm under the conditions of 30 ° C. and 50% RH is converted to the transmission rate per 1 μm by the following formula. be.

(Oxygen barrier property)
The coating of the present invention preferably has an oxygen permeability of 0.1 to 1000 cc/(m ² ·day·atm) per 1 μm at 25° C. and 50% RH, and preferably 0.5 to 700 cc/(m ² · day·atm), more preferably 1 to 500 cc/(m ² ·day·atm). When the oxygen permeability is within the above range, aging due to respiration of fruits and vegetables can be suppressed, and freshness can be maintained more.
The oxygen transmission rate (OTR) can be measured according to JIS K7126-2 by an isobaric method using an oxygen transmission rate measuring device OX-TRAN 2/21 (manufactured by MOCON). More specifically, the measured value of the oxygen permeability when coated on a polyethylene terephthalate film having a thickness of 50 μm under the conditions of 25° C. and 50% RH is converted into a permeability per 1 μm by the following formula. be.

<Method for producing coated food>
A coated food obtained by applying the composition of the present invention is produced by a method of applying the above composition to food. After applying the composition to the food, drying may be performed.
As for the application and drying of the composition, the method described in "Method for Forming Coating" described later can be suitably used.

<Coating method>
A method of forming a film according to the present invention includes a method of applying the above composition to food.
When the composition is applied to food, the method of application is not particularly limited. Injection method is mentioned.
Among these methods, the dipping method and the spraying method are preferable from the viewpoint of being able to relatively evenly coat the food surface having a three-dimensional shape.
In addition, when the food is fruit and vegetables, a film may be formed on the surface of the fruit and vegetables after harvesting, or a film may be formed on the surface of the fruit and vegetables before harvesting. good too. When the coating is formed before harvesting, it is desirable to form the coating when the fruits and vegetables reach a desired degree of maturity.

In this method, from the viewpoint of shortening the drying time of the composition and increasing the efficiency of the film-forming treatment, it is preferable to apply the composition to a portion of the food.
For example, when the food is fruits and vegetables, the composition may be applied only to a part of the fruits and vegetables. In this case, the coating area is preferably 10% or more, more preferably 25% or more, still more preferably 40% or more, and even more preferably 50% or more of the surface area of the whole fruits and vegetables.
Moreover, from the viewpoint of maintaining the freshness of fruits and vegetables, it is preferable to apply the composition at least to a portion where a large amount of water transpires.
From the viewpoint of minimizing the amount of sugar-based surfactant used, the composition may be applied only to areas where a large amount of water evaporates.

In this method, after the composition has been applied to the food product, a portion of the applied composition may be removed. Although the removal method is not particularly limited, removal by air pressure using an air dryer, or the like can be mentioned.
For example, by removing the excess composition from the surface of the food, it is possible to prevent poor drying of the portion to which an excessive amount was applied.
In addition, the amount of sugar-based surfactant used can be minimized by removing a portion of the composition from the food.
When the food is a fruit or vegetable, freshness can be maintained by covering at least the portion where a large amount of water is evaporated, so the composition in the other portion may be removed.
Regarding the coating method, there is an example described in "Coating Method" by Yuji Harasaki, published by Maki Shoten in 1979.

[Drying]
After applying the composition to the food, the coating may be dried for the purpose of removing the aqueous solvent. Drying methods include, for example, standing drying, air drying, and heat drying. From the viewpoint of maintaining the freshness of food, a method of standing and drying at room temperature (20 to 25 ° C.), or air drying at room temperature. A method is preferred.

<Method of shipping food>
The method for shipping food coated with the composition of the present invention includes (A) a step of conveying the food, (B) a step of forming a film on the food, and (C) a step of inspecting the food with the film using an evaluation device. , and in the step (B), it is preferable to form a film on the food by the method of forming a film according to the present invention. The food that has been coated and inspected in this way is shipped to the place of consumption by transportation or the like.
The order of the (B) step and the (C) step in the shipping method may be reversed. That is, the order of (A) step, (B) step, and (C) step may be sufficient, or the order of (A) step, (C) step, and (B) step may be used.
Below, the order of the (A) process, the (B) process, and the (C) process will be described in detail based on the image diagram shown in FIG. 1 as an example.

FIG. 1 is an image diagram of a food shipping method according to the present invention. (A) The step of conveying the food is a step of providing the food to the (B) step. The method is not particularly limited. For example, the food may be continuously conveyed by a belt conveyor or the like, or many foods may be collectively conveyed by a truck or the like.
FIG. 1 shows a mode in which food 10 is conveyed using belt conveyor 11 . The food 10 is placed on a belt conveyor and rotated by the rotating roll 12 to be subjected to the step (B).

The next step (B) is a step of forming a film on the food 10 conveyed in the step (A). For the formation of the coating, the method described in the above "Method for forming coating" can be suitably used.
FIG. 1 illustrates the immersion method, which is one of the preferred embodiments. The food 10 is immersed in an immersion bath 13 filled with the composition of the present invention, and the composition is applied to the surface of the food. The belt conveyor is provided with food fixing means such as claws, and the food 10 is carried into and out of the immersion tank in a fixed state. After that, the solvent is removed in the drying oven 14 to form a film on the food 10 . However, the drying oven 14 may be omitted, and the food 10 may be left standing at room temperature to dry, or drying may be omitted in solventless coating.

When the film is formed only on part of the food in the step (B), the composition is preferably applied or sprayed on the food 10 placed on the belt conveyor and conveyed to the drying oven 14.
Also, after only a portion of the food 10 is immersed in the immersion bath 13 by food gripping means such as a robot hand, it may be placed on the belt conveyor with the immersion surface facing up and conveyed to the drying furnace 14.

After the food 10 is immersed in the immersion bath 13, part of the applied composition may be removed by an air dryer (not shown) or the like.

Next, the (C) step is a step of inspecting the food 10 coated with the film in the (B) step using the evaluation device 15 . An optical sensor, a weight scale, a camera, or the like can be used as the evaluation device.
The inspection in the (C) inspection step includes various inspection items, but preferably includes at least one inspection selected from the group consisting of an appearance inspection, a sugar content inspection and a size inspection.
In addition, in the present invention, since the film has high transparency, it does not interfere with non-destructive inspection using light such as sugar content inspection, so the inspection method used for conventional foods ( For example, Japanese Unexamined Patent Application Publication No. 2012-78206) can be used as it is.

As described above, the coated foods that have undergone (A) the transporting step, (B) the coating forming step, and (C) the inspecting step are shipped by normal means. FIG. 1 shows an example of shipping by a shipping vehicle 16 .

Next, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples described below.

The following materials were blended in the amounts shown in Table 1 to prepare compositions of Examples 1-4, Comparative Examples 2-3 and Reference Examples 1-3. Specifically, the sugar-based surfactant (non-volatile component) is dissolved in an aqueous solvent consisting of ethanol and water at 73°C so that the content shown in Table 1 is obtained, and then dissolved at room temperature (25°C). for 2 hours to prepare a coating liquid (composition). The materials used are as follows.

S-1670; sucrose stearate, Mitsubishi Chemical Corporation "Ryoto (registered trademark) Sugar Ester", HLB about 16
P-1670; sucrose palmitate, Mitsubishi Chemical Co., Ltd. "Ryoto (registered trademark) sugar ester", HLB about 16
S-170; sucrose stearate, Mitsubishi Chemical Corporation "Ryoto (registered trademark) Sugar Ester", HLB about 1
O-170; sucrose oleate, Mitsubishi Chemical Corporation "Ryoto (registered trademark) Sugar Ester", HLB about 1
ER-290; sucrose erucate, Mitsubishi Chemical Corporation "Ryoto (registered trademark) sugar ester", HLB about 2
In Table 1, the content of sugar fatty acid esters having 3 or less fatty acid ester groups is indicated in the column of "low fatty acid ester", and the content of sugar fatty acid esters having 5 or more fatty acid ester groups is indicated in the "low fatty acid ester" column. It is described in the column of "high fatty acid ester". These contents are values obtained by calculation from the values of the number of fatty acid ester groups measured from each of the above products according to the METHOD OF ASSAY and the compounding ratio of each product.
In addition, the contents of "saturated fatty acid" and "unsaturated fatty acid" in Table 1 were calculated from the types of constituent fatty acids of each product, the number of fatty acid ester groups of each product, and the blending ratio of each product. value.

<Evaluation method>
(surface tension)
The surface tension of the composition is measured by the Wilhelmy method using a platinum plate at 25° C. using a surface tension meter (manufactured by Kyowa Interface Science Co., Ltd.: high-performance surface tension meter DyneMaster “DY-500”). gone. The measurement was performed 3 times and the average value was obtained.

(Defoaming time)
15 mL of the composition was placed in a 50 mL glass bottle, and the glass bottle was vigorously shaken up and down 10 times under the condition of 25° C. to generate bubbles on the upper surface of the composition. Looking at the glass bottle from above, the time until bubbles disappeared and the liquid level was confirmed was measured. The shorter the defoaming time, the less likely it is that traces of foam will remain even after drying when foam is generated due to liquid transfer or the like in the coating process. In Examples 3 and 4, bubbles disappeared immediately after shaking the glass bottle, so "<1" is indicated.

(drying speed)
The coating solutions (compositions) of Examples 1 to 4, Comparative Examples 2 to 3, and Reference Examples 1 to 3 were applied to strawberries by an immersion method, and the time required for drying under the conditions of a temperature of 25 ° C. and a humidity of 25% RH. It was confirmed. Whether or not drying was completed was judged by the presence or absence of stickiness when the surface was touched with a finger. That is, it was assumed that drying was completed when there was no stickiness.

(Appearance of coating film)
The appearance of the strawberries subjected to the drying rate test was visually evaluated. Evaluation criteria are as follows.
A (very good): less than 5% of fruit with traces of application left or whitened surface.
B (good): 5% or more and less than 50% of fruits with traces of application or whitening on the surface.
C (poor): More than 50% of the fruits have left traces of application or have whitened surfaces.

[Oxygen barrier property evaluation]
The coating liquids (compositions) of Examples 1 to 4, Comparative Examples 2 to 3, and Reference Examples 1 to 3 were coated on a PET film (50 μm thick, manufactured by Toyobo Co., Ltd.: A4160 type) whose highly smooth side had been corona-treated in advance with #20. It was applied with a bar coater and dried at room temperature (20 to 25° C.) for 24 hours to form a coating film on the PET film.
For the coated PET films of Examples 1 to 4, Comparative Examples 2 to 3, and Reference Examples 1 to 3, an oxygen permeability measuring device "OX-TRAN 2/21" manufactured by MOCON was measured based on JIS K7126-2. was used to measure the oxygen permeability under conditions of 25° C. and 50% RH, and the oxygen permeability per 1 μm of the coating film was obtained by the following formula.

[Evaluation of water vapor barrier properties]
The coated PET films of Examples 1 to 4, Comparative Examples 2 to 3, and Reference Examples 1 to 3, which were produced in the same manner as in the evaluation of the oxygen barrier property, were tested for water vapor permeability manufactured by Technolox based on the JIS K7129-5 method. Using a rate measuring device DELTAPERM, the water vapor transmission rate was measured under the conditions of 30° C. and 50% RH, and the water vapor transmission rate per 1 μm of the coating film was obtained by the following formula.

(Weight maintenance rate)
Examples 1 to 4, Comparative Examples 2 to 3 and Reference Example 2 Coated grapes (compositions) applied by immersion method, and Comparative Example 1 grapes (no coating) before storage (0 days) Based on the weight of grapes, the weight maintenance rate after storage at 12 ° C., 80% RH for 5, 12, and 24 days ((weight after storage / weight on day 0) × 100 (%)) rice field.

From the results in Table 1, the coating liquids (compositions) of Examples having a surface tension of 34 mN/m or less have a short defoaming time and a fast drying speed, so that traces of coating remain or the surface is whitened. The number of fruits that were covered was very small, less than 5%, and the coating appearance was very good. In addition, the coatings made of the compositions of Examples 1 to 4 have oxygen barrier properties and water vapor barrier properties, and were able to suppress transpiration from grapes more than Comparative Example 1, so they have sufficient freshness retention performance. It was suggested that
On the other hand, the coating liquid (composition) of the comparative example has a long defoaming time and a slow drying speed, so that the number of fruits that have left coating marks or have whitened surfaces is 5% or more and less than 50%. or 50% or more, and the coating appearance was greatly inferior to that of the examples.

1 Food Shipping System 10 Food 11 Belt Conveyor 12 Rotating Roll 13 Immersion Tank 14 Drying Furnace 15 Evaluation Device 16 Shipping Vehicle

Claims (22)

A composition comprising a sugar-based surfactant and an aqueous solvent and having a surface tension of 34 mN/m or less at 25°C. 2. The composition according to claim 1, wherein the main component of said sugar-based surfactant is a sugar fatty acid ester. 3. The composition according to claim 2, wherein the saturated fatty acid and the unsaturated fatty acid have a mass ratio of 50/50 to 99/1 among the fatty acids constituting the sugar fatty acid ester. 4. The composition according to claim 2, comprising 50 to 98% by mass of sugar fatty acid ester having 3 or less fatty acid ester groups out of 100% by mass of said sugar fatty acid ester. The composition according to any one of claims 2 to 4, comprising 2 to 50% by mass of a sugar fatty acid ester having 5 or more fatty acid ester groups out of 100% by mass of the sugar fatty acid ester. The composition according to any one of claims 1 to 5, wherein the non-volatile component concentration in the composition is 0.1% by mass or more and 20% by mass or less. The composition according to any one of claims 1 to 6, wherein the content of the sugar-based surfactant is 60 mass% or more of the non-volatile components in the composition. The composition according to any one of claims 1 to 7, wherein the aqueous solvent is water or a mixture of water and alcohol. 9. The composition according to claim 8, wherein the alcohol content is 1% by mass or more and 30% by mass or less. The composition according to any one of claims 1 to 9, which is for coating on fruits and vegetables. A film-coated food having a film comprising the composition according to any one of claims 1 to 9. 11. The coated food product according to claim 10, wherein the food product is a fruit or vegetable. A method for producing a film-coated food, comprising the step of applying the composition according to any one of claims 1 to 9 to the food. 14. The method for producing a film-coated food according to claim 13, wherein the coating method is a dipping method or a spraying method. 15. The method for producing a film-coated food according to claim 13 or 14, wherein the composition or the sugar-based surfactant is applied to a portion of the food. 15. The method for producing a film-coated food according to claim 13 or 14, wherein after applying the composition to the food, part of the applied composition is removed. A method of forming a coating, comprising the step of applying the composition according to any one of claims 1 to 9 to food. 18. The film forming method according to claim 17, wherein the coating method is a dipping method or a spraying method. 19. The method of forming a film according to claim 17 or 18, wherein the composition is applied to a portion of food. 19. The method of forming a film according to claim 17 or 18, wherein after applying the composition to food, a portion of the applied composition is removed. A food shipping method comprising (A) a step of conveying food, (B) a step of forming a film on food, and (C) a step of inspecting the food with a film using an evaluation device, wherein the (B ), a method for shipping food, wherein the film is formed by the method according to any one of claims 17 to 20. 22. The food shipping method according to claim 21, wherein said (C) inspection step includes at least one inspection selected from the group consisting of an appearance inspection, a sugar content inspection and a size inspection.

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