Method for curing vanilla beans and method for manufacturing cured vanilla beans

Abstract

The present invention has the objective of providing a method that uses less labor to obtain cured vanilla beans having a high vanilla content, which is the most important flavor component, while minimizing the risk of spoilage by microorganisms. The present invention relates to a method, for curing vanilla beans, having a step for either sterilizing green vanilla beans and then filling a bag with the green vanilla beans or filling the bag with the green vanilla beans and then sterilizing the green vanilla beans, and a step for sealing the bag and then performing drying.

Description

Method for curing vanilla beans and method for producing cured vanilla beans

[0001] The present invention relates to a method for curing vanilla beans and a method for producing cured vanilla beans.

[0002] Vanilla beans are the fruit of the Vanilla genus of the Orchidaceae family. Immediately after harvest, green vanilla beans have almost no scent, but as they ripen, many aromatic compounds, primarily vanillin, are produced, resulting in vanilla beans with a unique sweet aroma. However, if the fruit is left to ripen naturally, there is a risk of the fruit rotting due to microorganisms. Furthermore, as the fruit ripens, the pod splits, splitting in two. This causes the aromatic compounds produced in the split part to evaporate and decrease in volume, and there is also the problem of a decline in quality due to oxidation.

[0003] To prevent these problems, commercial producers use a process called curing, in which green vanilla beans immediately after harvest undergo cell destruction treatments such as hot water immersion or freezing and thawing, followed by repeated fermentation and drying. The most widely used traditional curing method involves immersing green vanilla beans in hot water at 55–80°C for 10 seconds to 4 minutes, wrapping the warm beans in cloth, and keeping them warm for 24–48 hours. Next, the beans are sun-dried for 2–5 hours, then wrapped in cloth and stored until the next day, a process repeated for 1–3 weeks. They are then dried in a well-ventilated room for 1–2 months. Finally, they are placed in a container such as a wooden box and stored for 2–3 months to mature, resulting in cured vanilla beans. The entire curing process takes 5–6 months to complete.

[0004] During this curing process, glucovanillin contained in vanilla beans reacts with β-glucosidase also contained in vanilla beans to produce vanillin. Vanillin is the absolute indicator of the quality of cured vanilla beans, and the higher the quality and value of cured vanilla beans, the higher the vanillin concentration. Cured vanilla beans are used as they are as an ingredient in confectioneries and cosmetics, and are also widely used as an ingredient in natural flavorings such as vanilla extract.

[0005] As mentioned above, traditional curing methods require a great deal of effort. Furthermore, the conditions for each process, such as the temperature of the hot water, the soaking time, and the timing of the transition from sun drying to shade drying, are heavily dependent on experience, which ultimately contributes to inconsistent quality. Microbial contamination can occur during the long process, resulting in a deterioration in quality. Therefore, frequent checks for microbial contamination are required at each process, which contributes to the complexity of the work. Furthermore, as can be seen from the sweet aroma that fills the air at the site where the drying process is carried out, some of the vanillin produced volatilizes and is lost.

[0006] To solve these problems, various efforts have been made to improve the process. For example, Patent Document 1 describes a curing method in which vanilla beans are placed in a partially resealable, breathable container, and the container is opened and closed in a sterile environment, thereby reducing the risk of microbial contamination during the process and in the product.

[0007] Furthermore, Non-Patent Document 1 describes a curing method that significantly shortens the manufacturing period by drying in a dryer set at 50°C instead of time-consuming sun drying.

[0008] Japanese Patent Application Publication No. 2011-26431

[0009] Anuradha, Krushnamurthy, Bellur Nanjundaiah Shyamala, and Madeneni Madhava Naidu. “Vanilla-Its science of cultivation, curing, chemistry, and nutraceutical properties.” Critical reviews in food science and nutrition 53.12 (2013): 1250-1276.

[0010] However, the technology described in Patent Document 1 requires the lid to be opened and closed in a sterile environment at the beginning of the drying process, and requires equipment to create a sterile environment and regular operations in that environment, which poses problems in terms of cost and workload.

[0011] Furthermore, the technique described in Non-Patent Document 1 has the problem that the cost of installing a dryer for drying all of the harvested vanilla beans is extremely expensive for producers, and the problem that the cured vanilla beans obtained by this method have a distinctive cooked odor.

[0012] The present invention has been made in view of the above-mentioned conventional circumstances, and an object to be achieved by the present invention is to provide a method for obtaining cured vanilla beans having a high content of vanillin, the most important aroma component, in a labor-saving manner while suppressing the risk of spoilage due to microorganisms.

[0013] As a result of intensive research into solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by sterilizing green vanilla beans before filling them into bags, or by filling green vanilla beans into bags, sterilizing them, and then drying them in a sealed state in the bag, and have thus completed the present invention.

[0014] That is, the present invention relates to the following items <1> to <7>. <1> A method for curing vanilla beans, comprising the steps of sterilizing green vanilla beans and then filling them into bags, or sterilizing green vanilla beans after filling them into bags, and sealing the bags and then drying them. <2> The method for curing vanilla beans according to <1>, wherein the bag has a water vapor transmission rate of 0.3 g / day or more at 40°C and a relative humidity of 90% per bag. <3> The method for curing vanilla beans according to <1> or <2>, wherein the value obtained by dividing the fresh weight (g) of vanilla beans to be filled into the bag by the water vapor transmission rate (g / day) per bag is 55 or less. <4> The method for curing vanilla beans according to any one of <1> to <3>, wherein the green vanilla beans are not subjected to cell disruption treatment. <5> The method for curing vanilla beans according to any one of <1> to <4>, further comprising a step of drying the green vanilla beans at 10°C to 50°C after sealing the bags. <6> The method for curing vanilla beans according to any one of <1> to <5>, wherein the sterilization treatment is carried out under conditions that do not inactivate β-glucosidase present in the green vanilla beans. <7> A method for producing cured vanilla beans, comprising the method for curing vanilla beans according to any one of <1> to <6>.

[0015] According to the present invention, it is possible to provide a labor-saving method for obtaining cured vanilla beans having a high content of vanillin, the most important aroma component, while suppressing the risk of spoilage by microorganisms.

[0016] The present invention will be described in detail below, but these are examples of preferred embodiments, and the present invention is not limited to these details. In this specification, proportions (percentages, parts, etc.) based on weight are the same as proportions (percentages, parts, etc.) based on mass.

[0017] [Method for curing vanilla beans] The method for curing vanilla beans of the present invention includes a step of sterilizing green vanilla beans and then packing them into a bag, or a step of packing green vanilla beans into a bag and then sterilizing them, and a step of sealing the bag and then drying it.

[0018] The vanilla plants from which the vanilla beans used in the present invention can be harvested are not particularly limited as long as they are varieties that produce vanillin. Examples include Vanilla planifolia, Vanilla xtahitensis, Vanilla pompona, and hybrids thereof. Harvesting is preferably carried out 8 to 10 months after pollination, when the color of the pods begins to change from green to yellowish. Curing is preferably carried out promptly after harvesting, but green vanilla beans that have been harvested for a certain period of time may be used as long as they are not spoiled.

[0019] The fresh weight of each green vanilla bean used in the curing method of the present invention may be 5 to 40 g, and the dry weight may be 0.5 to 10 g. Furthermore, the dry solids content of each green vanilla bean used in the curing method of the present invention may be 10 to 25% by mass, and the moisture content may be 90 to 75% by mass. The fresh weight of vanilla beans is the weight of vanilla beans containing moisture. The dry weight of vanilla beans is the weight of vanilla beans after moisture has been removed. The dry solids content of vanilla beans is the value obtained by dividing the dry weight by the fresh weight and multiplying the result by 100. The moisture content of vanilla beans is the value obtained by subtracting the dry weight divided by the fresh weight from 1 and multiplying the result by 100. These values ​​can be measured, for example, by the method described in the Examples below.

[0020] The green vanilla beans are sterilized to prevent microbial proliferation and spoilage during the long-term curing process. Sterilization methods include sterilization by heat such as hot water immersion, flame sterilization, and low-temperature heating; sterilization with chemicals such as ethanol, sodium hypochlorite, peracetic acid preparations, ozone water, and acidic electrolyzed water; sterilization by electromagnetic waves such as ultraviolet light, microwaves, and gamma rays; and supercritical carbon dioxide sterilization. There are no particular limitations on the method, as long as it provides a sterilizing effect. Furthermore, multiple sterilization methods may be selected and combined from these methods.

[0021] However, because sterilization by hot water immersion transmits heat to the interior of green vanilla beans, depending on the conditions, it may result in the inactivation of enzymes inherent in vanilla beans, such as β-glucosidase, which is important for aroma production during curing. Therefore, it is preferable to perform the sterilization treatment under conditions that do not inactivate the β-glucosidase present in green vanilla beans. To prevent complete inactivation of the enzymes, when sterilization by hot water immersion is performed, it is desirable to perform the treatment for less than 10 minutes if the hot water temperature is less than 60°C, less than 8 minutes if the hot water temperature is 60°C or higher but less than 70°C, less than 5 minutes if the hot water temperature is 70°C or higher but less than 80°C, and less than 2 minutes if the hot water temperature is 80°C or higher but less than 90°C.

[0022] The harvested green vanilla beans may be used in their entirety, or, to further reduce the risk of microbial contamination, two areas of the green vanilla beans that are likely to be routes of entry for microorganisms, the petal side and the rachis side, may be cut off before or after sterilization treatment. The length of the cut off area is not particularly limited, but for example, 3 mm to 10 mm may be cut off at each end.

[0023] The sterilization treatment is preferably carried out immediately before the green vanilla beans are filled into bags, or after the green vanilla beans have been filled into bags.

[0024] Green vanilla beans may be subjected to cell disruption treatment before or after pasteurization, which not only prevents pod cracking during curing but also promotes the association of β-glucosidase with glucovanillin, thereby increasing the efficiency of vanillin production.

[0025] Examples of cell disruption treatments include a hot water immersion treatment in which green vanilla beans are immersed in hot water at 55°C to 80°C for approximately 10 seconds to 4 minutes; a sun heating treatment in which green vanilla beans are spread out on a black cloth or tray and exposed to sunlight for several days; an oven heating treatment in which green vanilla beans are bundled, wrapped in cloth, and heated in an oven at 60°C for 36 to 48 hours; and a freeze-thaw treatment in which green vanilla beans are frozen by immersing them in a freezer at 0°C to -80°C for two hours or more or in liquid nitrogen at -196°C for approximately five minutes, and then kept at room temperature or in a refrigerated condition, or thawed by immersing them in water.

[0026] When sterilization is performed by immersion in hot water, the temperature and time conditions overlap, so that sterilization and cell disruption can be performed at the same time.

[0027] However, in the present invention, vanilla beans are packed in a bag and cured in a sealed state, so that the volatilization of aroma components due to pod cracking and the deterioration of quality due to oxidation are unlikely to occur. Therefore, the method of the present invention does not require the vanilla beans to be subjected to cell destruction treatment.

[0028] In the present invention, vanilla beans are either sterilized before being packed into bags, or sterilized after being packed into bags with vanilla beans. The bags filled with vanilla beans are preferably sealed without any gaps to prevent the intrusion of microorganisms. Heat sealing, zippers, adhesive tape, etc. can be used as sealing means, but sealing without any gaps is preferred to prevent the intrusion of microorganisms. Furthermore, after sealing, it is preferable not to open the bags until curing is complete.

[0029] The material of the bag used in the present invention is not particularly limited, but examples include polyethylene such as low-density polyethylene and high-density polyethylene, polypropylene, polyethylene terephthalate, polystyrene, nylon, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymer, polybutylene succinate, polybutylene succinate adipate or polylactic acid, cellophane, rayon, polyester, acrylic, pulp, wool, cotton, etc. Bags formed using a film of any of these materials alone may be used, or bags formed using a multi-layer film composed of multiple materials may be used. Also, bags formed using two different types of film on the front and back may be used.

[0030] It is also possible to use materials in which the gas permeability has been adjusted by opening micropores in these materials using a laser or needle. Materials whose anti-fogging properties have been enhanced by applying a surfactant or the like to the film surface or by kneading it into the film during production may also be used. These materials may be formed into a film and sealed tightly with heat sealing or the like to form a bag.

[0031] In order to cure vanilla beans sealed in a bag, it is necessary to remove the moisture contained in the vanilla beans. When vanilla beans are sealed in a bag, the higher the water vapor transmission rate of the bag, the faster the moisture is removed. Therefore, it is preferable that the bag used in the present invention has a water vapor transmission rate of at least a certain level. The preferred value of the water vapor transmission rate of the bag varies depending on the temperature and humidity at which drying is performed, and the amount of vanilla beans packed in the bag, so it cannot be generally defined, but the water vapor transmission rate per bag at 40°C and a relative humidity of 90% is preferably 0.3 g / day or more, and more preferably 0.8 g / day or more per bag.

[0032] Furthermore, the value obtained by dividing the fresh weight (g) of green vanilla beans to be packed into a bag by the water vapor transmission rate (g / day) of the bag is preferably 55 or less, and more preferably 20 or less. This value obtained by dividing the fresh weight of green vanilla beans to be packed by the water vapor transmission rate of the bag indicates an estimate of the number of days required for water vapor equivalent to the fresh weight of the green vanilla beans to permeate through the bag. Drying of green vanilla beans is also affected by other factors, such as the time required for moisture to escape from the vanilla bean tissue, the time required for evaporation, differences in drying environment, and the dry solids content of the fresh weight. Therefore, this value is a guideline for determining the optimal amount of green vanilla beans to be packed into a bag. When multiple green vanilla beans are packed into one bag, it is preferable to satisfy this value.

[0033] The water vapor permeability of the bag can be measured by the method described in JIS K 7129-4:2006.

[0034] The amount of vanilla beans to be filled into the bag is determined appropriately depending on the size and properties of the bag.

[0035] The vanilla beans packed into the bag are sealed and kept for a certain period of time to dry out. They can be kept indoors or outdoors as long as they are protected from rain.

[0036] The drying process can be performed indoors under temperature control or using dedicated drying equipment such as an oven. The optimal temperature for the drying process cannot be generally defined, but it is, for example, 10°C to 80°C, preferably 10°C to 70°C, more preferably 25°C to 60°C, and even more preferably 25°C to 50°C. For example, the drying temperature may be 10°C to 50°C. The higher the drying temperature, the shorter the drying period. However, if the temperature at the beginning of the drying process is higher than 50°C, the activity of β-glucosidase may be inactivated, potentially reducing the amount of vanillin produced. To prevent this and shorten the drying period, the drying temperature may be changed during the drying process. For example, one possible method is to dry the product at 25°C for two weeks and then at 80°C. The drying time is, for example, 1 week to 48 weeks, preferably 1 week to 30 weeks, more preferably 1 week to 24 weeks, and even more preferably 1 week to 12 weeks. The drying time may be 2 weeks to 48 weeks or 4 weeks to 30 weeks.

[0037] The moisture content of the vanilla beans is used as a guideline for the endpoint of drying, and generally, vanilla beans with a high vanillin content have a high moisture content at the endpoint of drying, while vanilla beans with a low vanillin content have a low moisture content at the endpoint of drying. For this reason, the moisture content of the vanilla beans at the endpoint of drying cannot be specified in general, but is preferably 10% to 65% by mass, and more preferably 15% to 50% by mass. The moisture content of vanilla beans is defined as above. The moisture content of vanilla beans can be measured, for example, by the method described in the Examples below.

[0038] The fresh weight of each cured vanilla bean after the drying step may be 0.6 to 26 g, and the dry weight may be 0.5 g to 10 g. The dry solids content of each cured vanilla bean after the drying step may be 35 to 90 mass %. The definitions of the fresh weight, dry weight, and dry solids content of vanilla beans are as described above. The fresh weight, dry weight, and dry solids content of vanilla beans can be measured, for example, by the method described in the Examples below.

[0039] The vanillin yield of the vanilla bean curing method of the present invention is preferably 40% or more, and more preferably 70% or more. The vanillin yield is calculated by dividing the vanillin content per dry weight of cured vanilla beans after the curing step by the vanillin potential per dry weight of the green vanilla beans, where the vanillin content is defined as the vanillin content when all of the glucovanillin in the green vanilla beans before curing is converted to vanillin, and multiplying the result by 100. The vanillin concentration per unit weight and the vanillin yield can be measured, for example, by the methods described in the Examples below.

[0040] After the drying process, the vanilla beans are stored in the bag at room temperature, in a refrigerator, or in a freezer until use. An additional aging process may also be performed.

[0041] [Method for Producing Cured Vanilla Beans] The method for producing cured vanilla beans of the present invention comprises the above-described method for curing vanilla beans of the present invention.

[0042] The cured vanilla beans obtained by the present invention can be used in the same manner as conventional ones for the same purposes, including as browned dried fruit (so-called vanilla beans) and as vanilla extract obtained by extraction using water, alcohol, propylene glycol, etc.

[0043] The cured vanilla beans obtained by the present invention can be used in a variety of ways, for example, as a raw material for foods and beverages, including beverages, frozen desserts such as ice creams, sherbets, and popsicles, luxury items such as Japanese and Western confectioneries, chewing gums, chocolates, breads, and coffee, and various snacks.

[0044] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples in any way.

[0045] First, the methods for measuring the content of each component and the physical properties of the composition, the method for measuring the water vapor transmission rate of the bag, and the method for evaluating the vanillin yield will be described. The results of each example are shown in Table 1.

[0046] <Method for measuring dry solid content and moisture content> The dry solid content and moisture content of vanilla beans were determined by drying the vanilla beans to remove moisture and measuring the mass of the remaining solid matter. The specific measurement method was as follows.

[0047] The mass of the metal weighing dish was measured and designated as W1 (g). Next, after immersion in liquid nitrogen for 5 minutes, approximately 3 g of vanilla beans finely pulverized using a Yasui Kikai Multi-Beads Shocker MB3200 was added, and the total mass was measured and designated as W2 (g). After drying for 3 hours in a dryer set at 105°C, it was cooled in a desiccator and the total mass was measured and designated as W3 (g). The dry solid content and moisture content were calculated using Equation 1 and Equation 2, respectively. Equation 1: Dry solid content (mass%) = (W3 - W1) ÷ (W2 - W1) × 100 Equation 2: Moisture content (mass%) = {1 - (W3 - W1) ÷ (W2 - W1)} × 100

[0048] <Method for Quantifying Vanillin and Glucovanillin> The concentrations of vanillin and glucovanillin in vanilla beans were measured by extracting crushed vanilla beans with a solvent and then measuring them by liquid chromatography. The specific measurement method was as follows. After immersing in liquid nitrogen for 5 minutes, 1 g of vanilla beans was finely crushed using a Yasui Kikai Multi-Beads Shocker MB3200 and placed in a 100 ml measuring flask. 60% by volume ethanol was added, and extraction was performed for 2 hours in a 65°C water bath while stirring with a stirrer bar. After cooling to room temperature, the stirrer bar was removed, and the mixture was diluted to 100 ml with 60% by volume ethanol. The mixture was passed through a 0.45 μm filter, filled into a vial, and measured by liquid chromatography. Vanillin (Nacalai Tesque) and vanillin-4-O-β-D-glucoside (Sigma-Aldrich) were used as reference samples.

[0049] The liquid chromatography analysis conditions were as follows. Apparatus: Agilent 1200 series (Agilent Technologies Inc.) Mobile phase: Solution A - 0.1% formic acid, Solution B - acetonitrile Column: Inertsil sustain C18 (5 μm, 4.6 mm×150 mm) (GL Sciences Inc.) Flow rate: 1.0 ml / min Gradient: A / B = 97 / 3 passed for 1 minute, then passed to become 25 / 75 over 25 minutes Detector: Diode array detector Measurement wavelength: 260 nm The obtained vanillin concentration per fresh weight of the vanilla beans was divided by the dry solids content of the vanilla beans and multiplied by 100 to determine the vanillin concentration per dry weight.

[0050] <Measurement of Water Vapor Transmission Rate> The water vapor transmission rate was measured in accordance with JIS K 7129-4:2006. A gas / water vapor transmission rate measuring device GTR-10X manufactured by GTR Tech Co., Ltd. was used. Gas chromatography was used as the detector, and the measurement environment was 40°C and a relative humidity of 90%. The obtained water vapor transmission rate per unit area (g / m ２ The water vapor transmission rate per bag (g / day·bag) was calculated by multiplying the water vapor transmission rate (g / day·bag) by the surface area of ​​the bag. For two-sided bags, three-sided bags, and palm-shaped bags, the surface area of ​​the two bags (front and back) was included, and for stand-up packs and gusset bags, the surface area of ​​the gusset was also included.

[0051] <Method for evaluating vanillin yield> The vanillin content when all of the glucovanillin in green vanilla beans is converted to vanillin is defined as the vanillin potential, and the vanillin yield is calculated by dividing the vanillin content per dry weight of cured vanilla beans by the vanillin potential per dry weight of green vanilla beans and multiplying the result by 100. The curing methods were evaluated based on the vanillin yield.

[0052] However, if green vanilla beans are crushed and the components extracted to analyze their vanillin potential, cured vanilla beans cannot be obtained from those green vanilla beans. Therefore, the average vanillin potential of green vanilla beans of the same degree of maturity as the green vanilla beans used for curing was used. The degree of maturity can be determined, for example, from the period from pollination to harvest or the color of the vanilla bean pod. The specific procedure for calculating the average vanillin potential is as follows.

[0053] A single green vanilla bean (Vanilla planifolia) with a yellowish pod was immersed in liquid nitrogen for 5 minutes and finely pulverized using a Yasui Kikai MB3200 Multi-Beads Shocker. The finely pulverized sample was used to measure the dry solids content of the green vanilla bean and the vanillin and glucovanillin concentrations per fresh weight of the green vanilla bean. The resulting glucovanillin concentration (mg / g FW) was multiplied by the ratio of the molecular weights of vanillin and glucovanillin (152.15 / 314.29) to determine the vanillin equivalent of glucovanillin. The vanillin potential (mg / g FW) per fresh weight of the green vanilla bean was calculated by adding the vanillin concentration to this. The vanillin potential per fresh weight of the green vanilla beans was divided by the dry solids content of the green vanilla beans and multiplied by 100 to obtain the vanillin potential per dry weight of the green vanilla beans (mg / g DW). The same procedure was performed on 50 green vanilla beans in the same condition, and the average vanillin potential per dry weight of the obtained green vanilla beans was 69.6 mg / g DW.

[0054] The vanillin yield can be calculated from the average value of the vanillin concentration per dry weight of the cured vanilla beans and the vanillin potential per dry weight of the green vanilla beans using the following formula 3: Vanillin yield (%) = Vanillin concentration per dry weight of the cured vanilla beans (mg / g DW) ÷ 69.6 (mg / g DW) × 100

[0055] Example 1: One green vanilla bean of Vanilla planifolia, with the pod color tinged with yellow, was placed in a -20°C freezer for 48 hours and completely frozen to the center. Next, 5 mm portions were cut off from both ends of the vanilla bean, and the vanilla bean was weighed to obtain FW1. After measuring the weight, the vanilla bean was placed in a 0.1% by mass aqueous solution of sodium hypochlorite. After stirring for 5 minutes to sterilize, the vanilla bean was placed in a colander and washed with running water for 5 minutes to remove the sodium hypochlorite. After draining the liquid on the colander for 1 minute, the vanilla bean was placed in 5 L of 80% by volume ethanol.

[0056] The vanilla beans were immersed for 1 minute to sterilize, then transferred to a colander and drained for 1 minute. Next, the vanilla beans were filled into a three-sided polypropylene bag measuring 150 mm in length, 200 mm in width, and 20 μm thick, and the opening was sealed with a heat sealer. The bag was placed in an incubator (LTE-510, manufactured by Tokyo Rikaki Co., Ltd.) set at 25°C and dried until the weight of the vanilla beans was 30% of FW1 or for 168 days, whichever was shorter. Cured vanilla beans were thus obtained. The weight of the cured beans was measured and designated as FW2.

[0057] Example 2 Cured vanilla beans were obtained in the same manner as in Example 1, except that a three-sided bag made of low-density polyethylene, 150 mm long, 200 mm wide and 40 μm thick, was used.

[0058] Example 3 Cured vanilla beans were obtained in the same manner as in Example 1, except that a three-sided bag made of low-density polyethylene, 150 mm long, 200 mm wide and 20 μm thick, was used.

[0059] Example 4 Cured vanilla beans were obtained in the same manner as in Example 1, except that a three-sided bag made of high-density polyethylene, measuring 150 mm in length, 200 mm in width, and 6 μm in thickness, was used.

[0060] Example 5 Cured vanilla beans were obtained in the same manner as in Example 1, except that a three-sided bag made of a nylon / ethylene-vinyl alcohol copolymer multilayer film measuring 150 mm in length, 210 mm in width and 45 μm in thickness was used.

[0061] Example 6 Cured vanilla beans were obtained in the same manner as in Example 1, except that a three-sided bag made of ethylene-vinyl alcohol copolymer, measuring 150 mm in length, 210 mm in width and 30 μm in thickness, was used.

[0062] Example 7 Cured vanilla beans were obtained in the same manner as in Example 1, except that a three-sided bag made of polyethylene terephthalate, 120 mm long, 220 mm wide and 32 μm thick, was used.

[0063] Example 8 Cured vanilla beans were obtained in the same manner as in Example 1, except that a nylon three-sided bag measuring 150 mm in length, 210 mm in width, and 15 μm in thickness was used.

[0064] Example 9 Cured vanilla beans were obtained in the same manner as in Example 1, except that a three-sided bag made of polylactic acid, 150 mm long, 210 mm wide and 25 μm thick, was used.

[0065] Example 10 Cured vanilla beans were obtained in the same manner as in Example 1, except that a three-sided polypropylene bag measuring 150 mm in length, 200 mm in width, and 30 μm in thickness was used.

[0066] Example 11 Cured vanilla beans were obtained in the same manner as in Example 1, except that a three-sided bag made of a nylon / ethylene-vinyl alcohol copolymer / nylon / polyethylene multilayer film measuring 150 mm in length, 200 mm in width, and 80 μm in thickness was used.

[0067] Example 12 Cured vanilla beans were obtained in the same manner as in Example 1, except that the temperature of the incubator was set to 40°C.

[0068] Example 13 Cured vanilla beans were obtained in the same manner as in Example 1, except that the temperature of the incubator was set to 50°C.

[0069] Example 14 Cured vanilla beans were obtained in the same manner as in Example 1, except that green vanilla beans were used without freezing.

[0070] Example 15 Cured vanilla beans were obtained in the same manner as in Example 9, except that green vanilla beans were used without freezing.

[0071] Example 16 Cured vanilla beans were obtained in the same manner as in Example 1, except that the temperature of the incubator was set to 60°C.

[0072] Comparative Example 1 Cured vanilla beans were prepared according to a traditional curing method. Green vanilla beans were weighed and then immersed in 60°C hot water for 2 minutes. After immersion, they were quickly placed in a glass beaker, sealed with plastic wrap, and then kept warm for 48 hours in an incubator (LTE-510, manufactured by Tokyo Rikaki Co., Ltd.) set at 50°C. Next, the vanilla beans were placed on a Kimtowel and dried in the sun for 4 hours, then wrapped in the Kimtowel and stored in a cool, dark place until the next day. This process was repeated for 3 weeks. Next, the vanilla beans were placed on a Kimtowel and dried in the shade for 10 hours, then wrapped in the Kimtowel and stored in a cool, dark place until the next day. This process was repeated for 8 weeks. After drying in the shade, the vanilla beans were wrapped in wax paper and stored in a cool, dark place for 2 months. In this way, cured vanilla beans were obtained.

[0073] Examples 1 to 16 and Comparative Example 1 were all carried out three times, and the vanillin yield of the resulting cured vanilla beans was determined and evaluated. The evaluation results are shown in Table 1.

[0074]

[0075] The results in Table 1 show that the vanillin yields of Examples 1 to 16 are higher than the vanillin yield of Comparative Example 1, which was carried out using the traditional curing method.

[0076] In evaluating cured vanilla beans, the vanillin concentration is an absolute index, and the higher the quality of the cured vanilla beans, the higher the vanillin concentration, and conversely, the lower the vanillin concentration, the lower the quality. The vanillin concentrations of 30.5 mg / g DW to 60.9 mg / g DW obtained in Examples 1 to 16 this time are 1.5 to 3 times higher than those of Madagascar vanilla beans, which are considered to be of high quality, and very high-quality vanilla beans were obtained.

[0077] Furthermore, in all of Examples 1 to 16, no spoilage due to mold, yeast, or bacteria was observed in the vanilla beans or cured vanilla beans during the process. This shows that the sterilization step performed when the beans are packed into bags prevents mold growth in subsequent steps, even without sterilization by sun exposure or ultraviolet light, which also serves as drying. Thus, the method of the present invention makes it possible to obtain cured vanilla beans with a high vanillin concentration with an extremely small amount of work.

[0078] In Examples 14 and 15, green vanilla beans were cured without cell disruption treatment such as freezing or hot water immersion, and yet cured vanilla beans with a high vanillin concentration were obtained. According to the present invention, high-quality cured vanilla beans can be obtained without the loss of vanillin during curing, even without cell disruption treatment.

[0079] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the present invention. This application is based on a Japanese patent application (Patent Application No. 2021-142372) filed on September 1, 2021, the entirety of which is incorporated by reference. All references cited herein are incorporated in their entirety.

Claims

1. A step of filling the bag after subjecting green vanilla beans to a sterilization treatment or subjecting the bag filled with green vanilla beans to a sterilization treatment, and A step of drying after sealing the bag A method for curing vanilla beans having the above steps.

2. The method for curing vanilla beans according to Claim 1, wherein the water vapor transmission rate per bag at 40°C and a relative humidity of 90% of the bag is 0.3 g / day or more.

3. The method for curing vanilla beans according to Claim 1 or 2, wherein the value obtained by dividing the fresh weight (g) of the vanilla beans filled in the bag by the water vapor transmission rate (g / day) per bag is 55 or less.

4. The method for curing vanilla beans according to Claim 1 or 2, wherein the cell disruption treatment of the green vanilla beans is not performed.

5. The method for curing vanilla beans according to Claim 1 or 2, further comprising a step of drying at 10°C to 50°C after sealing the bag.

6. The method for curing vanilla beans according to Claim 1 or 2, wherein the sterilization treatment is performed under conditions that do not inactivate β-glucosidase present in the green vanilla beans.

7. A method for manufacturing cured vanilla beans having the method for curing vanilla beans according to Claim 1 or 2.