Carrot juice and method for producing the same

Abstract

To provide a method for producing carrot juice that enables reduction of loss of carrot raw material and enhancement of juicing efficiency.SOLUTION: A method for producing carrot juice, comprising a step of blanching a carrot so that the core temperature becomes 60°C or more and less than 75°C and the hardness becomes 10-35 kgf, a step of grinding the blanched carrot to a median diameter of 200-950 μm by combining at least one crushing treatment and at least one grinding treatment, and a step of juicing the carrot that has been subjected to grinding in addition to crushing.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing carrot juice with high squeezing efficiency, suitable as a raw material for vegetable drinks. [Background technology]

[0002] Consumption of vegetable drinks has become widely accepted among consumers as a convenient way to supplement vegetable deficiencies. Carrots are one of the main ingredients in vegetable drinks, due to their high beta-carotene content and sugar content. Carrots are processed into purees, juices, etc., and blended into vegetable drinks, significantly affecting the overall taste of the drink. However, carrots also have unpleasant flavors, such as an earthy smell and a bitter, astringent taste. Therefore, efforts have been made to improve the taste of processed carrot products. For example, Patent Document 1 reduces the unpleasant flavors by crushing raw carrots and blanching them before juicing. Patent Document 2 also balances the flavor of processed carrot products by cutting off the stems and tips of the carrots and then blanching them. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 10-313835 [Patent Document 2] Japanese Patent Application Publication No. 2019-76003 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0004] Blanching not only affects the taste of processed carrots, but is also a necessary process for inactivating various enzymes contained in carrots and removing nitric acid. However, in mass production at factories, problems have arisen such as the carrots falling apart after blanching, the loss of various soluble solids from the raw carrots into the blanching water, and a decrease in juice extraction efficiency.

[0005] The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for reducing loss of carrot raw materials and improving juicing efficiency when producing carrot juice to be used as a raw material for vegetable juice and the like. [Means for solving the problem]

[0006] The present inventors conducted extensive research to solve the above problems and discovered that the deterioration in juicing efficiency was caused by the blanching temperature being set too high, resulting in softening of the carrots. They then discovered that the above problems could be solved by adjusting the core temperature and hardness of the carrots before crushing to within specific ranges, and then adjusting the carrots to a specific particle size by combining crushing and grinding, thereby achieving the present invention. Specifically, the present invention is as follows:

[0007] [1] Blanching carrots so that the core temperature is 60 ° C or more and less than 75 ° C and the hardness is 10 to 35 kgf; A step of grinding the blanched carrot to a median diameter of 200 to 950 μm by combining at least one crushing treatment and at least one grinding treatment; A step of squeezing juice from the crushed and ground carrots; A method for producing carrot juice, comprising: [2] The method for producing carrot juice according to [1], further comprising a step of cutting the carrots to a thickness of 10 to 45 mm before the blanching. [3] The method for producing carrot juice according to [1], wherein the carrots to be blanched are peeled by exposing them to steam or hot water of 80°C or higher, and then washed with water of 30°C or lower. [4] A method for producing a vegetable-containing beverage, characterized in that carrot juice produced by the method according to any one of [1] to [3] is blended as a beverage ingredient. [5] Blanching the carrots so that the core temperature is 60 ° C or more and less than 75 ° C and the hardness is 10 to 35 kgf; A step of grinding the blanched carrot to a median diameter of 200 to 950 μm by combining at least one crushing treatment and at least one grinding treatment; A step of squeezing juice from the crushed and ground carrots; A method for improving the production yield of carrot juice, comprising: [6] Blanching the carrots so that the core temperature is 60 ° C or more and less than 75 ° C and the hardness is 10 to 35 kgf; A step of grinding the blanched carrot to a median diameter of 200 to 950 μm by combining at least one crushing treatment and at least one grinding treatment; A step of squeezing juice from the crushed and ground carrots; A method for increasing the GABA and β-carotene contents in carrot juice, comprising: [Effects of the Invention]

[0008] The method for producing carrot juice of the present invention can reduce loss of raw carrot material and improve juicing efficiency. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of the present invention will be described below. The method for producing carrot juice according to this embodiment is characterized by comprising: a step of blanching carrots to a core temperature of 60°C or higher but lower than 75°C and a hardness of 10 to 35 kgf; a step of grinding the blanched carrots to a median diameter of 200 to 950 μm by combining at least one crushing treatment and at least one grinding treatment; and a step of squeezing the carrots that have been crushed and ground. The method for producing carrot juice according to this embodiment will be described in more detail below, but the production method of the present invention is not limited to the method described below.

[0010] Here, a method for producing carrot juice will be described, which includes the steps of washing and peeling raw carrots (washing and peeling step), rinsing the carrots in water at 30°C or below (cold water washing step), cutting the carrots (pre-blanching step), blanching the carrots (blanching step), crushing the blanched carrots to produce crushed carrots (crushing step), grinding the crushed carrots to obtain crushed carrots (grinding step), and squeezing the crushed carrots to obtain carrot juice (juicing step). Note that a water-adding step may be included simultaneously with or between the crushing and grinding steps, if necessary.

[0011] (Carrot) In the present invention, carrot refers to a plant of the Apiaceae family, a vegetable whose roots are primarily edible. Examples of carrot varieties include fruit varieties such as Koyo No. 2, Aiko, Saiho, and Beta-312, and varieties used as ingredients for vegetable beverages such as Kuroda Gosun and Shui.

[0012] (Cleaning and peeling process) The washing and peeling process is a process in which raw carrots are washed and peeled. The carrots used are preferably those in which the upper leaves have been cut off together with the stalk. For example, a brush-type washing machine with a brush can be used to wash away dirt and other debris from the carrot surface, as well as drum-type and shower-type washing machines. Preferably, a steam peeler or hot water shower is used to expose the carrots to steam or hot water at 80°C or higher, preferably 85°C or higher, and more preferably 90°C or higher, to lightly steam the surface and soften the outer skin, after which the thin skin is removed. The peeled carrots are preferably subjected to enzyme inactivation treatment by blanching within one day or more, particularly within 12 hours or less, after peeling. Leaving the carrots in a peeled state for one day or more affects the properties of the carrot juice, making it difficult to prevent aggregation.

[0013] (Cold water washing process) In an embodiment of the present invention, a cold water washing step is preferably provided. In the cold water washing step, the peeled carrots are washed with water at 30°C or less to remove the remaining peeled skin and fine roots. If the carrots are peeled after being exposed to steam or hot water, the carrots are cooled after the washing and peeling step, which also has the effect of reducing the heat history of the carrots.

[0014] (Blanching pre-treatment process) The blanching pretreatment step is a step of cutting carrots so that the carrots will have an appropriate core temperature and hardness after blanching. Preferably, the carrots are cut lengthwise from the stem to the tip, passing through the core, and then cut lengthwise so that the core is exposed on the cut surface. The carrots are cut to a thickness of, for example, 10 to 45 mm, preferably 10 to 25 mm, and more preferably 10 to 20 mm. The thickness of the carrots is appropriately adjusted by the blanching temperature in the blanching step described below so that the target core temperature and hardness are obtained.

[0015] (Blanching process) The blanching step in this embodiment is a step of adjusting the core temperature of cut carrots to 60°C or higher and lower than 75°C, and the hardness to 10 to 35 kgf. Core temperature refers to the temperature at the center of the carrot, and is adjusted to be equal to or higher than 60°C but lower than 75°C, preferably equal to or higher than 65°C but lower than 75°C, and more preferably between 65°C and 70°C. A core temperature of 60°C or higher makes it possible to inactivate enzymes such as pectinesterase and pectinase in the carrot, making it easier to prevent aggregation in the carrot juice. On the other hand, a core temperature of less than 75°C makes it easier to achieve the hardness described below and prevents useful components such as nutrients in the carrot from leaking out. The core temperature of the carrot can be measured by inserting a thermometer into the center of the carrot after the blanching process. The hardness of the carrots is adjusted to 10 to 35 kgf, preferably 10 to 30 kgf, and more preferably 15 to 25 kgf. The compressive strength of the blanched carrots is measured using a force gauge, and the first peak is taken as the hardness of the carrots.

[0016] The processing temperature in the blanching step is, for example, 60 to 100° C., preferably 60 to 80° C., more preferably 65 to 80° C., and even more preferably 65 to 75° C. The processing temperature in the blanching step is adjusted as appropriate so as to obtain carrots with the core temperature and hardness described above.

[0017] The processing time for the blanching step is 10 to 30 minutes, preferably 10 to 25 minutes, more preferably 15 to 25 minutes, and even more preferably 15 to 20 minutes. It is important that the core temperature during blanching is 60°C or higher but lower than 75°C and the hardness is 10 to 35 kgf, but the processing time is not important.

[0018] The specific method of blanching is not particularly limited, but possible methods include placing carrots in a mesh and submerging them in a hot water bath, or passing the carrots through a hot water bath on a conveyor, whereby the carrots pass through hot water at a predetermined temperature.

[0019] (Crushing process) The crushing process is a process (crushing process) in which blanched carrots are crushed to produce crushed carrots. The crushing process in this embodiment is a process in which carrots are crushed using shear force to a degree that facilitates the subsequent crushing process while maintaining maximum hardness. It is considered that carrots are crushed until their size is equal to or smaller than the maximum raw material size specified for the equipment used in the crushing process (for example, a median diameter of approximately 1500 to 10,000 μm). The specific size of carrots obtained through the crushing process may be a median diameter of 8,000 μm or less, or even 5,000 μm or less. Since crushing is performed after crushing in this embodiment, the lower limit is not particularly limited, and may be, for example, a median diameter of 1,600 μm or more, or 2,000 μm or more. While this size is preferable, it is not necessarily within this range. By undergoing the crushing process, the processing time in the crushing process can be shortened and the carrots can be crushed more finely in the crushing process, which tends to prevent clogging of the equipment and further improve processing efficiency. The crushing process is carried out using a single-axis, double-axis, hammer, pusher, or screw type crusher, and more specifically, using a device that crushes carrots by applying impact, such as a hammer mill or hammer crusher.

[0020] (grinding process) The grinding step is a step in which ground carrots are ground by grinding to obtain ground carrots. The grinding method includes so-called mashing, in which the carrots are ground by applying compressive force and shear force to scrape off the surface of the particles. As a guideline, it is preferable that the specific size of the carrots obtained through this grinding step is ground to a size suitable for the subsequent juicing step, and it is preferable that the carrots after the grinding step are ground to a puree-like state. The grinding step is carried out using a millstone type, rotary type, or screw type grinder, and specifically using a device that grinds carrots by applying pressure to them, such as a mass colloider, shear pump, colloid mill, or disc mill.

[0021] (Crushing and grinding process) The crushing step and the grinding step may be carried out separately or consecutively. An embodiment of the present invention is characterized by combining at least one crushing treatment with at least one grinding treatment. Combining these two types of treatments breaks down carrot cells more finely, leading to an improvement in the yield in the subsequent juicing step. The particle size (median diameter) of the ground carrot product obtained by combining at least one crushing treatment with at least one grinding treatment is preferably 200 to 950 μm, more preferably 200 to 700 μm, and even more preferably 350 to 700 μm. The particle size of the ground carrot product can be measured using the pomace after the juicing step described below.

[0022] (added water) Water can be added as needed in the crushing and grinding processes. Adding water reduces the viscosity of the crushed and ground carrots, allowing for smoother machine movement during the crushing and grinding processes, and also facilitates solid-liquid separation in the subsequent juicing process, which is expected to improve yield. The method of adding water is not particularly limited, and examples include adding water to the carrots separated from hot water after blanching, or adding water to the machine performing the crushing or grinding process. The amount of water added is preferably 0.5 to 4 times, more preferably 1 to 3 times, and even more preferably 1.5 to 2.5 times the weight of the carrots added as raw materials. Adding a large amount of water results in a highly viscous puree, while adding less water results in a solid with low fluidity.

[0023] (juice extraction process) The juicing process is a process in which the ground carrots are squeezed to obtain carrot juice. The juicing method may be a centrifugal juicer such as a double can decanter, a compression juicer such as a two-axis rotary extruder or a juicer, or a method in which the ground carrots are squeezed by flannel filtration and then centrifuged (3000 rpm, 10 minutes) to obtain carrot juice, or other methods may be used.

[0024] (mixing and sterilization) The obtained carrot juice is adjusted for taste, odor, concentration, pH, etc. as needed, and is also sterilized. Blending can be carried out in the same manner as for ordinary carrot juice. The pH can be adjusted, for example, to an acidic range, preferably around pH 4.2, using a citric acid solution. When producing vegetable juice, juices squeezed from other vegetables or fruits can be mixed in this step. Sterilization can be carried out using ordinary sterilization treatments depending on the container to be filled.

[0025] (concentration process) The squeezed juice obtained in the squeezing step may be concentrated to a desired concentration in a concentration step. The concentration method is not particularly limited, but an example is a method in which water is evaporated under reduced pressure. At this time, the squeezed juice may be heated to promote evaporation. The heating temperature in the concentration step is preferably 40 to 100°C.

[0026] (sterilization process / filling process) The production method of this embodiment may further include a sterilization step of sterilizing the squeezed juice and a filling step of filling the squeezed juice into a container. The order of the sterilization step and the filling step is not particularly limited, and the sterilization step may be performed on the squeezed juice before filling, or may be performed after filling into a container.

[0027] The container into which the squeezed juice is filled is not particularly limited, and examples thereof include metal cans (steel cans, aluminum cans, etc.), PET containers, paper containers, glass bottles, etc. The squeezed juice may be a concentrated product packed in a container (concentrate), or may be an RTD (Ready To Drink) that can be consumed as is after purchase.

[0028] The conditions for the sterilization treatment are not particularly limited, but for example, when the product is to be supplied as a beverage ingredient, it may be treated at 120 to 140°C for 10 to 30 seconds.

[0029] (Storage process) The production method of this embodiment may further include a storage step of storing the squeezed juice filled in the container at −40 to 0° C. The squeezed juice that has undergone the sterilization step can be stored at low temperatures with stable quality.

[0030] (carrot juice) The carrot juice obtained as described above may be concentrated as it is or added with water to produce a beverage, or may be used as a raw material for other packaged beverages.

[0031] (Yield improvement method) The method for improving the production yield of carrot juice of this embodiment is characterized by comprising: a step of blanching carrots to a core temperature of 60°C or higher but lower than 75°C and a hardness of 10 to 35 kgf; a step of grinding the blanched carrots to a median diameter of 200 to 950 μm by combining at least one crushing treatment and at least one grinding treatment; and a step of squeezing the carrots that have been crushed and ground. Each step of the method for improving the production yield can be the same as in the production method described above.

[0032] (Method for increasing GABA and beta-carotene content) The method for increasing the GABA and β-carotene contents in carrot juice of this embodiment comprises the steps of: blanching carrots to a core temperature of 60°C or higher but lower than 75°C and a hardness of 10 to 35 kgf; grinding the blanched carrots to a median diameter of 200 to 950 μm by combining at least one crushing treatment and at least one grinding treatment; and squeezing the crushed and ground carrots. Each step of the method for increasing the contents can be the same as in the production method described above. By adjusting the core temperature and hardness in the blanching process as described above, the odor of the carrot juice can be reduced, the flavor can be improved, and the GABA (γ-aminobutyric acid) content can be increased compared to conventional manufacturing methods. Furthermore, by adjusting the hardness and median diameter as described above, the β-carotene content in the carrot juice can be increased compared to conventional manufacturing methods.

[0033] <Terminology> In this specification, when "X to Y" (X and Y are any numbers) is expressed, it includes the meaning of "X or more and Y or less" as well as "preferably greater than X" and "preferably smaller than Y" unless otherwise specified. Furthermore, when "X or more" or "Y or less" (X and Y are any numbers), it includes the meaning of "preferably greater than X" or "preferably smaller than Y" unless otherwise specified.

[0034] The above-described embodiments have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention. [Example]

[0035] The present invention will be explained in more detail below by showing production examples, test examples, etc., but the present invention is not limited to the following production examples, test examples, etc.

[0036] (Method for producing carrot juice) Example 1 Approximately 500 g of raw carrots (variety: Shugi) with the stems removed were exposed to a hot water shower at approximately 90°C for approximately 1 minute, peeled with a metal scrubber (washing and peeling process), and cooled with tap water at 25°C (cooling process). The carrots were then cut into 2 cm thick slices, passing through the top and core (pre-blanching process). These were then blanched in ion-exchanged water at 75°C (blanching water) for 15 minutes. The blanched carrots were crushed to approximately 1500 μm using an electric carrot crusher (Shiboru-kun), and then 50% of the carrot weight was added and the carrots were ground in a blender. The resulting crushed carrots were weighed and subjected to solid-liquid separation in a juicer. The weight and Brix of the resulting carrot juice and the median diameter of the resulting juice residue were measured. The resulting carrot juice was also subjected to an agglomeration test according to the criteria described below to confirm its properties. Furthermore, the carrot juice was subjected to a sensory evaluation according to the criteria described below. The results are shown in Table 1.

[0037] Examples 2 to 6 and Comparative Examples 1 to 8 Examples 2 to 6 and Comparative Examples 1 to 8 were produced in the same manner as in Example 1, except that the steps and conditions of Example 1 were changed to the steps and conditions described in Table 1 for each Example and Comparative Example.

[0038] (How to measure carrot core temperature) The core temperature was measured by piercing the center of the carrots immediately after blanching using a Yokogawa Measurement Corporation TX10 series digital thermometer.

[0039] (Method for measuring carrot hardness) The blanched carrots were immediately immersed in ice water to fix their hardness immediately after blanching. Compressive strength was measured using an IMADA force gauge ZTA-1000N, and the first peak was taken as the hardness of the carrots.

[0040] (Method for measuring particle size of ground carrots) The median diameter was measured on a volume basis for the juice residue using a laser diffraction particle size distribution analyzer SALD-2300 manufactured by Shimadzu Corporation.

[0041] (GABA measurement method) Each carrot juice was filtered to prepare a sample for HPLC. The prepared HPLC sample was subjected to an automated pre-column derivatization method using HPLC to detect and measure GABA (γ-aminobutyric acid). Column: CAPCELLPAK C18 TYPE AQ (3.0 mm id x 150 mm) (Osaka Soda Co., Ltd.) Equipment: Waters HPLC

[0042] (Method for measuring beta-carotene) Each carrot juice was weighed into a 50 ml brown volumetric flask, and distilled water was added to bring the total volume to 2.5 ml. 20 ml of a HAET mixture (hexane:acetone:ethanol:toluene = 10:7:6:7 (volume ratio)) was added, followed by the addition of ethanol to bring the total volume to 50 ml. The resulting mixture was subjected to ultrasonic treatment for 10 minutes, filtered through an organic solvent filter, and subjected to HPLC analysis under the following conditions.

[0043] =HPLC conditions= Column: YMC J2sphere ODS-H80 S-4μm 8nm φ3.0mm×75mm Guard column: YMC guard column ODS-H80 S-4μm 8nm φ2.0mm / 10mm Column temperature: 40℃ Detection wavelength: UV 455 nm Flow rate: 0.9ml / min Injection volume: 10μL Mobile phase: methanol Sample temperature: 10℃

[0044] (Method for measuring juice yield and juice extraction efficiency) Blanched, crushed, and ground carrots were juiced using a juicer (Kuvings) manufactured by NUC JAPAN Co., Ltd. Juice yield (%) was calculated from the input amount and the weight of the juice, and juice efficiency (%) was calculated taking into account the sugar content (Bx) of the juice and the sugar content (Bx) of the raw material. Squeezed liquid yield (%) = Squeezed liquid weight (g) / Total amount of ground material (g) × 100 Squeezing efficiency (%) = weight of squeezed liquid (g) / concentrated sugar content (Bx) x sugar content of squeezed liquid (Bx) / weight of ground material (g) x 100

[0045] (Properties) Ten mL of juice was collected from Examples 1 to 6 and Comparative Examples 1 to 8, and adjusted to pH 4.2 using a 5% citric acid solution dissolved in pure water at room temperature. 10 mL of the juice was then poured into a 15 mL test tube and heated in hot water at 80° C. for 7 minutes. It was then allowed to stand at room temperature for 5 minutes, and its properties were evaluated.

[0046] (flavor) Five expert panelists evaluated the flavor by taking 10 mL of juice prepared with pure water in Bx6 and adjusted to 20°C. They also took a negative control under the same conditions to share a common understanding of odor and flavor intensity. The evaluation was based on the following criteria: ◎: "No odor, tastier than the negative control (conventional method), and stronger flavor," ○: "Same as the negative control (conventional method)," △: "Slightly more odorous and weaker flavor than the negative control (conventional method)," and ×: "More odorous and weaker flavor than the negative control (conventional method)," with the most common evaluation being used.

[0047] = Juicing efficiency = ◎: 130% or more of the negative control (conventional method) ○: 120% or more but less than 130% of the negative control (conventional method) △: Same as negative control (conventional method) (90% or more but less than 120%) ×: Less than 90% of the negative control (conventional method)

[0048] =Properties= ◎: Solids are uniformly dispersed 〇: Almost uniform △: Some separation is observed ×: Solids and liquid are completely separated

[0049] =flavor= ◎: No odor and tastes better than the negative control (conventional method), with a strong flavor ○: Same level as negative control (conventional manufacturing method) △: Slightly stronger odor and weaker taste than the negative control (conventional method) ×: Smellier and weaker in taste than the negative control (conventional method)

[0050] =Overall rating= ◎: No × or △ in the evaluation of juice extraction efficiency, properties, or flavor, and there are more ◎ than 〇 〇: No × or △ in the evaluation of juice extraction efficiency, properties, or flavor, and there are more 〇 than ◎ △: No × ratings in the evaluation of juice extraction efficiency, properties, or flavor, but some △ ratings ×: There is an × in the evaluation of juice extraction efficiency, properties, or flavor.

[0051] [Table 1]

[0052] In Comparative Example 4, crushing and grinding were not performed, and as a result, juicing was not possible. As shown in Table 1, by using the method of the present invention, it was possible to produce carrot juice that reduces loss of raw carrot material and improves juicing efficiency. Furthermore, the carrot juice obtained by the method of the present invention had a reduced odor and a good flavor, and the GABA and β-carotene contents were higher than those of conventional production methods.

Claims

1. Blanching the carrots so that the core temperature is 60 ° C or higher and lower than 75 ° C and the hardness is 10 to 35 kgf; Grinding the blanched carrot to a median diameter of 200 to 950 μm by combining at least one crushing treatment and at least one grinding treatment; A step of squeezing juice from the crushed and ground carrots; A method for producing carrot juice, comprising:

2. The method for producing carrot juice according to claim 1, further comprising a step of cutting the carrots to a thickness of 10 to 45 mm before the blanching.

3. 2. The method for producing carrot juice according to claim 1, wherein the carrots to be blanched are peeled by exposing them to steam or hot water of 80°C or higher and then washed with water of 30°C or lower.

4. A method for producing a vegetable-containing beverage, comprising blending carrot juice produced by the method according to any one of claims 1 to 3 as a beverage ingredient.

5. Blanching the carrots so that the core temperature is 60 ° C or higher and lower than 75 ° C and the hardness is 10 to 35 kgf; Grinding the blanched carrot to a median diameter of 200 to 950 μm by combining at least one crushing treatment and at least one grinding treatment; A step of squeezing juice from the crushed and ground carrots; A method for improving the production yield of carrot juice, comprising:

6. Blanching the carrots so that the core temperature is 60 ° C or higher and lower than 75 ° C and the hardness is 10 to 35 kgf; Grinding the blanched carrot to a median diameter of 200 to 950 μm by combining at least one crushing treatment and at least one grinding treatment; A step of squeezing juice from the crushed and ground carrots; A method for increasing the GABA and beta-carotene contents in carrot juice, comprising:

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