JPH1142100A - Production of granulated sugar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing easily handleable granulated sugar containing tasty, flavoring and nutrient components at a reduced cost. SOLUTION: This process for the production of granulated sugar includes (1) a step to prepare a sugar syrup, (2) a concentration step, (3) a crystallization step and (4) a drying and finishing step. The pure sugar content of the sugar syrup produced by the step 1 is adjusted to 87.0-95.1 wt.% before entering into the step 2, the step 3 comprises the solidification of the syrup under a high shearing force to obtain granulated sugar, and the step 4 comprises the drying of the granulated sugar delivered from the step 3 by introducing the sugar into a hopper supplied with dry air through the bottom of the hopper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing granular sugar, and more particularly, to a method for producing granular sugar in which a drying and finishing step is simplified.

[0002]

[0003] In recent years, with the increase in health foods, consumers who recognize that purified sugars (such as white sugar and granulated sugar), which are almost pure sucrose, are nutritionally unbalanced. It is increasing and its consumption is decreasing year by year. On the other hand, there is a tendency to favor brown sugar or trisaccharide having no flavor or nutritional components, or sugars having enhanced nutritional components or minerals. Therefore, various sugars such as glucose and fructose, which are nutritionally valuable, rich mineral components such as calcium, potassium, and magnesium, and vitamins that are effective for maintaining health are included in the raw sugar solution (for example, cane juice). There is a need for a sugar product containing trace components.

[0003] Furthermore, in general households, it is easy to handle,
In many cases, a sugar product that is easy to dissolve is desired, and even for those who manufacture and sell food, the liquidity is good,
Granular sugars that are difficult to caking are preferred. Consolidation refers to the solidification of sugar and loss of fluidity, which is a major factor in reducing the commercial value of sugar products. Therefore, being hard to consolidate is a very preferable feature.

[0004] There is still a problem that low-cost production of granular sugar having a function as a health food leaving such flavors and nutrients remains.

[0005] The process of producing sugar mainly comprises a process of preparing a sugar syrup, a concentration process, a crystallization process, and a drying and finishing process. In particular, a crystallization process solidified by conventional sugar decoction, granulation, granulation and the like. If the subsequent drying and finishing process is not sufficiently performed, a problem of caking occurs during storage of the product, and the product value is lost.

[0006] Generally, the drying and finishing step includes firstly a drying step using a dryer, secondly a cooling step using a cooler, and a third step.
And a ripening step using a hopper. Specifically, the drying step is a step of drying with a dryer in order to reduce the moisture of the sugar product and prevent caking. For example, in the case of granulated sugar, the water content when discharged from the centrifugal separator is 0.6 to 1.5% by weight.
After drying with a dryer at 0 to 75 ° C., drying is carried out until the water content becomes about 0.02% by weight. Here, if the sugar product is directly introduced into the hopper without drying with a drier, there is a high possibility that caking occurs due to variation in the amount of water.

[0007] Next, the cooling step is a step of cooling the sugar product dried by a dryer with a cooler and lowering the temperature to about 35 to 45 ° C. Here, if the sugar product dried by the dryer is directly put into the hopper without a cooling step, there is a high possibility that the product is solidified by the retained heat and / or by a part of the remaining moisture.

The aging step is a step of homogenizing the cooled sugar product with a hopper in order to further stabilize in terms of moisture and prevent caking. The sugar product, usually cooled by a cooler, is aged in a hopper in which dry air is blown, to remove moisture that is taken into the sugar and causes caking. After this aging, it is packed and shipped as a product.

As a dryer used in the drying step,
Fluid bed dryers, flash dryers, rotary dryers and the like are well known. Further, as a sugar cooler used in the cooling process, a rotary drum cooler, a vacuum belt cooler and the like are known. However, equipment costs are required for any machine, and when a new manufacturing facility is installed, it may lead to an increase in product cost.

[0010] As described above, in the drying and finishing step, there are many machines to be installed, such as a dryer, a cooler, and a hopper, and enormous equipment costs for drying and cooling are required. There have been some attempts to improve the drying method. For example, after drying with a fluidized bed dryer, aging with a hopper (Japanese
No. 480); Drying with a drum dryer
55-9200); a method of drying with a rotary dryer (Japanese Patent Application Laid-Open No. 60-256399); and a method of drying using a crystallizer continuously for a long time (Japanese Patent Application Laid-Open No. 57-138400). In any of these methods, since a drying machine is used or a crystallizer is operated for a long time to dry, the industrial production efficiency is not good, and the physical properties of the produced granular sugar are not good (particle size distribution). Wide, poor fluidity, easy to consolidate, etc.). As described above, there has been no report on improving the manufacturing method by focusing on simplification of the drying and finishing step while maintaining the quality of the product, and a lower-cost drying and finishing step has been desired.

[0011] It is an object of the present invention to provide a method for producing granulated sugar containing flavor and nutritional components and which is easy to handle at a lower cost.

[0012]

Means for Solving the Problems In the method for producing granular sugar, the present inventors adjusted the pure sugar ratio of the sugar syrup entering the concentration step to 87.0 to 95.1% by weight, and adjusted the sugar after concentration. When the syrup is solidified by applying a strong shearing force to obtain granulated sugar, it is dried and finished only in the process using a hopper (corresponding to the conventional aging process) without using a dryer and a cooler which requires expensive equipment. That the process can be simplified,
The granulated sugar thus obtained has a function as a health food in which flavors and nutrients remain as it is, has excellent fluidity, and is hardly solidified, and has completed the present invention.

That is, the present invention provides a method for producing granular sugar including a step of preparing a sugar syrup, a concentration step, a crystallization step, and a drying and finishing step, and enters a concentration step obtained through a step of preparing a sugar syrup. Adjusting the pure sugar ratio of the previous sugar syrup to 87.0 to 95.1% by weight, the crystallization step being a step of solidifying while applying a strong shearing force to obtain granular sugar; And a drying and finishing step, wherein the granular sugar obtained from the crystallization step is a step of drying by sending it into a hopper to which dry air is sent from the bottom.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing granular sugar of the present invention is an improvement on a conventionally known method for producing granular sugar, which comprises a step of preparing a sugar syrup, a concentration step, a crystallization step, and a dry finishing step.
The process is shortened. In the method of the present invention, by setting the pure sugar ratio of the sugar syrup to a specific range, and by performing crystallization while applying a strong shearing force, the step of using a dryer and a cooler is omitted, and only a hopper is used. A dry finish can be performed. The step of preparing the sugar syrup and the step of concentrating are carried out by a conventional step operation in the art. In the method of the present invention, the purity of the sugar syrup from the step of preparing the sugar syrup to the concentration step is reduced to 87.0-9.
It is necessary to adjust to 5.1% by weight, preferably 90.0 to 95.1% by weight. Since the sucrose is decomposed in a later step, the pure sugar ratio of the product (granular sugar) is adjusted to 86.0 to 93.1% by weight, preferably 89.0%, by adjusting the pure sugar ratio in this way. ９３93.1% by weight. If the pure sugar percentage is too high, the flavor and nutrient components will be lacking. Further, in the drying and finishing step, if the solidified granular sugar is put into the hopper with high moisture and temperature, the risk of solidification in the hopper is high due to the high purity sugar ratio. Cannot produce granulated sugar that can be directly dried. Further, if the pure sugar rate is too low, the production rate of continuous production in a crystallization step, for example, a horizontal continuous crystallizer with a high-speed rotating paddle, decreases,
The adhesion of solids inside the machine becomes significant. Also in the next drying finishing step, the amount of air blown by the drying air is increased, and the drying time is increased. Then, it is necessary to enlarge the hopper or increase the number of hoppers, and as a result, the cost is increased.

The percentage of pure sugar is calculated from the sugar content measured by the Spencer method described in "Sugar Manufacturing Handbook" (edited by the Society for the Study of Sugar Refining Technology, published on June 30, 1962, Asakura Shoten).

[0016]

## EQU1 ## The value of pure sugar content = (sugar content / solid content) × 100 (1) (the unit of solid content is% (weight / weight)).

As the sugar syrup, more specifically,
A sugar syrup prepared by adding sucrose and / or a sucrose solution to cane juice so as to have a pure sugar ratio of 87.0 to 95.1% by weight is used. Dependent. In order to achieve the above pure sugar ratio, the ratio of the solid content of cane soup to the weight of granulated sugar [that is, (the weight of solid content of cane juice) / (the weight of granulated sugar) × 100] is usually 30 to 70% by weight.
So that

In the present invention, the term "sugar cane juice" means a pressed juice obtained by pressing sugar cane (sugar cane) or a leached juice obtained by leaching sugar cane.

The type of sucrose and / or sucrose solution is
The shape and the like are not particularly limited, and one or more kinds of raw material sugar, granulated sugar, white sugar (above, crystalline sugar), fine liquor (liquid sugar) and the like can be used.

In the process of preparing a sugar syrup, the sugar syrup having a pure sugar percentage as described above undergoes, for example, a process of adding cane juice to a lime milk and heating it, and then adding sucrose and / or a sucrose solution to the syrup. Or a method obtained by filtering sugar cane juice, adjusting the pH to 5.0 to 6.0, and adding sucrose and / or a sucrose solution thereto. The latter method (without lime cleaning) is more preferable because the quality of the finally obtained granulated sugar is good (coloring is suppressed and flavor and nutrient components remain) and it is versatile. The step of preparing a sugar syrup is preferably performed as follows. That is, first, lime cleaning is not performed, and sugar cane juice is filtered to remove foreign substances. Examples of the filtration method include screen filtration, diatomaceous earth filtration, microfiltration, and ultrafiltration which are widely used in the food industry. Among them, ultrafiltration is preferable, and the molecular weight cut off is 150,000 or less, more preferably 30,000 to 150,000.
It is particularly preferred to carry out ultrafiltration. Ultrafiltration methods include, for example, tube type ultrafiltration, plate type ultrafiltration,
Spiral ultrafiltration, hollow fiber ultrafiltration and the like can be preferably used.

When a sugar syrup having a high pure sugar ratio is obtained, solidification can be performed later without performing filtration. However, when a sugar syrup having a specific pure sugar ratio as described above is used, for example, In the subsequent crystallization step using a horizontal continuous crystallizer equipped with a high-speed rotating paddle, it is preferable to carry out the above ultrafiltration in order to achieve efficient and stable production. Such inconvenience in the case of not performing filtration is presumed to be due to the presence of high molecular weight impurities derived from sugarcane or suspended substances (eg, polysaccharides, pigments, etc.).

The pH of the filtered sugar cane juice ranges from 4.8 to 5.8 depending on the variety of the raw sugar cane.
In order to prevent the decomposition of sugar in the subsequent concentration step, the pH is preferably adjusted to 5.0 to 6.0. If the pH is too low, the decomposition of sucrose during heating becomes remarkable, and it tends to be difficult to purify the solid sugar.If the pH is too high, the flavor changes during subsequent concentration and the It tends to change to such a flavor and coloring tends to progress.

As described above, the sugar content of the sugar cane juice whose pH has been adjusted is determined using sucrose and / or a sucrose solution as described above.
It is adjusted to 7.0 to 95.1% by weight. The sugar syrup thus obtained proceeds to the next concentration step.

The concentration step is preferably performed as follows. That is, by successively concentrating the sugar syrup using a three-stage plate heat exchanger (two-stage vacuum concentration and one-stage normal pressure concentration), it is possible to efficiently concentrate the sugar syrup while suppressing decomposition and coloring of sucrose. In the method using a three-stage plate heat exchanger, the steam generated in the first stage can be reused in the second stage. Therefore, the plate-type concentrator having only one stage or the reduced-pressure concentration in only one stage. Steam energy can be used more effectively than concentrating the sugar syrup using a machine. In order to perform concentration in a three-stage plate heat exchanger, for example, the sugar syrup (pure sugar ratio: 87.0 to 95.1% by weight) from the preceding step is firstly passed through the first plate heat exchanger. Heat and concentrate the Brix degree (Bx) from about Bx28 to about Bx40. Under reduced pressure, the concentrated liquid is separated from the vapor by a vapor separator, and the concentrated liquid is sent to the next second plate heat exchanger, where it is heated and concentrated from about Bx40 to about Bx65. On the other hand, the steam separated by the first vapor separator is supplied to the steam site of the second plate heat exchanger. Further, the concentrated solution obtained in the second step is separated from steam under a reduced pressure by a vapor separator, and the concentrated solution is concentrated by heating from about Bx65 to about Bx93 in the last plate heat exchanger. The obtained concentrated liquid is separated from steam by a vapor separator under normal pressure. The sugar syrup concentrated to about Bx93 is sent to the crystallization step to be solidified. In the subsequent crystallization step, particularly when a horizontal continuous crystallizer with a high-speed rotating paddle is used, in order to perform solidification well, in the concentration step, Bx is concentrated to about 90.5 to 95.3. preferable. If the concentration has not progressed, ie B
If x is low, it may be difficult to solidify using a horizontal continuous crystallizer with a high-speed rotating paddle. If the concentration is too high, that is, if Bx is high, the horizontal continuous crystallizing machine with a high-speed rotating paddle may be used. Before entering, the flow slows down,
Solidification may occur, causing problems such as clogging of the piping.

In the subsequent crystallization step, when a horizontal continuous crystallizer with a high-speed rotary paddle is used, the condition of solidification is greatly affected. Therefore, Bx after the concentration by the last plate heat exchanger is set in the above range. About the conditions for
It is preferable to consider in advance. That is, since the relationship between the liquid temperature of the sugar solution under normal pressure and Bx is well known, based on this conversion table, the final outlet temperature of the concentration of the plate heat exchanger (the temperature of the inlet of the vapor separator). Thus, Bx before entering the horizontal continuous crystallizing machine with a high-speed rotating paddle can be obtained. For example, when Bx is set to 93 and it is desired to feed the product to a horizontal continuous crystallizer equipped with a high-speed rotary paddle, the concentration temperature of the plate heat exchanger may be set to about 127 ° C. from the conversion table. Thus, by monitoring the outlet temperature of the concentration of the last plate heat exchanger, that is, the temperature of the inlet of the vapor separator, the concentration step can be performed efficiently without directly measuring Bx after the concentration. . In addition, by using the above-described processing method for adjusting the pH of sugarcane juice and concentrating sugar syrup,
Decomposition and coloration of the sucrose in the heat-concentrated sugar syrup can be minimized, and it can be concentrated in a short time to Bx suitable for the crystallization step.

The sugar syrup after concentration is then advanced to a crystallization step. In the present invention, in the crystallization step, it is necessary to perform solidification while applying a strong shearing force. Means for solidifying while applying a strong shearing force include, for example, a universal mixing stirrer, a Nauta mixer, an extruder,
Examples include a kneader, a colloid mill, and a horizontal continuous crystallizer with a high-speed rotating paddle. Of these, a horizontal continuous crystallizer with a high-speed rotating paddle is preferred. The horizontal continuous crystallizing machine with a high-speed rotating paddle is one in which a continuous mixing / dispersing machine is applied as a crystallizing machine, and a typical machine is a turbulizer.

Crystallization by a horizontal continuous crystallizer equipped with a high-speed rotating paddle is preferably performed as follows. Heated dry air is introduced into a horizontal continuous crystallizer with a high-speed rotating paddle. The relative humidity of the heated dry air is RH 10% or less.
The dry air flow rate when operating at the hourly discharge speed is 9
３０30 Nm ³ / minute (when the horizontal continuous crystallizer equipped with a high-speed rotating paddle is operated at a discharge speed of 1 ton / hour of granulated sugar, the air volume of air sent per minute is expressed in Nm ³ units). With the above relative humidity and the above air volume,
The water content of the granulated sugar when coming out of the horizontal continuous crystallizer with a high-speed rotating paddle can be suppressed to 2.5% by weight or less. For this reason, the water content of the granulated sugar output from the horizontal continuous crystallizer equipped with the high-speed rotating paddle can be reduced uniformly and low, so that the next drying and finishing step can be performed favorably. Further, the temperature of the heated dry air is preferably 60 ° C. or more, more preferably 82 to 88 ° C. If the temperature of the heated dry air is too low, the air is cooled by the dry air before sufficient crystallization occurs to cause candy, and the candy is attached inside the horizontal continuous crystallizer with a high-speed rotating paddle. As a result, a load may be applied and the machine may stop. Also, the presence of dry air at too low a temperature causes insufficient evaporation of water due to heat of crystallization. Further, the vapor generated during the solidification is not emitted as a gas to the outside of the crystallizer, but condenses into moisture. for that reason,
Granular sugar comes out in the form of a cream from the outlet of the horizontal continuous crystallizer with a high-speed rotating paddle. On the other hand, if the temperature of the dry air is too high, the drying proceeds too much, causing problems such as candy, decomposition of sucrose and coloring. Also, the flavor is lost. The peripheral speed of a horizontal continuous crystallizer with a high-speed rotating paddle (that is, a paddle linear velocity) is generally 25 to 45 m /
Seconds, preferably 30 to 40 m for uniform particle size distribution
/ Sec. If the peripheral speed is too low, the shearing force will be weak,
It cannot be produced because it does not completely solidify and tends to be creamy and come out of a horizontal continuous crystallizer with a high-speed rotating paddle. If the peripheral speed is too high, the solidified sugar tends to be fine powder rather than granular. In such a fine powder, in the next drying and finishing step, dust is easily formed by blowing dry air in the hopper, resulting in poor operability. Further, there is a problem that dust is generated during use, and the product is solidified at the distribution stage and loses commercial value.

As the concentration and crystallization methods conventionally used for producing granular sugar, for example, a so-called conversion method combining a plate-type evaporator, a colloid mill (or homogenizer) conveyor belt, and a crusher (Japanese Patent Publication No. 55-55) No. -9200), a method using rapid stirring (Japanese Patent Application Laid-Open No. 52-120137), and a method using impact mixing (Japanese Patent Application Laid-Open No. 57-120137).
-138400), a method using a continuous screw extruder (Japanese Patent Application Laid-Open No. 60-256399), and a method combining a vacuum concentrator beater crystallizer and a pulverizer (US Pat. No. 3,194,682). Granular sugar obtained by such a method is not suitable for a subsequent drying and finishing step using only a hopper, and has the following disadvantages. That is, the granular sugar cannot be dried uniformly because of its coarse particle size and wide particle size distribution. The fluidity is poor due to the wide particle size distribution, and it is not suitable for performing a dry finishing step directly in a hopper. It takes a long time to dry because of too much water.
Furthermore, these methods are not suitable for long-term, continuous production on an industrial scale. In Japanese Patent Publication No. 1-16480, a sugar syrup having a pure sugar ratio of 97.1 to 99.9% by weight is produced on an industrial scale using a horizontal continuous crystallizer equipped with a high-speed rotating paddle. However, such granulated sugar having a high pure sugar ratio has a high risk of solidifying in the hopper in the drying and finishing step of the present invention.

The granular sugar obtained through the crystallization step is sent to the next drying and finishing step. A conveyor is usually used to transport the granular sugar solidified in the crystallization step to a hopper in the dry finishing step. The conveyor preferably has means for efficiently removing steam generated from the granulated sugar during transport of the granulated sugar. Such efficient removal of the vapor can be performed by ventilation (air suction or pushing). By adjusting the amount of air, the water content of the granular sugar to be carried can be adjusted. As such a conveyor, for example, a screw conveyor, a vibration conveyor, a continuous flow conveyor, a belt conveyor, or the like can be used. Preferably, the granulated sugar has a water content of 2.0% by weight or less immediately before entering the hopper in the dry finishing step.

Next, the drying and finishing step will be described.
The granular sugar from the crystallization step has a temperature of about 110-120 ° C, but is transported on a conveyor to a hopper,
During this transportation, the vapor generated from the granulated sugar is efficiently removed, and the granulated sugar is cooled down to about 100 ° C. by heat radiation. In the present invention, this granular sugar, from a conveyor,
Without passing through a conventional dryer or cooler, dry air is introduced into the hopper that feeds in from the bottom, and drying, cooling, and aging are performed directly in the hopper. The temperature of the dry air fed into the hopper is preferably about 40-50 ° C.
And the relative humidity at this temperature is preferably R
H 35% or less. The granulated sugar is dried in a hopper until the water content is 1.3% by weight or less, preferably 0.9% by weight or less, and preferably 0.4% by weight or more. In order to make the granular sugar have the above-mentioned water content, the relative humidity of the dry air needs to be RH 35% or less. The moisture content of the granular sugar immediately before entering the hopper from the conveyor is preferably 2.0% by weight or less in order to prevent caking in the hopper.

As the hopper used in the present invention, what is called a sugar bin, a silo, a storage tank, a bottle, or the like is used.

The granular sugar obtained by the method of the present invention has a color value of AI2000 or less, so that it can be used for a wider range of applications than conventional beet sugar-containing products (eg, brown sugar, red sugar). It can have versatility without limiting the range of foods that can be made.

The color value (AI) was determined as follows in accordance with the description in "Sugar Manufacturing Handbook" (edited by the Society for the Study of Sugar Refining Technology, published on June 30, 1962, Asakura Shoten): After dissolving the sample in water to prepare a test liquid of about 25% (weight / weight), the pH was adjusted to 7.0, and the Brix degree (Bx) was measured using a refractometer for measuring Bx. Next, the absorbance (ABS) at 560 nm of the test solution (pH 7.0) was determined using a spectrophotometer. From these measurements, the following equation (2):

[0034]

AI = (1000 × ABS × 100) / (b × Bx × g) (2) (where ABS is the absorbance; b is the optical path length of the cell of the spectrophotometer (cm)) Bx is the degree of Brix (g /
g); g is the specific gravity of the test solution (g / ml)).

The water content of the granular sugar obtained by the method of the present invention is 1.3% by weight or less, preferably 0.9% by weight or less. If the amount of water is too large, it becomes impossible to suppress the coloring and the decrease in flavor over time. However, when the drying is performed under the condition that the water content is too low, the water content is preferably 0.4% by weight or more because natural flavor of sugarcane decreases during a long drying process. The water content is a value measured by a vacuum drying method at 75 ° C. for 3 hours.

The granular sugar obtained by the method of the present invention is a granular sugar having very preferable characteristics. That is, the particle size distribution is narrow and the coefficient of variation is small. further,
A non-crystalline part (so-called honey part) exists in the granulated sugar in a very stable state. Therefore, it has excellent fluidity,
Hard to consolidate. It is easy to handle in terms of use and has good preservability, and also has good workability in manufacturing, especially in the packaging process.

[0037]

According to the method of the present invention, the step of using a drier and a cooler is omitted by setting the pure sugar ratio of the sugar syrup to a specific range and performing crystallization while applying a strong shearing force. Drying can be performed simply by using. For example, Japanese Patent Publication No. 1-16480 discloses a method in which a pressurized thin film concentrator and a horizontal continuous crystallizer with a high-speed rotary paddle are combined, but the sugar syrup used here has a high pure sugar ratio (97. (1 to 99.9%), if it is introduced into the hopper from the screw conveyor after exiting the horizontal continuous crystallizer with the high-speed rotating paddle, there is a high possibility of solidification in the hopper, and it is difficult to perform drying. . Also, such products are likely to solidify during storage.

On the other hand, decoction (granulated sugar, warm sugar, etc.)
The sugar product solidified by the granulation method not based on the method of the present invention is solidified in the hopper by the method of drying directly in the hopper regardless of the purity ratio.

The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

[0040]

[Examples] In the following, the analysis of products is performed according to the method for analyzing raw sugars described in "Sugar Manufacturing Handbook" (edited by the Society for the Study of Sugar Refining Technology, published on June 30, 1962, Asakura Shoten).
The reduced-pressure drying method over time, the pure sugar ratio is determined from the value of the sugar content measured by the Spencer method according to the above formula (1), the reducing sugar is measured by the methylene blue method, the ash is measured by the sulfated ash method, and the color value (AI) is As described above, from Bx (degree of Brix) and absorbance at 560 nm (ABS),
Bx was measured using a refractometer for measuring Bx, and pH was measured using a pH meter.

In the following, unless otherwise specified,%
Is% by weight.

Embodiment 1 1. Step of Preparing Sugar Syrup Large foreign substances in sugar cane juice (Bx21.2, pure sugar ratio 84.5%, pH 5.5) obtained by squeezing sugar cane with a squeezing machine were removed with a screen having a slit size of 0.1 mm. Thereafter, the mixture was heated to about 70 ° C. with a plate heater, and then a tubular ultrafiltration having a molecular weight cut off of 100,000 (Daicel Chemical Industries, Ltd.)
MH-25, effective area: 2 m ² × 30). Fine liquor (Bx), which is a sucrose solution, was added to the filtered cane juice (Bx19.8, pure sugar ratio 84.5).
58.0, pure sugar ratio 99.3%) and sugar syrup (Bx28.0, pure sugar ratio 91.2%) in a blend tank.
Was adjusted. 2. Concentration Step Next, the sugar syrup was heated and concentrated from Bx28.0 to Bx40.0 in the first plate heat exchanger. Under reduced pressure, the concentrated liquid was separated from the vapor by a vapor separator, and the concentrated liquid was sent to the second plate heat exchanger, where it was heated and concentrated from Bx40 to Bx65.
Further, under reduced pressure, the concentrated liquid was separated from the vapor by a vapor separator, and the concentrated liquid was heated and concentrated from Bx65 to Bx93 by a third plate heat exchanger. The Bx93 concentrated liquid was separated from steam under a normal pressure by a vapor separator. The measurement of Bx at this time was obtained from a conversion table of the relationship between the liquid temperature of the sugar solution under normal pressure and Bx. That is, the outlet temperature of the concentration of the third plate heat exchanger (the temperature at the inlet of the vapor separator) is about 1
Since it was 27 ° C., a value of Bx93 was obtained. 3. Crystallization Step The sugar syrup concentrated up to Bx93 was introduced into a horizontal continuous crystallizer (Turbulizer, manufactured by Hosokawa Micron Corp., 800 rpm, 30 inch paddle) with a high-speed rotating paddle.
Solidified. At this time, the operating conditions of the horizontal continuous crystallizing machine with the high-speed rotating paddle were such that the peripheral speed was 32 m / sec, and the relative humidity of the heated dry air introduced into the crystallizing machine was 4.5% (temperature of about 85%).
° C), and the air volume was adjusted to 12 Nm ³ / min (the air volume of dry air when the horizontal continuous crystallizer with a high-speed rotating paddle was operated at a discharge speed of 1 ton / hour of granular sugar). The sugar syrup concentrated under such conditions was subjected to strong shearing force by a rotating paddle inside a horizontal continuous crystallizer equipped with a high-speed rotating paddle and solidified at a stretch. Thus, about 1.
It was possible to produce granular sugar with a production capacity of 1 t / hour. At this time, the temperature of the granular sugar when coming out of the horizontal continuous crystallizer with the high-speed rotating paddle was about 110 to 120 ° C, the pure sugar ratio was 90.6, and the water content was 2.0%. 4. Drying Finishing Step The granular sugar obtained in step 3 is passed through a screw conveyor (having a structure that efficiently removes steam generated from the granular sugar by ventilation (suction and pushing in air)) to a temperature of about 45 ° C (relative humidity 25%), granular sugar 30
It was introduced into a hopper that had been blown with 15 m ³ / min dry air per ton. In addition, the temperature of the granular sugar when entering the hopper from the screw conveyor was about 100 ° C., and the water content was 1.5%. Further, the drying and finishing steps in the hopper, that is, the drying, cooling and aging steps, were performed until the water content of the granular sugar reached a sufficient equilibrium water content, that is, over 24 hours. The water content of the granulated sugar after aging was 0.8%. Subsequently, the particles were sieved with a sieving machine (having a 16-mesh net) in order to make the particle diameter uniform, and the sieved portion was used as a granular sugar product (A). 5. Characteristics of the product The granular sugar thus obtained has a pure sugar ratio of 90.6%, a water content of 0.8%, a color value (AI) of 1030, and is a yellow-white granular sugar having the natural flavor of cane sugar. Was. This granular sugar had excellent characteristics that it was excellent in fluidity and hard to solidify. Comparative Example 1 A sugar syrup was prepared in the same manner as in Step 1 of Example 1, except that the pure sugar ratio of the obtained sugar syrup was adjusted to 85.8%. Then, steps 2 and 3 of Example 1 were repeated. However, in step 3, the solidified solid and the solidified solid partially came out of the turbulizer at the same time, and the adherence of solids inside the turbulizer became remarkable. The production speed at the burizer gradually decreased. Further, when the solidification is incomplete as described above, the process proceeds to the next step 4, and when it is put into a hopper from a screw conveyor, consolidation is likely to occur, and the drying and finishing step becomes longer than that in Example 1. Also, no satisfactory product was obtained. Thus, it was found that when the pure sugar rate was low, continuous industrial production was difficult.

Comparative Example 2 A sugar syrup was prepared in the same manner as in Step 1 of Example 1, except that the pure sugar ratio of the obtained sugar syrup was adjusted to 95.7%. Then, steps 2 and 3 of Example 1 were repeated. When the solidified granular sugar was advanced to step 4 and put into a hopper from a screw conveyor, consolidation was apt to occur in the hopper, and the drying and finishing step could not be performed stably. In addition, the temperature of the granular sugar when entering the hopper from the screw conveyor was about 100 ° C., and the water content was 1.5% by weight. As described above, it was found that when the pure sugar ratio was high, the granular sugar was likely to solidify in the hopper in the drying and finishing step. In addition, the granulated sugar was liable to solidify during storage.

Comparative Example 3 Steps 1 to 3 of Example 1 were repeated. Next, instead of step 4 (drying with a hopper, cooling and aging) of Example 1, a conventional drying finishing step (drying with a dryer,
(Cooling by a cooler and aging by a hopper). That is, the granular sugar obtained from step 3 (temperature 40
-45 ° C, water content 0.9% by weight) by using a fluidized bed dryer (MDD-3000N, manufactured by Fuji Paudal Co., Ltd.) into which hot air of about 60 to 70 ° C is blown. 0.
After drying to 7%, the temperature of the granulated sugar is reduced to approx.
The mixture was cooled to 0 to 35 ° C. and aged in a hopper for 24 hours until the water content of the granular sugar reached a sufficient equilibrium water content. After the ripening, the particles were sieved with a sieving machine to make the particle size uniform, thereby obtaining a granular product (B).

The granular sugar thus obtained has a pure sugar ratio of 90.
It was a yellow-white granular sugar having 5%, water content of 0.7% and a color value (AI) of 1120, and having the natural flavor of cane sugar.

Test Example A load test was carried out on the granular product (A) obtained in Example 1 and the granular product (B) obtained in Comparative Example 3, and as a result, the differences shown in Table 1 below were observed. .

The load test was carried out as follows: Products A and B were each placed in a product pouch (OP
(20μm / PE60μm), 2 bags at a time, apply a 120kg load (equivalent to the bottom of a 12kg stack with a 20kg large bag) to the area of 4 small bags, take out at 1st month and 2nd month I decided to see it.

[0048]

[Table 1]

From the above results, the granular sugar product dried and finished by the method of the present invention (one step by a hopper) is as follows:
Compared with the conventional method (three steps of drying, cooling and aging), not only the steps were simplified and the equipment cost was reduced, but also differences in the physical properties of the products were found due to the different drying methods. . That is, the granular sugar product obtained by the method of the present invention and the granular sugar product obtained by the conventional method have almost the same water content, but the granular sugar obtained by the conventional method is In a two-month load test, caking had started slightly, though slightly, as compared with the granular sugar obtained by the method of the present invention.

The process according to the invention dries the granular sugar slowly with dry air. Granular sugar is composed of crystals one by one surrounded by a nectar (honey part), but by such slow drying, microscopically, sucrose in each nectar is Crystallization is sufficiently promoted,
It will be in a stabilized state. Macroscopically, there is an effect that the noncrystalline portion (honey portion) becomes uniform and stable without localization, and the amount of the noncrystalline portion is minimized as the whole granular sugar. As described above, in a state where the whole granular sugar is homogenized, the transfer of water in the granular sugar hardly occurs, so that the solidification hardly occurs. On the other hand, in the conventional method, since the crystal on the surface of the granular sugar is rapidly dried by the dryer, the crystallization of the sucrose in the honey film existing inside the granular sugar cannot be promoted, and the non-crystalline portion is reduced. Many and not in a stable state. Therefore, it is presumed that the moisture in the non-crystalline portion promotes the recrystallization of sucrose during storage, and consolidation occurs while involving the surrounding granular sugar.

As described above, when the drying and finishing step is performed in a single step using a hopper, since the noncrystalline portion is present in a very stable state in the dried granular sugar, the conventional drying method (3)
It is expected that the granular sugar product is less likely to solidify as compared to step).

Application Example 1 Here, in step 4 of the method of the present invention, the relationship between the relative humidity of the dry air in the hopper and the water content of the granular sugar product, and the relationship between the water content of the granular sugar product and the caking property Investigated the relationship.
From the results, the optimum water content of the granular sugar product was determined, and further, to obtain such a water content, the optimum water content of the granular sugar before entering the hopper was examined. (1) Examination of relative humidity Steps 1 to 3 of Example 1 were repeated. The granulated sugar solidified in step 3 was introduced into a hopper via a screw conveyor. The temperature of the granular sugar when entering the hopper from the screw conveyor is about 100 ° C., and the water content is 1.6.
% By weight. The hopper has a temperature of about 45 ° C. and a relative humidity of 25, 30, 35, 40, 45, 5 respectively.
0 or 60% air was pumped in from the bottom. The drying and finishing step was performed until the water content of the granulated sugar reached a sufficient equilibrium water content, that is, over 24 hours. The following table shows the relationship between the relative humidity of the dry air and the water content of the granular sugar after the drying and finishing step.

[0053]

[Table 2] (2) Load test Each of the products (a) to (g) obtained in (1) was subjected to a load test, and the following results were obtained.

The load test was performed in the same manner as in Comparative Example 3.

[0055]

[Table 3] ─────────────────────────────────── Product 1 month status 2 month status ─────────────────────────────────── (a) No consolidation was observed No consolidation Not observed (b) No consolidation was observed No consolidation was observed (c) No consolidation was observed No consolidation was observed (d) No consolidation was observed Not observed Slight consolidation was observed (e) Slight consolidation was observed Slight consolidation was observed (f) Slight consolidation was observed Slight consolidation was observed ( g) Consolidation was confirmed Consolidation was recognized ─────────────────────────────────── Above From the results of In view of the in-situ consolidation, it has been found that the granulated sugar product is preferably dried to 1.3% by weight or less in the hopper. (3) Examination of Water Content of Granular Sugar Before Entering Hopper Steps 1 and 2 of Example 1 were repeated. In step 3,
With respect to the granular sugar solidified by the horizontal continuous crystallizer equipped with a high-speed rotating paddle under the same conditions as in Example 1, the water content immediately before entering the hopper via a screw conveyor for sucking extra vapor was 2 .5, 2.0, 1.6, 1..
Adjusted to 3 or 1.0%. The state of these granulated sugars in the hopper was observed, and the results are shown in the following table. The condition of the dry air sent from the bottom of the hopper is
Same as Example 1.

[0056]

[Table 4] 水分 Moisture (%) Condition in hopper ───────── ２．５ 2.5 Consolidation was observed 2.0 Consolidation was slightly observed (surface solidification) 1.6 Consolidation was observed No 1.3 No consolidation 1.0 No consolidation ─────────────────────────── Above According to the results of the above, the water content of the granular sugar before entering the hopper is not more than 2.0% by weight, more preferably not more than 1.6% by weight in performing the drying and finishing step by the hopper. It turned out to be preferable in performing the finishing step.

Application Example 2 Here, the optimum conditions for the ultrafiltration performed in Example 1 were examined.

In step 1 of Example 1, a tubular ultrafiltration (manufactured by Daicel Chemical Industries, Ltd., effective membrane area 2 m ² × 3)
Molecular weight of 10,000, 30,000, 40,000 and 10
The cane juice was filtered at 10,000, 150,000 or 500,000. Fine liquor is mixed with the filtered cane juice, and the pure sugar ratio of each is 91.0% in a blend tank.
The sugar syrup was adjusted to be. In step 2, these sugar syrups were converted to Bx using a plate heat exchanger.
After concentrating to 93, the vapor and the concentrated solution were separated by a vapor separator. Next, in step 3, solidification was performed using a horizontal continuous crystallizer equipped with a high-speed rotating paddle (Turbulizer, manufactured by Hosokawa Micron Corp., 2800 rpm, 8 inch paddle, peripheral speed 29.8 m / sec). Then
In step 4, a dry finish was performed with a hopper. The conditions of steps 3 and 4 were the same as in example 1.

[0059]

[Table 5] ─────────────────────────────────── Molecular weight cutoff Permeation speed Horizontal continuous with high-speed rotating paddle Drying by hopper (kg, solid content Immediately after leaving the crystallizer / time, m ² ) ──────────────────────────── ─────── 10,000 3.0 Total solidification (granular) Possible (no consolidation) 30,000 4.5 Total solidification (granular) Possible (no consolidation) 40,000 5.4 Total solidification (Granular) Possible (no consolidation) 100,000 8.3 Total solidification (granular) Possible (no consolidation) 150,000 12.5 Total solidification (granular) Possible (non-consolidating) 500,000 6 Cannot solidify partly Not possible (easy to consolidate) よ う Like this The molecular weight cut off is 150,000 or less It was found that solidification could be achieved by using a continuous continuous crystallizer equipped with a high-speed rotating paddle using sugarcane juice filtered using a tubular ultrafiltration membrane. Further, drying by a hopper could be performed without any problem. However, the production speed
When the molecular weight cut-off of the tubular ultrafiltration membrane was less than 30,000, it was found that the production rate was reduced due to the reduced filtration rate of cane juice.

Further, when the sugar cane juice filtered using a tubular ultrafiltration membrane having a molecular weight cut-off of more than 150,000 and solidified using a horizontal continuous crystallizer equipped with a high-speed rotating paddle,
In some cases, solidification was not possible. That is, when a filtration treatment is performed using a tubular ultrafiltration membrane having a molecular weight cutoff of more than 150,000, high molecular impurities derived from sugar cane and a suspended substance that inhibit solidification are still contained. It is estimated to be.

APPLICATION EXAMPLE 3 Here, an optimum range of the peripheral speed was examined when using a horizontal continuous crystallizer with a high-speed rotating paddle.

In Step 3 of Example 1, the peripheral speed of the horizontal continuous crystallizer with the high-speed rotating paddle was set to 15, 20, 25, 30,
Each step of Example 1 was repeated, except that it was changed to 35, 40, 45, or 50 m / sec. The state immediately after the granular sugar left the crystallizer and the drying state in the hopper were observed.

[0063]

[Table 6] 周 Crystal machine peripheral speed Horizontal continuous crystal with high-speed rotating paddle Immediately after the hopper dries (m / s) ────────────────────────────────── 15 Partially solidified and creamy. Cannot be dried. 20 Total solidification Dryable (partially consolidated) 25 Fully solidified Dryable (no consolidation) 30 Fully solidification (particle size distribution is in place) ) Can be dried (does not consolidate) 35 Solidified (solidified) Particles can be dried (not consolidated) 40 Solidified (solidified) 40 Can be dried (does not solidify) 45 Solidified Can be dried (does not solidify) 50 Solidified but often powdery ────────────────────────────────── よ り From the results in Table 6 above, in the crystallization process, It was found that the peripheral speed of the attached horizontal continuous crystallizer was preferably 25 to 45 m / sec. Peripheral speed too low (20m / sec)
In such a case, the shearing force is weakened, and complete solidification is not achieved. On the other hand, if the peripheral speed is too high (50 m / sec), the solidified sugar forms a fine powder rather than a granule, and the fine powder is formed in a hopper in the next drying and finishing step. By sending dry air, dust tends to form and operability is poor.

When the peripheral speed is set to 30 to 40 m / sec, the particle size distribution tends to be uniform, so that it is more preferable from the viewpoint of the drying finishing step or from the viewpoint of fluidity and consolidation.

[0065]

According to the present invention, in the conventional method for producing granular sugar, the drying and finishing step, which is an important step for determining the quality of a sugar product, that is, the three steps of a dryer, a cooler and a hopper, are performed only in a hopper step. It could be simplified. No need for dryer and cooler,
Equipment costs can be saved and the installation area can be reduced. Furthermore, the granular sugar obtained by the method of the present invention contains flavor and nutrient components derived from cane sugar, is hardly colored, has good fluidity, and is easy to handle, such as being hardly consolidated.

[Brief description of the drawings]

FIG. 1 shows an apparatus for carrying out the method of the present invention and main manufacturing steps used in Example 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cane juice 2 Screen 3 Plate heater 4 Ultrafiltration 5 Blend tank 6 Plate type heat exchanger 7 Vapor separator 8 Horizontal continuous crystallizer with high-speed rotating paddle 9 Drying conveyor 10 Hopper 11 Dry air 12 Sieving machine 13 Product

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Tadashi Ebashi 6-29-1-1-418 Minamiruyama, Nagareyama City, Chiba Prefecture (72) Inventor Kozo Yamada 2-5-1-405 (72) ) Inventor Toshiaki Sugitani 2-5-1-301 Kobuya, Kamakura City, Kanagawa Prefecture (72) Inventor Masaaki Kodomari 2-25-3-407 Ikegami Shinmachi, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture

Claims (10)

[Claims] 1. a step of preparing a sugar syrup, a step of concentration,
In the method for producing granular sugar including a crystallization step and a dry finishing step, the pure sugar ratio of the sugar syrup obtained through the step of preparing the sugar syrup before entering the concentration step is 87.0 to 95.1% by weight. The crystallization step is a step of obtaining granulated sugar by solidifying while applying a strong shear force, and the drying and finishing step is a step in which the granular sugar obtained from the crystallization step is A process for drying by sending the dried air into a hopper to which dried air is sent. 2. The sugar syrup before the concentration step is subjected to ultrafiltration of sugar cane juice having a cut-off molecular weight of 30,000 to 150,000, followed by addition of sucrose and / or a sucrose solution to obtain a pure sugar rate of 87.
The method according to claim 1, which is obtained by adjusting the amount to 0 to 95.1% by weight. 3. The method according to claim 1, wherein in the crystallization step, solidification is performed while applying a strong shearing force to obtain granulated sugar using a horizontal continuous crystallizer equipped with a high-speed rotating paddle. 4. The method according to claim 3, wherein the sugar syrup that has passed through the concentration step has a Brix degree (Bx) of 90.5 to 95.3. 5. The method according to claim 3, wherein in the crystallization step, the peripheral speed of the horizontal continuous crystallizer with a high-speed rotating paddle is 25 to 45 m / sec. 6. In the crystallization step, heated dry air is introduced into a horizontal continuous crystallizer equipped with a high-speed rotating paddle, and the heated dry air has a relative humidity of 10% or less, and
When the horizontal continuous crystallizer with a high-speed rotating paddle is operated at a discharge speed of 1 ton / hour of granular sugar, the air volume of dry air is 9 to 30.
The method of any one of claims 3 to 5 is Nm ³ / min. 7. A conveyor is used to transport the granular sugar solidified in the crystallization step to a hopper in a dry finishing step, and the conveyor is generated from the granular sugar during transport of the granular sugar. The method according to any one of claims 1 to 6, further comprising means for efficiently removing steam by ventilation, wherein the granular sugar has a water content of 2.0% by weight or less immediately before entering the hopper. 8. The method according to claim 1, wherein the drying air in the drying finishing step has a temperature of 40 to 50 ° C. and a relative humidity RH of 35% or less. 9. The method according to claim 1, wherein the granular sugar is dried to a moisture content of 0.4 to 1.3% by weight in the drying and finishing step. 10. The method according to claim 9, wherein in the drying and finishing step, the granular sugar is dried to a water content of 0.4 to 0.9% by weight.