JPH02174650A - Preparation of granular dipeptide sweetener - Google Patents

Abstract

PURPOSE:To prepare a granular dipeptide sweetener having high purity and excellent fluidity and solubility by spray-drying a slurry of a dipeptide sweetener without using a crushing operation, granulating the dried product and, as necessary, further drying the granules. CONSTITUTION:A slurry liquid containing crystals of an alpha-L-aspartyl-L- phenylalanine lower alkyl ester is spray-dried to obtain a dried product having extremely poor fluidity and containing a large amount of fusiform fine powder of <=10mum in length. The dried product is granulated preferably by fluidized granulation and dried according to the need.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a method for producing a granular dipeptide sweetener, and more specifically, it relates to a method for producing a granular dipeptide sweetener, and more specifically, it relates to a method for producing a granular dipeptide sweetener, and more specifically, it relates to a method for producing a granular dipeptide sweetener. The present invention also relates to a method for producing a granular dipeptide sweetener with good solubility.

[Prior Art] Dipeptide sweeteners represented by α-L-aspartyl-L-phenylalanine lower alkyl esters, particularly methyl esters, have already come to occupy an important position as low-calorie sweeteners.

The dipeptide H flavoring agent is generally used in the form of an aqueous solution or in the form of a powder, tablet, etc. along with other ingredients as necessary.

Dipeptide "Compounds used as flavoring agents, such as α-
L-aspartyl-L-phenylalanine methyl ester is ultimately produced industrially in the form of a solid such as a powder in view of its storage stability. However, since the solid α-L-aspartyl-L-phenylalanine methyl ester obtained by conventional methods has a slow dissolution rate in water, it is necessary to use dipeptides with good solubility in the production of products containing such flavoring ingredients as aqueous solutions. Sweetener required.

Furthermore, even when a dipeptide H flavor agent is used in powder form, the flavor is not exhibited until it is dissolved in water, so a dipeptide H flavor agent that dissolves quickly in water is required.

For this reason, various attempts have been made to improve the solubility in water. These attempts can be broadly divided into two types: one attempts to reform the sweetener by changing its crystal structure, and the other attempts to change the shape of the dried 14' flavoring agent. be.

Examples of old names include JP-A-63-44593 and others. This method can be expected to be quite effective, but due to the chemical and physical properties of the α-L-aspartyl-L-phenylalanine alkyl ester molecule, it can only be improved to a certain extent, and is used for foods that require extremely rapid solubility. cannot be said to be sufficient.

This is because even in the case of a soluble crystalline structure, the dissolution rate of 1- is greatly affected by the properties of the dry seasoning powder.

An example of the prior art of the latter method to which the present invention pertains is US Pat. No. 4,517, 2145/1985.
．． 5hoaf et al. This method is
Although it is an effective method for producing dry products of α-L-aspartyl-L-phenylalanine alkyl ester with high purity, it is extremely difficult and expensive to use wet grinding operations, especially ultrafine grinders, for food additives. Technical skills are required.

[Problem to be solved by the invention] Generally, when a dry product is industrially produced in large quantities from a slurry liquid, and this product is required to have a high dissolution rate,
Spray drying is considered to be the most popular method. In other words, if we consider drying the raw materials using this method, the product will become porous and spherical, and we can expect improvements in solubility and solubility.
When drying large quantities, the surface area per object to be dried becomes very large, so spray dryers have the advantage of being economically advantageous because they have much better drying efficiency than other dryers. be.

The first obstacle in implementing this method is that if spherical particles are to be used, the solid particles constituting the raw slurry must be very small compared to the product particles. Considering the practical size of the spray dryer, the product particles should have a maximum diameter of several hundred micrometers, preferably 2.
00 micrometers or less, and when trying to make the product porous and spherical, in slurry liquid spraying, the particles constituting the slurry have a diameter of χ, t L, preferably 20% or less,
Particularly preferably, the content should be 5% or less. On the other hand, considering the size of the crystals of α-L-aspartyl-L-phenylalanine alkyl ester that constitutes the spray raw material slurry liquid, it is clear that wet pulverization is necessary, but with the current technology, this is not possible. For pulverization, a media agitation type pulverizer must be used, and in principle, this type of pulverizer cannot avoid wear of the pulverizing media, and requires various devices to prevent this.

The shape of the spray-dried product is ``spray'' unless it undergoes a pulverization operation.
f')i Large a-L present in II material slurry
The crystals of aspartyl-phenylalanine alkyl ester form a long spindle-like structure, and they are more likely to be broken during drying than spherical particles, resulting in the generation of a larger amount of fine powder (several micrometers) and the product quality. Fluidity deteriorates significantly.

The second obstacle is that the crystals of α-L-aspartyl-L-phenylalanine alkyl ester have crystallization water or blue water, and spray drying, in which the drying time is very short and the air humidity near the dryer outlet is very high, is insufficient. Drying to the required moisture content is extremely difficult. In order to solve this problem, setting the exhaust air temperature during spray drying to a high level is effective in lowering the water content tf, but it also creates a type of crystal with poor solubility and α -L
-Aspartyl-L-phenylalanine alkyl ester is known to be impractical due to its poor thermal stability.

The purpose of the present invention is to provide a method for producing a flavoring agent of high purity, fluidity and good solubility, α-L-aspartyl-L-phenylalanine alkyl ester 1↑, which has been difficult to obtain in the past, into a container. It is in.

Means for Solving the Problem] As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have found that by adding a fluidized granulation operation in which co-acid is sprayed after spray drying, the difficult pulverization operation can be solved. We succeeded in producing α-L-aspartyl-L-phenylalanine alkyl ester 11 flavoring agent with good fluidity and solubility.

The gist of the present invention is to spray-dry without using a pulverization operation, then granulate it, and further dry as necessary to produce α-ri-Asbalthyl-L-
The purpose is to produce a phenylalanine alkyl ester sweetener. That is, the present invention is characterized in that a slurry liquid containing crystals of α-L-aspartyl-L-phenylalanine lower alkyl ester is spray-dried, the obtained dried product is granulated, and if necessary, it is re-dried. The present invention provides a method for producing a granular dipeptide sweetener. The details will be explained below.

The dry flame slurry used in the present invention has relatively large particles, but when crystals are precipitated from a complete solution in the LI process of purification, the cohesive force of the crystals results in agglomerated needle-shaped crystals. , the major axis becomes 50 micrometers or more. In the present invention, the slurry is spray-dried as it is, or merely repulped by adding water to facilitate spraying, that is, without pulverization.

The product obtained here has very little contamination by foreign matter due to pulverization, but since it is spindle-like and contains a large amount of fine powder, its fluidity is extremely poor, and the moisture content of the product is low.
It is usually 4 to 10%.

In the present invention, next, granulation, preferably fluidized granulation, and, if necessary, drying are performed. The spray liquid used in the fluidized granulation operation is water, an aqueous solution of α-L-aspartyl-L-phenylalanine alkyl ester, a sugar solution, and an aqueous solution (including slurry) of other substances that can be used as a binder, and a subsequent drying operation is performed as necessary. Fluidized drying, vacuum drying, etc. can be used. However, in order to prevent the destruction of the granulated material, it is preferable to use a method in which the movement of the material to be dried is minimized.

Example 1 A slurry liquid in which crystals were precipitated from an aqueous solution of α-L-aspartyl-L-phenylalanine methyl ester was concentrated by operation to remove the solid-liquid content, and this was repulped while adding water cooled to 4°C, and then sprayed. The dry raw material slurry was prepared for 33 minutes. The constituent particles of this raw material slurry were aggregates of needle-like crystals, each having a length of about 10 to 30 micrometers.This slurry was sprayed at an inlet temperature of 170°C and an outlet temperature of 75°C. It was dried and all the products were collected.The dried product showed a particle size distribution with two peaks, one large and one small, with a volume average diameter of around 75 micrometers and around 5 micrometers, and the particle shape was 30 micrometers in diameter. Most of the following are needle-like,
Anything larger than this became a long spindle filament with the nucleus being a large α-L-aspartyl-L-phenylalanine methyl ester crystal present in the spray raw material slurry. This product was processed in a fluidized granulator for 1. ．． 096a-L-Aspartyl-L-phenylalanine methyl ester aqueous solution was sprayed and flowed for 10 minutes.

Furthermore, spraying was stopped using the same machine, and fluidized drying was performed for 10 minutes. The ground product was evaluated for particle size and physical properties as shown in the table below.

Table 1 Dry laser particle size /li,; Values according to l 2nd table As a result, a spindle-like product and a large amount of fine powder are aggregated and granulated, and the eyelid granules with good fluidity and solubility contain moisture. A product having an a content of 2 to 4% based on the product can be referred to as f'I. This product is excellent as a food additive.

Hon Carl (C+lrr), Chemical Engineering (CI+a*Ical IEnglnccrlng
), January 18, 1965, pp. 166-167 Tables 1 and 2 show that granulation sharpens the particle size distribution at the poles;
It can also be seen that the fluidity was greatly improved.

[Effect of the invention]

Claims (1)

[Claims] (1) A granular form characterized by spray-drying a slurry containing crystals of α-L-aspartyl-L-phenylalanine lower alkyl ester, granulating the obtained dried product, and re-drying as necessary. A method for producing a dipeptide sweetener.