Method for producing starch decomposition product

Abstract

To provide a method for producing a starch decomposition product that is prone to aging, which minimizes problems, such as aging and gelation during the manufacturing process.SOLUTION: The foregoing problems are solved by subjecting starch to oxidation or acid treatment to make components with a molecular weight of 105 or more constitute 22-60 mass% of the sugar composition, followed by decomposing the starch with a branching enzyme to make components with a molecular weight of 103-104 constitute 30-50 mass% of the sugar composition.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a method for producing starch hydrolysates that are susceptible to retrogradation. [Background technology]

[0002] Starch hydrolysates have been used in food and beverages for a long time. For example, starch hydrolysates obtained by mildly hydrolyzing starch are used to add body to food and beverages or as a powder base material. Such mildly hydrolyzed starch hydrolysates tend to retrograde (become cloudy) over time even when dissolved in water, which can adversely affect the appearance and texture of food and beverages. On the other hand, it is known that these easily retrograded starch hydrolysates can be used as clouding agents and shape retention improvers for food and beverages.

[0003] As a method for producing such starch hydrolysates that easily retrogradate, Patent Document 1 discloses a method in which a heat-stable α-amylase is added to a starch suspension, hydrolysis is carried out at 70 to 100° C., and the reaction is stopped when the blue value (absorbance at 680 nm) reaches 0.4 to 1.2. Generally, to obtain a starch hydrolysate that is highly effective as a clouding agent or shape retention improver, it is necessary to lower the degree of decomposition, but starch hydrolysates with a low degree of decomposition obtained by decomposition only with α-amylase, as in this production method, have the problem that they retrograde and gel during the production process, resulting in poor workability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-11781 A Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a method for producing starch hydrolysates that easily undergo retrogradation, while minimizing the inconvenience of retrogradation and gelation during the production process. [Means for solving the problem]

[0006] The inventors have conducted various studies to solve such problems. As a result, they have found that by oxidizing or acid-treating starch so that the component with a molecular weight of 10 5 or more accounts for 22 to 60% by mass in the sugar composition, and then decomposing it with a debranching enzyme so that the component with a molecular weight of 10 3 to 10 4 accounts for 30 to 50% by mass in the sugar composition, it is possible to obtain a starch degradation product that is prone to aging without causing inconvenience in workability during the manufacturing process.

[0007] That is, the present invention has been completed based on the above findings and is composed of the following [1] to [6]. [1] A method for producing a starch degradation product, comprising oxidizing or acid-treating starch so that the component with a molecular weight of 10 5 or more accounts for 22 to 60% by mass in the sugar composition, and then decomposing it with a debranching enzyme so that the component with a molecular weight of 10 3 to 10 4 accounts for 30 to 50% by mass in the sugar composition. [2] The method for producing a starch degradation product according to [1], wherein the starch is potato starch. [3] The method for producing a starch degradation product according to [1] or [2], wherein the starch degradation product satisfies the following (A) and (B): (A) The total of DP1 to 7 in the sugar composition is 5% or less, (B) 10 3 <N (molecular weight) ≤ 10 4 is 30 to 50% by mass. [4] The method for producing a starch degradation product according to any one of [1] to [3], wherein the starch degradation product satisfies the following (C): (C) The turbidity after holding an aqueous solution of Brix 5 at 5°C for 60 minutes is 0.15 or more. [5] The method for producing a starch degradation product according to any one of [1] to [4], wherein the starch degradation product is for clouding or improving the shape retention of food and drink products. [6] A clouding agent or shape retention improver for food and drink products, comprising a starch degradation product obtained by the production method according to any one of [1] to [4]. [Advantages of the Invention]

[0008] According to the method of the present invention, a novel starch hydrolysate having a tendency to easily retrogradate can be easily provided without causing inconvenience in the workability in the production process. Furthermore, since the starch hydrolysate obtained by the method of the present invention is prone to gelation, it can be suitably used for improving the shape retention of semi-solid foods and beverages for which transparency is not particularly important. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Generally, starch hydrolysates are starch hydrolyzed with an acid or an enzyme, and this category includes substances called starch syrup, powdered syrup, dextrin, maltodextrin, etc., but the starch hydrolysates described in this specification include not only raw starch but also processed starch hydrolyzed with an acid or an enzyme, and the starch hydrolysates of the present invention are processed starch, specifically oxidized starch or acid-treated starch, hydrolyzed with an enzyme.

[0010] There is no limitation on the starch used as a raw material for the above-mentioned processed starch used in the production of the starch hydrolysate of the present invention, and any starch extracted from plants such as corn, waxy corn, sweet potato, wheat, glutinous barley, non-glutinous rice, glutinous rice, potato, waxy potato, tapioca, waxy tapioca, sago, and pea can be used, but from the viewpoint of workability (aging resistance) in the production process, it is preferable to select potato starch.

[0011] The method for producing a starch hydrolyzate of the present invention is characterized in that starch is oxidized or acid-treated and then hydrolyzed with a debranching enzyme. 5 The sugar composition is characterized in that the above components are adjusted to 22 to 60% by mass, preferably 25 to 50% by mass. 5 If the above components are less than 22%, the desired starch hydrolyzate cannot be obtained even if it is subsequently decomposed with a debranching enzyme, and the molecular weight of the starch is 10 5If the above components exceed 60%, the viscosity of the reaction solution will be high, making it difficult to decompose with the debranching enzyme, and subsequent powderization will be difficult. Note that hereafter, molecular weight will sometimes be simply expressed as "N".

[0012] The aforementioned "molecular weight 10 5 The content of the above components in the sugar composition can be determined from the molecular weight distribution obtained by high performance liquid chromatography using gel filtration. Specific analytical conditions are, for example, as follows. From the calibration curves of molecular weight versus detection time for pullulan standard, maltotriose and glucose, the molecular weight of 10 5 The detection time of the peak was calculated, and the peak area percentage detected before that detection time was calculated as "molecular weight 10 5 The content of the above components in the sugar composition can be used as the content. [Column]: TSKgel G6000PWXL, G3000PWXL, G2500PWXL (Tosoh Corporation), [Column temperature]: 80 ° C. [Mobile phase]: 0.1M NaNO3, [Flow rate]: 0.5mL / min, [Detector]: Differential refractometer, [Sample injection volume]: 100 μL of 1% by mass aqueous solution, [Calibration curve]: Pullulan standard (Showa Denko K.K.), maltotriose and glucose According to the above method, the molecular weight of the 10 3 ~10 4 The content of the "component" in the sugar composition can also be determined in the same manner.

[0013] molecular weight 10 5To obtain oxidized starch in which the above components account for 22 to 60% by mass in the sugar composition, for example, a 15 to 45% (w / w) starch suspension is adjusted to pH 10.5 to 11.5 with an alkaline agent (e.g., sodium hydroxide), sodium hypochlorite is added to the starch solid content at 20,000 ppm to 80,000 ppm, and the mixture is reacted at a temperature of 20 to 50° C. for about 1 to 8 hours. The amount of sodium hypochlorite to be added is preferably 20,000 ppm to 60,000 ppm, more preferably 20,000 ppm to 45,000 ppm, based on the starch solid content. The progress of the reaction can be stopped by adding sodium hydrogen sulfite to reduce sodium hypochlorite, and the mixture is neutralized with acid and washed with water to obtain the desired oxidized starch.

[0014] molecular weight 10 5 To obtain acid-treated starch in which the above components account for 22 to 60% by mass of the sugar composition, for example, the starch may be adjusted to a pH of 0.5 to 2 with an acid solution such as hydrochloric acid or sulfuric acid, reacted at a temperature of 30 to 60°C for about 5 to 24 hours, neutralized with an alkaline solution such as sodium hydroxide, and then washed with water.

[0015] The method for producing the starch hydrolysate of the present invention is to use the starch hydrolysate having a molecular weight of 10 5 The oxidized starch or acid-treated starch containing the above components in the sugar composition at 22 to 60% by mass is further characterized by a molecular weight of 10 3 ~10 4 The debranching enzyme is characterized in that the component accounts for 30 to 50 mass %, preferably 36 to 50 mass %, of the sugar composition. To decompose with the debranching enzyme to obtain such a sugar composition, for example, an aqueous suspension of 10 to 40% (w / w) solids of the oxidized starch or acid-treated starch obtained by the above-mentioned method is adjusted to pH 4 to 5.5, and a debranching enzyme is added to give a concentration of 1200 to 4800 NPUN (per 100 g of oxidized starch or acid-treated starch), and allowed to act at a temperature of 45 to 65° C. for about 15 minutes to 2 hours. As the debranching enzyme, pullulanase or isoamylase can be used, and preferably pullulanase can be used. Here, the unit "NPUN" is a unit expressing enzyme activity, and can be measured by the method described in U.S. Patent Application Publication No. 2004 / 0048247. When using pullulanase "Promozyme D6" manufactured by Novozymes, its activity is about 4000 NPUN / g, so in order to obtain 1200 to 4800 NPUN per 100 g of starch, about 0.3 to 1.2 g of "Promozyme D6" should be used.

[0016] The starch hydrolyzate solution thus obtained can be subjected to purification steps such as filtration through diatomaceous earth and desalting with an ion exchange resin, and then can be made into a powder product by spray drying or the like.

[0017] Here, the degree of starch decomposition can be expressed by the above-mentioned molecular weight, as well as the degree of polymerization of glucose, DP. For example, a pentasaccharide formed by polymerizing five glucose units is expressed as "DP5". Analysis of DP and its composition (ratio) is performed using high performance liquid chromatography as follows, and the composition is expressed as simple area %: [Column]: MCI GEL CK02AS (Mitsubishi Chemical Corporation) [Column temperature]: 80 ° C. [Mobile phase]: distilled water, [Flow rate]: 1mL / min, [Detector]: Differential refractometer, [Sample injection volume]: 100 μL of 1% by mass solution. In the starch hydrolyzate of the present invention, the total of DP1 to 7 in the sugar composition is 5% or less, preferably 3% or less, and the total of DP8 to 19 in the sugar composition is 10% or more, preferably 14% or more.

[0018] The starch hydrolysate produced by the method of the present invention is characterized by being easily clouded and retrograded. In the present invention, "easily retrograded" refers to the property of the starch hydrolysate becoming clouded within 60 minutes when added to and mixed with cold water at 5°C, specifically, the turbidity (10 times the absorbance at 720 nm measured with a cell length of 1.0 cm) of a 60°C starch hydrolysate-containing solution adjusted to Brix 5 after being kept in cold water at 5°C for 60 minutes is 0.15 or more. It can be said that the higher the turbidity value, the more preferable it is for improving the shape retention of semi-solid foods and beverages that do not place importance on transparency, but from the viewpoint of melting in the mouth when eaten, the upper limit is preferably 18.0 or less, more preferably 17.0 or less.

[0019] The types of food and drink in which the starch hydrolysate of the present invention can be used are not particularly limited, but it can be applied to foods to which it is desired to impart a cloudy texture and shape retention, such as ice cream, soft serve ice cream, milk pudding, custard cream, yogurt, mousse, cheese, white sauce, and other milk-containing foods, beverages, dessert mixes, etc. In particular, it can be suitably used as a shape retention improver for frozen desserts (a dissolution inhibitor at room temperature), and when it is added to a soft serve ice cream mix, for example, a soft serve ice cream that does not melt easily even at a high temperature of 35°C can be obtained. The content of the starch hydrolysate of the present invention in these foods and drinks is not particularly limited, but is, for example, 1 to 30 mass %, 2 to 15 mass %, or 3 to 10 mass %.

[0020] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these examples. In the examples, "%" means "% by mass" unless otherwise specified. EXAMPLES

[0021] Starch hydrolysates were prepared as follows. <Oxidation treatment> 1,000 g (solid content equivalent) of potato starch or corn starch was suspended in water to obtain a 43.5 mass% slurry, and the pH was adjusted to 11±0.5 using sodium hydroxide. Sodium hypochlorite was then added to the starch to give a concentration of 15,000 ppm to 100,000 ppm, and the mixture was allowed to react at 30°C for 4 hours. Sodium hydrogen sulfite was then added to reduce the remaining sodium hypochlorite and stop the reaction. The mixture was then neutralized with sulfuric acid, collected on filter paper, washed with water, and dried to obtain oxidized starches (samples No. A1 to A7).

[0022] <Debranching enzyme decomposition> 450 g of the oxidized starch obtained above was suspended in water to make a 15% or 30% slurry by mass, which was then heated at 121°C for 1 minute in an autoclave (Tomy Seiko Co., Ltd.) to make a paste. After lowering the temperature to 60°C, the pH was adjusted to 4.4 with 10% sulfuric acid, and pullulanase (Promozyme D6, Novozymes Japan) was added to the paste at 0.3%, 0.6%, or 1.2% of the raw material solids, and the mixture was added to the paste kept at 60°C and reacted for 75 minutes. The temperature was then raised to 85°C and held for 5 minutes to inactivate the enzyme.

[0023] <Powderization> The hydrolyzate was heated in an autoclave at 121° C. for 1 minute, and the heated liquid was powdered by spray drying to obtain starch hydrolyzates Nos. B1 to B7.

[0024] The starch hydrolysates were evaluated as follows. <Molecular weight distribution> The molecular weight distribution was confirmed by gel filtration chromatography using high performance liquid chromatography (HPLC) under the conditions shown in Table 1.

[0025] [Table 1]

[0026] <Sugar composition> The sugar composition was analyzed by high performance liquid chromatography (HPLC) using the columns shown in Table 2.

[0027] [Table 2]

[0028] <Evaluation of aging susceptibility> 5 mL of the starch hydrolysate-containing solution at 60°C adjusted to Brix 5 was placed in a test tube, placed in a 5°C water bath and held for 60 minutes, after which the absorbance (wavelength 720 nm, cell length 1.0 cm) was measured using a spectrophotometer (U-2900, Hitachi High-Technologies Corporation). The measured value was multiplied by 10 to determine the turbidity, which was evaluated according to the criteria in Table 3.

[0029] [Table 3]

[0030] <Analysis of starch hydrolysates> Samples Nos. A1 to A7 and B1 to B7 were analyzed by the above-mentioned method, and the results are shown in Tables 4 and 5.

[0031] [Table 4]

[0032] [Table 5]

[0033] <Result> molecular weight 10 5 When oxidized starches (A2-A5, A7) containing 22-60% by mass of the above components in the sugar composition were decomposed with pullulanase, starch hydrolysates (B2-1-B5, B7) that were more easily retrograded than commercially available starch hydrolysates (Smart Taste, a product of San-Ei Gen F.F.I. Co., Ltd.) were obtained. 5 When A1, in which the above components accounted for less than 22% by mass of the sugar composition, was used, no starch hydrolyzate that was prone to retrogradation was obtained, regardless of how the hydrolysis conditions with pullulanase were set (B1-1 to B1-3). 5When A6, which contains more than 60% by mass of the above components in its sugar composition, was decomposed with pullulanase, the viscosity of the decomposition liquid was too high to spray dry, and it was not possible to recover it as a powder (B6). From these results, in order to obtain starch hydrolysates that are prone to retrogradation, it is necessary to add a molecular weight of 10 5 It was found that it is necessary to oxidize starch so that the amount of the above components is 22 to 60% by mass. In addition, the sugar composition of the target starch hydrolyzates (B2-1 to B5, B7) that are prone to retrogradation is such that DP1 to 7 are 5% or less and the molecular weight is 10 3 ~10 4 The content of this component was 30 to 50 mass %. In addition, the solution of starch hydrolyzate (B7) obtained by hydrolyzing oxidized corn starch (A7) with debranching enzyme turned slightly white during production and retrogradation progressed, whereas the starch hydrolyzates (B2-1 to B2-3) obtained by hydrolyzing oxidized potato starch (A2) with debranching enzyme did not turn white during production. From the viewpoint of workability, it was found that potato starch is more preferable as a raw material than corn starch.

[0034] <Food example: soft serve ice cream> Using the starch hydrolysates of the present invention (B2-1, B2-2, B2-3, B4, B5) and a commercially available starch hydrolysate that easily retrogrades as a control (Smart Taste, manufactured by San-Ei Gen F.F.I. Co., Ltd.), soft serve ice creams were prepared according to the formulations in Table 6 and the procedures in Table 7. The shape retention of the obtained soft serve ice creams was evaluated by the following method. (Shape retention evaluation method) The soft serve ice cream was placed on a beaker with a wire mesh and allowed to stand in a thermostatic chamber at 35° C. After 10 minutes, the weight of the soft serve ice cream that had melted into the beaker was measured, and the melting rate (weight of the soft serve ice cream that had melted / total weight of the soft serve ice cream×100(%)) was calculated.

[0035] The results are shown in Table 8. The soft serve ice cream containing the starch hydrolysate obtained by the production method of the present invention had a lower melting rate and was richer and melted in the mouth better than the soft serve ice cream containing the control product. This shows that the starch hydrolysate obtained by the present invention can be used more preferably as a shape retention improver than the control product.

[0036]

Table 6

[0037]

Table 7

[0038]

Table 8

Claims

1. Molecular weight 10 ５ Starch is oxidized or acid-treated so that the above components account for 22 to 60% by mass of the sugar composition, and then the starch is mixed with a saccharide having a molecular weight of 10 ３ ~10 ４ The starch hydrolyzate is decomposed with a debranching enzyme so that the component accounts for 30 to 50 mass % of the sugar composition.

2. The method for producing a starch hydrolyzate according to claim 1, wherein the starch is potato starch.

3. The method for producing a starch hydrolysate according to claim 1 or 2, wherein the starch hydrolysate satisfies the following (A) and (B): (A) the total of DP1 to DP7 in the sugar composition is 5% or less; (B) 10 ３ <N (molecular weight)≦10 ４ is 30 to 50 mass %.

4. The method for producing a starch hydrolysate according to claim 1 or 2, wherein the starch hydrolysate satisfies the following (C): (C) The turbidity of an aqueous solution of Brix 5 after being kept at 5°C for 60 minutes is 0.15 or more.

5. The method for producing a starch hydrolysate according to claim 1 or 2, wherein the starch hydrolysate is used for making food or drink opaque or for improving its shape retention.

6. A clouding agent or shape retention improver for foods and beverages, comprising a starch hydrolysate obtained by the production method according to claim 1 or 2.

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