Method for producing a novel starch hydrolysate

Abstract

The objective of the present invention is to provide a method for producing a starch hydrolysate with low DE and high retrogradability in a low, simple, and efficient manner. By hydrolyzing a mixture of waxy starch and non-waxy starch mixed in a specific ratio, a starch hydrolysate with high retrogradability can be obtained in a low, simple, and efficient manner. Specifically, a starch raw material is hydrolyzed with an acid and / or α-amylase, wherein the mass ratio of waxy starch (mass ratio of solid content) to the total mass of waxy starch and non-waxy starch is at least 10 mass%.

Description

Technology Field

[0001] The present invention relates to a method for simply and efficiently producing a starch hydrolysate that is low DE and does not easily age. Background Technology

[0002] Starch hydrolysates have traditionally been used in food. These starch hydrolysates can be obtained as starch hydrolysates with a desired DE value by applying α-amylase (liquefaction enzyme), glucoamylase (saccharification enzyme), or acid to a starch suspension used as a raw material.

[0003] Generally, starch hydrolysates with low degradation, that is, starch hydrolysates with low DE values, are used in powdered foods such as seasonings and soup bases, and recently, they are also being used in nursing foods such as liquid diets and swallowing aids. However, starch hydrolysates with low DE values ​​pose a problem in that they age and become cloudy over time even after being dissolved in water, which adversely affects the appearance and texture of food.

[0004] Accordingly, methods for removing low molecular weight fractions are generally known in order to obtain starch hydrolysates with low DE values ​​that have high aging stability. For example, Patent Document 1 proposes a method of hydrolyzing raw starch to produce a stable starch hydrolysate with a DE of 20 to 40, and then separating low molecular weight sugars using a reverse osmosis membrane. In addition, Patent Document 2 discloses a method of treating amylopectin-containing starch with a special enzyme to increase α-1,6 bonds, and then fractionating maltodextrin with a molecular weight of about 20,000 to 50,000 daltons and a DE value of less than 8 by ultrafiltration.

[0005] Meanwhile, Patent Document 3 discloses that a starch hydrolysate with a DE value of 1.2 to 1.7 that does not easily age is obtained by two-stage hydrolysis of waxy tapioca starch with α-amylase under specific conditions without specifically undergoing a separation process for low molecular weight sugars. Prior art literature

[0006] [Patent Document 1] Specification of U.S. Patent No. 3,756,853 [Patent Document 2] Japanese Patent Application Publication No. Hei 6-209,784 [Patent Document 3] Japanese Patent Application Publication No. 2021-88623 The problem to be solved

[0007] However, the fractionation / removal of low molecular weight fractions requires the introduction of equipment such as fractionators, which incurs not only the burden of equipment costs but also problems such as increased complexity of the manufacturing process and reduced yield of the obtained starch hydrolysate, and there are also economic issues regarding the high cost of using special enzymes or waxy starch.

[0008] In addition, the starch hydrolysate obtained by the method of Patent Document 3 has a relatively high molecular weight, so its viscosity increases, which limits the types of food that can be used or makes it difficult to pass through a sterilization filter, and thus is prone to causing adverse effects.

[0009] Therefore, the objective of the present invention is to provide a method for producing a starch hydrolysate with low DE and high aging stability simply, inexpensively, and efficiently.

[0010] Another objective of the present invention is to provide a starch hydrolysate with low DE and high aging stability, and a starch hydrolysate with relatively low viscosity. means of solving the problem

[0011] The inventors first attempted to solve this problem by mixing a specific amount of a starch hydrolysate made from waxy starch with a starch hydrolysate made from relatively inexpensive non-waxy starch. However, the effect of improving retrogradation stability was very limited, so the expected effect could not be obtained. Accordingly, instead of mixing multiple starch hydrolysates afterward, they mixed them at the stage of the raw starch, that is, by mixing waxy starch in advance with non-waxy starch in a specific ratio, and then hydrolyzing it by applying acid and / or α-amylase, they discovered that a starch hydrolysate with low DE and high retrogradation stability could be obtained, leading to the completion of the present invention.

[0012] The present invention consists of the following [1] to [5].

[0013] [1] A method for producing a starch hydrolysate comprising a process of hydrolyzing a mixed suspension of waxy starch and non-waxy starch by applying one or more of an acid or α-amylase.

[0014] [2] A method for producing a starch hydrolysate according to [1] above, wherein the waxy starch is one or more selected from the group consisting of waxy tapioca starch, waxy corn starch, waxy potato starch and glutinous rice starch.

[0015] [3] A method for producing a starch hydrolysate, wherein, in [1] or [2] above, the non-waxy starch is one or more selected from the group consisting of tapioca starch, corn starch, potato starch and rice starch.

[0016] [4] A method for producing a starch decomposition product, wherein, in any one of [1] to [3] above, the mass ratio of waxy starch (solid mass ratio) to the total mass of waxy starch and non-waxy starch is at least 10 mass%.

[0017] [5] A method for producing a starch hydrolysate in any one of [1] to [4] above, wherein the number average molecular weight of the starch hydrolysate is 1,500 to 4,000 and the DP8 or higher of the sugar composition is 70% or higher. Effects of the invention

[0018] According to the method of the present invention, a starch hydrolysate with low DE and aging stability can be provided simply, inexpensively, and efficiently. Specific details for implementing the invention

[0019] “Starch hydrolysate” is also referred to as “syrup,” “dextrin,” “maltodextrin,” etc., and is obtained by hydrolyzing starch with acid and / or enzymes. The degree of hydrolysis is generally expressed as the “DE value” (dextrose equivalent). In the starch hydrolysate of the present invention, the DE value is 5 to 10, preferably 5 to 8, and more preferably 6 to 8. The DE value referred to here is an analytical value obtained by the Willstatter Schudel method, calculated by the formula “[(mass of direct reducing sugar (indicated as glucose)) / (mass of solid content)] × 100”.

[0020] In the method of the present invention, the “waxy starch” serving as a raw material is a starch having an amylopectin content of 90 mass% or more, preferably 95 mass% or more. This “waxy starch” may be a plant-derived starch containing algae obtained by standard breeding techniques, including genetic engineering techniques, in addition to natural starch found in nature, and representative sources thereof are cereals, tubers, roots, peas, legumes, and fruits. More specific examples of sources include waxy varieties of corn, peas, potatoes, sweet potatoes, bananas, barley, wheat, rice, sago, amaranth, tapioca, canna, and sorghum. Preferably, it is waxy tapioca, waxy corn, waxy potato, or glutinous rice, and among these, waxy tapioca is more preferred.

[0021] In the method of the present invention, the “non-waxy starch” serving as a raw material refers to a starch other than the above-mentioned waxy starch, and includes so-called high-amylose starch. Its amylopectin content is less than 90 mass%, preferably less than 85 mass%. This “non-waxy starch” may be any plant-derived starch, including algae obtained by standard breeding techniques including genetic engineering, in addition to natural starch found in nature; representative sources include cereals, tubers, roots, potatoes, legumes, and fruits. More specific examples of sources include corn, peas, potatoes, sweet potatoes, bananas, barley, wheat, rice, sago, amaranth, tapioca, canna, and sorghum, but are preferably tapioca, corn, potatoes, or rice, among which tapioca is more preferred.

[0022] The method of the present invention uses a mixed suspension of waxy starch and non-waxy starch. To prepare the mixed suspension, the method may include a process of mixing the waxy starch and non-waxy starch in advance before the hydrolysis process (raw material mixing process).

[0023] For a mixed suspension of waxy starch and non-waxy starch, the mixing ratio (solid mass ratio) is important, and the mass ratio of waxy starch to the total mass of waxy starch and non-waxy starch should be at least 10 mass%. Preferably, it should be 30 mass% or more, and more preferably 50 mass% or more. Above all, since waxy starch is expensive, considering the cost-effectiveness, it is desirable for the mass ratio of waxy starch to the total mass of waxy starch and non-waxy starch to remain in the range of 10 to 50 mass%.

[0024] The solvent for the mixed suspension of waxy starch and non-waxy starch is not particularly limited, but water can be used as an example.

[0025] The total mass fraction of solids of waxy starch and non-waxy starch in the mixed suspension provided for hydrolysis is preferably 15 to 40 mass%, and more preferably 20 to 40 mass%.

[0026] The method of the present invention requires undergoing a process of hydrolyzing a mixed suspension of the waxy starch and non-waxy starch mixed in a specific mass ratio (hydrolysis process), and may additionally include a purification process (purification process).

[0027] In the above hydrolysis process, hydrolysis is performed using an acid and / or α-amylase. When an acid is used, the type of acid used is not particularly limited, but examples include hydrochloric acid or oxalic acid. The amount of acid used can be appropriately adjusted depending on the type of acid, and for example, in the case of oxalic acid, it is preferable to be 0.1 to 0.6 mass% with respect to the solid mass of the raw starch (total of waxy starch and non-waxy starch), and more preferably 0.1 to 0.5 mass%.

[0028] The temperature in the above acid hydrolysis process is preferably 100°C to 140°C, more preferably 120°C to 140°C, the pH is preferably 1.0 to 2.0, more preferably 1.6 to 2.0, and the treatment time is preferably 5 minutes to 60 minutes, more preferably 10 minutes to 40 minutes. In addition, the raw starch concentration during treatment is preferably about 15 to 40 mass%. This acid hydrolysis process may also be performed using a heating device such as a heated pressurized steamer or a jet cooker. The treatment temperature and treatment time can be controlled while monitoring the progress of the reaction using thin-layer chromatography, HPLC, DE values, osmotic pressure, etc.

[0029] “α-amylase” is an endo-type enzyme that hydrolyzes α-1,4 glucosidic bonds of starch, examples of which include Crystase L1 (Amano Enzyme Co.) and Tamamyl 120L (Novozymes Japan). The amount of this α-amylase used is preferably 0.01 to 0.2 mass% with respect to the solid mass of the raw starch (total mass of waxy starch and non-waxy starch), and more preferably 0.02 to 0.18 mass%.

[0030] The temperature in the hydrolysis process by α-amylase is preferably 70°C to 100°C, more preferably 75°C to 90°C, and the pH is preferably 5.0 to 7.0, more preferably 5.5 to 6.5.

[0031] In addition, when treating with α-amylase, it is preferable that the concentration of raw starch (total of waxy starch and non-waxy starch) be approximately 15 to 40 mass%. At this time, the hydrolysis reaction by α-amylase can be controlled by setting the reaction treatment time to preferably 3 to 40 minutes, and more preferably 5 to 30 minutes. Alternatively, the reaction may be controlled by terminating it with a pressure treatment of approximately 0.2 MPa or an acid such as oxalic acid when the DE value or osmotic pressure (15 mass% aqueous solution) of the decomposed product reaches a predetermined range, for example, a DE value of 5 to 10 or an osmotic pressure of 50 to 110 mOSmol / kg. Furthermore, this hydrolysis process by α-amylase may utilize a heating device such as a heated pressurized steamer or a jet cooker.

[0032] As described above, the hydrolysis process can be carried out not only by acid or α-amylase, but also by a two-stage hydrolysis by acid and α-amylase. For example, acid hydrolysis under the above conditions can be performed first, and after adjusting the pH to 5.0 to 7.0 with oxalic acid or slaked lime, hydrolysis by α-amylase under the above conditions can be performed. Furthermore, acid hydrolysis can be performed after α-amylase hydrolysis, or additional α-amylase hydrolysis can be performed after α-amylase hydrolysis; however, the latter is preferable from the perspective of manufacturing efficiency.

[0033] In the case where additional α-amylase degradation is performed after α-amylase degradation, for example, α-amylase is added to raw starch at a concentration of about 15 to 40 mass%, in an amount of 0.01 to 0.2 mass%, more preferably 0.02 to 0.18 mass%, relative to the solid mass of the raw starch, and the first stage of α-amylase degradation is performed. The treatment time is preferably 3 to 40 minutes, more preferably 5 to 30 minutes. In the second stage of the α-amylase degradation process, α-amylase degradation can be performed by adding α-amylase in an amount of 0.01 to 0.2 mass%, more preferably 0.02 to 0.1 mass%, relative to the solid mass of the decomposition solution of the first stage. In addition, in the second stage of the α-amylase decomposition process, when the osmotic pressure of the decomposition product (15 mass% aqueous solution) reaches a predetermined range, for example, 50 to 110 mOSmol / kg, the reaction may be terminated by pressurizing treatment of about 0.2 MPa or by an acid such as oxalic acid.

[0034] When performing α-amylase decomposition (second stage) following α-amylase decomposition (first stage), the treatment temperature for either decomposition process is preferably 70°C to 100°C, more preferably 75°C to 90°C, and the pH is preferably 5.0 to 7.0, more preferably 5.5 to 6.5. In this decomposition process, heating devices such as heated pressurized steamers or jet cookers may be used from the perspective of manufacturing efficiency. It appears that by performing pressurized treatment, etc., following the α-amylase decomposition of the first stage, the shape of the starch chain changes, making it easier for the α-amylase of the second stage to act, thereby enabling uniform and efficient decomposition.

[0035] The reaction solution obtained through the above hydrolysis process can be concentrated into a liquid product by filtration with diatomaceous earth and desalination with an ion exchange resin, or powdered into a powder product by spray drying, etc. Additionally, the liquid of the starch hydrolysate after purification can be reduced (hydrogenated) as is to obtain a reduced starch hydrolysate.

[0036] The starch hydrolysate obtained by the method of the present invention has excellent retrogradation stability. The “retrogradation stability” referred to herein is evaluated using the turbidity after refrigerating a 15 mass% aqueous solution of the starch hydrolysate at 4°C for a certain period as an indicator, and the turbidity is a value obtained by multiplying the absorbance of the 15 mass% aqueous solution of the starch hydrolysate at 720 nm (1 cm cell) by 10. In addition, the corresponding turbidity on the 16th day of refrigeration is 10.0 or less, preferably 2.0 or less, and more preferably 1.6 or less.

[0037] The molecular weight referred to in the present invention is a number-average molecular weight and can be obtained from a molecular weight distribution obtained by high-speed liquid chromatography by gel filtration (Shimadzu Corporation). For example, it can be obtained from a molecular weight distribution obtained under the following analysis conditions:

[0038] [Column]: TSKgel G2500PWXL, G3000PWXL, G6000PWXL (Tosoh Corp.),

[0039] [Column Temperature]: 80℃

[0040] [Mobile phase]: Distilled water,

[0041] [Flow rate]: 0.5 ml / min,

[0042] [Detector]: Differential refractometer,

[0043] [Sample injection volume]: 100 µl of 1 mass% aqueous solution,

[0044] [Calibration Curve]: Pullulan standard (Showa Denko Co., Ltd.), maltotriose and glucose.

[0045] From the above molecular weight distribution, the number-average molecular weight Mn can be calculated by the following formula:

[0046] Mn = ΣHi / (Hi / Mi)[Hi: peak height, Mi: molecular weight].

[0047] The analysis of the sugar composition in the present invention is performed using the following method with high-speed liquid chromatography, and the composition is expressed as a simple area %:

[0048] [Column]: MCI GEL CK04SS (Mitsubishi Chemical Corporation)

[0049] [Column Temperature]: 80℃

[0050] [Mobile phase]: Distilled water,

[0051] [Flow rate]: 0.3 ml / min,

[0052] [Detector]: Differential refractometer,

[0053] [Sample injection volume]: 10 µl of 5 mass% solution.

[0054] The starch hydrolysate obtained by the method of the present invention has a number average molecular weight of 1,500 to 4,000, preferably 2,000 to 4,000, more preferably 2,000 to 3,000, and the sugar composition has a ratio of DP8 or higher of 70% or more, preferably 80% to 93%, more preferably 80% to 88%, and a DE value of 5 to 10, preferably 5 to 8, more preferably 6 to 8. This DE value is a relatively low value for a starch hydrolysate. The starch hydrolysate obtained by the method of the present invention has high retrogradation stability despite having a low DE value.

[0055] The starch hydrolysate obtained by the method of the present invention can be preferably used in food products. The types of food products are not particularly limited, but they can be particularly preferably used in liquid or fluid food products where transparency or softness is important. Examples include soft drinks such as coffee, black tea, and juice; beverages such as alcoholic drinks; milk-containing foods such as ice cream, milk pudding, custard cream, yogurt, and mousse; dessert products such as jelly; broths and seasonings; condiments such as sushi vinegar, dressings, ketchup, and sauces; curry, stew, thickened liquid food, and enteral nutrition products. They can be particularly advantageously used in beverages, dessert products such as mousse, broths and seasonings, sauces, dressings, etc.

[0056] In these foods, the content of the starch hydrolysate obtained by the method of the present invention is preferably 1 to 30 mass%, more preferably 2 to 15 mass%, and even more preferably 2 to 11 mass%, and when the said content is satisfied, a food product that does not impair transparency and has suppressed turbidity caused by aging can be obtained.

[0057] The present invention will be described in detail below by presenting examples, but the present invention is not limited to these examples.

[0058] [Example]

[0059] <Mixing of raw starch>

[0060] A mixed raw material was prepared by combining waxy tapioca starch and tapioca starch in the mass ratio shown in Table 1.

[0061] Starch mixture 1 Starch mixture 2 Starch mixture 3 Starch mixture 4 Waxy tapioca starch 10 30 100 0 tapioca starch 90 70 0 100

[0062] Hydrolysis

[0063] Each mixed raw material in Table 1 was suspended in water to prepare a 21 mass% starch slurry, and after adjusting the pH to approximately 6.0 using slaked lime and oxalic acid, α-amylase (Crystase L1, Amanoenzyme Co.) was added to achieve a solid content of 0.14 mass% relative to the raw materials. This enzyme-starch water suspension was placed in a heated pressurized steamer maintained at 83°C to perform the enzymatic reaction for 29 minutes, and the enzyme was inactivated by pressure treatment at 0.2 MPa to obtain a hydrolysis solution. The DE value of this hydrolysis solution was 4.4 to 4.8. Subsequently, the pH of this hydrolysis solution was adjusted to approximately 6.0 using slaked lime and oxalic acid, and the aforementioned α-amylase was added again to achieve a solid content of 0.04 mass% relative to the raw materials, and the reaction was carried out at 83°C. After that, when the osmotic pressure (15 mass% aqueous solution) reached 62 to 66 mOSmol / kg, the enzyme was inactivated by lowering the pH to 3.5 or lower with oxalic acid to obtain a two-stage decomposition solution with a DE value of 6.4 to 6.7.

[0064] Purification and Concentration

[0065] The obtained two-stage decomposition solution was purified by filtration with activated carbon and diatomite and desalination with an ion exchange resin, and then concentrated to 30 mass% to obtain starch decomposition product prototypes 1 to 4 (hereinafter referred to as “Prototype No. 1 to No. 4”) corresponding to starch mixtures 1 to 4, respectively.

[0066] Mixture of Starch Decomposition Products

[0067] Prototype No. 3 (degradable product of waxy tapioca starch) and Prototype No. 4 (degradable product of tapioca starch) were mixed in the mass ratio of Table 2 to prepare each aqueous solution of 30 mass%.

[0068] Starch hydrolysate mixture 1 Starch hydrolysate mixture 2 Starch hydrolysate mixture 3 Starch hydrolysate mixture 4 Starch hydrolysate prototype No. 3 10 30 40 50 Starch hydrolysate prototype No. 4 90 70 60 50

[0069] (pH, conductivity)

[0070] The pH of the 30 mass% aqueous solution was measured using a pH meter (D-51, Horiba Corporation). The conductivity of the 30 mass% aqueous solution was measured using an electrical conductivity meter (ES-71, Horiba Corporation).

[0071] (Coloration, Turbidity)

[0072] The color intensity and turbidity of each starch hydrolysate were measured by placing a 30 mass% aqueous solution into a 1 cm plastic cell. The color intensity was determined using a value obtained by multiplying the difference between the absorbance at 420 nm and 720 nm by 10 (spectrophotometer U-2900, Hitachi High-Technology Co., Ltd.), and the turbidity was determined using a value obtained by multiplying the absorbance at a wavelength of 720 nm by 10.

[0073] (DE value)

[0074] The DE values ​​of the decomposition products at the manufacturing process stage or the finally obtained starch decomposition products were measured by Willstatter Schudel (“Industrial Analytical Methods Related to Starch Sugars”, published by the Food Chemistry Newspaper (published November 1, 1991)).

[0075] (Osmotic pressure)

[0076] The osmotic pressure of each starch hydrolysate was measured using an osmometer (ModelOsmometer3250, ADVANCED INSTRUMENTS) for a 10 mass% aqueous solution.

[0077] (viscosity)

[0078] The viscosity of each starch hydrolysate was measured for 30 seconds using a clay system (BM type Toki Industry Co., Ltd.) and rotor number 1, with a 30 mass% aqueous solution maintained at 30°C and set to 60 revolutions / min.

[0079] (Number average molecular weight)

[0080] The number average molecular weight of each starch hydrolysate was determined from the molecular weight distribution obtained by high-speed liquid chromatography by gel filtration. The analysis conditions are shown in Table 3, and the formula for calculating the number average molecular weight Mn is shown in Equation 1.

[0081] [column] TSKgel G2500PWXL, G3000PWXL, G6000PWXL (Manufactured by Tosoh Co., Ltd.) [Column Temperature] 80℃ [Moving Image] distilled water [Flow velocity] 0.5㎖ / min [Detector] refractive index meter [Sample Injection Volume] 100 µl of 1 mass% aqueous solution [Calibration Curve] Pullulan Standard (Showa Denko Co., Ltd.), Maltotriose and Glucose

[0082] [Mathematical Formula 1]

[0083] Mn = ΣHi / (Hi / Mi) [Hi: peak height, Mi: molecular weight]

[0084] (Party composition)

[0085] The sugar composition of the starch hydrolysate was determined as the sugar composition % (mass%) by calculating the simple area % (ratio when the total peak area (corresponding to the total amount of sugar in the sample) is set to 100%) from the chromatogram obtained by high-speed liquid chromatography under the conditions shown in Table 4.

[0086] [column] 80℃ [Column Temperature] distilled water [Moving Image] MCI GEL CK04SS (Mitsubishi Chemical Corporation) [Flow velocity] 0.3㎖ / min [Detector] refractive index meter [Sample Injection Volume] 10 µl of 5 mass% solution

[0087] The results of the above analysis are shown in Table 5.

[0088] Prototype No. (Starch decomposition product prototype by raw material mixing) Mixture No. (Mixture of starch hydrolysates) 1 2 3 4 1 2 3 4 pH 4.15 4.04 4.16 4.23 4.22 4.21 4.20 4.20 Conductivity (μs / cm) 11.9 15.4 16.8 10.3 11.0 12.3 12.9 13.6 Coloration 0.10 0.13 0.31 0.12 0.15 0.19 0.21 0.23 Turbidity 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 DE (WS method) 6.29 6.12 6.21 6.18 6.17 6.14 6.16 6.18 Permeation pressure (mOsm / kg) 37 35 34 35 36 35 35 35 Viscosity (cp) 19.9 20.8 19.1 20.8 21.2 20.7 20.6 20.2 Number average molecular weight 2,687 2,854 2,866 2,759 2,773 2,798 2,807 2,823 Party formation DP8+ 85.5 86.4 86.2 86.1 86.1 86.2 86.2 86.2 DP7 3.9 3.7 3.8 3.7 3.7 3.8 3.8 3.8 DP6 3.2 3.1 3.2 3.1 3.1 3.1 3.2 3.2 DP5 1.7 1.5 1.5 1.7 1.6 1.6 1.6 1.6 DP4 1.9 1.8 1.7 1.9 1.8 1.8 1.8 1.8 DP3 2.3 2.1 2.1 2.2 2.1 2.1 2.1 2.1 DP2 1.3 1.1 1.2 1.2 1.2 1.2 1.2 1.2 DP1 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2

[0089] (Aging stability)

[0090] A 15 mass% aqueous solution of each starch hydrolysate was placed in a glass vial and refrigerated at 4°C for 0, 2, 4, 6, 8, 12, and 16 days, and turbidity was measured over time. The results are shown in Table 6 below.

[0091] Days Prototype No. (Starch decomposition product prototype by raw material mixing) Mixture No. (Mixture of starch hydrolysates) １ ２ ３ ４ １ ２ ３ ４ Day 0 Day 2 Day 4 Day 6 Day 8 Day 12 Day 16 0.00 0.00 0.01 0.00 0.00 0.00 0.00 0.00 0.11 0.01 0.01 0.24 0.16 0.05 0.02 0.01 0.44 0.08 0.01 0.90 0.54 0.18 0.11 0.05 1.10 0.19 0.01 2.39 1.32 0.40 0.23 0.12 2.20 0.35 0.01 4.64 2.67 0.77 0.41 0.33 5.47 0.78 0.01 >10 6.79 1.95 1.03 0.51 9.17 1.56 0.02 >10 >10 3.81 1.93 0.91

[0092] When comparing Prototype No. 1 and Mixed Product No. 1 (both identical at 10 mass%), or Prototype No. 2 and Mixed Product No. 2 (both identical at 30 mass%), which have the same ratio of waxy starch to non-waxy starch, it was found that the Prototype had superior retrogradation stability compared to the Mixed Product. In addition, Prototype No. 2 (mixing ratio of waxy starch at 30 mass%) had superior retrogradation stability compared to Mixed Product No. 3 (mixing ratio of waxy starch at 40 mass%), and it was found that a starch degradation product with excellent retrogradation stability could be efficiently obtained by mixing a small amount of waxy starch at the raw material stage.

[0093] In order to efficiently improve retrogradation stability from the above, at the raw material stage, waxy starch and non-waxy starch are mixed in a mass ratio (solid mass ratio) such that the waxy starch is at least 10 mass% relative to the total mass of the waxy starch and non-waxy starch, and this is hydrolyzed with an acid and / or α-amylase. The starch hydrolysate obtained by this method has a DE value of 5 to 10, a number average molecular weight of 1,500 to 4,000, and a ratio of DP8 or higher in the sugar composition of 70% or more, and has improved retrogradation stability.

Claims

Claim 1 A method for producing a starch hydrolysate comprising a process of hydrolyzing a mixed suspension of waxy starch and non-waxy starch by applying one or more of an acid or α-amylase, wherein the mass ratio of waxy starch to the total mass of waxy starch and non-waxy starch (mass ratio of solids) is at least 10 mass%. Claim 2 A method for producing a starch hydrolysate according to claim 1, wherein the waxy starch is one or more selected from the group consisting of waxy tapioca starch, waxy corn starch, waxy potato starch, and glutinous rice starch. Claim 3 A method for producing a starch hydrolysate according to claim 1, wherein the non-waxy starch is one or more selected from the group consisting of tapioca starch, corn starch, potato starch and rice starch. Claim 4 A method for producing a starch hydrolysate according to paragraph 2, wherein the non-waxy starch is one or more selected from the group consisting of tapioca starch, corn starch, potato starch and rice starch. Claim 5 delete Claim 6 delete Claim 7 A method for producing a starch hydrolysate according to any one of claims 1 to 4, wherein the number average molecular weight of the starch hydrolysate is 1,500 to 4,000 and the DP8 or higher of the sugar composition is 70% or higher.