A fresh-eating sweet potato saccharification process

Abstract

The invention belongs to the field of sweet potato saccharification technology, and is particularly related to a sweet potato saccharification process for fresh-eating type, comprising: washing, peeling, and dicing fresh-eating type sweet potato raw materials to obtain sweet potato pieces; soaking the sweet potato pieces in a saccharification test solution, wherein the formula of the saccharification test solution is as follows: 50-80 mg of alpha-amylase and 1 L of deionized water; the soaking process is as follows: adjusting pH to 5.5-6, soaking for 0.5h-1h, then adjusting pH to 7.2-7.5, and soaking for 15min-20min; taking out the sweet potato pieces, washing, and completing saccharification. The present invention saves equipment energy, can quickly saccharify fresh-eating type sweet potatoes without high-temperature saccharification treatment, has a good saccharification effect, and the sweet potatoes after saccharification can be eaten raw.

Description

Technical Field

[0001] The invention belongs to the technical field of sweet potato saccharification, and particularly relates to a fresh-eating sweet potato saccharification process. Background Art

[0002] Sweet potato (Ipomoea batatas Lam) is a herbaceous plant belonging to the genus Ipomoea of ​​the family Convolvulaceae. It is also known as yam, red taro, sweet potato, sweet potato, sweet potato, sweet potato, etc. Natural sweet potato saccharification belongs to enzymatic saccharification. The process of converting sweet potato into sugar under the action of its own amylase is called sweet potato saccharification. As a result, the sweet potato will become sweeter and more sticky, and the taste will be improved. Since the optimal pH of some enzymes is acidic, there is also a saccharification process of acid-enzyme combination in some saccharification processes.

[0003] Studies have shown that the hardness and sweetness of sweet potatoes are significantly related to their starch content, so starch is usually saccharified by exogenous addition of amylase to increase the sweetness of sweet potatoes. For example, sweet potatoes are cooked by steaming and baking to increase their sweetness. Another example is to use thermostable α-amylase to saccharify sweet potato pulp after beating the sweet potatoes to increase the sweetness of the sweet potato pulp. Another example is to use thermostable α-amylase to saccharify sweet potato puree. (Reference 1: Ye Xiafang, Hu Qiongzhi, Qiu Tianyue, et al. Effects of different varieties and processing methods on the saccharification characteristics of sweet potatoes [J]. Henan Agricultural Sciences, 2019, 48(7):9. DOI:10.15933 / j.cnki.1004-3268.2019.07.021; Reference 2: Li Zhenghao, Luo Cangxue. Research on the process of liquefaction and saccharification in the processing of sweet potato concentrated juice [J]. Food Industry Science and Technology, 2010(2):3. DOI:CNKI:SUN:SPKJ.0.2010-02-050; Reference 3: CN101347219B).

[0004] Most of the above processes are saccharification after ripening. The sweet potato ripening process can not only increase the sweetness, but also has a sterilizing effect, but ripening requires heat consumption, such as steaming in a steamer or baking in an oven. For fresh-eating sweet potato varieties, they can be eaten raw or cooked. For the raw eating method, the ripening process cannot be used, but if it is not ripened, the saccharification effect of the thermostable α-amylase is poor. Summary of the invention

[0005] In order to meet the saccharification requirements of raw sweet potatoes and to save equipment energy without high-temperature cooking treatment, the present invention provides a fresh-type sweet potato saccharification process.

[0006] The technical solution of the present invention is as follows:

[0007] A fresh-eating sweet potato saccharification process comprises:

[0008] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato chunks; after the sweet potato is cut into pieces, the volume becomes smaller, and the surface area of ​​all the sweet potato chunks added together is greater than the surface area of ​​the original whole sweet potato, so the contact area between the sweet potato chunks and the saccharification test solution is large.

[0009] Second, soak the sweet potato pieces in saccharification solution;

[0010] The soaking process is as follows: adjust the pH to 5.5-6, soak for 0.5h-1h, then adjust the pH to 7.2-7.5, soak for 15min-20min;

[0011] After the above soaking process is repeated 2-3 times, the third step is performed;

[0012] The formula of the saccharification test solution is as follows: 50-80 mg of α-amylase and dilute to 1 L with deionized water. The saccharification test solution of the present invention uses only α-amylase, has a simple formula, and does not need to be compounded with other enzymes; although the formula of the saccharification test solution of the present invention is simple, it still has a good saccharification effect when combined with the saccharification process of the present invention.

[0013] When α-amylase hydrolyzes starch long-chain molecules into short-chain molecules, it cuts the α-1,4 glycosidic bonds inside the starch macromolecules in an irregular manner to generate dextrins, oligosaccharides, etc. from starch. Because the C, carbon atoms in the terminal glucose residues of the product are in α-configuration, it is called α-amylase. Previous studies have confirmed that α-amylase has higher enzymatic activity under acidic conditions and the optimal pH is acidic. Therefore, most of the existing technologies carry out saccharification reactions under acidic conditions. However, in fact, when α-amylase is between pH 5.5-8.0, the structure is relatively stable and active. Although alkaline conditions are not the optimal pH, α-amylase can also play a saccharification role under alkaline conditions. The present invention gives full play to the structural characteristics of α-amylase, adopts an acid-base alternating environment, plays a major saccharification role under acidic conditions of pH 5.5-6, and plays a secondary saccharification role under weakly alkaline conditions of pH 7.2-7.5; in addition, under acidic conditions, H in the system + There are many ions, and under weak alkaline conditions, there is OH in the system - There are many ions, and the two have different charges and polarities. By changing the charge and polarity, the starch molecule breakage is accelerated and the saccharification reaction is accelerated. Therefore, the method of the present invention does not require high-temperature cooking treatment and still has a good saccharification effect, so that the sweet potato can be eaten fresh.

[0014] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0015] Furthermore, the optimal soaking process is to adjust the pH to 5.5, soak for 1 hour, and then adjust the pH to 7.2 and soak for 15 minutes.

[0016] Furthermore, in the above-mentioned fresh-eating sweet potato saccharification process, the pH is adjusted with 1 mol / L sodium hydroxide solution or 1 mol / L hydrochloric acid, which are common pH regulators, are simple to operate, inexpensive, and do not have much impact on the quality of the sweet potato.

[0017] Furthermore, in the above-mentioned fresh-type sweet potato saccharification process, the enzyme activity of α-amylase is ≥10000U / g, CAS: 9000-85-5, the α-amylase is extracted from Bacillus subtilis, and is a light yellow powder. The α-amylase product is purchased from Beijing Huamaike Biotechnology Co., Ltd.

[0018] Furthermore, the optimal saccharification test solution formula is as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0019] Furthermore, in the above-mentioned fresh-eating sweet potato saccharification process, the soaking temperature is 35-40°C. Although this temperature is a little higher than the conventional room temperature of 25°C, it is room temperature and does not affect the quality and taste of the sweet potato. At a soaking temperature of 35-40°C, the saccharification efficiency is the highest.

[0020] Furthermore, in the above-mentioned fresh-eating sweet potato saccharification process, the material-liquid ratio of the sweet potato pieces to the saccharification test solution is 1 kg: 6-10 L. Pay attention to the selection of the soaking container to ensure that the sweet potato pieces are below the liquid level of the saccharification test solution during soaking.

[0021] Furthermore, in the above-mentioned fresh-eating sweet potato saccharification process, the size of the sweet potato pieces is 1-3cm×1-3cm×1-3cm, or the weight of the sweet potato pieces is 30g-50g.

[0022] Furthermore, the above-mentioned fresh-eating sweet potato saccharification process adopts a stirring and soaking method, and stirring helps the materials to be evenly mixed and fully contacted. More preferably, the stirring speed is 20-50r / min, and slow stirring is preferred to prevent high-speed stirring from causing damage to the sweet potato pieces.

[0023] Preferably, the above-mentioned fresh-eating sweet potato saccharification process is suitable for varieties of Yanshu 25, Jishu 26, Pushu 32, Sushu 8, Longshu 9, Jishu 35, Qining 21, Qining 18, Taizishu 1, Xushu 34, Zheshu 259, Guangshu 87, Xushu 23, Sushu 16, Zheshu 6025, Zheshu 70, Zheshu 132, Yanshu 5, Yizi 138, Jishu 4 or Qinshu 8. These varieties are all common fresh-eating sweet potato varieties on the market.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] 1. The saccharification test solution of the present invention uses only α-amylase, has a simple formula, and does not need to be compounded with other enzymes. After the saccharification test solution is combined with the saccharification process of the present invention, it still has a good saccharification effect.

[0026] 2. The present invention gives full play to the structural characteristics of α-amylase, adopts an acid-base alternating environment, plays a major saccharification role under acidic conditions of pH 5.5-6, and plays a secondary saccharification role under weakly alkaline conditions of pH 7.2-7.5; in addition, under acidic conditions, H + There are many ions, and under weak alkaline conditions, there is OH in the system - There are many ions, and the two have different charges and polarities. The saccharification reaction is accelerated by changing the charge and polarity. Therefore, the method of the present invention does not require high-temperature ripening treatment, is energy-saving, and still has a good saccharification effect, and the sweet potato can be eaten fresh.

[0027] 3. The research results of the present invention show that the saccharification efficiency is highest at a soaking temperature of 35-40°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a process flow chart of the fresh-eating sweet potato saccharification process of Example 1.

[0029] Figure 2 This is the test result of the first group of experiments on the content of soluble sugar and reducing sugar.

[0030] Figure 3 These are the test results of the second group of experiments on the content of soluble sugar and reducing sugar. DETAILED DESCRIPTION

[0031] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments and drawings.

[0032] In the description of the present invention, unless otherwise specified, all reagents used are commercially available and all methods used are conventional techniques in the art.

[0033] The enzyme activity of α-amylase is ≥10000U / g, CAS: 9000-85-5, α-amylase is extracted from Bacillus subtilis, light yellow powder, and the α-amylase product is purchased from Beijing Huamaike Biotechnology Co., Ltd., item number 180855.

[0034] Sugar detection method:

[0035] (1) Soluble sugar content: determined by anthrone colorimetric method.

[0036] (2) Reducing sugar content: Determined by DNS colorimetric method.

[0037] The above-mentioned sugar detection methods all adopt existing technologies. For example, the present invention adopts the method described in "Ye Xiafang, Hu Qiongzhi, Qiu Tianyue, et al. Effects of different varieties and processing methods on sweet potato saccharification characteristics [J]. Henan Agricultural Science, 2019, 48(7): 9. DOI: 10.15933 / j.cnki.1004-3268.2019.07.021". The test methods and sample processing methods of each embodiment and experiment are the same, eliminating the influence of the test method on the test results.

[0038] Data processing: Three parallel tests were performed for each test and the average value was taken.

[0039] In order to illustrate the process and effect of the present invention, we carried out the following experiments.

[0040] The first group of experiments studied the effects of different saccharification test solution formulas on saccharification results. The specific methods and results are as follows:

[0041] Example 1

[0042] A fresh-eating sweet potato saccharification process, see Figure 1 , including the following steps:

[0043] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0044] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 50 mg of α-amylase and dilute to 1 L with deionized water.

[0045] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0046] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0047] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0048] Example 2

[0049] A fresh-eating sweet potato saccharification process comprises the following steps:

[0050] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0051] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 60 mg of α-amylase and dilute to 1 L with deionized water.

[0052] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0053] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0054] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0055] Example 3

[0056] A fresh-eating sweet potato saccharification process comprises the following steps:

[0057] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0058] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0059] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0060] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0061] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0062] Example 4

[0063] A fresh-eating sweet potato saccharification process comprises the following steps:

[0064] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0065] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 80 mg of α-amylase and dilute to 1 L with deionized water.

[0066] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0067] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0068] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0069] Comparative Example 1

[0070] A fresh-eating sweet potato saccharification process comprises the following steps:

[0071] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0072] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 50 mg of complex enzyme and dilute to 1 L with deionized water. In the complex enzyme, the mass ratio of α-amylase, β-amylase, isoamylase, and cellulase was 1:1:0.8:0.6.

[0073] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0074] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0075] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0076] The results of the first group of experiments are shown in Table 1. The experimental sweet potato variety is Yanshu 25. In Table 1, blank group 1 is fresh sweet potato pieces without any enzymatic hydrolysis or cooking process treatment. The saccharification efficiency is the percentage of the total amount of soluble sugar + reducing sugar increased compared to the original sweet potato after saccharification process treatment. In order to more intuitively express the difference in the effects of each experimental group, the Figure 2 , Figure 2 The results of the first group of experiments on the content of soluble sugar and reducing sugar are shown in Table 1. Figure 2 The results showed that the optimal saccharification solution formula was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0077] Table 1 Results of the first set of experiments

[0078]

[0079] Note: “-” means the data is not tested.

[0080] The second group of experiments studied the effects of different soaking processes on saccharification results. The specific methods and results are as follows:

[0081] Example 5

[0082] A fresh-eating sweet potato saccharification process comprises the following steps:

[0083] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0084] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0085] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0086] The soaking process is as follows: adjust the pH to 6, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0087] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0088] Example 6

[0089] A fresh-eating sweet potato saccharification process comprises the following steps:

[0090] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0091] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0092] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0093] The soaking process is as follows: adjust the pH to 5.5, soak for 0.5 h, then adjust the pH to 7.2, soak for 15 min;

[0094] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0095] Example 7

[0096] A fresh-eating sweet potato saccharification process comprises the following steps:

[0097] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0098] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0099] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0100] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.5, soak for 15 minutes;

[0101] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0102] Example 8

[0103] A fresh-eating sweet potato saccharification process comprises the following steps:

[0104] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0105] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0106] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0107] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 20 minutes;

[0108] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0109] Example 9

[0110] A fresh-eating sweet potato saccharification process comprises the following steps:

[0111] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0112] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0113] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0114] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0115] The soaking process is carried out continuously for 2 times.

[0116] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0117] Example 10

[0118] A fresh-eating sweet potato saccharification process comprises the following steps:

[0119] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0120] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0121] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0122] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0123] The soaking process was performed continuously for 3 times.

[0124] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0125] Embodiment 11

[0126] A fresh-eating sweet potato saccharification process comprises the following steps:

[0127] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0128] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0129] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:6L.

[0130] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0131] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0132] Example 12

[0133] A fresh-eating sweet potato saccharification process comprises the following steps:

[0134] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0135] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0136] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:10L.

[0137] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0138] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0139] Example 13

[0140] A fresh-eating sweet potato saccharification process comprises the following steps:

[0141] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0142] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0143] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0144] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes; adopt the stirring soaking method, and the stirring speed is 20r / min.

[0145] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0146] Embodiment 14

[0147] A fresh-eating sweet potato saccharification process comprises the following steps:

[0148] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0149] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0150] The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:8L.

[0151] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes; adopt the stirring soaking method, and the stirring speed is 50r / min.

[0152] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0153] Examples 1-14, Blank 1 and Control 1 were all immersed at room temperature of 25°C.

[0154] Embodiment 15

[0155] A fresh-eating sweet potato saccharification process comprises the following steps:

[0156] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0157] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0158] The material-liquid ratio of sweet potato pieces to saccharification test solution is 1 kg: 8 L. The soaking temperature is 35°C.

[0159] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0160] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0161] Example 16

[0162] A fresh-eating sweet potato saccharification process comprises the following steps:

[0163] First, the fresh sweet potato raw material is washed, peeled, and cut into pieces to obtain sweet potato pieces, and the weight of the sweet potato pieces is 30 g.

[0164] Second, the sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase and dilute to 1 L with deionized water.

[0165] The material-liquid ratio of sweet potato pieces to saccharification test solution is 1 kg: 8 L. The soaking temperature is 40°C.

[0166] The soaking process is as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, soak for 15 minutes;

[0167] Third, take out the sweet potato pieces, wash them, and complete the saccharification.

[0168] The results of the second group of experiments are shown in Table 2. The experimental sweet potato variety is Yanshu 25. In Table 2, blank group 1 is fresh sweet potato pieces without any enzymatic hydrolysis or cooking process treatment. The saccharification efficiency is the percentage of the total amount of soluble sugar + reducing sugar increased compared to the original sweet potato after saccharification process treatment. Figure 3 The results of the second group of experiments are the test results of the content of soluble sugar and reducing sugar. The results show that the saccharification efficiency of different saccharification processes is also different, but all have high saccharification efficiency.

[0169] Table 2 Results of the second group of experiments

[0170]

[0171] Note: “-” means the data is not tested.

[0172] It should be noted that when the present invention involves a numerical range, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as those in the embodiments, in order to avoid redundancy, the present invention describes a preferred embodiment. Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the attached claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0173] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A fresh-eating sweet potato saccharification process, characterized in that: include Washing, peeling and cutting fresh sweet potato raw materials into pieces to obtain sweet potato pieces; the size of the sweet potato pieces is 1-3 cm×1-3 cm×1-3 cm, or the weight of the sweet potato pieces is 30 g-50 g; The sweet potato pieces were soaked in a saccharification test solution, the formula of which was as follows: 70 mg of α-amylase, dilute to 1 L with deionized water, and the activity of α-amylase was ≥ 10000 U / g; The soaking process is as follows: adjust the pH to 5.5-6, soak for 0.5h-1h, then adjust the pH to 7.2-7.5, soak for 15min-20min; adjust the pH with 1mol / L sodium hydroxide solution or 1mol / L hydrochloric acid; soak at 35-40℃; Take out the sweet potato pieces, wash them, and complete the saccharification.

2. The fresh-eating sweet potato saccharification process according to claim 1, characterized in that: The soaking process was as follows: adjust the pH to 5.5, soak for 1 hour, then adjust the pH to 7.2, and soak for 15 minutes.

3. The fresh-eating sweet potato saccharification process according to claim 1, characterized in that: The material-liquid ratio of sweet potato chunks to saccharification test solution is 1kg:6-10L.

4. The fresh-eating sweet potato saccharification process according to claim 1, characterized in that: The stirring and immersion method is adopted, and the stirring speed is 20-50r / min.

5. The fresh-eating sweet potato saccharification process according to any one of claims 1 to 4, characterized in that: The soaking process was repeated 2-3 times.

6. The fresh-eating sweet potato saccharification process according to claim 1, characterized in that: The process is used for increasing the soluble sugar content and reducing sugar content in sweet potatoes.

7. The fresh-eating sweet potato saccharification process according to claim 1, characterized in that: The varieties suitable for the fresh-eating sweet potato saccharification process are Yanshu 25, Jishu 26, Pushu 32, Sushu 8, Longshu 9, Jishu 35, Qining 21, Qining 18, Taizishu 1, Xushu 34, Zheshu 259, Guangshu 87, Xushu 23, Sushu 16, Zheshu 6025, Zheshu 70, Zheshu 132, Yanshu 5, Yizi 138, Jishu 4 or Qinshu 8.

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