Preparation method of sweet potato beverage based on utilization of sweet potato starch processing wastewater

Abstract

The invention relates to the technical field of sweet potato beverages, and discloses a sweet potato beverage preparation method based on sweet potato starch processing wastewater utilization, and the method mainly comprises the following steps: step 1, liquid taking: taking supernatant which is precipitated for 0.5-2 hours in a sweet potato starch production process; step 2, saccharifying: putting the supernatant into a saccharifying container; in the preparation process, the sterilized precipitate supernatant is saccharified and decomposed to form maltose and glucose, so that the sweet effect is achieved, and a large number of nutrient substances of sweet potatoes are dissolved in the liquid, so that the produced beverage is sweet in taste and rich in nutrition, is an excellent green natural health-care beverage, and has a good market prospect. Meanwhile, the problem that a large amount of wastewater generated by sweet potato starch processing pollutes the environment is also solved.

Description

Technical Field

[0001] The invention relates to the technical field of sweet potato beverages, and in particular to a method for preparing a sweet potato beverage based on the utilization of sweet potato starch processing wastewater. Background Art

[0002] Starch is the main component of human food and also an important industrial raw material. At present, starch is mainly produced by crops through photosynthesis, which converts solar energy, carbon dioxide and water. In the process of extracting starch, for example, sweet potatoes need to be washed first, then crushed, and the crushed products are washed with water during the crushing process, so that the water drives the white slurry to gather in the sedimentation tank for precipitation. The crushed powder residue is placed in one place to achieve residue wet separation, and the separated starch with water is precipitated. After precipitation, the lower solid is starch, and the starch can be collected after the upper liquid is discharged.

[0003] Two types of waste are generated in the process of starch production. One is the powder residue, which can be used for feed preparation later, and the other is the upper liquid after starch precipitation. There is no good way to treat the waste liquid. Large-scale discharge will cause environmental pollution. At the same time, a lot of odor will be generated due to the fermentation of the waste liquid.

[0005] Chinese patent application No. 200810044849.3 discloses a "processing method for a sweet potato beverage". The patent application adopts "cleaning, crushing, grinding, sterilizing and canning fresh sweet potatoes to obtain a sweet potato beverage product". The patent application has the following defects and shortcomings: (1) The sweet potato beverage product is actually raw sweet potato juice, which is no different from starch juice; (2) During the production process of the product, sweeteners, acidulants, flavors, etc. need to be added to enhance the flavor, which increases the production cost and cannot be green and natural.

[0006] The large amount of wastewater discharged during the existing sweet potato starch production process will pollute the environment. To this end, we propose a method for preparing sweet potato beverage based on the utilization of sweet potato starch processing wastewater. Summary of the invention

[0007] The main purpose of the present invention is to provide a method for preparing a waste sweet potato beverage obtained by a saccharification process using waste water generated by sweet potato starch processing as a raw material, which can effectively solve the problem of large-scale discharge of waste water in the production process of sweet potato starch in the background technology that pollutes the environment.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] The method for preparing a sweet potato beverage based on the utilization of sweet potato starch processing wastewater mainly comprises the following steps:

[0010] Step 1: Take liquid: take the upper liquid that has been precipitated for 0.5-2h during the production of sweet potato starch;

[0011] Step 2: Saccharification: Place the upper liquid in a saccharification container, add α-amylase to decompose the long-chain starch into low-molecular-weight dextrin, saccharify at 72-75°C for 0.5-1h, pH value is 5.6-5.8, then add β-amylase to decompose from the end of the starch chain to form maltose and glucose, saccharify at 60-65°C for 1-2h, pH value is 5.4-5.5;

[0012] Step 3: Sterilization: The upper layer liquid after saccharification in step 2 is pasteurized at 90°C to 100°C for 10-20 minutes. The resulting product is a sweet potato beverage, which can be filled later.

[0013] Furthermore, the starch content in the upper layer liquid after precipitation for 0.5-2h in step 1 is 10-20%, and no filtration is required when taking the liquid. There is a trace amount of powder residue inside, which increases the cellulose content in the liquid. If the precipitation time of the upper layer liquid exceeds 2h, it will ferment and produce sour taste.

[0014] Furthermore, in step 2, α-amylase can decompose the long chain of amylose or amylopectin into short-chain dextrins composed of 7 to 12 glucose units, and then β-amylase cuts off two glucose units at a time from the end of the short chain to form maltose; the action time of β-amylase is longer than that of α-amylase.

[0015] Furthermore, the sterilization method in step 3 may also be microwave sterilization for 2-30 minutes.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] After testing the waste liquid, it was found that it contains a large amount of carbohydrates and various trace nutrients. Therefore, by processing the starch upper layer liquid at different sedimentation time periods, sweet potato beverages can be produced, which can reduce environmental pollution while turning waste into treasure.

[0018] During the preparation process of the present invention, the sterilized precipitated upper liquid is subjected to saccharification treatment to decompose into maltose and glucose, so as to achieve a sweet taste effect without adding any sweeteners, acidulants, flavors, etc. to enhance the taste, thereby reducing costs, being more green and natural, and achieving no additives to a greater extent, thereby satisfying people's drinking needs.

[0019] The invention has simple process, extremely low raw material cost, rich nutritional value and is easy for human body to absorb. The product prepared by the invention retains the dietary fiber, vitamins, proteins, polysaccharides and other components in sweet potatoes, retains the nutritional components in sweet potatoes and the active components with improving human immunity to the maximum extent, and is an excellent green natural health beverage.

[0020] The preparation method of the present invention greatly saves the steps of juicing and filtering in the early stage, directly uses the precipitated upper waste liquid to turn waste into treasure, improves the product yield of sweet potatoes, and effectively avoids the pollution of the environment by the production waste liquid. DETAILED DESCRIPTION

[0021] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0022] Example 1

[0023] The method for preparing a sweet potato beverage based on the utilization of sweet potato starch processing wastewater mainly comprises the following steps:

[0024] Step 1: Take liquid: Take the upper liquid that has been precipitated for 0.5 hours during the production of sweet potato starch; the starch content in the upper liquid that has been precipitated for 0.5 hours is 20%. There is no need to filter the liquid when taking it. It contains trace amounts of powder residue, which increases the cellulose content in the liquid. If the upper liquid is precipitated for more than 2 hours, it will ferment and produce a sour taste.

[0025] Step 2: Saccharification: Place the upper liquid in a saccharification container, add α-amylase to decompose the long-chain starch into low-molecular-weight dextrins, saccharify at 72°C for 1 hour, and the pH value is 5.6-5.8. Then add β-amylase to decompose the starch chain from the end to form maltose and glucose, saccharify at 60°C for 2 hours, and the pH value is 5.4-5.5.

[0026] α-amylase can break down the long chain of amylose or amylopectin into short chain dextrins consisting of 7 to 12 glucose units, and then β-amylase cuts off two glucose units at a time from the end of the short chain to form maltose; the action time of β-amylase is longer than that of α-amylase;

[0027] Step 3: Sterilization: The upper layer liquid after saccharification in step 2 is pasteurized, that is, sterilized at a temperature of 90°C to 100°C for 20 minutes. The sterilization method can also be microwave sterilization for 30 minutes. The resulting product is a sweet potato beverage, which can be filled later.

[0028] Example 2

[0029] The method for preparing a sweet potato beverage based on the utilization of sweet potato starch processing wastewater mainly comprises the following steps:

[0030] Step 1: Take liquid: Take the upper liquid that has been precipitated for 1 hour during the production of sweet potato starch; the starch content in the upper liquid that has been precipitated for 1 hour is 15%. There is no need to filter the liquid when taking it. It contains trace amounts of powder residue, which increases the cellulose content in the liquid. If the upper liquid is precipitated for more than 2 hours, it will ferment and produce a sour taste.

[0031] Step 2: Saccharification: Place the upper liquid in a saccharification container, add α-amylase to decompose the long-chain starch into low-molecular-weight dextrins, saccharify at 74°C for 0.8h, pH value is 5.6-5.8, then add β-amylase to decompose from the end of the starch chain to form maltose and glucose, saccharify at 63°C for 1.5h, pH value is 5.4-5.5;

[0032] α-amylase can break down the long chain of amylose or amylopectin into short chain dextrins consisting of 7 to 12 glucose units, and then β-amylase cuts off two glucose units at a time from the end of the short chain to form maltose; the action time of β-amylase is longer than that of α-amylase;

[0033] Step 3: Sterilization: The upper layer liquid after saccharification in step 2 is pasteurized, that is, sterilized at a temperature of 90°C to 100°C for 15 minutes. The sterilization method can also be microwave sterilization for 15 minutes. The resulting product is a sweet potato beverage, which can be filled later.

[0034] Example 3

[0035] The method for preparing a sweet potato beverage based on the utilization of sweet potato starch processing wastewater mainly comprises the following steps:

[0036] Step 1: Take liquid: Take the upper liquid that has been precipitated for 2 hours during the production of sweet potato starch; the starch content in the upper liquid that has been precipitated for 2 hours is 10%. There is no need to filter the liquid when taking it. It contains trace amounts of powder residue, which increases the cellulose content in the liquid. If the upper liquid is precipitated for more than 2 hours, it will ferment and produce a sour taste.

[0037] Step 2: Saccharification: Place the upper liquid in a saccharification container, add α-amylase to decompose the long-chain starch into low-molecular-weight dextrins, saccharify at 75°C for 0.5h, pH value is 5.6-5.8, then add β-amylase to decompose from the end of the starch chain to form maltose and glucose, saccharify at 65°C for 1h, pH value is 5.4-5.5;

[0038] α-amylase can break down the long chain of amylose or amylopectin into short chain dextrins consisting of 7 to 12 glucose units, and then β-amylase cuts off two glucose units at a time from the end of the short chain to form maltose; the action time of β-amylase is longer than that of α-amylase;

[0039] Step 3: Sterilization: The upper layer liquid after saccharification in step 2 is pasteurized at 90°C to 100°C for 10 minutes. The sterilization method can also be microwave sterilization for 2 minutes. The resulting product is a sweet potato beverage, which can be filled later.

[0040] The sweet potato beverages prepared in the above Examples 1-3 were tested for sugar content respectively.

[0041] Sugar content test method: Take the three kinds of sweet potato beverages in Examples 1-3 above, use a high performance liquid chromatograph, with a differential refractive index detector and a specific chromatographic column (such as Nova Atom NH2, 4.6x250mm, 5μm), the mobile phase is 70% acetonitrile, the flow rate is 1.0ml / min, the column temperature is 40°C, the injection volume is 10μl, a standard curve is established, and the target content is calculated by the external standard method. The results are shown in Table 1:

[0042]

[0043] Table 1. Test of sugar content of sweet potato beverages prepared in Examples 1-3

[0044] The above results show that the sweet potato beverages prepared in Examples 1-3 all contain a large amount of maltose, glucose and fructose components. The sterilized precipitated upper layer liquid is saccharified to decompose into maltose and glucose, so as to achieve a sweet taste effect without adding any sweeteners, acidulants, flavors, etc. to enhance the taste, thereby reducing costs and being more green and natural. In addition, since the precipitation time of the upper layer liquid used in Examples 1-3 is different (without considering factors such as precipitation water temperature and precipitation upper layer liquid), the shorter the precipitation time, the more starch content of the upper layer liquid, and the higher the sugar content after saccharification. Considering that different groups of people have different requirements for the sugar content of beverages, sweet potato beverages with different sugar contents can be quantitatively produced to meet the edible needs of different groups of people.

[0045] At the same time, the upper liquid waste discharged in large quantities by the factory can be utilized to solve the environmental pollution problem and can also be used for production and consumption. Therefore, the research direction of sweet potato beverages utilizing sweet potato starch production wastewater has obvious guiding value.

[0046] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing a sweet potato beverage based on the utilization of sweet potato starch processing wastewater, characterized in that: The main steps include: Step 1: Take liquid: take the upper liquid that has been precipitated for 0.5-2h during the production of sweet potato starch; Step 2: Saccharification: Place the upper liquid in a saccharification container, add α-amylase to decompose the long-chain starch into low-molecular-weight dextrin, saccharify at 72-75°C for 0.5-1h, pH value is 5.6-5.8, then add β-amylase to decompose from the end of the starch chain to form maltose and glucose, saccharify at 60-65°C for 1-2h, pH value is 5.4-5.5; Step 3: Sterilization: The upper layer liquid after saccharification in step 2 is pasteurized at 90°C to 100°C for 10-20 minutes. The resulting product is a sweet potato beverage, which can be filled later.

2. The method for preparing a sweet potato beverage based on the utilization of sweet potato starch processing wastewater according to claim 1, characterized in that: The starch content in the upper layer liquid after precipitation for 0.5-2h in step 1 is 10-20%. No filtration is required when taking the liquid. There is a trace amount of powder residue inside, which increases the cellulose content in the liquid. If the precipitation time of the upper layer liquid exceeds 2h, it will ferment and produce sour taste.

3. The method for preparing a sweet potato beverage based on the utilization of sweet potato starch processing wastewater according to claim 1, characterized in that: In step 2, α-amylase can decompose the long chain of amylose or amylopectin into short-chain dextrins composed of 7 to 12 glucose units, and then β-amylase cuts off two glucose units at a time from the end of the short chain to form maltose; the action time of β-amylase is longer than that of α-amylase.

4. The method for preparing a sweet potato beverage based on the utilization of sweet potato starch processing wastewater according to claim 1, characterized in that: The sterilization method in step 3 can also be microwave sterilization for 2-30 minutes.

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