Comprehensive treatment process of stevioside production tailing RD raw material sugar

Abstract

The invention relates to the technical field of stevioside, in particular to a comprehensive treatment process of stevioside production tailing RD raw material sugar, which comprises the following steps: adding a water dissolving solution into the RD raw material sugar, adding laccase for treatment, filtering, feeding the collected filtrate into an anion resin column, a cation resin column and a macroporous adsorption resin column which are sequentially connected in series, drying the collected effluent to obtain solid powder, enabling the dissolved feed liquid to enter a medium-low pressure chromatographic column, sequentially treating by using a first eluent, a second eluent, a third eluent and a fourth eluent, and evaporating the collected second eluent to dryness to obtain a novel sweetening agent product; evaporating the collected third eluent to dryness, then carrying out methanol crystallization treatment, and drying the collected crystals to obtain an RA product with the content of more than 97%; and evaporating the fourth eluent to dryness, adding water for dissolving, adjusting to acidity, adding water or ethanol for crystallization treatment, and drying the crystal to obtain an RB product with the content of more than 95%. According to the process method, a high-purity RB product, a high-purity RA product and a novel sweetening agent product are obtained.

Description

Technical Field

[0001] This invention relates to the field of stevia technology, and in particular to a comprehensive processing technology for RD raw material sugar, a byproduct of stevia production. Background Technology

[0002] In the production of stevia, the component with relatively high RD (residual organic matter) content is separated from the stevia extract and then dried. This remaining sugar is called RD raw sugar. RD raw sugar suffers from poor taste and appearance, severely impacting its sales value and market competitiveness. Currently, the industry primarily uses resin methods or activated carbon adsorption for decolorizing RD raw sugar, but these methods generally suffer from low processing efficiency and unsatisfactory decolorization results, leading to resource waste and low economic value. Therefore, it is necessary to develop a comprehensive treatment process for RD raw sugar, a byproduct of stevia production. Summary of the Invention

[0003] The technical problem to be solved by this invention is to provide a comprehensive processing technology for RD raw sugar, a byproduct of stevia production, which addresses the shortcomings of existing technologies. This processing technology can produce higher-value RB and RA, and also yields novel sweetener products, thereby increasing the economic benefits for enterprises.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0005] A comprehensive processing technology for stevia production waste (RD raw material sugar) includes the following process steps:

[0006] (1) Take the RD raw sugar, add laccase to the sugar solution after dissolving it in water, control the reaction temperature and reaction time, filter after the reaction is completed, and collect the filtrate for later use.

[0007] (2) Take the filtrate from step (1) and sequentially enter an anion exchange resin column, a cation exchange resin column and a macroporous resin column connected in series. Collect the effluent discharged from the macroporous resin column, and after drying, obtain a solid powder for later use.

[0008] (3) Take the solid powder described in step (2), add water or ethanol with a volume concentration of less than 10% to dissolve it, and enter the resulting liquid into a medium-low pressure chromatographic column. After the feed is completed, use the first eluent, the second eluent, the third eluent and the fourth eluent for elution. Discard the first eluent collected, and keep the second eluent, the third eluent and the fourth eluent collected for later use.

[0009] (4) Take the second eluent from step (3), evaporate it to dryness, and the resulting solid is the new sweetener product; take the third eluent, evaporate it to dryness, and then crystallize it with methanol with a volume concentration of not less than 90%. After drying the collected crystals, a product with a content of more than 97% RA can be obtained; take the fourth eluent, evaporate it to dryness, add water to dissolve it and adjust the pH to acidic, add water or ethanol with a volume concentration of less than 10% for crystallization treatment, and after drying the collected crystals, a product with a content of more than 95% RB can be obtained.

[0010] As an improved technical solution, the solid content of the sugar solution in step (1) is 10-15%, and the amount of laccase added is 0.5-1.5‰ of the solid content of the sugar solution.

[0011] As an improved technical solution, in step (1), the reaction temperature is controlled at 40-45℃ and the reaction time is 6-8h.

[0012] As an improved technical solution, in step (2), the filtrate is sequentially fed into an anion exchange resin column, a cation exchange resin column, and a macroporous resin column connected in series at a flow rate of 0.2-0.4 BV / h per column volume; the packing material in the anion exchange resin column is an acrylic-based strong basic anion exchange resin or a styrene-based weak basic anion exchange resin; the packing material in the cation exchange resin column is a styrene-based sulfonic acid type strong acid cation exchange resin; and the packing material in the macroporous adsorption resin column is a non-polar macroporous adsorption resin or a moderately polar macroporous adsorption resin.

[0013] As an improved technical solution, the volume concentration of ethanol in step (3) is 2-5%.

[0014] As an improved technical solution, the solid content of the feed solution in step (3) is 5-20%, and the feed solution enters the medium-low pressure chromatographic column at a flow rate of 0.5-1.5 BV / h. The medium-low pressure chromatographic column is filled with C18 packing material, and the particle size of the C18 packing material is 20-50 μm, the pore size is 100-150 Å, and the specific surface area is 300-400 m². 2 / g.

[0015] As an improved technical solution, in step (3), the first eluent is ethanol with a volume concentration of 10-20%, the second eluent is ethanol with a volume concentration of 25-30%, the third eluent is ethanol with a volume concentration of 35-40%, and the fourth eluent is ethanol with a volume concentration of 45-50%.

[0016] As an improved technical solution, the novel sweetener product in step (4) contains RD, RM, RO, RN and RE. The total glycoside content of the novel sweetener product is 55-65%, RD is 8-15%, RM is 7-10%, RO is 25-35%, RN is 10-20% and RE is 5-8%.

[0017] As an improved technical solution, the volume concentration of methanol in step (4) is 90-92%, and the volume concentration of ethanol is 2%-10%.

[0018] As an improved technical solution, in step (4), the fourth eluent is evaporated to dryness and then dissolved in water, and the pH is adjusted to 3.5-4.5 using hydrochloric acid.

[0019] After adopting the above technical solution, the beneficial effects of the present invention are:

[0020] This invention uses RD (diethyltoluene) raw sugar as a raw material. The sugar solution, dissolved in water, is enzymatically hydrolyzed with laccase to effectively remove some impurities and pigments. After filtration, the collected filtrate is fed into a series of anion exchange resin columns, cation exchange resin columns, and macroporous adsorption resin columns. The collected eluent is dried to obtain a solid powder. The dissolved solution is then fed into a medium-low pressure chromatographic column, where it is treated sequentially with a first, second, third, and fourth eluent. The collected second eluent is evaporated to dryness to obtain a novel sweetener product. The collected third eluent is evaporated to dryness and then crystallized in methanol. The collected crystals are dried to obtain a RA (rare radix) product with a purity greater than 97%. The fourth eluent is evaporated to dryness, dissolved in water, and adjusted to acidity. It is then crystallized in water or ethanol with a volume concentration less than 10%. The collected crystals are dried to obtain an RB (refined radix) product with a purity greater than 95%. This process effectively processes RD raw sugar to obtain high-purity RB, RA, and novel sweetener products, increasing product value and bringing economic benefits to enterprises. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] Example 1

[0023] (1) Take 100g of RD raw sugar (total glycosides 40.1%, RD 3.4%, RM 3.5%, RA 11.1%, STV 1.1%, RF 0.2%, RC 0.7%, RB 1.6%, RE 2.2%, RO 8.2%, RN 8.1%), add water to dissolve and obtain 1L of sugar solution with a solid content of 10%, add laccase with a solid content of 0.5‰ of the sugar solution, control the reaction temperature at 40℃, react for 6h and then filter, collect 1L of filtrate for later use;

[0024] (2) Take 1L of the filtrate from step (1) and sequentially feed it into a series of 200ml anion exchange resin column (the packing material is acrylic strong base anion exchange resin, specifically Zhengguang D730), a 200ml cation exchange resin column (the packing material is styrene sulfonic acid type strong acid cation exchange resin, specifically Zhengguang 001X7FD), and a 200ml macroporous resin column (the packing material is non-polar macroporous adsorption resin, specifically Zhengguang SD333). Collect 0.6L of the effluent discharged from the macroporous resin column, and after drying, obtain 50g of solid powder for later use.

[0025] (3) Take 50g of the solid powder from step (2), dissolve it in water to obtain 1L of a solid content solution of 5%, and inject it into a 1L medium-low pressure chromatographic column (with C18 packing material, particle size of 20um, pore size of 100Å, and specific surface area of ​​300m²) at a flow rate of 0.5BV / h. 2 / g), after the feed is finished, elution is carried out sequentially with 5L of the first eluent (10% ethanol by volume), 5L of the second eluent (25% ethanol by volume), 2L of the third eluent (35% ethanol by volume) and 3L of the fourth eluent (45% ethanol by volume). The first eluent collected is discarded, and the 5L of the second eluent, 2L of the third eluent and 3L of the fourth eluent collected are reserved for use.

[0026] (4) Take 5L of the second eluent from step (3), evaporate to dryness to obtain 8g of a white novel sweetener product (total glycoside content is 55%, RD is 8%, RM is 7%, RO is 25%, RN is 10%, RE is 5%); take 2L of the third eluent, evaporate to dryness to obtain 16g of solid, add 90% methanol at a ratio of 1:3 (the ratio of material to liquid is in g / ml) for crystallization treatment, and dry the collected crystals to obtain a white RA product with a yield of 9.6g, a content of 98.2%, and a weight yield of 60%; take 3L of the fourth eluent, evaporate to dryness to obtain 9g of solid, dissolve in water, adjust the pH to 3.5, add water at a ratio of 1:9 (the ratio of material to liquid is in g / ml) for crystallization treatment, and dry the collected crystals to obtain a white RB product with a yield of 6.78g, a content of 95.6%, and a weight yield of 75.3%.

[0027] Example 2

[0028] (1) Take 150g of RD raw sugar (total glycosides 42.6%, RD 4.1%, RM 4.5%, RA 10.6%, STV 0.8%, RF 0.1%, RC 0.8%, RB 1.8%, RE 2.5%, RO 9%, RN 8.4%), add water to dissolve and obtain 1.2L of sugar solution with a solid content of 12.5%. Add laccase with a solid content of 1‰ of the sugar solution, control the reaction temperature at 43℃, react for 7h and then filter. Collect 1.2L of filtrate for later use.

[0029] (2) Take 1.2L of the filtrate from step (1) and sequentially feed it into a series of 200ml anion exchange resin column (the packing material is styrene-based weakly basic anion exchange resin, specifically Zhengguang ZGA455H166), 200ml cation exchange resin column (the packing material is styrene-based sulfonic acid type strong acid cation exchange resin, specifically Zhengguang D001FD), and 200ml macroporous resin column (the packing material is neutral polar macroporous adsorption resin, specifically Lanxiao LXS868). Collect 1L of the effluent discharged from the macroporous resin column, and after drying, obtain 78g of solid powder for later use.

[0030] (3) Take 60g of the solid powder from step (2), dissolve it in 2% ethanol (volume concentration) to obtain 0.6L of a feed solution with a solid content of 15%, and inject it into a 1L medium-low pressure chromatographic column (internal packing is C18, the particle size of C18 packing is 30um, the pore size is 125A, and the specific surface area is 330m²) at a flow rate of 1BV / h. 2 / g, after the feed is completed, elution is carried out sequentially with 5L of the first eluent (15% ethanol by volume), 5L of the second eluent (28% ethanol by volume), 2.5L of the third eluent (38% ethanol by volume), and 4L of the fourth eluent (48% ethanol by volume). The first eluent collected is discarded, and the corresponding 4.8L of the second eluent, 2.5L of the third eluent, and 4L of the fourth eluent are kept for later use.

[0031] (4) Take 4.8L of the second eluent from step (3), evaporate to dryness to obtain 9.8g of a white novel sweetener product (total glycoside content 88%, RD 15%, RM 10%, RO 35%, RN 20%, RE 8%); take 2.5L of the third eluent, evaporate to dryness to obtain 19.5g of solid, add 92% methanol at a material-to-liquid ratio of 1:2.5 (material-to-liquid ratio unit is g / ml) for crystallization treatment, and dry the collected crystals. The yield of white RA product is 12.67g, with a purity of 97.8% and a weight yield of 65%. Take 4L of the fourth eluent, evaporate it to dryness, and dissolve the resulting 9.73g solid in water. Adjust the pH to 4, and add 2% ethanol at a material-to-liquid ratio of 1:11 (material-to-liquid ratio in g / ml) for crystallization. After drying the collected crystals, the yield of white RB product is 7.1g, with a purity of 95.7% and a weight yield of 73%.

[0032] Example 3

[0033] (1) Take 120g of RD raw sugar (total glycosides 43.9%, RD 5%, RM 4.9%, RA 11.2%, STV 0.7%, RF 0.2%, RC 0.6%, RB 1.5%, RE 2.9%, RO 9.5%, RN 7.4%), add water to dissolve and obtain 0.8L of sugar solution with a solid content of 15%. Add laccase with a solid content of 1.5‰ of the sugar solution, control the reaction temperature at 45℃, react for 8h and then filter. Collect 0.8L of filtrate for later use.

[0034] (2) Take 0.8L of the filtrate from step (1) and sequentially feed it into a series of 200ml anion exchange resin column (the packing material is styrene-based weakly basic anion exchange resin, specifically Zhengguang D730), a 200ml cation exchange resin column (the packing material is styrene-based sulfonic acid type strong acid cation exchange resin, specifically Zhengguang 001X7FD), and a 200ml macroporous resin column (the packing material is medium polar macroporous adsorption resin, specifically Lanxiao LXS868). Collect 0.6L of the effluent discharged from the macroporous resin column, and after drying, obtain 62g of solid powder for later use.

[0035] (3) Take 55g of the solid powder from step (2), dissolve it in 3% ethanol (v / v) to obtain 0.55L of a solid content solution with a solid content of 10%, and inject it into a 1L medium-low pressure chromatographic column (with C18 packing material, C18 packing material with a particle size of 40μm, a pore size of 145Å, and a specific surface area of ​​370m²) at a flow rate of 1.3 BV / h. 2 / g), after the feed is completed, elution is carried out sequentially with 4.5L of the first eluent (18% ethanol by volume), 5L of the second eluent (28% ethanol by volume), 2.5L of the third eluent (38% ethanol by volume), and 3.5L of the fourth eluent (48% ethanol by volume). The first eluent collected is discarded, and the 4.5L second eluent, 2.2L third eluent, and 3.1L fourth eluent collected are reserved for use.

[0036] (4) Take 4.5L of the second eluent from step (3), evaporate to dryness to obtain 8g of a white novel sweetener product (total glycoside content 78.4%, RD 12.5%, RM 8.7%, RO 32.2%, RN 18.2%, RE 6.8%); take 2.2L of the third eluent, evaporate to dryness to obtain 18g of solid, add 90% methanol at a ratio of 1:2.5 (solid-liquid ratio unit is g / ml) for crystallization treatment, and collect the crystals. After drying, a white RA product with a yield of 9.9g, a purity of 98.6%, and a weight yield of 55% is obtained. Take 3.1L of the fourth eluent, evaporate it to dryness, and dissolve the resulting 7g solid in water. Adjust the pH to 4.2, and add 5% ethanol at a solid-liquid ratio of 1:12 (solid-liquid ratio in g / ml) for crystallization. After drying the collected crystals, a white RB product with a yield of 5.04g, a purity of 96.7%, and a weight yield of 72% is obtained.

[0037] Example 4

[0038] (1) Take 130g of RD raw sugar (total glycosides 43.6%, RD 4.3%, RM 4.2%, RA 12.6%, STV 0.8%, RF 0.1%, RC 0.7%, RB 1.8%, RE 2.6%, RO 8.5%, RN 8.0%), add water to dissolve and obtain 1L of sugar solution with a solid content of 15%. Add laccase with a solid content of 0.8‰ of the sugar solution, control the reaction temperature at 43℃, react for 8 hours and then filter. Collect 1L of filtrate for later use.

[0039] (2) Take 1L of the filtrate from step (1) and sequentially feed it into a series of 200ml anion exchange resin column (the packing material is acrylic strong base anion exchange resin, specifically Zhengguang ZGA455H166), a 200ml cation exchange resin column (the packing material is styrene sulfonic acid type strong acid cation exchange resin, specifically Zhengguang 001X7FD), and a 200ml macroporous resin column (the packing material is non-polar macroporous adsorption resin, specifically Zhengguang SD333). Collect 0.78L of the effluent discharged from the macroporous resin column, and after drying, obtain 77g of solid powder for later use.

[0040] (3) Take 60g of the solid powder from step (2), dissolve it in 5% ethanol (v / v) to obtain 0.3L of a solid content solution with a solid content of 20%, and inject it into a 1L medium-low pressure chromatographic column (internal C18 packing, C18 packing particle size 50um, pore size 150A, specific surface area 400m²) at a flow rate of 1.3 BV / h. 2 After feeding, the feed is eluted sequentially with 5L of the first eluent (20% ethanol by volume), 4L of the second eluent (30% ethanol by volume), 2L of the third eluent (40% ethanol by volume), and 3L of the fourth eluent (50% ethanol by volume). The first eluent collected is discarded, and the corresponding 4.2L of the second eluent, 1.9L of the third eluent, and 3L of the fourth eluent are kept for later use.

[0041] (4) Take 4.2L of the second eluent from step (3), evaporate to dryness to obtain 11g of a white novel sweetener product (total glycoside content 70.4%, RD 10.6%, RM 8.3%, RO 28.6%, RN 15.6%, RE 7.3%); take 1.9L of the third eluent, evaporate to dryness to obtain 22g of solid, add 91% methanol at a material-to-liquid ratio of 1:3 (material-to-liquid ratio unit is g / ml) for crystallization treatment, and dry the collected crystals. The yield of white RA product is 13.64g, with a purity of 98.1% and a weight yield of 62%. Take 3L of the fourth eluent, evaporate it to dryness, and dissolve the resulting 7g solid in water. Adjust the pH to 3.8, and then add 10% ethanol at a ratio of 1:10.5 (the ratio is in g / ml) for crystallization. After drying the collected crystals, the yield of white RB product is 4.5g, with a purity of 97.6% and a weight yield of 64.28%.

[0042] To better demonstrate that the process of the present invention can yield high-value RB products, RA products, and novel sweetener products, the following comparative examples are provided with reference to Example 2.

[0043] Comparative Example 1

[0044] Unlike Example 2, in step (1), the sugar solution of the RD raw material sugar dissolved in water was not treated with laccase, and the rest of the operation was the same. In step (4), the second eluent was evaporated to obtain 5g of yellow sweetener product (this product has a poor taste and off-flavors, and cannot be called a new sweetener product; the total glycoside content is 28.2%, RD is 5.4%, RM is 6.2%, RO is 5.9%, RN is 4.8%, and RE is 5.9%); a yellow RA product with a yield of 11g, a content of 56.7%, and a weight yield of 34.6% was obtained; and a yellow RB product with a yield of 7g, a content of 58%, and a weight yield of 45% was obtained.

[0045] Comparative Example 2

[0046] Unlike Example 2, the reaction temperature in step (1) was controlled at 35°C, while the rest of the operation was the same. In step (4), the second eluent was evaporated to obtain 5g of a yellow novel sweetener (this product has a poor taste and off-flavors, and cannot be called a novel sweetener product; the total glycoside content is 29.7%, RD is 6%, RM is 4.8%, RO is 8%, RN is 7%, and RE is 3.9%); a yellow RA product with a yield of 15g, a content of 60%, and a recovery rate of 40% was obtained; and a yellow RB product with a yield of 8g, a content of 65%, and a recovery rate of 56% was obtained.

[0047] Comparative Example 3

[0048] Unlike Example 2, the reaction temperature in step (1) was controlled at 50°C, while the rest of the operation was the same. In step (4), the second eluent was evaporated to obtain 4g of a yellow sweetener product (this product has a poor taste and off-flavors, and cannot be called a novel sweetener product; the total glycoside content is 30%, RD is 6.1%, RM is 5%, RO is 8%, RN is 7%, and RE is 3.9%); a yellow RA product with a yield of 12g, a content of 55%, and a weight yield of 51% was obtained; and a yellow RB product with a yield of 7.2g, a content of 63%, and a weight yield of 49% was obtained.

[0049] Comparative Example 4

[0050] Unlike Example 2, the reaction temperature in step (1) was controlled at 35°C, while the rest of the operation was the same. In step (4), the second eluent was evaporated to obtain 6g of a yellow sweetener product (this product has a poor taste and off-flavors, and cannot be called a novel sweetener product; the total glycoside content is 32.1%, RD is 7.1%, RM is 5.5%, RO is 8.2%, RN is 7.1%, and RE is 4.2%); a yellow RA product with a yield of 11g, a content of 50%, and a weight yield of 53% was obtained; and a yellow RB product with a yield of 6.6g, a content of 60%, and a weight yield of 52% was obtained.

[0051] Comparative Example 5

[0052] Unlike Example 2, the packing material in the anion exchange resin column in step (2) is Zhengguang D890, and the rest of the operation is the same. In step (4), the second eluent was evaporated to obtain 5.6g of a yellow sweetener product (this product has a poor taste and off-flavors, and cannot be called a new sweetener product; the total glycoside content is 29.3%, RD is 6.6%, RM is 4.3%, RO is 7.6%, RN is 7.3%, and RE is 3.5%); a yellow RA product with a yield of 9.5g, a content of 47%, and a yield of 48% was obtained; and a yellow RB product with a yield of 7.1g, a content of 58%, and a yield of 51% was obtained.

[0053] Comparative Example 6

[0054] Unlike Example 2, the packing material in the cation exchange resin column in step (2) is Zhengguang D152, and the rest of the operation is the same. In step (4), the second eluent was evaporated to obtain 6.3g of a yellow novel sweetener (this product has a poor taste and off-flavors, and cannot be called a novel sweetener product; the total glycoside content is 28.3%, RD is 5.9%, RM is 4.9%, RO is 6.8%, RN is 6.5%, and RE is 4.2%); a yellow RA product with a yield of 9.2g, a content of 42%, and a weight yield of 51% was obtained; and a yellow RB product with a yield of 6.8g, a content of 55%, and a weight yield of 50% was obtained.

[0055] Comparative Example 7

[0056] Unlike Example 2, the filler in the macroporous resin column in step (2) is Lanxiao LX-68M, and the rest of the operation is the same. In step (4), the second eluent was evaporated to obtain 7g of a yellow novel sweetener (this product has a poor taste and off-flavors, and cannot be called a novel sweetener product; the total glycoside content is 17.8%, RD is 3%, RM is 2.6%, RO is 5.4%, RN is 4.5%, and RE is 2.3%); a yellow RA product with a yield of 8.7g, a content of 38%, and a weight yield of 60% was obtained; and a yellow RB product with a yield of 7.1g, a content of 40%, and a yield of 55% was obtained.

[0057] Comparative Example 8

[0058] Unlike Example 2, the packing material for the medium-low pressure chromatographic column in step (3) is Suqing CX-10, and the rest of the operation is the same. In step (4), the second eluent is evaporated to dryness to obtain 0g of the new sweetener product; RA product with a yield of 0g is obtained; RB product with a yield of 0g is obtained.

[0059] Comparative Example 9

[0060] Unlike Example 2, the packing material for the medium-low pressure chromatographic column in step (3) is comma-based biological NH2, and the rest of the operation is the same. In step (4), the second eluent was evaporated to dryness to obtain 35g of a white novel sweetener product (the taste is not as good as that of Example 2, with a bitter aftertaste) (total glycoside content is 43.3%, RD is 4%, RM is 2%, RO is 5%, RN is 4.2%, RE is 2.3%, RA is 22%, RC is 1.2%, RB is 2.6%); RA product with a yield of 0g was obtained; RB product with a yield of 0g was obtained.

[0061] Comparative Example 10

[0062] Unlike Example 2, in step (3), the first eluent was 8% ethanol (v / v), the second eluent was 22% ethanol (v / v), the third eluent was 32% ethanol (v / v), and the fourth eluent was 42% ethanol (v / v). The remaining operations were the same. In step (4), the second eluent was evaporated to dryness to obtain 30g of a yellow novel sweetener product (poor taste, mixed with impurities, bitter, off-flavors, and astringent; total glycoside content was 12.3%, RD was 1.6%, RM was 2.6%, RO was 3%, RN was 2.9%, and RE was 2.2%). The change in eluents led to serious differences in the subsequently collected samples, making RA and RB crystallization impossible.

[0063] Comparative Example 11

[0064] Unlike Example 2, in step (4), after the third eluent was evaporated to dryness, it was crystallized with methanol at a volume concentration of 88%, and the rest of the operation was the same. In step (4), the second eluent was evaporated to dryness to obtain 10g of a white novel sweetener product (total glycoside content of 89%, RD of 15.5%, RM of 10%, RO of 35.2%, RN of 20.3%, RE of 8%); RA product with a yield of 0g was obtained; RB product with a yield of 7g, a content of 97.2%, and a weight yield of 65% was obtained.

[0065] Comparative Example 12

[0066] Unlike Example 2, in step (4), after the third eluent was evaporated to dryness, it was crystallized with methanol at a volume concentration of 94%, while the rest of the operation was the same. In step (4), the second eluent was evaporated to dryness to obtain 9.5g of a white novel sweetener product (total glycoside content of 88%, RD of 15.2%, RM of 9.8%, RO of 34.2%, RN of 20.5%, RE of 8.3%); RA product with a yield of 0g was obtained; RB product with a yield of 7g, a content of 97.5%, and a weight yield of 62% was obtained.

[0067] Comparative Example 13

[0068] Unlike Example 2, in step (4), the fourth eluent was evaporated to dryness and then dissolved in water. The pH was adjusted to 3 using hydrochloric acid, and the rest of the operation was the same. In step (4), the second eluent was evaporated to dryness to obtain 9.7g of a white novel sweetener product (total glycoside content of 88%, RD of 14.5%, RM of 10.5%, RO of 35%, RN of 20%, RE of 8%); a white RA product with a yield of 12.6g, a content of 98.5%, and a weight yield of 64.28% was obtained; and a pale yellow RB product with a yield of 5g, a content of 33%, and a weight yield of 20% was obtained.

[0069] Comparative Example 14

[0070] Unlike Example 2, in step (4), the fourth eluent was evaporated to dryness and then dissolved in water. The pH was adjusted to 5 using hydrochloric acid, and the rest of the operation was the same. In step (4), the second eluent was evaporated to dryness to obtain 9.8g of a white novel sweetener product (total glycoside content of 87.8%, RD of 14.5%, RM of 10.3%, RO of 35%, RN of 20%, RE of 8%); a white RA product with a yield of 11.8g, a content of 98.1%, and a weight yield of 64.5% was obtained; and a pale yellow RB product with a yield of 3g, a content of 27%, and a weight yield of 19% was obtained.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A comprehensive processing technology for stevia production waste (RD raw sugar), characterized in that, The process includes the following steps: (1) Take the RD raw sugar, add laccase to the sugar solution after dissolving it in water, control the reaction temperature and reaction time, filter after the reaction is completed, and collect the filtrate for later use. (2) Take the filtrate from step (1) and sequentially enter an anion exchange resin column, a cation exchange resin column and a macroporous resin column connected in series. Collect the effluent discharged from the macroporous resin column, and after drying, obtain a solid powder for later use. (3) Take the solid powder described in step (2), add water or ethanol with a volume concentration of less than 10% to dissolve it, and enter the resulting liquid into a medium-low pressure chromatographic column. After the feed is completed, use the first eluent, the second eluent, the third eluent and the fourth eluent for elution. Discard the first eluent collected, and keep the second eluent, the third eluent and the fourth eluent collected for later use. (4) Take the second eluent from step (3), evaporate it to dryness, and the resulting solid is the new sweetener product; take the third eluent, evaporate it to dryness, and then crystallize it with methanol with a volume concentration of not less than 90%. After drying the collected crystals, a product with a content of more than 97% RA can be obtained; take the fourth eluent, evaporate it to dryness, add water to dissolve it and adjust the pH to acidic, add water or ethanol with a volume concentration of less than 10% for crystallization treatment, and after drying the collected crystals, a product with a content of more than 95% RB can be obtained.

2. The comprehensive treatment process for stevia production waste RD raw sugar according to claim 1, characterized in that, The solid content of the sugar solution in step (1) is 10-15%, and the amount of laccase added is 0.5-1.5‰ of the solid content of the sugar solution.

3. The comprehensive treatment process for stevia production waste RD raw sugar according to claim 1, characterized in that, In step (1), the reaction temperature is controlled at 40-45℃ and the reaction time is 6-8h.

4. The comprehensive treatment process for stevia production waste RD raw sugar according to claim 1, characterized in that, In step (2), the filtrate is sequentially fed into an anion exchange resin column, a cation exchange resin column, and a macroporous resin column connected in series at a flow rate of 0.2-0.4 BV / h per column. The packing material in the anion exchange resin column is an acrylic-based strong basic anion exchange resin or a styrene-based weak basic anion exchange resin. The packing material in the cation exchange resin column is a styrene-based sulfonic acid type strong acid cation exchange resin. The packing material in the macroporous adsorption resin column is a non-polar macroporous adsorption resin or a moderately polar macroporous adsorption resin.

5. The comprehensive treatment process for stevia production waste RD raw sugar according to claim 1, characterized in that, The volume concentration of ethanol in step (3) is 2-5%.

6. The comprehensive treatment process for stevia production waste RD raw sugar according to claim 1, characterized in that, The solid content of the feed solution in step (3) is 5-20%, and the feed solution enters the medium-low pressure chromatographic column at a flow rate of 0.5-1.5 BV / h. The medium-low pressure chromatographic column is filled with C18 packing material, and the particle size of the C18 packing material is 20-50 μm, the pore size is 100-150 Å, and the specific surface area is 300-400 m². 2 / g.

7. The comprehensive treatment process for stevia production waste RD raw sugar according to claim 1, characterized in that, In step (3), the first eluent is ethanol with a volume concentration of 10-20%, the second eluent is ethanol with a volume concentration of 25-30%, the third eluent is ethanol with a volume concentration of 35-40%, and the fourth eluent is ethanol with a volume concentration of 45-50%.

8. The comprehensive treatment process for stevia production waste RD raw sugar according to claim 1, characterized in that, The novel sweetener product described in step (4) contains RD, RM, RO, RN and RE. The total glycoside content of the novel sweetener product is 55-65%, RD is 8-15%, RM is 7-10%, RO is 25-35%, RN is 10-20% and RE is 5-8%.

9. The comprehensive treatment process for stevia production waste RD raw sugar according to claim 1, characterized in that, The volume concentration of methanol in step (4) is 90-92%, and the volume concentration of ethanol is 2%-10%.

10. The comprehensive treatment process for stevia production waste RD raw sugar according to claim 1, characterized in that, In step (4), the fourth eluent is evaporated to dryness and then dissolved in water. The pH is adjusted to 3.5-4.5 using hydrochloric acid.