Preparation process of steviol sugar

Abstract

The invention belongs to the field of steviol sugar, and particularly relates to a preparation process of low-sweetness steviol sugar. The invention relates to a steviol sugar preparation process, which comprises: (1) extracting a stock solution, crushing stevia rebaudiana dry leaves, and screening with a 40-70 mesh sieve to obtain stevia rebaudiana powder; the stevia rebaudiana powder and neutral purified water are put into an extraction device to be subjected to water immersion extraction at 40-45 DEG C for 12-48 h, and an extraction stock solution is obtained; (2) concentration and fermentation: centrifuging the extracted stock solution, concentrating until the dosage ratio of stevia rebaudiana powder to neutral purified water is 1: (5-18) g / mL, and then putting into a fermentation tank for natural fermentation; (3) regulating the sugar degree, and preparing the fermented solution into a solution with the sweetness of 24 + / -1; and (4) preparing powder particles, decoloring, and spraying to prepare the powder particles. The prepared steviol sugar has the advantages of being low in calorie, moderate in sweetness, good in stability and the like, the steviol sugar is low in sweetness, almost does not contain calorie, cannot cause violent fluctuation of blood sugar, and can avoid excessive calorie while meeting the requirement for sweetness.

Description

Technical Field

[0001] The invention belongs to the field of steviol sugar, and particularly relates to a preparation process of steviol sugar with low sweetness. Background Art

[0002] Sweetness is the most basic taste that humans like best. It can stimulate people's senses and make people feel happy and happy. Therefore, sweeteners such as sucrose, glucose and fructose are widely used in food, medicine, cosmetics, beverages, oral hygiene products and other industries. However, these sugar substances generally have disadvantages such as low sweetness and high calories. Excessive intake will lead to an increasing risk of various chronic and non-communicable diseases such as dental caries, diabetes, hypertension, obesity and cardiovascular diseases. Therefore, people's demand for high-sweetness, low-calorie and safe sweeteners has increased dramatically.

[0003] Stevia rebaudiana (Bertoni) Hemsl., commonly known as "sweet grass" and "sweet leaf", is a perennial herb native to the alpine grasslands at the junction of Paraguay and Brazil, belonging to the genus Eupatorium of the Asteraceae family. Stevia leaves are rich in a variety of steviol glycosides. They are characterized by high sweetness (200 to 300 times sweeter than sucrose), low calories (calories are about 1 / 300 of sucrose), safety and non-toxicity. In addition, steviol glycosides have the functions of controlling blood sugar, lowering blood pressure, and promoting metabolism. They also have the effects of treating diabetes, obesity, regulating gastric acid, and restoring nerve fatigue. They are deeply favored by obese patients and diabetics. In 1985 and 1990, the National Health Commission approved steviol glycosides as natural sweeteners and medical sweetener excipients for unlimited use. Therefore, stevia has gradually become a hot spot for research and development in the fields of food and medicine.

[0004] Steviol glycosides are a class of compounds found in the leaves of Stevia rebaudiana Bertoni. Steviol glycosides are a general term for the sweet ingredients in Stevia. Since 1908, researchers have begun to characterize the chemical structure of the main sweet ingredients in Stevia, and thus determined that steviol glycosides are tetracyclic diterpene glycosides derived from steviol (aglycone) after the hydroxyl group at C-13 is replaced by other functional groups and / or the carboxyl group at C-19 undergoes esterification reaction. At present, more than 60 types of steviol glycosides have been isolated and identified from Stevia, among which stevioside is the most abundant component in Stevia leaves, accounting for 5-10% of the dry weight of the leaves, followed by rebaudioside A (Reb A), accounting for 2-4% of the dry weight of the leaves. The sweetness of stevioside is 250, the sweetness of rebaudioside A is 300, the sweetness of rebaudioside B is 300, and the sweetness of rebaudioside D is 250.

[0005] Although stevioside has the characteristics of high sweetness and low calories, it still has a significant aftertaste of bitterness even at high purity, which limits its wide application in food and medicine. It is generally believed that the hydrophobic steviol part (i.e., the aglycone part) shared by stevioside compounds is the fundamental reason for its aftertaste of bitterness. At the same time, the type, quantity and connection mode of the hydrophilic substituents at the C-13 and C-19 positions of stevioside significantly affect the sweetness and taste of stevioside. Among them, the sophoryl group at the C-13 position is the main functional group that forms the sweetness of stevioside, and the ester group at the C-19 position is the flavor-enhancing group of stevioside. Therefore, the current research hotspot and focus of stevioside is to modify it by introducing glycosyl units into the structure of stevioside to improve the sweetness and reduce the bitterness.

[0006] Currently, only stevioside can be produced in the world, which is 200 to 300 times sweeter than sucrose, and has high production costs. It is also difficult to control the amount of use in food additives, and it is even more difficult for ordinary people to use it. Therefore, there is still a need for a simple, effective and economical method for preparing steviol glycosides. Summary of the invention

[0007] In view of this, the object of the present invention is to provide a preparation process of low-sweetness steviol sugar to solve the technical problems mentioned in the above background technology.

[0008] In order to achieve the above object, the present invention provides a preparation process of steviol sugar using the following technical scheme:

[0009] A process for preparing steviol sugar comprises the following steps:

[0010] (1) extracting the stock solution, grinding the dried stevia leaves through 40-70 meshes to obtain stevia powder; placing the stevia powder and neutral purified water in an extraction device and performing water immersion extraction at 40-45° C. for 12-48 hours to obtain an extraction stock solution;

[0011] (2) Concentration and fermentation: centrifuging and concentrating the extracted stock solution until the ratio of stevia powder to neutral purified water is 1:5-18 g / mL, and then placing it in a fermentation tank for natural fermentation;

[0012] (3) adjusting the sugar content to make the fermented solution into a solution with a sweetness of 24±1;

[0013] (4) Making into powder particles, decolorizing and spraying to make powder particles.

[0014] Preferably, in step (1), the usage ratio of the stevia powder to neutral purified water is 1:15-30 g / mL.

[0015] Preferably, in step (1), ultrasound assistance is used in the water extraction process, and the voltage of the ultrasound assistance is 120-140V.

[0016] Preferably, in step (2), during the fermentation process, 0.1-5% glucosidase is added based on the total mass of stevia powder and neutral purified water.

[0017] Preferably, in step (2), the temperature of the natural fermentation is 20 to 35° C., and the fermentation time is 1 to 12 hours.

[0018] Preferably, in step (3), regulating the sugar content comprises the following steps: mixing the fermented solution with erythritol to prepare a solution with a sweetness of 24±1.

[0019] Preferably, in step (2) and step (4), the solution with a sweetness of 24±1 is decolorized by membrane separation and sprayed to form powder particles.

[0020] A steviol sugar prepared by adopting the steviol sugar preparation process.

[0021] Application of steviol sugar prepared by adopting the steviol sugar preparation process in food and pharmaceutical industries.

[0022] Beneficial effects:

[0023] (1) Low in calories. For people who need to control their sugar intake, such as diabetics and people who want to lose weight, the steviol sugar prepared by the present invention is a good substitute. It contains almost no calories and will not cause drastic fluctuations in blood sugar. It can satisfy the need for sweetness while avoiding excess calories.

[0024] (2) Moderate sweetness: The sweetness of the steviol sugar prepared by the present invention is 24±1 degrees. In cooking and food processing, the sweetness of steviol sugar is the same as that of ordinary sucrose. Normal use can achieve the required sweetness without changing the texture and taste of the food.

[0025] (3) Good stability. Stevia can still maintain its sweetness under different temperature and pH conditions and is suitable for a variety of cooking methods and food recipes, such as baked goods, beverages, etc.

[0026] (4) Friendly to teeth: Steviol sugar will not be metabolized by oral bacteria to produce acidic substances like sucrose, thus causing tooth decay, thus helping to maintain oral health. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is further described in detail below through specific implementation methods.

[0028] Example 1

[0029] A process for preparing steviol sugar comprises the following steps:

[0030] (1) Extracting the stock solution, crushing the dried stevia leaves through 40 meshes to obtain stevia powder; placing the stevia powder and neutral purified water in an extraction device and extracting at 40°C for 48 hours to obtain an extraction stock solution; the dosage ratio of the stevia powder to the neutral purified water is 1:15 g / mL.

[0031] (2) Concentrated fermentation: centrifuge the extracted stock solution, concentrate it to a ratio of stevia powder to neutral purified water of 1:5 g / mL, and then place it in a fermenter for natural fermentation; during the fermentation process, add 0.1% glucosidase based on the total mass of stevia powder and neutral purified water; the temperature of natural fermentation is 20°C, and the fermentation time is 4 hours.

[0032] (3) Regulating the sugar content, the fermented solution is mixed with erythritol to prepare a solution with a sweetness of 24±1.

[0033] (4) Making powder particles: decolorizing the solution with a sweetness of 24±1 by membrane separation and spraying to make powder particles.

[0034] Example 2

[0035] A process for preparing steviol sugar comprises the following steps:

[0036] (1) Extracting the stock solution, crushing the dried stevia leaves through 50 meshes to obtain stevia powder; placing the stevia powder and neutral purified water in an extraction device and extracting them at 45° C. for 36 hours to obtain an extraction stock solution; the dosage ratio of the stevia powder to the neutral purified water is 1:20 g / mL.

[0037] (2) Concentrated fermentation: centrifuge the extracted stock solution, concentrate it to a ratio of stevia powder to neutral purified water of 1:10 g / mL, and then place it in a fermenter for natural fermentation; during the fermentation process, add 1% glucosidase based on the total mass of stevia powder and neutral purified water; the temperature of natural fermentation is 25°C, and the fermentation time is 6 hours.

[0038] (3) Regulating the sugar content, the fermented solution is mixed with erythritol to prepare a solution with a sweetness of 24±1.

[0039] (4) Making powder particles: decolorizing the solution with a sweetness of 24±1 by membrane separation and spraying to make powder particles.

[0040] Example 3

[0041] A process for preparing steviol sugar comprises the following steps:

[0042] (1) Extracting the stock solution, crushing the dried stevia leaves through 70 meshes to obtain stevia powder; placing the stevia powder and neutral purified water in an extraction device and extracting them at 45° C. for 48 hours to obtain an extraction stock solution; the dosage ratio of the stevia powder to the neutral purified water is 1:30 g / mL.

[0043] (2) Concentrated fermentation: centrifuge the extracted stock solution, concentrate it to a ratio of stevia powder to neutral purified water of 1:18 g / mL, and then place it in a fermenter for natural fermentation; during the fermentation process, add 5% glucosidase based on the total mass of stevia powder and neutral purified water; the temperature of natural fermentation is 30°C, and the fermentation time is 12 h.

[0044] (3) Regulating the sugar content, the fermented solution is mixed with erythritol to prepare a solution with a sweetness of 24±1.

[0045] (4) Making powder particles: decolorizing the solution with a sweetness of 24±1 by membrane separation and spraying to make powder particles.

[0046] Example 4

[0047] A process for preparing steviol sugar comprises the following steps:

[0048] (1) Extracting the stock solution, crushing the dry stevia leaves through 50 meshes to obtain stevia powder; placing the stevia powder and neutral purified water in an extraction device and extracting them in water at 40° C. for 48 hours to obtain an extraction stock solution; the dosage ratio of stevia powder to neutral purified water is 1:15 g / mL; ultrasonic assistance is used in the water extraction process, and the voltage of the ultrasonic assistance is 130 V.

[0049] (2) Concentrated fermentation: centrifuge the extracted stock solution, concentrate it to a ratio of stevia powder to neutral purified water of 1:18 g / mL, and then place it in a fermenter for natural fermentation; during the fermentation process, add 3% glucosidase based on the total mass of stevia powder and neutral purified water; the temperature of natural fermentation is 25°C, and the fermentation time is 1 hour.

[0050] (3) Regulating the sugar content, the fermented solution is mixed with erythritol to prepare a solution with a sweetness of 24±1.

[0051] (4) Making powder particles: decolorizing the solution with a sweetness of 24±1 by membrane separation and spraying to make powder particles.

[0052] Example 5

[0053] A process for preparing steviol sugar comprises the following steps:

[0054] (1) Extracting the stock solution, crushing the dry stevia leaves through 50 meshes to obtain stevia powder; placing the stevia powder and neutral purified water in an extraction device and extracting them at 40° C. for 48 hours to obtain an extraction stock solution; the dosage ratio of stevia powder to neutral purified water is 1:15 g / mL; ultrasonic assistance is used in the water extraction process, and the voltage of the ultrasonic assistance is 140 V.

[0055] (2) Concentrated fermentation: centrifuge the extracted stock solution, concentrate it to a ratio of stevia powder to neutral purified water of 1:18 g / mL, and then place it in a fermenter for natural fermentation; during the fermentation process, add 3% glucosidase based on the total mass of stevia powder and neutral purified water; the temperature of natural fermentation is 25°C, and the fermentation time is 1 hour.

[0056] (3) Regulating the sugar content, the fermented solution is mixed with erythritol to prepare a solution with a sweetness of 24±1.

[0057] (4) Making powder particles: decolorizing the solution with a sweetness of 24±1 by membrane separation and spraying to make powder particles.

[0058] Comparative Example 1

[0059] A process for preparing steviol sugar comprises the following steps:

[0060] (1) Extracting the stock solution, crushing the dried stevia leaves through 50 meshes to obtain stevia powder; placing the stevia powder and neutral purified water in an extraction device and extracting them at 45° C. for 36 hours to obtain an extraction stock solution; the dosage ratio of the stevia powder to the neutral purified water is 1:20 g / mL.

[0061] (2) Concentrated fermentation: centrifuge the extracted stock solution, concentrate it to a ratio of stevia powder to neutral purified water of 1:10 g / mL, and then place it in a fermenter for natural fermentation; during the fermentation process, add 1% glucosidase based on the total mass of stevia powder and neutral purified water; the temperature of natural fermentation is 25°C, and the fermentation time is 6 hours.

[0062] (6) Making powder particles: the fermented solution is decolorized by membrane separation and sprayed to make powder particles.

[0063] Compared with sucrose, the steviol sugar prepared by the present invention has lower sweetness, no licorice taste, significantly reduced bitterness in the mouth, and no aftertaste or astringency. The present invention uses professional taste evaluation as an evaluation index, and comprehensively evaluates the taste of the steviol sugar by scoring six dimensions (sweetness, licorice taste, bitterness in the mouth, astringency, aftertaste and aftertaste). There is no need to perform component analysis on the steviol sugar of the present invention, and the method is simple and easy.

[0064] The steviol sugar prepared by the present invention has the advantage of low calories. For people who need to control sugar intake, such as diabetics and people who want to lose weight, the steviol sugar prepared by the present invention is a good substitute. It contains almost no calories, will not cause drastic fluctuations in blood sugar, and can avoid excess calories while meeting the demand for sweetness. The steviol sugar prepared by the present invention has a moderate sweetness. The sweetness of the steviol sugar prepared by the present invention is 24±1 degrees. In cooking and food processing, the sweetness of steviol sugar is the same as that of ordinary sucrose. It can achieve the required sweetness by normal use without changing the texture and taste of the food.

[0065] The steviol sugar prepared by the present invention has the advantage of good stability. Under different temperature and pH conditions, the steviol sugar can still maintain its sweetness and is suitable for a variety of cooking methods and food recipes, such as baked food, beverages, etc. The steviol sugar prepared by the present invention is friendly to teeth. Unlike sucrose, the steviol sugar will not be metabolized by oral bacteria to produce acidic substances, thereby causing tooth decay, and is helpful to maintain oral health.

[0066] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A process for preparing steviol sugar, characterized in that: The following steps are involved: (1) extracting the stock solution, grinding the dried stevia leaves through 40-70 meshes to obtain stevia powder; placing the stevia powder and neutral purified water in an extraction device and performing water immersion extraction at 40-45° C. for 12-48 hours to obtain an extraction stock solution; (2) Concentration and fermentation: centrifuging and concentrating the extracted stock solution until the ratio of stevia powder to neutral purified water is 1:5-18 g / mL, and then placing it in a fermentation tank for natural fermentation; (3) adjusting the sugar content to make the fermented solution into a solution with a sweetness of 24±1; (4) Making into powder particles, decolorizing and spraying to make powder particles.

2. The process for preparing steviol sugar according to claim 1, characterized in that: In step (1), the usage ratio of the stevia powder to neutral purified water is 1:15-30 g / mL.

3. The process for preparing steviol sugar according to claim 1, characterized in that: In step (1), ultrasound assistance is used in the water extraction process, and the voltage of the ultrasound assistance is 120-140V.

4. The process for preparing steviol sugar according to claim 1, characterized in that: In step (2), during the fermentation process, 0.1-5% glucosidase is added based on the total mass of stevia powder and neutral purified water.

5. The process for preparing steviol sugar according to claim 1, characterized in that: In step (2), the temperature of the natural fermentation is 20 to 35° C., and the fermentation time is 1 to 12 hours.

6. The process for preparing steviol sugar according to claim 1, characterized in that: In step (3), the sugar content control comprises the following steps: mixing the fermented solution with erythritol to prepare a solution with a sweetness of 24±1.

7. The process for preparing steviol sugar according to claim 1, characterized in that: In step (2) and step (4), the solution with a sweetness of 24±1 is decolorized by membrane separation and sprayed to form powder particles.

8. A steviol sugar prepared by the process for preparing steviol sugar according to any one of claims 1 to 7.

9. Application of steviol sugar prepared by the process for preparing steviol sugar according to any one of claims 1 to 7 in food and pharmaceutical industries.