Low-acid reflux, heat-stable rock sugar syrup and preparation method thereof

Abstract

The present invention relates to a low-acid reflux, heat-stable rock sugar syrup and a preparation method thereof, belonging to the technical field of sweeteners. The rock sugar syrup is prepared from the following raw materials in parts by weight: 80 to 90 parts of rock sugar, 0.2 to 0.4 parts of steviol glycosides, 0.5 to 2 parts of maltitol, 0.5 to 2 parts of glucose syrup, 5 to 8 parts of monk fruit extract, 80 to 120 parts of purified water, and sodium citrate. The sodium citrate is used to adjust the pH value of the rock sugar syrup to 5.5 to 6.0. The monk fruit extract is a product obtained by co-fermenting the pulp and peel of fresh monk fruit with Bifidobacterium breve and Pediococcus pentosaceus, and then enzymolyzing it with ficin. The rock sugar syrup of the present invention is added with steviol glycosides and monk fruit extract, which can well maintain the stability of the rock sugar syrup, has good anti-acid reflux properties, and saves the amount of maltitol and glucose syrup.

Description

Technical Field

[0001] The invention belongs to the technical field of sweeteners, and particularly relates to a low-acid-reflux and heat-stable rock sugar syrup and a preparation method thereof. Background Art

[0002] Rock sugar syrup is a thick liquid sweetener made from high fructose corn syrup, white sugar, rock sugar, and other sugars. This mixture is heated, boiled, filtered, and concentrated to create a thick, liquid sweetener. Rock sugar syrup typically has the sweet flavor of rock sugar and is relatively sweet. As a common food and pharmaceutical additive, it's widely used to sweeten and enhance flavors.

[0003] At present, rock sugar syrup has the following problems:

[0004] (1) Due to its composition or production process, some rock sugar syrups contain a high proportion of ingredients such as sucrose. Under certain conditions, these ingredients will undergo chemical reactions to produce acidic substances, resulting in a sour taste. In addition, improper control of processing conditions during the production process may also affect the acidity of rock sugar syrups.

[0005] (2) In terms of thermal stability, some rock sugar syrups may experience decreased stability when used in hot drinks or foods that require heating. For example, during the heating process, rock sugar syrups may decompose, change color, change flavor, or precipitate or crystallize. This not only affects the quality and taste of the product, but also limits its application in certain heat-processed foods.

[0006] To address these issues, researchers have been diligently exploring improvements to the formulation and production process of rock sugar syrup. On the one hand, by optimizing the selection and ratio of raw materials, they are looking for alternatives to some traditional ingredients to reduce acidity and improve thermal stability. For example, replacing part of the sucrose with specific functional sugar alcohols or other sweeteners can maintain sweetness while reducing the production of acidic substances. On the other hand, they are improving the production process to precisely control parameters such as temperature, time, and pH during processing to ensure the stability of the rock sugar syrup.

[0007] In addition, new technologies and methods are being applied to the production of rock sugar syrup. For example, using enzymes to treat raw materials can help improve the properties of the syrup. Alternatively, specialized filtration and separation techniques can be used to remove impurities that could affect stability.

[0008] In practice, however, the improvement is less than ideal. Under certain special conditions, such as acid, alkali, high temperature, and low temperature, instability and acid reversion can occur, resulting in an uneven taste. The acid reversion and thermal stability of rock sugar syrup are crucial to product quality and consumer acceptance. Therefore, food and pharmaceutical manufacturers need to select rock sugar syrup with excellent acid reversion resistance and thermal stability to ensure stable quality and taste during storage and processing, meeting consumer demand. This requires continuous development and improvement of the performance of rock sugar syrup. Summary of the Invention

[0009] The instability and acid reflux problems of existing rock sugar syrup products are difficult to improve, affecting the taste. The present invention provides a low-acid-reflux, heat-stable rock sugar syrup and a preparation method thereof. By adding steviol glycosides and monk fruit extract, the stability of the rock sugar syrup can be well maintained, the acid reflux resistance is good, and the amount of maltitol and glucose syrup can be saved. The specific technical solution is as follows:

[0010] A low-acid reflux and heat-stable rock sugar syrup is prepared from the following raw materials in parts by mass: 80-90 parts of rock sugar, 0.2-0.4 parts of steviol glycosides, 0.5-2 parts of maltitol, 0.5-2 parts of glucose syrup, 5-8 parts of monk fruit extract, 80-120 parts of purified water and sodium citrate, wherein the pH value of the rock sugar syrup is adjusted to 5.5-6.0 by using sodium citrate. The monk fruit extract is a product obtained by co-fermenting the pulp and peel of fresh monk fruit with Bifidobacterium breve and Pediococcus pentosaceus, and then enzymolyzing with ficin.

[0011] In the above technical scheme, the preparation method of the monk fruit extract is as follows: taking the pulp and peel of fresh monk fruit, crushing them to obtain pulp, adding 8 to 10 times the mass of water of the pulp, adding 1% to 3% of glucose by mass of the pulp, adding 0.3% to 1% of Bifidobacterium breve and 0.3% to 1% of Pediococcus pentosaceus by mass of the pulp, anaerobically fermenting at 36°C to 38°C for 8h to 10h, sterilizing at high temperature, cooling to room temperature, adding 0.5% to 1.5% of ficin by mass of the pulp, enzymolyzing at 60°C to 70°C for 2h to 3h, inactivating the enzyme by high temperature, cooling to room temperature, filtering with a 3kDa ultrafiltration membrane to obtain a filtrate below 3kDa, and concentrating to 10% to 15% of the volume of the filtrate to obtain the monk fruit extract.

[0012] In the above-mentioned method for preparing the Momordica grosvenori extract, the bacterial activity of the Bifidobacterium breve is 2 to 20 billion CFU / g; the bacterial activity of the Pediococcus pentosaceus is 2 to 20 billion CFU / g.

[0013] In the above-mentioned method for preparing the Momordica grosvenori extract, the high-temperature sterilization temperature is 70° C. to 85° C. and the time is 15 min to 30 min.

[0014] In the preparation method of the above-mentioned Momordica grosvenori extract, the enzymatic activity of the ficin is 50,000 to 100,000 U / g.

[0015] In the above-mentioned method for preparing the Momordica grosvenori extract, the temperature for high-temperature enzyme inactivation is 70° C. to 85° C. and the time is 15 min to 20 min.

[0016] The method for preparing the low-acid-reflux, heat-stable rock sugar syrup comprises the following steps:

[0017] S1: Boil rock sugar, steviol glycosides, maltitol, glucose syrup and purified water according to their mass ratios to prepare syrup. After the syrup concentration reaches the designed concentration, cool the temperature to 40°C to 50°C to obtain warm syrup.

[0018] S2: adding the monk fruit extract to the warm syrup, mixing evenly, adding sodium citrate, adjusting the pH value of the rock sugar syrup to 5.5-6.0, filtering, sterilizing, and aseptically canning to obtain the rock sugar syrup.

[0019] In the preparation method of the rock sugar syrup, the mass concentration of the glucose syrup is 40% to 60%.

[0020] In the preparation method of the above-mentioned rock sugar syrup, the sterilization temperature is 80° C. to 85° C., and the time is 20 min to 30 min.

[0021] In the preparation method of the rock sugar syrup, the water content of the rock sugar syrup is 35% to 45%.

[0022] The low-acid-reflux, heat-stable rock sugar syrup and its preparation method provided by the present invention have the following beneficial effects compared with the prior art:

[0023] 1. The raw materials of the rock sugar syrup of the present invention contain steviol glycosides and monk fruit extract. Steviol glycosides have good stability and can interfere with the molecular structure of rock sugar, thereby improving the storage stability and thermal stability of the rock sugar syrup and reducing acid reflux. The monk fruit extract contains various water-soluble substances and insoluble substances below 3 kDa, as well as various fermentation enzymatic hydrolysis products, including small molecule peptides, which have antibacterial properties and interfere with the molecular structure of rock sugar, thereby improving the stability of the syrup, reducing the reactivity of the syrup, and significantly improving the storage stability and anti-acid reflux of the rock sugar syrup.

[0024] 2. The raw materials of the rock sugar syrup of the present invention contain maltitol and glucose syrup, which interfere with the crystallization process of rock sugar, hinder the orderly arrangement of rock sugar molecules and the formation of crystal nuclei, and prevent the rock sugar syrup from crystallizing during storage. The addition of steviol glycosides and monk fruit extract in this application can reduce the dosage of maltitol and glucose syrup and achieve good anti-crystallization properties.

[0025] 3. Stevioside and monk fruit extract used in a certain proportion have a good synergistic effect, which effectively solves the instability and acid reflux problems of rock sugar syrup. After fermentation and enzymatic hydrolysis, the monk fruit extract has no interfering odor, can provide good nutritional value, and has good practical value. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to specific implementation cases, but the present invention is not limited to these embodiments.

[0027] Example 1

[0028] The invention discloses a low-acid reflux and heat-stable rock sugar syrup. The rock sugar syrup is prepared from the following raw materials in parts by weight: 85 parts of rock sugar, 0.3 parts of steviol glycosides, 1.2 parts of maltitol, 1.2 parts of glucose syrup, 6 parts of monk fruit extract, 100 parts of purified water and sodium citrate. The pH value of the rock sugar syrup is adjusted to 5.8 by using the sodium citrate.

[0029] The preparation method of the monk fruit extract is as follows: taking the pulp and peel of fresh monk fruit, crushing them to obtain pulp, adding water 9 times the mass of the pulp, adding 2% glucose by mass of the pulp, adding 0.5% Bifidobacterium breve and 0.5% Pediococcus pentosaceus by mass of the pulp, anaerobically fermenting at 37°C for 9 hours, sterilizing at 80°C for 20 minutes, cooling to room temperature, adding 1% ficin by mass of the pulp, enzymolyzing at 65°C for 2.5 hours, inactivating the enzyme at 80°C for 15 minutes, cooling to room temperature, filtering with a 3kDa ultrafiltration membrane to obtain a filtrate below 3kDa, concentrating to 12% of the volume of the filtrate, and obtaining the monk fruit extract.

[0030] The bacterial activity of Bifidobacterium breve was 10 billion CFU / g; the bacterial activity of Pediococcus pentosaceus was 10 billion CFU / g; and the enzymatic activity of ficin was 100,000 U / g.

[0031] The method for preparing the above-mentioned low-acid reflux, heat-stable rock sugar syrup comprises the following steps:

[0032] S1: Boil rock sugar, steviol glycosides, maltitol, glucose syrup and purified water according to their mass ratios to prepare syrup. After the syrup concentration reaches the designed concentration, cool the temperature to 45°C to obtain warm syrup.

[0033] Wherein, the mass concentration of glucose syrup is 50%;

[0034] S2: Adding the Momordica grosvenori extract to the warm syrup, mixing well, adding sodium citrate, adjusting the pH value of the rock sugar syrup to 5.8, filtering, sterilizing at 80° C. for 20 min, and aseptically canning to obtain rock sugar syrup, wherein the water content of the rock sugar syrup is 40%.

[0035] Example 2

[0036] The invention discloses a low-acid reflux and heat-stable rock sugar syrup. The rock sugar syrup is prepared from the following raw materials in parts by mass: 80 parts of glutamic acid, 0.2 parts of steviol glycosides, 0.5 parts of maltitol, 0.5 parts of glucose syrup, 5 parts of monk fruit extract, 80 parts of purified water, and sodium citrate. The pH value of the rock sugar syrup is adjusted to 6.0 by using the sodium citrate.

[0037] The preparation method of the monk fruit extract is as follows: taking the pulp and peel of fresh monk fruit, crushing them to obtain pulp, adding water 8 times the mass of the pulp, adding 1% of glucose by mass of the pulp, adding 0.3% of Bifidobacterium breve and 0.3% of Pediococcus pentosaceus by mass of the pulp, anaerobically fermenting at 36°C for 8 hours, sterilizing at 70°C for 15 minutes, cooling to room temperature, adding 0.5% of ficin by mass of the pulp, enzymolyzing at 60°C for 2 hours, inactivating the enzyme at 70°C for 15 minutes, cooling to room temperature, filtering with a 3kDa ultrafiltration membrane to obtain a filtrate below 3kDa, and concentrating to 10% of the volume of the filtrate to obtain the monk fruit extract.

[0038] The bacterial activity of Bifidobacterium breve was 10 billion CFU / g, the bacterial activity of Pediococcus pentosaceus was 10 billion CFU / g, and the enzymatic activity of ficin was 50,000 U / g.

[0039] The method for preparing the above-mentioned low-acid reflux, heat-stable rock sugar syrup comprises the following steps:

[0040] S1: Boil rock sugar, steviol glycosides, maltitol, glucose syrup and purified water according to their mass ratios to prepare syrup. After the syrup concentration reaches the designed concentration, cool the temperature to 40°C to obtain warm syrup.

[0041] Among them, the mass concentration of glucose syrup is 40%;

[0042] S2: Adding the Momordica grosvenori extract to the warm syrup, mixing well, adding sodium citrate, adjusting the pH value of the rock sugar syrup to 6.0, filtering, sterilizing at 80° C. for 20 min, and aseptically canning to obtain rock sugar syrup, wherein the water content of the rock sugar syrup is 35%.

[0043] Example 3

[0044] The invention discloses a low-acid reflux and heat-stable rock sugar syrup. The rock sugar syrup is prepared from the following raw materials in parts by weight: 82 parts of rock sugar, 0.25 parts of steviol glycosides, 0.8 parts of maltitol, 0.6 parts of glucose syrup, 6 parts of monk fruit extract, 85 parts of purified water, and sodium citrate. The pH value of the rock sugar syrup is adjusted to 5.5 by using the sodium citrate.

[0045] The preparation method of the monk fruit extract is as follows: taking the pulp and peel of fresh monk fruit, crushing them to obtain pulp, adding 8.5 times the mass of water of the pulp, adding 1.5% of glucose of the pulp, adding 0.4% of Bifidobacterium breve and 0.5% of Pediococcus pentosaceus of the pulp, anaerobic fermentation at 36.5°C for 8.5 hours, high temperature sterilization at 75°C for 15 minutes, cooling to room temperature, adding 0.8% of ficin of the pulp mass, enzymolysis at 62°C for 2 hours, high temperature inactivation of enzyme at 85°C for 15 minutes, cooling to room temperature, filtering with a 3kDa ultrafiltration membrane to obtain a filtrate below 3kDa, and concentrating to 12% of the volume of the filtrate to obtain the monk fruit extract.

[0046] The bacterial activity of Bifidobacterium breve was 10 billion CFU / g, the bacterial activity of Pediococcus pentosaceus was 10 billion CFU / g, and the enzymatic activity of ficin was 50,000 U / g.

[0047] The method for preparing the above-mentioned low-acid reflux, heat-stable rock sugar syrup comprises the following steps:

[0048] S1: Boil rock sugar, steviol glycosides, maltitol, glucose syrup and purified water according to their mass ratios to prepare syrup. Measure the syrup concentration to reach the designed concentration and cool it to 42°C to obtain warm syrup.

[0049] Among them, the mass concentration of glucose syrup is 45%;

[0050] S2: adding the monk fruit extract to the warm syrup, mixing evenly, adding sodium citrate, adjusting the pH value of the rock sugar syrup to 5.5, filtering, sterilizing at 82° C. for 20 min, and aseptically canning to obtain rock sugar syrup, wherein the water content of the rock sugar syrup is 38%.

[0051] Example 4

[0052] The invention discloses a low-acid reflux and heat-stable rock sugar syrup. The rock sugar syrup is prepared from the following raw materials in parts by weight: 88 parts of rock sugar, 0.4 parts of steviol glycosides, 1.5 parts of maltitol, 1.5 parts of glucose syrup, 7 parts of monk fruit extract, 110 parts of purified water, and sodium citrate. The pH value of the rock sugar syrup is adjusted to 5.6 by using the sodium citrate.

[0053] The preparation method of the monk fruit extract is as follows: taking the pulp and peel of fresh monk fruit, crushing them to obtain pulp, adding 9.5 times the mass of water of the pulp, adding 2.5% of glucose of the pulp, adding 0.8% of Bifidobacterium breve and 0.8% of Pediococcus pentosaceus of the pulp, anaerobically fermenting at 37.5°C for 9.5h, sterilizing at 82°C for 25min, cooling to room temperature, adding 1.2% of ficin of the pulp mass, enzymolyzing at 68°C for 2.5h, inactivating the enzyme at 82°C for 20min, cooling to room temperature, filtering with a 3kDa ultrafiltration membrane to obtain a filtrate below 3kDa, concentrating to 14% of the volume of the filtrate, and obtaining the monk fruit extract.

[0054] The bacterial activity of Bifidobacterium breve was 10 billion CFU / g, the bacterial activity of Pediococcus pentosaceus was 10 billion CFU / g, and the enzymatic activity of ficin was 100,000 U / g.

[0055] The method for preparing the above-mentioned low-acid reflux, heat-stable rock sugar syrup comprises the following steps:

[0056] S1: Boil rock sugar, steviol glycosides, maltitol, glucose syrup and purified water according to their mass ratios to prepare syrup. After the syrup concentration reaches the designed concentration, cool the temperature to 48°C to obtain warm syrup.

[0057] Among them, the mass concentration of glucose syrup is 55%;

[0058] S2: Adding the Momordica grosvenori extract to the warm syrup, mixing well, adding sodium citrate, adjusting the pH value of the rock sugar syrup to 5.6, filtering, sterilizing at 85° C. for 30 min, and aseptically canning to obtain rock sugar syrup, the water content of the rock sugar syrup being 42%.

[0059] Example 5

[0060] The invention discloses a low-acid reflux and heat-stable rock sugar syrup. The rock sugar syrup is prepared from the following raw materials in parts by weight: 90 parts of rock sugar, 0.35 parts of steviol glycosides, 2 parts of maltitol, 2 parts of glucose syrup, 8 parts of monk fruit extract, 120 parts of purified water, and sodium citrate. The pH value of the rock sugar syrup is adjusted to 6.0 by using the sodium citrate.

[0061] The preparation method of the monk fruit extract is as follows: taking the pulp and peel of fresh monk fruit, crushing them to obtain pulp, adding water 10 times the mass of the pulp, adding 3% of glucose by mass of the pulp, adding 1% of Bifidobacterium breve and 1% of Pediococcus pentosaceus by mass of the pulp, anaerobically fermenting at 38°C for 10 hours, sterilizing at 85°C for 30 minutes, cooling to room temperature, adding 1.5% of ficin by mass of the pulp, enzymolyzing at 70°C for 3 hours, inactivating the enzyme at 85°C for 20 minutes, cooling to room temperature, filtering with a 3kDa ultrafiltration membrane to obtain a filtrate below 3kDa, concentrating to 15% of the volume of the filtrate, and obtaining the monk fruit extract.

[0062] The bacterial activity of Bifidobacterium breve was 10 billion CFU / g, the bacterial activity of Pediococcus pentosaceus was 10 billion CFU / g, and the enzymatic activity of ficin was 100,000 U / g.

[0063] The method for preparing the above-mentioned low-acid reflux, heat-stable rock sugar syrup comprises the following steps:

[0064] S1: Boil rock sugar, steviol glycosides, maltitol, glucose syrup and purified water according to their mass ratios to prepare syrup. After the syrup concentration reaches the designed concentration, cool the temperature to 50°C to obtain warm syrup.

[0065] Among them, the mass concentration of glucose syrup is 60%;

[0066] S2: adding the monk fruit extract to the warm syrup, mixing evenly, adding sodium citrate, adjusting the pH value of the rock sugar syrup to 6.0, filtering, sterilizing at 85° C. for 30 min, and aseptically canning to obtain rock sugar syrup, wherein the water content of the rock sugar syrup is 45%.

[0067] Example 6

[0068] The invention discloses a low-acid reflux and heat-stable rock sugar syrup. The rock sugar syrup is prepared from the following raw materials in parts by weight: 80 parts of rock sugar, 0.25 parts of steviol glycosides, 0.5 parts of maltitol, 2 parts of glucose syrup, 8 parts of monk fruit extract, 80 parts of purified water, and sodium citrate. The pH value of the rock sugar syrup is adjusted to 5.5 by using the sodium citrate.

[0069] The preparation method of the monk fruit extract is as follows: taking the pulp and peel of fresh monk fruit, crushing them to obtain pulp, adding water 10 times the mass of the pulp, adding 1% glucose by mass of the pulp, adding 1% Bifidobacterium breve and 0.3% Pediococcus pentosaceus by mass of the pulp, anaerobically fermenting at 38°C for 8h, sterilizing at 85°C for 15min, cooling to room temperature, adding 1.5% ficin by mass of the pulp, enzymolyzing at 60°C for 3h, inactivating the enzyme at 70°C for 20min, cooling to room temperature, filtering with a 3kDa ultrafiltration membrane to obtain a filtrate below 3kDa, concentrating to 10% of the volume of the filtrate, and obtaining the monk fruit extract.

[0070] The bacterial activity of Bifidobacterium breve was 10 billion CFU / g, the bacterial activity of Pediococcus pentosaceus was 10 billion CFU / g, and the enzymatic activity of ficin was 100,000 U / g.

[0071] The method for preparing the above-mentioned low-acid reflux, heat-stable rock sugar syrup comprises the following steps:

[0072] S1: Boil rock sugar, steviol glycosides, maltitol, glucose syrup and purified water according to their mass ratios to prepare syrup. After the syrup concentration reaches the designed concentration, cool the temperature to 40°C to obtain warm syrup.

[0073] Among them, the mass concentration of glucose syrup is 60%;

[0074] S2: adding the monk fruit extract to the warm syrup, mixing evenly, adding sodium citrate, adjusting the pH value of the rock sugar syrup to 5.5, filtering, sterilizing at 80° C. for 30 min, and aseptically canning to obtain rock sugar syrup, wherein the water content of the rock sugar syrup is 35%.

[0075] Example 7

[0076] The invention discloses a low-acid reflux and heat-stable rock sugar syrup. The rock sugar syrup is prepared from the following raw materials in parts by weight: 90 parts of rock sugar, 0.3 parts of steviol glycosides, 2 parts of maltitol, 0.5 parts of glucose syrup, 5 parts of monk fruit extract, 120 parts of purified water, and sodium citrate. The pH value of the rock sugar syrup is adjusted to 5.7 by using the sodium citrate.

[0077] The preparation method of the monk fruit extract is as follows: taking the pulp and peel of fresh monk fruit, crushing them to obtain pulp, adding water 8 times the mass of the pulp, adding 3% glucose by mass of the pulp, adding 0.3% Bifidobacterium breve and 1% Pediococcus pentosaceus by mass of the pulp, anaerobically fermenting at 36°C for 10 hours, sterilizing at 70°C for 30 minutes, cooling to room temperature, adding 0.5% ficin by mass of the pulp, enzymolyzing at 70°C for 2 hours, inactivating the enzyme at 85°C for 15 minutes, cooling to room temperature, filtering with a 3kDa ultrafiltration membrane to obtain a filtrate below 3kDa, concentrating to 15% of the volume of the filtrate, and obtaining the monk fruit extract.

[0078] The bacterial activity of Bifidobacterium breve was 10 billion CFU / g, the bacterial activity of Pediococcus pentosaceus was 10 billion CFU / g, and the enzymatic activity of ficin was 50,000 U / g.

[0079] The method for preparing the above-mentioned low-acid reflux, heat-stable rock sugar syrup comprises the following steps:

[0080] S1: Boil rock sugar, steviol glycosides, maltitol, glucose syrup and purified water according to their mass ratios to prepare syrup. After the syrup concentration reaches the designed concentration, cool the temperature to 50°C to obtain warm syrup.

[0081] Among them, the mass concentration of glucose syrup is 40%;

[0082] S2: Adding the Momordica grosvenori extract to the warm syrup, mixing well, adding sodium citrate, adjusting the pH value of the rock sugar syrup to 5.7, filtering, sterilizing at 85° C. for 20 min, and aseptically canning to obtain rock sugar syrup, wherein the water content of the rock sugar syrup is 45%.

[0083] Comparative Example 1

[0084] No steviol glycoside is added to the rock sugar syrup, and the steviol glycoside component is replaced by rock sugar; other parameters and methods are the same as in Example 1.

[0085] Comparative Example 2

[0086] No Momordica grosvenori extract was added to the rock sugar syrup, and the components of the Momordica grosvenori extract were replaced by rock sugar; other parameters and methods were the same as those in Example 1.

[0087] Comparative Example 3

[0088] In the preparation method of the Momordica grosvenori extract, fermentation with Bifidobacterium breve and Pediococcus pentosaceus is not performed, and the pulp is directly enzymatically hydrolyzed with ficin; other parameters and methods are the same as those in Example 1.

[0089] Comparative Example 4

[0090] In the preparation method of the Momordica grosvenori extract, ficin hydrolysis is not performed; other parameters and methods are the same as in Example 1.

[0091] Comparative Example 5

[0092] No steviol glycosides and momordica grosvenori extract were added to the rock sugar syrup, and the components of steviol glycosides and momordica grosvenori extract were replaced by rock sugar; other parameters and methods were the same as those in Example 1.

[0093] Experimental tests were performed on the above embodiments and comparative examples.

[0094] 1. Storage stability test

[0095] Take 3 kg of each syrup sample, divide it into three parallel samples, place them in transparent glass bottles, store them at 40°C under light, and cover them for 6 months. Observe the appearance of the syrup and check the pH value after testing.

[0096] The test results are shown in Table 1 below.

[0097] Table 1 Storage stability test results

[0098]

[0099]

[0100] From the above results, it can be seen that in Examples 1 to 7, steviol glycosides and monk fruit extract can improve storage stability, and the combination of steviol glycosides and monk fruit extract has a good synergistic effect. From Comparative Examples 3 and 4, it can be seen that the monk fruit extract with the preparation steps omitted has a significant decline in promoting the storage stability of rock sugar syrup.

[0101] 2. Acid Reflux Test

[0102] The syrups of the embodiments and comparative examples were used to prepare room-temperature milk tea: 5 g of black tea bag, 600 mL of pure milk, 90 mL of rock sugar syrup and 300 mL of water. The water was boiled first, and the black tea bag was added and boiled for 3 minutes. The pure milk was added and stirred evenly. The mixture was continued to boil until slightly boiling. The heat was turned off, the black tea bag was taken out, filtered, cooled to 20°C, rock sugar syrup was added, and stirred evenly to obtain room-temperature milk tea. The pH value of the room-temperature milk tea was measured.

[0103] Hot milk tea was prepared with the syrups of each embodiment and comparative example: 5 g black tea bag, 600 mL pure milk, 90 mL rock sugar syrup and 300 mL water. The water was boiled first, and the black tea bag was added and boiled for 3 minutes. The pure milk was added and stirred evenly. The mixture was continued to boil until slightly boiling, and the rock sugar syrup was added and stirred evenly. The black tea bag was taken out and filtered to obtain hot milk tea. The mixture was cooled to 40°C to obtain hot milk tea, and the pH value of the hot milk tea was measured.

[0104] The test results are shown in Table 2 below.

[0105] Table 2 Acid reflux test results

[0106]

[0107]

[0108] From the above results, it can be seen that the milk teas of Examples 1 to 7 have good anti-acid reflux properties. Stevioside and monk fruit extract can both improve the anti-acid reflux properties. In particular, the rock sugar syrup with the addition of monk fruit extract has a significantly improved anti-acid reflux property. From Comparative Examples 3 and 4, it can be seen that the monk fruit extract, in which the preparation steps are omitted, has a significantly reduced effect on promoting the anti-acid reflux property of the rock sugar syrup.

Claims

1. A low-acid-reflux, heat-stable rock sugar syrup, characterized in that: The rock sugar syrup is prepared from the following raw materials in parts by mass: 80 to 90 parts of rock sugar, 0.2 to 0.4 parts of steviol glycosides, 0.5 to 2 parts of maltitol, 0.5 to 2 parts of glucose syrup, 5 to 8 parts of monk fruit extract, 80 to 120 parts of purified water and sodium citrate, wherein the pH value of the rock sugar syrup is adjusted to 5.5 to 6.0 by using sodium citrate; The preparation method of the monk fruit extract comprises the following steps: taking the pulp and peel of fresh monk fruit, crushing them to obtain pulp, adding water 8 to 10 times the mass of the pulp, adding 1% to 3% of glucose by mass of the pulp, adding 0.3% to 1% of Bifidobacterium breve and 0.3% to 1% of Pediococcus pentosaceus by mass of the pulp, performing anaerobically fermentation at 36 to 38° C. for 8 to 10 hours, sterilizing at high temperature, cooling to room temperature, adding 0.5% to 1.5% of ficin by mass of the pulp, performing enzymatic hydrolysis at 60 to 70° C. for 2 to 3 hours, inactivating the enzyme by high temperature, cooling to room temperature, filtering through a 3 kDa ultrafiltration membrane to obtain a filtrate below 3 kDa, and concentrating to 10% to 15% of the volume of the filtrate to obtain the monk fruit extract; The bacterial activity of the Bifidobacterium breve is 2 to 20 billion CFU / g; the bacterial activity of the Pediococcus pentosaceus is 2 to 20 billion CFU / g; and the enzymatic activity of the ficin is 50,000 to 100,000 U / g.

2. The rock sugar syrup according to claim 1, characterized in that The temperature of the high temperature sterilization is 70° C. to 85° C. and the time is 15 min to 30 min.

3. The rock sugar syrup according to claim 1, characterized in that The temperature of the high temperature enzyme inactivation is 70° C. to 85° C. and the time is 15 min to 20 min.

4. A method for preparing the low-acid-reflux, heat-stable rock sugar syrup according to any one of claims 1 to 3, characterized in that: The steps include: S1: Boil rock sugar, steviol glycosides, maltitol, glucose syrup and purified water according to their mass ratios to prepare syrup. After the syrup concentration reaches the designed concentration, cool the temperature to 40°C to 50°C to obtain warm syrup. S2: adding the monk fruit extract to the warm syrup, mixing evenly, adding sodium citrate, adjusting the pH value of the rock sugar syrup to 5.5-6.0, filtering, sterilizing, and aseptically canning to obtain the rock sugar syrup.

5. The preparation method according to claim 4, characterized in that The mass concentration of the glucose syrup is 40% to 60%.

6. The preparation method according to claim 4, characterized in that The sterilization temperature is 80° C. to 85° C., and the sterilization time is 20 min to 30 min.

7. The preparation method according to claim 4, characterized in that The water content of the rock sugar syrup is 35% to 45%.

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