Grape-flavor beverage thick slurry and preparation method thereof

Abstract

The invention particularly relates to grape flavor beverage thick slurry and a preparation method thereof. The grape flavor beverage thick slurry comprises the following raw materials in parts by weight: 50-70 parts of white granulated sugar, 1-30 parts of grape concentrated juice, 1-4 parts of citric acid, 0.1-0.25 part of a natural preservative, 0.1-1 part of sodium carboxymethyl cellulose, 0.1-1 part of sodium citrate, 1-5 parts of DL-malic acid, 1-4 parts of tartaric acid, 0.1-0.3 part of sucralose and 35-50 parts of water. The grape flavor beverage thick slurry has good nutritional value and appearance, and grapes are natural and pure in taste and long in shelf life; the natural preservative has good compatibility with a concentrated beverage slurry system, has high antibacterial activity, does not contain chemical preservatives, is safe and non-toxic, does not influence the color, aroma and taste of the concentrated beverage slurry, and can stably maintain the natural flavor for a long time. The preparation method of the grape-flavor beverage thick slurry is simple to operate, convenient to control, high in production efficiency and beneficial to industrial production.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a grape-flavored beverage concentrate and its preparation method. Background Technology

[0002] With social development and the improvement of people's living standards, research on high-quality natural flavored beverage concentrates is receiving increasing attention. Grape concentrate is rich in antioxidants and vitamins, which help boost the immune system and promote health. Furthermore, grape concentrate has a rich flavor and complex texture. Adding grape concentrate to beverage concentrates not only enhances the grape flavor but also improves the overall taste. However, traditional beverage concentrates are easily contaminated by mold, yeast, or other microorganisms during production, resulting in substandard hygiene standards and short shelf lives. Therefore, preservatives are often added for preservation and antibacterial purposes. However, existing chemical preservatives can have certain toxic side effects on the human body, which remains to be addressed. Summary of the Invention

[0003] To overcome the shortcomings and deficiencies of existing technologies, the present invention aims to provide a grape-flavored beverage concentrate and its preparation method. The grape-flavored beverage concentrate is prepared by compounding raw materials such as white sugar, grape concentrate, and citric acid, and adding natural preservatives. This results in a grape-flavored beverage concentrate with good nutritional value and sensory appeal, a pure grape taste, a long shelf life, and the ability to stably maintain its natural flavor over a long period. The preparation method of the grape-flavored beverage concentrate is simple to operate, easy to control, and has high production efficiency, making it suitable for industrial production.

[0004] The objective of this invention is achieved through the following technical solution: a grape-flavored beverage concentrate, comprising the following raw materials in parts by weight: 50-70 parts white sugar, 1-30 parts grape concentrate, 1-4 parts citric acid, 0.1-0.25 parts natural preservative, 0.1-1 parts sodium carboxymethyl cellulose, 0.1-1 parts sodium citrate, 1-5 parts DL-malic acid, 1-4 parts tartaric acid, and 0.1-0.3 parts sucralose.

[0005] Furthermore, the grape-flavored beverage concentrate comprises the following ingredients in parts by weight: 50-70 parts white sugar, 20-30 parts grape concentrate, 1-4 parts citric acid, 0.1-0.25 parts natural preservative, 0.1-1 parts sodium carboxymethyl cellulose, 0.1-1 parts sodium citrate, 1-5 parts DL-malic acid, 1-4 parts tartaric acid, and 0.1-0.3 parts sucralose.

[0006] Furthermore, the grape-flavored beverage concentrate also includes 0.01-1 parts of pigment; at least one of brilliant blue, amaranth, carmine, tartrazine, and caramel color, wherein the sum of the weight parts of brilliant blue, amaranth, carmine, and tartrazine in the pigment is not greater than 0.1 parts.

[0007] Furthermore, each part of the natural preservative includes the following ingredients in parts by weight: 4-8 parts of nisin, 5-10 parts of ε-polylysine hydrochloride, and 10-15 parts of a compound extract of olive leaf and plum.

[0008] Furthermore, the compound extract of olive leaves and dried plum is formed by mixing olive leaf extract and dried plum extract and then drying them, wherein the mass ratio of olive leaf extract to dried plum extract is 1:0.8-1.2.

[0009] Furthermore, the preparation method of the compound extract of olive leaves and dried plum includes the following steps: reducing the temperature of the cold trap of the vacuum freeze-drying equipment to -40℃ to -50℃ within 2-3 hours, and maintaining this temperature for 40-90 minutes.

[0010] Furthermore, the preparation method of the olive leaf extract includes the following steps:

[0011] (A1) Take dried olive leaves, crush them, add them to water and mix well; add compound enzyme to the mixture and stir well, then inactivate the enzyme after enzymatic hydrolysis to obtain the enzymatic hydrolysate;

[0012] (A2) Add an ethanol-water solution to the enzymatic hydrolysate, extract using ultrasound, filter the resulting extract through a filter membrane, concentrate the filtrate under reduced pressure to obtain olive leaf extract.

[0013] Furthermore, in step (A1), the enzymatic hydrolysis temperature is 36-39℃, and the enzymatic hydrolysis time is 30-60 min; each portion of the compound enzyme, by weight, includes 1-2 parts of cellulase, 1-2 parts of pectinase, 1-2 parts of xylanase, 0.5-1 parts of mannanase, and 0.5-1 parts of β-glucanase; the amount of the compound enzyme added is 0.4-0.8 wt% of the total amount of olive leaves.

[0014] By adding the above-mentioned compound enzyme, this invention can selectively enzymatically hydrolyze the cellulose and hemicellulose components of olive leaf cell walls. After enzymatic hydrolysis, ultrasonic treatment is performed, which helps to improve the yield of bioactive substances in olive leaf cell walls and enhance the antibacterial activity, antioxidant properties, and nutritional value of natural preservatives.

[0015] Furthermore, in step (A1), the liquid-to-solid ratio of water to water is 8-12:1 (mL / g).

[0016] Furthermore, in step (A2), the concentration of the ethanol-water solution is 60-70 wt%, the ultrasonic treatment power is 300-400 W, the treatment time is 5-10 min, and the liquid-to-solid ratio is 6-10:1 (mL / g); the extract is filtered through a 0.22 μm filter membrane and then concentrated under reduced pressure to 1 / 2-1 / 3 of its original volume.

[0017] Furthermore, the preparation method of the plum extract includes the following steps: the dried and pitted plum extract is pulverized and passed through a 50-mesh sieve, added to an ethanol aqueous solution for ultrasonic treatment, and after extraction, the obtained extract is centrifuged and filtered, and the supernatant is concentrated under reduced pressure to obtain the plum extract.

[0018] Furthermore, in the preparation method of the plum extract, the concentration of the ethanol aqueous solution is 60-70wt%, the ultrasonic treatment power is 300-400W, the treatment time is 30-40min, and the liquid-to-solid ratio is 10-14:1 (mL / g); the obtained supernatant is concentrated under reduced pressure to 1 / 2-1 / 3 of the original volume to obtain the plum extract.

[0019] The present invention also provides a method for preparing the above-mentioned grape-flavored beverage concentrate, comprising the following steps:

[0020] (1) By weight, take a portion of white sugar and carboxymethyl cellulose and dry mix them, add a portion of water, then heat, and continue to add the remaining white sugar. After the white sugar dissolves, homogenize it on a homogenizer until the sodium carboxymethyl cellulose is completely dissolved into a transparent, particle-free solution to obtain a homogenized sugar solution.

[0021] (2) Prepare aqueous solutions of natural preservative, sodium citrate, citric acid, DL-malic acid, tartaric acid and sucralose respectively, and set aside for use;

[0022] (3) Add grape concentrate and sucralose solution to the sugar solution obtained in step (1); then heat the sugar solution with sodium citrate solution, citric acid solution, DL-malic acid solution and tartaric acid solution, and keep it warm after heating.

[0023] (4) After the sugar solution obtained in step (3) is kept warm, it is cooled and then the remaining water and natural preservatives are added, or the remaining water, pigments and natural preservatives are added to obtain grape flavored beverage concentrate.

[0024] Furthermore, in step (1), the heating temperature is 80-90℃.

[0025] Furthermore, in step (3), the sugar solution is heated to 85-90℃ and kept warm for 10-30 minutes.

[0026] Furthermore, in step (4), the sugar solution is cooled to 45-50°C.

[0027] The beneficial effects of this invention are as follows: The grape-flavored beverage concentrate of this invention is prepared by compounding raw materials such as white sugar, grape concentrate, and citric acid, and adding natural preservatives. This results in a grape-flavored beverage concentrate with good nutritional value and sensory appeal, a naturally pure grape taste, and a long shelf life. The added natural preservatives have good compatibility with the beverage concentrate system, high antibacterial activity, and are free of chemical preservatives, making them safe and non-toxic. When added to the flavored beverage concentrate, they effectively exert a preservative effect without affecting the color, aroma, and flavor of the beverage concentrate, and can stably maintain the natural flavor for a long time. The preparation method of the grape-flavored beverage concentrate is simple to operate, easy to control, and has high production efficiency, which is conducive to industrial production. The resulting product has stable quality and is safe for consumption. Detailed Implementation

[0028] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments. The content mentioned in the embodiments is not intended to limit the present invention.

[0029] In some embodiments of the present invention, a grape-flavored beverage concentrate comprises the following ingredients in parts by weight: 50-70 parts white sugar, 1-30 parts grape concentrate, 1-4 parts citric acid, 0.1-0.25 parts natural preservative, 0.1-1 parts sodium carboxymethyl cellulose, 0.1-1 parts sodium citrate, 1-5 parts DL-malic acid, 1-4 parts tartaric acid, and 0.1-0.3 parts sucralose.

[0030] In some embodiments of the present invention, the grape-flavored beverage concentrate comprises the following raw materials in parts by weight: 50-70 parts white sugar, 20-30 parts grape concentrate, 1-4 parts citric acid, 0.1-0.25 parts natural preservative, 0.1-1 parts sodium carboxymethyl cellulose, 0.1-1 parts sodium citrate, 1-5 parts DL-malic acid, 1-4 parts tartaric acid, and 0.1-0.3 parts sucralose.

[0031] In some embodiments of the present invention, the grape-flavored beverage concentrate further includes 0.01-1 parts of pigment; at least one of brilliant blue, amaranth, carmine, tartrazine, and caramel color, wherein the sum of the weight parts of brilliant blue, amaranth, carmine, and tartrazine in the pigment is not greater than 0.1 parts.

[0032] In some embodiments of the present invention, each part of the natural preservative comprises the following raw materials in parts by weight: 4-8 parts of nisin, 5-10 parts of ε-polylysine hydrochloride, and 10-15 parts of a compound extract of olive leaves and dried plum.

[0033] Example 1

[0034] In this embodiment, a grape-flavored beverage concentrate comprises the following ingredients in parts by weight: 60 parts white sugar, 20 parts grape concentrate, 2 parts citric acid, 0.2 parts natural preservative, 0.4 parts sodium carboxymethyl cellulose, 0.4 parts sodium citrate, 3 parts DL-malic acid, 3 parts tartaric acid, 0.2 parts sucralose, 0.00013 parts brilliant blue, 0.0009 parts amaranth, 0.0032 parts carmine, and 0.08 parts caramel color.

[0035] Furthermore, each serving of the natural preservative includes the following ingredients in parts by weight: 6 parts nisin, 8 parts ε-polylysine hydrochloride, and 12 parts a compound extract of olive leaf and plum.

[0036] Furthermore, the compound extract of olive leaves and dried plum is formed by mixing olive leaf extract and dried plum extract and then drying them, wherein the olive leaf extract and dried plum extract are used in a mass ratio of 1:1.

[0037] Furthermore, the preparation method of the compound extract of olive leaves and dried plum includes the following steps: reducing the temperature of the cold trap of the vacuum freeze-drying equipment to -45°C within 2.5 hours and maintaining it at that temperature for 60 minutes.

[0038] Furthermore, the preparation method of the olive leaf extract includes the following steps:

[0039] (A1) Take dried olive leaves, crush them, add them to water and mix them evenly. The liquid-to-solid ratio is 10:1 (mL / g). Add a compound enzyme to the mixture and stir evenly. After enzymatic hydrolysis, the enzyme is inactivated to obtain an enzymatic hydrolysate. The amount of the compound enzyme added is 0.6 wt% of the total amount of olive leaves.

[0040] (A2) Add an ethanol-water solution to the enzymatic hydrolysate, extract using ultrasound, filter the resulting extract through a filter membrane, concentrate the filtrate under reduced pressure to obtain olive leaf extract.

[0041] Furthermore, in step (A1), the enzymatic hydrolysis temperature is 37°C and the enzymatic hydrolysis time is 50 min; each part of the compound enzyme, by weight, includes 1.5 parts of cellulase, 1.5 parts of pectinase, 1.5 parts of xylanase, 0.8 parts of mannanase and 0.8 parts of β-glucanase.

[0042] Furthermore, in step (A2), the concentration of the ethanol-water solution is 65 wt%, the ultrasonic treatment power is 350 W, the treatment time is 8 min, and the liquid-to-solid ratio is 8:1 (mL / g); the extract is filtered through a 0.22 μm filter membrane and then concentrated under reduced pressure to 1 / 3 of its original volume.

[0043] Furthermore, the preparation method of the plum extract includes the following steps: the dried and pitted plum extract is pulverized and passed through a 50-mesh sieve, added to an ethanol aqueous solution for ultrasonic treatment, the concentration of the ethanol aqueous solution is 65wt%, the ultrasonic treatment power is 350W, the treatment time is 35min, and the liquid-to-solid ratio is 12:1 (mL / g); after the extraction is completed, the obtained extract is centrifuged and filtered, and the supernatant obtained is concentrated under reduced pressure to 1 / 3 of the original volume to obtain the plum extract.

[0044] The present invention also provides a method for preparing the above-mentioned grape-flavored beverage concentrate, comprising the following steps:

[0045] (1) By weight, take 1 / 2 of the white sugar and carboxymethyl cellulose and dry mix them. Add 2 / 3 of the water and heat to 85°C. Continue to add the remaining white sugar. After the white sugar dissolves, homogenize it in a homogenizer until the sodium carboxymethyl cellulose is completely dissolved into a transparent, particle-free solution.

[0046] (2) Prepare aqueous solutions of natural preservative, sodium citrate, citric acid, DL-malic acid, tartaric acid and sucralose respectively, and set aside for use;

[0047] (3) Add grape concentrate and sucralose solution to the sugar solution obtained in step (1); then add sodium citrate solution, citric acid solution, DL-malic acid solution and tartaric acid solution to heat the sugar solution to 86°C and keep it warm for 20 minutes.

[0048] (4) After the sugar solution obtained in step (3) is kept warm, it is cooled to 48°C, and then the remaining water, pigment and natural preservative are added. The pigment is pre-mixed with water to prepare an aqueous solution, and the grape flavored beverage concentrate is obtained.

[0049] Example 2

[0050] In this embodiment, a grape-flavored beverage concentrate comprises the following ingredients in parts by weight: 50 parts white sugar, 20 parts grape concentrate, 2 parts citric acid, 0.1 parts natural preservative, 0.1 parts sodium carboxymethyl cellulose, 0.1 parts sodium citrate, 2 parts DL-malic acid, 2 parts tartaric acid, 0.1 parts sucralose, 0.0001 parts brilliant blue, 0.0008 parts amaranth, 0.003 parts carmine, and 0.06 parts caramel color.

[0051] Furthermore, each serving of the natural preservative includes the following ingredients in parts by weight: 4 parts nisin, 5 parts ε-polylysine hydrochloride, and 10 parts a compound extract of olive leaf and plum.

[0052] Furthermore, the compound extract of olive leaves and dried plum is formed by mixing olive leaf extract and dried plum extract and then drying them, wherein the olive leaf extract and dried plum extract are used in a mass ratio of 1:0.8.

[0053] Furthermore, the preparation method of the compound extract of olive leaves and dried plum includes the following steps: reducing the temperature of the cold trap of the vacuum freeze-drying equipment to -40°C within 2 hours and maintaining it at that temperature for 90 minutes.

[0054] Furthermore, the preparation method of the olive leaf extract includes the following steps:

[0055] (A1) Take dried olive leaves, crush them, add them to water and mix them evenly. The liquid-to-solid ratio is 12:1 (mL / g). Add the compound enzyme to the mixture and stir evenly. After enzymatic hydrolysis, the enzyme is inactivated to obtain the enzymatic hydrolysate. The amount of the compound enzyme added is 0.5 wt% of the total amount of olive leaves.

[0056] (A2) Add an ethanol-water solution to the enzymatic hydrolysate, extract using ultrasound, filter the resulting extract through a filter membrane, concentrate the filtrate under reduced pressure to obtain olive leaf extract.

[0057] Furthermore, in step (A1), the enzymatic hydrolysis temperature is 36°C and the enzymatic hydrolysis time is 60 min; each part of the compound enzyme, by weight, includes 2 parts of cellulase, 1 part of pectinase, 1 part of xylanase, 0.1 parts of mannanase and 0.5 parts of β-glucanase.

[0058] Furthermore, in step (A2), the concentration of the ethanol-water solution is 65wt%, the ultrasonic treatment power is 300W, the treatment time is 5-10min, and the liquid-to-solid ratio is 6:1 (mL / g); the extract is filtered through a 0.22μm filter membrane and then concentrated under reduced pressure to half of its original volume.

[0059] Furthermore, the preparation method of the plum extract includes the following steps: the dried and pitted plum extract is pulverized and passed through a 50-mesh sieve, added to an ethanol aqueous solution for ultrasonic treatment, the concentration of the ethanol aqueous solution is 65wt%, the ultrasonic treatment power is 300W, the treatment time is 40min, and the liquid-to-solid ratio is 10:1 (mL / g); after the extraction is completed, the obtained extract is centrifuged and filtered, and the supernatant is concentrated under reduced pressure to 1 / 2-1 / 3 of the original volume to obtain the plum extract.

[0060] The present invention also provides a method for preparing the above-mentioned grape-flavored beverage concentrate, comprising the following steps:

[0061] (1) By weight, take 1 / 2 of the white sugar and carboxymethyl cellulose and dry mix them. Add some water and heat to 80°C. Continue to add the remaining white sugar. After the white sugar dissolves, homogenize it in a homogenizer until the sodium carboxymethyl cellulose is completely dissolved into a transparent, particle-free solution.

[0062] (2) Prepare aqueous solutions of natural preservative, sodium citrate, citric acid, DL-malic acid, tartaric acid and sucralose respectively, and set aside for use;

[0063] (3) Add grape concentrate and sucralose solution to the sugar solution obtained in step (1); then add sodium citrate solution, citric acid solution, DL-malic acid solution and tartaric acid solution to heat the sugar solution to 85°C and keep it warm for 30 minutes.

[0064] (4) After the sugar solution obtained in step (3) is kept warm, it is cooled to 50°C, and then the remaining water, pigment and natural preservative are added to obtain grape flavored beverage concentrate.

[0065] The rest of this embodiment is the same as that in Embodiment 1.

[0066] Example 3

[0067] In this embodiment, a grape-flavored beverage concentrate comprises the following ingredients in parts by weight: 70 parts white sugar, 30 parts grape concentrate, 4 parts citric acid, 0.25 parts natural preservative, 1 part sodium carboxymethyl cellulose, 1 part sodium citrate, 5 parts DL-malic acid, 4 parts tartaric acid, 0.3 parts sucralose, 0.0001 parts brilliant blue, 0.0008 parts amaranth, 0.003 parts carmine, and 0.06 parts caramel color.

[0068] Furthermore, each serving of the natural preservative includes the following ingredients in parts by weight: 8 parts nisin, 10 parts ε-polylysine hydrochloride, and 15 parts a compound extract of olive leaf and plum.

[0069] Furthermore, the compound extract of olive leaves and dried plum is formed by mixing olive leaf extract and dried plum extract and then drying them, wherein the olive leaf extract and dried plum extract are used in a mass ratio of 1:1.2.

[0070] Furthermore, the preparation method of the compound extract of olive leaves and dried plum includes the following steps: reducing the temperature of the cold trap of the vacuum freeze-drying equipment to -50°C within 2-3 hours and maintaining it at this temperature for 40 minutes.

[0071] Furthermore, the preparation method of the olive leaf extract includes the following steps:

[0072] (A1) Take dried olive leaves, crush them, add them to water and mix them evenly. The liquid-to-solid ratio is 12:1 (mL / g). Add a compound enzyme to the mixture and stir evenly. After enzymatic hydrolysis, the enzyme is inactivated to obtain an enzymatic hydrolysate. The amount of the compound enzyme added is 0.8 wt% of the total amount of olive leaves.

[0073] (A2) Add an ethanol-water solution to the enzymatic hydrolysate, extract using ultrasound, filter the resulting extract through a filter membrane, concentrate the filtrate under reduced pressure to obtain olive leaf extract.

[0074] Furthermore, in step (A1), the enzymatic hydrolysis temperature is 39°C and the enzymatic hydrolysis time is 30 min; each part of the compound enzyme, by weight, includes 2 parts of cellulase, 2 parts of pectinase, 1 part of xylanase, 1 part of mannanase and 1 part of β-glucanase.

[0075] Furthermore, in step (A2), the concentration of the ethanol-water solution is 65 wt%, the ultrasonic treatment power is 400 W, the treatment time is 5 min, and the liquid-to-solid ratio is 10:1 (mL / g); the extract is filtered through a 0.22 μm filter membrane and then concentrated under reduced pressure to 1 / 3 of its original volume.

[0076] Furthermore, the preparation method of the plum extract includes the following steps: the dried and pitted plum extract is pulverized and passed through a 50-mesh sieve, added to an ethanol aqueous solution for ultrasonic treatment, the concentration of the ethanol aqueous solution is 65wt%, the ultrasonic treatment power is 400W, the treatment time is 30min, and the liquid-to-solid ratio is 14:1 (mL / g); after the extraction is completed, the obtained extract is centrifuged and filtered, and the supernatant obtained is concentrated under reduced pressure to 1 / 3 of the original volume to obtain the plum extract.

[0077] The present invention also provides a method for preparing the above-mentioned grape-flavored beverage concentrate, comprising the following steps:

[0078] (1) By weight, take 1 / 2 of the white sugar and carboxymethyl cellulose and dry mix them. Add some water and heat to 85°C. Continue to add the remaining white sugar. After the white sugar dissolves, homogenize it in a homogenizer until the sodium carboxymethyl cellulose is completely dissolved into a transparent, particle-free solution.

[0079] (2) Prepare aqueous solutions of natural preservative, sodium citrate, citric acid, DL-malic acid, tartaric acid and sucralose respectively, and set aside for use;

[0080] (3) Add grape concentrate and sucralose solution to the sugar solution obtained in step (1); then add sodium citrate solution, citric acid solution, DL-malic acid solution and tartaric acid solution to heat the sugar solution to 86°C and keep it warm for 30 minutes.

[0081] (4) After the sugar solution obtained in step (3) is kept warm, it is cooled to 50°C, and then the remaining water, pigment and natural preservative are added to obtain grape flavored beverage concentrate.

[0082] The rest of this embodiment is the same as that in Embodiment 1.

[0083] Example 4

[0084] In this embodiment, the grape-flavored beverage concentrate comprises the following ingredients in parts by weight: 65 parts white sugar, 22 parts grape concentrate, 3 parts citric acid, 0.15 parts natural preservative, 0.3 parts sodium carboxymethyl cellulose, 0.3 parts sodium citrate, 3 parts DL-malic acid, 2 parts tartaric acid, and 0.15 parts sucralose.

[0085] The rest of this embodiment is the same as that in Embodiment 1.

[0086] Comparative Example 1

[0087] The difference between this comparative example and Example 1 is that the preparation method of the olive leaf extract includes the following steps:

[0088] The dried olive leaves were crushed and added to an ethanol-water solution with a concentration of 65 wt%. The solution was then subjected to ultrasonic treatment at a power of 350 W for 20 min, with a liquid-to-solid ratio of 10:1 (mL / g). The resulting extract was then filtered through a 0.22 μm filter membrane and concentrated under reduced pressure to one-third of its original volume to obtain the olive leaf extract.

[0089] Comparative Example 2

[0090] The difference between this comparative example and Example 1 is that an equal amount of potassium sorbate is used to replace the olive leaf and plum compound extract.

[0091] Comparative Example 3

[0092] The difference between this comparative example and Example 1 is that an equal amount of potassium sorbate is used to replace the natural preservative.

[0093] The natural preservatives in Examples 1-4 were subjected to oral toxicity tests according to standard GB15193.13-2015 "90-day oral toxicity test". The tests showed that the natural preservatives were all safe and could be used as food additives when used in reasonable amounts.

[0094] The olive leaf extracts obtained in Example 1 and Comparative Example 1 were freeze-dried and then dried to obtain crude olive leaf polysaccharide powder. The dosages used in the experiments were calculated based on air-dried powder. The extraction rate of crude olive leaf polysaccharide was calculated as (mass of freeze-dried powder / mass of olive leaf powder sample) * 100%. The extraction rate in Example 1 was 15.7%, and the extraction rate in Comparative Example 1 was 12.1%. Therefore, the extraction method of the olive leaf extract of the present invention, by combining ultrasonic extraction with enzymatic hydrolysis, helps to improve the yield of active substances in olive leaves. Adding it to natural preservatives and beverage concentrates helps to improve antioxidant and antibacterial activity.

[0095] The flavored beverage concentrates of Examples 1-4 and Comparative Examples 2-3 were tested for odor, taste, and color. Test methods for odor, taste, and color: 200g of beverage concentrate was placed in a sealed container at 25℃ for 35 days. Then, its color was observed, its odor was smelled, and the beverage concentrate was tasted.

[0096]

[0097] Prepare beverage concentrate samples according to the formula. Using the methods in GB / T4789.2-2022 "National Food Safety Standard - Microbiological Examination of Food: Determination of Total Colony Count", GB4789.3-2025 "National Food Safety Standard - Microbiological Examination of Food: Coliform Count", and GB4789.15-2016 "National Food Safety Standard - Microbiological Examination of Food: Mold and Yeast Count", under storage conditions of 27℃, the growth rate (%) of coliform and mold counts in the samples was calculated at 0 and 50 days. The growth rate (%) was calculated as follows: (50-day colony count - 0-day colony count) / 0-day colony count * 100%. The test results are shown in the table below.

[0098]

[0099]

[0100] The grape-flavored beverage concentrate prepared by this invention has good nutritional value and sensory appeal, with a pure grape taste and a long shelf life. The added natural preservatives are compatible with the beverage concentrate system, have high antibacterial activity, and are free of chemical preservatives, making them safe and non-toxic. When added to the flavored beverage concentrate, they can play a good preservative role without affecting the color, aroma, and flavor of the beverage concentrate, and can maintain the natural flavor stably for a long time.

[0101] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A grape-flavored beverage concentrate, characterized in that: The ingredients include the following parts by weight: 50-70 parts white sugar, 1-30 parts grape concentrate, 1-4 parts citric acid, 0.1-0.25 parts natural preservative, 0.1-1 part sodium carboxymethyl cellulose, 0.1-1 part sodium citrate, 1-5 parts DL-malic acid, 1-4 parts tartaric acid, 0.1-0.3 parts sucralose, and 35-50 parts water.

2. The flavored beverage concentrate according to claim 1, characterized in that: It also includes 0.01-1 parts of pigment; at least one of the following: brilliant blue, amaranth, carmine, lemon yellow and caramel color, wherein the sum of the weight parts of the pigments brilliant blue, amaranth, carmine and lemon yellow is not greater than 0.1 parts.

3. The flavored beverage concentrate according to claim 1, characterized in that: Each serving of natural preservative contains the following ingredients by weight: 4-8 parts nisin, 5-10 parts ε-polylysine hydrochloride, and 10-15 parts a compound extract of olive leaf and plum.

4. The flavored beverage concentrate according to claim 3, characterized in that: The compound extract of olive leaves and dried plum is formed by mixing olive leaf extract and dried plum extract and then drying them. The mass ratio of olive leaf extract to dried plum extract used in the olive leaf extract is 1:0.8-1.

2.

5. The flavored beverage concentrate according to claim 4, characterized in that: The preparation method of the olive leaf extract includes the following steps: (A1) Take dried olive leaves, crush them, add them to water and mix well; add compound enzyme to the mixture and stir well, then inactivate the enzyme after enzymatic hydrolysis to obtain the enzymatic hydrolysate; (A2) Add an ethanol-water solution to the enzymatic hydrolysate, extract using ultrasound, filter the resulting extract through a filter membrane, and concentrate under reduced pressure to obtain olive leaf extract.

6. The flavored beverage concentrate according to claim 4, characterized in that: In step (A2), the ultrasonic treatment power is 300-400W, the treatment time is 5-10min, and the liquid-to-material ratio is 6-10:1 (mL / g).

7. A method for preparing grape-flavored beverage concentrate as described in any one of claims 1-6, characterized in that: The preparation method of the grape-flavored beverage concentrate includes the following steps: (1) By weight, take a portion of white sugar and carboxymethyl cellulose and dry mix them, add a portion of water, then heat, and continue to add the remaining white sugar. After the white sugar dissolves, homogenize it on a homogenizer until the sodium carboxymethyl cellulose is completely dissolved into a transparent, particle-free solution to obtain a homogenized sugar solution. (2) Prepare aqueous solutions of sodium citrate, citric acid, DL-malic acid, tartaric acid and sucralose respectively, and set aside for later use; (3) Add grape concentrate and sucralose solution to the sugar solution obtained in step (1); then heat the sugar solution with sodium citrate solution, citric acid solution, DL-malic acid solution and tartaric acid solution, and keep it warm after heating. (4) After the sugar solution obtained in step (3) is kept warm, it is cooled and then the remaining water and natural preservatives are added, or the remaining water, pigments and natural preservatives are added to obtain grape flavored beverage concentrate.

8. The grape-flavored beverage concentrate according to claim 7, characterized in that: In step (1), the heating temperature is 80-90℃.

9. The grape-flavored beverage concentrate according to claim 7, characterized in that: In step (3), the sugar solution is heated to 85-90℃ and kept warm for 10-30 minutes.

10. The grape-flavored beverage concentrate according to claim 7, characterized in that: In step (4), the sugar solution is cooled to 45-50°C.

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