Recovery of natural pigments in plant-based beverages after heat treatment
By using a combination of less refined proteins, antioxidants, and chelating agents, along with homogenization and shearing treatment, the problem of red beetroot color degradation in plant-based beverages was solved, achieving the restoration of red hues and improved stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SOCIETE DES PRODUITS NESTLE SA
- Filing Date
- 2024-08-16
- Publication Date
- 2026-04-10
AI Technical Summary
In existing technologies, the color of red beetroot in plant-based beverages is easily degraded after heat treatment, causing the color to change from natural red to orange/brown. Furthermore, existing methods are costly and have low consumer familiarity.
Using a combination of less refined proteins, antioxidants, and chelating agents, the red color of red beetroot is restored through homogenization and shearing. The specific steps include dissolving the plant protein source, adding red beet extract, homogenization and heat treatment, and shearing.
After pasteurization and UHT treatment, the red hue is effectively restored, the orange hue is reduced, and the color stability and consumer acceptance are improved.
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Abstract
Description
Background Technology
[0001] Currently, methods for producing red in plant-based beverages primarily involve using artificial reds, such as carmine, Allura Red AC, and red acid dyes, or using oil-soluble carotenoids, such as beta-carotene and lycopene. Artificial reds can produce a stable red color in products, but are unpopular with consumers due to concerns about side effects such as hyperactivity and the development of mild allergies. The use of carotenoids for red production is also limited by the fact that they turn orange upon heat treatment.
[0002] Natural extracts from beetroot have been proposed as a natural red colorant for plant-based meat substitutes. However, beetroot color is known to degrade upon heating. The thermal degradation of beetroot occurs at the typical high temperatures of the preheater and insulation tubes of UHT processors, which are required to make plant-based ready-to-drink beverages microbiologically safe for consumption. The thermal degradation of beetroot alters the product's color by decreasing the intensity of the positive a value (red hue) and increasing the intensity of the positive b value (yellow hue) on a laboratory color scale. This results in a net change from a natural red to orange / brown.
[0003] A possible explanation for the color loss and regeneration is that betaine (the molecule responsible for the red color of beetroot) undergoes hydrolysis due to the milk's pH being above 6 and heat treatment. The hydrolysis of betaine is reversible after short-term heat treatment, and the regeneration rate improves when stored at temperatures below 10°C. The regeneration of betaine after hydrolysis is pH-dependent; the reaction is favorable at pH 6 in the absence of oxygen, while no pigment recondensation was observed at pH 7.
[0004] Chinese patent CN111067009 outlines a method for improving the thermal stability of beet red pigment via a complex combination of hydrocolloids, antioxidants, and cyclodextrins. This complex combination has several drawbacks, including high cost, low consumer familiarity, and increased product viscosity.
[0005] Therefore, new solutions are needed to prevent the color degradation of red beetroot in pasteurized and UHT-treated plant-based ready-to-drink beverages. Summary of the Invention
[0006] This invention utilizes a combination of less refined proteins, antioxidants, and chelating agents to restore the red color of beet-based RTD plant-based beverages. Specifically, color restoration focuses on the reduction in positive b-value during the first two weeks of shelf life, effectively eliminating orange. This loss of orange hue after UHT treatment is key to red restoration. Additionally, the addition of sodium ascorbate appears to increase the rate of red regeneration.
[0007] Embodiments of the present invention
[0008] The present invention relates to a method for preparing a plant-based liquid, the method comprising dissolving a plant protein source in water to form a plant protein mixture; adding red beet extract to the plant protein mixture; dispersing an oil in the plant protein mixture; homogenizing the plant protein mixture to form an emulsion; applying a heat treatment to the emulsion; and applying a shear treatment to the heat-treated emulsion to form a plant-based liquid.
[0009] The present invention further relates to a method for preparing a plant-based liquid, the method comprising dissolving a plant protein source in water to form a plant protein mixture; adding a powdered or liquid red beet extract to the plant protein mixture; dispersing an oil in the plant protein mixture; homogenizing the plant protein mixture to form an emulsion; subjecting the emulsion to heat treatment; and subjecting the heat-treated emulsion to shear treatment to form a plant-based liquid.
[0010] The present invention further relates to a method for preparing a plant-based liquid, the method comprising:
[0011] a. Dissolve plant protein sources in water to form a plant protein mixture;
[0012] b. Add red beet extract, either in powder or liquid form, to the plant protein mixture;
[0013] c. Optionally, the plant protein mixture is incubated together with the enzyme;
[0014] d. Optionally, add a hydrocolloid to the plant protein mixture;
[0015] e. Disperse the oil in the plant protein mixture;
[0016] f. Homogenize the plant protein mixture to form an emulsion;
[0017] g. Applying heat treatment to the emulsion; and
[0018] h. Applying shear treatment to the heat-treated emulsion to form a plant-based liquid.
[0019] The present invention further relates to a method for preparing a plant-based liquid, the method comprising:
[0020] a. Dissolve the plant protein source in water to form a plant protein mixture with a pH of 6.5 or higher;
[0021] b. At a pH greater than 6, add powdered or liquid red beet extract to the plant protein mixture and stir to dissolve;
[0022] c. Optionally, the plant protein mixture is incubated together with the enzyme;
[0023] d. Optionally, add a hydrocolloid to the plant protein mixture;
[0024] e. Disperse the oil in the plant protein mixture;
[0025] f. Homogenize the plant protein mixture to form an emulsion;
[0026] g. Applying heat treatment to the emulsion; and
[0027] h. Applying shear treatment to the heat-treated emulsion to form a plant-based liquid.
[0028] In some implementations, sodium ascorbate is dissolved in the plant protein mixture before or during step e).
[0029] In some implementations, sodium ascorbate and citric acid are dissolved in the plant protein mixture before or during step e).
[0030] In some implementations, the plant protein source is derived from legumes, such as red beans, adzuki beans, kidney beans, peas, fava beans, chickpeas, or lentils.
[0031] In some implementations, the calcium source is dissolved in a mixture of plant proteins.
[0032] In some implementations, the sugar is dissolved in a mixture of plant proteins.
[0033] In some implementations, the calcium source includes tricalcium phosphate, calcium citrate, or calcium carbonate.
[0034] In some implementations, the plant protein mixture is adjusted to a pH between 6.5 and 8 before incubation with the enzyme.
[0035] In some implementations, the enzymes are amylases and glycoside hydrolases.
[0036] In some implementations, a two-stage high-pressure homogenizer is used to form the emulsion.
[0037] In some implementations, the average particle size of the emulsion is less than 1 mm, as measured by laser diffraction.
[0038] In some implementations, the viscosity of the plant-based liquid is 12.7 s. -1 The pressure is less than 75 mPa·s.
[0039] In some implementations, the plant-based liquid contains less than 0.5% starch.
[0040] In some embodiments, the plant-based liquid has an A value >10 and a hue angle between 330° and 30°, preferably 345° and 15°, and more preferably 350° and 10°.
[0041] The present invention further relates to plant-based milk analogs prepared by the method according to the invention. Detailed Implementation
[0042] In some embodiments, the red bean concentrate has a protein content of at least 45% by weight, or at least 50% by weight, or between 45% and 70% by weight, or between 50% and 65% by weight, based on dry weight.
[0043] Additional ingredients, such as sugar, may be added as a buffer. In some embodiments, the phosphate source is dissolved in the plant protein mixture. Preferably, the phosphate source includes tricalcium phosphate and dipotassium hydrogen phosphate. Preferably, the sugar is sucrose. In some embodiments, the sugar is a sucrose substitute.
[0044] The plant protein mixture is optionally incubated with an enzyme to reduce the viscosity of the liquid. In some embodiments, the plant protein mixture is adjusted to a pH between 7 and 8, and then incubated with the enzyme. In some embodiments, the enzyme is an amylase and a glycoside hydrolase.
[0045] The plant protein mixture is emulsified. In some embodiments, a two-stage high-pressure homogenizer is used to form the emulsion. In some embodiments, the average particle size of the fat droplets in the emulsion is between 0.1 µm and 1 µm for d[3,2] and between 0.3 µm and 2 µm for d[4,3]. Preferably, the average particle size of the emulsion is between 0.1 µm and 0.7 µm for d[3,2] and between 0.3 µm and 1.5 µm for d[4,3], as measured by laser diffraction.
[0046] Red beet (Beta vulgaris Conditiva Group) extract is a liquid or powder made from concentrated juice of red beet (also known as beetroot, table beet, garden beet, dinner beet, or golden beet), maltodextrin or other carriers, and ascorbic acid or other antioxidants.
[0047] The emulsion is subjected to heat treatment to stabilize it microbiologically and reduce its viscosity. In some embodiments, the heat treatment is ultra-high temperature treatment (UHT).
[0048] Shear treatment is applied to the heat-treated emulsion. In some embodiments, a high-shear homogenizer is used to apply the shear treatment. In some embodiments, at 25°C and a shear rate of 12.7 s⁻¹, the viscosity of the plant-based liquid after shear treatment is between 0.1 mPa·s and 75 mPa·s, preferably less than between 0.5 mPa·s and 50 mPa·s, and more preferably between 15 mPa·s and 40 mPa·s.
[0049] Plant-based liquids typically have low starch content. In some embodiments, the plant-based liquid contains less than 2% by weight of starch, preferably less than 1% by weight of starch, and more preferably less than 0.5% by weight of starch.
[0050] Plant-based liquids can take several forms. In some embodiments, plant-based liquids are emulsion analogs.
[0051] The present invention also provides a plant-based milk analog prepared by the method described herein.
[0052] The present invention also provides a plant-based liquid comprising a plant protein source; optionally a hydrocolloid; and triglycerides.
[0053] In some embodiments, at 25°C and a shear rate of 10 s⁻¹, the plant-based liquid has a viscosity between 0.1 mPa·s and 100 mPa·s, preferably less than between 0.5 mPa·s and 30 mPa·s, and more preferably between 0.5 mPa·s and 15 mPa·s.
[0054] Plant-based liquids typically have low starch content. In some embodiments, the plant-based liquid contains less than 2% by weight of starch, preferably less than 1% by weight of starch, and more preferably less than 0.5% by weight of starch.
[0055] Unless otherwise specified, when compositions are described herein as weight percent, this means the total weight of the formulation.
[0056] As used herein, “about” should be understood to mean a number within a certain numerical range, such as -30% to +30% of the mentioned number, or -20% to +20% of the mentioned number, or -10% to +10% of the mentioned number, or -5% to +5% of the mentioned number, or -1% to +1% of the mentioned number. All numerical ranges herein should be understood to include all integers or fractions within that range. Furthermore, these numerical ranges should be understood to support claims involving any number or subset of numbers within that range. For example, the disclosure of 45 to 55 should be understood to support ranges of 46 to 54, 48 to 52, 49 to 51, 49.5 to 50.5, etc.
[0057] As used herein, an "analogy" of a substance is considered similar to the substance in one or more of its principal characteristics. As used herein, a "milk analog" will be similar to milk in purpose, use, and principal nutritional characteristics. It has similar levels of energy, protein, carbohydrates, vitamins, and minerals. Preferably, a milk analog is an analog of cow's milk.
[0058] The term "vegetarian" refers to an edible composition that contains no animal products or products of animal origin.
[0059] Plant protein sources based on broad beans, peas, chickpeas, lentils, cowpeas, pinto beans, mung beans, adzuki beans, common beans, kidney beans, navy beans, or similar high-carbohydrate (greater than 30% by weight) and low-fat (less than 15%) crops can be used.
[0060] Starch-degrading enzymes such as amylase, α-amylase (from any species, from Bacillus amyloliquefacien, Bacillus licheniformis, Aspergillus oryzae, Aspergillus niger) can be used, more preferably saccharifying α-amylase (e.g. from Bacillus subtilis (Bacillus subtilis saccharifying amylase)), or most preferably a combination of amylase and glucosylase (also known as amyloglucosidase or glycoside hydrolase, such as AMG 1100 BG from Novozymes), etc.
[0061] The fat source may include vegetable oils, animal fats, milk fats, fish oils, algae oils, sunflower oils, olive oils, low-erucic acid rapeseed oils, cottonseed oils, palm resins, palm stearin, palm kernel oils, corn oils, coconut oils, and / or high-oleic sunflower oils; any solid fat ingredients such as refined coconut oils, anhydrous milk fats, hydrogenated vegetable oils, tallow, lard, any nut butters / oils such as almond butter, peanut butter, walnut butter, cashew butter, and / or hydrogenated or partially hydrogenated fats. Preferably, the fat source is a plant-based fat source, such as vegetable oils, algae oils, sunflower oils, olive oils, low-erucic acid rapeseed oils, cottonseed oils, palm resins, palm stearin, palm kernel oils, corn oils, coconut oils, and / or high-oleic sunflower oils; any solid fat ingredients such as refined coconut oils, anhydrous milk fats, hydrogenated vegetable oils; any nut butters / oils such as almond butter, peanut butter, walnut butter, cashew butter, and / or hydrogenated or partially hydrogenated fats.
[0062] Sodium ascorbate alternatives include vitamin C, sodium ascorbate, calcium ascorbate, vitamin C palmitate, vitamin C-rich fruit juice (≥500mg vitamin C / 100mL), golden safflower extract, sodium bisulfite, iodine, potassium iodide, sorbic acid, potassium sorbate, and sulfite derivatives such as sodium sulfite, sodium bisulfite, sodium metabisulfite, potassium metabisulfite, calcium sulfite, and calcium bisulfite.
[0063] Buffer alternatives include dipotassium hydrogen phosphate, trisodium citrate, tripotassium citrate, tripotassium phosphate, sodium bicarbonate, baking soda, sodium bicarbonate, disodium hydrogen phosphate, trisodium phosphate, monopotassium phosphate, citric acid, and lemon juice.
[0064] Calcium sources include tricalcium phosphate, calcium carbonate, calcium glycerophosphate, and calcium citrate.
[0065] Sucrose substitutes include sucrose, bean sugar, glucose syrup, maltodextrin, honey, and other natural syrups such as agave. Preferably, the sucrose substitute is glucose syrup.
[0066] Hydrocolloids refer to stabilizers that can be based on (high or low acetyl) gellan gum, guar gum, (high or low methoxy) pectin, locust bean gum, alginate, carrageenan, carboxymethyl cellulose, microcrystalline cellulose, gel polysaccharides, xanthan gum, etc. In one embodiment, the hydrocolloid is gellan gum.
[0067] The fats in the plant protein mixture are emulsified. In some embodiments, a two-stage high-pressure homogenizer is used to form the emulsion. In some embodiments, the average particle size of the fat emulsion is between 0.1 µm and 1 µm for d[3,2] and between 0.3 µm and 2 µm for d[4,3], preferably between 0.1 µm and 0.7 µm for d[3,2] and between 0.3 µm and 1.5 µm for d[4,3], as measured by laser diffraction.
[0068] Pasteurization heat treatment can be carried out for 1 to 300 seconds in the range of 60℃-100℃.
[0069] The heat treatment (e.g., direct and indirect UHT heat treatment) can be carried out for 3 to 60 seconds in the range of 110°C to 150°C, preferably the heat treatment is indirect heat treatment.
[0070] For retorting heat treatment, the heat treatment delivered to the product should be designed to deliver a lethality (Fo) within the range of 5.0–15 minutes (or higher), but never less than 3.0 minutes. Once the rise time (CUT) to reach the predetermined minimum temperature during retorting is established, the time and temperature range that satisfies the lethality range is 7–25 minutes at 119–125°C during the sterilization step. The CUT and sterilization time are determined by a competent heat processing management body.
[0071] Plant protein blends typically contain up to 20% by weight of starch, preferably between 2% and 14% by weight, on a dry weight basis, and up to 20% by weight of fiber, preferably between 6% and 18% by weight.
[0072] Legumes are plants belonging to the family Fabaceae (or Leguminosae), and the seeds (also known as dried beans) of these plants. Legumes are agriculturally cultivated primarily for human consumption, as livestock feed and silage, and as green manure to enhance soil quality. As used herein, the term "legumes" may include: peas, broad beans, chickpeas, lentils, kidney beans, navy beans, pinto beans, lentils, lima beans, cotton beans, red beans, adzuki beans, mung beans, yellow-green beans, green peas, black beans, urad beans, kidney beans, garbanzo beans, blueberries, lima beans, green peas, snow peas, sweet peas, split peas, and black-eyed peas. Preferably, legumes are selected from adzuki beans, adzuki beans, peas, broad beans, chickpeas, white kidney beans, navy beans, and lentils.
[0073] Red bean (also known as adzuki bean, azuki bean, aduki bean, or red mung bean) is a flowering plant species of the legume family, specifically the adzuki bean.
[0074] The following examples illustrate various embodiments of the present invention by way of example rather than limitation.
[0075] Example
[0076] Example 1
[0077] Dairy products containing beetroot extract
[0078] Pink dairy products were prepared by dissolving 1 g of beetroot extract (Naturex beetroot extract HC PWS) in 2 L of whole milk. The product was then microbiologically stabilized by heat treatment at 138 °C for 15 s using a heat exchanger.
[0079] Example 2
[0080] Red bean milk without additives and beet extract
[0081] Pink red bean milk was prepared by dissolving 1.2 g of sodium bicarbonate in 1.8 L of water at 65 °C. Once the salt was dissolved, 39 g of air-fractionated red bean concentrate (52% protein dry weight) was added and dispersed with a rotor under stirring for 15 minutes to ensure good protein dissolution. 88 g of sugar and 2.4 g of gellan gum (high acyl 103B) were added to the red bean dispersion and mixed for 5 minutes. Then, 70 g of high oleic sunflower oil was added and mixed under high shear to obtain a pre-emulsion. Finally, 1 g of beetroot extract (Naturex beetroot extract HC PWS) was added to the pre-emulsion. A fine emulsion was then produced by passing the mixture through a two-stage high-pressure homogenizer (200 bar / 50 bar first / second stage homogenization pressure). The product was microbiologically stabilized by heat treatment at 138 °C for 15 s via a heat exchanger.
[0082] Example 3
[0083] Red bean milk with ascorbic acid and beetroot extract
[0084] Pink red bean milk was prepared by dissolving 1.2 g of sodium bicarbonate in 1.8 L of water at 65 °C. Once the salt was dissolved, 39 g of red bean concentrate and 1.4 g of sodium ascorbate were added and dispersed under stirring with a rotor stator for 15 minutes to ensure good protein dissolution. 88 g of sugar and 2.4 g of gellan gum (high acyl 103B) were added to the red bean dispersion and mixed for 5 minutes. Then, 70 g of high oleic sunflower oil was added and mixed under high shear to obtain a pre-emulsion. Finally, 1 g of beetroot extract (Naturex beetroot extract HC PWS) was added to the pre-emulsion. A fine emulsion was then produced by passing the mixture through a two-stage high-pressure homogenizer (200 bar / 50 bar first / second stage homogenization pressure). The product was microbiologically stabilized by heat treatment at 138 °C for 15 s via a heat exchanger.
[0085] Example 4
[0086] Red bean milk with tripotassium citrate and beetroot extract
[0087] Pink red bean milk was prepared by dissolving 1.2 g of sodium bicarbonate and 10 g of tripotassium citrate in 1.8 L of water at 65 °C. Once the salt was dissolved, 39 g of red bean concentrate was added and dispersed for 15 minutes under rotor-stator stirring to ensure good protein dissolution. 88 g of sugar and 2.4 g of gellan gum (high acyl 103B) were added to the red bean dispersion and mixed for 5 minutes. Then, 70 g of high oleic sunflower oil was added and mixed under high shear to obtain a pre-emulsion. Finally, 1 g of beetroot extract (Naturex beetroot extract HC PWS) was added to the pre-emulsion. A fine emulsion was then produced by passing the mixture through a two-stage high-pressure homogenizer (200 bar / 50 bar first / second stage homogenization pressure). The product was microbiologically stabilized by heat treatment at 138 °C for 15 s via a heat exchanger.
[0088] Example 5
[0089] Red bean milk with ascorbic acid and tripotassium citrate and beetroot extract
[0090] Pink red bean milk was prepared by dissolving 1.2 g of sodium bicarbonate and 10 g of tripotassium citrate in 1.8 L of water at 65 °C. Once the salt was dissolved, 39 g of red bean concentrate and 1.4 g of sodium ascorbate were added and dispersed under stirring with a rotor stator for 15 minutes to ensure good protein dissolution. 88 g of sugar and 2.4 g of gellan gum (high acyl 103B) were added to the red bean dispersion and mixed for 5 minutes. Then, 70 g of high oleic sunflower oil was added and mixed under high shear to obtain a pre-emulsion. Finally, 1 g of beetroot extract (Naturex beetroot extract HC PWS) was added to the pre-emulsion. A fine emulsion was then produced by passing the mixture through a two-stage high-pressure homogenizer (200 bar / 50 bar first / second stage homogenization pressure). The product was microbiologically stabilized by heat treatment at 138 °C for 15 s via a heat exchanger.
[0091] Example 6
[0092] Red result
[0093] Of all the milks, heat treatment altered their color, reducing the red hue and increasing the orange hue, resulting in a more orange appearance than pink milk. Product-grade milk was less affected by heat treatment and showed no color recovery over time. The four plant-based red bean milks were more significantly affected by heat treatment than product-grade milks, appearing more orange after heat treatment (lower a and higher b values), but recovered to a pinkish hue during storage at 4°C.
[0094] Adding ascorbic acid to the milk improved the rate of pink recovery, resulting in a higher a and lower b value after 10 weeks compared to the sample without added ascorbic acid. The combination of ascorbic acid and citrate resulted in the highest removal of orange hues, thus the milk became more pink over time, reaching a and b values close to those of the milk before heat treatment.
[0095]
Claims
1. A method for preparing a plant-based liquid, the method comprising: a. Dissolve the plant protein source in water to form a plant protein mixture with a pH of 6.5 or higher; b. At a pH greater than 6, add powdered or liquid red beet extract to the plant protein mixture and stir to dissolve; c. Optionally, the plant protein mixture is incubated together with the enzyme; d. Optionally, add a hydrocolloid to the plant protein mixture; e. Disperse the oil in the plant protein mixture; f. Homogenize the plant protein mixture to form an emulsion; g. Applying heat treatment to the emulsion; and h. Applying shear treatment to the heat-treated emulsion to form a plant-based liquid.
2. The method according to claim 1, wherein sodium ascorbate is dissolved in the plant protein mixture before or during step e).
3. The method according to claim 1, wherein sodium ascorbate and citric acid are dissolved in the plant protein mixture before or during step e).
4. The method according to claims 1 and 2, wherein the plant protein source is derived from legumes, such as red beans, adzuki beans, kidney beans, peas, broad beans, chickpeas, or lentils.
5. The method according to any of the preceding claims, wherein the sugar is dissolved in the plant protein mixture.
6. The method according to claim 4, wherein the calcium source comprises tricalcium phosphate, calcium citrate, or calcium carbonate.
7. The method according to any of the preceding claims, wherein the plant protein mixture is adjusted to a pH between 6.5 and 8 before incubation with the enzyme.
8. The method according to any of the preceding claims, wherein the enzyme is an amylase and a glycoside hydrolase.
9. The method according to any of the preceding claims, wherein the emulsion is formed using a two-stage high-pressure homogenizer.
10. The method according to any of the preceding claims, wherein the average particle size of the emulsion is less than 1 µm, as measured by laser diffraction.
11. The method according to any of the preceding claims, wherein the viscosity of the plant-based liquid is less than 75 mPa·s at 12.7 s⁻¹.
12. The method according to any of the preceding claims, wherein the plant-based liquid contains less than 0.5% starch.
13. The method according to any of the preceding claims, wherein the plant-based liquid has an A value >10 and a hue angle between 330° and 30°, preferably 345° and 15°, more preferably 350° and 10°.
14. A plant-based milk analogue, said plant-based milk analogue being prepared by the method according to claims 1 to 13.