Stabilizer composition for a beverage and use

Abstract

This invention discloses a stabilizer composition for beverages and its uses, belonging to the field of food additives technology. The stabilizer composition is characterized by being a mixture of glutamic acid-N,N-diacetic acid and methylglycine-N,N-diacetic acid, both of which exhibit good biodegradability and high safety, representing a promising direction for the development of novel food chelating agents. The stabilizer composition is added to the beverage before the addition of citric acid. The beverage is unadjusted anthocyanin-containing berry juice. The beneficial effects of this invention are: chelation followed by acid adjustment and the GLDA / MGDA dual-targeting compound system, which removes all trace amounts of Fe³⁺ before citric acid contacts the juice. + Cu² + Ca² + Coordination saturation eliminates the reaction substrate competing for coordination with citric acid; at the same time, the synergistic effect of the highly hydrated chelate / complex products formed by GLDA and MGDA counteracts the colloidal instability caused by the increased ionic strength of citrate, achieving an unexpected dual stabilizing effect.

Description

Technical Field

[0001] This invention belongs to the field of food additive technology, and more specifically relates to stabilizer compositions for beverages and their uses. Background Technology

[0002] Natural anthocyanins are widely found in the juices of berries such as blueberries, cranberries, blackcurrants, and red grapes. They possess both high antioxidant activity and a distinctive purplish-red color, making them a core value component of high-end functional juices.

[0003] In the industrial production of berry juice, in order to preserve the bioactivity and color of anthocyanins to the greatest extent, a low-temperature inert gas protection process is usually adopted. Carbon dioxide or nitrogen is generally used for replacement to reduce the oxidative damage to anthocyanins caused by dissolved oxygen.

[0004] In addition, carotenoid components such as lutein, which coexist naturally in berry raw materials, belong to the same family of natural pigments as anthocyanins. However, due to their fat-soluble characteristics, they mainly exist in the form of suspended particles in the aqueous phase of fruit juice. Their stability and the aqueous oxidation behavior of anthocyanins belong to different degradation pathways. The quality degradation of the two during processing and storage usually needs to be paid attention to separately.

[0005] When anthocyanin-rich juice is produced industrially, anthocyanins maintain stable color and vibrant hue in the acidic pH range of 3.0 to 3.8. Therefore, industry standard processes use food-grade citric acid or trisodium citrate to adjust the pH of the juice to acidity. Citric acid is an irreplaceable acidity regulator and preservative in the food industry, possessing comprehensive advantages such as mild acidity, harmonious flavor, and GRAS safety certification. Citric acid is a weak tricarboxylic acid chelating agent and preservative, capable of transiently binding trace amounts of Fe³⁺ within the system. + Cu² + Ca² + Initially, the color and clarity of the blended juice were superior to the original juice without organic acids. However, the complexes formed by citric acid and various metal ions have low stability constants and reversible coordination. Under conditions of room temperature storage, pasteurization, and fluctuating storage and transportation temperatures, they continue to dissociate, triggering two simultaneous and mutually reinforcing pathways of quality deterioration: (1) Fe³ released by dissociation + Cu² + As a catalytic center, it initiates a Fenton-like reaction, continuously attacking the conjugated structure of anthocyanin molecules, triggering ring-opening degradation of pigments and fading and browning of product color. (2) Ca² released by dissociation +Crosslinking with methyl ester pectin forms a three-dimensional "egg-box" aggregate; at the same time, citrate dissociates to increase the ionic strength of the system, compresses the double electric layer of pectin colloidal particles, and reduces the electrostatic repulsion of particles. Citric acid has no large molecular hydration steric hindrance structure and cannot counteract the colloidal instability caused by ionic strength. Under the dual effect, the juice shows obvious turbidity and flocculent precipitation during storage. Summary of the Invention

[0006] To address the aforementioned problems and overcome the shortcomings of existing technologies, this invention provides a beverage stabilizer composition and its uses, which can effectively solve the problems of oxidation and turbidity defects caused by the addition of citric acid to berry juice.

[0007] The specific technical solution of the present invention to solve the above-mentioned technical problems is as follows: A stabilizer composition for a beverage, characterized in that the stabilizer composition is a mixture of glutamic acid-N,N-diacetic acid (GLDA) and methylglycine-N,N-diacetic acid (MGDA), both of which have good biodegradability and high safety, and represent a direction for the development of novel food chelating agents.

[0008] The stabilizer composition is added to the beverage before citric acid is added; the beverage is an anthocyanin-containing berry juice that has not been acidified. The concentration range of the composition is 10 and 100 mg / kg; The molar ratio of GLDA to MGDA is 1.5:1 to 3:1.

[0009] The stabilizer composition is used in the preparation of beverages.

[0010] The steps for preparing beverages using stabilizer compositions include: S1 is extracted from unadjusted anthocyanin-containing berry juice; S2 adds a stabilizer composition to berry juice. After S3 has fully complexed, citric acid or trisodium citrate is added to the system to adjust the overall pH to 3.0-4.5, preferably 3.3-3.7. S4 homogenized mixture is then filled.

[0011] The beneficial effects of this invention are: This invention employs a unique process sequence of simultaneously adding GLDA+MGDA compound chelating agent to fully complex endogenous metals, followed by adding citric acid to adjust pH. This solves the problem of conventional fruit juice processes that only use citric acid to adjust acidity in existing technologies. Because citric acid has a reversible weak coordination with metals, anthocyanin oxidation and pectin aggregation and turbidity occur simultaneously during storage, resulting in serious quality defects during product shelf life. This is a fundamental pain point that the industry urgently needs to address. The present invention's pre-chelation followed by acid adjustment and GLDA / MGDA dual-targeting compound system removes all trace amounts of Fe³⁺ before citric acid comes into contact with the fruit juice. +Cu² + Ca² + Coordination saturation eliminates the reaction substrate competing for coordination with citric acid; at the same time, the synergistic effect of the highly hydrated chelate / complex products formed by GLDA and MGDA counteracts the colloidal instability caused by the increased ionic strength of citrate, achieving an unexpected dual stabilizing effect. The chelation-adjustment and GLDA / MGDA dual-targeting compound system of the present invention can control the anthocyanin oxidation rate and turbidity at extremely low levels, and the anthocyanin retention rate exceeds 96% after 30 days of high-temperature accelerated storage. Attached Figure Description

[0012] Appendix Figure 1 These are experimental diagrams showing the initial state of beverage preparation in the embodiments and comparative examples of the present invention; Appendix Figure 2 These are experimental diagrams showing the state of beverages prepared according to embodiments and comparative examples of the present invention after 30 days of storage. Detailed Implementation The specific details in the description of this invention are merely for the purpose of fully understanding the embodiments of the invention. However, those skilled in the art should know that the implementation of the invention is not limited to these details. In addition, well-known structures and functions have not been described or shown in detail to avoid obscuring the key points of the embodiments of the invention. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0013] Specific embodiments of the present invention: To better understand the present invention, specific embodiments are described. It is worth emphasizing that the effects of these embodiments are not substantially different from those of various embodiments within the scope of protection of the present invention, including their respective reagents and reagent content ratios. All of them can achieve the effects described in the present invention and solve the above-mentioned problems. Other combinations are not described here. Example 1: Take 500 mL of blueberry juice that has not been pretreated (washed, crushed, enzymatically hydrolyzed, and coarsely filtered) and is not acidified to contain anthocyanins. Under nitrogen protection, add GLDA and MGDA to the juice simultaneously at a rate of 100 mg / kg. The molar ratio of GLDA to MGDA is 1.5:1. Stir to allow the complexation reaction to proceed fully, then add food-grade citric acid to adjust the pH to 3.3, homogenize, fill, and store at 40°C in the dark for 30 days.

[0014] Example 2: Take 500 mL of blueberry juice that has not been pretreated (washed, crushed, enzymatically hydrolyzed, and coarsely filtered) and is not acidified to contain anthocyanins. Under nitrogen protection, add GLDA and MGDA to the juice simultaneously at a rate of 10 mg / kg. The molar ratio of GLDA to MGDA is 2.5:1. Stir to allow the complexation reaction to proceed fully, then add food-grade citric acid to adjust the pH to 3.5, homogenize, fill, and store at 40°C in the dark for 30 days.

[0015] Example 3: Take 500 mL of blueberry juice that has not been pretreated (washed, crushed, enzymatically hydrolyzed, and coarsely filtered) and is not acidified to contain anthocyanins. Under nitrogen protection, add GLDA and MGDA to the juice simultaneously at a rate of 60 mg / kg. The molar ratio of GLDA to MGDA is 3:1. Stir to allow the complexation reaction to proceed fully, then add food-grade citric acid to adjust the pH to 3.7, homogenize, fill, and store at 40°C in the dark for 30 days.

[0016] Detection methods Turbidity determination: Visual inspection is used to check for the presence of insoluble matter; Anthocyanin retention rate determination: The absorbance of the samples at 520 nm and 700 nm in pH 1.0 and pH 4.5 buffer solutions was measured using the pH differential method. The total anthocyanin content was calculated, and the retention rate was calculated with day 0 as 100%. See Appendix for details. Figure 1-2 .

[0017] To more intuitively demonstrate the technological advantages of this invention, a comparison is made between the method of this invention and the same process using equivalent substitution. Comparative Example 1: The method used is as follows: 500mL of anthocyanin-containing berry juice, specifically, food-grade citric acid is added directly to adjust the pH to 3.5, without adding any chelating agents or stabilizers, homogenized and then bottled, and stored at 40℃ in the dark for 30 days. Comparative Example 2: Similar to Comparative Example 1, except that the pH was adjusted with citric acid first, and then the chelating agent GLDA was added. Take 500mL of blueberry juice, first add citric acid to adjust the pH to 3.5, then add an equal amount of GLDA, stir for 30 minutes and then fill the bottle. Store at 40℃ away from light for 30 days. Comparative Example 3: Similar to Comparative Example 1, except that the pH was adjusted with citric acid first, and then the chelating agent MGDA was added. Take 500mL of blueberry juice, first add citric acid to adjust the pH to 3.5, then add an equal amount of MGDA, stir for 30 minutes and then fill the bottle. Store at 40℃ away from light for 30 days. Comparative Example 4: Similar to Comparative Example 1, except that the pH was adjusted with citric acid first, and then an equal amount of the compound chelating agent EDDS+MGDA was added. Take 500mL of blueberry juice, first add citric acid to adjust the pH to 3.5, then add equal amounts of EDDS and MGDA, stir for 30 minutes and then fill the bottle, store at 40℃ away from light for 30 days; Comparative Example 5: Similar to Comparative Example 1, except that equal amounts of EDDS+MGDA were added first, followed by citric acid to adjust the pH. Take 500mL of blueberry juice, add equal amounts of EDDS and MGDA, stir for 30 minutes, then add citric acid to adjust the pH to 3.5, bottle, and store at 40℃ away from light for 30 days.

[0018] Table 1: Analysis of experimental results of anthocyanin-containing berry juice treated in different embodiments and comparative examples

[0019] Analysis of the data in Table 1 shows that: (1) As can be seen from Examples 1-3: This invention utilizes GLDA and MGDA in a citric acid-free juice environment, pre-mixed with Fe³⁺ + / Cu² + Ca² + Complete the coordination reaction; GLDA can react with Fe³⁺ + / Cu² + It forms a stable octahedral coordination configuration (including coordinated water molecules). This chelate exhibits kinetic inertness under weakly acidic conditions and has an extremely slow dissociation rate; MGDA and Ca² + Formation of stable hydrated complexes, blocking Ca² + The pectin cross-linking activity; When citric acid is added in the later stage, since there are no free metal ions available for coordination in the system, and the existing metal-GLDA / MGDA complex is kinetically stable under weakly acidic conditions with a high activation energy for ligand exchange reactions, citrate ions cannot replace metal ions within the storage timescale, thus preventing the formation of a weak citric acid-metal complex; simultaneously, [Ca(MGDA)]... - The hydration layer of the complex provides steric hindrance, which counteracts the tendency of colloidal instability caused by the increased ionic strength of citrate, thereby achieving both long-lasting color protection and juice clarification.

[0020] (2) In Comparative Example 1, the turbidity after storage was 3.2 NTU, and the anthocyanin retention rate was only 68.3% after 30 days at 40℃. Obvious browning and flocculent precipitate at the bottom were visible to the naked eye. The reason for the above problem may be: citrate ions and Fe³⁺+ Cu² + Ca² + Formation of weakly reversible complexes, with continuous dissociation and release of free metal ions during storage, Fe³ + / Cu² + Catalytic oxidation of anthocyanins, Ca² + Cross-linked pectin forms aggregates, while citrate increases ionic strength and intensifies colloidal aggregation.

[0021] (3) In Comparative Example 2, the turbidity after storage was 2.8 NTU, and the pigment retention rate was 82.6%; The reason for the above problem may be that GLDA can effectively complex Fe³⁺. + / Cu² + It inhibits oxidation, but the free Ca²⁺ added beforehand by citric acid + It remains bound to citric acid and continues to dissociate during storage, releasing Ca²⁺. + Cross-linked pectin has a larger particle size and higher turbidity, and the problem of pectin aggregation and turbidity has not been solved.

[0022] (4) In Comparative Example 3, the flower turbidity after storage was 0.9 NTU, and the pigment retention rate was 79.3%; The reason for the above problem may be that MGDA can effectively complex Ca²⁺. + Pectin aggregation was controlled, but citric acid pre-occupied Fe³ + / Cu² + During storage, anthocyanins continue to dissociate, resulting in severe oxidation and low pigment retention.

[0023] (5) In Comparative Example 4, the turbidity after storage was 1.3 NTU, and the pigment retention rate was 86.1%. The reason for the above problem may be that although MGDA controls Ca² + EDDS has a thin hydration layer, which is beneficial to Fe³⁺. + / Cu² + The complexation stability of the EDDS is insufficient in the presence of citric acid; however, there is no synergistic effect between EDDS and MGDA, and the oxidation inhibition effect is limited, so the overall performance is not as good as that of this invention.

[0024] (6) In Comparative Example 5, the turbidity after storage was 1.2 NTU, and the pigment retention rate was 86.6%; The reason for the above problem may be: EDDS affects Fe³ + / Cu² + The complexation stability of EDDS is unstable under weakly acidic conditions, and subsequent high concentrations of citrate can gradually displace the metal ions complexed with EDDS; the hydration layer of EDDS is thin, and the Ca²⁺ complexed with MGDA is relatively stable. +There is no synergistic steric hindrance effect between them, which cannot offset the risk of colloidal instability caused by the increased ionic strength of citrate; the pigment retention rate and turbidity are significantly inferior to those of the present invention.

[0025] therefore: This invention employs a unique process sequence of simultaneously adding GLDA+MGDA compound chelating agent to fully complex endogenous metals, followed by adding citric acid to adjust pH. This solves the problem of conventional fruit juice processes that only use citric acid to adjust acidity in existing technologies. Because citric acid has a reversible weak coordination with metals, anthocyanin oxidation and pectin aggregation and turbidity occur simultaneously during storage, resulting in serious quality defects during product shelf life. This is a fundamental pain point that the industry urgently needs to address. The present invention's pre-chelation followed by acid adjustment and GLDA / MGDA dual-targeting compound system removes all trace amounts of Fe³⁺ before citric acid comes into contact with the fruit juice. + Cu² + Ca² + Coordination saturation eliminates the reaction substrate competing for coordination with citric acid; at the same time, the synergistic effect of the highly hydrated chelate / complex products formed by GLDA and MGDA counteracts the colloidal instability caused by the increased ionic strength of citrate, achieving an unexpected dual stabilizing effect.

[0026] The chelation-adjustment and GLDA / MGDA dual-targeting compound system of the present invention can control the anthocyanin oxidation rate and turbidity at extremely low levels, and the anthocyanin retention rate exceeds 96% after 30 days of high-temperature accelerated storage.

Claims

1. A stabilizer composition for a beverage, characterized in that... The stabilizer composition is a mixture of glutamic acid-N,N-diacetic acid and methylglycine-N,N-diacetic acid, and the stabilizer composition is added before citric acid is added to the beverage; the beverage is unacidified anthocyanin-containing berry juice.

2. The stabilizer composition for beverages according to claim 1, characterized in that... The concentration range of the stabilizer composition in the beverage is 10-100 mg / kg.

3. The stabilizer composition for beverages according to claim 1, characterized in that... The molar ratio of glutamic acid-N,N-diacetic acid and methylglycine-N,N-diacetic acid is 1.5:1 to 3:

1.

4. The use of a stabilizer composition for a beverage, characterized in that... Stabilizer combinations are used in the preparation of beverages.

5. The use of the beverage stabilizer composition according to claim 4, characterized in that... The steps for preparing a beverage include: S1 is extracted from unadjusted anthocyanin-containing berry juice; S2 adds a stabilizer composition to berry juice. After S3 has fully complexed, add citric acid or trisodium citrate to the system to adjust the overall pH to 3.0-4.

5. S4 homogenized mixture is then filled.

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