Method for improving light stability of natural food coloring

Abstract

The invention discloses a method for improving the light stability of a natural food coloring, which discovers the color protection function of hesperetin and phloretin on the natural food coloring, and the hesperetin and phloretin can be added into food as color fixatives to delay the stability of the natural food coloring in food processing, storage and circulation processes. The color stability of the food in the shelf life is ensured, so that the market value of the food is improved, the loss is reduced, and the application value is remarkable.

Description

Technical Field

[0001] The invention belongs to the technical field of food additives, and in particular relates to a method for improving the photostability of natural edible pigments. Background Art

[0002] Edible pigments can be divided into two categories: natural edible pigments and synthetic pigments. Although synthetic pigments have the advantages of low cost, good stability, and easy use, more and more data indicate that many synthetic pigments will cause certain harm to the human body. As consumers' health awareness continues to increase, many synthetic pigments are gradually banned from use in the food and pharmaceutical industries. On the other hand, natural edible pigments come from nature. Most natural edible pigments are anthocyanins, flavonoids, and carrot compounds. Therefore, edible natural pigments are not only non-toxic and harmless, but also contain essential nutrients for the human body, or are vitamins or substances with vitamin properties. Some natural pigments also have certain pharmacological functions and have preventive and therapeutic effects on certain diseases. Therefore, edible natural pigments not only have coloring effects, but also have the effects of enhancing human functions, health care and disease prevention. The development and application of natural pigments have gradually attracted people's attention (Lu, X.; Li, W.; Wang, Q.; Wang, J.; Qin, S. Progress on the Extraction, Separation, Biological Activity, and Delivery of Natural Plant Pigments. Molecules, 2023, 28, 5364; Elvira Gonzalez de Mejia, Qiaozhi Zhang, Kayla Penta, Abdulkerim Eroglu, and Mary Ann Lila, The Colors of Health: Chemistry, Bioactivity, and Market Demand for Colorful Foods and Natural Food Sources of Colorants, Annual Review of Food Science and Technology, 2020, 11, 145). Commercially, the market size of natural pigments has also continued to expand, and the industry development trend is obviously positive.

[0003] The biggest disadvantage of natural pigments is the overall stability deviation. After being added to food, the color of natural pigments will gradually weaken and affect the quality of the product, which greatly limits the industrial development and application of natural pigments. Factors affecting the stability of natural pigments include pH, metal ions, temperature, light, etc. Many natural pigments are light-instable, and outdoor natural light or indoor scattered light can cause the decomposition of natural pigments. For example, capsanthin, exogenous superoxide anion radicals, hydroxyl radicals and other reactive oxygen free radicals (ROS) produced under light conditions can destroy the carbon-carbon double bonds, carbonyl and other chromophores of capsanthin, causing oxidative degradation and then generating colorless alcohol and losing color.

[0004] In order to improve the stability of natural pigments, the literature reports the use of colorants with antioxidant functions, such as tea polyphenols, ascorbic acid, sulfur dioxide and glutathione, etc. These colorants react with free radicals to quench free radicals by single electron reaction, and have the ability to remove free radicals. Due to the different structures of natural pigments, different colorants should be selected for different natural pigments, or compounded to achieve the best effect. For example, Chinese patent document CN115895292A discloses a colorant that improves the photostability of annatto orange pigment, which is a compound colorant of apple polyphenols, sodium isoascorbate, rutin and β-cyclodextrin. However, the compound colorant has more ingredients, which increases the ingredients and dosage of food additives to a certain extent.

[0005] Hesperidin (CAS: 69097-99-0) is mainly derived from young fruits of the genus Citrus in the Rutaceae family. It is a type of dihydroflavonoids and is a fragrance raw material allowed for use in our country. Chinese patent document CN102266320A discloses the function of hesperidin in improving skin microcirculation, and US patent document US08679461B2 and Chinese patent document CN101247734A disclose the use of hesperidin in enhancing the sweetness of sweet substances or the sweet olfactory impression of flavoring agents that give a sweet olfactory impression.

[0006] Phloretin (CAS: 60-82-2) is a plant polyphenol belonging to dihydrochalcone, which can be extracted from apple and grapefruit peels. Like hesperetin, it is a fragrance raw material allowed for use in our country. Chinese patent document CN112546032A discloses that phloretin is used as a dietary health product or supplement to prevent heavy metal cadmium poisoning, US patent document US2009286874A1 discloses the use of phloretin for anti-aging, US patent document US7427418B2 discloses the use of phloretin in cosmetics, US patent US20130316060A1 discloses the use of phloretin for modifying the sweetness of stevia and high-power synthetic sweeteners, and EU patent document EP2253226A1 discloses the use of phloretin to increase sweetness.

[0007] However, the performance of hesperidin and phloretin in protecting the stability of natural food pigments has never been reported in the literature. Summary of the invention

[0008] The purpose of the present invention is to propose the application of hesperidin and phloretin in protecting the stability of natural food pigments, so as to expand the selection range of light-stable color preservatives for natural food pigments.

[0009] In view of this, the scheme of the present invention is:

[0010] In a first aspect, the present invention provides a method for improving the photostability of natural food pigments, wherein a color protectant is used in combination with the natural food pigments, wherein the color protectant is selected from hesperetin and / or phloretin.

[0011] Furthermore, the natural food coloring includes at least one of annatto, monascus red, monascus yellow, betalain, and capsanthin; more preferably, capsanthin.

[0012] Furthermore, the method allows the color retaining agent and the natural food pigment to coexist in the solution.

[0013] Preferably, the mass ratio of the color preservative to the natural edible pigment is (0.25-1):1.

[0014] Preferably, the mass ratio of the color preservative to the natural food pigment is 0.5:1.

[0015] The second aspect of the present invention provides the use of hesperetin and / or phloretin as a color preservative for natural food pigments in food or beverages, wherein the color preservative is used to improve the light stability of the natural food pigments and prolong the color duration of the food or beverages.

[0016] The third aspect of the present invention provides a method for stabilizing the color of food or beverage, wherein the food or beverage has natural food pigment added thereto; the method comprises adding a color preservative to the food or beverage, wherein the color preservative is selected from hesperetin and / or phloretin.

[0017] Furthermore, the color protecting agent is added in an amount of 40-200 ppm.

[0018] Furthermore, the food includes processed solid foods that can add natural edible pigments under food standards, such as pickled products, marinated products, condiments, canned foods, sauces, popsicles, ice cream, popsicles, biscuits, cooked meat products, artificial crab meat, etc. Pickled products and marinated products are more specifically flavored small fish and shrimps, marinated eggs, marinated bean products, marinated meat products, spicy puffed foods, etc.

[0019] Furthermore, the beverages include fruit juice, soda and blended wine.

[0020] Compared with the prior art, the beneficial effects of the present invention include but are not limited to:

[0021] The present invention discovers for the first time the color protection function of hesperetin and phloretin on natural edible pigments. Hesperetin and phloretin can be added to foods as color protection agents to delay the stability of edible natural edible pigments during food processing, storage and circulation, thereby ensuring the color stability of foods during the shelf life, thereby improving the market value of foods and reducing losses, and has significant application value. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and beneficial technical effects of the present invention clearer, the technical scheme of the present invention is further described in detail in conjunction with the embodiments. It should be understood that the specific implementation methods described in this specification are only for explaining the present invention, not for limiting the present invention.

[0023] In one embodiment, the inventors found that hesperidin and phloretin can protect the color of natural food pigments and improve the photostability of natural food pigments. Therefore, hesperidin and / or phloretin can be used as natural food pigment color protectors. On the one hand, they can be used alone to protect the photostability of natural food pigments, and on the other hand, they can be used in food or beverages to extend the color duration of food or beverages.

[0024] It should be noted that it is generally believed that colorants with antioxidant functions, such as tea polyphenols, ascorbic acid, sulfur dioxide and glutathione, can improve the stability of natural food pigments. These colorants react with free radicals in the environment to quench free radicals by single electron reaction, thus protecting the pigment molecules from oxidative degradation and fading. Unexpectedly, the structures of capsanthin and β-carotene are similar. Although phloretin and hesperidin have significant color protection effects on capsanthin, phloretin and hesperidin have almost no color protection effect on β-carotene.

[0025] Capsanthin:

[0026]

[0027] Beta-Carotene:

[0028]

[0029] Therefore, in the above examples, it is disclosed for the first time that phloretin and hesperetin have a significant color-protecting function for capsanthin, and the color-protecting function is not achieved through their antioxidant properties.

[0030] In a preferred embodiment, when the color protecting agent and the natural food pigment coexist, the mass ratio of the color protecting agent to the natural food pigment is (0.25-1):1, which can exert a significant color protecting effect, and more preferably 0.5:1.

[0031] In a preferred embodiment, when the color preservative is added to food or beverage to improve the stability of natural food pigments, the amount of the color preservative added is 40-200 ppm under the premise that the natural food pigments are added in accordance with relevant standards.

[0032] In the following examples, hesperetin and phloretin are both prepared into 1% (by weight) propylene glycol solution for use, and other ingredients are reagents or additives under the commercial standards in the field.

[0033] Example 1 The color protection effect of hesperetin and phloretin on the natural pigment annatto.

[0034] Test method:

[0035] 1) Dilute the prepared 0.04% annatto solution by 20 ml (0.008 g) to 80 ml, take some samples and put them into the spectrometer, and perform spectrum test at a wavelength of 482 nm to test the original absorbance value;

[0036] 2) Add different doses of 1% hesperidin or phloretin solution to the diluted annatto solution to prepare samples (#1-9) of different concentrations. 100 ml of each prepared sample (#1-9, see Table 1 for details) was placed in a colorless transparent beverage bottle and placed on the windowsill to receive natural light and indoor light. After 10 days, the 9 samples were diluted 4 times for spectral testing, and the retention rate of annatto pigment in each sample was calculated based on the absorbance value. The test results are as follows:

[0037] Table 1: Annatto orange pigment stability test

[0038]

[0039] Light has a great influence on annatto. Different added amounts of hesperidin or phloretin have different color protection effects. The larger the added amount, the better the color protection effect. When hesperidin and phloretin are added at the optimal amount of 0.6%, they have a comparable color protection effect on annatto with the composite color protection agent disclosed in patent CN115895292B.

[0040] Example 2 Effect of hesperidin and phloretin on the color protection of natural pigment Monascus red

[0041] Test method:

[0042] 1) Prepare 0.03% red yeast rice solution, take 20ml and dilute to 140ml, take some samples and put them into the spectrometer, and perform spectrum test at a wavelength of 489nm to test the original absorbance value;

[0043] 2) 100 ml of each prepared sample (#1-8, see Table 2 for details) was placed in a colorless transparent beverage bottle and placed on a windowsill to receive natural light and indoor light. After 10 days, the eight samples were diluted 7 times and tested at a wavelength of 489nm. The retention rate of red pigment of each sample was calculated based on the absorbance value. The test results are as follows:

[0044] Table 2: Monascus red pigment stability test

[0045]

[0046]

[0047] Light has a significant effect on Monascus red, with the retention rates of Monascus red in samples #3 (added with 0.6% of a 1% hesperidin solution) and #7 (added with 1% of a 1% phloretin solution) being twice that of sample #1 without the addition of a color preservative.

[0048] Example 3 Effect of hesperetin and phloretin on color protection of marinated eggs using red yeast rice

[0049] Table 3: Raw materials for preparing braised eggs

[0050] Ingredients Sample A (g) Sample B (g) Sample C (g) egg 1000 1000 1000 water 4000 3996 3996 Salt 90 90 90 spices 20 20 20 white sugar 50 50 50 MSG 10 10 10 salad oil 20 20 20 Chicken flavor 8 8 8 Monascus red pigment 1 1 1 Phloretin 1% solution 0 40 0 Hesperetin 1% solution 0 0 40

[0051] Using the raw material ratios in Table 3, three types of marinated egg samples were prepared through five steps: pre-cooking, shelling, braising, packaging, and sterilization. After packaging in transparent bags, they were placed in a bright window sill for testing. After 2 months, the red color of marinated egg A without color preservatives faded significantly; the color of marinated eggs B and C with color preservatives remained relatively good. Accelerated experiments (38°C oven) confirmed that within the 6-month shelf life, the color of marinated eggs B and C remained better, while marinated egg A faded more seriously.

[0052] Example 4 The color protection effect of hesperetin and phloretin on the natural pigment Monascus yellow.

[0053] Test method:

[0054] 1) Prepare 0.04% Monascus yellow solution, take 20ml and dilute to 200ml, take some samples and put them into the spectrometer, perform spectrum test at a wavelength of 491nm, and test the original absorbance value;

[0055] 2) 100 ml of each prepared sample (#1-8, see Table 4 for details) was placed in a colorless transparent beverage bottle and placed on a windowsill to receive natural light and indoor light. After 10 days, the eight samples were diluted 10 times and tested for spectrum at a wavelength of 491nm. The retention rate of Monascus yellow pigment in each sample was calculated based on the absorbance value. The test results are as follows:

[0056] Table 4: Stability test of Monascus yellow

[0057]

[0058] Sunlight has a greater impact on Monascus yellow, and phloretin has a better color protection effect on Monascus yellow than hesperetin. The retention rate of Monascus yellow pigment in sample #7 (1% phloretin solution added) is 2.3 times that of sample #1 without color protection agent.

[0059] Example 5 Effect of Phloretin on Color Protection of Red Rice Eggs Using Monascus Yellow Pigment

[0060] Table 5: Braised eggs using red yeast rice

[0061]

[0062]

[0063] Using the raw material ratio in Table 5, three samples of brined eggs were prepared through five steps: pre-cooking, shelling, braising, packaging, and sterilization. After packaging in a transparent bag, the eggs were placed in a bright window for testing. After 2 months, the color of brined egg sample A without color preservative was significantly faded; the color of brined egg sample B with color preservative was relatively well maintained. Accelerated experiments (38°C oven) confirmed that within the 6-month shelf life, brined egg sample B basically maintained its color, while brined egg sample A faded significantly.

[0064] Example 6 The color protection effect of hesperetin and phloretin on the natural pigment beetroot red.

[0065] Test method:

[0066] 1) Prepare 0.02% beetroot red solution, take 20ml and dilute to 60ml, take some samples and put them into the spectrometer, perform spectrum test at a wavelength of 534nm, and test the original absorbance value;

[0067] 2) 100 ml of each prepared sample (#1-8, see Table 6 for details) was placed in a colorless transparent beverage bottle and placed on a windowsill to receive natural light and indoor light. After 10 days, the eight samples were diluted 3 times and tested for spectrum at a wavelength of 534 nm. The betalain retention rate of each sample was calculated based on the absorbance value. The test results are as follows:

[0068] Table 6: Test of beetroot red pigment stability

[0069]

[0070]

[0071] Light has a greater impact on Monascus yellow. When phloretin and hesperetin are used alone, the color protection effect on beetroot red is not obvious. When used in combination (sample #8), the effect is very good. The pigment retention rate of beetroot red is twice that of not using color protection agent (sample #1).

[0072] Example 7: Color protection effect of hesperidin and phloretin on natural pigment capsanthin

[0073] Test method: 1) Prepare 0.05% capsanthin solution, take 20ml and dilute to 60ml, take some samples and put them into the spectrometer, and test the spectrum at a wavelength of 461nm to test the original absorbance value; 2) Put 100ml of the prepared samples (#1-8, see Table 7 for details) into colorless and transparent beverage bottles, and place them on the windowsill to receive natural light and indoor light. After 10 days, the 8 samples were diluted 3 times and tested at a wavelength of 461nm. The retention rate of capsanthin pigment in each sample was calculated based on the absorbance value. The test results are as follows:

[0074] Table 7: Test of the stability of capsanthin

[0075]

[0076] Phloretin and hesperidin have a significant color protection effect on capsanthin. The retention rate of capsanthin in samples with phloretin and hesperidin is 3-4 times that of samples without color protection agents.

[0077] Example 8: Effect of phloretin and hesperetin on the color protection of red guava juice using capsanthin

[0078] Table 8: Juice using red pepper

[0079]

[0080]

[0081] The ingredients in Table 8 were used to prepare red guava juice through the steps of mixing, heating, filling and sterilization, and then the juice was bottled in transparent beverage bottles and placed in a bright window sill to receive light. After 30 days, it can be seen that the juice sample A without adding color preservatives has obvious fading, while the juice samples B and C with added color preservatives have not faded significantly.

[0082] Example 9: The color protection effect of phloretin and hesperetin on spicy strips using capsanthin

[0083] Table 9: Spicy strips using capsanthin

[0084]

[0085] Using the raw material ratio in Table 9, three spicy strips samples were prepared through five steps: dough mixing, puffing, molding, seasoning, sterilization, and packaging. After packaging in a transparent bag, the samples were placed in a bright window sill for testing. After 2 months, the color of spicy strips sample A without adding color preservatives faded significantly; the color of spicy strips samples B and C with added phloretin and hesperidin color preservatives remained very good. Accelerated experiments (38°C oven) confirmed that within the 6-month shelf life, spicy strips samples B and C with added phloretin and hesperidin color preservatives basically maintained their color, while sample A without adding color preservatives faded significantly.

[0086] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A method for improving the photostability of natural food pigments, characterized in that: A color protectant is used to coexist with natural food coloring, and the color protectant is selected from hesperetin and / or phloretin.

2. The method according to claim 1, characterized in that The natural food coloring comprises at least one of annatto, monascus red, monascus yellow, beetroot red and capsicum red.

3. The method according to claim 1, characterized in that The method comprises coexisting a color protection agent and a natural food coloring in a solution.

4. The method according to claim 3, characterized in that The mass ratio of the color preservative to the natural edible pigment is (0.25-1):

1.

5. The method according to claim 3, characterized in that: The mass ratio of the color preservative to the natural food pigment is 0.5:

1.

6. Use of hesperidin and / or phloretin as a natural food pigment coloring agent in food or beverage.

7. A method for stabilizing the color of food or beverage, wherein natural food coloring is added to the food or beverage; characterized in that: The method comprises adding a color protecting agent to food or beverage, wherein the color protecting agent is selected from hesperetin and / or phloretin.

8. The method according to claim 7, characterized in that The added amount of the color protecting agent is 40-200ppm.

9. The method according to claim 7, characterized in that: The foods include pickled products, marinated products, condiments, canned foods, sauces, popsicles, ice cream, popsicles, biscuits, cooked meat products, and artificial crab meat.

10. The method according to claim 7, characterized in that The beverages include fruit juice, soda and prepared wine.

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