V-type starch and application thereof in embedding lutein oil

Abstract

The invention provides V-type starch and an application of the V-type starch in embedding lutein grease. The method comprises the following steps: gelatinizing starch, dropwise adding ethanol at 85-95 DEG C at a flow rate of 40-60 mL / h, and purifying to obtain the V-type starch. The V-type starch is used for embedding the lutein oil, so that the lutein can be uniformly distributed in a fermented flour product, the problems of uneven color, oil spots and the like are avoided, the lutein is more easily accepted by consumers, the oxidation stability of the lutein can be remarkably improved, and the retention rate of the lutein in the fermented flour product is further improved; the nutritional value of the fermented flour product is enhanced.

Description

Technical Field

[0001] This invention belongs to the field of food processing and fermentation engineering technology. More specifically, it relates to a V-type starch and its application in lutein-encapsulated oils. Background Technology

[0002] Fermented dough products, such as bread, steamed buns, dumplings, twisted rolls, soda crackers, steamed cakes, French flatbreads, pancakes, and fermented flatbreads, use yeast or other leavening agents to make the dough rise, become soft, and produce a unique flavor and texture, which are very popular with consumers.

[0003] With the increasing awareness of healthy eating, the development of fortified fermented flour products has become an important trend. Lutein is a carotenoid with important physiological activity. It can absorb specific wavelengths of visible light and scavenge free radicals, showing significant effects in visual protection and anti-oxidation. Adding it to fermented flour products can not only enhance their nutritional value but also give them a natural yellow color, meeting consumer demands for clean labeling. However, most fermented flour products require heat processing at temperatures above 100°C during production, and the hot and humid environment generated during fermentation greatly accelerates the oxidative degradation of lutein, leading to nutrient loss and color fading.

[0004] To improve the oxidative stability of lutein, current methods often involve dissolving lutein in oils to obtain lutein oil, followed by encapsulation using liposomes, microcapsules, and other systems. However, these methods require the use of various emulsifiers and antioxidants, resulting in high costs and complex processes, which are difficult to meet the demands for simplicity and low cost in the industrial production of fermented noodle products. Therefore, finding a method that can effectively improve the oxidative stability of lutein while being simple and inexpensive is crucial for the development of nutritionally fortified fermented noodle products. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a V-shaped starch that can be produced from low-cost materials such as starch, water, and ethanol using a simple process, without the need for additional emulsifiers or antioxidants. Furthermore, its use in encapsulating lutein oils significantly improves the oxidative stability of lutein and increases its retention rate in fermented noodle products.

[0006] The primary objective of this invention is to provide a method for preparing V-type starch.

[0007] A second objective of this invention is to provide V-type starch obtained by the above method.

[0008] A third objective of this invention is to provide the application of the above-mentioned V-type starch in lutein-encapsulated oils.

[0009] A fourth objective of this invention is to provide a nutritional enhancer.

[0010] The fifth objective of this invention is to provide the application of the above-mentioned nutrient enhancer in the preparation of fermented flour products.

[0011] The sixth objective of this invention is to provide a fermented dough product.

[0012] The above-mentioned objective of this invention is achieved through the following technical solution: This invention provides a method for preparing V-type starch, specifically: after gelatinizing starch, ethanol is added dropwise at a flow rate of 40-60 mL / h at 85-95 °C, and then purified to obtain V-type starch.

[0013] Preferably, the starch is one of corn starch, potato starch, wheat starch, and cassava starch.

[0014] Preferably, the gelatinization is performed by adding starch to water, mixing well, and heating until gelatinization.

[0015] More preferably, the starch has a mass percentage of 5% to 10% in the water, and most preferably 6%.

[0016] More preferably, the heating temperature is 95–100 °C, and most preferably 100 °C.

[0017] More preferably, the heating time is 50 to 70 minutes, and most preferably 60 minutes.

[0018] Preferably, the volume ratio of the gelatinized product to ethanol is 1:2 to 4, and most preferably 1:3.

[0019] Preferably, the ethanol is anhydrous ethanol.

[0020] Preferably, the ethanol is added at 500–700 rpm.

[0021] Preferably, the purification process involves cooling.

[0022] More preferably, the cooling is to cool to 20-30°C, and most preferably 25°C.

[0023] Preferably, the purification process involves solid-liquid separation, washing, and drying.

[0024] More preferably, the solid-liquid separation is performed by centrifugation, such as centrifugation at 3000-5000 rpm for 5-10 min.

[0025] More preferably, the washing is performed with ethanol, such as anhydrous ethanol.

[0026] More preferably, the drying temperature is 30–50 °C, and most preferably 40 °C.

[0027] Preferably, after purification, the material is further pulverized.

[0028] More preferably, the pulverization is performed to a mesh size of 80-120, and most preferably 100 mesh.

[0029] The V-shaped starch prepared by the above method has hydrophobic cavities, which can significantly improve the oxidative stability of lutein when used to encapsulate lutein oils, thereby significantly improving its retention rate in fermented noodle products. Therefore, the V-shaped starch prepared by the above method, and its application in encapsulating lutein oils, should be within the scope of protection of this invention.

[0030] Preferably, the method for preparing the lutein oil is as follows: after dissolving lutein in oil, water and oil are separated, and the resulting oil phase is the lutein oil.

[0031] More preferably, the oil is one or more of soybean oil, peanut oil, corn oil, and sunflower seed oil.

[0032] More preferably, the mass ratio of lutein to oil is 0.3 to 0.5:100.

[0033] More preferably, the dissolution is carried out under light-protected conditions.

[0034] More preferably, the dissolution temperature is 30–40 °C, and most preferably 35 °C.

[0035] More preferably, the dissolution time is 25 to 35 minutes, and most preferably 30 minutes.

[0036] More preferably, the dissolution is carried out at 600-700 rpm, and most preferably at 650 rpm.

[0037] More preferably, the water-oil separation is achieved by centrifugation, such as centrifugation at 4000-5000 rpm for 5-10 minutes.

[0038] Preferably, the mass ratio of the V-type starch to the lutein oil is 10:5 to 7, and most preferably 10:5.

[0039] Preferably, the encapsulation method is to mix V-type starch with lutein oil.

[0040] Based on this, the present invention also provides: (1) A nutrient enhancer obtained by encapsulating lutein oil in the above-mentioned V-type starch; (2) Application of the above-mentioned nutrient enhancers in the preparation of fermented flour products; (3) A fermented dough product with the above-mentioned nutritional enhancer added.

[0041] Preferably, the fermented dough product is one of the following: bread, steamed buns, dumplings, twisted rolls, soda crackers, steamed cakes, French flatbreads, pancakes, and fermented flatbreads.

[0042] The present invention has the following beneficial effects: 1. This invention uses low-cost materials such as starch, water, and ethanol, and specifically controls the dripping rate of ethanol. The resulting V-shaped starch is not prone to clumping, and no additional emulsifiers or antioxidants are required during the preparation process. No harmful byproducts are generated, making it suitable for the production of clean-label foods and easy to promote industrially.

[0043] 2. Using the V-shaped starch of the present invention to encapsulate lutein oil not only enables lutein to be evenly distributed in fermented flour products, avoiding problems such as uneven color and "oil spots", making it more acceptable to consumers, but also significantly improves the oxidative stability of lutein, thereby increasing its retention rate in fermented flour products and enhancing the nutritional value of fermented flour products. Detailed Implementation

[0044] The present invention will be further illustrated below with reference to specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods, and equipment used in the present invention are conventional reagents, methods, and equipment in this technical field.

[0045] Unless otherwise specified, all reagents and materials used in the following examples are commercially available.

[0046] Example 1: Preparation of a V-type starch Corn starch was mixed with water (the mass percentage of corn starch in water was 6%) and heated at 100 °C for 60 min (at which point the starch gelatinized). Then, anhydrous ethanol was added dropwise at 90 °C and 650 rpm using a constant flow pump at a flow rate of 50 mL / h (the volume ratio of gelatinized product to ethanol was 1:3). The mixture was then cooled to 25 °C and centrifuged at 4500 rpm for 5 min. The precipitate obtained by centrifugation was washed three times with anhydrous ethanol, dried in an oven at 40 °C, and finally pulverized to 100 mesh to obtain the V-shaped starch.

[0047] Example 2: Preparation of a V-type starch Corn starch was added to water and mixed well (the mass percentage of corn starch in water was 5%). The mixture was heated at 100 °C for 50 min (at which point the starch gelatinized). Then, anhydrous ethanol was added dropwise at 95 °C and 500 rpm using a constant flow pump at a flow rate of 40 mL / h (the volume ratio of gelatinized product to ethanol was 1:2). The mixture was then cooled to 30 °C and centrifuged at 3000 rpm for 10 min. The precipitate obtained by centrifugation was washed three times with anhydrous ethanol. The precipitate was then dried in an oven at 50 °C and finally pulverized to 80 mesh to obtain the V-shaped starch.

[0048] Example 3: Preparation of a V-type starch Corn starch was added to water and mixed well (the mass percentage of corn starch in water was 10%). The mixture was heated at 95 °C for 70 min (at which point the starch gelatinized). Then, anhydrous ethanol was added dropwise at 85 °C and 700 rpm using a constant flow pump at a flow rate of 60 mL / h (the volume ratio of gelatinized product to ethanol was 1:4). The mixture was then cooled to 20 °C and centrifuged at 5000 rpm for 5 min. The precipitate obtained by centrifugation was washed three times with anhydrous ethanol. The precipitate was then dried in an oven at 30 °C and finally pulverized to 120 mesh to obtain the V-shaped starch.

[0049] Comparative Example 1 Commercial pregelatinized starch (purchased from Henan Hengrui).

[0050] Comparative Example 2 Commercial porous starch (purchased from Yiruian Porous Starch).

[0051] Comparative Example 3 Corn starch.

[0052] Comparative Example 4 Same as Example 1, except that ethanol is added all at once. Specifically, this comparative example is as follows: Corn starch was mixed with water (the mass percentage of corn starch in water was 6%) and heated at 100 °C for 60 min (at which point the starch gelatinized). Then, anhydrous ethanol was added at 90 °C and 650 rpm (the volume ratio of gelatinized product to ethanol was 1:3). The mixture was then cooled to 25 °C and centrifuged at 4500 rpm for 5 min. The precipitate obtained by centrifugation was washed three times with anhydrous ethanol, dried in an oven at 40 °C, and finally pulverized to 100 mesh to obtain the V-shaped starch.

[0053] Test Example 1: Starch Agglomeration Test The starches obtained in Examples 1-3 and Comparative Examples 1-4 were added to water (to make the mass ratio of starch to water 1:10), and stirred at 300 rpm for 15 min. The starch solution was then observed to see if it clumped.

[0054] The results showed that the starches obtained in Examples 1-3 and Comparative Examples 1-4 did not have any clumping problems.

[0055] Test Example 2: Application of Starch in Encapsulating Lutein in Oils I. Preparation of Nutritional Enhancers (1) Nutritional enhancer 1 Lutein was added to soybean oil (the mass ratio of lutein to soybean oil was 0.4:100) in the dark and at 35 °C. After stirring at 650 rpm for 30 min, the mixture was centrifuged at 4500 rpm for 8 min. The resulting oil phase was the lutein oil, which was then mixed with the V-type starch obtained in Example 1 (the mass ratio of V-type starch to lutein oil was 10:5).

[0056] (2) Nutritional enhancer 2 The same as nutrient enhancer 1, except that the V-type starch obtained in Example 1 is replaced with the V-type starch obtained in Example 2. That is, nutrient enhancer 2 is: Lutein was added to soybean oil (the mass ratio of lutein to soybean oil was 0.4:100) in the dark and at 35 ℃. After stirring at 650 rpm for 30 min, the mixture was centrifuged at 4500 rpm for 8 min. The resulting oil phase was the lutein oil, which was then mixed with the V-type starch obtained in Example 2 (the mass ratio of V-type starch to lutein oil was 10:5).

[0057] (3) Nutritional enhancer 3 The same as nutrient enhancer 1, except that the V-type starch obtained in Example 1 is replaced with the V-type starch obtained in Example 3. That is, nutrient enhancer 3 is: Lutein was added to soybean oil (the mass ratio of lutein to soybean oil was 0.4:100) in the dark and at 35 °C. After stirring at 650 rpm for 30 min, the mixture was centrifuged at 4500 rpm for 8 min. The resulting oil phase was the lutein oil, which was then mixed with the V-type starch obtained in Example 3 (the mass ratio of V-type starch to lutein oil was 10:5).

[0058] (4) Nutritional enhancer 4 Similar to nutrient enhancer 1, the difference lies in the mass ratio of V-type starch to lutein oil obtained in Example 1: 10:6. Therefore, nutrient enhancer 4 is: Lutein was added to soybean oil (the mass ratio of lutein to soybean oil was 0.4:100) in the dark and at 35 °C. After stirring at 650 rpm for 30 min, the mixture was centrifuged at 4500 rpm for 8 min. The resulting oil phase was the lutein oil, which was then mixed with the V-type starch obtained in Example 1 (the mass ratio of V-type starch to lutein oil was 10:6).

[0059] (5) Nutritional enhancer 5 Similar to nutrient enhancer 1, the difference lies in the mass ratio of V-type starch to lutein oil obtained in Example 1 being 10:7. That is, nutrient enhancer 5 is: Lutein was added to soybean oil (the mass ratio of lutein to soybean oil was 0.4:100) in the dark and at 35 °C. After stirring at 650 rpm for 30 min, the mixture was centrifuged at 4500 rpm for 8 min. The resulting oil phase was the lutein oil, which was then mixed with the V-type starch obtained in Example 1 (the mass ratio of V-type starch to lutein oil was 10:7).

[0060] (6) Comparison of nutritional enhancer 1 The same as nutrient enhancer 1, except that the V-type starch obtained in Example 1 is replaced with the starch obtained in Comparative Example 1. That is, Comparative nutrient enhancer 1 is: In the dark and at 35 ℃, lutein was added to soybean oil (the mass ratio of lutein to soybean oil was 0.4:100), stirred at 650 rpm for 30 min, and then centrifuged at 4500 rpm for 8 min. The resulting oil phase was lutein oil, which was then mixed with the starch obtained in Comparative Example 1 (the mass ratio of starch to lutein oil was 10:5).

[0061] (7) Comparison of nutritional enhancer 2 The same as nutrient enhancer 1, except that the V-type starch obtained in Example 1 is replaced with the starch obtained in Comparative Example 2. That is, Comparative nutrient enhancer 2 is: In the dark and at 35 ℃, lutein was added to soybean oil (the mass ratio of lutein to soybean oil was 0.4:100), stirred at 650 rpm for 30 min, and then centrifuged at 4500 rpm for 8 min. The resulting oil phase was lutein oil, which was then mixed with the starch obtained in Comparative Example 2 (the mass ratio of starch to lutein oil was 10:5).

[0062] (8) Comparison of nutritional enhancer 3 The same as nutrient enhancer 1, except that the V-type starch obtained in Example 1 is replaced with the starch obtained in Comparative Example 3. That is, Comparative nutrient enhancer 3 is: In the dark and at 35 ℃, lutein was added to soybean oil (the mass ratio of lutein to soybean oil was 0.4:100), stirred at 650 rpm for 30 min, and then centrifuged at 4500 rpm for 8 min. The resulting oil phase was lutein oil, which was then mixed with the starch obtained in Comparative Example 3 (the mass ratio of starch to lutein oil was 10:5).

[0063] (9) Comparison of nutritional enhancer 4 The same as nutrient enhancer 1, except that the V-type starch obtained in Example 1 is replaced with the starch obtained in Comparative Example 4. That is, Comparative nutrient enhancer 4 is: In the dark and at 35 ℃, lutein was added to soybean oil (the mass ratio of lutein to soybean oil was 0.4:100), stirred at 650 rpm for 30 min, and then centrifuged at 4500 rpm for 8 min. The resulting oil phase was lutein oil, which was then mixed with the starch obtained in Comparative Example 4 (the mass ratio of starch to lutein oil was 10:5).

[0064] (10) Comparison of nutritional enhancer 5 The difference between the comparative nutrient enhancer 5 and nutrient enhancer 1 is that the V-type starch obtained in Example 1 is not added. Therefore, comparative nutrient enhancer 5 is: Lutein was added to soybean oil (the mass ratio of lutein to soybean oil was 0.4:100) in the dark and at 35 ℃. After stirring at 650 rpm for 30 min, the mixture was centrifuged at 4500 rpm for 8 min. The resulting oil phase was lutein oil.

[0065] II. Oxidative stability of lutein lipids The oil and fat oxidation stability tester is mainly used to determine the oxidation stability of oils and fats under specific conditions. It can monitor and collect volatile oxides generated during the heating process. Since an increase in volatile oxides leads to an increase in conductivity, the oxidation status of the sample can be reflected by measuring the change in conductivity. A conductivity-time curve is plotted with time on the x-axis and conductivity on the y-axis. When the curve shows a clear inflection point, it represents the beginning of rapid oxidation of the sample. The time corresponding to this inflection point is the oxidation induction time. The oxidation induction time indicates that the sample can remain thermally oxidatively stable before this time point.

[0066] 0.5 g of nutrient enhancers 1-5 and control nutrient enhancers 1-5 were weighed and placed in an oil oxidation stability tester, heated to 100 °C under a constant air flow of 20 L / h, and the oxidation induction time was measured. The results are shown in Table 1.

[0067] Table 1

[0068] It is evident that the oxidation induction time of nutrient enhancers 1-5 is significantly longer than that of the comparative nutrient enhancers 1-5. That is, the oxidation stability of nutrient enhancers 1-5 is significantly better than that of the comparative nutrient enhancers 1-5. This indicates that the present invention uses low-cost materials such as starch, water, and ethanol, and specifically controls the dropping rate of ethanol to prepare V-shaped starch for encapsulating lutein oil, which can significantly improve the oxidation stability of lutein and is significantly better than the pregelatinized starch and porous starch commonly available on the market.

[0069] Test Example 3: Application of Nutritional Enhancers in the Preparation of Fermented Flour Products I. Preparation of Steamed Buns 1-5 and Comparative Steamed Buns 1-5 Mix 170 g wheat flour, 30 g nutrient enhancer 1-5 and control nutrient enhancer 1-5, 2.5 g yeast, 32 g white sugar, 2.5 g baking powder, 0.4 g salt and 85 g water. After kneading and shaping, let it rise at 38 ℃ and 75% relative humidity for 45 min to obtain dough 1-5 and control dough 1-5.

[0070] The dough was steamed at 100 ℃ for 7 minutes to obtain steamed buns 1-5 and control steamed buns 1-5.

[0071] Among them, dough 1-5 and steamed bun 1-5 are dough and steamed buns using nutrient enhancer 1-5, and comparative dough 1-5 and comparative steamed bun 1-5 are dough and steamed buns using comparative nutrient enhancer 1-5.

[0072] II. Observation of the surface morphology of steamed buns Observe the surface morphology of steamed buns 1-5 and the control steamed buns 1-5.

[0073] As can be seen, the surface of steamed buns 1-5 has a uniform color and no "oil spots", indicating that lutein is evenly distributed in steamed buns 1-5; while the color of the comparison steamed buns 1-4 is uneven in some areas, and the comparison steamed bun 5 has slight "oil spots", indicating that lutein is unevenly distributed in comparison steamed buns 1-5.

[0074] III. Determination of Lutein Content and Retention Rate in Steamed Buns After freeze-drying the steamed buns 1-5 and control steamed buns 1-5 separately for 48 h, they were pulverized and passed through a 40-mesh sieve. 4.0 g of the dried steamed bun powder was then weighed into a 250 mL Erlenmeyer flask with a ground glass stopper. 40 mL of distilled water and 60 mL of a petroleum ether / acetone mixture (volume ratio 1:1) were added. The flask was stoppered and magnetically stirred at 1000 r / pm for 20 min. After centrifugation, the upper organic phase was collected. The lower aqueous phase was extracted twice with 60 mL of the petroleum ether / acetone mixture (volume ratio 1:1) until the aqueous phase became colorless. The organic phases were combined, separated using a separatory funnel, and then rotary evaporated to dryness at 30 °C. The mixture was reconstituted with 15 mL of acetone, and the absorbance was measured at 460 nm. The lutein content (μg / g) in the dried steamed bun powder was calculated based on the lutein standard curve. The mass of lutein in the steamed bun was calculated using the formula: "Lutein mass in steamed bun (μg) = Lutein content in dried steamed bun powder × Dry basis mass of steamed bun". The lutein retention rate was then calculated using the formula: "Retention rate (%) = Lutein mass in steamed bun / Initial added lutein mass × 100%". The results are shown in Table 2.

[0075] Table 2

[0076] It is evident that the lutein retention rate of steamed buns 1-5 is significantly higher than that of the control steamed buns 1-5. That is, steamed buns using nutrient enhancer 1-5 can better retain lutein, indicating that using the V-type starch of the present invention to encapsulate lutein oil can significantly improve the oxidative stability of lutein, reduce its degradation, and thus improve its retention rate in fermented flour products, thereby enhancing the nutritional value of fermented flour products.

[0077] IV. Evaluation of color difference in steamed buns The color changes of steamed buns 1-5 and control steamed buns 1-5 before and after steaming were evaluated using a CR-8 colorimeter (i.e., dough 1-5 compared to steamed buns 1-5, and control dough 1-5 compared to control steamed buns 1-5). The chromaticity coordinates were L* (lightness / darkness), a* (redness / greenness), and b* (yellowness / blueness). The color changes before and after steaming were represented by ΔL*, Δa*, and Δb* values, and the standard formula was used. The total color difference (ΔE) was calculated, and the results are shown in Table 3.

[0078] Table 3

[0079] visible: (1) The color changes of the steamed buns before and after steaming showed the same trend of increasing brightness and decreasing redness and yellowness. This is related to the expansion of the steamed buns during fermentation and the degradation of lutein during the 100 ℃ high temperature process, which makes the color of the steamed buns lighter after steaming. (2) Steamed buns 1-5 E is significantly smaller than that of the comparative steamed buns 1-5. That is, the color difference of the steamed buns using nutritional enhancers 1-5 before and after steaming is significantly smaller than that of the steamed buns using the comparative nutritional enhancers 1-5. This indicates that using the V-type starch of the present invention to encapsulate lutein oil can significantly improve the oxidative stability of lutein, reduce its degradation, and thus improve its retention rate in fermented flour products, thereby enhancing the nutritional value of fermented flour products.

[0080] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing V-type starch, characterized in that, After gelatinizing the starch, ethanol was added dropwise at a flow rate of 40–60 mL / h at 85–95 °C, and the mixture was purified to obtain V-type starch.

2. The preparation method according to claim 1, characterized in that, The volume ratio of the gelatinized product to ethanol is 1:2 to 4.

3. V-type starch obtained by the method described in any one of claims 1 to 2.

4. The application of the V-type starch according to claim 3 in lutein-encapsulated oils.

5. The application according to claim 4, characterized in that, The method for preparing the lutein oil is as follows: after dissolving lutein in oil, the water and oil are separated, and the resulting oil phase is the lutein oil.

6. The application according to claim 5, characterized in that, The oil is one or more of soybean oil, peanut oil, corn oil, and sunflower seed oil.

7. The application according to claim 4, characterized in that, The mass ratio of V-type starch to lutein oil is 10:5-7.

8. A nutritional enhancer, characterized in that, It is obtained by encapsulating lutein oil in V-shaped starch as described in claim 3.

9. The use of the nutritional enhancer according to claim 8 in the preparation of fermented flour products.

10. A fermented dough product, characterized in that, Add the nutritional enhancer as described in claim 8.

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