Preparation method of low-GI bread crumbs

Abstract

The invention discloses a preparation method of low-GI bread crumbs, and relates to the technical field of food processing. The method comprises the following steps: by taking whole rye flour as a raw material, firstly carrying out heat-moisture treatment, and pre-modifying a starch structure by adjusting moisture and thermally processing; then the modified rye flour is mixed with water, salt and the like to prepare dough, and after fermentation and baking of sufficient gelatinization, core controllable retrogradation treatment is carried out, that is, storage is carried out for 48-72 hours at the temperature of 2-6 DEG C, so that formation of resistant starch is deeply promoted; and finally, performing low-temperature drying and crushing to obtain a finished product. Through systematic combination and synergistic interaction of raw materials and physical processes, the produced breadcrumbs are high in resistant starch content, low in glycemic index, rich in dietary fibers, crisp in taste and rich in flavor, and an innovative healthy food ingredient is provided for the market.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, specifically to a low-GI breadcrumbs and its preparation method. Background Technology

[0002] Breadcrumbs are a traditional food coating ingredient. Their basic production process typically uses wheat flour as the main raw material, involving kneading, fermentation, and baking to create bread dough. The bread dough is then dried, crushed, and sieved to obtain a pale yellow, uniformly sized crumbly product. Due to its unique crispy texture and golden color, breadcrumbs are widely used in the food industry and home cooking, often as a coating for fried foods (such as fried chicken cutlets, fried pork cutlets, and fried shrimp) and oven-baked foods (such as popcorn chicken and cheese sticks). As the "outer shell" of food, breadcrumbs primarily serve the following functions: First, they impart an appealing golden color and a crispy, crumbly texture to the product; second, during frying, they form an insulating layer, reducing the loss of moisture and flavor compounds from the inside of the food, resulting in a crispy exterior and tender interior; third, as a carrier, they can hold spices and seasonings, enriching the overall flavor.

[0003] However, traditional breadcrumbs have significant nutritional and health drawbacks. Their main ingredient is refined wheat flour, a high-carbohydrate, low-fiber food. During processing, the baking of the bread dough causes the starch to gelatinize fully, making traditional breadcrumbs a high-glycemic index (GI) food. When consumers eat foods coated with traditional breadcrumbs, the carbohydrates are rapidly digested and absorbed, causing sharp fluctuations in blood sugar levels. This is extremely detrimental to people with diabetes, insulin resistance, and the growing number of health-conscious consumers managing their blood sugar.

[0004] To improve the health benefits of traditional breadcrumbs, several solutions have emerged on the market. The most common approach is to partially or completely replace refined wheat flour with whole wheat flour to increase dietary fiber content. Another approach is to directly add bran or other types of dietary fiber (such as oat fiber). However, these methods all have significant drawbacks: firstly, they are simple "physical additions" that do not fundamentally change the digestible properties of starch, thus having limited effect on lowering the product's glycemic index; secondly, excessive addition of coarse fiber can severely damage the texture and flavor of breadcrumbs, resulting in a rough, hard texture and poor flavor, making it difficult for consumers to widely accept, and potentially affecting the crispness of the final fried or baked product. Therefore, developing a breadcrumb preparation method that can fundamentally reduce the rate of starch digestion while maintaining a good crisp texture and flavor has significant market value and technological importance. Summary of the Invention

[0005] To address the aforementioned problems, the purpose of this invention is to provide a method for preparing low-GI breadcrumbs. By combining raw material innovation with physical modification processes, the formation of resistant starch is systematically promoted, thereby producing breadcrumbs that are low in GI, high in dietary fiber, and have excellent taste and flavor.

[0006] To achieve the above objectives, the present invention first provides a method for preparing low-GI breadcrumbs, comprising the following steps: S1. Raw material pretreatment: Using whole rye flour as the main raw material, adjust its moisture content to 25%~35%, perform wet heat treatment and then dry to obtain modified rye flour; S2. Dough preparation: Mix the modified rye flour obtained in step S1 with water, yeast, salt and sugar, add it to a dough mixer and stir until the dough surface is smooth, so that the gluten is fully formed.

[0007] S3. First fermentation of dough: Place the kneaded dough in a fermentation environment with a temperature of 28-30℃ and a humidity of 75-85% for the first fermentation. Then, press the dough, deflate it, shape it and divide it into pieces. S4. Second fermentation of dough: The dough obtained in step S3 is placed in a fermentation box for a second fermentation. S5. Dough maturation: Place the dough that has been fermented in step S4 into an electrode maturation box for maturation and bake it into bread dough. S6. Controlled Reversion Process: Cool the bread dough obtained in step S5 and then perform a reversion process; S7. Crushing: The bread dough after the regeneration treatment in step S6 is put into a crusher for crushing and drying to obtain breadcrumbs.

[0008] In one embodiment of the present invention, in step S1, the moisture content is adjusted to 28%~32%.

[0009] In one embodiment of the present invention, in step S1, the damp heat treatment is performed at 100°C to 120°C for 30 to 60 minutes.

[0010] In one embodiment of the present invention, in step S1, the drying process involves reducing the moisture content of the modified rye flour to ≤14%. The drying method includes any one of the commonly used drying methods such as drying in an oven, hot air drying, and vacuum drying, preferably drying at 60~80°C.

[0011] In one embodiment of the present invention, in step S2, the amount of water added to the dough is 50-60% of the total mass of starch in the modified rye flour, the amount of yeast powder is 1-3% of the mass of the modified rye flour, the amount of salt is 1-2% of the mass of the modified rye flour, and the amount of sugar is 1-2% of the mass of the modified rye flour.

[0012] In one embodiment of the present invention, in step S2, inulin or resistant dextrin, accounting for 0.5% to 2% of the weight of the modified rye flour, may be added to the dough.

[0013] In one embodiment of the present invention, in step S2, the stirring is performed by alternating between low-speed stirring and high-speed stirring. The low-speed stirring is performed at 60-90 r / min for 4-6 minutes, and the high-speed stirring is performed at 300-400 r / min for 5-8 minutes. After that, the stirring is switched back to low speed (60-100 rpm) for 1-2 minutes to relax the dough. Finally, the stirring is switched back to high speed (300-400 rpm) for 2-4 minutes until the dough reaches a state of smooth surface and uniform texture.

[0014] In one embodiment of the present invention, in step S3, the fermentation time is 60-90 minutes, and the fermentation causes the dough volume to expand to 1.5-2 times its original size.

[0015] In one embodiment of the present invention, in step S4, the secondary fermentation is carried out at a temperature and humidity of 35~45°C for 8~12 minutes.

[0016] In one embodiment of the present invention, in step S5, the curing is electrode process curing, and the time is 10 minutes.

[0017] In one embodiment of the present invention, in step S6, the controlled regeneration is performed by storing the product in a low-temperature environment of 2-6°C for 6-24 hours.

[0018] In one embodiment of the present invention, in step S7, the drying involves evenly spreading the crushed wet breadcrumbs on a conveyor belt and drying them using a fluidized bed hot air drying device.

[0019] The present invention also provides a low-GI breadcrumb prepared according to the above method.

[0020] This invention also provides an application of low-GI breadcrumbs in food.

[0021] Beneficial effects: 1. This invention uses rye flour as raw material. The rye flour is first subjected to wet heat treatment, and then the prepared bread dough undergoes controlled deep retrogradation. By combining three key technical elements—raw material selection, raw material pretreatment, and post-retrogradation treatment—a significant synergistic effect is achieved, substantially reducing the GI value of the breadcrumbs. The wet heat treatment pre-stabilizes the starch structure, and the arabinoxylan in rye, together with the retrograded starch, constructs a "double digestive barrier," thereby fundamentally and significantly reducing the product's digestibility, resulting in a significantly lower GI value than traditional breadcrumbs.

[0022] 2. This invention primarily employs physical modification methods, requiring no chemical additives, aligning with the clean label trend. The final product is rich in dietary fiber and resistant starch derived from rye and process conversion, providing prebiotic benefits that promote gut health.

[0023] 3. This invention overcomes the drawback of simply adding coarse fiber, which results in a rough texture. Through process control, the resulting breadcrumbs have a natural dark brown color, a rich rye aroma, and crisp texture, satisfying consumers' dual needs for health and deliciousness.

[0024] 4. The method described in this invention has clear steps and well-defined key process parameters, making it easy to implement and control on the basis of existing food processing equipment, and has the potential for large-scale industrial production. Attached Figure Description

[0025] Figure 1 This is a process flow diagram of the GI breadcrumb preparation method of the present invention; Figure 2 The moisture content and oil absorption rate of the breadcrumbs prepared in Examples 1-6 and Comparative Examples 1-6 are shown. Detailed Implementation

[0026] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0027] The testing method involved in this invention: 1. Determination of the GI value of breadcrumbs in in vitro digestion experiments S1. Place 1g of sample into a beaker, add 3mL of phosphate buffer (0.1mol / L) and 1mL of amylase solution and shake well. Add 10mL of phosphate buffer (0.1mol / L), 6mL of sodium chloride solution (0.4g / L), and 0.05g of pepsin. Adjust the pH to 1.5 with hydrochloric acid. Stir at 37℃ for 30min. Add 10mL of phosphate buffer (0.1mol / L) and adjust the pH to 6.9 with sodium hydroxide. Then add 125μL of CaCl2·2H2O solution (1.5mM), 125μL of trypsin solution, and 400μL of amylase. Add distilled water to 50mL and incubate at 37℃ in a shaker for 120min. At 0, 15, 30, 45, 60, 90, and 120 min, 1 mL of sample was placed in a solution containing 4 mL of 95% ethanol (preheated to 60°C), the enzyme was inactivated by boiling water bath, and then the sample was naturally cooled. After centrifugation at 4000 r / min for 10 min, the supernatant was collected and the reducing sugar content was determined by the DNS reduction method.

[0028] S2. Pipette glucose standard solution into a test tube, add distilled water to make up to 1 mL, add 2 mL DNS, boil in a water bath for 2 min, cool to room temperature, add 12 mL distilled water and mix well, measure absorbance at 540 nm to determine the standard curve. S3. Take 1 mL of sample supernatant, add 2 mL of DNS, boil in a water bath for 2 min, cool to room temperature, add 12 mL of distilled water and mix well. Measure the absorbance at 540 nm and calculate the reducing sugar concentration; GI = area of ​​the sample digestion curve in 2 h / area of ​​glucose digestion curve in 2 h * 100.

[0029] 2. Sensory evaluation of the product Ten trained professionals were invited to conduct sensory evaluations of the product. Before scoring, the evaluators used warm water to test each indicator of the product according to the scoring method and criteria. After each evaluation, they used warm water to test the product again. After the evaluation, they wrote down their overall comments in the remarks, including those listed and those not listed in the product's sensory evaluation criteria.

[0030] Table 1 Product Sensory Evaluation Criteria

[0031] 3. Determination of moisture content: The moisture content of the sample was determined by the drying constant weight method.

[0032] 4. Determination of oil absorption rate: Weigh various breadcrumb samples and fry them in soybean oil at 165℃ for 15 min. Filter to remove oil, transfer the filter residue to oil-absorbing paper, replace the filter paper until no more oil is absorbed, and determine the mass of the filter residue.

[0033] Oil absorption rate = (mass of filter residue - mass of sample) / mass of sample × 100% Example 1: S1. Raw material pretreatment: Take 1000g of whole rye flour, spray it with purified water and mix it evenly, adjusting the moisture content to 30%. Place the moistened rye flour in a steamer and heat-treat it at 110℃ for 3 hours. After removing it, dry it in a 60℃ oven until the moisture content is 12%, obtaining modified rye flour.

[0034] S2. Dough Preparation and Maturation: Take 800g of the modified rye flour, 320g of water, 10g of yeast, 8g of salt, 10g of sugar, and 10g of inulin (1.25% of the rye flour weight), mix them together and add them to a dough mixer. Mix at alternating low and high speeds until the dough surface is smooth, allowing the gluten to fully develop. Let it rest and ferment at room temperature for 80 minutes, deflate the dough, and then divide it into round dough balls weighing 100g ± 2g. Ferment at 40℃ for 10 minutes to complete the final proofing. Then, use electrodes to mature the dough and maintain this state for 10 minutes.

[0035] S3. Controlled retrogradation treatment: Cool the bread dough obtained in step S5, and then place it in a low temperature environment of 4°C for 8 hours; S4. Crushing: Put the cooled bread dough into the crusher, crush it, and pass the debris through a 50-mesh sieve.

[0036] S5. Drying: The crushed wet breadcrumbs are evenly spread on the conveyor belt and dried by a fluidized bed hot air dryer at a temperature of 200℃ for 20 minutes.

[0037] Examples 2-5: The difference between Examples 2-5 and Example 1 lies in the different wet heat treatment parameters used to prepare the rye flour for breadcrumbs. Specific differences are shown in Table 2. Table 2. Experimental parameters of wet heat treatment of rye flour in Examples 2-5

[0038] Example 6: A process for preparing breadcrumbs, the difference between this embodiment and Embodiment 1 is that the cooling and regeneration time in step S3 is 4 hours.

[0039] Comparative Example 1: The difference between Comparative Example 1 and Example 1 is that rye flour was replaced with ordinary refined wheat flour, and bread dough was made according to the method of Example 1 without undergoing wet heat treatment and retrogradation. After maturation, the dough was cooled at room temperature for 8 hours and then dried and pulverized to make breadcrumbs.

[0040] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that rye flour was replaced with ordinary refined wheat flour. After the bread dough was prepared and cooked, it was cooled at room temperature and then dried and pulverized to make breadcrumbs.

[0041] Comparative Example 3 The difference between Comparative Example 3 and Example 1 is that Comparative Example 3 does not undergo wet heat treatment and retrogradation treatment. Instead, bread dough is prepared according to the method of Example 1, matured, cooled at room temperature, and then dried and pulverized to make breadcrumbs.

[0042] Comparative Example 4 The difference between Comparative Example 4 and Example 1 is that only wet heat treatment was performed, followed by conventional cooling after aging, without retrogradation treatment.

[0043] Comparative Example 5 The difference between Comparative Example 5 and Example 1 is that Comparative Example 5 does not undergo damp heat treatment, but undergoes the same retrogradation treatment as Example 1.

[0044] Comparative Example 6 The difference between Comparative Example 6 and Example 1 is that the regeneration treatment time was changed and extended to 24 hours.

[0045] Table 3 shows the glycemic index (GI) values ​​of the breadcrumbs in Examples 1-5 and Comparative Examples 1-5. As can be seen from Table 1, compared to Comparative Example 1, the rye flour in Comparative Example 3, due to its higher dietary fiber content, has a significantly lower baseline glycemic index (GI) (GI=67) than refined wheat flour (GI=76). According to the internationally accepted scientific consensus upon which the "GB 28050-2011 National Food Safety Standard for General Rules for Nutrition Labelling of Prepackaged Foods" is based, a food with a glycemic index (GI) value ≤55 can be considered a "low GI food." The data from Comparative Example 3 clearly shows that using only rye flour as a raw material results in a product with a GI value still within the medium-high GI range of 68, failing to meet the standard for low GI foods.

[0046] This invention selects whole grain raw materials with health potential and transforms them into functional food ingredients with a clear low GI label through physical modification rather than chemical addition. Analysis of data from Comparative Examples 3-5 and Example 1 shows that while single methods of wet heat treatment (Comparative Example 4, GI=61) or controlled retrogradation treatment (Comparative Example 5, GI=63) can improve the indicators to some extent, the improvement effect is limited and neither can achieve a fundamental breakthrough of a GI value ≤55. However, this invention, by using rye flour as raw material and combining wet heat treatment and controlled retrogradation treatment, significantly reduced the GI value of breadcrumbs in Example 1 from 67 in Comparative Example 1 to 51, a reduction of 23.9%. This reduction has clear physiological significance in nutrition and can bring significant postprandial blood sugar stability and health benefits to consumers. The reduction rate of wet heat treatment alone was 9%, and the reduction rate of controlled retrogradation treatment alone was 6%, both significantly lower than the reduction rate in Example 1, indicating that wet heat treatment and controlled retrogradation treatment have a synergistic effect in reducing the GI value of breadcrumbs.

[0047] The temperature and time parameters of moist heat treatment also significantly affect the digestibility of breadcrumbs. Specifically, a comparative analysis of Examples 1 and 2-5 shows that moist heat treatment (HMT) is most effective at 110°C and 30% moisture. Under these conditions, HMT effectively induces the deconstruction and recombination of starch (especially amylose) molecules, making the amorphous region structure more compact and thus reducing the susceptibility of amylase to attack it. Excessively high treatment temperatures (such as in Example 5) may lead to undesirable caramelization or degradation of starch, thereby impairing its ability to form ordered resistant starch crystals as a precursor. Therefore, the optimized moist heat treatment creates an ideal precursor structure for the subsequent controlled retrogradation step. The two work synergistically to more effectively promote the formation of resistant starch, ultimately achieving the comprehensive goal of reducing the product's glycemic index (GI), enhancing health benefits, and improving edible quality.

[0048] In addition to the wet heat treatment, the time of the retrogradation treatment also has a significant impact on the GI value. When the retrogradation is carried out in a short time (4~22h), the breadcrumbs will have a low GI value. As the retrogradation time increases, when the retrogradation time reaches or exceeds 24h, the GI value of the breadcrumbs increases significantly. For example, the GI value of Comparative Example 6 has exceeded 55.

[0049] Table 3. Digestibility characteristics of breadcrumbs under different treatment conditions

[0050] Table 4 Sensory properties of breadcrumbs under different treatment conditions

[0051] Table 4 presents the sensory evaluation data for breadcrumbs. As can be seen from Table 4, the sensory evaluation score of the breadcrumbs prepared by replacing ordinary refined wheat flour with rye flour decreased significantly (see Comparative Examples 1 and 3). However, the present invention, by combining wet heat treatment and controlled retrogradation treatment, significantly improved the sensory evaluation score. That is, the combination of wet heat treatment and controlled retrogradation treatment can improve consumers' acceptance of breadcrumbs, thereby promoting the application of rye flour in breadcrumb preparation.

[0052] Figure 2 The moisture content and oil absorption rate of the breadcrumbs prepared in Examples 1-6 and Comparative Examples 1-6 are given. Figure 2 As can be seen, the oil absorption rate of Example 1 is as low as 32.5%, a significant reduction compared to Comparative Example 1 using the traditional process. This effect is consistent with the mechanism of blocking oil penetration in existing technologies by constructing a "dense tissue structure." The outstanding inventiveness of this invention lies in the fact that this dense structure is not obtained through complex exogenous means such as adding exogenous colloids, emulsifiers, or relying on high-intensity extrusion, but rather through the directional regulation of the starch recrystallization and dietary fiber network reconstruction of the raw materials themselves. The technical path is cleaner and simpler, in line with the development trend of clean label foods. Comparative Example 3 did not use wet heat treatment and controlled retrogradation treatment, Comparative Example 4 only used wet heat treatment, and Comparative Example 5 only used controlled retrogradation treatment. Although Comparative Examples 4 and 5 can reduce the oil absorption rate, the reduction effect is more significant. For example, the oil absorption rate of Comparative Example 4 is 36%, a decrease of 6.5%, and the oil absorption rate of Comparative Example 5 is 37%, a decrease of 7.5%. Compared to Comparative Examples 4 and 5, Example 1 showed a much greater decrease, indicating that wet heat treatment and controlled retrogradation treatment also had a synergistic effect in reducing oil absorption rate.

[0053] Meanwhile, the moisture content of Example 1 (6.0%) was also significantly lower than that of all comparative examples. This indicates that the three-dimensional network structure formed by the synergistic process has a stronger internal water-binding capacity, resulting in a product with low final moisture content and high stability. Lower moisture content helps inhibit microbial growth, extends product shelf life, and, in frying applications, contributes to a crispier texture.

[0054] Through process control, this invention not only effectively reduces the oil absorption rate of breadcrumbs and increases their moisture content, but also blends flavor into the rich aroma of bread. Furthermore, the formula used in this invention contains no artificial additives, making it healthy and nutritious, meeting people's demand for low-calorie, healthy foods. Therefore, the low-GI breadcrumbs prepared by this invention have high market application value.

[0055] The embodiments provided above are not intended to limit the scope of the invention, nor are the described steps intended to limit the order of execution. Any obvious modifications made to the invention by those skilled in the art based on existing common knowledge also fall within the scope of protection defined by the claims.

Claims

1. A method of preparing a low GI bran comprising, The method comprises the following steps: S1, raw material pretreatment: taking whole rye flour as the main raw material, adjusting the moisture content to 25%-35%, and then drying after wet heat treatment to obtain modified rye flour; S2, dough preparation: mixing the modified rye flour obtained in step S1 with water, yeast powder, salt and sugar in a mixer, and stirring until the surface of the dough is smooth to make the gluten fully formed. S3, first fermentation of the dough: placing the mixed dough in a fermentation environment with a temperature of 28-30℃ and a humidity of 75-85% for first fermentation, and then pressing, exhausting, shaping and dividing into dough blocks; S4, second fermentation of the dough: sending the dough blocks obtained in step S3 into a fermentation box for second fermentation; S5, maturation of the dough: placing the dough fermented in step S4 into an electrode maturation box for maturation to obtain bread loaves; S6, controllable retrogradation treatment: cooling the bread loaves obtained in step S5, and then performing retrogradation treatment; S7, crushing: placing the bread loaves after the retrogradation treatment in step S6 into a crusher for crushing, and drying to obtain bread crumbs.

2. The production method according to claim 1, characterized by, In step S1, the moisture content is adjusted to 28%-32%, and the wet heat treatment is performed at 100℃-120℃ for 30-60 minutes.

3. The production method according to claim 1, characterized by, In step S1, the drying is to reduce the moisture content of the modified rye flour to ≤14%, and the drying mode includes any one of drying in an oven, hot air drying and vacuum drying.

4. The method of claim 1, wherein, In step S2, the amount of water added in the dough is 50-60% of the total mass of starch in the modified rye flour, the amount of yeast powder is 1-3% of the mass of the modified rye flour, the amount of salt is 1-2% of the mass of the modified rye flour, and the amount of sugar is 1-2% of the mass of the modified rye flour.

5. The preparation method according to claim 1, characterized in that, In step S2, 0.5%-2% of inulin or resistant dextrin by weight of the modified rye flour can also be added to the dough.

6. The method of claim 1, wherein, In step S3, the first fermentation is performed for 60-90 minutes, and the volume of the dough is expanded to 1.5-2 times of the original volume.

7. The preparation method according to claim 1, characterized in that, In step S4, the second fermentation is performed at a temperature of 35-45℃ and a humidity for 8-12 minutes.

8. The method of claim 1, wherein, In step S6, the controllable retrogradation is performed by storing at a low temperature of 2-6℃ for 6-24 hours.

9. The low GI bread crumbs prepared by the method according to any one of claims 1-8.

10. The use of the low GI bread crumbs according to claim 9 in food.

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