Steam explosion improved grain processing by-product and application of steam explosion improved grain processing by-product in preparation of low-GI coarse grain biscuits

Abstract

The invention belongs to the field of food processing and safety, and provides a steam explosion improved grain processing byproduct and application thereof in preparation of low-GI coarse grain biscuits. The triticale bran is pretreated through a steam explosion (SE) technology, the content of soluble dietary fibers is increased by 53.63% under the conditions of 1.0 MPa and 90 s, and the content of free phytochemicals and the oxidation resistance are the highest; the color of the wheat bran is changed into dark brown / dark brown from light brown, the interior of the wheat bran is of a porous honeycomb structure, the water binding capacity and the swelling property are improved, and an infrared spectrum shows that methyl and methylene structures are damaged and tissues are loosened; the fatty acid value is remarkably reduced, the storage period and the shelf life are effectively prolonged, comprehensive improvement of nutritional ingredients, physicochemical properties, biological activity and storage characteristics is achieved, and remarkable technical advantages are achieved.

Description

Technical Field

[0001] This invention belongs to the field of food processing and safety, and specifically relates to a method for improving the quality of grain processing by-products based on steam explosion pretreatment. Background Technology

[0002] Dietary fiber, known as the "seventh nutrient," has important physiological functions, such as lowering blood sugar, regulating blood lipids, aiding weight loss, and reducing the risk of chronic diseases. Although wheat bran can be used as a food ingredient and has health-promoting effects, its use in food processing still presents technical and sensory challenges. Numerous studies have shown that the high content of insoluble substances in wheat bran results in poor swelling properties, making it difficult to apply in food. Therefore, pretreatment is necessary to mitigate the adverse effects of wheat bran on the final product.

[0003] In recent years, steam explosion technology has been applied to the food industry, making it possible to improve the use value and economic value of grain processing by-products such as wheat bran. He Xiaoqin et al. used steam explosion to pre-treat and modify buckwheat bran, while Li et al. used steam explosion to physically modify soybean residue. Both studies showed that steam explosion can significantly reduce insoluble substances, significantly increase soluble substances, and improve the processing suitability of raw materials. Cheng et al. found that steam explosion is beneficial for the release of phenolic substances and enhances the antioxidant properties of red beans. Utilizing steam explosion to improve the quality and functional properties of grain processing by-products such as wheat bran, and applying it to the development of products such as biscuits, is of great significance for contributing to "saving grain and reducing waste" and "Healthy China." Summary of the Invention

[0004] To address the aforementioned technical problems, this invention proposes a steam-explosion-modified grain processing byproduct and its application in the preparation of low-GI whole-grain biscuits. This method utilizes steam explosion to pretreat grain processing byproducts such as black wheat bran. The resulting black wheat bran exhibits significant improvements in nutritional components, physicochemical properties, nutritional quality, bioactive substances, antioxidant activity, and storage characteristics. The sensory quality of the low-GI whole-grain biscuits prepared using this bran is significantly improved, with a GI value below 55.

[0005] The technical solution of this invention is: A steam explosion-modified grain processing byproduct and its application in the preparation of low-GI whole grain biscuits includes the following steps: Grain processing byproducts are taken, steam is introduced, and steam is used to explode the product for 75-110 seconds at a pressure of 0.8-1.2 MPa. The product is then dried at 45-60℃ and pulverized through an 80-mesh sieve to obtain improved black wheat bran.

[0006] Preferably, the conditions for steam explosion are a pressure of 1.0 MPa and a time of 90 s.

[0007] Preferably, the drying conditions are 50°C.

[0008] Preferably, the grain processing by-product is selected from any one of black wheat bran, oat bran, corn bran, and buckwheat bran.

[0009] Another aspect of the present invention is the application of the improved grain processing by-product obtained by the above method in the preparation of low-GI products.

[0010] A low-GI whole-grain biscuit is provided, comprising the following ingredients based on 100% low-gluten flour, 50% butter, 40% shortening, 20% egg white, 17.53% modified grain processing by-products, 5.07% resistant dextrin, 30% maltitol, and 12.15% inulin.

[0011] The present invention has the following advantages and effects compared with the prior art: (1) Steam explosion (SE) treatment can effectively convert insoluble dietary fiber in black wheat bran into soluble dietary fiber and promote the release of bioactive components, thereby improving its antioxidant activity. The modification effect is most significant under the SE treatment conditions of 1.0 MPa + 90 s, under which the soluble dietary fiber content of black wheat bran increases by 53.63%, and it has the highest content of free phytochemicals and antioxidant activity. (2) Compared with unmodified black wheat bran, SE black wheat bran changes its surface color from light brown to dark brown or dark brown due to Maillard reaction and caramel reaction. Its internal structure becomes porous and rough, even honeycomb structure. Its water holding capacity and swelling capacity show an upward trend. According to infrared spectroscopy analysis, the reason may be that SE can destroy the structure of methyl and methylene groups, reduce the internal structural strength, and make the bran structure loose. (3) Compared with unmodified black wheat bran, the fatty acid value of SE black wheat bran was significantly reduced (P<0.05), and steam explosion can prolong the storage period and shelf life of black wheat bran; (4) The biscuits prepared using the modified wheat bran of the present invention have a moisture content of 2.12% and a fat content of 20.21%, and also have low GI properties. Attached Figure Description

[0012] Figure 1 The effect of steam explosion on the dietary fiber content of wheat bran; Figure 2 The effect of steam explosion on the fatty acid content of wheat bran; Figure 3 The effect of steam explosion on the antioxidant properties of wheat bran; Figure 4 The effect of steam explosion on functional groups in wheat bran; Figure 5 The effects of steam explosion on the internal structure of wheat bran were investigated. Example a represents Example 1 (0.5 MPa + 30 s); Example b represents Example 2 (0.5 MPa + 60 s); Example c represents Example 3 (0.5 MPa + 90 s); Example d represents Example 4 (1.0 MPa + 30 s); Example e represents Example 5 (1.0 MPa + 60 s); Example f represents Example 6 (1.0 MPa + 90 s); Example g represents Example 7 (1.5 MPa + 30 s); Example h represents Example 8 (1.5 MPa + 60 s); Example i represents Example 9 (1.5 MPa + 90 s); and Control group 10 (untreated). Figure 6 The effect of wheat bran addition on sensory scores; Figure 7 The effect of wheat bran addition on the hardness and crispness of biscuits; Figure 8 The effect of resistant dextrin addition on sensory scores; Figure 9 The effect of resistant dextrin addition on the hardness and crispness of biscuits; Figure 10 The effect of maltitol addition on sensory scores; Figure 11 The effect of maltitol addition on the hardness and crispness of biscuits; Figure 12 The effect of inulin addition on sensory scores; Figure 13 The effect of inulin addition on the hardness and crispness of biscuits; Figure 14 The response surface between various influencing factors; Figure 15 This is a graph showing the relationship between starch hydrolysis rate and time. Detailed Implementation

[0013] To enable those skilled in the art to better understand the present invention, the present invention will now be further described in conjunction with specific embodiments.

[0014] Examples 1-9: Steam explosion (SE) based method for pretreating black wheat bran: Black wheat bran was placed in the material hopper of the blasting device. After steam was introduced, blasting was performed at pressures of 0.5 MPa, 1.0 MPa, and 1.5 MPa and pressure holding times of 30 s, 60 s, and 90 s. Black wheat bran that was not blasted was used as a control. The processed black wheat bran was dried at 50℃, pulverized through an 80-mesh sieve, and sealed for later use. The specific sample processing is shown in Table 1.

[0015] Table 1 Sample Examples Example Processing conditions Example 1 0.5 MPa + 30 s Example 2 0.5 MPa + 60 s Example 3 0.5 MPa + 90 s Example 4 1.0 MPa + 30 s Example 5 1.0 MPa + 60 s Example 6 1.0 MPa + 90 s Example 7 1.5 MPa + 30 s Example 8 1.5 MPa + 60 s Example 9 1.5 MPa + 90 s control group 10 Untreated black wheat bran

[0016] Experimental Example 1: Nutritional Index Detection (1) Routine nutrient content detection: Protein content: determined according to GB 5009.5-2016 Kjeldahl method; Dietary fiber content: determined according to GB 5009.88-2014; Fat content: determined according to GB 5009.6-2016 Soxhlet extraction method; Ash content: determined according to GB 5009.4-2016; Moisture content: determined according to GB 5009.3-2016 direct drying method.

[0017] Table 2. Effects of steam explosion on the content of conventional nutrients in wheat bran. Example Protein (g / 100g) Fat (g / 100g) Ash content (g / 100g) Moisture content (g / 100g) 1 <![CDATA[20.34±0.07 a ]]> <![CDATA[4.80±0.14 a ]]> <![CDATA[5.80±0.42 a ]]> <![CDATA[2.87±0.55 a ]]> 2 <![CDATA[20.01±0.06 c ]]> <![CDATA[4.70±0.14 a ]]> <![CDATA[5.70±0.14 a ]]> <![CDATA[3.14±0.89 a ]]> 3 <![CDATA[19.99±0.01 c ]]> <![CDATA[4.80±0.28 a ]]> <![CDATA[5.60±0.14 a ]]> <![CDATA[3.01±0.83 a ]]> 4 <![CDATA[20.29±0.07 a ]]> <![CDATA[4.50±0.14 a ]]> <![CDATA[5.80±0.14 a ]]> <![CDATA[2.80±0.47 a ]]> 5 <![CDATA[19.95±0.01 c ]]> <![CDATA[4.70±0.28 a ]]> <![CDATA[5.80±0.14 a ]]> <![CDATA[3.07±0.74 a ]]> 6 <![CDATA[20.23±0.03 ab ]]> <![CDATA[4.90±0.14 a ]]> <![CDATA[5.70±0.14 a ]]> <![CDATA[3.00±0.84 a ]]> 7 <![CDATA[20.07±0.13 bc ]]> <![CDATA[4.70±0.14 a ]]> <![CDATA[5.70±0.14 a ]]> <![CDATA[2.92±0.51 a ]]> 8 <![CDATA[19.99±0.01 c ]]> <![CDATA[4.80±0.14 a ]]> <![CDATA[5.70±0.28 a ]]> <![CDATA[2.80±0.73 a ]]> 9 <![CDATA[20.19±0.04 ab ]]> <![CDATA[4.60±0.14 a ]]> <![CDATA[5.70±0.14 a ]]> <![CDATA[2.91±0.75 a ]]> 10 <![CDATA[19.99±0.15 c ]]> <![CDATA[5.10±0.14 a ]]> <![CDATA[4.40±0.14 b ]]> <![CDATA[2.78±0.10 a ]]>

[0018] Note: Different letters in the same column indicate significant differences between data. P <0.05). The same applies below.

[0019] Table 2 shows the routine nutritional composition analysis of unmodified black wheat bran and SE black wheat bran. Compared with unmodified bran, SE black wheat bran has higher protein, ash, and moisture content, while its fat content is lower. The changes in soluble and insoluble dietary fiber content in black wheat bran are also shown in Table 2. Figure 1 As can be seen, the insoluble dietary fiber content in SE black wheat bran decreased, while the soluble dietary fiber content increased. Compared to other examples, Example 6 (1.0 MPa + 90 s) had the highest soluble dietary fiber content. P <0.05), with a content of 8.88 g / 100g, which is 1.54 times that of unmodified black wheat bran. The increased soluble dietary fiber content of SE black wheat bran may be related to the thermochemical reaction that occurs during the steam explosion cooking stage, which leads to the conversion of insoluble dietary fiber into soluble dietary fiber, and the subsequent instantaneous depressurization stage, which breaks down cell walls and promotes the release of soluble components.

[0020] (2) Mineral element content detection Four mineral elements (calcium, iron, zinc, and selenium) were selected and determined according to GB 5009.268-2016.

[0021] Table 3. Effects of steam explosion on the mineral element content of wheat bran Example Selenium (mg / kg) Calcium (mg / 100g) Iron (mg / 100g) Zinc (mg / 100g) 1 <![CDATA[0.14±0.01 b ]]> <![CDATA[165.95±3.32 a ]]> <![CDATA[12.05±0.35 bc ]]> <![CDATA[8.93±0.18 c ]]> 2 <![CDATA[0.15±0.01 b ]]> <![CDATA[168.35±4.03 a ]]> <![CDATA[12.40±0.56 abc ]]> <![CDATA[9.26±0.30 ab ]]> 3 <![CDATA[0.15±0.01 b ]]> <![CDATA[166.80±5.23 a ]]> <![CDATA[12.10±0.85 bc ]]> <![CDATA[9.32±0.37 ab ]]> 4 <![CDATA[0.16±0.01 b ]]> <![CDATA[164.00±9.19 a ]]> <![CDATA[12.20±0.14 abc ]]> <![CDATA[9.77±0.33 a ]]> 5 <![CDATA[0.17±0.01 b ]]> <![CDATA[167.85±0.35 a ]]> <![CDATA[13.15±0.49 ab ]]> <![CDATA[9.86±0.62 a ]]> 6 <![CDATA[0.21±0.01 a ]]> <![CDATA[173.20±0.14 a ]]> <![CDATA[13.30±0.56 a ]]> <![CDATA[9.81±0.55 a ]]> 7 <![CDATA[0.20±0.01 a ]]> <![CDATA[169.05±8.55 a ]]> <![CDATA[11.75±0.35 c ]]> <![CDATA[9.78±0.18 a ]]> 8 <![CDATA[0.18±0.01 a ]]> <![CDATA[159.95±1.48 a ]]> <![CDATA[12.05±0.49 bc ]]> <![CDATA[9.37±0.13 ab ]]> 9 <![CDATA[0.17±0.01 b ]]> <![CDATA[165.85±4.03 a ]]> <![CDATA[11.85±0.21 c ]]> <![CDATA[9.34±0.22 ab ]]> 10 <![CDATA[0.12±0.01 c ]]> <![CDATA[159.35±9.26 a ]]> <![CDATA[11.40±0.14 c ]]> <![CDATA[8.77±0.08 c ]]>

[0022] This experiment determined the content of four mineral elements (selenium, calcium, iron, and zinc) in black wheat bran before and after modification, and the results are shown in Table 3. Among the four elements, calcium had the highest content (159.35–173.20 mg / 100g), significantly higher than the content of selenium, iron, and zinc. Iron was the next highest, with a content of 11.40–13.30 mg / 100g. After steam explosion treatment, the content of all four mineral elements in the black wheat bran increased to varying degrees. In Example 6 (1.0 MPa + 90 s), the zinc content (9.81 mg / 100g) was slightly lower than that in Example 5 (9.86 mg / 100g), while the selenium (0.21 mg / kg), calcium (173.20 mg / 100g), and iron (13.30 mg / 100g) contents all reached their highest values.

[0023] (3) Amino acid content detection The content of 17 amino acids was determined according to GB 5009.124-2016. Amino acid quality analysis was performed by comparing the protein profile with the WHO / FAO recommended model: Amino Acid Score (AAS), Essential Amino Acid Index (EAAI), and Biological Value (BV).

[0024] Table 4. Effect of steam explosion on amino acid content in wheat bran amino acids 1 2 3 4 5 6 7 8 9 10 Leucine <![CDATA[12.87±0.06 a ]]> <![CDATA[13.49±0.06 a ]]> <![CDATA[12.68±0.06 a ]]> <![CDATA[13.36±0.06 a ]]> <![CDATA[13.45±0.06 a ]]> <![CDATA[13.31±0.06 a ]]> <![CDATA[12.61±0.06 a ]]> <![CDATA[13.54±0.06 a ]]> <![CDATA[12.98±0.06 a ]]> <![CDATA[12.82±0.06 a ]]> Isoleucine <![CDATA[2.95±0.02 a ]]> <![CDATA[3.05±0.01 a ]]> <![CDATA[2.89±0.02 a ]]> <![CDATA[3.05±0.01 a ]]> <![CDATA[3.06±0.02 a ]]> <![CDATA[2.99±0.06 a ]]> <![CDATA[2.86±0.01 a ]]> <![CDATA[3.13±0.01 a ]]> <![CDATA[2.86±0.01 a ]]> <![CDATA[2.96±0.01 a ]]> threonine <![CDATA[6.13±0.02 a ]]> <![CDATA[6.26±0.02 a ]]> <![CDATA[6.02±0.02 a ]]> <![CDATA[6.36±0.02 a ]]> <![CDATA[6.40±0.01 a ]]> <![CDATA[6.26±0.02 a ]]> <![CDATA[5.94±0.02 a ]]> <![CDATA[6.39±0.02 a ]]> <![CDATA[6.14±0.02 a ]]> <![CDATA[5.81±0.02 a ]]> Lysine <![CDATA[5.30±0.01 cd ]]> <![CDATA[6.24±0.0 b ]]> <![CDATA[6.93±0.01 a ]]> <![CDATA[6.51±0.01 b ]]> <![CDATA[5.64±0.01 c ]]> <![CDATA[7.14±0.01 a ]]> <![CDATA[6.97±0.01 a ]]> <![CDATA[4.98±0.01 d ]]> <![CDATA[3.94±0.01 f ]]> <![CDATA[4.53±0.01 e ]]> Methionine <![CDATA[2.18±0.01 bc ]]> <![CDATA[2.11±0.01 bc ]]> <![CDATA[2.11±0.01 bc ]]> <![CDATA[2.23±0.01 ab ]]> <![CDATA[2.39±0.01 a ]]> <![CDATA[2.07±0.01 bc ]]> <![CDATA[1.95±0.01 c ]]> <![CDATA[2.46±0.01 a ]]> <![CDATA[2.44±0.01 a ]]> <![CDATA[2.25±0.01 ab ]]> Phenylalanine <![CDATA[7.09±0.06 a ]]> <![CDATA[7.46±0.05 a ]]> <![CDATA[7.01±0.05 a ]]> <![CDATA[7.46±0.05 a ]]> <![CDATA[7.40±0.06 a ]]> <![CDATA[7.42±0.05 a ]]> <![CDATA[7.36±0.05 a ]]> <![CDATA[7.80±0.06 a ]]> <![CDATA[7.64±0.05 a ]]> <![CDATA[7.51±0.05 a ]]> Valine <![CDATA[7.67±0.03 a ]]> <![CDATA[7.84±0.03 a ]]> <![CDATA[7.46±0.03 a ]]> <![CDATA[7.87±0.03 a ]]> <![CDATA[8.04±0.03 a ]]> <![CDATA[7.69±0.04 a ]]> <![CDATA[7.27±0.03 a ]]> <![CDATA[8.04±0.03 a ]]> <![CDATA[7.64±0.03 a ]]> <![CDATA[7.65±0.03 a <!-- 4 -->]]> alanine <![CDATA[8.29±0.03 cde ]]> <![CDATA[8.59±0.03 abcd ]]> <![CDATA[8.35±0.02 bcde ]]> <![CDATA[8.74±0.02 abc ]]> <![CDATA[8.94±0.02 a ]]> <![CDATA[8.67±0.02 abcd ]]> <![CDATA[7.85±0.02 e ]]> <![CDATA[8.89±0.03 ab ]]> <![CDATA[8.63±0.02 abcd ]]> <![CDATA[8.14±0.02 de ]]> Serine <![CDATA[7.91±0.01 e ]]> <![CDATA[8.12±0.01 d ]]> <![CDATA[8.26±0.01 cd ]]> <![CDATA[8.70±0.01 a ]]> <![CDATA[8.80±0.01 a ]]> <![CDATA[8.67±0.01 ab ]]> <![CDATA[8.16±0.01 d ]]> <![CDATA[8.86±0.01 a ]]> <![CDATA[8.48±0.01 bc ]]> <![CDATA[7.60±0.01 f ]]> Aspartic acid <![CDATA[11.95±0.04 de ]]> <![CDATA[12.98±0.03 bc ]]> <![CDATA[13.83±0.03 a ]]> <![CDATA[13.64±0.04 ab ]]> <![CDATA[13.78±0.03 a ]]> <![CDATA[14.22±0.03 a ]]> <![CDATA[12.58±0.03 cd ]]> <![CDATA[13.48±0.03 ab ]]> <![CDATA[12.52±0.03 cd ]]> <![CDATA[11.43±0.03 e ]]> glycine <![CDATA[9.84±0.01 e ]]> <![CDATA[9.86±0.01 de ]]> <![CDATA[9.77±0.01 e ]]> <![CDATA[10.30±0.01 c ]]> <![CDATA[10.61±0.01 ab ]]> <![CDATA[10.14±0.01 cd ]]> <![CDATA[9.14±0.01 g ]]> <![CDATA[10.70±0.01 a ]]> <![CDATA[10.38±0.01 bc ]]> <![CDATA[9.47±0.01 f ]]> Arginine <![CDATA[9.70±0.03 e ]]> <![CDATA[11.13±0.02 c ]]> <![CDATA[11.84±0.02 ab ]]> <![CDATA[11.43±0.02 bc ]]> <![CDATA[10.38±0.02 d ]]> <![CDATA[12.19±0.03 a ]]> <![CDATA[11.02±0.02 c ]]> <![CDATA[9.74±0.01 e ]]> <![CDATA[7.92±0.02 c ]]> <![CDATA[8.93±0.02 f ]]> Histidine <![CDATA[5.01±0.01 bc ]]> <![CDATA[4.76±0.01 cd ]]> <![CDATA[5.08±0.01 abc ]]> <![CDATA[5.38±0.01 a ]]> <![CDATA[5.35±0.01 ab ]]> <![CDATA[5.20±0.01 ab ]]> <![CDATA[4.62±0.01 d ]]> <![CDATA[5.38±0.01 a ]]> <![CDATA[5.09±0.01 abc ]]> <![CDATA[4.57±0.01 d ]]> Cystine <![CDATA[0.00±0.00 e ]]> <![CDATA[0.38±0.00 c ]]> <![CDATA[0.21±0.00 d ]]> <![CDATA[0.05±0.00 e ]]> <![CDATA[0.37±0.00 c ]]> <![CDATA[0.86±0.01 a ]]> <![CDATA[0.43±0.00 c ]]> <![CDATA[0.60±0.00 b ]]> <![CDATA[0.37±0.00 c ]]> <![CDATA[0.36±0.00 c ]]> proline <![CDATA[12.30±0.07 a ]]> <![CDATA[12.88±0.07 a ]]> <![CDATA[12.07±0.07 a ]]> <![CDATA[13.31±0.07 a ]]> <![CDATA[12.88±0.07 a ]]> <![CDATA[12.83±0.07 a ]]> <![CDATA[13.25±0.07 a ]]> <![CDATA[13.22±0.07 a ]]> <![CDATA[13.14±0.07 a ]]> <![CDATA[12.60±0.07 a ]]> glutamic acid <![CDATA[35.86±0.04 e ]]> <![CDATA[37.45±0.04 d ]]> <![CDATA[37.56±0.04 d ]]> <![CDATA[40.11±0.04 bc ]]> <![CDATA[40.63±0.04 ab ]]> <![CDATA[40.43±0.04 abc ]]> <![CDATA[39.68±0.04 c ]]> <![CDATA[41.22±0.04 a ]]> <![CDATA[39.82±0.04 bc ]]> <![CDATA[35.84±0.04 e ]]> Tyrosine <![CDATA[3.89±0.02 a ]]> <![CDATA[4.05±0.02 a ]]> <![CDATA[3.97±0.02 a ]]> <![CDATA[4.11±0.02 a ]]> <![CDATA[4.11±0.02 a ]]> <![CDATA[4.11±0.02 a ]]> <![CDATA[4.13±0.02 a ]]> <![CDATA[4.24±0.02 a ]]> <![CDATA[4.06±0.02 a ]]> <![CDATA[3.97±0.02 a ]]> TAA <![CDATA[148.97±0.45 b ]]> <![CDATA[156.63±0.46 ab ]]> <![CDATA[156.03±0.45 ab ]]> <![CDATA[162.62±0.45 a ]]> <![CDATA[162.23±0.45 a ]]> <![CDATA[164.20±0.47 a ]]> <![CDATA[155.83±0.31 ab ]]> <![CDATA[162.65±0.46 a ]]> <![CDATA[154.04±0.45 ab ]]> <![CDATA[146.46±0.45 b ]]> EAA <![CDATA[48.10±0.22 a ]]> <![CDATA[50.50±0.23 a ]]> <![CDATA[49.06±0.23 a ]]> <![CDATA[50.95±0.23 a ]]> <![CDATA[50.50±0.22 a ]]> <![CDATA[51.00±0.24 a ]]> <![CDATA[49.09±0.19 a ]]> <![CDATA[50.57±0.23 a ]]> <![CDATA[47.69±0.22 a ]]> <![CDATA[47.51±0.22 a ]]> NEAA <![CDATA[100.87±0.22 d ]]> <![CDATA[106.13±0.22 c ]]> <![CDATA[106.97±0.22 bc ]]> <![CDATA[111.67±0.22 ab ]]> <![CDATA[111.73±0.22 ab ]]> <![CDATA[113.21±0.23 a ]]> <![CDATA[106.74±0.11 bc ]]> <![CDATA[112.09±0.23 a ]]> <![CDATA[106.35±0.22 c ]]> <![CDATA[98.95±0.22 d ]]>

[0025] The content of 17 amino acids (excluding tryptophan) in black wheat bran was determined, and the results are shown in Table 4. The most abundant amino acid in black wheat bran was glutamic acid (35.84–41.22 mg / g), and the least abundant was cysteine ​​(0–0.86 mg / g). The total amino acid content in black wheat bran ranged from 146.46 to 164.20 mg / g, the total essential amino acid content ranged from 47.51 to 51.00 mg / g, and the total non-essential amino acid content ranged from 98.95 to 113.21 mg / g. In Example 6 (1.0 MPa + 90 s), the contents of all three were the highest.

[0026] Table 5. Effects of steam explosion on the quality analysis of essential amino acids in wheat bran.

[0027] As shown in Table 5, the amino acid scores for leucine, threonine, and phenylalanine are all above 100, which is better than the WHO / FAO recommended model. Isoleucine is the first limiting amino acid. Based on the amino acid scores, the amino acid composition of wheat bran is relatively reasonable and nutritionally balanced. The biological value of well-nutritional protein foods is between 70% and 100%. Table 5 shows that the amino acid index values ​​of black wheat bran are all around 80%, and the biological value of the protein is above 70%. Both the amino acid index and biological value indicate that the protein in black wheat bran has high nutritional value.

[0028] (4) Fatty acid content analysis Figure 2 To investigate the effect of steam explosion on the fatty acid content of wheat bran, from... Figure 2 The results showed that the fatty acid value of SE black wheat bran gradually increased with prolonged storage time, but was significantly lower than that of unmodified black wheat bran. P <0.05). The comparison of fatty acid values ​​between different treatments highlights the optimal treatment. This may be because the lipase in black wheat bran is deactivated by high temperature during steam explosion, inhibiting fat oxidation in the bran and thus extending the storage period of black wheat bran. This indicates that steam explosion can effectively improve the storage performance of wheat bran.

[0029] Experimental Example 2: Analysis of Bioactive Components and Antioxidant Activity Table 6. Effects of steam explosion on the content of phytochemicals in wheat bran

[0030] Table 6 shows the changes in phytochemical content in SE black wheat bran. The content of free polyphenols gradually increased with increasing pressure and pressure-holding time. At 0.5 MPa and 1.0 MPa pressures, the contents of free anthocyanins and flavonoids gradually increased with increasing pressure-holding time, but at 1.5 MPa pressure, both contents gradually decreased with increasing time. This may be because anthocyanins and flavonoids are destroyed under high temperature and pressure, leading to a decrease in content. In Example 6 (1.0 MPa + 90 s), the contents of free polyphenols, anthocyanins, and flavonoids reached their maximum values, at 4.69 mg / g, 3.17 mg / g, and 3.53 mg / g, respectively, representing increases of 90.65%, 40.89%, and 92.90% compared to unmodified black wheat bran. Unlike free bioactive substances, the contents of bound polyphenols, anthocyanins, and flavonoids showed an overall decreasing trend after steam explosion. This indicates that steam explosion facilitates the release of some bound phenols.

[0031] (5) Changes in antioxidant properties of wheat bran The antioxidant test results of free and bound bioactive components in SE black wheat bran are as follows: Figure 3 As shown, the levels of free and bound bioactive components DPPH, ABTS, and FRAP in SE black wheat bran were significantly higher than those in the control group. Example 6 (1.0 MPa + 90 s) exhibited the highest antioxidant capacity, with a free DPPH radical scavenging rate of 61.34%, a free ABTS radical scavenging rate of 79.46%, and a free FRAP reducing capacity of 14.15 μmol / mL. Subsequent increases in treatment intensity led to a decrease or near-unchanged antioxidant capacity in the black wheat bran. The antioxidant capacity of bound DPPH, ABTS, and FRAP showed a trend of first increasing and then decreasing, or first increasing and then remaining essentially unchanged, with increasing steam explosion pressure and time. These trends indicate that excessively strong steam explosion treatment conditions are detrimental to the dissolution of phenolic acids in black wheat bran. The steam explosion treatment has a limited effect on the release of phenolic substances from the cell wall. Under different treatment conditions, insoluble substances undergo degradation, which is beneficial for the dissolution of phenolic substances to varying degrees. Once the steam explosion reaches a certain intensity, its effect becomes less pronounced and may even have adverse effects.

[0032] Experimental Example 3: Sensory Senses and Microstructure (1) Color difference value The color of black wheat bran before and after steam explosion was measured using a colorimeter. The results were obtained in terms of brightness (L), redness (a), yellowness (b), and color difference (ΔE).

[0033] Table 7. Effect of Steam Explosion on Wheat Bran Color Difference Example <![CDATA[L * ]]> <![CDATA[a * ]]> <![CDATA[b * ]]> <![CDATA[ΔE * ]]> 1 <![CDATA[65.01±0.62 c ]]> <![CDATA[5.82±0.15 f ]]> <![CDATA[18.45±0.37 c ]]> <![CDATA[31.56±0.72 g ]]> 2 <![CDATA[63.23±1.69 e ]]> <![CDATA[5.93±0.16 f ]]> <![CDATA[18.37±0.46 c ]]> <![CDATA[33.12±1.33 f ]]> 3 <![CDATA[62.63±1.86 de ]]> <![CDATA[5.94±0.15 f ]]> <![CDATA[18.57±0.37 c ]]> <![CDATA[33.74±1.52 f ]]> 4 <![CDATA[61.22±0.67 e ]]> <![CDATA[6.41±0.16 e ]]> <![CDATA[20.23±0.15 c ]]> <![CDATA[35.78±0.67 e ]]> 5 <![CDATA[58.28±1.35 f ]]> <![CDATA[6.72±0.12 d ]]> <![CDATA[20.30±4.08 c ]]> <![CDATA[38.27±0.98 d ]]> 6 <![CDATA[56.66±1.28 g ]]> <![CDATA[7.22±0.06 c ]]> <![CDATA[20.82±0.74 ab ]]> <![CDATA[40.25±0.84 c ]]> 7 <![CDATA[59.50±0.48 f ]]> <![CDATA[6.69±0.14 d ]]> <![CDATA[20.87±0.26 ab ]]> <![CDATA[37.60±0.34 d ]]> 8 <![CDATA[55.23±1.30 g ]]> <![CDATA[7.57±0.22 b ]]> <![CDATA[21.30±0.95 ab ]]> <![CDATA[41.77±0.82 b ]]> 9 <![CDATA[52.96±0.47 h ]]> <![CDATA[8.10±0.33 a ]]> <![CDATA[21.98±1.42 a ]]> <![CDATA[44.10±0.47 a ]]> 10 <![CDATA[71.00±1.59 b ]]> <![CDATA[4.54±0.55 g ]]> <![CDATA[16.22±2.38 d ]]> <![CDATA[25.24±0.55 h ]]>

[0034] Table 7 shows that the brightness value (L) of black wheat bran after the two stages of steaming and popping in the SE process... * The redness value (a) decreased significantly, while the redness value (a) decreased significantly. * ), yellowness value (b) * ) and color difference value (ΔE) * All of them increased significantly ( P <0.05). One of the main characteristics of SE (Selenium Oxide) is the drastic change in appearance color, which can be attributed to the Maillard reaction. The essence of the Maillard reaction is that the carbonyl groups in reducing sugars and other substances react with the amino groups in amino acids and proteins, leading to structural changes. Specifically, a carbonyl-amine reaction occurs inside the black wheat bran, producing large molecules of brown or black substances. At the same time, the high temperature generated during the SE process degrades substances such as cellulose and hemicellulose into sugars, which are then dehydrated into volatile substances through the caramel reaction. These condensation and polymerization occur again on the surface of the black wheat bran, forming a dark, viscous substance.

[0035] (2) Fourier transform infrared spectrum Mix 1 mg of modified wheat bran (both before and after) with 100 mg of potassium bromide, and select a scanning range of 400 cm⁻¹.-1 ~4000cm -1 The resolution is set to 4cm. -1 .

[0036] Figure 4 To illustrate the effect of steam explosion on the functional groups in wheat bran, different peaks in the infrared spectrum represent different functional groups, which are then used to qualitatively and quantitatively determine the various components in the material. Infrared spectra such as... Figure 4 As shown, at 3288 cm -1 There is a broad peak of NH bond stretching vibration at 2924 cm⁻¹. -1 ~2853 cm -1 There is a stretching vibration of a CH bond at 1700 cm. -1 ~1500cm -1 There is a stretching vibration absorption peak at 993 cm⁻¹, which may be due to the carbonyl group (C=O); -1 ~1019cm -1 The strong absorption peaks between these peaks may be due to rocking or torsional vibrations of hydrocarbons (CH). After steam explosion, the transmittance of black wheat bran increased while the peak intensity decreased, indicating that the steam vaporization (SE) affected the chemical bonds connecting dietary fibers, reducing the structural strength of the dietary fibers, making the structure looser, and degrading insoluble dietary fibers. This improved the physicochemical properties of the bran and also facilitated its grinding.

[0037] (3) Microstructure observation A small amount of wheat bran was fixed with conductive adhesive, plated with platinum, and its internal structure was observed under 5 kV conditions with a magnification of ×10000.

[0038] Figure 5 The effect of steam explosion on the internal structure of wheat bran was investigated. Example a represents Example 1 (0.5 MPa + 30 s); Example b represents Example 2 (0.5 MPa + 60 s); Example c represents Example 3 (0.5 MPa + 90 s); Example d represents Example 4 (1.0 MPa + 30 s); Example e represents Example 5 (1.0 MPa + 60 s); Example f represents Example 6 (1.0 MPa + 90 s); Example g represents Example 7 (1.5 MPa + 30 s); Example h represents Example 8 (1.5 MPa + 60 s); Example i represents Example 9 (1.5 MPa + 90 s); and Control group 10 (untreated).

[0039] SEM images showed that unmodified black wheat bran had a smooth, intact surface without any debris. SE bran, on the other hand, began to lose its luster, becoming rough and exhibiting porous or even honeycomb-like structures. The humid and hot environment, along with the forces generated during the explosion process, disrupted the morphological structure of the black wheat bran, making the pores more porous. This structural deformation helps promote the full and rapid dissolution of soluble substances and improves the hydration properties of the bran. Furthermore, experiments revealed that SE black wheat bran was easier to grind than unmodified black wheat bran, and at the same grinding time, it had a finer average particle size. This is likely due to the force degradation caused by SE on the porous structure of the black wheat bran.

[0040] Experimental Example 4: Determination of Physicochemical Properties Table 8 Effects of Steam Explosion on the Physicochemical Properties of Wheat Bran Example Water holding capacity (mg / g) Oil retention (mg / g) Swelling capacity (mL / g) 1 <![CDATA[3.09±0.08 a ]]> <![CDATA[1.68±0.13 b ]]> <![CDATA[1.87±0.12 abc ]]> 2 <![CDATA[3.08±0.09 a ]]> <![CDATA[1.61±0.14 b ]]> <![CDATA[2.07±0.23 abc ]]> 3 <![CDATA[3.12±0.11 a ]]> <![CDATA[1.57±0.14 b ]]> <![CDATA[2.13±0.12 ab ]]> 4 <![CDATA[3.07±0.13 a ]]> <![CDATA[1.59±0.22 b ]]> <![CDATA[2.13±0.23 ab ]]> 5 <![CDATA[3.09±0.15 a ]]> <![CDATA[1.51±0.17 b ]]> <![CDATA[2.13±0.23 ab ]]> 6 <![CDATA[3.16±0.12 a ]]> <![CDATA[1.50±0.14 b ]]> <![CDATA[2.20±0.20 a ]]> 7 <![CDATA[3.08±0.11 a ]]> <![CDATA[1.47±0.12 b ]]> <![CDATA[2.13±0.12 ab ]]> 8 <![CDATA[2.76±0.18 a ]]> <![CDATA[1.57±0.24 b ]]> <![CDATA[1.93±0.23 abc ]]> 9 <![CDATA[3.05±0.19 a ]]> <![CDATA[1.59±0.35 b ]]> <![CDATA[1.80±0.20 bc ]]> 10 <![CDATA[2.64±0.45 b ]]> <![CDATA[1.99±0.41 a ]]> <![CDATA[1.73±0.11 c ]]>

[0041] As a high-fiber material, wheat bran not only needs a high content of soluble dietary fiber, but also good physical properties. Good water-holding capacity is beneficial to the good hydration properties of wheat bran, thereby promoting the absorption of water by dietary fiber and increasing food viscosity. At the same time, the hydrophilicity of dietary fiber can effectively prevent intestinal diseases. As can be seen from Table 8, compared with unmodified black wheat bran, SE wheat bran has increased water-holding capacity and swelling capacity, and decreased oil-holding capacity. P <0.05%, with the highest water retention and swelling properties observed in Example 6 (1.0 MPa + 90 s). This is likely due to the breakage of the fibrous polymers in the black wheat bran under high temperature and pressure, exposing hydrophilic groups and enhancing the bran's water-binding capacity. Simultaneously, the effect of the instantaneous depressurization phase makes the bran structure more porous, absorbing and retaining a large amount of moisture. Therefore, SE treatment improves the water absorption of black wheat bran.

[0042] In summary, the method for improving the quality of black wheat bran based on steam explosion pretreatment provided by this invention specifically involves pretreating black wheat bran using steam explosion (SE) technology (1.0 MPa, 90 s). This results in a 53.63% increase in soluble dietary fiber content, and the highest levels of free phytochemicals and antioxidants. The bran color changes from light brown to dark brown / dark brown, exhibits a porous honeycomb structure, and shows increased water retention and swelling capacity. Infrared spectroscopy reveals the destruction of methyl and methylene structures, leading to a looser texture. The fatty acid value is significantly reduced, effectively extending the storage period and shelf life. This comprehensive improvement in nutritional components, physicochemical properties, biological activity, and storage characteristics demonstrates significant technical advantages.

[0043] Application examples 1. A method for preparing a low-GI whole-grain biscuit, comprising the following steps: (1) Prepare raw materials: Based on 100% low-gluten flour, the ingredients are: 50% butter, 40% shortening, 20% egg white, 17.53% improved wheat bran (as in Example 6), 5.07% resistant dextrin, 30% maltitol, and 12.15% inulin. (2) Add butter, shortening and maltitol in order, stir well and then add egg liquid. Beat with an egg beater for 3 minutes to make the butter fully mixed with air to make the biscuits crisp and ensure even emulsification. Then add the well mixed low-gluten flour, modified wheat bran, resistant dextrin and inulin, and knead by hand into a dough of medium softness. (3) Take out the dough, then press it into shape with a cookie cutter, preheat the oven to 155°C, bake for 14 minutes with both top and bottom heat, and after baking, take it out and place it on a sample tray to cool and pack it into bags.

[0044] 2. Single-factor experiment (1) Effect of improved wheat bran addition on biscuits The remaining ingredients were kept the same, and 15%, 20%, 25%, 30%, and 35% of the modified wheat bran were added respectively. Sensory evaluation and hardness and brittleness analysis were performed on the biscuits respectively.

[0045] Depend on Figure 6 It can be seen that the sensory score initially increases and then decreases with increasing bran content. The highest sensory score (84.1 points) is achieved when the bran content is 25%, while the score drops to only 61.1 points when the bran content is 35%. When the bran content is below 25%, the bran aroma is not pronounced, and the cookies have a sticky texture. Compared to cookies with 25% bran, while the increased bran content produces a more noticeable bran aroma, the dough has a cross-section, resulting in a rough, dry texture and an uneven appearance, thus leading to a lower score.

[0046] Figure 7 In this study, the hardness and crispness of biscuits showed a general trend of slow decrease followed by a significant increase as the amount of wheat bran added increased. When the amount of wheat bran added was less than 25%, it increased the softness of the biscuits, but the texture of the wheat bran was rough. When the amount added was higher than 25%, the biscuits had a grainy texture and a loose internal structure, which increased the hardness and crispness.

[0047] (2) Effect of resistant dextrin addition on biscuit quality The effects of different amounts of resistant dextrin on the sensory evaluation, hardness, and crispness of biscuits, such as Figure 8 and Figure 9 .

[0048] Figure 8In the study, the sensory score of the biscuits initially increased and then decreased with increasing resistant dextrin content, reaching its highest point of 81.6 at 6%. Resistant dextrin can improve the sensory properties of biscuits; with the addition of resistant dextrin, the biscuits maintain their shape and have a finer texture. When the dextrin content exceeds 6%, the dough becomes less soft, more difficult to shape, and the sensory evaluation declines.

[0049] like Figure 9 As shown, the changes in hardness and brittleness of biscuits caused by different amounts of resistant dextrin are basically consistent, showing a trend of decreasing and then increasing. The addition of resistant dextrin hinders gluten formation, reduces dough strength, makes the dough softer and stickier, and has better extensibility, thus resulting in lower hardness and brittleness. As the amount of resistant dextrin increases, the dough becomes more difficult to form, its elasticity decreases, and its hardness and brittleness increase, reaching the highest level at an addition amount of 8%.

[0050] (3) Effect of maltitol addition on biscuit quality The effects of different amounts of maltitol on the sensory evaluation, hardness, and crispness of biscuits, such as Figure 10 and Figure 11 .

[0051] Sensory ratings of cookies with added maltitol, for example Figure 10 The levels initially increase and then decrease. When maltitol is added in small amounts, the cookies are less sweet, the caramelization is weaker, and the baked cookies are lighter in color. As the amount of maltitol increases, the cookies become smoother in texture, have a more even appearance, and a richer aroma. When the addition exceeds 40%, the cookies' taste deteriorates, becoming overly sweet, sour, and resulting in a lower sensory score.

[0052] like Figure 11 As shown, with the continuous increase of maltitol, the hardness and crispness of the biscuits show a significant upward trend. When the amount of maltitol added increases, it absorbs moisture from the dough protein, making the biscuits harder, thus leading to an increase in the hardness and crispness of the biscuits.

[0053] (4) Effect of inulin addition on biscuit quality The effects of different amounts of inulin on the sensory evaluation, hardness, and crispness of biscuits, such as Figure 12 and Figure 13 .

[0054] like Figure 12 As shown, the sensory score of the cookies initially decreased, then rebounded, and then slowly decreased again as the amount of inulin increased. Inulin contains monosaccharides and disaccharides. When inulin is added, the Maillard and caramelization reactions that occur during the baking process can cause the color to become too dark. When inulin is added further, the cookies have a more intact appearance and a more uniform thickness, and the cookies will have a better aroma. The sensory score is highest at 85.3 points when inulin content is 12.5%.

[0055] like Figure 13 As shown, the trends in hardness and crispness of cookies with added inulin are basically the opposite of those without. Cookies with added inulin have a uniform internal structure, fine pores, and a crumbly texture, indicating that the addition of inulin reduces both the hardness and crispness of the cookies.

[0056] (5) Response surface methodology and results Four independent variables—wheat bran (A), resistant dextrin (B), maltitol (C), and inulin (D)—were selected from single-factor experiments. A four-factor, three-level response surface methodology was designed, and a multiple linear regression mathematical model was established to predict the optimal formula for low-glycemic biscuits. The response surface methodology and results analysis are shown in Table 9.

[0057] Table 9 Response Surface Experimental Design and Results Analysis serial number A B C D Sensory rating hardness brittleness 1 15 6 35 15 76 1637 1152 2 20 4 35 10 71 1335 802 3 20 4 30 12.5 74 1425 787 4 20 6 35 12.5 90 1748 1325 5 20 6 35 12.5 91 1457 1011 6 25 6 35 15 72 1798 1456 7 20 6 35 12.5 89 1648 1283 8 20 8 30 12.5 72 1714 1219 9 15 4 35 12.5 73 1632 1263 10 20 4 35 15 76 1960 1537 11 25 6 30 12.5 82 1504 1160 12 20 6 30 10 71 1509 1198 13 15 6 40 12.5 67 1656 1088 14 25 6 40 12.5 72 1702 1233 15 15 6 35 10 72 1494 887 16 20 6 40 15 69 1931 1298 17 20 6 35 12.5 87 1790 1352 18 20 4 40 12.5 72 1598 824 19 25 4 35 12.5 89 1376 1064 20 25 6 35 10 76 1325 1029 21 20 8 35 15 80 1695 1317 22 20 8 40 12.5 72 1230 908 23 15 6 30 12.5 73 1563 1219 24 20 6 35 12.5 90 1333 914 25 20 6 40 10 70 1796 1424 26 15 8 35 12.5 72 1845 1437 27 20 8 35 10 74 1896 1479 28 20 6 30 15 77 1631 1270 29 25 8 35 12.5 80 1868 1474

[0058] This experiment used Design-Expert 8.0.6 to perform regression fitting analysis on the experimental results, and the obtained regression equation is as follows: Y=89.40+3.25A-0.33B-2.25C+1.33D-2.25AB-1.00AC-2.00AD+0.50BC+0.25BD-1.75CD-6.03A 2 -5.01B 2 -10.03C 2 -8.41D 2 .

[0059] Since the model's difference effect was not significant when using hardness and brittleness as criteria for data analysis, the following results analysis used sensory scores as the standard. The regression equations, analysis of variance, and significance of the experimental results are shown in Table 10.

[0060] Table 10. Analysis of variance and significance of regression equations Source of variance sum of squares Degrees of freedom Mean Square F P Significance Model 1314.02 14 93.86 7.63 0.0003 * A 126.75 1 126.75 10.31 0.0063 * B 1.33 1 1.33 0.11 0.7468 C 60.75 1 60.75 4.94 0.0432 * D 21.33 1 21.33 1.74 0.2089 AB 20.25 1 20.25 1.65 0.2202 AC 4.00 1 4.00 0.33 0.5774 AD 16.00 1 16.00 1.3 0.2731 BC 1.00 1 1.00 0.081 0.7797 BD 0.25 1 0.25 0.020 0.8886 CD 12.25 1 12.25 1.00 0.3351 <![CDATA[A 2 ]]> 236.12 1 236.12 19.21 0.0006 * <![CDATA[B 2 ]]> 226.43 1 226.43 18.42 0.0007 <![CDATA[C 2 ]]> 652.98 1 652.98 53.114 ＜0.0001 ** <![CDATA[D 2 ]]> 458.60 1 458.60 37.30 ＜0.0001 ** residual 172.12 14 12.29 Missing item 162.92 10 16.29 7.08 0.0371 Pure error 9.20 4 2.30 Total error 1486.14 28

[0061] Note: * indicates a significant difference of P < 0.05; ** indicates a highly significant difference of P < 0.0001.

[0062] Table 10 shows that the p-values ​​of A, C, and their quadratic terms in the model are all less than 0.05, indicating significant differences. The interaction term, however, shows poor significance (F=7.63, p<0.05), indicating a significant difference. This suggests that the model fits the actual experiment well with minimal error. The table also shows that among the factors affecting cookies, their influence ranks as follows: A>C>D>B, i.e., wheat bran>maltitol>inulin>resistant dextrin. The optimized cookie formula, obtained through analysis, is: 17.53% wheat bran, 5.07% resistant dextrin, 30% maltitol, and 12.15% inulin. The sensory score of the cookies under this formula reaches 90.07. Figure 14 It can directly show the interaction between various factors and their impact on the response value.

[0063] 3. Results of nutritional composition analysis of the biscuits Table 11 Physicochemical properties of cookies Nutritional components Moisture content protein Dietary fiber Fat Sample biscuit content (%) 3.81 5.33 5.29 30.7 Blank control content (%) 2.87 5.24 1.42 32.5

[0064] The physicochemical test results are shown in Table 11 above. The moisture content of the cookies is 2.12% and the fat content is 20.21%, which meets the requirements of GB / T 20980-2021 "General Rules for Biscuit Quality" for cookies with a moisture content of ≤4.0% and a fat content of ≥16.0%.

[0065] 4. Evaluation of the glycemic index of biscuits Depend on Figure 15 It can be seen that the glycemic index of this cookie is 53.92, which is less than 55, according to in vitro digestion experiments. It is a low-glycemic food and is suitable for diabetic patients to buy and eat.

[0066] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. All equivalent changes and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for preparing a steam explosion-modified grain processing by-product, characterized in that, The steps include the following: Grain processing byproducts are taken, steam is introduced, and steam explosion is performed at a pressure of 0.8-1.2 MPa for 75-110 seconds. The product is then dried at 45-60℃ and pulverized through an 80-mesh sieve to obtain the improved grain processing byproducts.

2. The method for preparing a steam explosion-modified grain processing by-product as described in claim 1, characterized in that, The grain processing by-product is selected from any one of black wheat bran, oat bran, corn bran, and buckwheat bran.

3. The method for preparing a steam explosion-modified grain processing by-product as described in claim 1, characterized in that, The conditions for the steam explosion are a pressure of 1.0 MPa and a time of 90 s.

4. The method for preparing a steam explosion-modified grain processing by-product as described in claim 1, characterized in that, The drying conditions are 50°C.

5. The use of the improved grain processing byproduct obtained by any one of the preparation methods according to claims 1-4 in the preparation of low-GI products.

6. A low-GI whole-grain biscuit, characterized in that, It comprises the following ingredients, based on 100% of low-gluten flour: 50% butter, 40% shortening, 20% egg white, 17.53% of the modified grain processing byproduct obtained by the method described in any one of claims 1-4, 5.07% resistant dextrin, 30% maltitol, and 12.15% inulin.

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