Preparation method and application of high-fiber low-GI-value biscuits

Abstract

The invention discloses a preparation method and application of high-fiber low-GI-value biscuits, and the preparation method comprises the following steps: S1: carrying out superheated steam treatment on sea rice bran to obtain stabilized sea rice bran; s2, inoculating probiotics into the stabilized sea rice bran obtained in the step S1, and fermenting to obtain fermented sea rice bran; and S3, uniformly mixing the fermented sea rice bran obtained in the step S2 with auxiliary materials, and baking to obtain the high-fiber low-GI-value biscuits, the fermented sea rice bran accounts for 12-18% of the mass of the high-fiber low-GI-value biscuit on a dry basis, and the GI value of the biscuit is 30-48. According to the preparation method provided by the invention, the sea rice bran is treated through superheated steam processing and probiotic fermentation, and lipase, polyphenol oxidase and peroxidase of the sea rice bran are inactivated, so that the sea rice bran is stable in quality and improved in flavor, the content of total phenols capable of inhibiting amylase activity is increased, and the variety of deeply-processed sea rice products is enriched.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and particularly relates to a preparation method and application of high-fiber and low-GI biscuits. Background Art

[0002] Sea rice refers to rice that is not afraid of short-term immersion in seawater and can grow normally around seashore tidal flats, inland saline-alkali land and saltwater lakes with a salt content of more than 0.3%. Sea rice grains are red, contain natural soluble red pigments, and are rich in nutrients such as starch, dietary fiber, unsaturated fatty acids and minerals. However, sea rice has defects such as hard cortex, time-consuming cooking and rough taste, which hinders the promotion and consumption of sea rice. Therefore, the development of deep processing technology for sea rice and the research and development of sea rice snacks have become issues that need to be urgently addressed.

[0003] Biscuits are a traditional snack food with a crispy texture and good flavor, which are deeply loved by consumers. At present, most biscuit products on the market have high sugar content and low plant fiber content. They are easy to increase blood sugar after intake and are not suitable for special groups such as diabetic patients. Developing biscuits with low GI value (glycemic index) using sea rice as raw material can meet the needs of diabetics and people with insufficient dietary fiber intake. At present, there are no biscuit products using sea rice as raw material on the market. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing high-fiber, low-GI biscuits based on sea rice bran, thereby solving the problem that sea rice bran is easily rancid, which is beneficial to improving the added value of sea rice and promoting the development of the sea rice processing industry.

[0005] To this end, the present invention provides a method for preparing high-fiber, low-GI biscuits, the preparation method comprising the following steps:

[0006] S1: treating sea rice bran with superheated steam to obtain stabilized sea rice bran;

[0007] S2: inoculating probiotics into the stabilized sea rice bran obtained in step S1 for fermentation to obtain fermented sea rice bran;

[0008] S3: evenly mixing the fermented sea rice bran obtained in step S2 with auxiliary materials and baking the mixture to obtain high-fiber and low-GI biscuits;

[0009] The fermented sea rice bran accounts for 12-18% of the mass of the high-fiber, low-GI biscuits on a dry basis.

[0010] The more specific steps are as follows:

[0011] S1-1. Preparation of sea rice bran: The sea rice is ground using a rice mill to obtain rice bran rich in insoluble dietary fiber and refined sea rice. Sea rice bran is rich in dietary fiber, anthocyanins and phenolic substances, and its content is higher than that of ordinary rice bran. Dietary fiber cannot be digested and utilized by the body and does not generate heat, while anthocyanins and phenolic substances can inhibit the activity of amylase in the human body and prevent blood sugar from rising. Therefore, sea rice bran is suitable for processing into low GI foods for diabetic patients. The refined sea rice prepared by grinding has a high starch content and is prone to increase blood sugar after ingestion and digestion. It is not suitable for processing low GI foods and can be used to make ordinary rice.

[0012] S1-2. Superheated steam stabilization processing of sea rice bran: The sea rice bran prepared in step S1-1 is processed by a grinder and then passed through a 60-mesh sieve, and then treated with superheated steam. The high temperature and high pressure destroy the structure of lipoxygenase, polyphenol oxidase and peroxidase in the rice bran, inactivate the activity of the enzyme, and kill the microorganisms therein, so that the sea rice bran does not become rancid and can be stored for a long time, thereby ensuring the stable quality of industrially produced rice bran biscuit products.

[0013] S2. Deep solid-state fermentation of sea rice bran probiotics: The sea rice bran prepared in step S1-2 is placed in a closed fermentation tank, supplemented with water, and then inoculated with a composite probiotic composed of bifidobacterium and lactic acid bacteria for fermentation. Because bifidobacterium is an anaerobic bacterium, lactic acid bacteria is a facultative anaerobic bacterium. In order to achieve a good fermentation effect and control the cost, the thickness and humidity of the rice bran stacking must be controlled to maintain the anaerobic environment for probiotic fermentation. The present invention increases the thickness of the rice bran stacking and fills the void space of the rice bran powder with enough water to produce an anaerobic environment suitable for probiotics, which is an innovation of the present invention. Bifidobacterium and lactic acid bacteria use the starch, sugar and protein in the rice bran to grow and produce organic acids such as lactic acid and acetic acid, thereby improving the flavor and mouthfeel of sea rice bran. On the other hand, sea rice bran contains a large amount of polyphenols connected to macromolecules such as dietary fiber and protein. Bifidobacteria and lactic acid bacteria will produce cellulase and ferulic acid esterase during their growth, which will hydrolyze polysaccharides and cellulose and release the polyphenols connected to them. Polyphenols have the biological activity of inhibiting α-amylase and glucosidase, thereby preventing the GI value of biscuits from increasing after ingestion and digestion. However, the dietary fiber structure of sea rice bran is compact and hard in texture. Not all probiotics are suitable for fermenting sea rice bran, especially bifidobacteria are strictly anaerobic bacteria. Under factory conditions, how to create an anaerobic environment at low cost is a technical problem. Therefore, scientific research is needed to screen probiotics that are suitable for fermenting sea rice bran under solid conditions and can release bound polyphenols in rice bran. This can make the rice bran fermented by probiotics conducive to the next step of preparing biscuit products with low GI values.

[0014] S3. Preparation of sea rice bran biscuits: Weigh palm oil, egg white, edible salt, sodium bicarbonate, xylitol and other food auxiliary materials, then add fermented sea rice bran, low-gluten flour, high-gluten flour and water in sequence, stir, knead into dough, and then after the dough is rested, molded, baked, cooled and other processes, high-fiber and low-GI biscuits are obtained. The biscuit formula of the present invention uses xylitol as a sweetener to replace glucose in ordinary biscuit formulas, and on the other hand, fermented sea rice bran is added as a provider of dietary fiber, which solves the problem of low dietary fiber content in biscuit products and increased GI value of diabetic patients after ingesting digestive biscuits.

[0015] In step S1-1, the sea rice is ground by a rice mill and rice bran is collected, and the weight of the rice bran accounts for 7% to 9% of the weight of the sea rice.

[0016] In step S1-2, the temperature of the superheated steam processing is 260-320°C, and the time is 2-4 minutes. After the superheated steam treatment, the lipase activity of the sea rice bran is reduced by more than 92%, the peroxidase activity is reduced by more than 90%, and the polyphenol oxidase activity is reduced by more than 90%. The acid value of the sea rice bran is lower than 8.5 mg NaOH / g.

[0017] In step S2, the process conditions for seawater rice bran fermentation are as follows:

[0018] The thickness of the sea rice bran stack is 40-80 cm, the amount of water added is 50-70% of the weight of the stabilized sea rice bran, the bacteria used for fermentation are a composite bacteria composed of bifidobacterium bifidum, bifidobacterium longum and thermophilic streptococcus, the bacterial number mixing ratio of the three in the composite bacteria is 2:1:1, inoculation and fermentation are carried out when the number of live bacteria in the bacterial culture liquid reaches 81g CFU / mL or more, the amount of bacteria added is 2-6% of the weight of the stabilized sea rice bran, the fermentation temperature is 37-42°C, and the fermentation time is 24-36h. After fermentation, compared with unfermented rice bran, the soluble total phenol in the fermented sea rice bran is increased by 80-150%, and the soluble total flavonoids is increased by 60-120%.

[0019] In step S3, the proportion of food raw materials for preparing biscuits is as follows: 120-180 parts of palm oil, 20-80 parts of egg white, 2-4 parts of sodium bicarbonate, 30-60 parts of xylitol, 100-150 parts of fermented sea rice bran, 300-700 parts of low-gluten flour, 60-100 parts of high-refined flour and 120-300 parts of water. The mass percentage of sea rice bran in the finished biscuit (on a dry basis) is 12-18%.

[0020] The baking process conditions in step S3 are as follows: baking temperature 150-180° C., baking time 10-16 min;

[0021] The GI value of the high-fiber, low-GI biscuits prepared in step S3 is 32-48.

[0022] The present invention also provides high-fiber and low-GI biscuits prepared by the preparation method.

[0023] The invention also proposes the application of the preparation method in preparing nutritious food.

[0024] In some embodiments of the present invention, the nutritional food includes nutritional food for people with high blood sugar, diabetics and / or obese people.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects:

[0026] The present invention uses sea rice as a raw material to prepare a high-fiber, low-GI rice bran biscuit product suitable for consumption by diabetic patients and people with high blood sugar. Sea rice bran is not only rich in dietary fiber, but also contains nutrients such as polyunsaturated fatty acids and proteins, as well as bioactive ingredients such as polyphenols and anthocyanins. It is very easy to go rancid when stored at room temperature, which is not conducive to industrial deep processing and utilization. The present invention treats sea rice bran through superheated steam processing and probiotic fermentation to inactivate lipase, polyphenol oxidase and peroxidase therein, thereby stabilizing its quality, improving its flavor, and increasing the total phenol content that inhibits amylase activity, and further processing to prepare biscuit products with low GI values, enriching the variety of sea rice deep processing products and increasing added value. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0028] Figure 1 The appearance diagrams of the biscuits prepared in Example 1, Example 2 and Comparative Example 3 of the present invention are shown, wherein the amounts of sea rice bran added from left to right are 0% (Comparative Example 3), 12% (Example 1) and 18% (Example 2), respectively. DETAILED DESCRIPTION

[0029] The following will be combined with the embodiments to clearly and completely describe the concept of the present invention and the technical effects produced, so as to fully understand the purpose, characteristics and effects of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0030] Example 1

[0031] This embodiment provides a method for preparing high-fiber, low-GI biscuits, which specifically comprises the following steps:

[0032] (1) Preparation of sea rice bran: 100 kg of hulled sea rice was ground with a rice mill. When the weight of the sea rice decreased by 7%, the grinding was stopped and the bran layer was collected.

[0033] (2) Superheated steam stabilization processing of sea rice bran: 7 kg of sea rice bran collected in step (1) was ground by a grinding machine and passed through a 60-mesh screen, and then placed in a superheated steam equipment for processing at a superheated steam temperature of 260° C. for a processing time of 4 min. At this time, the acid value of the sea rice bran was 4.5 mg NaOH / g;

[0034] (3) Deep solid-state fermentation of sea rice bran probiotics: The sea rice bran treated with superheated steam in step (2) is placed in a fermentation tank, the thickness of the rice bran powder is 40 cm, the amount of water added is 50% of the weight of the sea rice bran after stabilization processing, and the composite probiotics are inoculated for fermentation. The fermentation process conditions are as follows: the bacteria used for fermentation are a composite bacteria composed of Bifidobacterium bifidum, Bifidobacterium longum and Streptococcus thermophilus, the mixed bacteria ratio of the three in the composite bacteria is 2:1:1, the inoculation amount is 2% of the weight of the sea rice bran after stabilization processing, and the inoculation fermentation is carried out when the number of live bacteria in the culture fluid of the three bacteria reaches 81g CFU / mL or more; the fermentation temperature is 37°C, and the fermentation time is 36h. After fermentation, compared with the unfermented rice bran, the soluble total phenol in the sea rice bran is increased by 110%, and the soluble total flavonoids is increased by 70%.

[0035] (4) Preparation of sea rice bran biscuits: Weigh 120 parts of palm oil, 20 parts of egg white, 2 parts of sodium bicarbonate, 30 parts of xylitol, 100 parts of fermented sea rice bran, 491 parts of low-gluten flour, 70 parts of high-gluten flour and 180 parts of water. At this time, the mass percentage of sea rice bran in the finished biscuit (on a dry basis) is about 12%. The above food ingredients are stirred and kneaded into dough, and then the dough is allowed to rest, molded, and baked at 150°C for 15 minutes. After cooling, high-fiber, low-GI biscuits are obtained. The appearance of the biscuits is as follows: Figure 1 shown.

[0036] Example 2

[0037] This embodiment provides a method for preparing high-fiber, low-GI biscuits, which specifically comprises the following steps:

[0038] (1) Preparation of sea rice bran: 100 kg of hulled sea rice was ground with a rice mill. When the weight of the sea rice decreased by 9%, the grinding was stopped and the bran layer was collected.

[0039] (2) Superheated steam stabilization processing of sea rice bran: 9 kg of sea rice bran collected in step (1) was ground by a grinding machine and passed through a 60-mesh screen, and then placed in a superheated steam equipment for processing at a superheated steam temperature of 320° C. for a processing time of 2 min. At this time, the acid value of the sea rice bran was 4.3 mg NaOH / g;

[0040] (3) Deep solid-state fermentation of sea rice bran probiotics: The sea rice bran treated with superheated steam in step (2) is placed in a fermentation tank, the thickness of the rice bran powder is 80 cm, the amount of water added is 80% of the weight of the sea rice bran after stabilization processing, and the composite probiotics are inoculated for fermentation. The fermentation process conditions are as follows: the bacteria used for fermentation are a composite bacteria composed of Bifidobacterium bifidum, Bifidobacterium longum and Streptococcus thermophilus, the mixed bacteria ratio of the three in the composite bacteria is 2:1:1, the inoculation amount is 6% of the weight of the sea rice bran after stabilization processing, and the inoculation fermentation is carried out when the number of live bacteria in the culture fluid of the three bacteria reaches 81g CFU / mL or more; the fermentation temperature is 42°C, and the fermentation time is 24h. After fermentation, compared with the unfermented rice bran, the soluble total phenol in the sea rice bran is increased by 140%, and the soluble total flavonoids is increased by 120%.

[0041] (4) Preparation of sea rice bran biscuits: Weigh 180 parts of palm oil, 50 parts of egg white, 4 parts of sodium bicarbonate, 60 parts of xylitol, 150 parts of fermented sea rice bran, 344 parts of low-gluten flour, 60 parts of high-gluten flour and 150 parts of water. At this time, the mass percentage of sea rice bran in the finished biscuit (on a dry basis) is about 18%. The above food ingredients are stirred and kneaded into dough, and then the dough is allowed to rest, molded, and baked at 180°C for 10 minutes. After cooling, high-fiber, low-GI biscuits are obtained. The appearance of the biscuits is as follows: Figure 1 shown.

[0042] Comparative Example 1

[0043] This comparative example provides a method for preparing high-fiber, low-GI biscuits. The difference between this method and Example 1 is that the method lacks step (2) of superheated steam stabilization of sea rice bran, and the other steps are consistent with Example 1.

[0044] Comparative Example 2

[0045] This comparative example provides a method for preparing high-fiber, low-GI biscuits. The difference between this method and Example 1 is that the superheated steam treatment time in step (2) is adjusted to 1 min, and the other steps are consistent with Example 1.

[0046] Comparative Example 3

[0047] This comparative example provides a method for preparing biscuits. The difference between the preparation method and Example 1 is that steps (1) to (3) are omitted, and biscuits without sea rice bran are prepared according to step (4). The other components are the same as those in step (4) of Example 1. The appearance of the biscuits is as follows: Figure 1 shown.

[0048] Comparative Example 4

[0049] This comparative example provides a method for preparing high-fiber, low-GI biscuits. The difference between this method and Example 1 is that the amount of fermented sea rice bran in step (4) is adjusted to 6% of the weight of the finished biscuits. The other steps are consistent with Example 1.

[0050] Comparative Example 5

[0051] This comparative example provides a method for preparing high-fiber, low-GI biscuits. The difference between the preparation method and Example 1 is that the preparation method lacks step (3) of deep solid-state fermentation of seawater rice bran probiotics, and the other steps are consistent with Example 1.

[0052] Comparative Example 6

[0053] This comparative example provides a method for preparing high-fiber, low-GI biscuits. The only difference between the preparation method and Example 1 is that the composite probiotics used in step (3) are replaced by a composite bacteria composed of Lactobacillus plantarum and Streptococcus thermophilus in a bacterial ratio of 2:1, and the other steps are consistent with Example 1.

[0054] Comparative Example 7

[0055] This comparative example provides a method for preparing high-fiber, low-GI biscuits. The only difference between this method and Example 1 is that the thickness of the rice bran in step (3) is adjusted to 20 cm, and the amount of water added is adjusted to 20% of the weight of the stabilized sea rice bran. The other steps are consistent with Example 1.

[0056] Test example

[0057] This test example tested the physical and chemical indicators of sea rice bran and sea rice bran biscuits prepared in Examples 1 to 2 and Comparative Examples 1 to 7, including the lipase activity, polyphenol oxidase activity, peroxidase activity of sea rice bran and the GI value of the biscuit product. The results are shown in Table 1.

[0058] Table 1 Analysis results of physical and chemical indicators of sea rice bran and its biscuit products

[0059]

[0060] From Table 1, we can see that:

[0061] 1) Compared with Example 1, the sea rice bran of Comparative Example 1 has not been subjected to superheated steam processing, and its lipase activity is about 15 times that of Example 1, its peroxidase activity is about 11 times that of Example 1, and its polyphenol oxidase activity is 12.5 times that of Example 1. Therefore, the sea rice bran of Comparative Example 1 will become rancid after 24 hours in high temperature weather of 30°C, and cannot be used for the processing and preparation of biscuits.

[0062] 2) Although the sea rice bran of Comparative Example 2 was treated with superheated steam for a short time of only 1 minute, its lipase activity was about 6 times that of Example 1, its peroxidase activity was 5.5 times that of Example 1, and its polyphenol oxidase activity was 3.8 times that of Example 1. This easily led to an increase in the acid value of the sea rice bran during storage, causing it to go rancid, and was not suitable for industrial production of biscuits.

[0063] 3) In Comparative Examples 3 and 4, no sea rice bran was added or the added amount was small when preparing biscuits, resulting in the GI value of the produced biscuits being significantly higher than that of Comparative Examples 1 and 2.

[0064] 4) In the process of comparative example 5, the sea rice bran was not fermented by lactic acid bacteria, resulting in poor flavor of the rice bran, starch and sugar in the rice bran were not utilized by microorganisms, and its GI value was higher than that of example 1.

[0065] 5) In the process prepared in Comparative Example 6, sea rice bran is fermented by a composite bacteria composed of Lactobacillus plantarum and Streptococcus thermophilus, the fermentation degree is relatively light, the increase in soluble total phenols and soluble flavonoids is lower than that in Comparative Example 1, and the GI value is higher than that in Example 1 and Example 2.

[0066] 6) In the process of comparative example 7, the thickness of sea rice bran and the amount of water added were significantly less than those in examples 1 and 2, and a good anaerobic environment could not be formed for probiotic fermentation, resulting in a GI value of the prepared biscuits being higher than that in examples 1 and 2. Biscuits with high GI values ​​are not suitable for consumption by diabetic patients and cannot achieve the purpose of the invention.

[0067] In summary, the present invention prepares sea rice bran containing high dietary fiber and phenolic substances by milling, and then uses superheated steam stabilization and probiotic fermentation to inactivate the lipoxygenase, peroxidase and polyphenol oxidase contained in the sea rice bran, and then uses the sea rice bran to prepare low GI biscuits. The scheme of the present invention is conducive to enriching the types of sea rice deep-processing products and providing a new idea for the manufacture of special foods for diabetics.

[0068] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A method for preparing high-fiber, low-GI biscuits, characterized in that: The preparation method comprises the following steps: S1: treating sea rice bran with superheated steam to obtain stabilized sea rice bran; S2: inoculating probiotics into the stabilized sea rice bran obtained in step S1 for fermentation to obtain fermented sea rice bran; S3: evenly mixing the fermented sea rice bran obtained in step S2 with auxiliary materials and baking the mixture to obtain high-fiber and low-GI biscuits; The fermented sea rice bran accounts for 12-18% of the mass of the high-fiber, low-GI biscuits on a dry basis.

2. The preparation method according to claim 1, characterized in that: The temperature of the superheated steam treatment in step S1 is 260-320°C; Preferably, the time of the superheated steam treatment in step S1 is 2 to 4 minutes.

3. The preparation method according to claim 1, characterized in that: The inoculation amount of the probiotics in step S2 is 2-6% of the weight of the stabilized sea rice bran; Preferably, the probiotics in step S2 are composite bacteria consisting of Bifidobacterium bifidum, Bifidobacterium longum and Streptococcus thermophilus, and the bacterial count ratio of Bifidobacterium bifidum, Bifidobacterium longum and Streptococcus thermophilus in the composite bacteria is 2:1:

1.

4. The preparation method according to claim 1, characterized in that: The stabilized sea rice bran in step S2 is stacked at a thickness of 40 to 80 cm during fermentation; And / or, the step S2 further comprises adding water to the stabilized sea rice bran before fermentation, wherein the amount of water added is 50-70% of the weight of the stabilized sea rice bran.

5. The preparation method according to claim 1, characterized in that: The fermentation temperature in step S2 is 37-42°C; And / or, the fermentation time in step S2 is 37-42°C.

6. The preparation method according to claim 1, characterized in that: The auxiliary materials in step S3 include palm oil, egg white, sodium bicarbonate, xylitol, low-gluten flour, high-refined flour and water; Preferably, the auxiliary materials include, by weight: 120-180 parts of palm oil, 20-80 parts of egg white, 2-4 parts of sodium bicarbonate, 30-60 parts of xylitol, 300-700 parts of low-gluten flour, 60-100 parts of high-refined flour and 120-300 parts of water.

7. The preparation method according to claim 1, characterized in that: The baking temperature in step S3 is 150-180°C; Preferably, the baking time in step S3 is 10 to 16 minutes.

8. High-fiber, low-GI biscuits prepared by the method according to any one of claims 1 to 7.

9. The high-fiber, low-GI biscuit according to claim 8, characterized in that: The GI value of the high-fiber, low-GI biscuits is 32-48.

10. Use of the preparation method according to any one of claims 1 to 7 in preparing nutritious food, characterized in that: The nutritious food includes nutritious food for people with high blood sugar, diabetics and / or obese people.

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