Puffed food raw material rich in water-soluble polysaccharides, preparation method and application thereof

Abstract

The present invention discloses a puffed food raw material rich in water-soluble polysaccharides, its preparation method and application, and belongs to the field of food technology. The processing process is as follows: lotus root and black plum are added to water, boiled for 3-5 minutes, and then beaten and sieved to obtain lotus root pulp; yeast solution is added, and the lotus root pulp is fermented at low temperature, the fermentation temperature is 15-20°C, and the fermentation time is 20-30 hours; then Poria cocos pulp is added to the fermentation product, and fermentation is carried out at room temperature, the fermentation temperature is 22-26°C, and the fermentation time is 20-30 hours; the fermentation product is centrifuged, and the solid is dried at 70-90°C; the puffing conditions are: screw speed 70-90r / min, puffing temperature 70-80°C in zone I, 100-120°C in zone II, and 130-150°C in zone III. The puffed food raw material of this patent has a high content of water-soluble polysaccharides, and has the advantages of high puffing degree, strong tooth feel, juicy feeling and special flavor.

Description

Technical Field

[0001] The present invention relates to the field of food technology, and in particular to a puffed food raw material rich in water-soluble polysaccharides, a preparation method and application thereof. Background Art

[0002] Poria cocos is the dried sclerotium of the fungus Poriacocos (Schw.) Wolf, a member of the Polyporaceae family. The Shennong Bencao Jing (Shennong's Classic of Materia Medica) lists it as a top-grade product, boasting diuretic, spleen-tonifying, and calming properties. Polysaccharides, comprising 70%-90% of its dry weight, are its primary component. Poria cocos polysaccharides are a natural immune enhancer, promoting cellular and humoral immunity, enhancing the phagocytic capacity of phagocytes, promoting antibody production, and increasing cytokine secretion by T cells. Modern pharmacological studies have demonstrated significant efficacy in multiple pharmacological activities, including tumor suppression, anti-inflammatory, and immune regulation. Solubility significantly influences the bioactivity of polysaccharides. Water solubility is paramount for their biological activity, but water-soluble polysaccharides only account for approximately 3% of the total polysaccharide content, with the remainder being water-insoluble acidic polysaccharides. The poor solubility of Poria cocos polysaccharides presents a significant challenge in their research.

[0003] Currently, chemical modifications such as carboxymethylation and sulfate esterification are used to modify the structure of Poria cocos polysaccharide to increase its solubility. However, this method has long reaction times, multiple steps, and high requirements for equipment and temperature. Furthermore, the introduction of a large number of toxic and hazardous chemicals and exogenous ions also brings inconvenience to subsequent food processing, which has significant limitations in practical applications. There are also methods that use alkaline solution extraction, followed by purification and preparation into a powder, which is then added to the corresponding base material when used, but this does not directly improve its water solubility.

[0004] This patented method combines fermentation and expansion, allowing Poria cocos to reduce its degree of polymerization in an acidic and mild environment. The resulting swollen tissue shape after fermentation is more conducive to expansion, which in turn increases the water solubility of the polysaccharide. Furthermore, the process produces unique amino acid metabolites, which impart a pleasant flavor and create a flavorful product. This method offers the advantages of low cost and high safety, and can be directly used in the food industry. Summary of the Invention

[0005] The present invention uses lotus root, black plum, and Poria cocos as raw materials, and produces a puffed food raw material through fermentation and puffing processes. The undissolved precipitates in the raw materials—lotus root and Poria cocos particles—are fermented in an acidic environment, causing some of the glycosidic bonds at the chain ends or side chains to hydrolyze and fall off. This enhances the expansion force, causing the particles to swell, resulting in a firmer texture, stronger tensile strength, and good formability. This increases the brittleness and strength of the product, enhancing the texture of the puffed product and making it more chewy and firm. Furthermore, lotus root is rich in amylopectin, which accounts for 80% of the total starch content. During puffing, amylopectin forms a network structure, which helps increase the puffed volume and enhance the crispness of the puffed product. The combination of the two creates a superior product with a high degree of expansion and a firm texture.

[0006] In one aspect, embodiments of the present invention provide a puffed food ingredient rich in water-soluble polysaccharides. The ingredient is made from lotus root, black plum (specifically, black plum flesh), and Poria cocos, and is fermented, solid-liquid separated, dried, and puffed. The mass ratio of lotus root, black plum, and Poria cocos is 1000-2000:10-20:1500-3000. The yeast dosage is 0.1-0.5‰ of the raw material weight, and the fermentation time is 36-60 hours. The ingredient is dried to a moisture content of 15-20%, and the puffing temperature is 60-150°C.

[0007] Lotus root is rich in starch, providing a rich carbon source for microorganisms. Cooking the lotus root gelatinizes the starch, which is then hydrolyzed into glucose by its own amylase, providing nutrients for yeast growth and reproduction. Lotus root also contains a high content of amylopectin, which accounts for 80% of the total starch content. This amylopectin forms a network structure during puffing, which helps increase the puffed volume and enhance the crispness of the product. This expanded structure has enhanced water and oil absorption, resulting in a richer and juicier product. Compared to more common starch ingredients like rice flour and wheat flour, lotus root offers advantages in crispness, juiciness, and flavor.

[0008] Black plums contain a large amount of organic acids, such as citric acid, malic acid, tartaric acid, and vitamin C. By adding black plums, the pH is adjusted, increasing the acidity of the fermentation feedstock. On the one hand, increasing acidity promotes starch hydrolysis, providing sufficient glucose nutrition for the yeast. On the other hand, adjusting the acidity reduces the viscosity of the lotus root liquid, allowing for a more complete and even mixing of the yeast and lotus root liquid, facilitating smooth fermentation. Black plums also contain antibacterial substances such as ellagic acid and polyphenolic compounds, such as resveratrol and rutin. These natural, mild antibacterial substances can help kill harmful microorganisms during fermentation, preventing them from interfering with the normal fermentation process and even preventing substrate deterioration, thus facilitating fermentation. Furthermore, black plums contain carbohydrates and various amino acids, which, when used in food ingredients, enhance the taste of the final product, creating a sweet and sour flavor. At the same time, the acidity is adjusted by controlling the amount of black plums, and then the degree of fermentation is controlled (this patent only requires partial fermentation). On the one hand, the fermentation product glucose can meet the nutritional needs of yeast growth. On the other hand, the unfermented part is the raw material for the later puffing, thereby improving the puffing degree and water / oil absorption performance of the puffed product.

[0009] The puffed food raw material of the present invention has the following characteristics:

[0010] 1. Rich in nutrients, such as high content of water-soluble polysaccharides, which exceeds 10%.

[0011] 2. It has a unique aroma and is an amino acid metabolite with the flavor of Poria cocos and lotus root.

[0012] 3. The expanded tissue has a distinct meaty feel when chewed.

[0013] 4. It has a sour and fragrant taste, which is acceptable to most people.

[0014] 5. After being made into food, it has a juicy feeling when chewed.

[0015] 6. When preparing spicy strips and other foods, it has good oil and water absorption and is easy to absorb seasonings.

[0016] Furthermore, the liquid obtained from the solid-liquid separation is heated and concentrated to obtain a concentrated liquid. This concentrated liquid can also be used as a food ingredient and can be used in combination with puffed food ingredients during food processing. The relative density of the concentrated liquid is 1.1-1.2. The solid obtained from the solid-liquid separation is then dried. When preparing food, the concentrated liquid and puffed food ingredients can be used together or separately.

[0017] Among them, the yeast in the embodiment of the present invention is edible round yeast. Edible round yeast has strong acid resistance. During the growth and fermentation process of yeast, the environment is acidic. Selecting acid-resistant yeast can utilize organic matter to synthesize its own protein and reproduce or produce acid-resistant metabolites in an environment with a low pH. In traditional fermentation, the optimal pH is regulated by using neutralizers such as ammonia water, NaOH solution and other neutralizers. The amount of use is difficult to grasp and the production cost is high. Selecting acid-resistant yeast is suitable for fermentation under acidic conditions. It is not necessary to add a neutralizer to neutralize the acid produced during the fermentation process, and to a certain extent, it can avoid contamination by miscellaneous bacteria, while saving costs and being suitable for industrial production. In addition, it does not use acid as a carbon source for fermentation, and does not cause a reduction in organic acid content.

[0018] Specifically, the fermentation process is as follows: lotus root and black plum are added to water, boiled for 3-5 minutes, then beaten and sieved to obtain lotus root pulp; yeast solution is added, and the lotus root pulp is fermented at low temperature at a temperature of 15-20°C for 20-30 hours. Poria cocos pulp is then added to the fermented product and fermented at room temperature at a temperature of 22-26°C for 20-30 hours. In this patent, step-by-step fermentation is used for better results.

[0019] The drying process of the present invention is as follows: the solid separated from the solid-liquid is dried at 70-90°C.

[0020] The puffing conditions of the present invention are: screw speed 70-90 r / min, puffing temperature 70-80° C. in zone I, 100-120° C. in zone II, and 130-150° C. in zone III.

[0021] Preferably, the mass ratio of lotus root, black plum and poria powder is 1500:15:2000; the amount of yeast used is 0.2-0.3‰ of the weight of the raw materials, the low-temperature fermentation time is 24 hours, and the room-temperature fermentation time is 24 hours; and the drying is carried out at 70-90°C for 10-16 hours.

[0022] On the other hand, the present invention also provides a method for preparing a puffed food raw material rich in water-soluble polysaccharides, the method comprising the following steps:

[0023] (1) Prepare the raw materials: Take 1000-2000 parts by weight of fresh peeled lotus root and dice it; take 10-20 parts by weight of black plum; mix the lotus root and black plum, add water at a material-liquid mass ratio of 1:2-3, boil for 3-5 minutes, cool, beat and sieve (specifically, sieve through a 100-mesh sieve) to obtain lotus root pulp. Take 0.5-2.0 parts by weight of yeast, add 5-8 times its weight of water (water temperature is 25-30℃), stir evenly, let it stand for 10-20 minutes to obtain yeast solution, and activate the yeast. Take 1500-3000 parts by weight of Poria cocos and crush it (specifically, crush it into fine powder, such as one that can pass through a No. 5 sieve), add water at a material-liquid mass ratio of 1:1-1.5, and mix well to obtain Poria cocos pulp.

[0024] (2) Low-temperature fermentation: Mix the yeast solution and lotus root pulp and ferment at 15-20°C for 20-30 hours.

[0025] (3) Fermentation at room temperature: Mix the Poria cocos pulp and the fermentation product obtained in step (2) and ferment at 22-26°C for 20-30 hours.

[0026] (4) Drying: The fermentation product obtained in step (3) is subjected to solid-liquid separation (specifically, centrifugation), and the solid is dried at 70-90°C to a moisture content of 15-20%.

[0027] (5) Puffing: The product of step (4) is stirred and mixed for 5-7 minutes, allowed to stand for 20-40 minutes; and then puffed at 60-150° C. to obtain a puffed food raw material rich in water-soluble polysaccharides.

[0028] Wherein, in step (5), the puffing conditions are: screw speed 70-90r / min, puffing temperature 70-80℃ in zone I, 100-120℃ in zone II, and 130-150℃ in zone III.

[0029] On the other hand, the present invention also provides the use of the aforementioned puffed food raw materials rich in water-soluble polysaccharides in the preparation of spicy strips, shachima, brown rice rolls or biscuits.

[0030] The preparation process of spicy strips is as follows: cutting the puffed food raw materials into strips, stirring and soaking the seasoning, concentrated liquid and the puffed food raw materials after cutting into strips to obtain spicy strips, and concentrating the liquid separated from the solid and liquid by heating to obtain a concentrated liquid, and the relative density of the concentrated liquid is 1.1-1.2.

[0031] Specifically, the preparation process of spicy strips using the puffed food raw materials of this patent includes the following steps:

[0032] (1) Prepare raw materials: take 1000-2000 parts by weight of fresh peeled lotus root and dice it; take 10-20 parts by weight of black plum meat; mix the lotus root and black plum meat, add water at a material-liquid mass ratio of 1:2-3, boil for 3-5 minutes, cool, beat and sieve (specifically, sieve through a 100-mesh sieve) to obtain lotus root pulp; take 0.5-2.0 parts by weight of yeast, add 5-8 times the weight of water (specifically at 25-30°C), stir evenly, let stand for 10-20 minutes to obtain yeast solution, and activate the yeast; take 1500-3000 parts by weight of Poria cocos and crush it (specifically, crush it into fine powder, such as one that can pass through a No. 5 sieve), add water at a material-liquid mass ratio of 1:1-1.5, and mix well to obtain Poria cocos pulp.

[0033] (2) Low-temperature fermentation: Mix the yeast solution and lotus root pulp and ferment at 15-20°C for 20-30 hours.

[0034] (3) Fermentation at room temperature: Mix the Poria cocos pulp and the fermentation product obtained in step (2) and ferment at 22-26°C for 20-30 hours.

[0035] (4) Drying: The fermentation product obtained in step (3) is subjected to solid-liquid separation (specifically, centrifugation), and the solid is dried at 70-90° C. to a moisture content of 15-20% to obtain a puffed raw material; the liquid is heated and concentrated to a relative density of 1.1-1.2 to obtain a concentrated liquid.

[0036] (5) Puffing: Stir and mix the puffing raw materials for 5-7 minutes, let them stand for 20-40 minutes, and then puff to obtain puffed food raw materials. The puffing conditions are: screw speed 70-90 r / min, puffing temperature 70-80°C in zone I, 100-120°C in zone II, and 130-150°C in zone III.

[0037] (6) Cutting into strips: Cut the puffed food raw materials into strips 10-15 cm long.

[0038] (7) Preparation of spicy strips: stir the seasoning, the concentrated solution obtained in step (4) and the strip-shaped puffed food raw material obtained in step (6), stir for 5-7 minutes, soak for 1-3 hours, take out and package to obtain spicy strips.

[0039] The preparation method of this patent has the following advantages:

[0040] 1. Use staged fermentation

[0041] The first stage is primarily for growth and reproduction, while the second stage is primarily for product metabolism. The first stage is conducted at a relatively suitable pH and a relatively low temperature of 15-20°C, primarily for yeast growth and proliferation, aiming to produce as much yeast as possible. The second stage, with the temperature raised to 22-26°C, primarily promotes yeast metabolism, increasing metabolic acid production. The continuously formed suitable acidic environment and abundant glucose further promote the release of acidic metabolites, ultimately forming an acidic environment for Poria fermentation.

[0042] 2. Microbial mild fermentation promotes the degradation of Poria cocos, produces small particles of water-soluble polysaccharides, and forms special flavor substances

[0043] The fermentation environment is acidic, and the metabolites produced by fermentation contain a large amount of organic acid. When Poria cocos is in an acidic environment for a long time, its internal degree of polymerization will decrease. Because acid is a good proton donor, it can promote the hydrolysis and detachment of some glycosidic bonds, especially those at the chain ends or branches, to produce new reducing ends. The molecular degree of polymerization also decreases, and it is converted into soluble polysaccharides. At the same time, the fermentation environment temperature is not too high, and the main chain repeating structure of the sugar chain is relatively stable, without destroying the active three-dimensional structure of the polysaccharide. After fermentation, the swelling power and solubility of the polysaccharide are higher. The enzymes produced during the fermentation process partially degrade the original high-polymerization polysaccharide clumps into small, loosely structured, water-soluble polysaccharides, thereby increasing the area in contact with water and improving swelling power and solubility.

[0044] During the fermentation process, some proteins in Poria cocos and lotus root are selectively enzymatically hydrolyzed, producing amino acid metabolites with special flavor, which bring good flavor and blend with the sour taste of the fermentation liquid to enrich the taste of the product.

[0045] 3. According to the special raw materials, the puffing process was adjusted and water-soluble polysaccharides were added.

[0046] The extrusion process utilizes a three-zone heating process, which continuously and periodically heats the material for full expansion. This not only improves the hard, compact, and inconvenient texture of Poria cocos, but also renders it fluffy and porous, creating a spongy texture that enhances its palatability. Furthermore, high-molecular-weight substances such as polysaccharides in the raw material degrade under high temperature and pressure, changing their molecular structure and increasing their water solubility. Extrusion technology offers the advantages of sustainable production, short production times, and high efficiency, making it particularly suitable for promotion in the food industry.

[0047] Extrusion puffing utilizes the principles of phase change and the thermal pressure effect of gases, using extrusion technology as a aging process to significantly increase the volume of the material after aging. It is a high-tech technology that integrates mixing, stirring, crushing, heating, cooking, sterilization, puffing, and forming. The basic principle is that the material is squeezed forward by the driving force of the extruder screw, subjecting it to mixing, stirring, friction, and high shear forces. Simultaneously, the temperature and pressure within the extruder cavity rise, causing the liquid within the material to rapidly heat up, vaporize, increase pressure, and expand. The expansion force of the gas drives the structural denaturation of the polymer components, resulting in a porous material with a network structure and a fixed shape.

[0048] The entire puffing process is divided into three stages:

[0049] The first is the phase change stage, during which the liquid within the material vaporizes due to heat absorption or overheating. As the material is propelled and stirred by the rotating screw, its temperature continues to rise. Within a certain screw speed range, the higher the speed, the greater the mechanical energy and extrusion pressure applied to the material, and the faster the temperature rises. When this value exceeds a critical value, the material's residence time in the extruder shortens, resulting in a shorter period of mechanical energy exposure and uneven heating, which can easily lead to unstable extrusion temperatures. Simultaneously, the temperature supply in Zone I stabilizes the uniform heating of the material. Therefore, an appropriate screw speed and Zone I temperature range are conducive to uniform mixing, heating, and vaporization of the material.

[0050] The second stage is the pressurization phase, where the vaporized gas rapidly increases in pressure and begins to expand the material. As the gap between the screw and the sleeve narrows, the material continues to break up into clumps and generate backflow. The greater the backflow, the greater the pressure, reaching approximately 1500 kPa. Simultaneously, as the temperature in Zones II and III rises, the material absorbs more heat, accelerating the rate of water evaporation and increasing the intensity of the vaporization. After vaporization, the material's crystal structure is destroyed, resulting in a textured texture. The high temperature and high pressure initially destroy the polymer structure.

[0051] The third stage is the curing phase. When the instantaneous pressure inside the material reaches or exceeds the limit, gas rapidly escapes, and the interior dries out due to water loss, ultimately forming an expanded product. At this point, the material is discharged from the mold hole to normal atmospheric pressure. The water in the material evaporates instantly, expands, and cools, causing the polymer substances in the material to expand, forming countless fine, porous sponges.

[0052] 4. Moisture Control Before Puffing

[0053] The expansion dynamics are primarily generated by the energy released by water within the material and are closely related to the moisture content of the expanded raw material. Under the same external energy supply, water, due to its small molecular weight, low boiling point, and easy vaporization and expansion, is the first component within the material to experience increased thermal motion. When the energy gained by water molecules exceeds the limit of their mutual binding, they disperse, causing a change in the moisture state within the material, resulting in a phase transition and steam expansion. This inevitably impacts the structure of the materials in contact with them. When this impact force exceeds the forces maintaining the spatial structure of the macromolecular material and also exceeds the support force maintained by the macromolecular material, it causes expansion and deformation of the spatial structure of these macromolecular materials, ultimately leading to changes in the texture of the expanded material. Theoretically, a higher water content generates more steam, increases the expansion dynamics, and significantly impacts the expansion effect. However, excessive moisture content will affect the normal expansion. When excess water is supplied with energy externally, it is easy to vaporize first due to the weak binding force between it and other components of the material, occupying effective energy and affecting the expansion effect. Moreover, excess water is often free water or surface-adsorbed water, which is difficult to replace or occupy the original spatial position of bound and colloidal water molecules. This part of interstitial water is often not in a closed gas chamber and is unlikely to become the driving force for expansion. Even if the material containing excess water undergoes the expansion process, its finished product will become soft due to the high moisture content of the finished product, losing the unique flavor of the expanded product. DETAILED DESCRIPTION

[0054] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention are described in further detail below.

[0055] Example 1

[0056] Example 1 provides a method for preparing spicy strips, comprising the following steps:

[0057] (1) Preparation of slurry: Take 1.5 kg of fresh peeled lotus root, dice it, and take 15 g of black plum meat. Add water at a material-liquid ratio of 1:2, boil for 3 minutes, cool it slightly, beat it repeatedly, and pass it through a 100-mesh sieve. Take 0.8 g of highly active edible round yeast (Candida utilis) dry yeast, add 5 times its weight of water at 25°C, stir it evenly, and let it stand for 15 minutes. Add the yeast solution to the lotus root slurry, stir it evenly, and keep it at 15°C for 24 hours to prepare the slurry. Stir it every 30 minutes to make it uniform.

[0058] (2) Take 2 kg of dry Poria cocos cubes, crush them into fine powder, add water at a material-liquid ratio of 1:1, stir and mix, add to the slurry obtained in step (1), and keep warm at 22°C for 24 hours, stirring every 30 minutes during the process to ensure uniformity.

[0059] (3) The fermentation product obtained in step (2) was centrifuged, and the supernatant was boiled and concentrated for 1 hour to a relative density of 1.1 to obtain a fermentation broth concentrate. The lower precipitate was dried at 80°C for 14 hours to a water content of 16%, and formed into a ball when squeezed lightly, thereby obtaining a puffed raw material.

[0060] (4) Place the puffed raw materials into a blender and mix thoroughly for 5 minutes. Let it rest for 30 minutes. The mixed puffed raw materials are then fed into an extruder and extruded at high temperature. The screw speed is 80 rpm, and the puffing temperature is 80°C in Zone I, 100°C in Zone II, and 130°C in Zone III. The mixture is then cut into 10 cm strips.

[0061] (5) Put the spicy strips into a mixer, add the fermentation liquid concentrate, stir for 5 minutes, soak for 2 hours, take out and package. In this embodiment, in order to facilitate the determination of water-soluble polysaccharides, no seasoning was added.

[0062] Example 2

[0063] Example 2 provides a method for preparing spicy strips, comprising the following steps:

[0064] (1) Preparation of slurry: Take 1.5 kg of fresh peeled lotus root, dice it, and take 15 g of black plum meat. Add water at a material-liquid ratio of 1:2.5, boil for 4 minutes, cool it slightly, beat it repeatedly, and pass it through a 100-mesh sieve. Take 1 g of highly active edible round yeast (Candida utilis) dry yeast, add 6 times its weight of water at 28°C, stir it evenly, and let it stand for 15 minutes. Add the yeast solution to the lotus root slurry, stir it evenly, and keep it at 20°C for 24 hours to prepare the slurry. Stir it every 30 minutes to make it uniform.

[0065] (2) Take 2 kg of dry Poria cocos cubes, crush them into fine powder, add water at a material-liquid ratio of 1:1.5, stir and mix, add to the slurry obtained in step (1), and keep warm at 24°C for 24 hours, stirring every 30 minutes during the process to make it uniform.

[0066] (3) The fermentation product obtained in step (2) was centrifuged, and the supernatant was boiled and concentrated for 2 hours to a relative density of 1.2 to obtain a fermentation broth concentrate. The lower precipitate was dried at 80°C for 12 hours to a water content of 18%, and formed into a ball when squeezed lightly, thereby obtaining a puffed raw material.

[0067] (4) Place the puffed raw materials into a blender and mix thoroughly for 7 minutes. Let it rest for 30 minutes. The mixed puffed raw materials are then fed into an extruder and extruded at high temperature. The screw speed is 75 rpm, and the puffing temperatures are 70°C for Zone I, 110°C for Zone II, and 140°C for Zone III. The mixture is then cut into 15 cm strips.

[0068] (5) Put the strips from step (4) into a mixer, add the fermentation liquid concentrate, stir for 6 minutes, soak for 2 hours, take out and package. In this example, in order to facilitate the determination of water-soluble polysaccharides, no seasoning was added.

[0069] Example 3

[0070] Example 3 provides a method for preparing spicy strips, comprising the following steps:

[0071] (1) Preparation of slurry: Take 1.5 kg of fresh peeled lotus root, dice it, and take 15 g of black plum meat. Add water at a material-liquid ratio of 1:2.5, boil for 5 minutes, cool it slightly, beat it repeatedly, and pass it through a 100-mesh sieve. Take 0.9 g of highly active edible round yeast (Candida utilis) dry yeast, add 8 times its weight of 30°C water, stir it evenly, and let it stand for 15 minutes. Add the yeast solution to the lotus root slurry, stir it evenly, and keep it at 18°C ​​for 24 hours to prepare the slurry. Stir it every 30 minutes to make it uniform.

[0072] (2) Take 2 kg of dry Poria cocos cubes, crush them into fine powder, add water at a material-liquid ratio of 1:1.2, stir and mix, add to the slurry obtained in step (1), and keep warm at 26°C for 24 hours, stirring every 30 minutes during the process to make it uniform.

[0073] (3) The fermentation product obtained in step (2) was centrifuged, and the supernatant was boiled and concentrated for 1.5 hours to a relative density of 1.2 to obtain a fermentation broth concentrate. The lower precipitate was dried at 80°C for 16 hours to a water content of 15%, and formed into a ball when squeezed lightly, thereby obtaining a puffed raw material.

[0074] (4) Place the puffed raw materials into a blender and mix thoroughly for 6 minutes. Let it rest for 30 minutes. The mixed puffed raw materials are then fed into an extruder and extruded at high temperature. The screw speed is 90 r / min, and the puffing temperatures are 70°C in Zone I, 100°C in Zone II, and 150°C in Zone III. The mixture is then cut into 12 cm strips.

[0075] (5) Put the strips from step (4) into a mixer, add seasoning and fermentation liquid concentrate, stir for 6 minutes, soak for 2 hours, and take out and package.

[0076] Control Example 1: Unfermented and unexpanded

[0077] Comparative Example 1 provides a method for preparing a mixed powder, comprising the following steps:

[0078] (1) Take 1.5 kg of fresh peeled lotus root, dice it, add water at a material-liquid ratio of 1:2, boil it for 3 minutes, cool it slightly, beat it repeatedly, and pass it through a 100-mesh sieve. Spray dry the juice into powder.

[0079] (2) Take 2 kg of dried Poria cocos and grind it into fine powder.

[0080] (3) Mix lotus root powder and poria powder.

[0081] Control Example 2: Direct expansion without fermentation

[0082] Comparative Example 2 provides a method for preparing a puffed raw material, comprising the following steps:

[0083] (1) Take 1.5 kg of fresh peeled lotus root, dice it, add water at a material-liquid ratio of 1:2, boil it for 3 minutes, cool it slightly, beat it repeatedly, and pass it through a 100-mesh sieve. Spray dry the juice into powder.

[0084] (2) Take 2 kg of dried Poria cocos and grind it into fine powder.

[0085] (3) Mix the lotus root powder and poria powder, add appropriate amount of water during the process, make them into a ball when held in the hand, and they will fall apart when squeezed lightly to obtain the puffed raw material.

[0086] (4) Put the puffed raw materials into the blender, mix well for 5 minutes, and let it stand for 30 minutes.

[0087] (5) Feed the mixed puffed raw materials into an extruder and extrude them at high temperature. The screw speed is 80 r / min, and the puffing temperature is 80°C in zone I, 100°C in zone II, and 130°C in zone III. Cut the mixture into 10 cm strips.

[0088] Control Example 3: Fermentation without expansion

[0089] Comparative Example 3 provides a method for preparing a food raw material that has not been puffed, comprising the following steps:

[0090] (1) Preparation of slurry: Take 1.5 kg of fresh peeled lotus root, dice it, and take 15 g of black plum meat. Add water at a material-liquid ratio of 1:2, boil for 3 minutes, cool it slightly, beat it repeatedly, and pass it through a 100-mesh sieve. Take 0.8 g of highly active edible round yeast (Candida utilis) dry yeast, add 5 times its weight of water at 25°C, stir it evenly, and let it stand for 15 minutes. Add the yeast solution to the lotus root slurry, stir it evenly, and keep it at 15°C for 24 hours to prepare the slurry. Stir it every 30 minutes to make it uniform.

[0091] (2) Take 2 kg of dry Poria cocos cubes, grind them into fine powder, add water at a material-liquid ratio of 1:1, stir and mix, add to the slurry obtained in step (1), and keep warm at 22°C for 24 hours, stirring every 30 minutes during the process to make it uniform.

[0092] (3) Spray-drying the fermentation liquid into powder.

[0093] Comparative Example 4 No black plums provided

[0094] Reference Example 4 provides a method for preparing a food raw material, comprising the following steps:

[0095] (1) Preparation of slurry: Take 1.5 kg of fresh peeled lotus root, cut into cubes, add water at a material-liquid ratio of 1:2, boil for 3 minutes, cool slightly, beat repeatedly, and pass through a 100-mesh sieve. Take 0.8 g of highly active edible round yeast (Candida utilis) dry yeast, add 5 times the amount of 25°C water, stir evenly, and let it stand for 15 minutes. Add the yeast solution to the lotus root slurry, take 120 ml of acetic acid, dilute it with water to 500 ml, add it to the lotus root slurry, stir evenly, and keep it at 15°C for 24 hours to prepare the slurry. Stir every 30 minutes to make it uniform.

[0096] (2) Take 2 kg of dry Poria cocos cubes, grind them into fine powder, add water at a material-liquid ratio of 1:1, stir and mix, add to the slurry obtained in step (1), and keep warm at 22°C for 24 hours, stirring every 30 minutes during the process to make it uniform.

[0097] (3) Spray-drying the fermentation liquid into powder.

[0098] Control Example 5 Direct Fermentation

[0099] Reference Example 5 provides a method for preparing a food raw material, comprising the following steps:

[0100] (1) Preparation of slurry: Take 1.5 kg of fresh peeled lotus root, dice it, and take 15 g of black plum meat, add water at a material-liquid ratio of 1:2, boil for 3 minutes, cool it slightly, beat it repeatedly, and pass it through a 100-mesh sieve.

[0101] (2) Take 2kg of dry Poria cocos, grind it into fine powder, add water at a material-liquid ratio of 1:1, and stir to mix.

[0102] (3) Take 0.8 g of highly active edible round yeast (Candida utilis) dry yeast, add 5 times its weight of 25°C water, stir well, and let it stand for 15 minutes.

[0103] (4) Add the yeast solution to the lotus root pulp and stir evenly. Then add the Poria solution and stir evenly. Keep warm at 22°C for 48 hours to prepare the pulp. Stir every 30 minutes to make it uniform.

[0104] (5) Spray-dry the fermentation liquid into powder.

[0105] Water-soluble polysaccharide comparison experiment:

[0106] Take 0.5g of each sample of Example 1-2 and Reference Example 1-5, add 150ml of 80% ethanol, heat under reflux in a water bath for 1 hour, filter while hot, wash the residue with 80% hot ethanol 3 times, 10ml each time, put the residue and filter paper in a flask, add 150ml of water, heat under reflux in a boiling water bath for 1 hour, filter while hot, wash the residue and flask with hot water 4 times, 10ml each time, combine the filtrate and washing liquid, let cool, transfer to a 250ml measuring flask, add water to the scale, shake well, and standby. Referring to the anthrone-sulfuric acid method under the item of determination of the content of polygonatum polysaccharide in the 2020 edition of the Chinese Pharmacopoeia, the water-soluble polysaccharide content is shown in Table 1:

[0107] Table 1

[0108]

[0109] As can be seen in Table 1, Examples 1-2 exhibit superior water-soluble content compared to Control Examples 1-5. Control Example 2 was not fermented under a mild environment, and the highly polymerized polysaccharide clumps failed to degrade into loosely structured water-soluble polysaccharides, resulting in a lower water-soluble content than in the Examples. Control Example 3 was not puffed, and the polysaccharides failed to degrade under high temperature and high pressure, failing to increase the number of water-soluble polysaccharide molecules, resulting in a lower water-soluble content than in the Examples. Control Example 4 was not fermented under the mild acidic environment provided by black plum juice. On the one hand, without the black plum juice to increase the acidity of the lotus root juice, it failed to promote starch hydrolysis and provide sufficient glucose nutrients for yeast fermentation. On the other hand, without a pH suitable for yeast proliferation, fermentation was inadequate and the high molecular weight of the polysaccharide polymer structure could not be fully degraded, hindering the degradation of the water-soluble polysaccharide. Furthermore, compared to Control Example 4, the absence of black plums significantly reduced the polysaccharide content in Control Example 3. Control Example 5 was fermented directly at 22°C, failing to achieve yeast growth and proliferation at a lower temperature, thus failing to provide sufficient yeast to produce acid and ferment the polysaccharide clumps, ultimately reducing the dissolution of water-soluble polysaccharides.

[0110] Comparative Example 6: Low expansion temperature

[0111] Comparative Example 6 provides a method for preparing spicy strips, comprising the following steps:

[0112] (1) Slurry preparation: Take 1.5 kg of fresh peeled lotus root, dice it, and take 15 g of black plum meat. Add water at a material-liquid ratio of 1:2.5, boil for 5 minutes, cool it slightly, beat it repeatedly, and pass it through a 100-mesh sieve. Take 0.9 g of highly active edible round yeast (Candida utilis) dry yeast, add 8 times its weight of 30°C water, stir it evenly, and let it stand for 15 minutes. Add the yeast solution to the lotus root pulp, stir it evenly, and keep it at 18°C ​​for 24 hours to prepare the slurry. Stir it every 30 minutes to make it uniform.

[0113] (2) Take 2 kg of dry Poria cocos cubes, crush them into fine powder, add water at a material-liquid ratio of 1:1.2, stir and mix, add to the slurry obtained in step (1), and keep warm at 26°C for 24 hours, stirring every 30 minutes during the process to make it uniform.

[0114] (3) The fermentation product obtained in step (2) was centrifuged, and the supernatant was boiled and concentrated for 1.5 hours to a relative density of 1.2 to obtain a fermentation broth concentrate. The lower precipitate was dried at 80°C for 16 hours to a water content of 15%, and formed into a ball when squeezed lightly, thereby obtaining a puffed raw material.

[0115] (4) Place the puffed raw materials into a blender and mix thoroughly for 6 minutes. Let it rest for 30 minutes. The mixed puffed raw materials are then fed into an extruder and extruded at high temperature. The screw speed is 90 r / min, and the puffing temperatures are 60°C in Zone I, 90°C in Zone II, and 110°C in Zone III. Cut into 12 cm strips.

[0116] (5) Put the spicy strips into a mixing machine, add seasonings and fermentation liquid concentrate, stir for 6 minutes, soak for 2 hours, and take out the packaging.

[0117] Comparative Example 7: High expansion temperature

[0118] Comparative Example 7 provides a method for preparing spicy strips, comprising the following steps:

[0119] (1) Slurry preparation: Take 1.5 kg of fresh peeled lotus root, dice it, and take 15 g of black plum meat. Add water at a material-liquid ratio of 1:2.5, boil for 5 minutes, cool it slightly, beat it repeatedly, and pass it through a 100-mesh sieve. Take 0.9 g of highly active edible round yeast (Candida utilis) dry yeast, add 8 times its weight of 30°C water, stir it evenly, and let it stand for 15 minutes. Add the yeast solution to the lotus root pulp, stir it evenly, and keep it at 18°C ​​for 24 hours to prepare the slurry. Stir it every 30 minutes to make it uniform.

[0120] (2) Take 2 kg of dry Poria cocos cubes, crush them into fine powder, add water at a material-liquid ratio of 1:1.2, stir and mix, add to the slurry obtained in step (1), and keep warm at 26°C for 24 hours, stirring every 30 minutes during the process to make it uniform.

[0121] (3) The fermentation product obtained in step (2) was centrifuged, and the supernatant was boiled and concentrated for 1.5 hours to a relative density of 1.2 to obtain a fermentation broth concentrate. The lower precipitate was dried at 80°C for 16 hours to a water content of 15%, and formed into a ball when squeezed lightly, thereby obtaining a puffed raw material.

[0122] (4) Place the puffed raw materials into a blender and mix thoroughly for 6 minutes. Let it rest for 30 minutes. The mixed puffed raw materials are then fed into an extruder and extruded at high temperature. The screw speed is 90 r / min, and the puffing temperatures are 85°C in Zone I, 130°C in Zone II, and 160°C in Zone III. Cut into 12 cm strips.

[0123] (5) Put the spicy strips into a mixing machine, add seasonings and fermentation liquid concentrate, stir for 6 minutes, soak for 2 hours, and take out the packaging.

[0124] Comparative Example 8 Low Water Content

[0125] Comparative Example 8 provides a method for preparing spicy strips, comprising the following steps:

[0126] (1) Slurry preparation: Take 1.5 kg of fresh peeled lotus root, dice it, and take 15 g of black plum meat. Add water at a material-liquid ratio of 1:2.5, boil for 5 minutes, cool it slightly, beat it repeatedly, and pass it through a 100-mesh sieve. Take 0.9 g of highly active edible round yeast (Candida utilis) dry yeast, add 8 times its weight of 30°C water, stir it evenly, and let it stand for 15 minutes. Add the yeast solution to the lotus root pulp, stir it evenly, and keep it at 18°C ​​for 24 hours to prepare the slurry. Stir it every 30 minutes to make it uniform.

[0127] (2) Take 2 kg of dry Poria cocos cubes, crush them into fine powder, add water at a material-liquid ratio of 1:1.2, stir and mix, add to the slurry obtained in step (1), and keep warm at 26°C for 24 hours, stirring every 30 minutes during the process to make it uniform.

[0128] (3) The fermentation product obtained in step (2) was centrifuged, and the supernatant was boiled and concentrated for 1.5 hours to a relative density of 1.2 to obtain a fermentation broth concentrate. The lower precipitate was dried at 80°C for 16 hours to a water content of 13%, thereby obtaining a puffed raw material.

[0129] (4) Place the puffed raw materials into a blender and mix thoroughly for 6 minutes. Let it rest for 30 minutes. The mixed puffed raw materials are then fed into an extruder and extruded at high temperature. The screw speed is 90 r / min, and the puffing temperatures are 70°C in Zone I, 100°C in Zone II, and 150°C in Zone III. Cut into 12 cm strips.

[0130] (5) Put the spicy strips into a mixing machine, add seasonings and fermentation liquid concentrate, stir for 6 minutes, soak for 2 hours, and take out the packaging.

[0131] Comparative Example 9 has high water content

[0132] Comparative Example 9 provides a method for preparing spicy strips, comprising the following steps:

[0133] (1) Slurry preparation: Take 1.5 kg of fresh peeled lotus root, dice it, and take 15 g of black plum meat. Add water at a material-liquid ratio of 1:2-3, boil for 3-5 minutes, cool it slightly, beat it repeatedly, and pass it through a 100-mesh sieve. Take 0.8-1 g of highly active edible round yeast (Candida utilis) dry yeast, add 5-8 times its weight of water at 25-30°C, stir it evenly, and let it stand for 15 minutes. Add the yeast solution to the lotus root pulp, stir it evenly, and keep it at 15-20°C for 24 hours to prepare the slurry. Stir it every 30 minutes to make it uniform.

[0134] (2) Take 2 kg of dry Poria cocos cubes, grind them into fine powder, add water at a material-liquid ratio of 1:1-1.5, stir and mix, add to the slurry obtained in step (1), and keep warm at 22-26°C for 24 hours, stirring every 30 minutes during the process to make it uniform.

[0135] (3) The fermentation product obtained in step (2) was centrifuged, and the supernatant was boiled and concentrated for 1.5 hours to a relative density of 1.2 to obtain a fermentation broth concentrate. The lower precipitate was dried at 80°C for 16 hours to a water content of 22% to obtain a puffed raw material.

[0136] (4) Place the puffed raw materials into a blender and mix thoroughly for 6 minutes. Let it rest for 30 minutes. The mixed puffed raw materials are then fed into an extruder and extruded at high temperature. The screw speed is 90 r / min, and the puffing temperatures are 70°C in Zone I, 100°C in Zone II, and 150°C in Zone III. Cut into 12 cm strips.

[0137] (5) Put the spicy strips into a mixing machine, add seasonings and fermentation liquid concentrate, stir for 6 minutes, soak for 2 hours, and take out the packaging.

[0138] Comparative experiment on expansion, oil absorption and taste:

[0139] The spicy strips of Examples 2-3 and Comparative Examples 6-9 were taken and the expansion degree, oil absorption rate and taste evaluation were measured respectively. The results are shown in Table 2.

[0140] Expansion Determination: Cross-sectional expansion is used to indicate the product's puffing effect. Measure the diameter of the product after exposure to air for less than 20 seconds. Randomly measure 10 times per group, discarding the maximum and minimum values ​​and taking the average. Compare the calculated product cross-sectional area with the membrane pore outlet area to determine the product expansion.

[0141] Determination of oil absorption rate: Weigh 2g of sample, cut into 3 sections, place in a centrifuge tube filled with 30ml rapeseed oil, vortex for 1min (the oil must cover the embryo), leave at room temperature for 30min, take out, absorb the surface oil with filter paper and weigh it, calculate the weight of the absorbed oil, and then compare it with the sample weight to get the oil absorption rate.

[0142] Table 2

[0143]

[0144] As shown in Table 2, both the extrusion temperature and the moisture content of the material affect the product's overrun, oil absorption, and mouthfeel. When the extrusion temperature is too low, the moisture in the material is not fully evaporated, failing to form a loose, porous sponge structure. This results in inadequate expansion, low overrun, poor oil absorption, a hard, chewy texture, and difficulty in absorbing flavors. When the extrusion temperature is too high, the temperature and pressure within the barrel are excessive, causing the material to burn before it even begins to expand, leading to barrel blockage. When the moisture content is too low, the extruded material is not easily molten within the barrel, resulting in inconsistent extrusion of the spicy strips and a dry, powdery appearance. This can sometimes cause blockages and poor expansion. When the moisture content is too high, the moisture in the material acts as a plasticizer, reducing viscosity, diminishing friction between the material and the barrel, shortening the time spent in the barrel, reducing pressure at the die orifice, and resulting in a hard texture. Oil absorption is also reduced, preventing flavors from penetrating the interior and confining them to the surface.

[0145] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A puffed food raw material rich in water-soluble polysaccharides, characterized in that: Lotus root, black plum and poria cocos are used as raw materials and are obtained through fermentation, solid-liquid separation, drying and puffing. The mass ratio of lotus root, black plum and poria cocos is 1000-2000:10-20:1500-3000. The amount of yeast used is 0.1-0.5‰ of the weight of the raw materials. The fermentation process is as follows: lotus root and black plum are added into water, boiled for 3-5 minutes, and then pulped and sieved to obtain lotus root pulp; yeast solution is added and the lotus root pulp is fermented at low temperature at a fermentation temperature of 15-20°C and a fermentation time of 20-30 hours; poria cocos pulp is then added into the fermentation product and fermented at room temperature at a fermentation temperature of 22-26°C and a fermentation time of 20-30 hours; the product is dried to a moisture content of 15-20%. The puffing conditions are as follows: a screw speed of 70-90 r / min, and puffing temperatures of 70-80°C in zone I, 100-120°C in zone II, and 130-150°C in zone III.

2. The puffed food material rich in water-soluble polysaccharides according to claim 1, characterized in that: The liquid obtained by solid-liquid separation is concentrated by heating to obtain a concentrated liquid, wherein the relative density of the concentrated liquid is 1.1-1.2; and the solid obtained by solid-liquid separation is dried.

3. The puffed food material rich in water-soluble polysaccharides according to claim 1, characterized in that: The yeast is edible toruloides yeast.

4. The puffed food material rich in water-soluble polysaccharides according to claim 1, characterized in that The drying process is as follows: the solid separated from the solid-liquid is dried at 70-90°C.

5. The puffed food material rich in water-soluble polysaccharides according to claim 4, characterized in that: The mass ratio of the lotus root, black plum and poria is 1500:15:2000; the amount of the yeast is 0.2-0.3‰ of the weight of the raw materials; the low-temperature fermentation time is 24 hours, and the room-temperature fermentation time is 24 hours; and the drying is carried out at 70-90°C for 10-16 hours.

6. A method for preparing a puffed food raw material rich in water-soluble polysaccharides, characterized in that: The method comprises the following steps: (1) Prepare raw materials: take 1000-2000 parts by weight of fresh peeled lotus root and dice it; take 10-20 parts by weight of black plum; mix the lotus root and black plum, add water at a material-liquid mass ratio of 1:2-3, boil for 3-5 minutes, cool, beat and sieve to obtain lotus root pulp; take 0.5-2.0 parts by weight of yeast, add 5-8 times the weight of water, stir evenly, and let stand for 10-20 minutes to obtain yeast solution; take 1500-3000 parts by weight of Poria cocos and crush it, add water at a material-liquid mass ratio of 1:1-1.5, and mix evenly to obtain Poria cocos pulp; (2) Low-temperature fermentation: Mix the yeast solution and lotus root pulp and ferment at 15-20°C for 20-30 hours; (3) Fermentation at room temperature: Mix the Poria cocos pulp and the fermentation product obtained in step (2), and ferment at 22-26° C. for 20-30 h; (4) Drying: The fermentation product obtained in step (3) is subjected to solid-liquid separation, and the solid is dried at 70-90° C. to a moisture content of 15-20%; (5) Puffing: The product of step (4) is stirred and mixed for 5-7 minutes, allowed to stand for 20-40 minutes; and then puffed at 60-150° C. to obtain a puffed food raw material rich in water-soluble polysaccharides.

7. The preparation method according to claim 6, characterized in that The puffing conditions are: screw speed 70-90r / min, puffing temperature 70-80℃ in zone I, 100-120℃ in zone II, and 130-150℃ in zone III.

8. Use of the puffed food raw material rich in water-soluble polysaccharides as described in any one of claims 1 to 5 in the preparation of spicy strips, shaqima, brown rice rolls or biscuits.

9. The use according to claim 8, characterized in that The preparation process of spicy strips is as follows: puffed food raw materials are cut into strips, seasonings, concentrated liquid and the puffed food raw materials after cutting are stirred and immersed to obtain spicy strips, and the liquid separated by solid and liquid is concentrated by heating to obtain concentrated liquid, and the relative density of the concentrated liquid is 1.1-1.2.

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