A processing technology for instant quinoa sprout pre-prepared food.

Abstract

This invention discloses a processing technology for ready-to-eat quinoa sprout pre-prepared food, belonging to the technical field of quinoa sprout compound food. The processing technology includes three steps: S1. Raw material pretreatment, i.e., quinoa sprouts are washed, blanched, cooled, enzymatically hydrolyzed, freeze-dried and pulverized to obtain powder; starch-containing ingredients are pre-gelatinized and colloidally modified to obtain modified starch; oil-containing powder is emulsified and mixed with modified starch to form a first modified starch-oil complex; S2. Raw material mixing, i.e., after mixing quinoa sprout powder and modified starch, calcium chloride, transglutaminase, and the first modified starch-oil complex are added; S3. Granulation and solidification, i.e., granulation with trehalose and other ingredients, followed by microwave and gradient drying. The processing technology provided by this invention can solve the problems of clumping, oxidative stratification, and structural cracking in quinoa compounded with high-starch and high-oil ingredients, significantly improving product quality.

Description

Technical Field

[0001] This invention belongs to the field of quinoa sprout compound food technology, specifically a processing technology for a ready-to-eat quinoa sprout pre-prepared food. Background Technology

[0002] Quinoa sprouts are rich in protein, dietary fiber, polyphenols, and minerals, making them a high-quality functional ingredient in compound foods. When combined with high-starch ingredients (such as oat flour and corn starch), they can enhance the feeling of fullness in the product; when combined with high-fat ingredients (such as nut powder and seed powder), they can enrich the flavor profile, theoretically achieving a synergistic optimization of nutrition and taste.

[0003] However, the following technical defects exist in actual compounding:

[0004] Firstly, when combined with high-starch ingredients: the water absorption and swelling rate of quinoa sprout ultrafine powder differs significantly from that of starchy ingredients (starch absorbs water 2-3 times faster than quinoa sprout powder). During brewing, the starch rapidly absorbs water and gelatinizes to form a viscous film that coats the quinoa sprout powder particles, resulting in a solubility rate of less than 50% within 2 minutes. Furthermore, it easily forms hard lumps, and the uneven heating inside these lumps creates a "raw core" (undissolved starch), severely affecting the smoothness of the texture.

[0005] Secondly, when combined with high-fat ingredients: the residual lipoxygenase in quinoa sprouts (which retains 5-10% activity after traditional blanching) will catalyze the oxidation of unsaturated fatty acids in high-fat ingredients, resulting in a significant increase in acid value and a slight rancid taste after the product has been stored for a certain period of time; at the same time, due to the density difference between the oil and water phases, the oil tends to float to the surface and form layers after brewing, which disrupts the uniformity of the product.

[0006] In practice, to address the above problems, the inventors first implemented pregelatinization modification to address the issue of starch absorbing water too quickly, and also added antioxidants to address the issue of oil oxidation. However, these two improvements were limited to the level of a single raw material and failed to solve the synergistic defects of the compound system.

[0007] Firstly, the interfacial compatibility between modified starch and quinoa sprout fiber is insufficient: although the water absorption rate of starch decreases after pregelatinization, the binding force between the molecular chain and the hydroxyl groups on the surface of quinoa fiber is weak. When brewing, it is easy to detach from the fiber skeleton due to the impact of water flow, and aggregate to form local high concentration areas, resulting in a solubility rate of less than 65% after 2 minutes and a clumping rate of more than 25%.

[0008] Secondly, the network synergy between modified oils and modified starch is lacking: Although the oxidation rate of oils is slowed down after emulsification modification, the interfacial tension with modified starch is large, and they cannot be effectively anchored in the starch network. Moreover, the density difference with the quinoa system is not fundamentally eliminated. After 6 months of storage, the floating rate of oils exceeds 15%, and the acid value exceeds 0.6 mg / g.

[0009] Third, the networks of the two interfere with each other: the colloidal network of modified starch and the interfacial film of oil emulsion compete for binding, causing the system to crack due to uneven stress during the drying process.

[0010] Therefore, we urgently need to develop a process that can coordinate the interaction of quinoa sprouts, modified starch, and modified oils to solve the above-mentioned synergy defects at the system level. Summary of the Invention

[0011] The purpose of this invention is to provide a processing technology for ready-to-eat quinoa sprout pre-prepared food. Using the dietary fiber of quinoa sprouts as the framework and combining it with exogenous functional colloids, a synergistic dispersion structure of "starch-oil-quinoa sprout powder" is formed through the synergistic design of raw material pretreatment, emulsification and compounding processes. This simultaneously solves the problems of clumping, oxidative stratification and colloidal aggregation, particle sedimentation and network cracking during processing.

[0012] The objective of this invention is achieved through the following technical solution:

[0013] A processing method for a ready-to-eat quinoa sprout pre-prepared food includes the following steps:

[0014] S1. Raw material pretreatment:

[0015] S11. Quinoa sprouts are washed, blanched, cooled, enzymatically hydrolyzed, freeze-dried, and pulverized to 100-200 mesh to obtain quinoa sprout powder.

[0016] Take another starchy ingredient, add plant antioxidant extract and pregelatinize it. Then add the basic colloid formed by xanthan gum and sodium caseinate to the pregelatinized starch, and slowly add sodium pyrophosphate solution. After stirring thoroughly, adjust the pH of the system to 6.5-7.0 with citric acid. After mixing thoroughly, pulverize to 100-200 mesh to obtain modified starch.

[0017] The modified starch is divided into three parts: first modified starch, second modified starch, and third modified starch.

[0018] S12. First, mix the oil-containing powder with emulsifier and natural antioxidant, then emulsify by high-speed shearing and high-pressure homogenization to obtain an emulsion. Then, add the first modified starch, gum arabic and octenyl succinate starch ester to the emulsion and mix thoroughly to obtain the first modified starch-oil complex.

[0019] S2. Raw material mixing:

[0020] First, quinoa sprout powder and second modified starch are thoroughly mixed to obtain a first mixture; then calcium chloride and transglutaminase are added to the first mixture, and after thorough mixing, the first modified starch-oil complex, lysophosphatidylcholine, and food-grade silica coated with third modified starch are added, and after thorough stirring, a second mixture is obtained.

[0021] S3. Granulation and curing:

[0022] Trehalose and a humectant were added to the second mixture, and after being fully dispersed, the mixture was granulated, followed by microwave treatment and gradient drying to obtain a pre-prepared food.

[0023] This invention uses quinoa sprouts as its core and employs a three-stage process—raw material pretreatment, raw material mixing, and granulation and solidification—to construct a three-dimensional stable system of "quinoa dietary fiber framework / modified starch / first modified starch-oil complex." This effectively resolves the contradiction in combining quinoa with high-starch and high-oil foods. The specific process logic is as follows:

[0024] The raw material pretreatment stages (S11 and S12) lay the foundation for system stability. After enzymatic hydrolysis and freeze-drying, quinoa sprouts retain their dietary fiber skeleton intact, and some insoluble fibers are converted into soluble fibers. This structure serves as a natural anchoring carrier for the subsequent colloidal network, and the colloidal properties of the soluble fibers can buffer the stress caused by starch swelling due to water absorption. If this treatment is omitted, the fibers cannot form a porous structure, and the starch and oil particles will be unevenly dispersed due to the lack of anchoring, significantly exacerbating the clumping problem.

[0025] Simultaneously, starchy ingredients undergo pregelatinization and colloidal compound modification: xanthan gum and sodium caseinate form a basic colloid, sodium pyrophosphate breaks up starch agglomeration through competitive hydrogen bonding, and citric acid adjusts the pH to a suitable range to enhance the electrostatic repulsion of the colloid, ultimately matching the starch water absorption rate with the water absorption characteristics of quinoa fiber.

[0026] Oil-containing powders are emulsified and coated with starch to form a complex: the emulsifier reduces the interfacial tension, and the gum arabic and the first modified starch work together to form an oil-starch coating layer, anchoring the oil particles in the starch network and offsetting the sedimentation tendency caused by density difference from the source.

[0027] In the raw material mixing stage (S2), a reinforced network structure is constructed based on the pretreatment. Quinoa sprout powder and modified starch first form a fiber-starch primary network; calcium chloride activates transglutaminase (TG enzyme), catalyzing the formation of covalent bonds between colloidal molecules to enhance gel strength; the silica-balanced system coated with a third modified starch balances the density of the oil complex, and in conjunction with lysophosphatidylcholine, enhances interfacial compatibility, reduces particle settling rate, and achieves a triple anti-settling synergy of "network load-density balance-interfacial stability".

[0028] The granulation and solidification stage (S3) fosters network stability. Trehalose fills the network pores to reduce shrinkage stress, while humectants form hydrogen bonds with the colloids to enhance moisture retention. Microwave pretreatment kills surface microorganisms, and gradient drying controls the moisture difference between the inside and outside of the particles, preventing network cracking.

[0029] Through the synergistic effect of the above three stages, the prepared pre-prepared food comprehensively resolves the core contradiction between quinoa sprouts and high starch and high oil content.

[0030] Furthermore, the synergistic effect of key components in the three stages supports the achievement of the above-mentioned effects:

[0031] Xanthan gum slows down starch water absorption, sodium caseinate enhances oil compatibility, and sodium pyrophosphate breaks up starch agglomeration. The three complement each other. If xanthan gum is lacking, starch absorbs water too quickly and easily coats quinoa sprout powder to form clumps. If sodium caseinate is lacking, oil precipitation is obvious. If sodium pyrophosphate is lacking, starch agglomeration leads to local incomplete dissolution.

[0032] The combination of TG enzyme and calcium chloride is equally crucial: TG enzyme strengthens the network's carrying capacity through covalent linkage, while calcium chloride serves as its active activator. Without both, the network relies solely on hydrogen bonds, making it difficult to carry oil particles and exacerbating sedimentation problems; without calcium chloride, the cross-linking strength is insufficient, making it prone to cracking during drying.

[0033] Synergistic effect of gum arabic and silica: Gum arabic enhances the strength of the oil-first modified starch interfacial film, while silica balances the system density. Insufficient gum arabic leads to increased oil precipitation; insufficient silica causes oil to float due to density differences.

[0034] The hydrophilic starch chains of octenyl succinate starch ester (OSS) can bind to the hydroxyl groups on the surface of quinoa fibers, enhancing the anchoring effect of the first modified starch-oil complex in the fiber skeleton, preventing particle detachment due to water flow impact during brewing, and ensuring uniform dispersion.

[0035] It is important to emphasize that this process is specifically designed to suit the characteristics of quinoa sprouts. The porous structure and suitable proportion of soluble fiber in quinoa dietary fiber can simultaneously perform the dual functions of "rigid framework + colloidal buffer," which is difficult for other plant fibers to replace. For example, although wheat sprout fiber has a high porosity, its proportion of soluble fiber is less than 5% (quinoa can reach 12-15%), which cannot buffer the stress of starch absorbing water and swelling, causing the particles to easily crack due to stress concentration. Alfalfa sprout fiber is too elastic but not rigid enough. After the same enzymatic hydrolysis treatment, the framework is prone to collapse, and the dispersion uniformity of the first modified starch-oil complex decreases by more than 40%, all of which cannot support the stable distribution of the first modified starch-oil complex.

[0036] Meanwhile, the starch modification parameters are customized for the water absorption characteristics of quinoa sprout powder. Quinoa sprout powder needs 8-10 minutes to reach water saturation, while oat flour only needs 4-5 minutes and corn starch needs 3-4 minutes. If the invented starch modification process is not used and simple gelatinized starch (i.e., without pregelatinization and colloidal compound treatment) is used directly, its water absorption rate will be 2-3 times faster than that of quinoa sprout powder due to the lack of regulation such as the delay of xanthan gum and the dispersion of sodium pyrophosphate, resulting in a significant increase in the clumping rate and an inability to match the water absorption rhythm.

[0037] In addition, the oil processing solution is specifically designed to address the residual lipoxygenase activity unique to quinoa (8-10% activity is still retained after blanching), while the residual lipoxygenase in wheatgrass, barleygrass and other plants is less than 1% after the same blanching, so there is no need for the synergistic system of modified starch coating + compound antioxidants; if this process is used for these raw materials, the excessive coating will hinder the release of oil and increase the loss rate of flavor substances.

[0038] Therefore, this process technology chain is only suitable for quinoa sprout and stalk compounding scenarios, reflecting a precise response to their characteristics.

[0039] As one possible implementation method of this application, in step S11, the parameters of the enzymatic hydrolysis step are as follows: a composite enzymatic hydrolysis system of 0.4-0.6 wt% cellulase and 0.2-0.3 wt% xylanase is used, with a mass ratio of 1:1-2; the hydrolysis temperature is 40-50℃; and the time is 10-20 min. Single cellulase can only degrade cellulose and cannot decompose hemicellulose, resulting in residual fiber toughness, reduced binding rate with colloids, insufficient network support, and easy local gelatinization of starch during brewing (significant clumping). By limiting the enzymatic hydrolysis conditions, the above problems can be effectively solved.

[0040] As one possible implementation of this application, in step S11, a fiber hardness pre-test is added before enzymatic hydrolysis: the hardness value of quinoa sprouts is measured using a texture analyzer. If the hardness is >40N, the enzymatic hydrolysis time is 10-15 min; if the hardness is <30N, the enzymatic hydrolysis time is 18-20 min. Due to differences in planting humidity (e.g., drought vs. rain), the fiber hardness of quinoa sprouts fluctuates greatly (25-45N). Fixing the enzymatic hydrolysis time leads to insufficient hydrolysis of hard fibers (hard fiber residue, resulting in reduced binding rate) and excessive hydrolysis of soft fibers (skeletal breakage, reduced network strength), resulting in unstable products.

[0041] This invention, by introducing a texture analyzer for pre-inspection and limiting the enzymatic hydrolysis time, enables targeted enzymatic hydrolysis, effectively reducing the difference in the degree of degradation of secondary fibers and improving product stability.

[0042] As some possible implementations of this application, in step S2, the food-grade silica coated with the third modified starch is replaced with food-grade silica coated with a chitosan and third modified starch composite solution; the mass ratio between the chitosan and the third modified starch is (2-5):(7-10).

[0043] When pure modified starch is used to coat silica, its compatibility with the xanthan gum-sodium caseinate network is poor. Due to the lack of covalent bonding, silica easily aggregates and lacks antibacterial properties, increasing the risk of mold contamination during storage. This application introduces chitosan, which forms covalent crosslinks with xanthan gum (carboxyl groups), effectively improving the uniformity of silica dispersion. Simultaneously, the antibacterial properties of chitosan synergize with the natural antioxidant—rosemary extract—effectively reducing mold contamination rates and extending shelf life. Furthermore, chitosan forms hydrogen bonds with the hydroxyl groups of quinoa fibers, anchoring silica within the fiber pores and enhancing the network's load-bearing capacity.

[0044] As some possible embodiments of this application, 0.4-7 wt% gum arabic (based on the total mass of the composite solution) is added to the chitosan-modified starch composite solution; food-grade silica coated with chitosan and modified starch composite solution is mixed with 0.08-0.12 wt% maltodextrin (based on the mass of silica).

[0045] This application introduces gum arabic into a chitosan-third modified starch composite solution, utilizing its polyhydroxy structure to form hydrogen bonds with chitosan and modified starch, thereby enhancing the cohesive force of the coating layer and reducing peeling. Simultaneously, the coated silica is mixed with maltodextrin, and the lubricating properties of maltodextrin are used to reduce interparticle friction and improve dispersion smoothness.

[0046] As one possible implementation of this application, in step S3, 0.08-0.12 wt% magnesium stearate (based on the total mass of the humectant) is added to the humectant.

[0047] As one possible implementation of this application, in step S12, gum arabic is replaced with a compound of gum arabic and pectin, with a mass ratio of 2-5:1; 0.03-0.06 wt% sodium citrate (based on the total mass of the compound) is added to the gum arabic and pectin compound.

[0048] Gum arabic alone has insufficient coating power for high-oil (50-60%) systems (increasing oil extraction rate), and pectin easily gels under acidic conditions (pH < 6.0), leading to large viscosity fluctuations and affecting uniformity. This application specifies a combination of gum arabic and pectin. The pectin carboxyl groups enhance the hydrogen bonding with starch, reducing oil extraction rate; sodium citrate buffers the pH, thus reducing viscosity fluctuations.

[0049] As one possible implementation of this application, the chitosan is activated by a sodium citrate solution. Sodium citrate is a neutral activator that can enhance the amino activity of chitosan without affecting the pH stability of the system. It works synergistically with the pH buffer system regulated by citric acid in S11 to ensure stable TG enzyme activity and unaffected crosslinking efficiency.

[0050] As one possible implementation of this application, in step S3, the gradient drying step is as follows: first, drying at 25-35℃ for 1-1.5 h, then raising the temperature to 38-42℃ for 1-1.5 h, and finally raising the temperature to 44-46℃ for 1-1.5 h. Gradient drying can effectively reduce excessive network shrinkage stress and reduce the crack rate.

[0051] As one possible implementation of this application, 0.015-0.25 wt% glucose oxidase and 0.08-0.12 wt% horseradish peroxidase (based on the weight of quinoa sprouts) are added to the S11 complex enzymatic hydrolysis system.

[0052] When S11 xanthan gum and sodium caseinate form a basic colloid, add 0.2-0.5 wt% β-cyclodextrin (based on the total mass of the colloid).

[0053] Quinoa sprouts contain volatile substances such as quinoa aldehydes that produce a distinct grassy smell. If not treated specifically, this will significantly affect the flavor balance of the product.

[0054] This application introduces glucose oxidase and horseradish peroxidase during the enzymatic hydrolysis stage. The two enzymes work synergistically to directionally oxidize and decompose the active groups of grassy odor substances such as quinoa aldehyde, reducing the intensity of the odor at its source. During the colloid formation stage, β-cyclodextrin is added. Its molecular cavity can specifically encapsulate trace amounts of incompletely decomposed odor substances, preventing their release during storage and brewing. This application forms a closed loop through oxidative decomposition and encapsulation adsorption, thoroughly removing odors while avoiding flavor imbalances that may result from a single odor removal method. Furthermore, the combination of β-cyclodextrin and the colloidal network enhances system stability, achieving a dual optimization of "odor removal and stability," and is only suitable for raw materials such as quinoa containing specific volatile substances.

[0055] As some possible implementations of this application, the mass ratio of quinoa sprout powder, starch-containing ingredients, and oil-containing powder is quinoa sprout (45-60): (20-30): (15-25), and the mass content of unsaturated fatty acids in the oil-containing powder is ≤60%. This application clarifies that the mass ratio of the three is determined based on the pore capacity of quinoa dietary fiber, the network carrying capacity limit of starch colloids, and the anchoring requirements of oil particles: an imbalance in the ratio will either lead to excessive starch causing excessive gelatinization and clumping, excessive oil exceeding the fiber anchoring capacity and causing stratification, or an excessively high proportion of quinoa leading to insufficient system support. At the same time, limiting the unsaturated fatty acid content in the oil-containing powder to ≤60% can match the scavenging capacity of the antioxidant system and avoid oxidative deterioration during long-term storage.

[0056] It is worth noting that the high-starch ingredients mentioned in this invention refer to ingredients with a starch content between 60% and 85%. If the starch content is less than 50%, the water absorption and swelling characteristics are weak, and the risk of clumping is inherently low, so there is no need for the complex modification process of this invention (such as pregelatinization and colloidal compounding treatment). Only when the starch content reaches a certain threshold will the problem of rapid water absorption and gelatinization become prominent, and only then will it be suitable for the modification logic of this invention.

[0057] Compared with the prior art, the beneficial effects of the present invention are:

[0058] 1. The process of this invention achieves a breakthrough improvement in brewing performance and storage stability by constructing a three-dimensional stable system of "quinoa dietary fiber skeleton / modified starch / first modified starch-oil complex": the solubility rate can reach more than 97% in 2 minutes, the clumping rate is less than 0.7%, the acid value is ≤0.23mg / g after 6 months of storage, the oil floating rate is ≤0.6%, and the cracking rate is ≤1.5%, which comprehensively solves the problems of clumping, oxidative stratification and structural cracking when quinoa sprouts are compounded with high starch and high oil ingredients.

[0059] 2. This invention significantly improves the high humidity stability of the system by coating silica with a composite of chitosan and a third modified starch, and by optimizing it with gum arabic and maltodextrin: after 6 months of storage at 70% relative humidity, the silica aggregation rate is only 3.5-4.1%. At the same time, the covalent cross-linking of chitosan and xanthan gum enhances the network carrying capacity, reducing the sedimentation deviation to 0.07 g / cm³, and further inhibiting oil stratification.

[0060] 3. This invention effectively solves the grassy taste problem of quinoa sprouts by introducing a synergistic deodorization system of "glucose oxidase-horseradish peroxidase + β-cyclodextrin". The oxidative decomposition in the enzymatic hydrolysis stage and the inclusion adsorption in the colloidal stage form a closed loop. While removing the odor, β-cyclodextrin also enhances the stability of the colloidal network, achieving dual optimization of deodorization and stability. Detailed Implementation

[0061] Example 1

[0062] S1. Raw material pretreatment.

[0063] S11.

[0064] Quinoa sprout processing: Take 500 parts by weight of quinoa sprouts, wash them, blanch them in 95℃ hot water for 30 seconds, and immediately cool them to room temperature in an ice bath; the fiber hardness is measured to be 35N using a texture analyzer; add 2.5 parts by weight of cellulase and 1.5 parts by weight of xylanase, enzymatically hydrolyze them in a 45℃ water bath for 15 min, and inactivate the enzymes in a 85℃ water bath for 10 min; freeze-dry (pre-freeze at -35℃ for 2 h, freeze-dry under vacuum of 15 Pa until moisture content ≤5%) and then pulverize to 150 mesh to obtain quinoa sprout powder.

[0065] Preparation of modified starch: Take 250g of oat flour (starch-containing ingredient, starch content 72%), add 0.075g of food-grade rosemary extract, and extrude and pregelatinize at 115℃. Then, add 0.75g of xanthan gum and 0.5g of sodium caseinate dissolved in a 50℃ water bath to the pregelatinized starch to form a basic colloid. Slowly add sodium pyrophosphate solution (0.125g of sodium pyrophosphate dissolved in 12.5g of water, all added), and stir at 500r / min for 15 min. Adjust the pH of the system to 6.8 with 10wt% citric acid solution, mix thoroughly, and pulverize to 150 mesh to obtain modified starch. Divide the modified starch into three parts: first modified starch, second modified starch, and third modified starch. The sum of the masses of the three parts is equal to the mass of the prepared modified starch.

[0066] S12. Preparation of the first modified starch-oil complex:

[0067] Take 250g of walnut powder (containing oil powder, 55% unsaturated fatty acids), mix it with 2.5g of compound emulsifier (soybean lecithin: sucrose ester = 3:1, mass ratio), 0.05g of tea polyphenols, add 200g of water, and emulsify at 10000r / min and 50℃ for 5 min; transfer to a high-pressure homogenizer and homogenize twice at 25MPa and 50℃ (oil particle size ≤3μm) to obtain an emulsion; add 90g of first modified starch, 0.45g of gum arabic and 0.23g of OSS to the emulsion, stir at 100r / min for 5 min, then stir at 300r / min for 5 min to obtain the first modified starch-oil complex.

[0068] S2. Raw material mixing: Take 500g of quinoa sprout powder and the second modified starch (i.e., the remaining amount after subtracting the first and third modified starches from the modified starch prepared in step S11), add it to a vacuum mixer (vacuum degree -0.08MPa), mix at 20r / min for 10 min to obtain the first mixture; add 0.075g of calcium chloride and 0.15g of TG enzyme to the first mixture, stir at 40℃ and with a moisture content of 14.5-15.5% (achieved by adding or subtracting water) for 15 min; add all of the first modified starch-oil complex obtained in step S12, 0.6g of lysophosphatidylcholine, and 3.6g of silica coated with the third modified starch, stir at 300r / min for 5 min to obtain the second mixture.

[0069] The preparation method of the third modified starch-coated silica is as follows:

[0070] 10g of the third modified starch was added to 100g of deionized water and dissolved completely in a 50℃ water bath to form a uniform colloidal solution. Then, 3.6g of food-grade silica was added and mixed thoroughly (500r / min, 50℃, 30 min). Subsequently, it was spray-dried (inlet air temperature 180℃, outlet air temperature 80℃, atomization pressure 0.3MPa) to obtain silica coated with the third modified starch.

[0071] S3 Granulation and solidification: Add 12g trehalose and 18.018g humectant (12g glycerin, 6g sorbitol, 0.018g magnesium stearate) to the second mixture, disperse at 500r / min for 5 min, then granulate using a gyratory granulator (2mm screen); microwave at 500W for 30 seconds; gradient drying (drying at 30℃ and 60% relative humidity for 1h → drying at 40℃ for 1h → drying at 45℃ for 1h) to obtain pre-prepared food (moisture content ≤7%).

[0072] Example 2

[0073] Compared to Example 1, the following adjustments are made:

[0074] (1) Raw material adjustment:

[0075] Main ingredients: 550g quinoa sprouts, 250g corn starch (a starchy food with a starch content of 75%), 200g almond powder (an oily powder with 58% unsaturated fatty acids).

[0076] Auxiliary ingredients: 2.75g cellulase, 1.65g xylanase.

[0077] (2) Process adjustment:

[0078] S11 Enzymatic hydrolysis: The fiber hardness of quinoa sprouts was 42, and the enzymatic hydrolysis time was 12 min (40℃).

[0079] S3 Gradient drying: 35℃, 60% relative humidity, drying for 1.2h → 42℃, drying for 1.2h → 46℃, drying for 1.2h.

[0080] The remaining components and steps are the same as in Example 1.

[0081] Example 3

[0082] Compared to Example 1, the following adjustments are made:

[0083] S11 Enzymatic hydrolysis: Add 0.1g glucose oxidase and 0.05g horseradish peroxidase to the compound enzymatic hydrolysis system, and react with cellulase and xylanase at 45℃ for 15 min.

[0084] S11 Colloid formation: Add 0.75g β-cyclodextrin to the basic colloid formed by xanthan gum-sodium caseinate and stir simultaneously in a 50℃ water bath for 10 min.

[0085] The remaining components and steps are the same as in Example 1.

[0086] Example 4

[0087] Compared to Example 3, the following adjustments are made:

[0088] In S2, “silica coated with third modified starch” is replaced with “silica coated with chitosan-third modified starch composite”. The preparation method is as follows: Take 3.6g of food-grade silica, disperse it in chitosan-third modified starch composite solution (1.08g chitosan + 2.52g third modified starch + 32.4g water), add 0.144g gum arabic, stir at 50℃ for 30 min, and then spray dry (inlet air temperature 180℃, outlet air temperature 80℃, atomization pressure 0.3MPa) to obtain coated silica, and then mix it with 0.0036g maltodextrin and add it to the second mixture.

[0089] The remaining components and steps are the same as in Example 3.

[0090] Example 5

[0091] Compared to Example 4, the following adjustments are made:

[0092] In S12, "gum arabic" is replaced with "a compound of gum arabic and pectin" (0.3375g gum arabic + 0.1125g pectin), and 0.000225g sodium citrate is added to the compound.

[0093] The remaining components and steps are the same as in Example 4.

[0094] Example 6

[0095] In Example 5, although quinoa sprout pre-prepared food is rich in dietary fiber, minerals and functional ingredients, its natural protein content is low. Therefore, in actual implementation, it is necessary to add protein powder (such as whey protein or soy protein isolate) to increase the protein content of the product, significantly enhance nutritional balance, and meet the high protein needs of fitness enthusiasts, meal replacement users and other scenarios.

[0096] However, if protein powder is added directly based on Example 5, it will conflict with the original system, resulting in a decrease in the performance of the final food product, as detailed below:

[0097] (1) Conflict in water absorption rhythm: Protein powder (especially whey protein) can absorb water to saturation in only 2-3 minutes, much faster than quinoa sprout powder (8-10 minutes) and modified starch (8-10 minutes). This causes the protein to coagulate rapidly during brewing, coating the quinoa sprout powder and forming clumps, with the clumping rate increasing from 0.1% to over 25%. Based on this, before adding protein powder, a compound enzymatic hydrolysis (alkaline protease + flavor protease) is used to break down the large protein molecules into small peptides, reducing the water absorption rate to 8-10 minutes. Secondly, after enzymatic hydrolysis, octenyl succinate starch ester (OSS) is compounded with maltodextrin for encapsulation to further delay water absorption.

[0098] (2) Interference with the original colloidal network: The amino groups of proteins and the carboxyl groups of xanthan gum easily form electrostatic bonds, which destroys the synergistic effect of "xanthan gum-sodium caseinate-sodium pyrophosphate", resulting in a decrease in the carrying capacity of the starch network and an increase in the oil floating rate from 0.2% to 12.8%. Based on this, the amount of sodium caseinate was increased to 0.8g to enhance the interfacial affinity by utilizing its homology with proteins.

[0099] (3) Insufficient thermal stability: Proteins are prone to denaturation and aggregation during microwave treatment (500W, 30 seconds) and gradient drying (46℃), forming a hard core. The solubility drops from 98.2% to below 75.9%. Based on this, the microwave treatment power is reduced to 400W and the time is shortened to 20 seconds. Secondly, the maximum temperature of gradient drying is reduced to 44℃ and the drying time of the third stage is extended to 1.5 h.

[0100] (4) Denaturation and precipitation during hot water brewing: When brewed with hot water at 80℃, some protein peptides undergo thermal denaturation, resulting in a decrease in the interfacial binding force with the oil-starch complex, and the oil floating rate increases to over 1%. Based on this, 0.05g of lysophosphatidylcholine is added to S2 to enhance the interfacial stability at high temperatures; secondly, sucrose ester is added during granulation to improve high-temperature dispersibility.

[0101] The specific process of Example 6 is as follows:

[0102] S1. Raw material pretreatment.

[0103] S11. Basic raw material processing.

[0104] Preparation of quinoa sprout powder: Same as in Example 5.

[0105] Preparation of modified starch: Take 250g of oat flour, add 0.075g of rosemary extract, and extrude and pregelatinize at 115℃; add 0.75g of xanthan gum and 0.8g of sodium caseinate dissolved in a 50℃ water bath to the pregelatinized starch to form a basic colloid, slowly add sodium pyrophosphate solution (0.125g sodium pyrophosphate dissolved in 12.5g water), and stir at 500r / min for 15 min; adjust the pH of the system to 6.9 with 10wt% citric acid solution, and pulverize to 150 mesh to obtain modified starch. Divide the modified starch into three parts: first modified starch, second modified starch, and third modified starch. The sum of the masses of the three parts is equal to the mass of the prepared modified starch.

[0106] S12. Protein powder pretreatment and encapsulation: Take 100g of whey protein powder (protein content 80%), add 500g of deionized water, stir to dissolve, then add 0.3g of alkaline protease and 0.2g of flavor protease, enzymatically hydrolyze in a 50℃ water bath for 30min, and inactivate the enzyme at 85℃ for 10min; cool to 40℃, add 300g of compound wall material solution (OSS 200g + maltodextrin 100g dissolved in 1000g water), shear at 10000r / min for 10min, and spray dry (inlet air 180℃, outlet air 80℃, atomization pressure 0.3MPa) to obtain encapsulated protein peptide powder (moisture ≤5%).

[0107] S13. Preparation of the first modified starch-oil complex (same as Example 5).

[0108] S2. Raw material mixing: Take 500g of quinoa sprout powder and the second modified starch (i.e., the remaining amount after subtracting the first and third modified starches from the modified starch prepared in step S11), add 100g of encapsulated protein peptide powder, and stir in a vacuum mixer (-0.08MPa) at 300r / min for 10 min to obtain the first mixture; then add 0.075g of calcium chloride and 0.15g of TG enzyme to the first mixture, and stir at 40℃ with a moisture content of 14.5-15.5% (achieved by adding or subtracting water) for 15 min; then add the first modified starch-oil complex prepared in S13, 0.65g of lysophosphatidylcholine, and silica coated with chitosan-third modified starch complex (same as in Example 5), and stir at 300r / min for 8 min to obtain the second mixture.

[0109] S3. Granulation and solidification: Add 12g trehalose, 18.018g humectant (same as in Example 5), and 5g sucrose ester to the second mixture, disperse at 500r / min for 5 min, and then granulate using a 2mm sieve; subsequently microwave at 400W for 20 seconds; finally, perform gradient drying (drying at 30℃ and 60% relative humidity for 1.5h → drying at 40℃ for 1.5h → drying at 44℃ for 1.5h) to obtain the pre-prepared food (moisture content ≤7%).

[0110] Performance indicators: 2-minute solubility 98.4%; clumping rate 0.2%; 6-month acid value 0.19 mg / g; oil floating rate: 0.2%;

[0111] In summary, Example 6, while adding protein powder to enhance nutrition, maintained the stability of the original system through targeted improvements, and its performance was as significant as that of Example 5.

[0112] Comparative Example 1

[0113] Compared to Example 1, the starch processing technology was adjusted as follows:

[0114] Take 250g of oat flour (containing starch, starch content 72%), add 0.075g of food-grade rosemary extract, extrude and pregelatinize at 115℃, and pulverize to 150 mesh to obtain unmodified starch.

[0115] The remaining components and steps are the same as in Example 1.

[0116] Comparative Example 2

[0117] Compared to Example 1, the preparation method in step S12 has been adjusted, specifically as follows:

[0118] Take 250g of walnut powder (containing oil powder, 55% unsaturated fatty acids), mix it with 2.5g of compound emulsifier (soy lecithin: sucrose ester = 3:1, mass ratio) and 0.05g of tea polyphenols, add 200g of water, and emulsify at 10000r / min and 50℃ for 5 min; transfer it to a high-pressure homogenizer and homogenize twice at 25MPa and 50℃ (oil particle size ≤3μm) to obtain an emulsion, and directly enter step S2.

[0119] The remaining components and steps are the same as in Example 1.

[0120] Comparative Example 3

[0121] Compared to Example 1, the preparation method in step S12 has been adjusted, specifically as follows:

[0122] Take 250g of walnut powder (containing oil powder, 55% unsaturated fatty acids), mix it with 2.5g of compound emulsifier (soybean lecithin: sucrose ester = 3:1, mass ratio) and 0.05g of tea polyphenols, add 200g of water, and emulsify at 10000r / min and 50℃ for 5 min; transfer to a high-pressure homogenizer and homogenize twice at 25MPa and 50℃ (oil particle size ≤3μm) to obtain an emulsion; add 0.45g of gum arabic and 0.23g of OSS to the emulsion, stir at 100r / min for 5 min, then stir at 300r / min for 5 min to obtain an oil complex, and directly proceed to step S2.

[0123] The remaining components and steps are the same as in Example 1.

[0124] Comparative Example 4

[0125] Compared to Example 1, calcium chloride and TG enzyme are not added in S2, but everything else is the same as in Example 1.

[0126] Comparative Example 5

[0127] Compared to Example 1, S2 does not contain the third modified starch-coated silica, but all other aspects are the same as in Example 1.

[0128] Comparative Example 6

[0129] Quinoa sprout processing: Same as in Example 1 (washing, blanching, cooling, enzymatic hydrolysis, freeze drying, pulverizing) to obtain quinoa sprout powder (only basic pretreatment is retained, and no synergistic design with other components is formed).

[0130] Starch treatment: Pregelatinization only (115℃ extrusion, without xanthan gum, sodium caseinate, or sodium pyrophosphate modification), pulverized to 150 mesh (water absorption rate not adjusted).

[0131] Oil treatment: High-speed shear emulsification and high-pressure homogenization were performed using only a compound emulsifier (same as in Example 1) (without modified starch or gum arabic coating, and no first modified starch-oil complex was formed) to obtain an emulsion.

[0132] Conventional mixing: Quinoa sprout powder, unmodified starch, and emulsion are directly mixed, and calcium chloride and TG enzyme (same dosage as in Example 1) are added. After stirring evenly, the mixture is granulated; after microwave treatment, gradient drying is performed (same as in Example 1) to obtain pre-prepared food.

[0133] Experimental Example

[0134] The pre-prepared foods prepared in Examples 1-5 (using the process of this invention) were compared with the pre-prepared foods prepared in Comparative Examples 1-6 (lacking key technical features) to demonstrate the significant progress of this invention in solving problems of clumping, oxidation, flavor and stability. The specific experiments and experimental data (as shown in Table 1) are as follows.

[0135] 1. Brewing performance:

[0136] 2-min solubility: Take 10g of sample, add 100mL of 80℃ hot water, stir for 2 min (100r / min), then pass through a 100-mesh sieve and calculate the mass percentage of dissolved matter passing through the sieve.

[0137] Agglomeration rate: The percentage of the total mass of the sample formed by hard lumps with a diameter >3mm after stirring.

[0138] 2. Storage stability:

[0139] Acid value: After sealing the sample, store it at 25°C for 6 months and then determine the acid value.

[0140] Oil floating rate: Take 10g of the stored pre-prepared food, add 100mL of 80℃ deionized water, stir for 2min until completely dispersed, pour into a 100mL stoppered graduated cylinder, let stand for 30min (room temperature 25℃), and calculate the proportion of the mass of the floating oil in the upper layer to the total oil mass.

[0141] Crack rate: A certain number of particle samples are randomly selected, and the proportion of cracked particles to the total number of particles is counted.

[0142] Crack rate determination method: Select 100 pre-prepared food granules after storage (ensure the granules are intact and unbroken), and observe the surface of the granules using a stereomicroscope (magnification 10×). If cracks with a length > 0.5 mm or a depth > 0.1 mm are present, they are recorded as "cracked granules". Calculation: Crack rate (%) = (number of cracked granules / 100) × 100.

[0143] Sedimentation deviation: Measure the density of the upper and lower layers of the sample after storage and calculate the density difference.

[0144] 3. Flavor evaluation: Ten professional evaluators were organized to score the grassy smell of the samples using a 1-10 scale, with 10 points indicating no off-odor.

[0145] 4. High humidity stability: The sample was stored in an environment with 70% relative humidity for 6 months, and the proportion of silica aggregates to the total number of particles was observed under a microscope.

[0146] Table 1:

[0147]

[0148] Conclusion: As can be seen from the data in Table 1, Examples 1-5 using the process of this invention are significantly superior to Comparative Examples 1-6 lacking the key technology in terms of brewing performance, storage stability, flavor, and high humidity adaptability. Specific analysis is as follows:

[0149] 1. From the perspective of brewing performance:

[0150] The dissolution rates of Examples 1-5 all exceeded 97% within 2 minutes, with a clumping rate of less than 0.7%; while the dissolution rates of Comparative Examples 1-6 were only 80% at most, and the clumping rates generally exceeded 20%.

[0151] This is because the embodiments utilize a xanthan gum-sodium caseinate-sodium pyrophosphate composite system to regulate the starch water absorption rate, matching it with the water absorption characteristics of quinoa fiber. Xanthan gum slows down starch water absorption, while sodium pyrophosphate breaks down starch agglomerates, preventing rapid starch gelatinization and the formation of a gel film. Simultaneously, the porous framework of quinoa fiber preserved by the composite enzymatic hydrolysis provides anchoring and dispersion channels for starch and oil particles, fundamentally reducing clumping. In contrast, in Comparative Example 1 (unmodified starch) and Comparative Example 6 (conventional mixture), starch water absorption is uncontrolled, leading to rapid gelatinization and coating of quinoa sprout powder, directly resulting in low solubility and severe clumping.

[0152] 2. From the perspective of storage stability:

[0153] Oil oxidation: The acid value of Examples 1-5 after 6 months was ≤0.23mg / g, which was much lower than that of the comparative example (≥0.5mg / g). This is due to the synergistic encapsulation of oil by modified starch and gum arabic, combined with the antioxidant effect of tea polyphenols, which blocked the catalysis of unsaturated fatty acids by lipoxygenase remaining in quinoa; while in Comparative Example 2 (oil was only emulsified), due to the lack of encapsulation, the oil was directly exposed, and oxidation was accelerated.

[0154] Oil floating: The oil floating rate in the examples is ≤0.6%, while that in the comparative examples is generally over 9%. This is because the examples achieve the dual effect of "third modified starch coating + silica density adjustment": the density of the first modified starch-oil complex is close to that of the water phase, and the silica coated by the third modified starch further balances the system density and reduces stratification; the comparative example 5 (lacking silica) has a higher floating rate due to the large density difference.

[0155] Structural integrity: The crack rate of the embodiment was ≤1.5%, while that of Comparative Example 4 (lacking TG enzyme) reached 28.9%. This is because the TG enzyme in the embodiment formed a covalent cross-linked network with calcium chloride, which enhanced the toughness of the particles and reduced shrinkage cracks when combined with gradient drying; Comparative Example 4, lacking cross-linking, had a network that was prone to breakage during drying.

[0156] 4. In terms of flavor and high humidity stability:

[0157] Flavor: The grassy odor scores of Examples 3-5 reached 9.3-9.4 points, significantly higher than those of Examples 1-2 (7.4-7.6 points) and the comparative example (6.8-7.5 points). This is because the added glucose oxidase and horseradish peroxidase decompose the quinoa-specific quinoa aldehyde (the source of the grassy odor), and β-cyclodextrin further encapsulates the residual odor, achieving dual deodorization through oxidation and encapsulation.

[0158] High humidity stability: The high humidity aggregation rate in Examples 4-5 was only 3.5-4.1%, far lower than the 9.0% in Example 1. This is due to the use of chitosan-third modified starch composite coating—chitosan and third modified starch are covalently cross-linked, and gum arabic enhances the cohesive force of the coating layer, preventing silica aggregation under high humidity and maintaining system stability.

[0159] In summary, this invention fundamentally solves the problems of clumping, oxidation, layering, and structural instability when quinoa sprouts are combined with high-starch and high-oil compounds by constructing a three-dimensional system of "quinoa dietary fiber skeleton / modified starch / first modified starch-oil complex". Experimental data proves that each key process step (such as starch modification, oil coating, and cross-linking network construction) is indispensable and together achieves a breakthrough improvement in product performance.

Claims

1. A processing technology for a ready-to-eat quinoa sprout pre-prepared food, characterized in that, Includes the following steps: S1. Raw material pretreatment: S11. Quinoa sprouts are washed, blanched, cooled, enzymatically hydrolyzed, freeze-dried, and pulverized to 100-200 mesh to obtain quinoa sprout powder. The parameters for the enzymatic hydrolysis step are as follows: a composite enzymatic hydrolysis system of 0.4-0.6 wt% cellulase and 0.2-0.3 wt% xylanase is used, with a mass ratio of 1:1-2; the enzymatic hydrolysis temperature is 40-50℃; and the time is 10-20 min. Before enzymatic hydrolysis, a fiber hardness pre-test was performed: the hardness value of quinoa sprouts was measured using a texture analyzer. If the hardness was >40N, the enzymatic hydrolysis time was 10-15 minutes; if the hardness was <30N, the enzymatic hydrolysis time was 18-20 minutes. Take a starch-containing food with a starch content of 60-85%, add plant antioxidant extract and pregelatinize it. Then add a basic colloid formed by xanthan gum and sodium caseinate to the pregelatinized starch, and slowly add sodium pyrophosphate solution. After stirring thoroughly, adjust the pH of the system to 6.5-7.0 with citric acid. After mixing thoroughly, pulverize to 100-200 mesh to obtain modified starch. The modified starch is divided into three parts: first modified starch, second modified starch, and third modified starch. S12. First, mix the oil-containing powder with an unsaturated fatty acid content of ≤60% with an emulsifier and a natural antioxidant. Then, emulsify it under high speed and high pressure and homogenize it to obtain an emulsion. Then, add the first modified starch, gum arabic and octenyl succinate starch ester to the emulsion. After mixing thoroughly, the first modified starch-oil complex is obtained. S2. Raw material mixing: First, quinoa sprout powder and second modified starch are thoroughly mixed to obtain a first mixture; then calcium chloride and transglutaminase are added to the first mixture, and after thorough mixing, the first modified starch-oil complex, lysophosphatidylcholine, and food-grade silica coated with third modified starch are added, and after thorough stirring, a second mixture is obtained. S3. Granulation and curing: Trehalose and a humectant were added to the second mixture, and after being fully dispersed, the mixture was granulated, followed by microwave treatment and gradient drying to obtain a pre-prepared food.

2. The processing technology for a pre-prepared quinoa sprout and malt food product according to claim 1, characterized in that, In step S2, the food-grade silica coated with the third modified starch is replaced with food-grade silica coated with a composite solution of chitosan and the third modified starch; the mass ratio between the chitosan and the third modified starch is (2-5):(7-10).

3. The processing technology for a pre-prepared quinoa sprout and stalk food for instant consumption according to claim 2, characterized in that, 0.4-7 wt% gum arabic is added to the chitosan-third modified starch composite solution; food-grade silica coated with chitosan and third modified starch composite solution is mixed with 0.08-0.12 wt% maltodextrin.

4. The processing technology for a pre-prepared quinoa sprout and malt food according to claim 1, characterized in that, In step S3, 0.08-0.12 wt% magnesium stearate is added to the humectant.

5. The processing technology for a pre-prepared quinoa sprout and stalk food for instant consumption according to claim 1, characterized in that, In step S12, gum arabic is replaced with a mixture of gum arabic and pectin, with a mass ratio of 2-5:1; 0.03-0.06 wt% sodium citrate is added to the gum arabic and pectin mixture.

6. The processing technology for a pre-prepared quinoa sprout and stalk food for instant consumption according to claim 1, characterized in that, In step S3, the gradient drying steps are as follows: first, dry at 25-35℃ for 1-1.5 h, then raise the temperature to 38-42℃ for 1-1.5 h, and finally raise the temperature to 44-46℃ for 1-1.5 h.

7. The processing technology for a pre-prepared quinoa sprout and stalk food for instant consumption according to claim 1, characterized in that, In the S11 complex enzymatic hydrolysis system, add 0.015-0.25 wt% glucose oxidase and 0.08-0.12 wt% horseradish peroxidase; When S11 xanthan gum and sodium caseinate form a basic colloid, add 0.2-0.5 wt% β-cyclodextrin.

8. The processing technology for a pre-prepared quinoa sprout and stalk food for instant consumption according to claim 1, characterized in that, The mass ratio of the quinoa sprout powder, starchy ingredients, and oily powder is (45-60):(20-30):(15-25).

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