A starch-based porous, crunchy, nutritious snack food and method for making same

Abstract

The application discloses a starch-based porous, crisp and nutritious leisure food and a preparation method thereof. The starch food is added into sterilized fresh milk, broken, mixed with well-foamed light cream and egg white after being cooked and gelatinized, and then edible yeast is added after cooling; then, the mixture is formed after being molded, fermented, rapidly frozen, pre-frozen and freeze-dried, and the finished product can be coated with chocolate, edible gel and butter to form an outer coating. The starch-based porous, crisp and nutritious leisure food prepared by the application has a pleasant aroma, a crisp taste, a clear level, is easy to digest and balanced in nutrition, and no chemical preservative, artificial pigment or other harmful substances are added in the preparation process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of starch food processing, and relates to a green, easily digestible and nutritious pure natural leisure food prepared by using molecular cooking technology and colloid technology. BACKGROUND

[0002] With the improvement of residents' consumption level, leisure food has become a new target in people's daily food consumption. According to statistics, the compound growth rate of the leisure food industry in the past ten years was as high as 12.29% per year. With the network interconnection and live broadcast of goods, the sales volume of a certain kind of leisure food can increase rapidly in a short time, bringing huge instantaneous profits to producers. Driven by changes in consumption habits and consumption upgrading, the consumer group has more requirements for leisure food, and on the basis of deliciousness, more attention is paid to health, nutrition and naturalness.

[0003] Starch food is the main source of human energy, including cereals (rice, millet, glutinous rice, etc.), tubers (potatoes, sweet potatoes, etc.), nuts (chestnuts, peanuts, etc.), beans (mung beans, soybeans, etc.), etc. Leisure food processed from starch food (i.e. starch-based leisure food) is deeply loved by consumers of all ages, but it usually causes nutritional and health problems. For example, potato chips and pastries use a large amount of sugar, fat, salt and additives and adopt the process of frying or baking, which can lead to excessive intake of calories and additives; rice cakes and bread sticks and low-processed cooked chestnut kernels can cause recrystallization of starch during cooling and storage, resulting in indigestible resistant starch, which affects the taste and easily causes indigestion.

[0004] In order to solve the problems of outdated production mode, insufficient processing capacity and easy nutritional and digestive burden of starch-based leisure food, it is necessary to develop high-value, healthy products and new processing technology. Heating starch in water will make its molecules swell and disperse, form a huge network structure and increase the viscosity of the solution (this process is called gelatinization), but the gelatinized starch will re-aggregate under conditions such as cooling (this process is called aging), and the aging process will produce aged starch (i.e. RS3). Therefore, Chinese patent CN105725151A uses cooking, beating, enzymatic hydrolysis and freeze-drying to reduce the starch content of chestnut kernels, but the product obtained is still single in nutritional ingredient source, and due to the high degree of starch degradation, it is not easy to be shaped after being mixed with other raw materials; Chinese patent CN113575828A adds saturated fatty acids during high-temperature gelatinization to achieve the effect of resisting chestnut starch aging, but the starch modified by easily allergenic ingredients such as myristic acid and lauric acid has safety hazards when used in food manufacturing. SUMMARY

[0005] The present application aims to provide a starch-based porous, crisp, nutritious snack food and a preparation method thereof. The starch-based snack food prepared by the present application can use different types and specifications (size, raw or cooked) of starch-based food as raw materials, and has the characteristics of crisp taste, distinct layers, easy digestion, balanced nutrition, no harmful additives, and convenient molding.

[0006] To achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] A starch-based nutritious snack food, which comprises a porous crisp composite gel embryo, and the porous crisp composite gel embryo is prepared by using the following raw materials in percentage by weight and sequentially undergoing gelatinization, sol adjustment, molding, fermentation foaming, low-temperature (≤-60℃) solidification and dehydration: 30%-39% of starch-based food, 40%-49% of gelatinization dispersant, 15%-20% of protein-based gel stabilizer, 5%-10% of lipid-based gel stabilizer, and 0.45%-1% of foaming agent.

[0008] Preferably, the gelatinization dispersant is sterilized milk (for example, sterilized fresh milk).

[0009] Preferably, the protein-based gel stabilizer is egg white solution (protein content of 10%-15%).

[0010] Preferably, the lipid-based gel stabilizer is whipping cream (fat content of 30%-40%).

[0011] Preferably, the foaming agent comprises edible yeast, and the amount (only edible yeast) is 1.5%-2.5% of the weight of the starch-based food.

[0012] Preferably, the starch-based food is a food rich in starch-based carbohydrates, including but not limited to one or more of the following: cereals (rice, millet, waxy rice, etc.), tubers (potatoes, sweet potatoes, etc.), nuts (chestnuts, peanuts, etc.), beans (green beans, soybeans, etc.), and specifications include one or more of raw products (for example, raw chestnut kernels, rice, raw chestnut powder of different thicknesses, wheat flour) or cooked products (for example, cooked chestnut kernels, cooked rice, cooked potatoes, cooked chestnut powder of different thicknesses). The raw products need longer cooking time than the cooked products in gelatinization.

[0013] Preferably, the porous, crispified, composite gel-type embryo is prepared by gelatinizing 9-10 parts of starch-based food-milk slurry in the presence of 1.5-2 parts of foamed egg albumen solution and 1-1.5 parts of foamed light cream, mixing with edible yeast, molding, and fermenting, and then subjecting the formed starch-based food-milk gel to quick freezing, pre-freezing, and freeze-drying, wherein the starch-based food-milk slurry is prepared by gelatinizing 3-4 parts of starch-based food in 5-6 parts of sterilized milk.

[0014] Preferably, the snack food further comprises an outer coating layer wrapped around the porous, crispified, composite gel-type embryo.

[0015] Preferably, the outer coating layer is prepared by applying chocolate, cream, or edible gel on the surface of the porous, crispified, composite gel-type embryo, wherein the edible gel is a combination of one or more of carrageenan, pectin, agar, gelatin, and the like (i.e., composite gel); and the weight percentage of the outer coating layer in the snack food is 20%-30%.

[0016] The above-mentioned method for preparing the starch-based nutritional snack food comprises the following steps:

[0017] After gelatinizing the starch-based food in the presence of a gelatinization dispersant, the starch-based food is mixed with a protein-based gel stabilizer and a lipid-based gel stabilizer, cooled, mixed with a foaming agent, and then molded, followed by fermentation foaming and low-temperature (≤-60°C) solidification dehydration, to obtain a porous, crispified, composite gel-type embryo.

[0018] Preferably, the method comprises the following steps:

[0019] 1) crushing

[0020] The starch-based food is mixed with sterilized milk at a mass ratio of (3-4):(5-6), crushed, and mixed with the sterilized milk to obtain a suspension; wherein the suspensions obtained after crushing and mixing with sterilized milk are not significantly different for different starch-based foods.

[0021] 2) gelatinization

[0022] The suspension obtained in step 1 is boiled at 90-100°C under stirring for 40-60 minutes to obtain a starch-based food-milk slurry.

[0023] 3) mixing, molding, and fermentation

[0024] Mix the starch-based food paste obtained in step 2 with the foamed egg white protein solution and the foamed light cream. After cooling to 35-40℃, mix with edible yeast to obtain starch-based food latex. Add the starch-based food latex to a mold and ferment at 35-40℃ for 20-30 minutes. The mass ratio of starch-based food paste to foamed egg white protein solution to foamed light cream is (9-10):(1.5-2):(1-1.5).

[0025] 4) Shaping

[0026] After step 3, the contents of the mold are subjected to quick-freezing and pre-freezing in sequence to obtain a solid block of glue.

[0027] 5) Freeze-drying

[0028] The gel block obtained in step 4 is subjected to vacuum freeze-drying to obtain the freeze-dried gel block product, namely, a porous brittle composite gel embryo.

[0029] Preferably, in step 3, the edible yeast is prepared into a solution and then mixed. The solution is prepared by dispersing the edible yeast in water at 30-35°C, wherein the mass ratio of edible yeast to water is 1:1.5-1:2.

[0030] Preferably, in step 4, the conditions for quick freezing and shaping are: liquid nitrogen treatment for 30-60 seconds, with better shaping effect (e.g., no deformation or shrinkage); the pre-freezing temperature is -60℃ to -80℃, and the time is more than 12 hours.

[0031] Preferably, in step 5, the vacuum freeze-drying temperature is -70℃ to -80℃, the pressure is 0 to 10 Pa, and the time is more than 24 hours.

[0032] Preferably, the preparation method further includes the following step: after the freeze-dried rubber block is demolded, an outer coating is applied.

[0033] Preferably, the outer coating is applied to the surface of the freeze-dried rubber block using the following different methods, depending on the composition of the outer coating:

[0034] Chocolate coating: The freeze-dried plastic block is immersed in melted chocolate and then cooled, so that the chocolate adhering to the surface of the freeze-dried plastic block solidifies.

[0035] Cream coating: Apply cream to the freeze-dried gel block;

[0036] Edible gel outer coating: Dissolve the edible gel in hot water and apply it to the freeze-dried gel block. Then, cool the edible gel adhering to the surface of the freeze-dried gel block to solidify.

[0037] Preferably, the preparation of the foamed egg white protein solution specifically includes the following steps: separating the egg white and yolk of a sterile egg, whipping the egg white until dense bubbles are produced (when the bubbles continuously increase to a stable state after the start of whipping), which is regarded as the whipping endpoint, thus obtaining the foamed egg white protein solution.

[0038] Preferably, the preparation of the foamed whipped cream specifically includes the following steps: whipping the whipped cream until dense bubbles are produced (when the bubbles are produced to the maximum and stabilize after the start of whipping), which is considered the whipping endpoint, thus obtaining the foamed whipped cream. Whipping should be stopped after reaching the whipping endpoint, otherwise the foam will be deflated or even the structure of the whipped cream will be destroyed.

[0039] The beneficial effects of this invention are reflected in:

[0040] This invention relates to a starch-based nutritional snack food that incorporates gelatinizing dispersants, protein gel stabilizers, lipid gel stabilizers, and foaming agents into its raw material composition. After gelatinization, the starchy food can be shaped using a gel drying and solidification method (not a high-temperature frying method, thus avoiding the introduction of oil residue). This results in a finished product (a porous, crispy composite gel embryo) with a crispy texture similar to puffed snacks. This not only reduces fat intake but also results in a low content of retrograded starch (the proteins, fats, and air bubbles generated by the foaming agent in the aforementioned raw material components can hinder the approach and crystallization of starch molecules, i.e., resist starch retrogradation) and easy digestibility. Furthermore, this starch-based nutritional snack food does not contain chemical preservatives, artificial colors, or other harmful substances (such as toxic byproducts generated during high-temperature processing).

[0041] Furthermore, in this invention, sterilized milk, egg white protein solution, light cream, and edible yeast are used to assist starch in constructing a network interpenetrating gel. This not only solves the problem of starch being prone to aging, but also effectively encapsulates and protects the nutrients and flavor components in the gel, resulting in a nutritionally balanced product with a harmonious and pleasant aroma.

[0042] Furthermore, the present invention can utilize foamed egg white protein solution and light cream, as well as bubbles generated by fermentation (decomposition of glucose) of edible yeast to construct a unique porous structure in the finished product, combined with an outer coating, so that starch-based nutritional snack foods have a diverse and multi-layered taste.

[0043] Furthermore, by rapidly freezing, pre-freezing, and freeze-drying the product after molding and fermentation, this invention can give the finished product a unique appearance and achieve the purpose of freely shaping the finished product. At the same time, it can also reduce the production of aged starch (by rapidly cooling and solidifying the water in the starchy food-latex, the starch molecules are fixed before they have time to orient and move). Attached Figure Description

[0044] Figure 1 Macroscopic morphology images of freeze-dried chestnut gel embryos from different treatment groups.

[0045] Figure 2 Microscopic morphology images of freeze-dried chestnut gel embryos from different treatment groups.

[0046] Figure 3 Macroscopic and microscopic morphological images of freeze-dried rice gel embryos from different treatment groups.

[0047] Figure 4 Macroscopic and microscopic morphological images of freeze-dried potato gel embryos from different treatment groups.

[0048] Figure 5 The UV-Vis full-band scanning spectra of freeze-dried chestnut gel embryos from different treatment groups.

[0049] Figure 6 Infrared absorption spectra of freeze-dried chestnut gel embryos from different treatment groups.

[0050] Figure 7 X-ray diffraction patterns of freeze-dried chestnut gel embryos, rice gel embryos, and potato gel embryos after different treatment groups.

[0051] Figure 8 Figure 1 shows the resistant starch content of freeze-dried chestnut gel embryos, rice gel embryos, and potato gel embryos after different treatment groups.

[0052] Figure 9 This is a flowchart illustrating the process flow of the starch-based porous, crispy, and nutritious snack food described in the embodiments.

[0053] Figure 10 A schematic diagram of the molds used in fermentation, liquid nitrogen quick-freezing, pre-freezing, and freeze-drying.

[0054] Figure 11 This is a schematic diagram of the freeze-dried product.

[0055] Figure 12 This is a schematic diagram of the freeze-dried product and the outer coating of the chocolate. Detailed Implementation

[0056] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The embodiments described are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0057] (I) Process and Formulation Optimization

[0058] To enhance the processing capabilities of starchy foods and overcome the shortcomings of traditional starch-based snack foods, such as insufficient nutritional balance, lack of variety, and limited product range, this invention combines molecular gastronomy and colloid technologies. By utilizing non-thermal processing, it maximizes the preservation of various effective nutrients and flavors in starchy foods. Simultaneously, through optimization and comparative analysis of key formulations and processes, the final product (such as the starch-based porous, crispy, and nutritious snack food prepared in the examples below) possesses a unique porous appearance, balanced nutrition, easy digestibility, crispy texture, and zero additives.

[0059] (1) Preparation of a control group of starchy foods (chestnuts, rice, or potatoes)

[0060] Take shelled cooked chestnut kernels, cooked rice, or peeled cooked potatoes, add 1.25 times their weight of water, then blend until smooth and free of lumps, to obtain a homogeneous suspension. Heat the suspension and maintain it at 95°C for 45 minutes to obtain a starch-water paste. Cool the starch-water paste to 35°C, place it in a mold, and maintain the temperature at 35°C for 30 minutes. Pre-freeze the contents of the mold (at -80°C for 12 hours) and freeze-dry (at -80°C and 10 Pa for 24 hours).

[0061] (2) Preparation of a formula optimization group for starchy foods (chestnuts, rice, or potatoes)

[0062] Take shelled cooked chestnut kernels, cooked rice, or peeled cooked potatoes, add 1.25 times their weight of sterilized fresh milk, then blend until a homogeneous suspension free of lumps is obtained. Heat the suspension and maintain it at 95°C for 45 minutes to obtain a starch-based food paste. Mix the starch-based food paste with unfrozen egg white solution and unfrozen light cream (35% fat content) at a mass ratio of 9:2:1. Cool to 35°C, then place it in a mold and maintain the temperature at 35°C for 30 minutes. Pre-freeze the contents of the mold (at -80°C for 12 hours) and freeze-dry (at -80°C and 10 Pa for 24 hours).

[0063] (3) Preparation of starchy foods (chestnuts, rice, or potatoes) by the process-formulation optimization group

[0064] Take shelled cooked chestnut kernels, cooked rice, or peeled cooked potatoes, add 1.25 times their weight of sterilized fresh milk, then blend until a homogeneous suspension free of lumps is obtained. Heat the suspension and maintain it at 95°C for 45 minutes to obtain a starch-based food paste. Mix the starch-based food paste with whipped egg white solution and whipped cream (35% fat content) in a 9:2:1 mass ratio. Cool to 35°C, then mix in edible yeast solution (yeast to water mass ratio of 1:2, yeast mass being 2% of the total starch-based food mass). Place the mixture in a mold and maintain a constant temperature of 35°C for 30 minutes. Quickly freeze the mold and its contents in liquid nitrogen for 30 seconds to set. Then, pre-freeze the contents of the mold (at -80°C for 12 hours) and freeze-dry (at -80°C, 10 Pa for 24 hours).

[0065] (4) Macroscopic morphological observation

[0066] like Figure 1 , Figure 3 , Figure 4 As shown, the appearance and internal structure of the gel-shaped embryos obtained from the three different treatment groups of the starchy foods exhibited significant differences. The control group and the optimized formula group showed smooth surfaces, dense and compact cross-sections, and uneven component distribution; the optimized formula group produced a porous structure with uniform component distribution. This indicates that the egg white protein solution and whipping cream process, the fermentation process of edible yeast, and the liquid nitrogen rapid cooling process contribute to the formation of the crumbly and porous structure of the gel-shaped embryo and the stable dispersion of different components.

[0067] (5) Microscopic morphological observation

[0068] The gel-shaped embryos obtained from the three different treatment groups of the above starchy foods were ground into powder, and an appropriate amount was fixed on conductive adhesive. Gold was sputtered using an E-1045 sputtering machine (HITACHI, Tokyo, Japan), and observed under an accelerating voltage of 10kV using an S-3400N scanning electron microscope (HITACHI, Tokyo, Japan) at a magnification of 1000x.

[0069] The results are as follows Figure 2 , Figure 3 , Figure 4As shown, the internal microstructure of the gel-shaped embryos obtained from different treatment groups exhibited significant differences. Specifically, the chestnut and potato control groups produced large, blocky crystalline structures, while the rice control group produced a starch crystalline network with a rough surface. The optimized formulation group produced crystal structures with smaller sizes and less surface roughness. The optimized formulation group produced the smallest structures, transforming from the flat structure of the optimized formulation group into a three-dimensional porous structure with the smallest surface roughness. This indicates that lipids and proteins encapsulate starch molecules, hindering the formation of large starch retrogradation crystals. Simultaneously, the bubbles generated during whipping and fermentation construct unique configurations, also hindering starch retrogradation crystallization and the proximity of various components. Furthermore, rapid cooling quickly fixes moisture, preventing starch molecules from orienting and moving, thus fixing them in place.

[0070] (6) Full-band scanning of ultraviolet-visible absorption spectroscopy

[0071] The chestnut gel-type embryos obtained from the three different treatment groups were ground into powder, and a turbid solution was prepared by shaking thoroughly with water as a dispersant at a concentration of 10 mg / mL. The samples were then scanned across the entire wavelength range of 200-800 nm using a UV-1800 UV-Vis spectrophotometer (Shimadzu Japan).

[0072] The results are as follows Figure 5 As shown, the absorption intensity at 260nm was ranked as follows: Process-Formulation Optimization Group > Formulation Optimization Group > Chestnut Control Group, indicating that the Process-Formulation Optimization Group and the Formulation Optimization Group contained more protein. Meanwhile, the Process-Formulation Optimization Group had the highest absorption peak intensity across the entire wavelength range, indicating good water resolubility and easier digestion.

[0073] (7) Fourier transform infrared spectroscopy analysis

[0074] The chestnut gel-type embryos obtained from the three different treatment groups were ground into powder. Using potassium bromide as a dispersant, samples were prepared by pressing into tablets at a mass ratio of sample:potassium bromide = 1:200. The samples were then recorded using an INVENIO S Fourier transform infrared spectrometer (Burcker, Germany), with a measurement range of 4000-4000 cm⁻¹. -1 The resolution is 4cm. -1 The characteristic vibrational peak of -OH (1027 cm⁻¹) -1 The three sets of data were normalized.

[0075] The results are as follows Figure 6 As shown, the chestnut control group showed peak values ​​at CH stretching vibrations (2921, 2850 cm⁻¹). -1 The stretching vibration peak of C=H (1638 cm⁻¹) -1 ), aldehyde C=O stretching vibration peak (1745 cm⁻¹) -1The values ​​were smaller than those of the formulation optimization group and the process-formulation optimization group, indicating that the formulation optimization group and the process-formulation optimization group contained more lipids and proteins. Furthermore, under the influence of the egg white protein solution, whipped cream, and bubbles generated during fermentation, the lipids and proteins in the process-formulation optimization group were more exposed. This verifies that lipids and proteins in the microstructure can encapsulate starch molecules, affecting their microscopic surface smoothness and hindering the components from approaching each other and crystallizing.

[0076] (8) Crystallinity analysis

[0077] The gel-shaped embryos obtained from the three different treatment groups of the above starchy foods were scanned at room temperature using a D8 Advance powder X-ray diffractometer (Brucker, Germany) with angles of 10-40°, 2θ accuracy of 0.02, and wavelength of 1.54 × 10⁻⁶ m. -10 The X-ray tube voltage is 40kV and the current is 80mA.

[0078] The results are as follows Figure 7 As shown, 16-22° is the characteristic peak of starch crystallization. Calculating the relative crystallinity using the relative peak area reveals that the order of starch crystallinity in the gel-type embryos of different treatment groups is: control group > formulation optimization group > process-formulation optimization group. This indicates that the order of aged starch content is: control group > formulation optimization group > process-formulation optimization group, proving that both formulation and process optimization can inhibit the formation of aged starch. Furthermore, a new crystallization peak appeared in the chestnut process-formulation optimization group at 11-14°, which, based on the microscopic morphology, is inferred to be a complex crystal of lipids, proteins, and starch. This peak was not observed in the formulation optimization group, indicating that the whipping process of egg white protein solution and light cream, as well as the fermentation process of edible yeast, affected the recrystallization of molecules, contributing to the reconstruction of the sample's microstructure. This peak was not observed in the rice and potato groups, possibly because different foods contain different starch molecules, indicating that the formation of complex crystals is related to the starch structure and properties. This corresponds to the different morphologies observed in the scanning electron microscope and the infrared results.

[0079] (9) Texture-chewability analysis

[0080] The gel-shaped embryos obtained from the three different treatment groups of the above starchy foods were divided into 1cm sections. 3 Small pieces were tested using a total texture analysis (TPA) puncture test to determine their hardness, elasticity, and chewiness. The test was conducted using an analyzer with a stable microsystem (TA.XT.Plus, UK), a P / 2N probe, a test speed of 1.0 mm / s, a trigger force of 5 g, and a test interval of 5 s.

[0081] Table 1. Texture-chewability analysis data

[0082]

[0083] Note: Different superscript letters indicate significant differences between groups, while the same superscript letter indicates no significant difference.

[0084] The results are shown in Table 1. Compared with the control group, the optimized formulation group and the process-formulation optimization group significantly reduced hardness, adhesiveness, and chewiness. Furthermore, the porous structure generated in the process-formulation optimization group added crispness to the product, indicating that the dual optimization of formulation and process resulted in better palatability and a richer chewiness.

[0085] (10) Analysis of resistant starch content

[0086] The gel-shaped embryos obtained from the three different treatment groups of the above starchy foods were ground into powder. 100 mg was accurately weighed and added to 6 mL of water, followed by 4 mL of α-amylase solution (enzyme concentration 10 U / mL). The mixture was then incubated at 37°C with shaking for 16 hours. After the reaction, the mixture was centrifuged at 8000 rpm for 10 min. 25 μL of the supernatant was collected and the glucose concentration (c1) was determined using a biosensor analyzer (Sieman Technology Shenzhen). The supernatant was then discarded, and the precipitate was washed twice with 50% ethanol and dried. 2 mL of 2 mol / L KOH solution was added to a centrifuge tube, and the mixture was incubated in an ice-water bath for 20 min. Then, 8 mL of 1.2 mol / L, pH 3.8 sodium acetate buffer was added, followed by 0.1 mL of 3300 U / mL α-amylase solution. The mixture was then incubated at 60°C with shaking for 1 h. After the reaction was completed, the mixture was centrifuged at 8000 r / min for 10 min. 25 μL of the supernatant was taken and the glucose concentration was measured using a biosensor analyzer (Sieman Technology Shenzhen) to obtain concentration c2. The resistant starch content was calculated using the following formula:

[0087] C resistant starch = c2 / (c1+c2)%

[0088] The results are as follows Figure 8 As shown, the resistant starch content in the chestnut control group and the optimized formula group was around 55%, while the resistant starch content in the optimized process-formula group was below 25%, significantly lower than that in the chestnut control group and the optimized formula group. The resistant starch content in the rice control group was around 18%, while the optimized formula group and the optimized process-formula group significantly reduced the resistant starch content to around 15% and 7%, respectively. The resistant starch content in the potato control group and the optimized formula group was around 34% and 30%, respectively, while the resistant starch content in the optimized process-formula group was around 15%, significantly lower than that in the potato control group and the optimized formula group. These results correspond to the X-ray diffraction results, indicating that under optimized process and formula, the introduced lipids, proteins, and air bubbles hinder the approach and binding of starch molecules during processing, reducing starch retrogradation and thus making the freeze-dried product easier to digest.

[0089] (II) Examples of preparing starch-based porous, crispy, and nutritious snack foods using optimized processes and formulations

[0090] Example 1 (see Figure 9 )

[0091] 1.1 Crushing: Take shelled cooked chestnut kernels, add 1.25 times the weight of sterilized fresh milk (i.e., sterilized raw milk), and then use a JYL-C23 juicer to crush and mix thoroughly at 16000 rpm for 60 seconds at room temperature to obtain a uniform suspension without small pieces of chestnut kernels.

[0092] 1.2 Gelatinization: The suspension obtained in step 1.1 is heated and kept at 95°C for cooking, with constant stirring. After 45 minutes, heating is stopped. At this time, the suspension is slightly concentrated, with a uniform texture, increased viscosity, and darker color, resulting in a chestnut-paste liquid containing fully gelatinized chestnut starch.

[0093] 1.3 Preparation: Prepare 0.5 times the weight of the chestnut kernels used in step 1.1, sterile egg whites, and 0.25 times the weight of commercial light cream (35% fat content). Whisk them thoroughly with an electric mixer until foamy, then mix them evenly with the chestnut-milk paste (mix gently to avoid defoaming). After cooling to 35℃, add 0.02 times the weight of the chestnut kernels used in step 1.1, and before adding, fully disperse the yeast with an appropriate amount of water (35℃) (the mass ratio of yeast to water is 1:2). Mix gently to avoid defoaming to obtain chestnut-milk sol (raw material ratio: 33.1% by weight of chestnut kernels, 41.4% by weight of sterilized fresh milk, 16.5% by weight of whipped egg whites, 8.3% by weight of whipped light cream, and 0.7% by weight of yeast).

[0094] 1.4 Molding and Fermentation: Afterwards, pour the chestnut-latex mixture into molds of a specific size and shape (see...). Figure 10 Then place the mold in a 35℃ constant temperature box for 30 minutes to ferment and obtain chestnut-latex.

[0095] 1.5 Quick-freezing and shaping: Place the mold and fermented contents (i.e. chestnut-latex) from step 1.4 into liquid nitrogen and quick-freeze for 30 seconds to set the shape. Then place it in a -80℃ freezer and pre-freeze at normal pressure for 12 hours to obtain a solid gel block.

[0096] 1.6 Freeze-drying: The gel blocks were placed in a freeze dryer and freeze-dried at -80℃ and 10Pa for 24 hours to obtain dried gel blocks with free water removed (i.e., porous brittle composite chestnut gel-type embryos, see [link]). Figure 11 );

[0097] 1.7 Coating: Melt the chocolate using a double boiler. Demold the dried gel block obtained in step 1.6. Submerge the outer surface of the freeze-dried product, partially or completely, in the melted chocolate. Remove the product and allow it to cool and set. This yields a starch-based porous, crisp, and nutritious snack food (see chocolate coating instructions). Figure 12 (Approximately 20% by weight).

[0098] Example 2 (see Figure 9 )

[0099] 1.1 Crushing: Take shelled fresh chestnut kernels, add 1.5 times the weight of sterilized fresh milk, and then use a JYL-C23 juicer to crush and mix thoroughly at 16000 rpm for 60 seconds at room temperature to obtain a uniform suspension without small pieces of chestnut kernels.

[0100] 1.2 Gelatinization: The suspension obtained in step 1.1 is heated and kept at 100°C for cooking, with constant stirring. After 60 minutes, heating is stopped. At this time, the suspension is slightly concentrated, with a uniform texture, increased viscosity, and darker color, resulting in a chestnut-paste liquid containing fully gelatinized chestnut starch.

[0101] 1.3 Preparation: Prepare 0.5 times the weight of the chestnut kernels used in step 1.1, sterile egg whites, and 0.25 times the weight of commercial light cream (35% fat content). Whip them thoroughly with an electric mixer until foamy, then mix them evenly with the chestnut-liquid mixture (mix gently to avoid defoaming). After cooling to 35°C, add 0.02 times the weight of the chestnut kernels used in step 1.1, and before adding, fully disperse the yeast with an appropriate amount of water (35°C) (the mass ratio of yeast to water is 1:2). Mix gently to avoid defoaming to obtain chestnut-liquid sol (raw material ratio: 30.6% by weight of chestnut kernels, 45.9% by weight of sterilized fresh milk, 15.2% by weight of whipped egg whites, 7.7% by weight of whipped light cream, and 0.6% by weight of yeast).

[0102] 1.4 Molding and Fermentation: Afterwards, pour the chestnut-latex mixture into molds of a specific size and shape (see...). Figure 10 Then place the mold in a 35℃ constant temperature box for 30 minutes to ferment and obtain chestnut-latex.

[0103] 1.5 Quick-freezing and shaping: Place the mold and fermented contents (i.e. chestnut-latex) from step 1.4 into liquid nitrogen and quick-freeze for 30 seconds to set the shape. Then place it in a -80℃ freezer and pre-freeze at normal pressure for 12 hours to obtain a solid gel block.

[0104] 1.6 Freeze-drying: The gel blocks were placed in a freeze dryer and freeze-dried at -80℃ and 10Pa for 24 hours to obtain dried gel blocks with free water removed (i.e., porous brittle composite chestnut gel-type embryos, see [link]).Figure 11 );

[0105] 1.7 Coating: After demolding the dried gel block obtained in step 1.6, apply butter directly to its surface to obtain a starch-based porous, crispy, and nutritious snack food (butter coating, approximately 20% by weight).

[0106] (III) Process Formulation and Product Advantages

[0107] 1. Using starch-based foods and milk as gelling raw materials, the starch is gelatinized by low-heat cooking of milk. Proteins, fats, and air bubbles are introduced during the formulation and fermentation steps, interspersed in the long-chain structure of the starch, which prevents starch molecules from approaching and crystallizing, effectively reducing starch retrogradation. At the same time, it forms a stable interpenetrating hydrogel with the starch molecules and effectively locks in small molecules of nutrients and flavor such as amino acids, polyphenols, and fatty acids.

[0108] 2. The bubbles in the whipped cream and egg whites during the mixing process, as well as the bubbles produced by the yeast during the fermentation process, create a unique porous structure, giving the snack food a unique appearance and a crispy, multi-layered texture.

[0109] 3. The quick-freezing and shaping step uses liquid nitrogen to rapidly fix the shape and molecular structure of the finished product, reducing starch retrogradation;

[0110] 4. Moisture is removed by vacuum freeze-drying process, creating a unique internal and external structure of the freeze-dried product. The non-fried high-temperature processing method brings a crispy texture without introducing oil residue or toxic byproducts of high-temperature processing.

[0111] 5. Protein and fat are added to starchy food ingredients that are mainly composed of carbohydrates to balance the nutritional ratio of starch-based snack foods, without adding preservatives, flavor enhancers, artificial chemical additives, etc.

[0112] 6. The appearance and outer coating of the finished product can be customized according to commercial needs and consumption scenarios. For example, chocolate, edible gel, or cream can be selectively wrapped on the outer surface of the finished product to form an outer coating.

[0113] 7. The processing does not have strict requirements on the appearance and quality of starchy food raw materials, which helps to reduce the waste of some raw materials with poor appearance but good quality; at the same time, the addition of air bubbles and the formation of a loose network structure can effectively control costs and improve enterprise efficiency.

Claims

1. A starch-based nutritional snack food, characterized in that: The leisure food comprises a porous crisp composite gel embryo, which is made of the following raw materials in percentage by weight: 30%-39% of starch food, 40%-49% of gelatinized dispersant, 15%-20% of protein gel stabilizer, 5%-10% of lipid gel stabilizer, and 0.45%-1% of foaming agent; The gelatinized dispersant is sterilized milk; The protein gel stabilizer is egg white solution; and the lipid gel stabilizer is light cream; The foaming agent comprises edible yeast; The porous crisp composite gel embryo is specifically prepared by mixing the starch food with the gelatinized dispersant after starch gelatinization, mixing the foamed egg white solution and the foamed light cream, mixing the foaming agent after cooling, and then performing fermentation foaming, liquid nitrogen quick freezing, pre-freezing, and freeze drying in sequence. The starch food is one or more of the following foods rich in starch-based carbohydrates: cereals, tubers, nuts, and beans.

2. The starch-based snack food of claim 1, wherein: The amount of the edible yeast is 1.5%-2.5% of the weight of the starch food.

3. The starch-based snack food of claim 1, wherein: The leisure food further comprises a chocolate, cream, or edible gel outer coating layer wrapped on the porous crisp composite gel embryo.

4. A process for the preparation of a starch-based nutritional snack food according to any one of claims 1 to 3, characterised in that: The preparation method comprises the following steps: 1) crushing The starch food and the sterilized milk are mixed in a mass ratio of (3-4):(5-6), and then the starch food is crushed to form a suspension with the sterilized milk; 2) gelatinization The suspension obtained in step 1) is boiled at 90-100 ℃ under stirring for 40-60 minutes to obtain a starch food-milk paste; 3) mixing, molding, and fermentation The starch food-milk paste obtained in step 2) is mixed with the foamed egg white solution and the foamed light cream, and then mixed with the edible yeast after cooling to 35-40 ℃ to obtain a starch food-milk sol, which is then added to a mold and fermented at 35-40 ℃ for 20-30 minutes; wherein the mass ratio of the starch food-milk paste, the foamed egg white solution, and the foamed light cream is (9-10):(1.5-2):(1-1.5); 4) shaping After step 3), the content of the mold is sequentially subjected to quick freezing and pre-freezing to obtain a solid gel block; 5) freeze drying The gel block obtained in step 4) is subjected to vacuum freeze drying to obtain a gel block freeze-dried product, i.e., a porous crisp composite gel embryo.

5. The method of preparing a starch-based snack food of claim 4, characterized in that: In step 3), the edible yeast is dispersed in water at 30-35 ℃ to form a solution, and then mixed, wherein the mass ratio of the edible yeast to water is 1:1.5-1:

2.

6. The method of preparing a starch-based snack food of claim 4, characterized in that: In step 4), the quick freezing is performed by treating with liquid nitrogen for 30-60 seconds.

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