Canna edulis ker cooked whole flour and preparation method thereof

Abstract

The invention provides cooked whole canna edulis ker powder and a preparation method thereof, and belongs to the technical field of food processing. The preparation method of the cooked whole canna edulis ker powder comprises the following steps: (1) slicing canna edulis ker, and soaking the sliced canna edulis ker in a composite color fixative solution to obtain color-protected canna edulis ker slices; (2) curing the canna edulis ker slices subjected to color protection treatment to obtain cooked canna edulis ker slices; (3) soaking the cooked canna edulis ker slices in the composite color fixative solution for cooling and color protection, drying and crushing to obtain cooked whole canna edulis ker powder; wherein the composite color fixative comprises vitamin C, sodium citrate and calcium ascorbate. The invention provides the preparation method of the cooked canna edulis ker whole flour, which can obviously inhibit browning and improve the quality of the whole flour, and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the field of food processing technology, and in particular to a cooked taro flour and its preparation method. Background Technology

[0002] Current technologies for preparing taro whole powder often employ simple color-protecting and drying processes, but these have significant drawbacks: taro tubers are prone to browning during steaming due to increased polyphenol oxidase (PPO) activity, leading to color deterioration (manifested as an increased total color difference ΔE value), affecting the sensory quality and functional indicators of the whole powder (such as increased iodine blue value and decreased rehydration ratio). Existing technologies use only one color-protecting agent (e.g., vitamin C alone), resulting in unstable color-protecting effects. Furthermore, the slice thickness, steaming time, and drying parameters are not optimized, leading to low drying efficiency, insufficient starch gelatinization, and a final product with a dark color, coarse texture, and difficulty in controlling the moisture content to ≤10%.

[0003] Therefore, in order to address the above-mentioned shortcomings, it is necessary to provide a method for preparing cooked taro flour that solves the browning problem through the combination of composite color-protecting agents and optimization of process parameters, and to improve the rehydration and functionality of cooked taro flour. Summary of the Invention

[0004] The purpose of this invention is to provide a whole powder of banana taro and its preparation method.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing cooked taro flour, comprising the following steps: (1) After slicing the taro, soak it in a compound color-protecting agent solution to obtain color-protected taro slices; (2) The banana taro slices that have undergone color protection treatment are cooked to obtain cooked banana taro slices; (3) Soak cooked taro slices in the composite color-protecting agent solution to cool and protect the color, dry and pulverize to obtain cooked taro powder; The composite color-protecting agent includes vitamin C, sodium citrate, and calcium ascorbate.

[0006] Preferably, the taro is washed and peeled before slicing in step (1); the thickness of the slices is 2~6mm.

[0007] Preferably, the composite color-protecting agent solution contains 0.3-0.5% by mass and volume of vitamin C, 0.5-0.9% by mass and volume of sodium citrate, and 0.3-0.5% by mass and volume of calcium ascorbate.

[0008] Preferably, the temperature of the color protection treatment in step (1) is 22~28℃ and the time is 10~20min.

[0009] Preferably, the cooking method in step (2) is steaming or boiling, and the steaming or boiling time is 4 to 11 minutes.

[0010] Preferably, the cooling and color protection temperature in step (3) is 22~28℃ and the time is 3~10min.

[0011] Preferably, the drying temperature in step (3) is 40~60℃ and the time is 12~24h.

[0012] Preferably, the pulverization in step (3) is pulverized to 80~100 mesh.

[0013] This invention provides a method for preparing cooked taro powder.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This invention significantly enhances the synergistic and stable color-protecting effect by employing a composite color-protecting agent with a specific ratio of vitamin C, sodium citrate, and calcium ascorbate. This composite color-protecting agent effectively inhibits the activity of polyphenol oxidase (PPO), fundamentally blocking the enzymatic browning reaction of taro chips during steaming. This invention effectively overcomes the instability of traditional single color-protecting agents, resulting in a significant reduction in the overall color difference of the final cooked taro powder, a fundamental improvement in appearance, and the avoidance of abnormally high iodine blue values ​​and decreased rehydration properties caused by browning, thus ensuring the product's excellent sensory quality and stable functional indicators.

[0015] This invention also optimizes key process steps such as slice thickness, pre-cooking color protection time, cooking time, cooling color protection time, and drying parameters, ensuring full gelatinization of starch granules and significantly improving drying efficiency, allowing the product moisture content to be stably controlled at a low level of ≤10%. This not only extends the product's shelf life but also significantly improves key quality indicators such as the final product's color, texture (avoiding a rough feel), and rehydration ratio, achieving stable and efficient production of high-quality taro flour.

[0016] Traditionally, it is believed that extending the cooking time can improve gelatinization, but this invention has found that a cooking time of ≤5 min can simultaneously ensure gelatinization and color, thus overcoming technical bias and producing unexpected results.

[0017] In summary, this invention provides a method for preparing cooked taro flour that can significantly inhibit browning and improve the quality of the flour, and has broad application prospects. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0019] Figure 1 Images show the dried state of taro slices and taro powder after treatment with different color-protecting agents in different sequences. In each treatment group, the upper part of the image shows the dried taro slices, and the lower part shows the taro powder. Figure 2 Images show the state of taro slices after steaming and drying, obtained by different color protection times before steaming, and the state of taro powder. In each treatment group, the upper part of the image shows the state of the dried taro slices, and the lower part shows the state of the taro powder. Figure 3 Images show the state of dried taro slices and taro powder obtained after different cooling and color-protecting times; the upper part of each treatment group's image shows the state of dried taro slices, and the lower part shows the state of taro powder. Figure 4 Images show the state of taro slices of different thicknesses after steaming and drying, as well as the state of taro powder. In each treatment group, the upper part of the image shows the state of the dried taro slices, and the lower part shows the state of the taro powder. Figure 5 Images showing the state of dried taro slices obtained after different steaming times (5~30min); Figure 6 Images showing the state of dried taro slices obtained after different steaming times (0~10 min); Figure 7 Images show the state of dried taro slices and taro powder obtained at different drying temperatures; in each treatment group, the upper part of the image shows the state of dried taro slices, and the lower part shows the state of taro powder. Detailed Implementation

[0020] This invention provides a method for preparing cooked taro flour, comprising the following steps: (1) After slicing the taro, soak it in a compound color-protecting agent solution to obtain color-protected taro slices; (2) The banana taro slices that have undergone color protection treatment are cooked to obtain cooked banana taro slices; (3) Soak cooked taro slices in the composite color-protecting agent solution to cool and protect the color, dry and pulverize to obtain cooked taro powder; The composite color-protecting agent includes vitamin C, sodium citrate, and calcium ascorbate.

[0021] In this invention, the banana taro is washed and peeled before slicing in step (1); the thickness of the slice is 2~6mm, preferably 3~5mm, and more preferably 4mm.

[0022] In this invention, the mass-volume percentage of vitamin C in the composite color-protecting agent solution is 0.3-0.5%, preferably 0.35-0.45%, more preferably 0.4%; the mass-volume percentage of sodium citrate is 0.5-0.9%, preferably 0.6-0.8%, more preferably 0.7%; and the mass-volume percentage of calcium ascorbate is 0.3-0.5%, preferably 0.35-0.45%, more preferably 0.4%.

[0023] In this invention, the temperature of the color-protecting treatment in step (1) is 22~28℃, preferably 23~27℃, more preferably 24~26℃, and even more preferably 25℃, and the time is 10~20min, preferably 12~18min, more preferably 14~16min, and even more preferably 15min. Color protection can inhibit PPO enzyme activity.

[0024] In this invention, the maturation method in step (2) is steaming or boiling, and the steaming or boiling time is 4 to 11 minutes, preferably 4.5 to 8 minutes, and more preferably 5 minutes. Steaming or boiling can ensure starch gelatinization while reducing browning.

[0025] In this invention, the cooling and color-protecting temperature in step (3) is 22~28℃, preferably 23~27℃, more preferably 24~26℃, and even more preferably 25℃, and the time is 3~10min, preferably 4~7min, and even more preferably 5min. Cooling and color protection can further stabilize the color.

[0026] In this invention, the drying temperature in step (3) is 40~60℃, preferably 45~55℃, more preferably 50℃, and the drying time is 12~24h, preferably 13~20h, more preferably 14~17h, and more preferably 15h.

[0027] In this invention, the pulverization in step (3) is pulverization to 80-100 mesh, preferably 90 mesh.

[0028] This invention provides a method for preparing cooked taro powder.

[0029] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention. The banana taro variety used in the following embodiments is Qianbei banana taro, the color-protecting agents used are all food grade, and the equipment used is: a fruit and vegetable slicer (for slicing), an induction cooker and a steamer (for steaming), an electric heating drying oven (for drying), and a swing-type high-speed Chinese medicine pulverizer (for pulverizing).

[0030] Example 1

[0031] A method for preparing cooked taro flour, the steps of which are as follows: (1) Wash the surface dirt of fresh taro tubers with running water, peel them by hand or machine, and remove impurities from the skin; cut the peeled taro tubers into uniform thin slices with a thickness of 2mm using a fruit and vegetable slicer. (2) Rinse the banana taro slices obtained in step (1) with running water, and soak them in a compound color-protecting agent solution (0.3% (w / v) vitamin C, 0.5% (w / v) sodium citrate, 0.3% (w / v) calcium ascorbate, with water as the solvent) at a mass-volume ratio of 1 kg: 1.5 L. Treat them at 22°C for 10 min to obtain color-protected banana taro slices; (3) Place the color-protecting banana taro slices in a steamer and steam for 4 minutes to obtain cooked banana taro slices; (4) Immediately soak the cooked banana taro slices in the compound color-protecting agent solution at a mass-volume ratio of 1kg:3L, let them stand at 22℃ to cool and protect the color for 3 minutes, and place them in an electric heating drying oven at 40℃ for 12 hours until the moisture content is ≤10%. After drying, the banana taro slices are pulverized to 80 mesh in a swing-type high-speed Chinese medicine pulverizer to obtain cooked banana taro powder, which is then sealed and stored in a light-proof package.

[0032] Example 2

[0033] A method for preparing cooked taro flour, the steps of which are as follows: (1) Wash the surface dirt of fresh banana taro tubers with running water, peel them by hand or machine, and remove impurities from the skin; cut the peeled banana taro tubers into uniform thin slices with a thickness of 6mm using a fruit and vegetable slicer. (2) Rinse the banana taro slices obtained in step (1) with running water, and soak them in a compound color-protecting agent solution (0.5% (w / v) vitamin C, 0.9% (w / v) sodium citrate, 0.5% (w / v) calcium ascorbate, with water as the solvent) at a mass-volume ratio of 1 kg: 2.5 L. Treat them at 28°C for 20 min to obtain color-protected banana taro slices; (3) Place the color-protecting banana taro slices in a steamer and steam for 11 minutes to obtain cooked banana taro slices; (4) Immediately soak the cooked banana taro slices in the compound color-protecting agent solution at a mass-volume ratio of 1kg:5L, let them stand and cool at 28℃ for 10min for color protection, and place them in an electric heating drying oven at 60℃ for 24h until the moisture content is ≤10%. After drying, the banana taro slices are pulverized to 100 mesh in a swing-type high-speed Chinese medicine pulverizer to obtain cooked banana taro powder, which is then sealed and stored in a light-proof package.

[0034] Example 3

[0035] A method for preparing cooked taro flour, the steps of which are as follows: (1) Wash the surface dirt of fresh banana taro tubers with running water, peel them by hand or machine, and remove impurities from the skin; cut the peeled banana taro tubers into uniform thin slices with a thickness of 4mm using a fruit and vegetable slicer. (2) Rinse the banana taro slices obtained in step (1) with running water, and soak them in a compound color-protecting agent solution (0.4% (w / v) vitamin C, 0.7% (w / v) sodium citrate, 0.4% (w / v) calcium ascorbate, with water as the solvent) at a mass-volume ratio of 1 kg: 2 L. Treat them at 25°C for 15 min to obtain color-protected banana taro slices. (3) Place the color-protecting banana taro slices in a steamer and steam for 5 minutes to obtain cooked banana taro slices; (4) Immediately soak the cooked banana taro slices in the compound color-protecting agent solution at a mass-volume ratio of 1kg:4L, let them stand at 25℃ to cool and protect the color for 5 minutes, and then dry them in an electric heating drying oven at 50℃ for 15 hours until the moisture content is ≤10%. After drying, the banana taro slices are pulverized to 90 mesh in a swing-type high-speed Chinese medicine pulverizer to obtain cooked banana taro powder, which is then sealed and stored in a light-proof package.

[0036] Experimental Example 1: Screening of the Optimal Preparation Process of Taro Flour using Single-Factor and Orthogonal Experiments

[0037] (a) Color protection process

[0038] 1. Screening of composite color-protecting agents

[0039] Peeled taro tubers were sliced ​​evenly into 4mm thick slices using a fruit and vegetable slicer and rinsed continuously under running water. Food-grade vitamin C, sodium citrate, and calcium ascorbate were used as single-factor agents. The dosage of each single factor was varied, and the slices were then placed in the taro slices and left to stand at room temperature (25℃) for 15 minutes for color preservation. The lightness (L), red-green hue (a), and yellow-blue hue (b) at the center of the taro slices were measured and recorded using a colorimeter. Freshly cut taro slices were used as a standard sample for color difference comparison with the test samples. Deionized water immersion was used as a control group. The total color difference (ΔE) was used as the evaluation index, and the color-preserving agent with the best effect was selected for subsequent experiments. The experimental design is shown in Table 1, and the results are shown in Table 2.

[0040]

[0041] Table 1. Experimental factors and level design for color-protecting agents

[0042] Table 2. Effects of different concentrations of color-protecting agents on the color of banana and taro chips.

[0043] It can be seen that the total color difference value of the banana taro chips was the lowest under the color protection effects of 0.4% vitamin C, 0.7% sodium citrate, and 0.4% calcium ascorbate, respectively.

[0044] A composite color-protecting agent solution was further prepared using vitamin C, sodium citrate, and calcium ascorbate. The composite color-protecting agent solution contained 0.4% (w / v) vitamin C, 0.7% (w / v) sodium citrate, and 0.4% (w / v) calcium ascorbate. Using water as a control, the total color difference was measured according to the above method. The results showed that the total color difference of the banana taro slices treated with the composite color-protecting agent solution was 1.85, while the total color difference of the banana taro slices treated with water was 5.13. Therefore, the composite color-protecting agent solution has a significantly better color-protecting effect on banana taro slices than the single color-protecting agent treatment.

[0045] 2. Color protection time

[0046] 2.1 Color-protecting agent treatment sequence

[0047] To investigate the effects of steaming on the color and quality of whole banana taro powder, and whether the optimal time for soaking banana taro slices in the color-protecting agent is before or after steaming, the following single-factor experiments were designed to prepare whole banana taro powder. The color-protecting agent solution consisted of 0.4% (w / v) vitamin C, 0.7% (w / v) sodium citrate, and 0.4% (w / v) calcium ascorbate. Five groups of experiments were designed (see Table 3). The L, a, and b values ​​of the whole banana taro powder were measured using a colorimeter. Freeze-dried whole banana taro powder was used as a standard sample, and the color difference values ​​were compared with the test samples. The iodine blue value and total color difference were used as indicators for comprehensive evaluation.

[0048] The process for preparing taro whole powder by freeze drying is as follows: washing → peeling → slicing → color protection → steaming → cooling and color protection → freeze drying → pulverizing → sieving → finished product. The specific method is as follows: After washing and peeling the taro tubers, they are evenly sliced ​​into thin slices with a thickness of 4mm using a fruit and vegetable slicer. They are then soaked in a compound color protection agent of 0.4% (w / v) vitamin C, 0.7% (w / v) sodium citrate, and 0.4% (w / v) calcium ascorbate for 15 minutes, steamed for 5 minutes, and immediately placed in the compound color protection agent solution for cooling and color protection for 5 minutes. The taro slices with the surface water drained are evenly spread on a tray and placed in a vacuum freeze dryer for pre-freezing and drying. The drying process lasts for about 36 hours until the moisture content is below 10%. The freeze-dried taro slices are then pulverized in a high-speed cutting pulverizer and sieved through a 100-mesh sieve to obtain taro whole powder.

[0049] Determination of free starch iodine blue value: Maintain the constant temperature water bath at 70℃. Add 0.250 g of cooked taro powder and 50 mL of distilled water at 70℃ to a beaker, mix well, heat in the 70℃ water bath with continuous stirring for 5 min, remove and let stand for 1 min, then filter while hot. Take 1 mL of the filtrate, add 1 mL of 0.02 mol / L iodine solution, and then add distilled water to a final volume of 50 mL. Using the corresponding reagent blank, read the absorbance A at a wavelength of 650 nm.

[0050] Iodine blue value = absorbance A × 54.2 + 5

[0051] Table 3. Effect of the order of color-protecting agent treatment on the overall pink color of the banana taro.

[0052] / indicates that no processing has been performed.

[0053] The results are shown in Table 3 and Figure 1 As shown, it can be seen that a steaming process for taro slices is required during the preparation of whole potato flour. The high temperature of steaming can deactivate enzymes, terminate enzymatic browning, and prevent color browning during processing and storage, thus maintaining a stable color. Steaming taro slices can also promote starch gelatinization, which is helpful for subsequent processing of whole potato flour. The color-protecting agent is more effective when used before steaming (i.e., in the pretreatment stage) than when used after steaming. At the same time, immersing the taro slices in cold water with added color-protecting agent during the cooling process after steaming can effectively inhibit non-enzymatic browning and oxidative discoloration. Therefore, the taro slices are soaked in water with added color-protecting agent in both the pretreatment stage and the steaming and cooling stage.

[0054] 2.2 Color protection time before steaming

[0055] The study investigated the effects of different color-protecting times before steaming (5, 10, 15, 20, and 25 min) on the color of cooked taro powder. Except for the different color-protecting times before steaming and the uniform cooling color-protecting time of 10 min, the other steps and parameters were the same as in Example 3. The L, a, and b values ​​of the cooked taro powder were measured using a colorimeter. Freeze-dried taro powder was used as a standard sample, and the color difference values ​​were compared with the test sample. The total color difference was used as the evaluation index. The results showed that the total color difference values ​​were higher at color-protecting times of 5 min and 25 min (Table 4). Figure 2 Therefore, the factors that influence the color protection time of 10, 15, and 20 min in subsequent orthogonal experiments were selected.

[0056] Table 4. Effects of different color-protecting times on the color of fully ripe banana taro.

[0057] 2.3 Cooling and color protection time

[0058] The effects of different cooling and color-protecting times (5, 10, 20, 30, and 40 min) on the color of cooked whole-powder of taro were studied. Except for the different cooling and color-protecting times, the other steps and parameters were the same as in Example 3. The L, a, and b values ​​of the whole-powder of taro were measured using a colorimeter. Freeze-dried whole-powder of taro was used as a standard sample, and the color difference values ​​were compared with the test sample. The total color difference was used as the evaluation index. The results showed that as the cooling and color-protecting time increased, the total color difference value actually became higher, with a significant increase after 10 min (Table 5). Figure 3 The optimal cooling and color-preserving time for banana and taro slices, based on comprehensive screening, is less than 10 minutes.

[0059] Table 5. Effects of different cooling and color-preserving times (5–40 min) on the color of ripe banana taro.

[0060] Further, different cooling and color protection times (1, 3, 5, 7, 9 min) were set to screen the optimal range. The results are shown in Table 6. The optimal cooling and color protection time was 5 min. Finally, 3, 5, and 7 min were selected as factors for the subsequent orthogonal experimental level.

[0061] Table 6. Effects of different cooling and color-preserving times (1–9 min) on the color of ripe banana taro.

[0062] (ii) Slice thickness

[0063] Slice thickness directly affects drying efficiency, starch gelatinization degree, and final product quality. This study investigated the effect of different slice thicknesses (2, 4, 6, 8, and 10 mm) on the iodine blue value of cooked taro flour. Except for the slice thickness, all other steps and parameters were the same as in Example 3. The results are shown in Table 7 and... Figure 4 As shown, it can be seen that the iodine blue value generally increases with the increase of the slice thickness. After the slice thickness reaches 6 mm, the iodine blue value remains in a relatively stable range of 10.38~11.09. Slice thicknesses of 2, 4, and 6 mm were selected as factors for subsequent orthogonal experimental levels.

[0064] Table 7. Effect of different slice thicknesses on the iodine blue value of cooked taro flour

[0065] (iii) Steaming time

[0066] The study investigated the effect of different steaming times (5, 10, 15, 20, 25, and 30 min) on the color of cooked banana taro. Except for the steaming time, the other steps and parameters were the same as in Example 3. The results showed that the iodine blue value gradually increased with increasing steaming time, rising rapidly from 5 to 15 min, and then gradually slowing down after 20 min (Table 8). Figure 5 Therefore, cooking time of less than 15 minutes can significantly improve the overall pink color of taro while ensuring gelatinization.

[0067] Table 8. Effect of different cooking times (5-30 min) on the iodine blue value of cooked taro flour

[0068] Based on the above results, under the same conditions, the effects of different cooking times (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, and 14 min) on the iodine blue value of cooked taro flour were further investigated. The results showed that cooking taro slices promoted starch gelatinization, and the iodine blue value gradually increased with prolonged cooking time. After 5 min of cooking time, the increase in iodine blue value decreased, and the iodine blue value at 8 min of cooking time was lower than that at 7 min (Table 9). Figure 6 After 11 minutes, the increase in iodine blue value temporarily stabilized (images for 11-14 minutes were not taken, so the results are not shown). Cooking times of 5, 8, and 11 minutes were selected as factors for subsequent orthogonal experimental levels.

[0069] Table 9. Effect of different cooking times (0-14 min) on the iodine blue value of cooked taro flour

[0070] (iv) Drying temperature

[0071] The effect of different drying temperatures (40, 45, 50, 55, and 60℃) on the iodine blue value of cooked taro flour was studied. Except for the drying temperature, the other steps and parameters were the same as in Example 3. The results showed that the iodine blue value increased with increasing drying temperature. The increase was more significant between 40 and 50℃, while the change was smaller and tended to stabilize between 50 and 60℃ (Table 10). Figure 7 The hot air drying temperatures of 40, 50, and 60 were selected as factors for subsequent orthogonal experimental levels.

[0072] Table 10 Effect of different drying temperatures on the iodine blue value of cooked taro flour

[0073] (v) Drying time (dry until moisture content ≤10%)

[0074] The effects of different drying times (12, 15, 18, 21, and 24 hours) on the iodine blue value and moisture content of cooked taro flour were studied. Except for the drying time, the other steps and parameters were the same as in Example 3. The moisture content was determined using the direct drying method specified in GB 5009.3-2016, "National Food Safety Standard - Determination of Moisture in Food". X = (m1-m2) / (m1-m3)×100 In the formula, X—the moisture content in the sample, in grams per 100 grams (g / 100 g); m1—the mass of the weighing bottle and the sample, in grams (g); m2—the mass of the weighing bottle and the sample after drying, in grams (g); m3—the mass of the weighing bottle, in grams (g); 100—the unit conversion factor. When the moisture content is ≥1 g / 100 g, the calculation result is retained to three significant figures; when the moisture content is <1 g / 100 g, the calculation result is retained to two significant figures.

[0075] The results showed that the iodine blue value increased with increasing drying time, with a larger increase between 12 and 21 hours, and a smaller, more stable value after 24 hours. Conversely, the moisture content of the powder decreased with increasing drying time, stabilizing after 21 hours (Table 11). Based on the combined effects of the iodine blue value and moisture content, drying time parameters of 15, 18, and 21 minutes were selected as factors for subsequent orthogonal experiments.

[0076] Table 11 Effects of different drying times on the iodine blue value and moisture content of cooked taro flour

[0077] (vi) Orthogonal experiment to screen the optimal preparation process of taro cooked whole flour

[0078] Based on determining the optimal ranges for each factor using single-factor experiments: slice thickness (2, 4, and 6 mm), color-protecting time (10, 15, and 20 min), cooking time (5, 8, and 11 min), cooling color-protecting time (3, 5, and 7 min), drying temperature (40, 50, and 60 °C), and drying time (15, 18, and 21 h), an orthogonal experiment (L) was conducted. 27 (3 13 All experiments were repeated three times. The quality characteristics of the prepared taro whole powder were comprehensively evaluated based on the total color difference, iodine blue value, and moisture content, and the optimal preparation process for taro whole powder was selected. The experimental results showed that, considering both the color and moisture content of the whole powder, and ensuring good reconstitution and digestibility during subsequent processing, the optimal conditions were: slice thickness 4 mm, color protection time 15 min, cooking time 5 min, cooling and color protection time 5 min, drying temperature 50℃, and drying time 15 h (Tables 12 and 13).

[0079] Table 12 Factors and Levels in Orthogonal Experiments

[0080] Table 13 Results of Orthogonal Experiments

[0081] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing cooked taro flour, characterized in that, Includes the following steps: (1) After slicing the taro, soak it in a compound color-protecting agent solution to obtain color-protected taro slices; (2) The banana taro slices that have undergone color protection treatment are cooked to obtain cooked banana taro slices; (3) Soak cooked taro slices in the composite color-protecting agent solution to cool and protect the color, dry and pulverize to obtain cooked taro powder; The composite color-protecting agent includes vitamin C, sodium citrate, and calcium ascorbate.

2. The method according to claim 1, characterized in that, Before slicing in step (1), the taro is washed and peeled; the thickness of the slices is 2-6 mm.

3. The method according to claim 1, characterized in that, The composite color-protecting agent solution contains 0.3-0.5% by mass and volume of vitamin C, 0.5-0.9% by mass and volume of sodium citrate, and 0.3-0.5% by mass and volume of calcium ascorbate.

4. The method according to claim 1, characterized in that, The temperature for the color protection treatment in step (1) is 22~28℃ and the time is 10~20min.

5. The method according to claim 1, characterized in that, The cooking method described in step (2) is steaming or boiling, and the steaming or boiling time is 4 to 11 minutes.

6. The method according to claim 1, characterized in that, The cooling and color protection temperature in step (3) is 22~28℃, and the time is 3~10min.

7. The method according to claim 1, characterized in that, The drying temperature in step (3) is 40~60℃ and the time is 12~24h.

8. The method as described in claim 1, characterized in that, The pulverization mentioned in step (3) refers to pulverizing to 80~100 mesh.

9. A whole cooked taro powder prepared by the method according to any one of claims 1 to 8.

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