Fresh and wet sweet potato vermicelli and preparation method thereof

Abstract

The invention discloses fresh and wet sweet potato vermicelli and a preparation method thereof, the fresh and wet sweet potato vermicelli comprises the processing raw materials of sweet potato starch, domestic drinking water, an acidity regulator and a fresh-keeping preservative, the usage amount of the fresh-keeping preservative is 0.05-0.6% of the weight of the starch raw material, and the preparation method comprises the following steps: weighing the raw materials of the fresh and wet vermicelli, preparing starchy sauce, preparing dough, mixing slurry, curing and forming, and the like, thereby obtaining the fresh and wet sweet potato vermicelli. Aging the cured vermicelli for 1-2.5 hours in an environment of 10-1 DEG C, so as to obtain aged vermicelli; and cutting the aged vermicelli into strips, performing vacuum packaging, and performing pasteurization to obtain the product. In the preparation process of the fresh and wet sweet potato vermicelli, potassium cinnamate, thymol and aloe extract are added as fresh-keeping preservatives. The method overcomes the problem that chemical preservatives such as sodium dehydroacetate cannot be added into the fresh and wet sweet potato vermicelli, and prolongs the shelf life of the fresh and wet sweet potato vermicelli.

Description

Technical Field

[0001] The present invention belongs to the technical field of food processing, and particularly relates to a fresh wet sweet potato vermicelli and a preparation method thereof. Background Art

[0002] Fresh wet sweet potato vermicelli is a starch product in the form of filaments or strips processed from sweet potatoes and domestic drinking water; the sweet potato vermicelli has a soft, glutinous and smooth taste, and is often eaten in the form of sour and spicy noodles, hot pot noodles, etc. Moreover, compared with traditional dry vermicelli, fresh wet vermicelli does not need to be cooked and soaked for a long time before eating, making it more convenient to consume. Currently, fresh wet vermicelli has become a vermicelli product that the industry competes to develop, showing a broad market prospect.

[0003] Since wet vermicelli has a high water content, it is prone to microbial spoilage and deterioration. Preventing microbial spoilage is the key technical point for the fresh-keeping processing of wet vermicelli. Dehydroacetic acid and its sodium salt are no longer allowed to be used as preservatives in starch products such as vermicelli and bean threads, and the original related technologies using this as a preservative can no longer be used for the fresh-keeping of wet vermicelli. From the perspective of safe production, finding green, safe and healthy substitutes for dehydroacetic acid and its sodium salt and focusing on solving the technical problems of wet vermicelli fresh-keeping technology under the new standard are of great significance for promoting the green development of the fresh-keeping wet vermicelli industry.

[0004] Currently, the research and development on the processing of fresh wet vermicelli mainly focuses on the following aspects: (1) Thermal sterilization. Wang Pengkai disclosed a processing technology for fresh-keeping wet powder sheets and vermicelli. After vacuum-packing the wet vermicelli, it is put into a sterilization pot for sterilization treatment, and then frozen. After the freezing is completed, the product is stored at room temperature, and the shelf life can reach 1 year, and it can be eaten after boiling in hot water for less than 2 minutes (Chinese Patent CN202111268044.9); some scholars carried out sterilization treatment on fresh wet vermicelli at 95°C - 100°C, but the duration of the sterilization treatment was not disclosed in this invention patent (Chinese Patent CN202410265664.4). (2) By developing new sterilization technologies and equipment, such as developing an ultrasonic sterilization type packaging equipment for wet vermicelli (Chinese Patent CN202210276595.8). Chinese Patent CN202510441259.8 disclosed a wet ready-to-eat vermicelli and a preparation method thereof. In this method, high-concentration ozone water (>5mg / kg) is used to sterilize the starch raw material and the product respectively, and combined with a high-temperature steam process (105 - 115°C, 2 - 5 minutes) to prepare wet ready-to-eat vermicelli, and the shelf life of the product at room temperature storage is 3 - 6 months. (3) Soaking or spraying the cooked vermicelli with slightly acidic electrolyzed water to extend the shelf life of fresh wet sweet potato vermicelli without adding preservatives (Chinese Patent CN202010942524.8). (4) Using new preservatives. Chinese Patent CN202510364796.7 disclosed a fresh-keeping method for fresh wet vermicelli using licorice extract as a fresh-keeping preservative. Summary of the Invention

[0005] In view of this, one of the purposes of the present invention is to provide a preparation method of fresh and wet sweet potato vermicelli, adopting the combination method of "acidity regulator - preservative - vacuum packaging - pasteurization" to achieve the preservation and anti-corrosion of fresh and wet sweet potato vermicelli and extend its shelf life; the second purpose is to provide fresh and wet sweet potato vermicelli prepared by the above processing method.

[0006] The present invention provides a preparation method of fresh and wet vermicelli. The raw materials for preparing fresh and wet sweet potato vermicelli include sweet potato starch, domestic drinking water, acidity regulator and preservative. The preparation method includes:

[0007] S1: Weigh the raw materials of the fresh and wet sweet potato vermicelli, take 0.5 - 3.0% of the total weight of the sweet potato starch raw materials, add boiling water and stir quickly to make a paste, and then add the remaining raw materials, stir and add water to make a dough.

[0008] S2: Stir and mix the dough, acidity regulator, preservative and domestic drinking water in a certain proportion to obtain a starch slurry with a certain Baume degree.

[0009] S3: Pump the starch slurry into a ripening and forming device, and obtain ripened sweet potato vermicelli after ripening.

[0010] S4: Age the ripened sweet potato vermicelli in an environment of 10 - -1 °C for 1 - 2.5 h to obtain aged vermicelli.

[0011] S4: Cut the aged sweet potato vermicelli into strips and vacuum package it.

[0012] S5: Perform pasteurization on the vacuum-packaged sweet potato vermicelli.

[0013] Further, in step S2, the acidity regulator can be any one of citric acid, acetic acid, lactic acid or malic acid or a mixture thereof, and the pH of the starch slurry is adjusted to 3.8 - 5.5 by using the acidity regulator.

[0014] Further, in step S2, the preservative is at least one of potassium cinnamate, thymol, aloe extract or a mixture thereof, and the weight of the preservative is 0.5 - 2‰ of the weight of the sweet potato starch.

[0015] Further, in step S2, the preservative also includes at least one of gum arabic, gum dawadawa, gum karaya, gum tragacanth, alginate, octenyl succinic anhydride monoarabinogalactan or a mixture thereof, and its dosage is 1 - 10‰ of the weight of the sweet potato starch.

[0016] Further, in step S2, the Baume degree of the starch slurry is 17 - 24 °Bé.

[0017] Furthermore, in step S5, the vacuum-packed vermicelli is sterilized by a pasteurization device, and the working parameters are: a processing temperature of 85 to 95° C. and a time of 30 to 75 minutes.

[0018] The invention also provides fresh wet sweet potato vermicelli prepared according to the method.

[0019] The beneficial effects of the present invention are embodied in:

[0020] 1. Fresh wet vermicelli cannot be sterilized by high pressure steam due to its high moisture content and poor thermal stability of starch gel. Using the principle of microbial barrier technology, targeting the key barrier factors (pH, preservatives, oxygen, temperature) of fresh wet vermicelli spoilage, a combination of acidity adjustment, preservatives, vacuum packaging, and pasteurization is adopted to extend the shelf life of fresh wet sweet potato vermicelli.

[0021] 2. Food flavorings such as potassium cinnamate, thymol, and aloe extract are used for the preservation of fresh wet vermicelli, providing a practical reference for exploring substitutes for dehydroacetic acid and its sodium salt. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention is described in detail below through preferred embodiments. The examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0023] Unless otherwise specified, the various raw materials and equipment used in the following examples are commercially available products known in the art.

[0024] Example 1

[0025] This embodiment provides a processing technology for fresh wet sweet potato vermicelli, and the specific operations are as follows:

[0026] (1) Making gluten paste and dough: Weigh 5 kg of sweet potato starch, place in a stirring pot, add 50 kg of boiling water, and stir quickly to make the sweet potato starch gelatinize into gluten paste. Transfer the gluten paste to a stirring tank, then add 195 kg of sweet potato starch raw material, stir and add 220 kg of water to make a uniform and smooth dough;

[0027] (2) Prepare starch slurry. Continue to add water to the dough in step (1), stir and slurry, add 0.4 kg potassium cinnamate and 2.0 kg octenyl succinate monoarabic gum ester, adjust the pH to 4.0 with citric acid, add a certain amount of drinking water, and obtain a starch slurry with a Baume degree of 17°Bé.

[0028] (3) Cooking and shaping. The starch slurry in step (2) is pumped into a cooking and shaping device, and cooked to obtain cooked sweet potato vermicelli.

[0029] (4) Low-temperature aging. Place the ripened sweet potato vermicelli in an environment of 10 to -1 °C for 2.0 h to obtain the aged vermicelli.

[0030] (5) Cut the aged sweet potato vermicelli into strips, put them into a high-temperature cooking bag and carry out vacuum packaging.

[0031] (6) Pasteurization. Transfer the vacuum-packed sweet potato vermicelli to a pasteurization device for sterilization, and the treatment conditions are: treatment temperature 87 ± 2 °C, time 75 min.

[0032] This example also provides fresh and wet sweet potato vermicelli prepared by the above method.

[0033] Comparative Example 1

[0034] This comparative example provides a processing technology for fresh and wet sweet potato vermicelli, and the difference from Example 1 is only that: in step (2), 0.4 kg of potassium cinnamate is replaced by 0.4 kg of sodium dehydroacetate.

[0035] Comparative Example 2

[0036] This comparative example provides a processing technology for fresh and wet sweet potato vermicelli, and the difference from Example 1 is only that: when preparing the starch slurry in step (2), no acidity regulator is used to adjust its pH.

[0037] Comparative Example 3

[0038] This comparative example provides a processing technology for fresh and wet sweet potato vermicelli, and the difference from Example 1 is only that: the vacuum-packed sweet potato vermicelli is no longer subjected to pasteurization.

[0039] Example 2

[0040] This example provides a processing technology for fresh and wet sweet potato vermicelli, and the specific operation is as follows:

[0041] (1) Prepare the thickening paste and dough: Weigh 5 kg of sweet potato starch, place it in a stirring pot, add 50 kg of boiling water, and quickly stir evenly to gelatinize the sweet potato starch into a thickening paste. Transfer the thickening paste to a stirring tank, then add 195 kg of sweet potato starch raw material, and stir and add 220 kg of water to make a uniform and smooth dough;

[0042] (2) Prepare the starch slurry. Continuously add water to the dough in step (1), stir and mix to make a slurry, add 0.3 kg of thymol, 0.1 kg of aloe extract, 1.7 kg of dawsonia gum, adjust the pH to 4.0 with lactic acid, and add a certain amount of domestic drinking water to obtain a starch slurry with a Baume degree of 24 °Bé.

[0043] (3) Aging and shaping. The starch slurry in step (2) is pumped into an aging and shaping device, and after aging, cooked sweet potato vermicelli is obtained.

[0044] (4) Low-temperature aging. The cooked sweet potato vermicelli is aged in an environment of 10 to -1 °C for 1.0 h to obtain aged vermicelli.

[0045] (5) Cut the aged sweet potato vermicelli into strips, and pack it in a high-temperature cooking bag under vacuum.

[0046] (6) Pasteurization. The vacuum-packed sweet potato vermicelli is transferred to a pasteurization device for sterilization, and the treatment conditions are: treatment temperature 90 ± 2 °C, treatment time 45 min.

[0047] This example also provides fresh and wet sweet potato vermicelli prepared by the above method.

[0048] Comparative Example 4

[0049] This comparative example provides a processing technology for fresh and wet sweet potato vermicelli. The difference from Example 2 is only that: 1.7 kg of dawsonia gum was not added when preparing the starch slurry in step (2).

[0050] Example 3

[0051] This example provides a processing technology for fresh and wet sweet potato vermicelli. The specific operation is as follows:

[0052] (1) Prepare the thickening paste and dough: Weigh 1 kg of sweet potato starch, place it in a stirring pot, add 30 kg of boiling water, and quickly stir evenly to gelatinize the sweet potato starch into a thickening paste. Transfer the thickening paste to a stirring tank, then add 199 kg of sweet potato starch raw material, and stir and add 240 kg of water to make a uniform and smooth dough;

[0053] (2) Prepare the starch slurry. The dough in step (1) continues to be added with water, stirred and slurried, 0.4 kg of potassium cinnamate, 0.8 kg of aloe extract, and 0.2 kg of karaya gum are added, the pH is adjusted to 3.8 with citric acid, and then domestic drinking water is continuously added to obtain a starch slurry with a Baume degree of 20 °Bé.

[0054] (3) Aging and shaping. The starch slurry in step (2) is pumped into an aging and shaping device, and after aging, cooked sweet potato vermicelli is obtained.

[0055] (4) Low-temperature aging. The cooked sweet potato vermicelli is placed in an environment of 10 to -1 °C and aged for 1.0 h to obtain aged vermicelli.

[0056] (5) Cut the aged sweet potato vermicelli into strips, and pack it in a high-temperature cooking bag under vacuum.

[0057] (6) Pasteurization. Transfer the vacuum-packed sweet potato vermicelli to a pasteurization device for sterilization. The processing conditions are: processing temperature 93 ± 2 °C, processing time 30 min.

[0058] This example also provides fresh and wet sweet potato vermicelli prepared by the above method.

[0059] Example 4

[0060] This example provides a processing technology for fresh and wet sweet potato vermicelli. The specific operation is as follows:

[0061] (1) Prepare the thickening paste and dough: Weigh 6 kg of sweet potato starch, place it in a stirring pot, add 60 kg of boiling water, and quickly stir evenly to gelatinize the sweet potato starch into a thickening paste. Transfer the thickening paste to a stirring tank, then add 194 kg of sweet potato starch raw material, and stir and add 210 kg of water to make a uniform and smooth dough;

[0062] (2) Prepare the starch slurry. Continuously add water to the dough in step (1), stir and mix into a slurry, add 0.1 kg of thymol, 0.1 kg of arabic gum, 0.1 kg of tragacanth gum, adjust the pH to 5.5 with malic acid, and continue to add potable water to obtain a starch slurry with a Baume degree of 22 °Bé.

[0063] (3) Ripening and shaping. The starch slurry in step (2) is pumped into a ripening and forming device, and after ripening, the ripened sweet potato vermicelli is obtained.

[0064] (4) Low-temperature aging. Age the ripened sweet potato vermicelli in an environment of 10 to -1 °C for 2.5 h to obtain aged vermicelli.

[0065] (5) Cut the aged sweet potato vermicelli into strips, pack it into a high-temperature cooking bag, and perform vacuum packaging.

[0066] (6) Pasteurization. Transfer the vacuum-packed sweet potato vermicelli to a pasteurization device for sterilization. The processing conditions are: processing temperature 93 ± 2 °C, processing time 30 min.

[0067] This example also provides fresh and wet sweet potato vermicelli prepared by the above method.

[0068] Effect evaluation

[0069] For the vacuum-packed fresh and wet sweet potato vermicelli prepared in Examples 1 to 3 and Comparative Examples 1 to 4, the total number of colonies (lg CFU / g) after storage at room temperature (25 °C) for different days (30 to 270 d) was detected. The detection method was carried out in accordance with GB 4789.2-2022 "National Food Safety Standard Food Microbiology Examination Determination of Total Number of Colonies". The results are shown in Table 1 below.

[0070] Table 1 Total number of colonies of fresh wet sweet potato vermicelli stored at room temperature for different days (lg CFU / g)

[0071] 30d 60d 90d 120d 180d 270d Example 1 <1.0 <1.0 <1.0 1.9 3.3 4.9 Example 2 <1.0 <1.0 <1.0 2.2 3.4 4.7 Example 3 <1.0 <1.0 <1.0 <1.0 2.1 4.4 Example 4 <1.0 <1.0 <1.0 3.3 6.5 / Comparative Example 1 <1.0 <1.0 <1.0 1.6 3.1 5.3 Comparative Example 2 4.1 7.9 / / / / Comparative Example 3 <1.0 1.4 2.7 5.6 / / Comparative Example 4 <1.0 <1.0 1.5 3.8 8.9 /

[0072] As can be seen from Table 1, after the fresh wet sweet potato vermicelli is subjected to pH adjustment, addition of preservatives and pasteurization, in terms of the single index of the total number of colonies, the storage period at room temperature can reach 120 - 270 d. In addition, compared with Comparative Example 1, in Examples 1 - 4, potassium cinnamate, thymol, aloe extract, etc. are added as preservatives, which also have an obvious antibacterial effect on fresh wet sweet potato vermicelli. The preservation effect is equivalent to that of sodium dehydroacetate within 90 d. Within 90 - 180 d, its antibacterial effect is slightly lower than that of sodium dehydroacetate, but the total number of colonies of the samples is within the limit specified in GB 2713-2015 "National Food Safety Standard Starch Products". The results of Comparative Example 2 show that adjusting the pH to 4.0 plays an important role in exerting the antibacterial effect of potassium cinnamate. The results of Comparative Example 3 show that it is necessary to perform pasteurization after vacuum packaging of fresh wet sweet potato vermicelli, and pasteurization can significantly improve the antibacterial effect of potassium cinnamate and extend the shelf life of fresh wet sweet potato vermicelli. The results of Comparative Example 4 show that adding gum dawai to the formula of the preservative can significantly improve the antibacterial performance and extend the shelf life. On the basis of the same addition amount of potassium cinnamate in Example 1, Example 3 additionally adds aloe extract accounting for 4‰ of the weight of the starch raw material, further improving its antibacterial effect, and the total number of colonies within 270 d at room temperature is much lower than that of other sample groups.

[0073] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation method of fresh and wet sweet potato vermicelli, characterized in that, The raw materials for preparing the fresh wet sweet potato vermicelli include sweet potato starch, acidity regulator and preservative, and the preparation method includes: S1: Weigh the raw materials for the fresh wet sweet potato vermicelli. Take 0.5-3.0% of the sweet potato starch by weight of the sweet potato starch input, add boiling water and stir quickly to make a paste, then add the remaining amount of sweet potato starch raw materials, stir and add water to make a dough. S2: Stir and mix the dough, acidity regulator, preservative, and domestic drinking water in a certain proportion to obtain a starch slurry with a certain Baume degree. S3: Pump the starch slurry into a ripening and forming device, and obtain ripened sweet potato vermicelli through heating and ripening. S4: Age the ripened sweet potato vermicelli in an environment of 10 to -1 °C for 1 to 2.5 h to obtain aged vermicelli. S4: Cut the aged sweet potato vermicelli into strips and vacuum package them. S5: Perform pasteurization on the vacuum-packed sweet potato vermicelli.

2. The preparation method of the fresh and wet sweet potato vermicelli according to claim 1, wherein, Use an acidity regulator (citric acid, acetic acid, lactic acid or malic acid) to adjust the pH of the starch slurry to 3.8-5.

5.

3. The preparation method of the fresh and wet sweet potato vermicelli according to claims 1 to 2, characterized in that, The preservative is at least one of potassium cinnamate, thymol, aloe extract or a mixture thereof, and the weight of the preservative is 0.5-6‰ of the weight of the sweet potato starch raw materials.

4. The preparation method of fresh and wet sweet potato vermicelli according to claims 1 to 3, characterized in that, The preservative also includes at least one of gum arabic, gum dawadawa, gum karaya, gum tragacanth, alginate, octenyl succinic anhydride mono arabic gum ester or a mixture thereof, and its dosage is 1-10‰ of the weight of the sweet potato starch raw materials.

5. The preparation method of fresh and wet sweet potato vermicelli according to claim 1, characterized in that, In step S2, the Baume degree of the starch slurry is 17-24 °Bé.

6. The preparation method of fresh and wet sweet potato vermicelli according to claim 1, characterized in that, In step S5, the vacuum-packed vermicelli is sterilized by a pasteurization device, and the working parameters are: the treatment temperature is 85-95 °C, and the time is 30-75 min.

7. A fresh and wet sweet potato vermicelli, characterized in that, Prepared by the preparation method of the fresh wet sweet potato vermicelli according to any one of claims 1-6.