Natural fresh-keeping agent for fresh and wet rice noodles and fresh-keeping method for fresh and wet rice noodles

Abstract

The invention discloses a natural preservative for fresh wet rice noodles. The natural preservative is characterized by being a mixed extracting solution of ginkgo, lily and honeysuckle. The natural preservative can prolong the shelf life of the fresh and wet rice noodles. The invention further discloses a fresh-keeping method of the fresh and wet rice noodles. The fresh-keeping method comprises the following steps: putting the fresh and wet rice noodles into the natural fresh-keeping agent, and soaking for 1-2 minutes; and taking out, draining, sealing and packaging with a heat-resistant food plastic bag, sterilizing at high temperature, and cooling to obtain the product.

Description

Technical Field

[0001] The invention belongs to the technical field of food processing, and in particular relates to a natural preservative for fresh wet rice noodles and a method for preserving the fresh wet rice noodles. Background Art

[0002] Fresh wet rice noodles are made of rice as raw material, processed through production processes such as grinding, gelatinization, cooling, and undried rice noodles. Fresh wet rice noodles are popular with consumers because of their convenient processing, good taste and quality, but their moisture content is high (>60%), and they are easily contaminated by microorganisms and go bad, and their shelf life is extremely short. In recent years, my country has repeatedly experienced food poisoning incidents caused by edible fresh wet rice noodles, which has caused governments at all levels to attach great importance to them, and have promulgated fresh wet rice noodles production and management measures one after another. Therefore, research and development of fresh wet rice noodles preservation methods, improving the safety of fresh wet rice noodles, are conducive to promoting the healthy development of my country's fresh wet rice noodles processing industry, and have huge economic and social significance.

[0003] At present, the main method for preserving fresh wet rice noodles is acid treatment combined with heat sterilization, in which acid treatment generally uses chemical reagents such as potassium phosphate, sodium dehydroacetate, citric acid, etc. as preservatives for fresh wet rice noodles; however, this preservation method has problems such as short preservation time, low safety, and strong sour taste. Therefore, the development of natural preservatives that are both safe and do not affect the taste of fresh wet rice noodles is an inevitable trend in the development of fresh wet rice noodles. Summary of the invention

[0004] One of the purposes of the present invention is to provide a natural preservative for fresh wet rice noodles to prolong the shelf life of the fresh wet rice noodles.

[0005] A second object of the present invention is to provide a method for preserving fresh wet rice noodles.

[0006] To achieve the above first purpose, the present invention provides a natural preservative for fresh wet rice noodles, which is characterized by a mixed extract of ginkgo, lily and honeysuckle.

[0007] The invention uses the medicinal and edible materials, namely ginkgo, lily and honeysuckle, to extract the antibacterial components therein, and develops a natural preservative for fresh wet rice noodles. The three materials are compounded to play a synergistic role, greatly extending the shelf life of the fresh wet rice noodles. The natural preservative is applied to the preservation of fresh wet rice noodles, which can not only extend the shelf life of the fresh wet rice noodles, but also is safe and non-toxic, and has no obvious effect on the taste of the fresh wet rice noodles.

[0008] The preparation method of the mixed extract is as follows: ginkgo, lily and honeysuckle are mixed and then crushed to obtain mixed powder; edible ethanol is added to the mixed powder, hot reflux extraction is performed at 90-100°C, and then filtering and centrifuging are performed in sequence to obtain a clarified mixed extract.

[0009] Preferably, the mass ratio of the ginkgo, lily and honeysuckle is 1-3:1-2:1-3.

[0010] Preferably, the mixed powder is sieved through a 100-200 mesh sieve.

[0011] Preferably, the mass ratio of the mixed powder to edible ethanol is 1:1, and the concentration of the edible ethanol is 50-80 vol%.

[0012] Preferably, the hot reflux extraction is performed twice in succession, and each time lasts for 1 to 2 hours.

[0013] Furthermore, the mixed extract obtained by filtration and centrifugation is concentrated under reduced pressure to 1 / 5 to 1 / 10 of the original volume, and the obtained concentrated mixed extract is the natural preservative.

[0014] Preferably, the centrifugation is performed at 3000-5000 r / min for 10-20 min.

[0015] To achieve the above-mentioned second object, the present invention provides a method for preserving fresh wet rice noodles, which is characterized in that it comprises the following steps:

[0016] The fresh wet rice noodles are soaked in the natural preservative for 1 to 2 minutes; after being taken out and drained, they are sealed and packed in heat-resistant food plastic bags, sterilized at high temperature, and cooled to obtain the product.

[0017] The present invention has no restriction on the ratio of fresh wet rice noodles to the natural preservative during soaking, and the purpose of the present invention can be achieved by simply immersing the fresh wet rice noodles in the natural preservative.

[0018] Specifically, the high temperature sterilization is sterilization at 100° C. for 30 minutes.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. Compared with the preservatives potassium phosphate, sodium dehydroacetate and citric acid used in the prior art, the natural preservative of the present invention can achieve the purpose of extending the shelf life of fresh wet rice noodles, has no obvious effect on the taste of fresh wet rice noodles, and has no safety hazards, and has great development and application value.

[0021] 2. The present invention compounds ginkgo, lily and honeysuckle into a natural preservative, which extends the shelf life of fresh wet rice noodles to more than 15 days, which is much higher than the effect achieved by the preservatives made from the above three ingredients alone; this shows that ginkgo, lily and honeysuckle have a synergistic effect when mixed together. DETAILED DESCRIPTION

[0022] The technical scheme of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. The raw materials and reagents used in the following examples are all purchased from the market.

[0023] Example 1

[0024] (1) Preparation of natural preservatives:

[0025] Mix ginkgo, lily and honeysuckle in a mass ratio of 1:1:1, crush and sieve through 200 mesh to obtain mixed powder;

[0026] 60 vol% edible ethanol is added to the mixed powder at a mass ratio of 1:1, and hot reflux extraction is performed at 90°C for 2 hours. The hot reflux extraction is performed twice continuously, and the extracts are combined; filtered with a 200-mesh nylon cloth, and then centrifuged at 5000 r / min for 10 minutes to obtain a clarified mixed extract; the clarified mixed extract is concentrated under reduced pressure to 1 / 10 of the original volume to obtain a natural preservative, and the edible ethanol is recovered at the same time.

[0027] (2) Preservation of fresh wet rice noodles:

[0028] The fresh wet rice noodles are soaked in a natural preservative for 2 minutes; taken out and drained for 10 minutes, and then sealed and packaged in a heat-resistant food plastic bag, sterilized at 100° C. for 30 minutes, and the product is obtained after cooling.

[0029] Example 2

[0030] (1) Preparation of natural preservatives:

[0031] Mix ginkgo, lily and honeysuckle in a mass ratio of 3:2:3, crush and sieve through 100 mesh to obtain mixed powder;

[0032] 75 vol% edible ethanol is added to the mixed powder at a mass ratio of 1:1, and hot reflux extraction is performed at 100°C for 1 hour. The hot reflux extraction is performed twice continuously, and the extracts are combined; filtered with a 200-mesh nylon cloth, and then centrifuged at 3000 r / min for 20 minutes to obtain a clarified mixed extract; the clarified mixed extract is concentrated under reduced pressure to 1 / 5 of the original volume to obtain a natural preservative, and the edible ethanol is recovered at the same time.

[0033] (2) Preservation of fresh wet rice noodles:

[0034] The fresh wet rice noodles are soaked in a natural preservative for 2 minutes; taken out and drained for 10 minutes, and then sealed and packaged in a heat-resistant food plastic bag, sterilized at 100° C. for 30 minutes, and the product is obtained after cooling.

[0035] Comparative Example 1

[0036] The fresh wet rice noodles are not subjected to a fresh-keeping treatment and are directly sealed and packaged in a heat-resistant food plastic bag to obtain the product.

[0037] Comparative Example 2

[0038] Preservation of fresh wet rice noodles:

[0039] The fresh wet rice noodles are sealed and packed in a heat-resistant food plastic bag, sterilized at 100° C. for 30 minutes, and the product is obtained after cooling.

[0040] Comparative Example 3

[0041] (1) Preparation of natural preservatives:

[0042] Grind the ginkgo nuts and pass through a 200-mesh sieve to obtain ginkgo nut powder;

[0043] Add 60 vol% edible ethanol to ginkgo powder at a mass ratio of 1:1, perform heat reflux extraction at 90°C for 2 hours, perform heat reflux extraction twice continuously, and combine the extracts; filter with 200-mesh nylon cloth, and then centrifuge at 5000r / min for 10 minutes to obtain a clarified ginkgo extract; reduce the pressure and concentrate the clarified ginkgo extract to 1 / 10 of the original volume to obtain a ginkgo preservative, and recover the edible ethanol at the same time.

[0044] (2) Preservation of fresh wet rice noodles:

[0045] The fresh wet rice noodles are soaked in the ginkgo preservative for 2 minutes; taken out and drained for 10 minutes, and then sealed and packed in a heat-resistant food plastic bag, sterilized at 100° C. for 30 minutes, and the product is obtained after cooling.

[0046] Comparative Example 4

[0047] (1) Preparation of natural preservatives:

[0048] Crush the lily and pass it through a 200-mesh sieve to obtain lily powder;

[0049] 60 vol% edible ethanol is added to lily powder at a mass ratio of 1:1, and hot reflux extraction is performed at 90°C for 2 hours. The hot reflux extraction is performed twice continuously, and the extracts are combined; filtered with a 200-mesh nylon cloth, and then centrifuged at 5000 r / min for 10 minutes to obtain a clarified lily extract; the clarified lily extract is concentrated under reduced pressure to 1 / 10 of the original volume to obtain a lily preservative, and the edible ethanol is recovered at the same time.

[0050] (2) Preservation of fresh wet rice noodles:

[0051] The fresh wet rice noodles are soaked in a lily preservative for 2 minutes; taken out and drained for 10 minutes, and then sealed and packaged in a heat-resistant food plastic bag, sterilized at 100° C. for 30 minutes, and the product is obtained after cooling.

[0052] Comparative Example 5

[0053] (1) Preparation of natural preservatives:

[0054] The honeysuckle was crushed and passed through a 200-mesh sieve to obtain honeysuckle powder;

[0055] Add 60 vol% edible ethanol to honeysuckle pollen at a mass ratio of 1:1, perform hot reflux extraction at 90°C for 2 hours, perform hot reflux extraction twice continuously, and combine the extracts; filter with 200-mesh nylon cloth, and then centrifuge at 5000r / min for 10 minutes to obtain a clarified honeysuckle extract; reduce the pressure and concentrate the clarified honeysuckle extract to 1 / 10 of the original volume to obtain a honeysuckle preservative, and recover the edible ethanol at the same time.

[0056] (2) Preservation of fresh wet rice noodles:

[0057] The fresh wet rice noodles are soaked in a honeysuckle preservative for 2 minutes; taken out and drained for 10 minutes, and then sealed and packaged in a heat-resistant food plastic bag, sterilized at 100° C. for 30 minutes, and the product is obtained after cooling.

[0058] Comparative Example 6

[0059] Preservation of fresh wet rice noodles:

[0060] The fresh wet rice noodles are soaked in a potassium sorbate solution with a concentration of 0.05wt% for 2 minutes; taken out and drained for 10 minutes, and then sealed and packaged in a heat-resistant food plastic bag, sterilized at 100°C for 30 minutes, and the product is obtained after cooling.

[0061] Comparative Example 7

[0062] Preservation of fresh wet rice noodles:

[0063] The fresh wet rice noodles are soaked in a 0.1wt% sodium dehydroacetate solution for 2 minutes; taken out and drained for 10 minutes, and then sealed and packaged in a heat-resistant food plastic bag, sterilized at 100°C for 30 minutes, and the product is obtained after cooling.

[0064] Comparative Example 8

[0065] Preservation of fresh wet rice noodles:

[0066] The fresh wet rice noodles are soaked in a 1wt% citric acid solution for 2 minutes; taken out and drained for 10 minutes, and then sealed and packaged in a heat-resistant food plastic bag, sterilized at 100°C for 30 minutes, and the product is obtained after cooling.

[0067] Table 1

[0068]

[0069] Total colony count: The fresh wet rice noodle product is stored at room temperature for 2 days and then measured according to the national standard "National Food Safety Standard Food Microbiology Inspection Total Colony Count Determination" (GB4789.2-2022).

[0070] Safety of preservatives: Ginkgo, lily, and honeysuckle are both medicinal and edible materials, not food additives, and can be used in unlimited quantities, so they are safe; potassium sorbate and citric acid are food additives (see GB 2760-2014 National Food Safety Standard for the Use of Food Additives), among which potassium sorbate is used in limited quantities, so it is relatively safe, while citric acid is used in unlimited quantities, so it is safe; sodium dehydroacetate is a chemical drug, but is not within the scope of food additives specified in GB 2760-2014, so it is unsafe.

[0071] Shelf life: refers to the time that fresh wet rice noodles are stored at room temperature without obvious odor, surface bacteria spots, and color changes.

Claims

1. A natural preservative for fresh wet rice noodles, characterized in that A mixed extract of ginkgo, lily and honeysuckle.

2. The natural preservative according to claim 1, characterized in that: The preparation method of the mixed extract is as follows: ginkgo, lily and honeysuckle are mixed and then crushed to obtain mixed powder; edible ethanol is added to the mixed powder, hot reflux extraction is performed at 90-100°C, and then filtering and centrifuging are performed in sequence to obtain a clarified mixed extract.

3. The natural preservative according to claim 2, characterized in that: The mass ratio of the ginkgo, lily and honeysuckle is 1-3:1-2:1-3.

4. The natural preservative according to claim 3, characterized in that: The mass ratio of the mixed powder to edible ethanol is 1:1, and the concentration of the edible ethanol is 50-80 vol%.

5. The natural preservative according to claim 4, characterized in that: The mixed powder is passed through a 100-200 mesh sieve.

6. The natural preservative according to claim 5, characterized in that: The hot reflux extraction is performed twice continuously, and each time lasts for 1 to 2 hours.

7. The natural preservative according to claim 6, characterized in that: The centrifugation is carried out at 3000-5000 r / min for 10-20 min.

8. A method for preserving fresh wet rice noodles, characterized in that: The following steps are involved: The fresh wet rice noodles are soaked in the natural preservative according to claim 1 for 1 to 2 minutes; after being taken out and drained, they are sealed and packed in heat-resistant food plastic bags, sterilized at high temperature, and cooled to obtain the product.

9. The preservation method according to claim 8, characterized in that: High temperature sterilization is sterilization at 100°C for 30 minutes.

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