A method for improving the frozen raw blank steamed stuffed bun freezing storage stability

Abstract

The application discloses a method for improving the frozen storage stability of frozen raw steamed stuffed buns, and belongs to the field of steamed stuffed bun food processing. The method comprises the following raw materials: rice wine fermentation juice, rice, bran, sugar, salt, flour and water. The rice wine fermentation juice is obtained by uniformly stirring and fermenting rice wine, porridge, bran and water and then extruding and filtering. The wheat flour, rice wine fermentation juice, salt and sugar are mixed to form a dough. The dough is fermented, rolled, cut, wrapped, proofed and quickly frozen to obtain the frozen raw steamed stuffed buns. The frozen raw steamed stuffed buns are directly stored in a freezer after quick freezing. The frozen raw steamed stuffed buns are directly taken out from the freezer for steaming when eaten. The method for preparing the frozen raw steamed stuffed buns with the frozen storage stability provided by the application does not rely on additives or modifiers, but only uses traditional fermentation agent rice wine fermentation juice and optimizes the fermentation mode. The method improves the air retention property and frozen storage stability of the raw steamed stuffed buns, and the steamed raw steamed stuffed buns can maintain good specific volume and whiteness. The application can be applied to frozen foods, and is conducive to promoting the industrialization and large-scale production of the frozen raw steamed stuffed buns.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for improving the frozen raw steamed stuffed buns freezing stability, belonging to the field of steamed stuffed bun food processing. BACKGROUND

[0002] Steamed stuffed bun is a traditional Chinese characteristic food, according to records, originated in the Three Kingdoms period with stuffing steamed buns. Compared with steamed buns, steamed stuffed bun skin stuffing has both, is more delicious and nutritious, and has high added value, and is deeply loved by Chinese people. At present, the main production and operation mode of steamed stuffed bun is family or handwork workshop for hand production, and it is sold now. Its main disadvantage is low efficiency, and it is difficult to guarantee the health and safety. Some central kitchens are steamed in advance and distributed to stores, and then reheated. The steamed stuffed bun after reheating has poor taste.

[0003] With the development of frozen dough technology, it provides technical support for the industrialization and standardization of steamed stuffed bun production. The frozen steamed stuffed bun on the market is roughly divided into two types: one is steamed after quick freezing, which is sticky after steaming and has poor taste; the other is raw steamed stuffed bun, which needs to be thawed and leavened before steaming, increasing the workload and not being simple and convenient. In order to overcome the problem of frozen storage deterioration, the existing frozen raw steamed stuffed bun production enterprises usually introduce certain food additives.

[0004] Jiuniang fermentation juice is the raw material for making Jiuniang steamed buns in Jiangsu and Zhejiang regions. It is obtained by filtering rice wine, bran and porridge fermentation. The steamed buns fermented by Jiuniang fermentation juice have a very large specific volume, which cannot be achieved by traditional leavening agents. However, there are few reports on the research and application of Jiuniang fermentation juice as a traditional food raw material to improve the freezing stability of frozen raw steamed stuffed buns.

[0005] At present, the application cases of Jiuniang fermentation juice are mainly in Jiuniang steamed buns. The patent with application number 202010115890.6 discloses a preparation method of whole wheat flour fermentation juice steamed buns. The whole wheat flour and fermentation juice are mixed to form a dough, and then fermented and steamed to obtain whole wheat flour fermentation juice steamed buns. The whole wheat flour fermentation juice steamed buns prepared by the patent have stable quality, rich flavor, and better elasticity, toughness and other characteristics, but are still limited to the application of Jiuniang fermentation juice in steamed buns.

[0006] Regarding the frozen raw buns technology, the existing patents and technologies mainly focus on improvers and steaming technology after thawing and leavening. Application No. 201910847926.7 discloses a frozen raw bun dough and a preparation method thereof. The patent uses a compound sugar and a compound frozen dough improver to prepare the frozen raw bun dough, thereby improving the stability of the frozen dough. However, the use of too many improvers or additives does not conform to the current development trend of zero addition in the food field in modern life when consumers pursue consumption concepts. Moreover, the patent needs to be steamed after thawing and leavening. Application No. 202011034923.0 discloses a preparation method of old dough frozen raw buns. The method uses a traditional leavening agent of old dough to make the raw buns after steaming achieve the taste and quality of fresh buns. However, the raw buns also need to be thawed before steaming. Application No. 201810587806.3 discloses a frozen raw bun improver. The raw buns are directly steamed by using a compound enzyme and an improver, thereby retaining the taste and flavor of fresh buns. However, too many compound enzymes and improvers are contrary to the current trend of zero addition in the food field.

[0007] In view of the quality improvement of frozen raw buns, many methods achieve the improvement by adding improvers. However, the use of too many improvers is contrary to the green and healthy diet concept pursued by consumers. SUMMARY

[0008] To solve the above problems, the present application starts from the traditional leavening agent Jiujiang fermentation juice and provides a method for improving the frozen storage stability of frozen raw buns. The method does not use additives and effectively improves the quality deterioration of raw buns during frozen storage, thereby improving the frozen storage stability of raw buns and further improving the quality of raw buns.

[0009] The first object of the present application is to provide a method for improving the frozen storage stability of frozen raw buns to solve the problem of quality deterioration during the frozen storage process of existing frozen raw buns. The method uses Jiujiang fermentation juice fermentation technology to mix Jiujiang fermentation juice, wheat flour, sugar, and salt to obtain a mixed dough, followed by leavening, calendering, dividing, and packaging to obtain raw buns; the obtained raw buns are leavened again, frozen, and obtained as frozen raw buns.

[0010] The Jiujiang fermentation juice is prepared by the following method:

[0011] The Jiujiang fermentation juice is prepared by the following method:

[0012] In an embodiment of the present application, the wheat flour, Jiujiang fermentation juice, sugar, and salt are mixed in a weight ratio of 80-120 parts, 50-56 parts, 2-10 parts, and 0.4-2 parts, respectively.

[0013] In one embodiment of the present application, the number of yeast in the wine fermentation juice is greater than 1 x 10 7 CFU / ml.

[0014] The second object of the present application is to further provide a method for preparing frozen raw steamed buns which are stable in freezing and storage, and the specific steps of the method include:

[0015] (1) Preparation of rice wine: add koji, steamed glutinous rice and water, mix uniformly, and place in a constant temperature incubator for a period of time to obtain rice wine;

[0016] (2) Preparation of wine fermentation juice: add rice wine, porridge, bran and water, mix uniformly, and place in a fermentation box for a period of time to obtain wine fermentation juice;

[0017] (3) Preparation of dough: wheat flour, wine fermentation juice, sugar and salt are placed in a dough mixing pot and stirred to obtain a mixed dough for making steamed buns; then the obtained mixed dough is placed in a constant temperature and humidity fermentation box for a certain period of time;

[0018] (4) Molding of raw steamed buns: the fermented dough is rolled, divided and molded;

[0019] (5) Fermentation of raw steamed buns: the molded steamed buns are placed in a constant temperature and humidity fermentation box, and then the fermented steamed buns are placed in a quick-freezing refrigerator for quick-freezing to obtain frozen raw steamed buns.

[0020] In one embodiment of the present application, in the preparation of rice wine, the weight ratio of raw materials dry glutinous rice, water and koji is 700-1000 parts: 200-1200 parts: 4-8 parts.

[0021] In one embodiment of the present application, the koji is Angel sweet koji.

[0022] In one embodiment of the present application, the preparation of rice wine specifically includes: dry glutinous rice is soaked in water for 12-48 h in advance, then steamed for 30-60 min to obtain glutinous rice, and then 0.2-0.6% of the mass of dry glutinous rice of koji and a certain amount of water are added, mixed uniformly and fermented for 24-60 h.

[0023] In one embodiment of the present application, in the preparation of wine fermentation juice, the fermentation raw materials of wine fermentation juice are composed of the following components by weight ratio: 100-750 parts of rice wine, 0-70 parts of bran, 0-125 parts of porridge (calculated as dry rice), and 100-800 parts of water.

[0024] In one embodiment of the present application, in the preparation of wine fermentation juice, the fermentation raw materials of wine fermentation juice are preferably: 125-250 parts of rice wine, 75-125 parts of porridge (calculated as dry rice), 10-30 parts of bran, and 300-500 parts of water.

[0025] In one embodiment of the present application, the fermentation raw material of the wine lees fermentation liquor is further preferably: rice wine 250 parts, porridge 75 parts, bran 30 parts, and water 500 parts.

[0026] In one embodiment of the present application, the mass ratio of dry rice and water used in the preparation of the porridge is 1:5.

[0027] In one embodiment of the present application, in the preparation of the wine lees fermentation liquor, the fermentation time in the wine lees fermentation liquor fermentation box is 8-24 h, the fermentation box temperature is 25-38℃, then the raking is carried out at room temperature, and the raking is carried out 3-6 times within 1 h.

[0028] In one embodiment of the present application, in the preparation of the dough, the dough raw material is composed of the following parts by weight: wheat flour 80-120 parts, wine lees fermentation liquor 50-54 parts, sugar 4-10 parts, and salt 0.4-1 part.

[0029] In one embodiment of the present application, in the preparation of the dough, the dough stirring and kneading time is 8-16 min, and the stirring and kneading is carried out in a kneader.

[0030] In one embodiment of the present application, in the preparation of the dough, it further comprises: mixing and kneading a part of the wheat flour with other raw materials to obtain a dough initial product, then placing the dough initial product in a constant temperature and humidity fermentation box for a certain time, and then continuously adding another part of the wheat flour and kneading to obtain the dough.

[0031] In one embodiment of the present application, in the preparation of the dough, the constant temperature in the constant temperature and humidity box is 26-38℃, the constant humidity is 70-90% RH, the fermentation time is 1-4 h, and the fermentation is carried out in the constant temperature and humidity box; or the fermentation is carried out at 4℃ for 24 h.

[0032] In one embodiment of the present application, in the forming of the green steamed stuffed buns, the face block segmentation weight is 30-70 g.

[0033] In one embodiment of the present application, in the fermentation of the green steamed stuffed buns, the constant temperature in the constant temperature and humidity box is 26-38℃, the constant humidity is 70-90% RH, the fermentation time is 20-80 min, the volume of the steamed stuffed buns after fermentation is 1.4-2.2 times of the initial volume, the fermentation is carried out in the constant temperature and humidity box, the quick-freezing temperature is below -35℃, and when the center temperature of the steamed stuffed buns drops to -18℃, the steamed stuffed buns are transferred to a refrigerator at -18℃ for frozen storage.

[0034] The third object of the present application is to provide a frozen green steamed stuffed bun product with frozen storage stability prepared based on the above method.

[0035] The fourth object of the present application is to provide the application of the above frozen green steamed stuffed bun product with frozen storage stability in the field of food.

[0036] Advantages of the present application:

[0037] 1) The method can effectively improve the shrinkage and collapse of fermented flour food during frozen storage: During frozen storage, the recrystallization of ice crystals and the migration of water weaken the gluten network structure. And frozen storage reduces the protein content of the dough, reduces the molecular weight of gluten protein, and increases the content of free sulfhydryl groups. While using the method described in the present application, the use of rice wine fermentation juice can reduce water migration and strengthen the gluten network, effectively improving the quality of steamed buns during frozen storage.

[0038] 2) The product batch has good stability and high safety, and can replace food additives to play a role: The use of traditional leavening agents is natural and green, and does not require chemical addition, which can effectively improve the frozen storage stability of frozen raw steamed buns.

[0039] 3) The product is more nutritious, and the final product contains the nutritional value of wheat flour and rice wine, rich in B vitamins, minerals and polyphenol active substances. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The figure is a comparison of the whiteness changes of each example and the comparative example during frozen storage.

[0041] Figure 2 The figure is a cross-sectional scanning diagram of Example 1(A) and Comparative Example 1(B) after frozen storage for 4 weeks. DETAILED DESCRIPTION

[0042] The present application will be further described in conjunction with the examples below, but the scope of protection does not limit to the content described in the examples.

[0043] The test methods used in the examples and comparative examples of the present application are as follows:

[0044] Method for determining the specific volume of steamed buns: The volume was determined using a Volscan Profiler 300 volume tester, and the parameters were set as follows: rotation speed 1 r / s, descending distance 1 mm / s. The mass of the steamed buns was weighed using a balance, accurate to 0.1 g, and the specific volume (v / m) of the steamed buns was calculated. Each sample was repeated six times to obtain the average value.

[0045] The determination method of the steamed stuffed bun texture is as follows: the steamed stuffed bun is cooled at room temperature for 30 min, and then is tested by using a TA-XT Plus texture analyzer, the whole steamed stuffed bun is placed on a support table, each sample is tested in parallel for 6 times to obtain an average value. The determination parameters are as follows: a P / 100 probe is used, the pre-test, test and post-test speeds are 5.0 mm / s, 1.0 mm / s and 5.0 mm / s respectively, the compression ratio is 50%, the trigger force is 8 g, the time interval of two compressions is 5 s, and the data acquisition speed is 200 pps. The measurement index is mainly hardness. The hardness represents the softness of the steamed stuffed bun, and the lower the value is, the softer the steamed stuffed bun is. According to the method, the product physical property quality is significantly better than that of the control group.

[0046] The determination method of the steamed stuffed bun color is as follows: the color of the steamed stuffed bun is determined by using a color difference meter, L* is recorded as the brightness of the steamed stuffed bun, a plurality of points on the same steamed stuffed bun are determined, and an average value is obtained.

[0047] The sensory score is explained as follows:

[0048]

[0049]

[0050] The embodiments and the comparative examples of the present application are explained and described by taking the following steamed stuffed bun as an example:

[0051] The process of the glutinous rice prepared by steaming the dry glutinous rice in the following examples is as follows: the dry glutinous rice is soaked in water for 24 h, and then is steamed for 40 min. In the soaking process, the water can cover the glutinous rice.

[0052] Example 1

[0053] A method for improving the frozen raw steamed stuffed bun freezing stability, comprising the following steps:

[0054] (1) Preparation of rice wine: 1000 parts of glutinous rice prepared by steaming dry glutinous rice, 4 parts of Angel sweet wine starter, and 200 parts of water are weighed and mixed uniformly, and then are fermented in a fermentation box at 30 DEG C for 48 h.

[0055] (2) Preparation of rice wine fermentation juice: 250 parts of rice wine in step (1), 75 parts of porridge (the weight of the porridge is calculated according to the dry rice weight, and the ratio of dry rice and water in the porridge is 1:5), 30 parts of bran, and 500 parts of water are weighed and mixed uniformly, and then are fermented in a fermentation box at 32 DEG C for 12 h.

[0056] (3) Preparation of rice wine dough: 100 parts of wheat flour, 54 parts of rice wine fermentation juice obtained in step (2), 4 parts of sugar, and 0.4 parts of salt are placed in a dough kneading pot, and then are kneaded for 10 min to obtain rice wine dough.

[0057] (4) The steamed buns obtained in step (3) are fermented at 32°C and 85% RH for 2.5 h, then rolled and degassed, divided into 50 g portions, and shaped, and then allowed to rise at 32°C and 85% RH for 40 min. The buns are then frozen in a refrigerator at -40°C for 2 h until the center temperature of the buns reaches -18°C.

[0058] (5) The buns obtained in step (4) are stored at -18°C to obtain the finished frozen raw buns. The following indicators are measured periodically.

[0059] Textural indicators: the full texture parameters reflect the hardness and chewiness of the raw buns (see Table 1);

[0060] Specific volume indicators: the volume change of the buns during frozen storage (see Table 2);

[0061] Sensory indicators: appearance, color, internal structure, etc. (see Tables 3-5);

[0062] The frozen raw buns with frozen storage stability made according to this embodiment 1 are stored at -18°C for 6-8 weeks, and after steaming, the skin is smooth, the whiteness is close to that of freshly steamed buns, the appearance is good, the internal structure is uniform, the chewiness is moderate, and the palatability is still acceptable.

[0063] Example 2

[0064] A method for improving the frozen storage stability of frozen raw buns, according to embodiment 1, with the only difference being that in step (2) the raw materials for preparing the fermented juice are 125 parts of rice wine, 125 parts of porridge (the weight of the dry rice is calculated in parts, and the ratio of porridge dry rice to water is 1:5), 30 parts of bran, and 375 parts of water. The following indicators are measured periodically.

[0065] Textural indicators: the full texture parameters reflect the hardness and chewiness of the raw buns (see Table 1);

[0066] Specific volume indicators: the volume change of the buns during frozen storage (see Table 2);

[0067] Sensory indicators: appearance, color, internal structure, etc. (see Tables 3-5);

[0068] The frozen raw buns with frozen storage stability made according to this embodiment 2 are stored at -18°C for 4-6 weeks.

[0069] Example 3

[0070] A method for improving the frozen raw steamed stuffed bun storage stability, referring to example 1, the difference is only in the preparation of the raw materials in step (2) of the wine brewing juice preparation, rice wine 200 parts, porridge 100 parts (the weight of the porridge is calculated by the weight of the dry rice, the ratio of dry rice and water for making porridge is 1:5), bran 30 parts, water 450 parts. The following indicators are measured regularly.

[0071] Texture index: the whole texture parameter reflects the hardness, chewiness and other characteristics of the raw steamed stuffed bun (see Table 1);

[0072] Specific volume index: the volume change of the steamed stuffed bun during frozen storage (see Table 2);

[0073] Sensory index: appearance, color, internal structure, etc. (see Tables 3-5);

[0074] The frozen raw steamed stuffed bun with storage stability made by this example 3 is preserved at-18℃ for 5-7 weeks.

[0075] Example 4

[0076] A method for improving the frozen raw steamed stuffed bun storage stability, referring to example 1, the difference is only in the preparation of the raw materials in step (2) of the wine brewing juice preparation, rice wine 750 parts, bran 30 parts, porridge 0 parts, water 400 parts. The following indicators are measured regularly.

[0077] Texture index: the whole texture parameter reflects the hardness, chewiness and other characteristics of the raw steamed stuffed bun (see Table 1);

[0078] Specific volume index: the volume change of the steamed stuffed bun during frozen storage (see Table 2);

[0079] Sensory index: appearance, color, internal structure, etc. (see Tables 3-5);

[0080] The frozen raw steamed stuffed bun with storage stability made by this example 4 is preserved at-18℃ for 4-6 weeks.

[0081] Example 5

[0082] A method for improving the frozen raw steamed stuffed bun storage stability, referring to example 1, the difference is only in the preparation of the raw materials in step (2) of the wine brewing juice preparation, rice wine 250 parts, porridge 75 parts (the weight of the porridge is calculated by the weight of the dry rice, the ratio of dry rice and water for making porridge is 1:5), bran 60 parts, water 500 parts, the following indicators are measured regularly.

[0083] Texture index: the whole texture parameter reflects the hardness, chewiness and other characteristics of the raw steamed stuffed bun (see Table 1);

[0084] Specific volume index: the volume change of the steamed stuffed bun during frozen storage (see Table 2);

[0085] Sensory index: appearance, color, internal structure, etc. (see Tables 3-5);

[0086] The frozen raw buns made by this example 5 were stored at -18℃ for 4-6 weeks.

[0087] Example 6

[0088] A method for improving the frozen raw buns' freeze-thaw stability (cold storage dough fermentation), referring to example 1, the only difference is that the preparation of step (3) of the wine lees dough is adjusted: 70 parts of flour, 54 parts of wine lees juice obtained in step (2), 4 parts of sugar, 0.4 parts of salt, and the dough is stirred and fermented at 32℃, 85% RH for 2h. Then add 30 parts of flour to the kneading pot and knead for 10min to get the wine lees dough. The following indicators are measured regularly.

[0089] Texture index: the whole texture parameters reflect the hardness, chewiness and other properties of the raw buns (see Table 1);

[0090] Specific volume index: volume change of buns during freeze-thaw storage (see Table 2);

[0091] Sensory index: appearance, color, internal structure, etc. (see Tables 3-5);

[0092] The frozen raw buns made by this example 6 were stored at -18℃ for 4-6 weeks.

[0093] Example 7

[0094] A method for improving the frozen raw buns' freeze-thaw stability (cold storage dough fermentation), referring to example 1, the only difference is that the preparation of step (3) of the wine lees dough is adjusted: 100 parts of flour, 54 parts of wine lees juice obtained in step (2), 4 parts of sugar, 0.4 parts of salt, and the dough is placed in the kneading pot and kneaded for 10min to get the wine lees dough. The dough is fermented at 4℃ for 24h. The following indicators are measured regularly.

[0095] Texture index: the whole texture parameters reflect the hardness, chewiness and other properties of the raw buns (see Table 1);

[0096] Specific volume index: volume change of buns during freeze-thaw storage (see Table 2);

[0097] Sensory index: appearance, color, internal structure, etc. (see Tables 3-5);

[0098] The frozen raw buns made by this example 7 were stored at -18℃ for 6-8 weeks, and after steaming, the skin was smooth, the whiteness was close to that of freshly steamed, the appearance was good, the internal structure was uniform, the chewiness was moderate, and the palatability was still acceptable.

[0099] Example 8

[0100] A method for improving the frozen raw steamed stuffed bun's frozen storage stability (frozen dough fermentation), refer to example 1, the difference is only in the preparation of step (3) of the starter dough: 70 parts of flour, 54 parts of the starter juice obtained in step (2), 4 parts of sugar, 0.4 parts of salt, and the dough is stirred and stored at 4℃ for 24h. Then add 30 parts of flour into the kneading pot and knead for 10min to obtain the starter dough. The following indicators are measured regularly.

[0101] Textural indicators: the whole texture parameters reflect the hardness, chewiness and other properties of the raw steamed stuffed bun (see Table 1);

[0102] Specific volume indicators: the volume change of the steamed stuffed bun during frozen storage (see Table 2);

[0103] Sensory indicators: appearance, color, internal structure, etc. (see Tables 3-5);

[0104] The frozen raw steamed stuffed bun with frozen storage stability made by this example 8 is stored at-18℃ for 5-7 weeks.

[0105] Comparative example 1 (dry yeast)

[0106] The processing process of the frozen raw steamed stuffed bun includes the following steps:

[0107] (1) Preparation of the dough: 100 parts of flour, 52 parts of water, 1.2 parts of dry yeast, 4 parts of sugar, 0.4 parts of salt, put into the kneading pot, and knead for 10min to obtain the dough.

[0108] (2) Leavening and freezing of the steamed stuffed bun: the dough obtained in step (1) is fermented at 32℃, 85% RH for 2.5h, then stretched and vented, divided into 50g of sub-buns, shaped, and then leavened at 32℃, 85% RH for 40min. Then put into the-40℃ refrigerator and freeze for 2h until the center temperature of the steamed stuffed bun reaches-18℃.

[0109] (3) Store the steamed stuffed bun obtained in step (2) at-18℃ to obtain the frozen raw steamed stuffed bun product. The following indicators are measured regularly.

[0110] Textural indicators: the whole texture parameters reflect the hardness, chewiness and other properties of the raw steamed stuffed bun (see Table 1);

[0111] Specific volume indicators: the volume change of the steamed stuffed bun during frozen storage (see Table 2);

[0112] Sensory indicators: appearance, color, internal structure, etc. (see Tables 3-5);

[0113] The frozen raw steamed stuffed bun made by this comparative example 1 is stored at-18℃ for 1-2 weeks, and after steaming, the skin shrinks and collapses, the skin turns yellow, the internal structure is rough, and the taste is hard, which has reached an unacceptable state.

[0114] Comparative Example 2 (semi-dry yeast)

[0115] The processing procedure of the frozen raw steamed buns includes the following steps:

[0116] (1) Preparation of the dough: 100 parts of flour, 52 parts of water, 1.2 parts of semi-dry yeast, 4 parts of sugar, and 0.4 parts of salt were placed in a kneading pot and kneaded for 10 min to obtain a dough.

[0117] (2) Leavening and freezing of the steamed buns: the dough obtained in step (1) was leavened at 32°C and 85% RH for 2.5 h, then was rolled and degassed, divided into 50 g of sub-doughs, shaped, and then leavened at 32°C and 85% RH for 40 min. The steamed buns were then frozen in a refrigerator at -40°C for 2 h until the center temperature of the steamed buns reached -18°C.

[0118] (3) The steamed buns obtained in step (2) were stored at -18°C to obtain the finished product of the frozen raw steamed buns. The following indexes were determined periodically.

[0119] Textural indexes: the total texture parameters reflect the hardness and chewiness of the raw steamed buns (see Table 1);

[0120] Specific volume indexes: the volume change of the steamed buns during frozen storage (see Table 2);

[0121] Sensory indexes: appearance, color, internal structure, etc. (see Tables 3-5);

[0122] The frozen raw steamed buns prepared by Comparative Example 2 were stored at -18°C and placed for 1-2 weeks. After steaming, the skin of the steamed buns was shriveled and collapsed, the skin was yellow, the internal structure was rough, and the taste was hard, which reached an unacceptable state.

[0123] Comparative Example 3 (old dough)

[0124] The processing procedure of the frozen raw steamed buns includes the following steps:

[0125] (1) Preparation of the dough: 70 parts of flour, 52 parts of water, 1.2 parts of dry yeast, 4 parts of sugar, and 0.4 parts of salt were mixed to form a dough, leavened at 32°C for 12 h, and then placed in a kneading pot with 30 parts of flour and kneaded for 10 min to obtain a dough.

[0126] (2) Leavening and freezing of the steamed buns: the dough obtained in step (1) was leavened at 32°C and 85% RH for 2.5 h, then was rolled and degassed, divided into 50 g of sub-doughs, shaped, and then leavened at 32°C and 85% RH for 40 min. The steamed buns were then frozen in a refrigerator at -40°C for 2 h until the center temperature of the steamed buns reached -18°C.

[0127] (3) The steamed buns obtained in step (2) are stored at -18°C to obtain the frozen raw buns product. The following indexes are measured regularly.

[0128] Texture index: the whole texture parameters reflect the hardness, chewiness and other properties of the raw buns (see Table 1);

[0129] Specific volume index: the volume change of the buns during frozen storage (see Table 2);

[0130] Sensory index: appearance, color, internal structure, etc. (see Tables 3-5);

[0131] The frozen raw buns made by the present comparative example 3 are stored at -18°C, placed for 1-2 weeks, and after steaming, the skin is smooth, the skin is yellow, the internal structure is rough, and the taste is hard, which has reached an unacceptable state.

[0132] Comparative example 4 (old face yeast head)

[0133] The processing process of the frozen raw buns includes the following steps:

[0134] (1) Preparation of dough: 100 parts of flour, 52 parts of water, 5 parts of old face yeast head, 4 parts of sugar, 0.4 parts of salt, placed in a dough pot, and kneaded for 10 min to obtain dough.

[0135] (2) The dough obtained in step (1) is fermented at 32°C, 85% RH for 2.5h, then stretched and vented, divided into 50g of agent sub-bun molding, then fermented at 32°C, 85% RH for 40min. Put into-40°C refrigerator and freeze for 2h until the center temperature of the buns reaches-18°C.

[0136] (3) The steamed buns obtained in step (2) are stored at -18°C to obtain the frozen raw buns product. The following indexes are measured regularly.

[0137] Texture index: the whole texture parameters reflect the hardness, chewiness and other properties of the raw buns (see Table 1);

[0138] Specific volume index: the volume change of the buns during frozen storage (see Table 2);

[0139] Sensory index: appearance, color, internal structure, etc. (see Tables 3-5);

[0140] The frozen raw buns made by the present comparative example 1 are stored at -18°C, placed for 1-2 weeks, and after steaming, the skin is smooth, the skin is yellow, the internal structure is rough, and the taste is hard, which has reached an unacceptable state.

[0141] Comparative example 5

[0142] A method for improving the frozen raw buns frozen storage resistance, comprising the following steps:

[0143] (1) Preparation of rice wine: Take fresh glutinous rice 350g, wash and soak in water for 90 min, steam for 30 min, then cool down, when the temperature drops to about 30℃, mix in 0.2% sweet wine starter, then place in a constant temperature box at 30℃ for 48h fermentation.

[0144] (2) Preparation of rice wine fermented juice: Take 400 parts of rice wine, 600 parts of porridge (porridge weight is 1:2 mixed with steamed rice and water, cooked for 5 min), and 100 parts of bran from step (1), mix evenly and ferment at 25℃ for 15h. (The mass ratio of rice wine, porridge and bran is 4:6:1)

[0145] (3) Preparation of rice wine dough: 100 parts of flour, 61 parts of rice wine fermented juice obtained in step (2), 6 parts of sugar, and 0.4 parts of salt are placed in a dough mixer and mixed for 10 min to obtain rice wine dough.

[0146] (4) Baozi leavening and freezing: The rice wine dough obtained in step (3) is leavened at 32℃, 85% RH for 2.5h, then rolled out and degassed, divided into 50g portions, shaped, and then leavened at 32℃, 85% RH for 40 min. Then placed in a freezer at -40℃ for 2h until the center temperature of the baozi reaches -18℃.

[0147] (5) The baozi obtained in step (4) is stored at -18℃ to obtain the frozen raw baozi product. The following indicators are measured regularly.

[0148] Texture indicators: full texture parameters reflect the hardness, chewiness and other properties of raw baozi (see Table 1);

[0149] Specific volume indicators: volume change of baozi during frozen storage (see Table 2);

[0150] Sensory indicators: appearance, color, internal structure, etc. (see Tables 3-5);

[0151] The frozen raw baozi made by this comparative example 5 is stored at -18℃, placed for 1-2 weeks, and after steaming, the volume is small, the leavening degree is not enough, and the taste is hard, which has reached an unacceptable state.

[0152] Comparative Example 6

[0153] The rice wine fermented juice obtained in Comparative Example 5 has weak activity, and after fermentation, it is too thick, and the amount of squeezed rice wine fermented juice is insufficient to meet normal use.

[0154] (1) Preparation of rice wine: Take fresh glutinous rice 350g, wash and soak in water for 90 min, steam for 30 min, then cool down, when the temperature drops to about 30℃, mix in 0.2% sweet wine starter, then place in a constant temperature box at 30℃ for 48h fermentation.

[0155] (2) Preparation of wine lees juice: 400 parts of rice wine, 600 parts of porridge (porridge weight is cooked rice and water mixed at a ratio of 1:2 and cooked for 5 min), and 100 parts of bran in step (1) were weighed and mixed uniformly, and then fermented at 25°C for 15 h. (The mass ratio of rice wine, porridge, and bran was 4:6:1)

[0156] (3) Preparation of wine lees dough: 100 parts of flour, 54 parts of wine lees juice obtained in step (2), 4 parts of sugar, and 0.4 parts of salt were placed in a kneading pot for kneading. After 10 min, it was found that the dough could not be formed, which was insufficient for normal use.

[0157] In combination with Example 1 and Comparative Examples 5-6, it was found that the wine lees juice obtained from the formula of Comparative Example 5 was weak in vitality, and after fermentation, it was too thick, and the amount of wine lees juice squeezed out was too small, which was insufficient for normal use. On the other hand, by using the formula to prepare dough in a large amount, and then obtaining frozen raw buns, the frozen storage stability and texture effect of the frozen raw buns were not as good as those of the frozen raw buns obtained from the wine lees juice of the formula of Example 1.

[0158] The specific measurement results of each example and comparative example are shown in Tables 1-5.

[0159] Table 1 Change in texture quality of frozen raw buns prepared in each example and comparative example during frozen storage (unit: g)

[0160]

[0161] Table 2 Change in specific volume of frozen raw buns prepared in each example and comparative example during frozen storage (unit: mL / g)

[0162] fresh one week two weeks four weeks Example 1 1.99 1.85 1.78 1.70 Example 2 1.86 1.56 1.48 1.42 Example 3 1.81 1.59 1.52 1.47 Example 4 1.76 1.70 1.65 1.71 Example 5 2.12 1.75 1.71 1.58 Example 6 2.07 1.76 1.59 1.52 Example 7 2.03 1.79 1.70 1.67 Example 8 2.12 1.72 1.62 1.51 Comparative Example 1 1.74 1.42 1.25 1.24 Comparative Example 2 1.82 1.45 1.31 1.27 Comparative Example 3 1.93 1.54 1.49 1.28 Comparative Example 4 1.79 1.48 1.43 1.29 Comparative Example 5 1.45 1.28 1.27 /

[0163] Table 3 Sensory evaluation score of frozen raw buns prepared in each example and comparative example after frozen storage for 1 week

[0164]

[0165] Table 4 Sensory evaluation score of frozen raw buns prepared in each example and comparative example after frozen storage for 2 weeks

[0166]

[0167]

[0168] Table 5 Sensory evaluation score of frozen raw buns prepared in each example and comparative example after frozen storage for 4 weeks

[0169]

[0170] The above examples are not intended to limit the scope of the present application, nor are the described steps intended to limit the order in which they are performed. Modifications apparent to one skilled in the art in light of the above teachings are intended to fall within the scope of the claims.

Claims

1. A method for improving the frozen storage stability of raw steamed buns, characterized in that, The method involves mixing fermented rice wine juice with wheat flour, sugar, and salt to form a dough. This dough is then proofed, rolled, divided, and shaped to obtain raw buns. The raw buns are then proofed again and quick-frozen to obtain frozen raw buns. The fermented rice juice is prepared by the following method: Mix the yeast starter with steamed glutinous rice and water evenly, and incubate at a constant temperature to obtain rice wine; mix the obtained rice wine with porridge, bran, and water evenly, and ferment to obtain fermented rice wine juice; wherein, the fermentation raw materials for fermented rice wine juice are composed of the following weight parts: 250 parts rice wine, 75 parts porridge (based on dry rice), 30 parts bran, and 500 parts water; the mass ratio of dry rice to water used in the preparation of porridge is 1:5; According to the weight ratio, use 80-120 parts wheat flour, 50-56 parts fermented rice juice, 2-10 parts sugar, and 0.4-2 parts salt.

2. A method for preparing frozen raw buns that are stable during freezing, characterized in that, The method includes the following steps: (1) Preparation of rice wine: Add yeast, steamed glutinous rice and water, mix well, and place in a constant temperature incubator for a period of time to obtain rice wine; (2) Preparation of fermented rice wine juice: Add rice wine, porridge, bran and water, mix evenly, and place in a proofing box for a period of time to obtain fermented rice wine juice; wherein, rice wine 250 parts, porridge 75 parts based on dry rice, bran 30 parts and water 500 parts; the mass ratio of dry rice to water used in the preparation of porridge is 1:

5. (3) Preparation of mixed dough: Wheat flour, fermented rice wine juice, sugar and salt are placed in a mixing pot and stirred to obtain mixed dough for making buns; then the mixed dough is placed in a constant temperature and humidity proofing box to proof for a certain period of time; according to the weight ratio, wheat flour 80-120 parts, fermented rice wine juice 50-56 parts, sugar 2-10 parts, salt 0.4-2 parts; (4) Shaping raw buns: The fermented dough is rolled, divided, and wrapped into shape; (5) Proofing of raw buns: Place the shaped buns in a constant temperature and humidity proofing box, and then place the proofed buns in a quick-freezing freezer to freeze them, thus obtaining frozen raw buns.

3. The method according to any one of claims 1-2, characterized in that, In the preparation of the rice wine, the weight ratio of the raw materials, dried glutinous rice, water, and yeast is 700-1000 parts: 200-1200 parts: 4-8 parts.

4. The method according to any one of claims 1-2, characterized in that, In the preparation of the fermented rice wine juice, the fermentation time in the fermentation box is 8-24 hours, the temperature in the fermentation box is 25-38℃, and then it is raked at room temperature, 3-6 times within 1 hour.

5. The method according to any one of claims 1-2, characterized in that, The preparation of the mixed dough also includes: mixing a portion of wheat flour with other ingredients to obtain a preliminary dough product, then placing it in a constant temperature and humidity proofing box to proof for a certain period of time, and then adding another portion of wheat flour and kneading to obtain the final dough product.

6. The method according to any one of claims 1-2, characterized in that, In the preparation of the mixed dough, the temperature in the constant temperature and humidity chamber is 26-38℃, the humidity is 70-90% RH, and the fermentation time is 1-4 h. Fermentation is carried out in the constant temperature and humidity chamber; or it is refrigerated at 4℃ for 24 h.

7. A frozen raw bun product that is stable for freezing and prepared by the method according to any one of claims 1-6.

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