Rhizoma polygonati steamed sponge cake and preparation method thereof

Abstract

The invention relates to the technical field of fermented food, in particular to a polygonatum kingianum steamed sponge cake and a preparation method thereof. The invention provides a polygonatum kingianum steamed sponge cake which comprises the following components in parts by weight: 80-100 parts of fermented glutinous rice, 25-35 parts of polygonatum kingianum, 60-75 parts of polished round-grained rice and 10-20 parts of white granulated sugar. The fermented glutinous rice obtained through lactobacillus fermentation is used for preparing the polygonatum kingianum steamed sponge cake, the fermented glutinous rice obtained through lactobacillus fermentation can help to reduce pungent smell brought by polygonatum kingianum in the polygonatum kingianum steamed sponge cake, on the contrary, composite fragrance such as bouquet, mellow fragrance and fruit fragrance appears, meanwhile, the texture and the anti-aging performance of the polygonatum kingianum steamed sponge cake are improved, and the taste and the quality of the polygonatum kingianum steamed sponge cake are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fermented foods, and particularly relates to a polygonatum cake and a preparation method thereof. Background Art

[0002] Steamed cake is a traditional food made mainly from rice, widely distributed in large areas of the north and south. It has a delicate fragrance, rich nutrition, and is especially suitable for the elderly and children. The finished product has a white color like jade, fine pores like needles, a fragrant smell, a sweet but not greasy taste, and a glutinous but not sticky texture. Its biggest feature is that it is fermented with an appropriate amount of glutinous rice wine during the production process. However, the current steamed cakes have single flavors and textures, unable to meet the current needs of people.

[0003] Polygonati Rhizoma is the dried rhizome of a perennial herb of the genus Polygonatum Mill in the family Liliaceae. It was first recorded in the first pharmaceutical monograph in China, "Shennong Ben Cao Jing", and got its name because "it obtains the essence of the Kun soil". It is a traditional classic food and medicine dual-purpose plant and can replace food. Modern research shows that the rhizome of Polygonati Rhizoma does not contain starch, but is rich in non-starch polysaccharides, fructooligosaccharides, steroids, triterpenoid saponins, flavonoids and other nutritional and functional ingredients, and has the effects of invigorating qi, nourishing yin, strengthening the spleen, moistening the lungs, and tonifying the kidneys. Especially non-starch polysaccharides and fructooligosaccharides, like resistant starch, can also reduce postprandial blood sugar, and can regulate blood sugar and improve immunity by promoting insulin secretion and increasing insulin sensitivity. It is one of the most cost-effective dietary therapies for diabetic patients and the elderly. The unprocessed raw product of Polygonati Rhizoma contains volatile irritating components, which can directly contact the oral mucosa and induce pungent sensory characteristics, accompanied by low-dose toxic reactions, and need to be processed by a processing technology to reduce toxicity and increase efficacy. The traditional processing technology takes "nine steaming and nine boiling" as the core, and realizes the conversion of irritating components and the enrichment of sweet substances through repeated steaming and sun-drying treatments. However, this technology has multi-dimensional technical defects. The steaming and sun-drying process flow is complex, and the control difficulty of energy consumption and labor cost is significantly increased; the Maillard reaction proceeds excessively under high temperature conditions, and the final product is prone to sensory defects such as excessive browning, sticky texture, and excessive sweetness threshold; the lack of standardized process parameters leads to a large fluctuation range of active ingredients between different batches, seriously restricting its development potential as a functional food raw material. Based on the above characteristics of Polygonati Rhizoma, using Polygonati Rhizoma as an auxiliary ingredient in steamed cake can obtain a polygonatum cake with higher nutritional value and better health.

[0004] However, due to the pungent smell of Polygonati Rhizoma itself, and the addition of Polygonati Rhizoma will affect the fermentation of the steamed cake and the overall texture of the polygonatum cake. How to make the texture of the polygonatum cake better and meet the modern dietary requirements is a problem that needs to be considered. Summary of the Invention

[0005] The present invention aims to overcome the defect that the polygonatum cake in the prior art has the pungent smell of unprocessed polygonatum, and to promote fermentation and delay aging. Therefore, a polygonatum cake and its preparation method are provided to overcome the above defects.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a polygonatum cake, which comprises, by weight: 80 - 100 parts of fermented glutinous rice, 25 - 35 parts of polygonatum, 60 - 75 parts of japonica rice, and 10 - 20 parts of granulated sugar.

[0008] The fermented glutinous rice is obtained by fermenting with Lactiplantibacillus plantarum P-5; among them, Lactiplantibacillus plantarum P-5 is preserved in the China Center for Type Culture Collection, and the preservation number is CCTCC No: M 2025571.

[0009] In the polygonatum cake, the content of polygonatum powder is lower than that of the fermented glutinous rice. Therefore, the taste and quality of the finally prepared cake mainly depend on the quality of the fermented glutinous rice. When the quality of the fermented glutinous rice is too low, a cake with poor quality and taste is often obtained. The applicant unexpectedly found Lactiplantibacillus plantarum P-5, which can ferment to obtain fermented glutinous rice with higher quality; and the polygonatum cake prepared with this fermented glutinous rice greatly reduces the pungent smell brought by polygonatum in the polygonatum cake, and instead presents compound aromas such as wine aroma, mellow aroma, and fruity aroma. At the same time, the texture and anti-aging performance of the polygonatum cake are improved, greatly enhancing the taste and quality of the polygonatum cake.

[0010] Preferably, the Lactiplantibacillus plantarum P-5 is added in the form of a bacterial liquid with a Lactiplantibacillus plantarum P-5 content of 7.2 - 7.7 log CFU / mL.

[0011] More preferably, the Lactiplantibacillus plantarum P-5 is added in the form of a bacterial liquid with a Lactiplantibacillus plantarum P-5 content of 7.4 - 7.6 log CFU / mL.

[0012] More preferably, the Lactiplantibacillus plantarum P-5 is added in the form of a bacterial liquid with a Lactiplantibacillus plantarum P-5 content of 7.5 log CFU / mL.

[0013] The present invention provides a preparation method of a polygonatum cake, which comprises:

[0014] S1: After steaming and cooling glutinous rice, mix Lactiplantibacillus plantarum P-5, glutinous rice, sweet wine starter and water, and saccharify and ferment to obtain fermented glutinous rice; among them, Lactiplantibacillus plantarum P-5 is preserved in the China Center for Type Culture Collection, and the preservation number is CCTCC No: M 2025571;

[0015] S2: Mix the fermented glutinous rice obtained in S1 with polygonatum sibiricum, japonica rice, granulated sugar, and water, then perform primary fermentation, followed by secondary fermentation, and finally steam to obtain polygonatum sibiricum sponge cake.

[0016] Preferably, the Lactobacillus plantarum P-5 is added in the form of a bacterial liquid with a Lactobacillus plantarum P-5 content of 7.2 - 7.7 log CFU / mL.

[0017] More preferably, the Lactobacillus plantarum P-5 is added in the form of a bacterial liquid with a Lactobacillus plantarum P-5 content of 7.4 - 7.6 log CFU / mL.

[0018] Even more preferably, the Lactobacillus plantarum P-5 is added in the form of a bacterial liquid with a Lactobacillus plantarum P-5 content of 7.5 log CFU / mL.

[0019] Preferably, in S1, the mass ratio of the glutinous rice, sweet koji, and water is 100:(1 - 2):(80 - 150).

[0020] Preferably, in S1, the steaming time of the glutinous rice is at least 30 min, and the cooling is to make the temperature of the steamed glutinous rice reach 25 - 30 °C.

[0021] Preferably, in S1, the temperature of saccharification fermentation is 30 - 35 °C, and the time is 40 - 80 h.

[0022] Preferably, in S2, the temperature of primary fermentation is 30 - 35 °C, and the time is 1 - 2 h.

[0023] Preferably, in S2, the temperature of secondary fermentation is 50 - 60 °C, and the time is 5 - 15 min.

[0024] Preferably, in S2, the steaming time is at least 30 min.

[0025] Therefore, the present invention has the following beneficial effects:

[0026] (1) The present invention uses the fermented glutinous rice obtained by fermenting with Lactobacillus plantarum P-5 to prepare polygonatum sibiricum sponge cake. The fermented glutinous rice obtained by fermenting with Lactobacillus plantarum P-5 can help reduce the pungent smell brought by polygonatum sibiricum in the polygonatum sibiricum sponge cake, and instead, complex aromas such as wine aroma, mellow aroma, and fruity aroma appear. At the same time, it improves the texture and anti-aging performance of the polygonatum sibiricum sponge cake, greatly enhancing the taste and quality of the polygonatum sibiricum sponge cake.

[0027] (2) The method for assisting in preparing fermented glutinous rice provided by the present invention using Lactobacillus plantarum P-5 can be used to improve the quality of fermented glutinous rice made into sponge cake with medium or low quality, maximizing the value of the fermented glutinous rice.

[0028] (3) The yellow - refined rice cake provided by the present invention has a reduced overall starch hydrolysis rate after the introduction of Lactobacillus plantarum P - 5, and its anti - digestion performance is superior to that of ordinary rice cakes.

[0029] (4) The present invention uses Lactobacillus plantarum P - 5 to promote the proliferation of yeast cells during the fermentation of yellow - refined rice cakes, enhances the gas - producing ability of rice milk, exhibits better swelling characteristics, and the obtained yellow - refined rice cakes are fluffy and soft. Description of the Drawings

[0030] Figure 1 It is a diagram showing the effect of different lactic acid bacteria strains on the number of Saccharomyces cerevisiae colonies in fermented glutinous rice;

[0031] Figure 2 It is a diagram showing the effect of different dosages of lactic acid bacteria on the number of Saccharomyces cerevisiae colonies in fermented glutinous rice;

[0032] Figure 3 It is an XRD diagram;

[0033] Figure 4 It is an SEM diagram of Comparative Example 1;

[0034] Figure 5 It is an SEM diagram of Comparative Example 2;

[0035] Figure 6 It is an SEM diagram of Example 1;

[0036] Figure 7 It is the result of starch hydrolysis rate;

[0037] Figure 8 It is a physical photo of the rice cake. Detailed Embodiments

[0038] The following further describes the present invention with specific embodiments. Those of ordinary skill in the art will be able to implement the present invention based on these descriptions. In addition, the embodiments of the present invention described below are generally only a part of the embodiments of the present invention, rather than all of the embodiments. Therefore, all other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments of the present invention shall fall within the scope of protection of the present invention.

[0039] In this part, glutinous rice was purchased from Heliang Agriculture Co., Ltd. (protein: 7.2%; fat: 0.7%; carbohydrates: 77%); polished round - grained rice flour was purchased from Shennong Food Co., Ltd. (protein: 8.5%; fat: 1.1%; carbohydrates: 78.1%); granulated sugar was purchased from Yiwu Tiankun Food Factory; yellow - refined slices were purchased from Yipu Yuan Huangjing Technology Co., Ltd., Xinhua County, China.

[0040]

Preparation before Experiment

[0041] 1. Preparation of raw yellow - refined whole powder

[0042] The dried raw polygonatum slices (water content: 10.3%) are pulverized and passed through a 60-mesh sieve, and then stored in a cool and dry place.

[0043] 2. Preparation of glutinous rice

[0044] Select glutinous rice with better quality, uniform appearance and complete form, and perform operations such as washing, soaking, rinsing, and draining. After the treatment is completed, it is reserved for use.

[0045] 3. Lactobacillus

[0046] Lactiplantibacillus plantarum P-5 is isolated and extracted in the laboratory.

[0047] Lactiplantibacillus plantarum P-5 is deposited in the China Center for Type Culture Collection, with the deposit number CCTCC M 2025571 and the deposit date of March 24, 2025.

[0048]

Pre-experiment screening

[0049] Experiment 1

[0050] After the pot is steaming, 100 g of glutinous rice is steamed for 30 min until the rice grains are brittle and have no white core. The steamed glutinous rice is placed in a flat mold and cooled to 25°C - 30°C. 1.2 g of sweet koji, 1.2% Lactiplantibacillus plantarum P-5 (bacterial content about 7.5 log CFU / mL) and 100 g of distilled water are added to the cooled glutinous rice and mixed evenly. After the koji is evenly mixed, it is filled into a sterilized fermentation bottle. A nest is dug in the center of the compacted raw materials, covered, and placed in a constant temperature incubator at 34°C for sealed saccharification fermentation for 48 h to obtain fermented glutinous rice.

[0051] Experiment 2

[0052] This experiment is basically the same as Experiment 1, except that: Lactiplantibacillus plantarum P-5 is replaced with Lactiplantibacillus plantarum Z-2 with the same bacterial content (deposited in the China Center for Type Culture Collection, deposit number CCTCC LB 2008168).

[0053] Experiment 3

[0054] This experiment is basically the same as Experiment 1, except that: Lactiplantibacillus plantarum P-5 is replaced with Lactobacillus pentosus P-7 with the same bacterial content (deposited in the China Center for Industrial Culture Collection of Microorganisms, deposit number CICC 21798).

[0055] Experiment 4

[0056] This experiment is basically the same as Experiment 1, except that: Lactiplantibacillus plantarum P-5 is replaced with Lactobacillus buchneri 28-1 with the same bacterial content.

[0057] Experiment 5

[0058] This experiment is basically the same as Experiment 1, except that: 1.2% Lactobacillus plantarum P-5 is replaced by 0.6% Lactobacillus plantarum P-5 (bacterial content is about 7.3 log CFU / mL).

[0059] Experiment 6

[0060] This experiment is basically the same as Experiment 1, except that: 1.2% Lactobacillus plantarum P-5 is replaced by 1.8% Lactobacillus plantarum P-5 (bacterial content is about 7.8 log CFU / mL).

[0061] Experiment 7

[0062] This experiment is basically the same as Experiment 1, except that: the addition of Lactobacillus plantarum P-5 is cancelled, denoted as control.

[0063] 1. Counting the total number of yeast colonies in fermented glutinous rice wine (screening out the most suitable lactic acid bacteria strain to promote yeast growth)

[0064] Perform yeast colony counting on the fermented glutinous rice wine obtained in Experiments 1-4 and 7, and the results are as Figure 1 shown. It can be observed that only the addition of Lactobacillus plantarum P-5 in Experimental Group 1 helps to increase the total number of yeast colonies in fermented glutinous rice wine.

[0065] 2. Determination of the total number of yeast colonies in fermented glutinous rice wine (proportion of lactic acid bacteria)

[0066] Perform yeast colony counting on the fermented glutinous rice wine obtained in Experiments 1, 5-7, and the results are as Figure 2 shown. It can be observed Figure 2 that the addition of Lactobacillus plantarum P-5 all helps to increase the total number of yeast colonies in fermented glutinous rice wine, but the addition of 1.2% Lactobacillus plantarum P-5 is the most beneficial for increasing the total number of yeast colonies in fermented glutinous rice wine.

[0067] 3. pH and sugar content

[0068] Measure the pH and sugar content of the fermented glutinous rice wine obtained in Experiments 1-7, and the results are shown in Table 1. Observing Table 1, it can be seen that the addition of lactic acid bacteria will cause changes in the pH and sugar content of fermented glutinous rice wine. The pH of Experimental Group 1 has a significant difference from other groups, and there is no significant difference in sugar content.

[0069] Table 1 Effects of lactic acid bacteria on pH and sugar content of fermented glutinous rice wine

[0070]

[0071] Note: Different letters in the same column indicate significant data differences (P<0.05).

[0072]

Example

[0073] Example 1

[0074] S1. After the pot is steaming, steam 100 g of glutinous rice for 30 min until the rice grains are fragile and have no white core. Put the steamed glutinous rice into a flat mold and let it cool to 25 - 30 °C. Add 1.2 g of sweet yeast, 1.2% Lactobacillus plantarum P - 5, and 100 g of distilled water to the cooled glutinous rice and mix well. After mixing the yeast evenly, put it into a sterilized fermentation bottle, make a hole in the center of the compacted raw materials, seal the lid, and place it in a constant temperature incubator at 34 °C for sealed saccharification fermentation for 48 h to obtain fermented glutinous rice wine.

[0075] S2. Weigh 71 g of japonica rice flour, 29 g of polygonatum sibiricum powder, 90 g of fermented glutinous rice wine, 14 g of granulated sugar, and 70 g of water, and mix and grind them evenly into a slurry. Place the evenly mixed raw and auxiliary material mixture in a fermentation box at 34 °C for fermentation for 1.5 h. After fermentation is completed, take it out, stir it thoroughly to exhaust the gas, and then place the raw and auxiliary materials in a steamer at 60 °C for medium - temperature short - time fermentation for 10 min. After fermentation ends, turn on the fire and steam for 30 min until it is cooked. Take out the steamed fermented glutinous rice wine cake, cool it to room temperature, and then demold it to obtain the finished product.

[0076] Comparative Example 1 (without polygonatum sibiricum powder and lactic acid bacteria)

[0077] S1. After the pot is steaming, steam 100 g of glutinous rice for 30 min until the rice grains are fragile and have no white core. Put the steamed glutinous rice into a flat mold and let it cool to 25 - 30 °C. Add 1.2 g of sweet yeast and 100 g of distilled water to the cooled glutinous rice and mix well. After mixing the yeast evenly, put it into a sterilized fermentation bottle, make a hole in the center of the compacted raw materials, seal the lid, and place it in a constant temperature incubator at 34 °C for sealed saccharification fermentation for 48 h to obtain fermented glutinous rice wine.

[0078] S2. Weigh 100 g of japonica rice flour, 90 g of fermented glutinous rice wine, 14 g of granulated sugar, and 70 g of water, and mix and grind them evenly into a slurry. Place the evenly mixed raw and auxiliary material mixture in a fermentation box at 34 °C for fermentation for 1.5 h. After fermentation is completed, take it out, stir it thoroughly to exhaust the gas, and then place the raw and auxiliary materials in a steamer at 60 °C for medium - temperature short - time fermentation for 10 min. After fermentation ends, turn on the fire and steam for 30 min until it is cooked. Take out the steamed fermented glutinous rice wine cake, cool it to room temperature, and then demold it to obtain the finished product.

[0079] Comparative Example 2 (without Lactobacillus plantarum P - 5)

[0080] This comparative example is basically the same as Example 1, and the difference is that in step S1, the addition of 1.2% Lactobacillus plantarum P - 5 at 7.5 log CFU / mL is cancelled.

[0081] Comparative Example 3

[0082] This comparative example is basically the same as Example 1, except that: in step S1, Lactobacillus plantarum P-5 is replaced with Lactobacillus plantarum Z-2 with the same bacterial content.

[0083] Comparative Example 4

[0084] This comparative example is basically the same as Example 1, except that: in step S1, Lactobacillus plantarum P-5 is replaced with Lactobacillus pentosus P-7 with the same bacterial content.

[0085] Comparative Example 5

[0086] This comparative example is basically the same as Example 1, except that: in step S1, Lactobacillus plantarum P-5 is replaced with Lactobacillus buchneri 28-1 with the same bacterial content.

[0087]

Performance Test

[0088] 1. Volatile Flavor Components

[0089] The volatile flavor components of the polygonatum cake obtained in Example 1 and Comparative Examples 1-5 were determined. The results are shown in Tables 2-9 below. The addition of Lactobacillus plantarum P-5 reduced the pungent odors rich in raw polygonatum in the cake, such as volatile components like hexanal, pentanol, trans-2-octenal, 1-octen-3-ol, and 3-aminophenylacetylene, and increased the volatile components with a faint fruity aroma such as nonanol, (2R,3R)-(-)-2,3-butanediol, ethyl acetate, γ-nonalactone, and ethyl cinnamate. These compounds together constitute the rich flavors of the cake, such as wine aroma, mellow aroma, and fruity aroma, making the cake have a rich taste and a strong texture, and improving the sensory quality of the cake to a certain extent.

[0090] Table 2 Comparison Table of Volatile Components of Positive Flavors

[0091] Nonanol / % (2R,3R)-(-)-2,3-Butanediol / % Ethyl acetate / % γ-Nonalactone / % Ethyl cinnamate / % Example 1 0.10 0.12 0.06 0.12 0.10 Comparative Example 1 / / / / / Comparative Example 2 / / / / / Comparative Example 3 0.03 0.05 / / 0.02 Comparative Example 4 / / / 0.02 0.03 Comparative Example 5 / / / 0.05 /

[0092] Table 3 Comparison Table of Volatile Components of Bad Flavors

[0093] n-Hexanal / % Pentanol / % trans-2-Octenal / % 1-Octen-3-ol / % 3-Aminophenylacetylene / % Example 1 / 0.45 0.01 / / Comparative Example 1 0.02 / 0.06 / 0.02 Comparative Example 2 0.34 1.37 0.12 0.20 0.05 Comparative Example 3 0.24 1.12 0.04 0.07 0.03 Comparative Example 4 0.17 1.17 0.07 0.14 0.06 Comparative Example 5 0.28 1.91 0.10 0.05 0.03

[0094] Table 4 Flavor Components of the Polygonatum Cake Obtained in Example 1

[0095]

[0096]

[0097]

[0098] Table 5 Flavor Components of the Polygonatum Cake Obtained in Comparative Example 1

[0099]

[0100]

[0101] Table 6 Flavor components of the polygonatum sponge cake obtained in Comparative Example 2

[0102]

[0103]

[0104]

[0105] Table 7 Flavor components of the polygonatum sponge cake obtained in Comparative Example 3

[0106]

[0107]

[0108] Table 8 Flavor components of the polygonatum sponge cake obtained in Comparative Example 4

[0109]

[0110]

[0111] Table 9 Flavor components of the polygonatum sponge cake obtained in Comparative Example 5

[0112]

[0113]

[0114] 2. Specific volume and height-diameter ratio

[0115] As can be seen from the data in Table 10 and Figure 8 the specific volume of the sponge cake in the example was 1.31 mL / g, and the height-diameter ratio was 0.40, which was significantly better than that of the sponge cake in Comparative Example 2 (p < 0.05), being 20.18% and 17.65% higher respectively. Thus, Lactobacillus plantarum P-5 promoted the proliferation of yeast cells, enhanced the gas production capacity of the rice slurry, and showed better expansion characteristics.

[0116] Table 10 Effects of polygonatum on the specific volume and height-diameter ratio of sponge cake

[0117]

[0118] Note: Different letters in the same column indicate significant differences in data (p < 0.05).

[0119] 3. Texture properties

[0120] The texture properties of the polygonatum sponge cakes obtained in Example 1 and Comparative Examples 1-5 were tested, and the results are shown in Table 11. From the results in Table 11, it can be seen that compared with Comparative Example 2, after adding lactic acid bacteria, the adhesiveness and chewiness of the polygonatum sponge cake increased significantly. Among them, the increase effect of Lactobacillus plantarum P-5 was the most significant, proving that the polygonatum sponge cake fermented with the wine brewed by Lactobacillus plantarum P-5 has excellent texture properties, and the fermented glutinous rice wine prepared by Lactobacillus plantarum P-5 can improve the quality of the polygonatum sponge cake. The sponge cake in the example shows moderate energy dissipation characteristics during chewing through the synergistic fermentation of polygonatum and Lactobacillus plantarum P-5 with yeast, which not only avoids jaw fatigue caused by being too hard but also prevents deterioration of the taste caused by being too sticky, which is in good agreement with the ideal quality of the sponge cake.

[0121] Table 11 Texture properties

[0122]

[0123]

[0124] Note: Different letters in the same column indicate significant data differences (p < 0.05).

[0125] 4. Aging hardness

[0126] The texture properties of the polygonatum sponge cakes or ordinary sponge cakes prepared in Example 1 and Comparative Examples 1-2 were tested after being stored at 25°C for 0 days and 4 days, and the results are shown in Table 12. It can be seen that after 4 days of storage, the aging rate of the polygonatum sponge cake fermented by Lactobacillus plantarum P-5 in synergy with yeast decreased significantly.

[0127] Table 12 Effect of polygonatum on the hardness (N) of sponge cake under the condition of 25°C

[0128]

[0129] 5. XRD crystal structure

[0130] The XRD tests were carried out on the polygonatum sponge cakes or ordinary sponge cakes prepared in Example 1 and Comparative Examples 1-2 after being stored for 4 days, and the results are as Figure 3 shown. It can be seen that after adding Lactobacillus plantarum P-5 in synergy with yeast for fermentation, the relative crystallinity of the polygonatum sponge cake decreased significantly, which has a certain delaying effect on the recrystallization of starch molecules and can improve the storage stability of the sponge cake.

[0131] 6. Fourier short-range ordered structure

[0132] The Fourier short-range ordered structure test was carried out on the polygonatum rice cakes or ordinary rice cakes prepared in Example 1 and Comparative Examples 1-2 after storage for 4 days, and the results are shown in Table 13. It can be seen from the results in the table that after fermentation with Lactobacillus plantarum P-5 in combination with yeast, the short-range ordered structure of the polygonatum rice cake was significantly reduced, which means that the short-range ordering process of the starch molecular chain during storage was inhibited, and the starch aging of the rice cake was delayed.

[0133] Table 13 Short-range ordered structure of rice cakes stored for 4 days

[0134]

[0135] 7. Microstructure

[0136] The scanning electron microscope test was carried out on the polygonatum rice cakes or ordinary rice cakes prepared in Example 1 and Comparative Examples 1-2, and the results are as Figures 4 - 6 shown. It can be observed that Figure 6 the surface of the polygonatum rice cake fermented with Lactobacillus plantarum P-5 in combination with yeast is denser and smoother, promoting the formation of a denser layered structure of the gel network, effectively restricting the migration and rearrangement of starch granules.

[0137] 8. Starch hydrolysis rate and eGI value

[0138] The starch hydrolysis rate test was carried out on the polygonatum rice cakes or ordinary rice cakes prepared in Example 1 and Comparative Examples 1-2, and the results are as Figure 7 shown in the figure and Table 14. It can be seen from the results in the figure that after fermentation with Lactobacillus plantarum P-5 in combination with yeast, the starch hydrolysis rate of the polygonatum rice cake increased slowly, the content of resistant starch (RS) increased significantly, and the eGI value decreased significantly, which is suitable for people with unstable blood sugar to eat.

[0139] Table 14 Effects of polygonatum on the starch composition and eGI value of rice cakes

[0140]

[0141] Note: Different letters in the same column indicate significant differences in data (p<0.05).

Claims

1. A polygonatum cake, characterized in that, By weight, it includes: 80 to 100 parts of fermented glutinous rice, 25 to 35 parts of polygonatum, 60 to 75 parts of polished rice, and 10 to 20 parts of granulated sugar; The fermented glutinous rice is obtained by fermenting with Lactiplantibacillus plantarum P-5; among them, Lactiplantibacillus plantarum P-5 is preserved in the China Center for Type Culture Collection, and the preservation number is CCTCC No: M 2025571.

2. The polygonatum cake according to claim 1, characterized in that The Lactiplantibacillus plantarum P-5 is added in the form of a bacterial liquid with a Lactiplantibacillus plantarum P-5 content of 7.2 to 7.7 log CFU / mL.

3. A preparation method of polygonatum cake, characterized in that, It includes: S1: After steaming and cooling glutinous rice, mix Lactiplantibacillus plantarum P-5, glutinous rice, sweet yeast starter and water, and saccharify and ferment to obtain fermented glutinous rice; among them, Lactiplantibacillus plantarum P-5 is preserved in the China Center for Type Culture Collection, and the preservation number is CCTCC No: M 2025571; S2: Mix the fermented glutinous rice obtained in S1 with polygonatum, polished rice, granulated sugar and water, ferment once, then ferment twice, and steam to obtain polygonatum sponge cake.

4. The preparation method according to claim 3, characterized in that, In S1, the Lactiplantibacillus plantarum P-5 is added in the form of a bacterial liquid with a Lactiplantibacillus plantarum P-5 content of 7.2 to 7.7 log CFU / mL.

5. The preparation method according to claim 3 or 4, characterized in that In S1, the mass ratio among the glutinous rice, sweet yeast starter and water is 100:(1 to 2):(80 to 150).

6. The preparation method according to claim 3, characterized in that, In S1, the steaming time of the glutinous rice is at least 30 min, and the cooling is to make the temperature of the steamed glutinous rice reach 25 to 30 °C.

7. The preparation method according to claim 3, characterized in that, In S1, the temperature of the saccharification and fermentation is 30 to 35 °C, and the time is 40 to 80 h.

8. The preparation method according to claim 3, characterized in that, In S2, the temperature of the first fermentation is 30 to 35 °C, and the time is 1 to 2 h.

9. The preparation method according to claim 3 or 8, characterized in that, In S2, the temperature of the second fermentation is 50 to 60 °C, and the time is 5 to 15 min.

10. The preparation method according to claim 3, characterized in that, In S2, the steaming time is at least 30 min.

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