Preparation method of fingered citron monascus fermented composition

Abstract

The invention relates to the field of biological fermentation, and discloses a preparation method of a fingered citron monascus fermentation composition, which comprises the following steps: 1) removing essential oil components in fingered citron in a drying mode; (2) preparing the fingered citron obtained in the step (1) and rice into powder; (3) mixing fingered citron powder, rice flour and water to prepare a solid-state fermentation substrate; 4, the monascus is inoculated into the solid-state fermentation substrate for fermentation, and the fermentation product is the fingered citron and monascus fermented composition.The monascus is used for solid-state fermentation with fingered citron and rice flour as raw materials for the first time, it is found that fingered citron can promote and increase the content of effective components including polysaccharide, Monacolin K, flavone and the like in the fermentation product, and therefore the effect of the fingered citron and monascus fermented composition is improved.

Description

Technical Field

[0001] The present invention relates to the field of biological fermentation, and particularly to a preparation method of a bergamot red yeast rice fermentation composition. Background Art

[0002] Bergamot has the effects of relieving cough, reducing phlegm, lowering blood lipid, anti-tumor, antioxidant, immune regulation, antibacterial and anti-inflammatory. At present, the research on bergamot mainly focuses on the extraction of active ingredients and the deep processing of bergamot products. The extraction of active ingredients mainly focuses on the extraction of essential oils, polysaccharides and flavonoids. The deep processing methods of bergamot are mainly in two aspects. One is the drying method, such as the traditional drying method in the Chinese Pharmacopoeia. The primary processing method of bergamot is to harvest the fruits in autumn before they turn yellow or when they turn yellow, cut them longitudinally into thin slices, and dry them in the sun or at low temperature. Modern methods have made some improvements in the drying method, such as hot air drying, freeze drying, microwave drying, vacuum freeze drying, etc. On the other hand, it is mainly to process bergamot into food such as bergamot candied fruit, bergamot preserved fruit, bergamot wine, etc. Bergamot contains a variety of pharmacodynamic active ingredients, which have the effects of improving the immune function of the body, lowering blood lipid, anti-tumor, etc. With the in-depth study of its bioactive substances, developing functional foods, health foods or even traditional Chinese patent medicines with bergamot as the raw material is a development path with broad prospects.

[0003] Red yeast rice is both a traditional Chinese medicine and a food, which is a fermentation product cultivated by microorganisms such as Monascus using grains as raw materials. At present, people have carried out extensive and in-depth research on the metabolites of Monascus. The main secondary metabolites produced by Monascus include: (1) Monascus pigments: safe and non-toxic, and also have some special functions such as antibacterial and antioxidant; (2) Monacolin K: has the function of inhibiting cholesterol synthesis; (3) γ-aminobutyric acid: has physiological functions such as lowering blood pressure, sedation, hypnotic and anti-convulsant, increasing cerebral blood flow, and improving brain vitality; (4) Blood sugar regulating substances: Monascus can produce various enzymes during the growth process, such as amylase, glucoamylase, protease, pectinase, etc. Cao Huiyun et al. found through clinical observation and comparative experiments that it has the function of regulating blood sugar; (5) Monascus polysaccharides: have the effect of regulating immunity; (6) Flavonoids and dimer acids: effective antioxidant substances, with strong free radical scavenging ability.

[0004] In summary, both bergamot and red yeast rice, as common traditional Chinese medicines, have the effects of antibacterial, lowering blood lipid, and enhancing immunity. At present, there have been many reports on preparing various health products by compounding bergamot and red yeast rice. For example, Patent CN117814433A discloses a diet therapy formula for adapting to the rehabilitation of cardiovascular and cerebrovascular diseases, nourishing the liver and kidneys, and enhancing immunity, which contains bergamot and red yeast rice. However, at present, there is no report on solid-state fermentation using Monascus with bergamot as the raw material. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a method for preparing a bergamot red yeast rice fermentation composition. The present invention for the first time uses Monascus to perform solid-state fermentation with bergamot and rice flour as raw materials, and finds that bergamot can promote the increase of the contents of effective components such as polysaccharides, Monacolin K, and flavonoids in the fermentation products, thereby improving the efficacy of the bergamot red yeast rice composition.

[0006] The specific technical solution of the present invention is as follows: A method for preparing a bergamot red yeast rice fermentation composition, which includes the following steps: 1) Remove the essential oil components from the bergamot.

[0007] 2) Make the bergamot obtained in 1) and rice into powder.

[0008] 3) Mix the bergamot powder, rice flour and water to obtain a solid-state fermentation substrate.

[0009] 4) Inoculate Monascus into the solid-state fermentation substrate for fermentation, and the fermentation product is the bergamot red yeast rice fermentation composition.

[0010] The present invention for the first time biologically and organically combines two superior traditional Chinese medicine products, namely traditional Chinese medicine bergamot and red yeast rice. It is found that when Monascus performs solid-state fermentation on a mixture of rice and bergamot, bergamot can promote Monascus to produce Monacolin K, and flavonoids can also promote the production of red yeast rice polysaccharides. Therefore, the present invention can increase the contents of effective components such as polysaccharides, Monacolin K, and flavonoids in the product, which can regulate immunity and reduce blood lipids, and improve the added value of bergamot and red yeast rice products.

[0011] For example, it can be produced as a traditional Chinese medicine decoction piece, or as a koji for producing medicinal wine with blood lipid-lowering and antioxidant functions.

[0012] Furthermore, the present invention also accidentally discovers that if the unpretreated bergamot powder is directly made into a solid-state fermentation substrate with rice flour and water and then inoculated with Monascus, it will have an inhibitory effect on Monascus. After analysis, the reason may be that the essential oil components in bergamot have a certain inhibitory effect on Monascus. Therefore, the present invention specifically pre-removes the essential oil components from the bergamot to effectively solve the above technical problems.

[0013] Preferably, in step 1), the essential oil components are removed by a drying method, and the drying method is one or a combination of more of drying in an oven, natural sun drying, drying in the shade, and microwave drying.

[0014] More preferably, in step 1), the temperature for drying in the oven is 40-50°C; most preferably 45°C.

[0015] The present invention finds that when adopting the drying method, different drying temperatures have little influence on the production of Monacolin K and the polysaccharide content by Monascus, but have a relatively greater influence on the total flavonoid content. When the drying temperature is below 50°C, the influence on the flavonoid content is little, while when it is above 50°C, the flavonoid content will decrease significantly, which may be due to a small amount of destruction of flavonoids in the bergamot at high temperatures. Therefore, a drying temperature below 50°C is more appropriate.

[0016] Preferably, in step 2), the rice is indica rice.

[0017] Preferably, in step 3), the mass ratio of the bergamot powder to the rice powder is 1:3 - 1:2; most preferably 1:3.

[0018] The present invention finds that when the ratio of bergamot to indica rice is relatively high, the growth of Monascus will be restricted. After slow growth, the water generated during growth will decrease, causing the culture medium to dry out, resulting in insufficient water in the later stage and the growth of Monascus stopping. When the ratio of bergamot to indica rice is reduced to below 1:2, this inhibitory phenomenon is not obvious, the growth of Monascus proceeds normally, the culture medium will not dry out, and the growth will not stop. When the ratio continues to drop to below 1:3, the growth rate slows down significantly, and at the same time, the total flavonoid content decreases significantly. Since the growth will stop when the ratio of bergamot to indica rice is relatively high, Monascus produces less polysaccharide, resulting in a relatively low polysaccharide content. Therefore, the optimal ratio is 1:3.

[0019] Preferably, in step 3), the water content of the solid fermentation substrate is 30 - 40 wt%; most preferably 35 wt%.

[0020] The present invention finds that the growth of Monascus changes greatly in solid fermentation substrates with different water contents. When the water content is low, the growth of Monascus is slow or even stops. When the water content is above 30%, the growth of Monascus is good. When the water content exceeds 40%, since the solid is in a paste state, it is not conducive to the transfer of oxygen and mass transfer is difficult, which is not conducive to the formation of secondary metabolites, so the content of Monacolin K decreases. Therefore, the optimal water content is 35%.

[0021] Preferably, in step 4), the Monascus includes one or more of Monascus purpureus, Monascus anka, Monascus pilosus, and Monascus ruber. Further preferably, it includes one or more of Monascus GM011, Monascus GM01, and Monascus GM02; most preferably Monascus GM011.

[0022] The present invention discovers that during the same fermentation process, Monacolin K content of Monascus GM011 is the highest, total flavonoid content shows little change compared with other strains, while polysaccharide content decreases as Monacolin K content increases. This may be because strains with high Monacolin K content have higher product conversion rate and more thorough sugar consumption. Considering comprehensively, strain GM011 is most preferably selected.

[0023] Preferably, in step 4), the inoculation amount of the Monascus is 15 - 30%; more preferably 20 - 25%; most preferably 20%.

[0024] The present invention discovers that the inoculation amount of Monascus has a great influence on the content of active ingredients in the fermentation product. When the inoculation amount is low, the growth state of Monascus is poor, the produced Monacolin K content is low, and at the same time the flavonoid content is relatively high. As the inoculation amount increases, the Monacolin K content increases rapidly. When the inoculation amount reaches 20% or more, the Monacolin K content decreases instead. This is because after the inoculation amount reaches a certain level, the corresponding increase in water content makes the whole material more viscous, affecting the oxygen absorption, nutrient transfer and product formation of the material. Since the natural flavonoids in the Buddha's hand are not affected by the growth of Monascus when the inoculation amount is low, the flavonoid content is relatively high, and it decreases after the inoculation amount increases. The content no longer decreases after the inoculation amount reaches 15%, which may be because the natural flavonoids are no longer affected and flavonoids are formed during the growth of Monascus. The polysaccharide content is also low when the inoculation amount is low, indicating that Monascus does not grow to produce Monascus polysaccharide. After the inoculation amount reaches 20% with the growth, the polysaccharide content no longer increases but decreases instead. This may be related to more decomposition of the polysaccharide in the Buddha's hand and less production of Monascus polysaccharide. Based on the above phenomena, the optimal inoculation amount is 20%.

[0025] Preferably, in step 4), the fermentation conditions are: temperature 20 - 35°C, pH 3 - 7, time not less than 30 days; more preferably, the fermentation conditions are: temperature 24 - 26°C, pH = 4 - 6, time 30 - 40 days; most preferably, the fermentation conditions are: temperature 25°C, pH = 6, time 30 days.

[0026] Preferably, in step 4), before the Monascus is inoculated into the solid fermentation substrate, it is sequentially subjected to slant culture and liquid culture.

[0027] More preferably, the slant culture includes: transferring the refrigerated Monascus to a slant medium, culturing at 25 - 35°C for 5 - 10 days; then transferring to another slant medium, culturing at 25 - 35°C for 5 - 10 days, and adding sterile water to control the spore amount at 5×10 4 ~2×10 5CFU / mL. Further preferably, the liquid culture comprises: transferring the bacterial liquid obtained from the slant culture to the seed culture medium at an inoculation amount of 15-25%, and culturing at 100-300 rpm and 25-35 °C for 2-4 days to obtain the seed liquid.

[0028] Further preferably, the seed culture medium comprises: 3-7 wt% glucose, 0.5-2 wt% peptone, 0.5-2 wt% yeast powder, 0.1-1 wt% KH2PO4, 0.1-1 wt% MgSO4, 0.5-2 wt% rice flour.

[0029] Preferably, in step 4), the fermentation product is subjected to a drying treatment.

[0030] Preferably, in the fermented product of bergamot and Monascus, the content of Monacolin K is ≥ 8 mg / g, the total flavonoid content is ≥ 11 mg / g, and the polysaccharide content is ≥ 28 mg / g.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The present invention combines bergamot and Monascus organically for the first time, and it is found that when Monascus is subjected to solid-state fermentation on a mixture of rice and bergamot, bergamot can promote Monascus to produce Monacolin K, and flavonoids can also promote the production of Monascus polysaccharides. Therefore, the present invention can increase the content of effective components such as polysaccharides, Monacolin K, and flavonoids in the product, which can regulate immunity and reduce blood lipid, and improve the added value of bergamot and Monascus products.

[0032] (2) The present invention pre-removes the essential oil components in bergamot to avoid the inhibitory effect of the essential oil components on Monascus during the solid-state fermentation process, thereby further increasing the content of each active ingredient in the fermentation product.

[0033] (3) By further optimizing the proportion of raw materials of the solid-state fermentation matrix, the Monascus strain, and the solid-state fermentation process, etc., the present invention can further increase the content of active ingredients such as polysaccharides, Monacolin K, and flavonoids in the fermentation product. Description of the Drawings

[0034] Figure 1 Shows the influence of different inoculation amounts of Monascus on the content of active ingredients in the fermentation product.

[0035] Figure 2 Shows the influence of different fermentation temperatures on the content of active ingredients in the fermentation product.

[0036] Figure 3 Shows the influence of different fermentation pH values on the content of active ingredients in the fermentation product.

[0037] Figure 4The influence of different fermentation times on the content of active ingredients in the fermentation products. Detailed implementation mode

[0038] The present invention will be further described below in conjunction with embodiments.

[0039] General embodiment A preparation method of a bergamot red yeast rice fermentation composition, which comprises the following steps: 1) Remove the essential oil components in the bergamot by a drying method.

[0040] In some preferred embodiments, in step 1), the drying method is one or a combination of drying, natural sun drying, drying in the shade, and microwave drying.

[0041] In some more preferred embodiments, in step 1), the drying temperature is 40-50°C; most preferably 45°C.

[0042] 2) Make the bergamot obtained in step 1) and rice into powder.

[0043] In some preferred embodiments, in step 2), the rice is indica rice.

[0044] 3) Mix the bergamot powder, rice powder and water to obtain a solid fermentation substrate.

[0045] In some preferred embodiments, in step 3), the mass ratio of the bergamot powder to the rice powder is 1:3-1:2; most preferably 1:3.

[0046] In some preferred embodiments, in step 3), the moisture content of the solid fermentation substrate is 30-40 wt%; most preferably 35 wt%.

[0047] 4) Inoculate Monascus bacteria into the solid fermentation substrate for fermentation, and the fermentation product is the bergamot red yeast rice fermentation composition.

[0048] In some preferred embodiments, in step 4), the Monascus bacteria include one or more of Monascus purpureus, Monascus anka, Monascus pilosus, and Monascus ruber. Further preferably, it includes one or more of Monascus GM011, Monascus GM01, and Monascus GM02; most preferably Monascus GM011.

[0049] In some preferred embodiments, in step 4), the inoculation amount of the Monascus bacteria is 15-30%; further preferably 20-25%; most preferably 20%.

[0050] In some preferred embodiments, in step 4), the fermentation conditions are as follows: temperature 20 - 35°C, pH 3 - 7, and time not less than 30 days; more preferably, the fermentation conditions are: temperature 24 - 26°C, pH = 4 - 6, and time 30 - 40 days; most preferably, the fermentation conditions are: temperature 25°C, pH = 6, and time 30 days.

[0051] In some preferred embodiments, in step 4), before the Monascus is inoculated into the solid fermentation substrate, it undergoes slant culture and liquid culture in sequence.

[0052] In some more preferred embodiments, the slant culture includes: transferring the refrigerated Monascus to a slant medium and culturing at 25 - 35°C for 5 - 10 days; then transferring it to another slant medium and culturing at 25 - 35°C for 5 - 10 days, and adding sterile water to control the spore amount at 5×10 4 ~2×10 5 cells / mL.

[0053] In some more preferred embodiments, the liquid culture includes: inoculating the bacterial liquid obtained from slant culture into a seed liquid medium at an inoculation amount of 15 - 25%, and culturing at 100 - 300 rpm and 25 - 35°C for 2 - 4 days to obtain a seed liquid. Further, the seed liquid medium includes: 3 - 7 wt% glucose, 0.5 - 2 wt% peptone, 0.5 - 2 wt% yeast powder, 0.1 - 1 wt% KH2PO4, 0.1 - 1 wt% MgSO4, and 0.5 - 2 wt% rice flour.

[0054] In some preferred embodiments, in step 4), the fermentation product is subjected to drying treatment.

[0055] In some preferred embodiments, in the bergamot Monascus fermentation composition, the content of Monacolin K is ≥8 mg / g, the total flavonoid content is ≥11 mg / g, and the polysaccharide content is ≥28 mg / g.

[0056] Specific examples and comparative examples Example 1: Screening of Monascus strains Using different Monascus strains (GM011 provided by Hemudu Monascus Research Institute of Zhejiang University of Technology, GM01 provided by Hangzhou Shangyi Bencao Traditional Chinese Medicine Co., Ltd., GM02 provided by Hemudu Monascus Research Institute of Zhejiang University of Technology) to ferment and produce effective components such as polysaccharides, flavonoids, and Monacolin K, and optimizing the strains. The results are shown in the following table: Strain Monacolin K content (mg / g) Polysaccharide content (mg / g) Total flavonoid content (mg / g) GM011 8.11 31.65 11.59 GM01 6.53 32.37 12.65 GM02 5.38 34.12 11.67 As can be seen from the results in the above table, during the fermentation of the three high-yield Monacolin K strains, the content of Monacolin K in GM011 is the highest, the content of total flavonoids changes little, while the content of polysaccharides decreases as the content of Monacolin K increases. This may be because the strains with high Monacolin K content have a higher product conversion rate and consume sugar more thoroughly. Considering comprehensively, GM011 strain is preferably selected.

[0057] Example 2: Comparison of solid-state co-fermentation of bergamot and indica rice and fermentation on pure indica rice The bergamot and indica rice were mixed and fermented at a mass ratio of 1:3, and the fermentation on pure indica rice with GM011 was compared for the content of fermentation products. The results are shown in the following table: As can be seen from the results in the above table, the content of Monacolin K produced by the fermentation of pure indica rice is slightly higher, but at the same time, the content of polysaccharides and total flavonoids decreases more significantly. This may be related to the fact that the nutritional components of bergamot are fully utilized by Monascus.

[0058] Example 3: Comparison of the raw material ratio of bergamot and indica rice Monascus GM011 was cultured using different ratios of bergamot and indica rice, and the growth of Monascus and the formation of products were observed. The results are shown in the following table: As can be seen from the results in the above table, when the ratio of bergamot to indica rice is relatively high (1:1), it will lead to restricted growth of Monascus. After slow growth, the water produced by growth will decrease, causing the medium to dry out, resulting in insufficient water in the later stage and the growth of Monascus stopping. When the ratio of bergamot to indica rice is reduced to less than 1:2, the inhibitory effect on the growth of Monascus is not obvious, the growth of Monascus proceeds normally, the medium will not dry out, and the growth will not stop. Therefore, after the normal growth of Monascus, the content of Monacolin K increases rapidly. When the ratio continues to decrease to less than 1:3, the growth rate slows down significantly, and at the same time, the content of total flavonoids decreases significantly. Since the growth will stop when the ratio of bergamot to indica rice is relatively high, Monascus produces less polysaccharides, resulting in a relatively low polysaccharide content. Therefore, the optimal ratio is 1:3.

[0059] Example 4: Influence of different bergamot pretreatment methods on the fermentation of Monascus (1) The raw materials of fresh bergamot before and after distillation to extract essential oil were compared for the Monascus fermentation test, and the growth of Monascus GM011 and the formation of products were compared. The results are shown in the following table: It can be seen from the data comparison in the above table that: due to the relatively high content of active essential oil components in fresh bergamot without treatment, the growth of Monascus purpureus was inhibited at the beginning. After 30 days of the same fermentation, the content of Monacolin K obtained was significantly lower, and the polysaccharide content was relatively higher than that of the untreated one. This may be because the natural polysaccharide components in bergamot are relatively well preserved. The total flavonoid content is relatively low after rectification, which may be related to the decomposition of flavonoids caused by rectification under high-temperature conditions.

[0060] (2) Compare the effects of drying bergamot at 40°C, 45°C, 50°C, 55°C, and 60°C on the growth and product formation of Monascus purpureus GM011. The results are shown in the following table: It can be seen from the data comparison in the above table that different drying temperatures have little effect on the production of Monacolin K and polysaccharide content by Monascus purpureus, but have a relatively large effect on the total flavonoid content. When the drying temperature is below 50°C, the flavonoid content is not affected much. When the drying temperature is above 50°C, the flavonoid content will decrease significantly. This may be due to a small amount of damage to the flavonoids in bergamot due to high temperature at the beginning. Therefore, the drying temperature below 50°C is more appropriate.

[0061] (3) The effects of four drying methods of bergamot, namely drying at 50°C, natural drying, shade drying, and microwave drying, on the growth and product formation of Monascus purpureus GM011 are shown in the following table: It can be seen from the data comparison in the above table that the four drying methods of drying at 50°C, natural drying, shade drying, and microwave drying have little effect on the growth of Monascus purpureus, and there is basically no significant difference. The growth of the shade drying method is slightly slower. In terms of products, the shade drying method has a higher flavonoid content and a relatively lower Monacolin K content. This may be because after the growth of Monascus purpureus slows down, the product formation is also relatively slower.

[0062] Example 5: Effects of solid-state fermentation media with different moisture contents on the growth and product formation of Monascus purpureus Solid-state fermentation was carried out using solid-state fermentation media with moisture contents of 15%, 20%, 25%, 30%, 35%, 40%, 45%, and 50% respectively. The results are shown in the following table: According to the data in the above table, the growth of Monascus in media with different moisture contents varies greatly. When the moisture content is low, the growth of Monascus is slow or even stops. When the moisture content is above 30%, the growth of Monascus is better. When the moisture content exceeds 40%, since the solid is in a paste state, it is not conducive to the transfer of oxygen, mass transfer is difficult, and it is not conducive to the formation of secondary metabolites, so the content of Monacolin K decreases. Therefore, the optimal moisture content is 35%.

[0063] Example 6: Optimization of the Solid Fermentation Process Parameters of Bergamot Monascus The factors affecting the solid fermentation conditions of bergamot Monascus are: the inoculation amount of the strain, the pH of fermentation, the temperature of fermentation, the time of fermentation, etc. First, single-factor experiments are carried out to obtain the more suitable fermentation conditions for bergamot Monascus fermentation. Then, orthogonal experiments are carried out for analysis.

[0064] (1) Experiment on the effect of different inoculation amounts on the fermentation of Monascus. Cultivation of Monascus: Transfer the refrigerated Monascus GM011 to a slant medium and culture it at 30°C for 7 days; then transfer it to another slant medium and culture it at 30°C for 10 days, and add sterile water to control the spore amount at 5×10 4 ~2×10 5 cells / mL. Inoculate the bacterial liquid obtained from slant culture into the seed liquid medium (5% glucose, 1% peptone, 1% yeast powder, 0.5% KH2PO4, 0.2% MgSO4, 1% rice flour) at an inoculation amount of 20%, and culture it at 200 rpm and 30°C for 3 d to obtain the seed liquid.

[0065] Inoculation and fermentation of the solid medium: When the solid medium cools to room temperature, inoculate different amounts of seed liquid.

[0066] Investigate the effects of inoculation amounts of 5%, 10%, 15%, 20%, 25%, and 30% on the fermentation of bergamot Monascus. The results are shown in the following table and Figure 1 as follows:[[]]END]] From the above table and Figure 1It can be seen that when the inoculation amount is low, the growth state of Monascus is poor, the content of Monacolin K produced is low, and the flavonoid content is relatively high. As the inoculation amount increases, the content of Monacolin K increases rapidly. When the inoculation amount reaches 20%, the content of Monacolin K decreases instead. This is because when the inoculation amount is large, the corresponding increase in water content makes the whole material more viscous, affecting the oxygen absorption, nutrient transfer and product formation of the material. Since the natural flavonoids in the bergamot are not affected by the growth of Monascus when the inoculation amount is low, the flavonoid content is relatively high. When the inoculation amount increases, the content decreases. After the inoculation amount reaches 15%, the content no longer decreases, probably because the natural flavonoids are no longer affected and flavonoids are formed during the growth of Monascus. The polysaccharide content is also low when the inoculation amount is low, indicating that Monascus does not grow to produce Monascus polysaccharide. After the inoculation amount reaches 20% with the growth, the polysaccharide content no longer increases but decreases instead. This may be due to more decomposition of the polysaccharide in the bergamot and less production of Monascus polysaccharide. Based on the above phenomena, an inoculation amount of 20% is more appropriate.

[0067] (2) Influence of fermentation temperature Investigate the influence of different temperatures (20°C, 25°C, 30°C, 35°C) of Monascus strains on fermentation. The normal growth temperature of Monascus is between 20 and 35°C. When the temperature is too low, the growth rate is too slow, resulting in an extended fermentation time and increased difficulty in fermentation control. When the temperature is too high, it will lead to enzyme inactivation, damage to the cell membrane structure, metabolic disorders, etc., growth inhibition, reduction of metabolites, and a decrease in product yield. Therefore, choosing an appropriate fermentation temperature is crucial for the formation of bergamot Monascus products. Therefore, we investigated the temperatures: 20°C, 25°C, 30°C, 35°C, and other fermentation conditions: pH 6, inoculation amount 20%, fermentation for 30 days, and measured the content of Monacolin K and total flavonoids after the fermentation ended.

[0068] It can be seen from Figure 2 that the content of Monacolin K reaches the peak at 25°C, and the total flavonoid content decreases slightly with the increase of the culture temperature, and the decrease amplitude is not large. Therefore, the optimal fermentation temperature is about 25°C.

[0069] (3) Influence of fermentation pH Under a suitable slightly acidic environment, the growth, reproduction and fermentation of Monascus are all very rapid. An appropriate pH value can ensure the rapid growth of Monascus and can better play the role of inhibiting harmful microorganisms. Since Monascus is suitable for growing under slightly acidic conditions, we adjusted the pH of the material to 3, 4, 5, 6, 7 with hydrochloric acid respectively, fermented at 25°C for 30 days, and measured the content of Monacolin K and total flavonoids in the solid-state fermentation products. The results are shown in Figure 3 .

[0070] It can be seen fromFigure 3 It can be seen that the content of Monacolin K reaches its peak at a pH value of 6. The total flavonoid content remains basically unchanged when the pH value is below 6, and decreases significantly when it exceeds 6. Therefore, we carried out fermentation culture at a pH value of around 6.

[0071] (4) Influence of fermentation time The influence of fermentation time on product accumulation is one of the key factors in the fermentation process, and is closely related to the microbial growth stage, metabolic characteristics, and product synthesis pathway. If the fermentation time is too short: the product has not reached the maximum accumulation, the yield is low, and the body's metabolic potential has not been fully released (especially for secondary metabolites). If the time is too long, it increases the risk of bacterial contamination, product degradation, energy waste, and by-product accumulation. According to the characteristics of secondary metabolite production by Monascus, we determined the culture time to be 15d, 20d, 25d, 30d, 35d, and 40d for cultivation, and observed the changes in the content of Monacolin K and total flavonoids in the solid-state fermentation products. The results are shown in Figure 4 .

[0072] From Figure 4 it can be seen that after the fermentation time exceeds 15d, the influence on the total flavonoid content is not obvious. The content of Monacolin K increases significantly with the extension of the fermentation time. When it exceeds 30d, the growth is slow and not obvious. Therefore, it is more appropriate for us to adopt a fermentation time of 30d.

[0073] (5) Orthogonal test for optimizing fermentation conditions Based on the above test results and considering the interaction effects among the factors of inoculum size, pH, temperature, and culture time, an L9(3 4 ) orthogonal array was used for the test to investigate the effects of various influencing factors on Monacolin K and total flavonoids. Finally, the optimal conditions for optimizing the fermentation conditions were determined, and the arrangement of factors and levels is shown in the following table.

[0074] The range analysis of the Monacolin K results shows that the influence of each factor index in the test is: D > A > C > B. According to the magnitude of its K max value, the optimal fermentation process conditions are A3B2C2D3. We observed that the differences between A2 and A3, and D2 and D3 are very small. Since a large inoculum size will increase the pressure on the preparation of the seed medium in the early stage, and a long culture time will increase the risk of bacterial contamination, and at the same time, all production costs will increase. Therefore, when the differences are not significant, we adopted the combination of A2B2C2D2, that is, the inoculum size is 20%, the temperature is 25°C, the pH value is 6, and the culture time is 30d. The range analysis of the total flavonoid results shows that the influence of each factor index in the test is: C > A > B > D. According to its K maxFrom the magnitude of the values, the optimal fermentation process conditions are A1B1C1D2. We observed that the differences between A1 and A2, B1 and B3, C1 and C2, D1 and D2 are very small, indicating that the effects of various factors on the total flavonoid content are not significantly different. Only when the pH value exceeds 6, the total flavonoid content decreases significantly. Based on the above results, we used the combination of A2B2C2D2, that is, 20% inoculum amount, 25 °C, pH = 6, and a culture time of 30 days for solid fermentation culture.

[0075] Example 7: Preparation of the fermented composition product of bergamot and Monascus (1) Pretreatment of bergamot and indica rice: The fresh bergamot is dried at 50 °C to remove essential oil components; the bergamot and indica rice are ground into powder and screened through a 0.6 mm sieve.

[0076] (2) The mass ratio of bergamot powder to indica rice powder is 1:3, water is added, and they are mixed evenly to obtain a solid fermentation substrate with a moisture content of 35%, which is filled into edible mushroom cultivation bags.

[0077] (3) Select the Monascus strain GM011. The refrigerated strain is transferred to a slant medium and cultured at 30 °C for 7 days, then transferred to another slant medium and cultured at 30 °C for 10 days. Sterile water is added to control the spore amount at 5×10 4 ~2×10 5 cells / mL. The bacterial liquid obtained from the slant culture is inoculated into the seed liquid medium (5% glucose, 1% peptone, 1% yeast powder, 0.5% KH2PO4, 0.2% MgSO4, 1% rice flour, and the rest is water) at an inoculum amount of 20%, and cultured at 200 rpm and 30 °C for 3 days to obtain the seed liquid.

[0078] (4) Inoculation and fermentation of the solid medium: When the solid fermentation substrate cools to room temperature, the seed liquid is inoculated at an inoculum amount of 20%. The fermentation conditions are: temperature 25 °C, pH = 6, shake once every 2 - 3 days, and discharge the material after 30 days of fermentation. After drying at 50 °C, the fermented composition product of bergamot and Monascus is obtained, with a Monacolin K content of 8.23 mg / g, a total flavonoid content of 11.51 mg / g, and a polysaccharide content of 28.11 mg / g.

[0079] In the present invention, the raw materials and equipment used, unless otherwise specified, are common raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are conventional methods in the art.

[0080] The above are only the preferred embodiments of the present invention, and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent transformations made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A preparation method of a bergamot red yeast rice fermentation composition, characterized in that Comprising: 1) Removing the essential oil components from the fingered citron; 2) Making the fingered citron obtained in 1) and rice into powder; 3) Mixing the fingered citron powder, rice powder and water to obtain a solid-state fermentation substrate; 4) Inoculating Monascus spp. into the solid-state fermentation substrate for fermentation, and the fermentation product is the fingered citron Monascus fermentation composition.

2. The preparation method according to claim 1, wherein: In step 1), The essential oil components are removed by a drying method, and the drying method is one or a combination of more of drying in an oven, natural sun drying, drying in the shade and microwave drying; The temperature of the drying in the oven is 40 - 50 °C.

3. The preparation method according to claim 1, characterized in that: In step 2), the rice is indica rice.

4. The preparation method according to claim 1, wherein: In step 3), The mass ratio of the fingered citron powder to the rice powder is 1:3 - 1:2; The moisture content of the solid-state fermentation substrate is 30 - 40 wt%.

5. The preparation method according to claim 1, wherein: In step 4), The Monascus spp. includes one or more of Monascus purpureus, Monascus anka, Monascus pilosus, Monascus ruber; The inoculation amount of the Monascus spp. is 15 - 30%; The fermentation conditions are: temperature 20 - 35 °C, pH 3 - 7, and time not less than 30 days.

6. The preparation method according to claim 5, characterized in that: In step 4), The Monascus spp. includes one or more of Monascus GM011, Monascus GM01 and Monascus GM02; The inoculation amount of the Monascus spp. is 20 - 25%; The fermentation conditions are: temperature 24 - 26 °C, pH = 4 - 6, and time 30 - 40 days.

7. The preparation method according to claim 6, characterized in that: In step 4), The Monascus spp. includes Monascus GM011; The inoculation amount of the Monascus spp. is 20%; The fermentation conditions are: temperature 25 °C, pH = 6, and time 30 days.

8. The preparation method according to claim 1 or 5 or 6 or 7, characterized in that: In step 4), before the Monascus spp. is inoculated into the solid-state fermentation substrate, it is successively subjected to slant culture and liquid culture.

9. The preparation method according to claim 8, wherein: The slant culture includes: transferring refrigerated Monascus to a slant medium and culturing at 25 - 35°C for 5 - 10 days; then transferring it to another slant medium and culturing at 25 - 35°C for 5 - 10 days, and adding sterile water to control the spore amount at 5×10 4~ 2×10 5 cells / mL; The liquid culture includes: transferring the bacterial liquid obtained from the slant culture to the seed liquid medium at an inoculation amount of 15 - 25%, and culturing for 2 - 4 d at 100 - 300 rpm and 25 - 35 °C to obtain the seed liquid.

10. The preparation method according to claim 1, characterized in that: In the fingered citron Monascus fermentation composition, the content of Monacolin K is ≥ 8 mg / g, the total flavonoid content is ≥ 11 mg / g, and the polysaccharide content is ≥ 28 mg / g.

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