Monascus cheese and preparation method thereof

Abstract

The invention relates to a maturing process of cheese, in particular to monascus cheese and a preparation method thereof. The invention provides a maturing method of monascus cheese with high biological activity, which comprises the following steps: maturing molded cheese under the following conditions: maturing the molded cheese for 8-10 days under the conditions that the temperature is 28-32 DEG C and the humidity is 50-60%, and then maturing for 23-27 days under the conditions that the temperature is 12-15 DEG C and the humidity is 80-90%. The invention also provides a preparation method of the monascus cheese with high biological activity. Comprising the following steps: obtaining molded cheese, and maturing the molded cheese by adopting the maturing method to obtain the monascus cheese with high biological activity. According to the method, the maturation period and the preparation period of the monascus cheese can be shortened, and the prepared monascus cheese has good flavor, taste and maturity and has high biological activity.

Description

Technical Field

[0001] The present application relates to a cheese ripening process, and in particular, to a Monascus cheese and a preparation method thereof. Background Art

[0002] Monascus cheese is a new type of mold cheese product that has emerged in recent years. The Monascus introduced in its production process is one of my country's important medicinal and edible microbial resources with a long history of application. Monascus fermented foods, such as Monascus fermented bean curd and Monascus soy sauce, are widely accepted for their unique flavor, and a variety of beneficial active substances can be produced during the fermentation process, such as Monascus pigment, lovastatin, and γ-aminobutyric acid. Compared with other types of mold cheese (such as blue cheese), Monascus cheese is more suitable for the taste preferences of Chinese consumers in terms of taste and odor intensity, showing huge market development potential.

[0003] However, the Monascus cheese prepared according to the prior art usually requires a maturation cycle of at least one month. The maturation method mainly adopts variable temperature maturation, that is, it is first matured at 25-30°C for 3-5 days. After the Monascus covers the surface, it is transferred to an environment of 12-15°C or 4°C to continue the remaining maturation process until the end. A short maturation period will lead to insufficient taste and flavor, and poor texture. High maturation temperature and too fast maturation may cause excessive mold growth, unbalanced flavor, soft texture, and even food safety risks. Cheese is rich in protein and is an important natural source of bioactive peptides. A low degree of protein hydrolysis will lead to insufficient production of functional active peptides, and a high degree of protein hydrolysis may cause excessive hydrolysis of active peptides to reduce or lose their activity, accompanied by the formation of unpleasant flavors, thereby affecting the overall quality attributes of Monascus cheese.

[0004] The Chinese patent application (202211704622.3) discloses a method for preparing Monascus cheese and develops a small-jar independent maturation process. However, the cheese needs to be cut into 5 equal portions and packaged for maturation, and a 14-day high-temperature short-term maturation process is adopted. Although it effectively avoids problems such as contamination and long production cycle, it causes the musty smell brought by Monascus to be relatively heavy at the end of cheese maturation. Cutting it into five equal portions also reduces production efficiency, which is not conducive to future industrial production.

[0005] Therefore, in the prior art, it is difficult to simultaneously shorten the ripening time, control the appropriate maturity of the cheese product, and improve the biological activity of the cheese product. Summary of the invention

[0006] The present application develops a suitable Monascus cheese ripening process and preparation method. By combining the growth characteristics of Monascus, the ripening time originally at a higher temperature is extended, so that it can grow fully on the cheese, and then transferred to 15°C for further ripening. The ripening process uses a constant temperature and humidity ripening box to achieve precise control of the ripening temperature, ripening time and humidity, ensuring that the final product shortens the overall ripening time while ensuring quality and improving its biological activity. Compared with traditional existing technologies, the present application not only improves production efficiency and improves product quality by optimizing temperature and time control strategies, but also better retains the unique aroma and taste of Monascus, avoids problems such as softening of texture caused by rapid ripening, and enhances the biological activity of the product. The cheese is rich in antioxidant, ACE inhibitory peptides, hypoglycemic, antibacterial and other functional active peptides, which help to enhance product value and meet the diverse needs of consumers.

[0007] The first aspect of the present application provides a method for ripening Monascus cheese with high biological activity, comprising ripening the shaped cheese under the following conditions: the shaped cheese is first ripened at 28-32°C and 50-60% humidity for 8-10 days, and then transferred to 12-15°C and 80-90% humidity for 23-27 days.

[0008] The second aspect of the present application provides a method for preparing Monascus cheese with high biological activity, comprising obtaining shaped cheese, and then ripening the shaped cheese using the Monascus cheese ripening method of the first aspect to obtain the Monascus cheese with high biological activity.

[0009] Preferably, the method of obtaining shaped cheese comprises the following steps: raw material pretreatment, fermentation, curdling, and shaping.

[0010] Preferably, the step of obtaining the shaped cheese comprises the following steps:

[0011] 1) Raw material pretreatment: standardize the raw milk and cream, perform the first stirring, sterilize and cool to obtain the pretreated product;

[0012] 2) fermentation: inoculating the pretreated product with a lactic acid bacteria starter and a Monascus filtered bacterial liquid, stirring for a second time, and fermenting to obtain a fermented product;

[0013] 3) Curdling: the fermented product is mixed with rennet, and the milk is curdled to obtain curd;

[0014] 4) Molding process: molding the curd block to obtain molded cheese.

[0015] The third aspect of the present application provides use of the ripening method of the first aspect or the preparation method of the second aspect in improving the biological activity of Monascus cheese.

[0016] Preferably, the biological activity includes antioxidant activity, and / or ACE inhibitory activity.

[0017] A fourth aspect of the present application provides a Monascus cheese, which is obtained by ripening shaped cheese by the ripening method of the first aspect, or prepared by the preparation method of the second aspect.

[0018] The beneficial effects of this application are:

[0019] The present application optimizes the ripening conditions according to the growth characteristics of Monascus, and the provided ripening process and preparation method can shorten the ripening time under the premise of ensuring the quality of Monascus cheese, and also avoid the problems of softening texture caused by rapid ripening, and make the prepared product have good tissue state, fine texture, attractive color, good flavor and taste, high maturity, good biological activity, rich in antioxidant, ACE inhibitory peptides, hypoglycemic, antibacterial and other functional active peptides, and its DPPH free radical scavenging rate can reach 55.65% to 60.12%, and its ACE inhibitory activity can reach 75.34% to 79.25%, with high biological activity, including 19 ACE inhibitory peptides, 20 antioxidant peptides, 11 DPP-IV inhibitory peptides and 9 antibacterial peptides, etc., rich in variety and content, and better sensory organs and flavor. In addition, the preparation process largely avoids contamination by other bacteria during the ripening period, shortens the ripening period, and improves production efficiency. In addition, because the ripening conditions are optimized according to the growth characteristics of Monascus, its characteristic flavor is more obvious and the degree of protein hydrolysis is higher. It also provides a reference for the optimization of ripening conditions for the production of other Monascus cheeses, further reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The Monascus cheese prepared in Example 1 of the present application is more mature and has better color, flavor and texture.

[0021] Figure 2 This is the Monascus cheese prepared in Comparative Example 1. DETAILED DESCRIPTION

[0022] The following describes the implementation of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. The present application can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application.

[0023] Before further describing the specific implementation methods of the present application, it should be understood that the scope of protection of the present application is not limited to the specific specific implementation methods described below; it should also be understood that the terms used in the examples of the present application are for describing specific specific implementation methods rather than for limiting the scope of protection of the present application; in the specification and claims of the present application, unless otherwise expressly stated herein, the singular forms "a", "an" and "the" include plural forms.

[0024] When the embodiments give numerical ranges, it should be understood that, unless otherwise specified in the present application, the two endpoints of each numerical range and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those generally understood by those skilled in the art. In addition to the specific methods, equipment, and materials used in the embodiments, according to the grasp of the prior art by those skilled in the art and the record of the present application, any method, equipment, and material of the prior art similar or equivalent to the methods, equipment, and materials described in the embodiments of the present application can also be used to realize the present application.

[0025] The present application optimizes the maturation conditions according to the growth characteristics of Monascus, and the provided maturation process and preparation method can shorten the maturation time while ensuring the quality of Monascus cheese, and make the prepared product have good tissue state, fine texture, attractive color, good flavor and taste, high maturity, good biological activity, rich in antioxidant, ACE inhibitory peptides, hypoglycemic, antibacterial and other functional active peptides, its DPPH free radical scavenging rate can reach 55.65% to 60.12%, and its ACE inhibitory activity can reach 75.34% to 79.25%, with high biological activity, and at the same time, better sensory organs and flavor.

[0026] In this application, the biological activity refers to the specific physiological effects or pharmacological actions of certain substances (usually naturally occurring compounds or synthetic molecules) in vivo or in a simulated in vivo environment. These substances can interact with molecules in the body (such as proteins, enzymes, receptors, etc.), thereby affecting the normal physiological function or pathological state of the organism, such as antioxidant, anti-inflammatory, ACE inhibitory activity, antibacterial activity, and anticancer activity.

[0027] In the present application, the biological activity refers to antioxidant activity and ACE inhibitory activity. Specifically, the high biological activity refers to high antioxidant activity and high ACE inhibitory activity.

[0028] The antioxidant property includes DPPH free radical scavenging rate. In the present application, the high antioxidant property may refer to a DPPH free radical scavenging rate that can reach 55.65% to 60.12%.

[0029] The ACE inhibitory activity includes the ACE inhibition rate. In the present application, the high ACE inhibition activity may refer to an ACE inhibition rate of 75.34% to 79.25%. The ACE inhibition rate refers to the degree of inhibition of ACE activity by angiotensin-converting enzyme (ACE) inhibitory peptides, usually expressed as a percentage. ACE is an enzyme that can convert angiotensin I into angiotensin II, which is a strong vasoconstrictor that can increase blood pressure. Therefore, the ACE inhibition rate reflects the ability of a substance or peptide to inhibit ACE activity, thereby lowering blood pressure.

[0030] The present application first provides a method for ripening Monascus cheese with high biological activity, comprising ripening the shaped cheese under the following conditions: the shaped cheese is first ripened at 28-32°C and 50-60% humidity for 8-10 days, and then transferred to 12-15°C and 80-90% humidity for 23-27 days.

[0031] In the present application, the molded cheese refers to the cheese obtained in the previous step of the ripening process during the cheese preparation process, such as the cheese obtained through raw material pretreatment, fermentation, coagulation, cutting, whey drainage, mold molding, salt soaking, and drying.

[0032] In a specific embodiment of the present application, the ripening method is divided into two stages, namely, the first stage ripening and the second stage ripening. In the first stage ripening, the ripening temperature is 28-32°C, for example, 28-29°C, 29-30°C, 30-31°C, 31-32°C, the ripening humidity is 50-60%, for example, 50-51%, 51-52%, 52-53%, 53-54%, 54-55%, 55-56%, 56-57%, 57-58%, 58-59%, 59-60%, and the ripening time is 8-10d, for example, 8-8.5d, 8.5-9d, 9-9.5d, 9.5-10d; in the first stage ripening, the ripening time at a higher temperature is extended to allow Monascus to grow fully on the cheese; in the second stage ripening, the ripening temperature is 40°C, 80°C, 80°C, 80°C, 80°C, 80°C, 80°C, 80°C, 80°C, 80°C, 80°C, 80°C, 80°C, 80°C, 80°C The ripening temperature is 12-15°C, for example, 12-13°C, 13-14°C, 14-15°C, the ripening humidity is 80-90%, for example, 80-81%, 81-82%, 82-83%, 83-84%, 84-85%, 85-86%, 86-87%, 87-88%, 88-89%, 89-90%, and the ripening time is 23-27d, for example, 23-24d, 24-25d, 25-26d, 26-27d. The second stage of ripening is shortened in the present application, that is, the ripening period is shortened. The ripening method of the present application matches the growth characteristics of Monascus, which not only shortens the overall ripening time, but also is conducive to the growth of Monascus, thereby being beneficial to the flavor, texture, and biological activity of Monascus cheese, including antioxidant activity and ACE inhibitory activity.

[0033] In a specific embodiment of the present application, the ripening method further includes placing the formed cheese in a ripening apparatus and then placing it in a constant temperature and humidity ripening box for ripening under the above conditions. The ripening apparatus refers to a container that can perform sterile gas exchange and needs to be replaced from time to time during the ripening period.

[0034] In a specific embodiment of the present application, the method for preparing the molded Monascus includes: using Monascus to filter bacterial liquid for fermentation.

[0035] In a specific embodiment of the present application, the preparation method of the Monascus filtered bacterial liquid is to take a small amount of Monascus hyphae and inoculate it into PDB medium, culture it at 170r / min and 32°C for 7 days, filter it with sterile absorbent cotton, and the live bacteria content of the filtrate is about 10 6 CFU / L. The filtrate was stored at room temperature and prepared immediately before use.

[0036] In a specific embodiment of the present application, the monascus is a conventional strain in the art, preferably selected from any one or more of red monascus BC20, red monascus ZX99, and purple monascus strain M.CJ233. Further, red monascus BC20, red monascus ZX99, and purple monascus strain M.CJ233 are all from the strain library of Guangming Dairy Research Institute, wherein the preservation number of purple monascus strain M.CJ233 is CGMCC No.18563, and the classification name is Monascus sp.. The strain was deposited in the General Microbiological Center (CGMCC) of the China Microbiological Culture Collection Administration on September 2, 2019, and the preservation address is No. 3, No. 1, Beichen West Road, Chaoyang District, Beijing. In this application, monascus is matched with the maturation method, so as to shorten the maturation time and improve the flavor, taste and biological activity of monascus cheese to the greatest extent, thereby shortening the preparation time of monascus cheese, improving product quality, and improving the biological activity of monascus cheese.

[0037] The present application also provides a method for preparing Monascus cheese with high biological activity, comprising obtaining molded Monascus cheese, and then maturing the molded cheese using the above-mentioned Monascus cheese maturation method to obtain the Monascus cheese with high biological activity.

[0038] In a specific embodiment of the present application, the method of obtaining the shaped cheese includes the following steps: raw material pretreatment, fermentation, coagulation, and shaping.

[0039] In a specific embodiment of the present application, the step of obtaining the formed cheese comprises the following steps:

[0040] 1) Raw material pretreatment: standardize the raw milk and cream, perform the first stirring, sterilize and cool to obtain the pretreated product;

[0041] 2) fermentation: inoculating the pretreated product with a lactic acid bacteria starter and a Monascus filtered bacterial liquid, stirring for a second time, and fermenting to obtain a fermented product;

[0042] 3) Curdling: the fermented product is mixed with rennet, and the milk is curdled to obtain curd;

[0043] 4) Molding process: molding the curd block to obtain molded cheese.

[0044] In a specific embodiment of the present application, in step 1), the standardization is to mix raw milk and cream to obtain a mixture, and the mass ratio of fat to protein in the mixture is 1.5 to 1.7:1; for example, it can be 1.5:1, 1.6:1, or 1.7:1.

[0045] In a specific embodiment of the present application, in step 1), the rotation speed of the first stirring is 400-600rpm, for example, it can be 400-420rpm, 420-440rpm, 440-460rpm, 460-480rpm, 480-500rpm, 500-520rpm, 520-540rpm, 540-560rpm, 560-580rpm, 580-600rpm, and the time of the first stirring is 30-50min, for example, it can be 30-32min, 32-34min, 34-36min, 36-38min, 38-40min, 40-42min, 42-44min, 44-46min, 46-48min, 48-50min.

[0046] In a specific embodiment of the present application, in step 1), the sterilization is performed by pasteurization.

[0047] In certain embodiments of the present application, in step 1), the sterilization temperature is 68-72°C, for example, 68-69°C, 69-70°C, 70-71°C, 71-72°C, and the sterilization time is 15-25s, for example, 15-16s, 16-17s, 17-18s, 18-19s, 19-20s, 20-21s, 21-22s, 22-23s, 23-24s, 24-25s.

[0048] In a specific embodiment of the present application, in step 1), the cooling is cooling to 32-35°C, for example, 32-33°C, 33-34°C, 34-35°C.

[0049] In a specific embodiment of the present application, in step 2), the lactic acid bacteria starter includes Flora Danica starter and STI-13 starter, for example, a product of Chr. Hansen.

[0050] In a specific embodiment of the present application, in step 2), the addition amount of the lactic acid bacteria fermentation agent is 10-12U / 100L pretreated material, which means that 10-12U of lactic acid bacteria fermentation agent is added to every 100L of pretreated material obtained in step 1), for example, it can be 10-10.5U / 100L, 10.5-11U / 100L, 11-11.5U / 100L, 11.5-12U / 100L.

[0051] In a specific embodiment of the present application, the preparation method of the Monascus filtrate is to take a small amount of Monascus hyphae and inoculate it into PDB culture medium, culture it at 170r / min and 32°C for 7 days, filter it with sterile absorbent cotton, and the live bacteria content of the filtrate is about 106CFU / L. The filtrate is stored at room temperature and prepared on the spot.

[0052] In a specific embodiment of the present application, the Monascus is a conventional strain in the art, and can be any one or more of red Monascus BC20, red Monascus ZX99, and purple Monascus strain M.CJ233. Further, red Monascus BC20, red Monascus ZX99, and purple Monascus strain M.CJ233 are all from the strain library of Bright Dairy Research Institute.

[0053] In one embodiment of the present application, the Monascus is a purple Monascus strain M.CJ233, whose deposit number is CGMCC No. 18563 and whose classification name is Monascus sp. The strain was deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration (CGMCC) on September 2, 2019, and the deposit address is No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing.

[0054] In a specific embodiment of the present application, the addition amount of the Monascus filtered bacterial liquid is 10-12 mL / 10 kg of pretreated material, which means that 10-12 mL of Monascus filtered bacterial liquid is added to every 10 kg of pretreated material obtained in step 1), for example, it can be 10-10.5 mL / 10kg, 10.5-11 mL / 10kg, 11-11.5 mL / 10kg, 11.5-12 mL / 10kg. At this addition amount, it is beneficial to the fermentation of Monascus, as well as the matching and combination with the maturation method, thereby improving the flavor, quality and biological activity (antioxidant and ACE inhibitory activity) of Monascus cheese.

[0055] In a specific embodiment of the present application, in step 2), the rotation speed of the second stirring is 100-300 rpm, for example, it can be 100-120 rpm, 120-140 rpm, 140-160 rpm, 160-180 rpm, 180-200 rpm, 200-220 rpm, 220-240 rpm, 240-260 rpm, 260-280 rpm, 280-300 rpm; the time of the second stirring is 3-5 min, for example, it can be 3-3.5 min, 3.5-4 min, 4-4.5 min, 4.5-5 min.

[0056] In a specific embodiment of the present application, in step 2), the fermentation may be static fermentation.

[0057] In a specific embodiment of the present application, in step 2), the fermentation temperature is 35-39°C, for example, 35-36°C, 36-37°C, 37-38°C, 38-39°C, and the fermentation time is 1.5-2h, for example, 1.5-1.6h, 1.6-1.7h, 1.7-1.8h, 1.8-1.9h, 1.9-2h. Under these conditions, it is conducive to the growth of lactic acid bacteria and Monascus.

[0058] In a specific embodiment of the present application, in step 3), the pH of the fermented product when mixed with rennet is 6.3-6.4, which means that when the pH of the fermented product obtained by fermentation in step 2) is 6.3-6.4, the fermented product is mixed with rennet.

[0059] In a specific embodiment of the present application, in step 3), the amount of rennet added is 0.05-0.08 g / 10 kg of fermentation product, which means that 0.05-0.08 g of rennet is added to every 10 kg of fermentation product obtained in step 2), for example, it can be 0.05-0.06 g / 10 kg, 0.06-0.07 g / 10 kg, or 0.07-0.08 g / 10 kg.

[0060] In a specific embodiment of the present application, in step 3), the fermented product and rennet may be mixed by stirring so that the fermented product and rennet are evenly mixed, and there is no limitation on the stirring conditions, and the fermented product and rennet only need to be mixed evenly.

[0061] In a specific embodiment of the present application, in step 3), the curd may be static curd.

[0062] In a specific embodiment of the present application, in step 3), the coagulation time is 45 to 60 min, for example, it can be 45 to 46 min, 46 to 47 min, 47 to 48 min, 48 to 49 min, 49 to 50 min, 50 to 51 min, 51 to 52 min, 53 to 54 min, 54 to 55 min, 55 to 56 min, 56 to 57 min, 57 to 58 min, 59 to 60 min.

[0063] In a specific embodiment of the present application, in step 4), the molding process includes cutting the curd obtained in step 3), stirring it for the third time, molding it, turning it over, salting it, and drying it, so as to obtain molded cheese, which is used for the subsequent ripening method steps.

[0064] In a specific embodiment of the present application, the cutting refers to cutting the curd into small curd pieces with a volume of 2×2×2 cm using a cutting knife.

[0065] In a specific embodiment of the present application, the third stirring is stirring for 30 to 40 seconds, standing for 1 to 1.5 minutes, and repeated 3 to 4 times, for example, stirring for 30 to 32 seconds, 32 to 34 seconds, 34 to 36 seconds, 36 to 38 seconds, 38 to 40 seconds, standing for 1 to 1.1 minutes, 1.1 to 1.2 minutes, 1.2 to 1.3 minutes, 1.3 to 1.4 minutes, and 1.4 to 1.5 minutes. The stirring can be performed by gently stirring the cut curd with an instrument to separate the curd and whey and discharge part of the whey.

[0066] In a specific embodiment of the present application, the molding refers to adding the curd after the third stirring into the mold and draining the whey to initially shape the cheese.

[0067] In a specific embodiment of the present application, the turning treatment time is 3 to 4 hours, for example, 3 to 3.2 hours, 3.2 to 3.4 hours, 3.4 to 3.6 hours, 3.6 to 3.8 hours, 3.8 to 4 hours, and the turning treatment temperature is 18 to 22°C, for example, 18 to 19°C, 19 to 20°C, 20 to 21°C, 21 to 22°C, and the cheese is turned over every 45 to 50 minutes, for example, every 45 to 46 minutes, 46 to 47 minutes, 47 to 48 minutes, 48 ​​to 49 minutes, 49 to 50 minutes, so that the initially formed cheese can discharge whey and mature more evenly.

[0068] In a specific embodiment of the present application, the whey can be discharged by conventional methods in the art.

[0069] In a specific embodiment of the present application, the salting is to soak the curd after turning over in 16-20wt% sterile saline for 30-60min; for example, it can be 16-17wt%, 17-18wt%, 18-19wt%, 19-20wt% sterile saline, for example, the soaking time can be 30-35min, 35-40min, 40-45min, 45-50min, 50-55min, 55-60min.

[0070] In a specific embodiment of the present application, the drying is to place the salted curd at 14-16°C for 10-14 hours. For example, the placing temperature can be 14-15°C, 15-16°C, and the placing time can be 10-11 hours, 11-12 hours, 12-13 hours, 13-14 hours. More specifically, the salted curd is put back into the mold and placed at 14-16°C for 10-14 hours.

[0071] The present application also provides the use of the above-mentioned ripening method or the above-mentioned preparation method in improving the biological activity of Monascus cheese.

[0072] In certain embodiments of the present application, the biological activity includes antioxidant activity and / or ACE inhibitory activity, that is, the use is to improve the antioxidant activity of Monascus cheese and / or improve the ACE inhibitory activity of Monascus cheese.

[0073] The present application improves the ability of Monascus to hydrolyze protein and the degree of protein hydrolysis in Monascus cheese by matching the growth characteristics and growth curve of Monascus with the maturation process, thereby increasing the content of short peptides and free amino acids in Monascus cheese, increasing the maturity, shortening the time required to reach the desired maturity, and improving the biological activity of Monascus, including antioxidant and ACE inhibitory activity. The DPPH free radical scavenging rate can reach 55.65% to 60.12%, and the ACE inhibitory activity can reach 75.34% to 79.25%. The invention includes 19 ACE inhibitory peptides, 20 antioxidant peptides, 11 DPP-IV inhibitory peptides and 9 antimicrobial peptides, etc., with rich types and contents, and better sensory organs and flavor.

[0074] The present application also provides a Monascus cheese, which is obtained by ripening the shaped cheese by the above-mentioned ripening method, or is prepared by the above-mentioned preparation method.

[0075] The Monascus cheese prepared in the present application has high biological activity, which refers to high antioxidant activity and high ACE inhibitory activity. Specifically, its DPPH free radical scavenging rate can reach 55.65% to 60.12%, and its ACE inhibitory activity can reach 75.34% to 79.25%. It includes 19 ACE inhibitory peptides, 20 antioxidant peptides, 11 DPP-IV inhibitory peptides and 9 antibacterial peptides, etc., with rich types and contents, and at the same time has better sensory organs and flavor.

[0076] The present application is further described below by specific examples. When the examples give numerical ranges, it should be understood that, unless otherwise specified in the present application, the two endpoints of each numerical range and any numerical value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as those commonly understood by those skilled in the art. In addition to the specific methods, equipment, and materials used in the examples, according to the technical staff of the present art's grasp of the prior art and the records of the present application, any methods, equipment, and materials of the prior art similar or equivalent to the methods, equipment, and materials described in the examples of the present application can also be used to implement the present application. Unless otherwise specified, the instruments, reagents, and materials used in the examples can be obtained by conventional means.

[0077] Preparation of Monascus filtrate: Take a small amount of Monascus M.CJ233 mycelium and inoculate it into PDB medium, culture it at 170r / min and 32℃ for 7 days, filter it with sterile absorbent cotton, and the live bacteria content of the filtrate is about 10 6CFU / L. The filtrate was stored at room temperature and prepared immediately before use.

[0078] Example 1

[0079] This embodiment provides a monascus cheese with high antioxidant and ACE inhibitory activities and a preparation method thereof.

[0080] (1) Raw milk and cream were weighed and standardized so that the mass ratio of fat to protein was 1.5:1, and the mixed materials were stirred at 400 rpm for 50 min.

[0081] (2) Pasteurize the material at 68°C / 25s and cool the material to 35°C.

[0082] (3) Inoculate the lactic acid bacteria starter at an inoculum rate of 10 U / 100 L, inoculate the filtered bacterial liquid of Monascus at an inoculum rate of 10 mL / 10 kg, stir at 100 rpm for 3 min, and ferment at 35° C. for 2 h.

[0083] (4) When the pH of the fermentation reaches 6.3, 0.05 g / 10 kg of rennet is added and the milk is allowed to curdle for 60 min. The milk is then cut into 2 × 2 × 2 cm pieces, stirred for 30 s, and allowed to stand for 1 min. This process is repeated three times to drain the whey.

[0084] (5) Add the curd to the mold and turn it over every 45 minutes for about 3 hours at a temperature of 22°C.

[0085] (6) Soaking the formed cheese completely in 16% sterile saline for 60 min;

[0086] (7) refers to placing the cheese after salting back into the mold and leaving it to air-dry at 14°C for 14 hours.

[0087] (8) The cheese that has been air-dried is transferred to a maturation container; the maturation conditions are set to first mature in a constant temperature and humidity incubator at 28°C and 50% humidity for 8 days, and then transferred to an incubator at 15°C and 90% humidity for maturation until 27 days; during this period, the maturation container is replaced irregularly.

[0088] Prepared cheese such as Figure 1 shown.

[0089] Example 2

[0090] This embodiment provides a monascus cheese with high antioxidant and ACE inhibitory activities and a preparation method thereof.

[0091] (1) Raw milk and cream were weighed and standardized so that the mass ratio of fat to protein was 1.6:1, and the mixed materials were stirred at 500 rpm for 40 min.

[0092] (2) Pasteurize the material at 70°C / 20s and cool the material to 34°C.

[0093] (3) Inoculate the lactic acid bacteria starter at an inoculum rate of 11 U / 100 L and inoculate the filtered bacterial liquid of Monascus at an inoculum rate of 11 mL / 10 kg, stir at 200 rpm for 4 min, and ferment at 37° C. for 2 h.

[0094] (4) When the pH of the fermentation reaches 6.3, 0.05 g / 10 kg of rennet is added and the milk is allowed to curdle for 50 min. The milk is then cut into 2 × 2 × 2 cm pieces, stirred for 35 s, allowed to stand for 1 min, and repeated three times to drain the whey.

[0095] (5) Add the curd to the mold and turn it over every 45 minutes for about 3.5 hours at a temperature of 20°C.

[0096] (6) Soaking the formed cheese completely in 18% sterile saline for 45 minutes;

[0097] (7) refers to placing the cheese after salting back into the mold and leaving it to air-dry at 15°C for 13 hours.

[0098] (8) The cheese that has been air-dried is transferred to a maturation container; the maturation conditions are set to first mature in a constant temperature and humidity incubator at 30°C and a humidity of 55% for 9 days, and then transferred to an incubator at 15°C and a humidity of 90% to mature for 25 days; during this period, the maturation container is replaced irregularly.

[0099] Example 3

[0100] This embodiment provides a monascus cheese with high antioxidant and ACE inhibitory activities and a preparation method thereof.

[0101] (1) Raw milk and cream were weighed and standardized so that the mass ratio of fat to protein was 1.7:1, and the mixed materials were stirred at 600 rpm for 30 min.

[0102] (2) Pasteurize the material at 72°C / 20s and cool the material to 35°C.

[0103] (3) Inoculate the lactic acid bacteria starter at an inoculum rate of 12 U / 100 L, inoculate the filtered bacterial liquid of Monascus at an inoculum rate of 12 mL / 10 kg, stir at 300 rpm for 3 min, and ferment at 35° C. for 2 h.

[0104] (4) When the pH of the fermentation reaches 6.4, 0.05 g / 10 kg of rennet is added and the milk is allowed to curdle for 45 min. The milk is then cut into 2 × 2 × 2 cm pieces, stirred for 40 s, allowed to stand for 1.5 min, and repeated 4 times to drain the whey.

[0105] (5) Add the curd quickly to the mold and turn it over every 45 minutes for about 4 hours at a temperature of 18°C.

[0106] (6) Soaking the formed cheese completely in 20% sterile saline for 30 min;

[0107] (7) refers to placing the cheese after salting back into the mold and leaving it to air-dry at 16°C for 12 hours.

[0108] (8) The cheese is transferred to a ripening container after being air-dried; the ripening conditions are set to first be ripened in a constant temperature and humidity incubator at 32°C and a humidity of 60% for 10 days, and then transferred to an incubator at 12°C and a humidity of 90% to mature for 23 days; the ripening container is replaced irregularly during this period.

[0109] Comparative Example 1

[0110] In this comparative example, except that the ripening time is 30°C for 3 days and then transferred to 15°C for 25 days, the remaining steps are the same as those of Example 2. The cheese prepared is as follows Figure 2 shown.

[0111] Comparative Example 2

[0112] This comparative example is the same as Example 2 except that the ripening time is 30°C for 3 days and then transferred to 15°C for 35 days.

[0113] Comparative Example 3

[0114] This comparative example has the same steps as those of Example 2 except that the ripening time is 12 days at 30°C and then 25 days at 15°C.

[0115] Comparative Example 4

[0116] This comparative example is the same as Example 2 except that the ripening time is 9 days at 30°C and then transferred to 15°C to ripen for 35 days.

[0117] Example 4 Sensory Evaluation

[0118] According to the national standards GB / T10221-2021 and GB5420-2021, the sensory evaluation standards for Monascus cheese were comprehensively formulated, and sensory evaluations were carried out on Examples 1, 2, and 3 of the Monascus cheese of the present application and Comparative Examples 1, 2, 3, and 4.

[0119] The tasting panel selected 20 professionals (10 men and 10 women) with experience in sensory evaluation of dairy products. The evaluation criteria included taste, smell, color, texture and overall acceptance, with each indicator scored 10 points (1-2 points for poor, 3-4 points for average, 5-6 points for good, 7-8 points for very good, and 9-10 points for excellent). Before tasting, the participants cleaned their palates with purified water and randomly selected samples for scoring. The results are shown in Table 1.

[0120] Table 1 Sensory evaluation results of Monascus cheese prepared in Examples 1-3 and Comparative Examples 1-4

[0121]

[0122] As can be seen from Table 1, the sensory evaluation results of the Monascus cheese prepared in Examples 1-3 are higher than those of the Monascus cheese prepared in Comparative Example 1 in terms of taste, smell, color and overall acceptance. Compared with Comparative Example 1, the Monascus cheese prepared by the maturation process of the present application has a more complete growth of Monascus in the early stage of maturation, resulting in more intense biochemical reactions such as protein metabolism and fat metabolism during the same maturation period, which is conducive to the formation of characteristic taste and flavor. Compared with the 35-day maturation period of Comparative Example 2, the present application only takes about 25 days to achieve the same maturation effect, which shortens the maturation time to a certain extent. For Comparative Examples 3 and 4, a longer high-temperature maturation period and a longer total maturation time will cause the Monascus cheese to be over-matured, resulting in an increase in undesirable flavors such as moldy smell, and a soft texture, which is not conducive to the formation of good sensory quality. In addition, the present application achieves that the Monascus cheese does not need to be divided into small pieces and can achieve better maturity and sensory quality in a shorter time, and the production efficiency is effectively improved.

[0123] Example 5 Determination of relative contents of soluble nitrogen (pH 4.6-SN) and trichloroacetic acid soluble nitrogen (TCA-SN)

[0124] In this example, the maturity of the Monascus cheeses prepared in Examples 1-3 and Comparative Example 1 was determined by measuring the relative contents of pH 4.6 soluble nitrogen (pH 4.6-SN) and trichloroacetic acid soluble nitrogen (TCA-SN).

[0125] Determination of relative content of pH 4.6-SN: Weigh about 3g of cheese sample and dissolve it in 27mL of acetate buffer solution with a pH value of 4.6. After grinding thoroughly, centrifuge at 4000r / min for 20min, then take 5mL of supernatant and transfer it to the digestion tube for Kjeldahl determination. The result is expressed as the proportion of total nitrogen in cheese. Determination of relative content of TCA-SN: Take 3g of cheese, add 27mL of 12% TCA solution by mass, mix well and let stand for 1h, centrifuge at 4℃ and 4000r / min for 20min, take 5mL of supernatant and transfer it to the digestion bottle for Kjeldahl determination. The result is expressed as the proportion of TCA-SN in total nitrogen in cheese. The results are shown in Table 2.

[0126] Table 2 Determination of relative contents of pH 4.6-SN and TCA-SN in Monascus cheese prepared in Examples 1-3 and Comparative Examples 1-4

[0127]

[0128] As can be seen from Table 2, the relative contents of pH4.6-SN and TCA-SN in Examples 1-3 are significantly higher than those in Comparative Example 1. These two indicators represent the degree of hydrolysis of protein in Monascus cheese. The larger the value, the stronger the protein hydrolysis, the more short peptides and free amino acids are generated, and the higher the maturity. Since most of the active peptides come from short peptides less than 3kDa, the increase in maturity also provides more possibilities for the generation of active peptides. Comparative Example 2 requires a longer maturation period to reach the maturity of the Monascus cheese prepared by the maturation process of the present application. The relative contents of pH4.6-SN and TCA-SN in Comparative Examples 3 and 4 exceed those in Examples 1-3, but over-maturation has a strong negative impact on Monascus cheese, which is not conducive to product quality.

[0129] Example 6 Biological Activity Assay

[0130] In this example, the Monascus cheeses prepared in Examples 1-3 and Comparative Example 1 were subjected to biological activity assays, including DPPH free radical scavenging rate and angiotensin converting enzyme (ACE) inhibitory activity assays.

[0131] Specifically, the preparation of the crude mixture of Monascus cheese active peptides is as follows: add an appropriate amount of deionized water to the cheese sample, treat it in a 40°C water bath for 30 minutes, and then homogenize it for 3-4 minutes. Centrifuge the homogenate (4°C, 8000rpm, 20min) to remove the upper fat. The supernatant is filtered through Whatman No.41 filter paper, 0.22μm aqueous phase filter membrane, 10kDa and 3kDa ultrafiltration membranes, and then freeze-dried to obtain a freeze-dried powder of the crude mixture of active peptides.

[0132] Determination method of DPPH free radical scavenging rate: 0.1mL, 20mg / mL cheese freeze-dried powder sample and 3.9mL, 60μmol / L DPPH-methanol solution were mixed evenly, reacted at room temperature in the dark for 45min, and then the absorbance A1 at 517nm was measured. The control group used distilled water instead of the sample, and the result was A0 to evaluate the DPPH free radical scavenging ability. The result is expressed as a scavenging rate, which is calculated as shown in formula (1):

[0133] DPPH free radical scavenging rate = (A0-A1) / A0×100% (1)

[0134] Method for determining ACE inhibitory activity: 20 μL of ACE (0.1 U / mL) was aspirated into a transparent 96-well plate. Then, 40 μL of 80 mmol / L HEPES buffer (pH 8.3) and lyophilized powder solution (5 mg / mL) were added to the control well and sample well, respectively. Finally, 50 μL of preheated 1 mmol / L FAPGG was added to each well and mixed immediately. The initial absorbance of the control well and sample well was measured at a wavelength of 340 nm (A1 and B1) using an ELISA reader, and the absorbance was measured again (A2 and B2) after being kept in the dark at 37°C for 30 min. The results were expressed as ACE inhibition rate, which was calculated as shown in formula (2):.

[0135] ACE inhibition rate = (AB) / A × 100% (2)

[0136] Where: A is the absorbance reduction value of the control well, i.e. A1-A2; B is the absorbance reduction value of the sample well, i.e. B1-B2.

[0137] Table 3 Analysis of biological activity of Monascus cheese prepared in Examples 1-3 and Comparative Examples 1-4

[0138]

[0139] As shown in Table 3, the DPPH free radical scavenging ability and ACE inhibitory ability of Examples 1-3 are significantly higher than those of Comparative Examples 1-2. Compared with Comparative Examples 3-4, which also have good life activities, Examples 1-3 have better cheese sensory quality. The mature process of the present application is conducive to enhancing the antioxidant and hypotensive activity of the product, improving the product value, and meeting the diverse health needs of consumers.

[0140] Liquid chromatography-tandem mass spectrometry (LC-MS / MS) was used to identify the functional active peptides of Examples 1-3. The specific results are shown in Table 4.

[0141] Table 4 Identification of functional active peptides of Examples 1-3

[0142]

[0143]

[0144] As can be seen from Table 4, Examples 1-3 contain a variety of functional active peptides, including 19 ACE inhibitory peptides, 20 antioxidant peptides, 11 DPP-IV inhibitory peptides and 9 antimicrobial peptides, etc., and the types are also very rich.

[0145] The above embodiments are merely illustrative of the principles and effects of the present application and are not intended to limit the present application. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by a person of ordinary skill in the art without departing from the spirit and technical ideas disclosed in the present application shall still be covered by the claims of the present application.

Claims

1. A method for ripening monascus cheese with high biological activity, comprising ripening the shaped cheese under the following conditions: the shaped cheese is first ripened at 28-32°C and 50-60% humidity for 8-10 days, and then transferred to 12-15°C and 80-90% humidity for 23-27 days.

2. The maturation method according to claim 1, characterized in that The method for preparing the shaped cheese comprises: using Monascus filtered bacterial liquid for fermentation; preferably, the preservation number of Monascus in the Monascus filtered bacterial liquid is CGMCC No.18563.

3. A method for preparing Monascus cheese with high biological activity, comprising obtaining shaped cheese, and then maturing the shaped cheese using the Monascus cheese maturation method according to any one of claims 1 to 2 to obtain the Monascus cheese with high biological activity.

4. The preparation method according to claim 3, characterized in that: The method for obtaining the shaped cheese comprises the following steps: raw material pretreatment, fermentation, curdling, and shaping.

5. The preparation method according to claim 4, characterized in that: The method for obtaining the formed cheese comprises the following steps: 1) Raw material pretreatment: standardize the raw milk and cream, perform the first stirring, sterilize and cool to obtain the pretreated product; 2) fermentation: inoculating the pretreated product with a lactic acid bacteria starter and a Monascus filtered bacterial liquid, stirring for a second time, and fermenting to obtain a fermented product; 3) Curdling: the fermented product is mixed with rennet, and the milk is curdled to obtain curd; 4) Molding process: molding the curd block to obtain molded cheese.

6. The preparation method according to claim 5, characterized in that: In step 1), the method further comprises any one or more of the following features: 11) The standardization is a mixture obtained by mixing raw milk and cream, wherein the mass ratio of fat to protein in the mixture is 1.5 to 1.7:1; 12) The first stirring speed is 400-600 rpm, and the first stirring time is 30-50 min; 13) The sterilization is performed by pasteurization; preferably, the sterilization temperature is 68-72° C., and the sterilization time is 15-25 seconds; 14) The cooling is cooling to 32-35°C.

7. The preparation method according to claim 5, characterized in that: In step 2), the method further has any one or more of the following characteristics: 21) The lactic acid bacteria starter is selected from at least one of Flora Danica starter or STI-13 starter; preferably, the addition amount of the lactic acid bacteria starter is 10-12U / 100L pretreated material; 22) The amount of the Monascus filtered bacterial solution added is 10-12 mL / 10 kg of the pretreated material; 23) The second stirring speed is 100 to 300 rpm, and the second stirring time is 3 to 5 minutes; 24) The fermentation temperature is 35-39° C., and the fermentation time is 1.5-2 hours.

8. The preparation method according to claim 5, characterized in that: In step 3), the method further comprises any one or more of the following features: 31) The pH of the fermentation product when mixed with rennet is 6.3-6.4; 32) The amount of rennet added is 0.05-0.08 g / 10 kg of fermentation product; 33) The coagulation time is 45 to 60 minutes.

9. The preparation method according to claim 5, characterized in that: In step 4), the molding process includes cutting the curd, stirring for the third time, molding, turning over, salting, and drying; Preferably, the molding process further comprises any one or more of the following features: a) The third stirring is stirring for 30 to 40 seconds, standing for 1 to 1.5 minutes, and repeated 3 to 4 times; b) the temperature of the turning treatment is 18-22° C., the turning treatment time is 3-4 hours, and the turning treatment is performed every 45-50 minutes; c) the salting is performed by soaking the turned curd in 16-20% sterile saline for 30-60 minutes; d) The drying step is to place the salted curd at 14-16° C. for 10-14 hours.

10. Use of the ripening method according to any one of claims 1 to 2, or the preparation method according to any one of claims 3 to 9, in improving the biological activity of Monascus cheese; preferably, the biological activity includes antioxidant activity and / or ACE inhibitory activity.

11. A Monascus cheese, obtained by ripening shaped cheese by the ripening method according to any one of claims 1 to 2, or prepared by the preparation method according to any one of claims 3 to 9.

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