A method for fermenting fresh corn and its application in product processing

Abstract

The present invention provides a method for fermenting fresh corn and its application in product processing. The method comprises the following steps: S1: harvesting and processing fresh corn cobs to obtain harvested fresh corn cobs; S2: processing the harvested fresh corn cobs to obtain fresh corn crumbs; S3: preparing a fresh corn culture medium with the fresh corn crumbs; S4: culturing Ganoderma lucidum strains to obtain Ganoderma lucidum fermentation seeds; S5: inoculating the Ganoderma lucidum fermentation seeds into the fresh corn culture medium to obtain fermented fresh corn; and S6: drying and crushing the fermented fresh corn to obtain fermented fresh corn flour for use in product processing. The fermented fresh corn flour obtained by fermentation is rich in nutrients and has a high content of active substances. It has biological activities such as improving immunity, regulating blood sugar and blood lipids, and anti-oxidation. The fermented fresh corn flour is used in product processing to enrich the variety of processed products and meet consumer demand. The method provides an effective way to extend the fresh corn industry chain and the Ganoderma lucidum processing industry chain, and has broad application prospects.

Description

Technical Field

[0001] The invention belongs to the field of microbial fermentation in the field of biotechnology, and particularly relates to a fermentation method for fresh corn and application thereof in product processing. Background Art

[0002] Fresh corn, also known as fruit corn, refers to young, tender corn with a unique flavor and quality. It can be used as a vegetable, fruit, food, or feed. Compared to regular corn, it is sweeter, more glutinous, more tender, and more fragrant. It is categorized by quality into sweet corn, super sweet corn, sweet and sticky corn, and glutinous corn, while kernel color includes black, purple, yellow, white, and variegated colors. Fresh corn is rich in nutrients, with high levels of trace elements such as calcium, magnesium, and selenium, as well as vitamins and amino acids. Black and purple fresh corn are particularly rich in anthocyanins. Compared to regular corn, sticky corn has a thinner skin and no residue, and is higher in sugar, water-soluble protein, and salt-soluble protein. It is also rich in vitamins E, B1, B2, C, inositol, choline, and minerals.

[0003] Fresh corn has certain benefits in preventing cancer, slowing down blood vessel aging, and lowering blood cholesterol. It aligns with today's consumer philosophy of healthy eating, embracing antioxidants, whole grains, and balanced nutrition, making it a highly sought-after high-end food for modern urbanites. The cultivated area of fresh corn in my country has been rapidly increasing in recent years, and its consumption has also been rising year by year. However, since the edible portion of fresh corn consists of immature, tender kernels, their respiration and metabolism are vigorous after harvest, leading to rapid sugar conversion and prone to water loss and deterioration. Therefore, fresh corn must be quickly frozen or vacuum-packed after harvesting to prevent long-term storage or year-round supply. Currently, fresh corn consumption is primarily focused on fresh-ear sales and quick-freezing, with fresh corn processing still at a rudimentary stage. Due to factors such as production region, season, climate, and growing season, the market price of fresh corn fluctuates significantly, ranging from 2 to 6 yuan per kilogram. These significant price fluctuations pose significant challenges to the stable and healthy development of the fresh corn industry. At the same time, the only deep-processed fresh corn products on the market are corn juice, canned corn, etc. The product types are single and the varieties are few, which cannot meet the needs of consumers.

[0004] Yeast is a single-celled microorganism belonging to the fungi family of higher microorganisms. It can survive both in the presence and absence of oxygen and is a natural fermentation agent used in brewing and as a model organism for scientific research. Saccharomyces cerevisiae is a major yeast species commonly used in production and life, for example, in the fermentation of fruit wine, beer, and pasta products. Yeast can also be consumed by humans, such as in the form of dry yeast powder or tea yeast. Some yeast species possess unique metabolic pathways. For example, some strains of terrestrial Issaffron yeast have the ability to metabolize citric acid, which they can break down for cell growth and metabolism. During the citric acid decomposition process, they produce a wealth of metabolic intermediates that flow into pathways for the synthesis of sterols and fatty acids, providing important intermediate metabolites for the synthesis of certain active substances, such as triterpenes.

[0005] Lingzhi, a precious edible and medicinal fungus, is listed as a "substance traditionally used as both a food and a Chinese medicinal ingredient." Lingzhi contains a variety of nutrients and active substances, including proteins, amino acids, polysaccharides, peptides, triterpenes, taurine, adenosine, alkaloids, volatile oils, and mannitol. The two most important active substances are triterpenes and polysaccharides. Lingzhi has long been a highly regarded and valuable herb in traditional Chinese medicine, demonstrating numerous physiological benefits, including immunomodulation, anti-tumor properties, protection against radiation and chemotherapy damage, sedative properties, antidepressant properties, anti-epileptic properties, protection against Alzheimer's disease, anti-Parkinson's disease, protection against cardiac and cerebral ischemia, lipid regulation, blood pressure and blood sugar reduction, liver and kidney protection, anti-aging, and antiviral properties.

[0006] The edible and medicinal part of Ganoderma lucidum is the fruiting body, which is kidney-shaped, semicircular, or nearly circular. The cap and stipe are leathery, woody, or corky in texture, making them unsuitable for direct consumption. Active substances are typically extracted from the mushroom or consumed after undergoing cell wall cracking. Currently, Ganoderma lucidum production technology primarily relies on traditional solid-state cultivation, which is used for fruiting body formation and the extraction of key active substances. However, in my country, Ganoderma lucidum is primarily cultivated in a scattered manner, with limited large-scale cultivation and relatively traditional cultivation techniques. Furthermore, solid-state cultivation requires significant human and material resources, and the cultivation cycle is long and time-consuming. These unfavorable factors result in weak production capacity, long production cycles, and inconsistent quality of Ganoderma lucidum products. The market is limited in variety and variety, with most products sold in whole flowers, slices, spore powder, and extracts. These high prices limit public consumption of Ganoderma lucidum as a health food. Summary of the Invention

[0007] The present invention provides a fermentation method for fresh corn and its application in product processing. One purpose is to solve the problem of few types and single varieties of processed products using fresh corn as raw material, enrich the types of corn and related products, and meet consumer demand; the second purpose is to solve the problems of single Ganoderma lucidum products, unsuitable fruiting bodies for direct consumption, and high product prices; the third purpose is to significantly increase the content of Ganoderma lucidum triterpenes in fermented fresh corn, so that the processed products contain rich active substances of fresh corn and Ganoderma lucidum and have better biological activity. The fermented fresh corn obtained by the present invention is not only rich in corn nutrition and high content of Ganoderma lucidum active substances, especially Ganoderma lucidum triterpenes, so that the fermented fresh corn has the characteristics of rich and balanced nutrition and high content of active substances, but also has multiple biological activities such as anti-oxidation, anti-aging, improving body immunity, regulating blood sugar, blood lipids and blood pressure, protecting liver and kidney, etc.

[0008] The present invention is achieved through the following technical solutions.

[0009] A method for fermenting fresh corn and its application in product processing. To obtain the fermented fresh corn and apply it to product processing, the operation steps include: S1: harvesting and processing fresh corn cobs to obtain harvested fresh corn cobs, S2: processing the harvested fresh corn cobs to obtain fresh corn crumbs, S3: preparing a fresh corn culture medium with the fresh corn crumbs, S4: culturing Ganoderma lucidum strains to obtain Ganoderma lucidum fermentation seeds, S5: inoculating the Ganoderma lucidum fermentation seeds into the fresh corn culture medium to obtain fermented fresh corn through fermentation, and S6: drying and crushing the fermented fresh corn to obtain fermented fresh corn flour for application in product processing.

[0010] The fermented fresh corn flour obtained can be applied to the processing of various products. For example, the fermented fresh corn flour can be added to corn flour products to improve the nutritional value and functional activity of the corn flour products, while also enhancing the color, aroma, and taste of the corn flour products. The fermented fresh corn flour can be added to fresh corn flour to make the resulting product have the nutrition, taste, and function of fresh corn, while also having the nutrition, active substances, and functionality of Ganoderma lucidum. The fermented fresh corn flour can be added to rice flour to produce corresponding products. The active substances in the fermented fresh corn flour can be extracted and further processed to obtain products. The fermented fresh corn flour can be added to and applied to the processing of other products, etc.

[0011] The fresh corn includes one or a mixture of sweet corn, glutinous corn, and sweet and glutinous corn.

[0012] The Ganoderma lucidum is red Ganoderma lucidum or purple Ganoderma sinense.

[0013] Specifically, the operation steps are as follows:

[0014] S1: Harvesting and processing fresh corn cobs to obtain fresh corn cobs after harvest

[0015] The picking period of fresh corn cobs is 3-7 days later than the normal harvest period in order to accumulate more dry matter. After picking the fresh corn cobs, the husks are peeled off and the surface is rinsed with water to remove residual husks, corn silk and other impurities and debris. After being spread out in a dry, ventilated and clean place at room temperature for 10-15 hours, the 3-5 cm part at the tip of the fresh corn cob is removed to obtain the fresh corn cob after harvest.

[0016] S2: Processing of fresh corn cobs after harvest to obtain fresh corn crumbs

[0017] The harvested fresh corn cobs obtained in S1 are steamed with 100°C steam for 10-15 minutes, taken out, spread out in a clean and ventilated place to cool to room temperature, threshed to obtain fresh corn kernels, and then crushed. The specific operation is to place the fresh corn kernels in a wall breaking machine, operate it at a medium or low gear for 8-15 seconds, and obtain broken fresh corn kernels. The broken fresh corn kernels are placed in a clean blast drying oven at 45-55°C and dried until the moisture content of the broken fresh corn kernels is 35-40%, thereby obtaining the fresh corn crumbs.

[0018] S3: Fresh corn crushed to prepare fresh corn culture medium

[0019] The fresh corn culture medium comprises fresh corn shreds, carrot shreds, a terrestrial Issaffine wet culture slurry, riboflavin, and nicotinamide. The specific preparation method is as follows: 60-80 mg of riboflavin and 30-50 mg of nicotinamide are weighed, added to 30-70 g of the terrestrial Issaffine wet culture slurry, and stirred thoroughly; 150-200 g of carrot shreds are added to the slurry, and stirred thoroughly again to mix thoroughly; then, the slurry is added to 1000-1500 g of the fresh corn shreds obtained in step S2, stirred thoroughly to mix thoroughly, and packaged into 100-250 g per 500 mL Erlenmeyer flask, sterilized at 115°C for 15 minutes, and cooled to room temperature to obtain the fresh corn culture medium.

[0020] The carrot shreds preparation method comprises removing impurities from commercially available carrots, washing them, draining them, cutting them into 1-2 cm chunks, and crushing the chunks to obtain crushed carrot chunks. Specifically, the carrot chunks are placed in a wall-breaking machine and operated at a medium-low setting for 10-20 seconds to obtain the crushed carrot chunks. The crushed carrot chunks are then dried in a clean forced air drying oven at 45-55°C until the moisture content of the crushed carrot chunks reaches 35-40%, thereby obtaining the carrot shreds.

[0021] The terrestrial Issaffine wet bacterial mud is obtained by inoculating terrestrial Issaffine seed liquid into a liquid citric acid culture medium, culturing for 24-28 hours, and then centrifuging the resulting wet bacterial mud.

[0022] The terrestrial yeast is Issatchenkia terricola WJL-G4, deposited at the General Microbiology Center of the China General Culture Collection Administration, with the deposit number: CGMCC No. 18712. The liquid citric acid culture medium contains 10-20 g of citric acid, 0.1-0.5 g of MgSO4, and 5-15 g of yeast extract per liter of liquid citric acid culture medium. The seed solution of the terrestrial yeast is obtained by inoculating a loopful of Issatchenkia terricola WJL-G4 culture stored on a slant into the liquid citric acid culture medium. The fermentation is carried out at a temperature of 22-28°C, a rotation speed of 120-240 rpm, and a liquid volume ratio of 12-20% (v / v), for 12-18 hours. The culture conditions for obtaining the terrestrial Issaffine wet slurry are: an inoculum volume of 3-7% (v / v), a temperature of 22-28°C, a rotation speed of 120-240 rpm, a liquid volume ratio of 10-25%, and a fermentation time of 24-48 hours. The centrifugation conditions are 8000 rpm for 15 minutes.

[0023] The citric acid, MgSO4, lutein and nicotinamide, i.e. the raw materials used for fermentation, are all food grade, and the tools and equipment involved are all food grade.

[0024] S4: Cultivate Ganoderma lucidum strains and obtain fermented Ganoderma lucidum seeds

[0025] Take a piece of the Ganoderma lucidum slant culture stored in a 4°C refrigerator, transfer it to a Ganoderma lucidum solid plate culture medium, and culture it at a constant temperature of 22-28°C for 3-7 days to obtain first-class Ganoderma lucidum seeds. Cut a piece of the first-class Ganoderma lucidum seeds, transfer it to a Ganoderma lucidum solid plate culture medium again, and culture it at a constant temperature of 22-28°C for 3-7 days to obtain the Ganoderma lucidum fermented seeds.

[0026] The Ganoderma lucidum solid plate culture medium is composed of 8-15 g of Issaffine terrestrial wet culture slurry, 15-25 g of glucose, 150-200 g of potato, 0.1-0.4 g of MgSO4, and 20-25 g of agar per liter, sterilized at 121°C for 15 minutes. The amount of Ganoderma lucidum solid plate culture medium used is 12-20 mL per plate, which is then inverted after cooling and solidification.

[0027] The potatoes need to be cut into pieces, added with water and boiled for 30 minutes, then filtered and the filtrate is used.

[0028] S5: Inoculate fresh corn culture medium with Ganoderma lucidum fermentation seeds and ferment to obtain fermented fresh corn

[0029] The fermented Ganoderma lucidum seeds obtained in step S4 are inoculated into the fresh corn culture medium obtained in step S3 under sterile conditions, stirred evenly with a sterile glass rod, and then cultured in an incubator at 22-28° C. for 6-15 days to obtain the fermented fresh corn.

[0030] The inoculation amount of the Ganoderma lucidum fermentation seeds is 3-6 pieces of the Ganoderma lucidum fermentation seeds with a size of 1.5-2 cm × 1.5-2 cm cut into each bottle of the fresh corn culture medium, and after inoculation, the seeds are stirred evenly using a sterile glass rod.

[0031] S6: Dry and crush the fermented fresh corn to obtain fermented fresh corn flour for use in product processing

[0032] The fermented fresh corn obtained in step S5 is freeze-dried or dried at 45-55° C., and crushed to obtain the fermented fresh corn flour.

[0033] The fermented fresh corn flour can be used in product processing, either directly processed into products or used in the processing of corn products or related products. For example, it can be added to corn flour to impart the active substances and nutritional value of Ganoderma lucidum to the corn flour, thereby increasing the economic added value of corn processed products. Alternatively, it can be added to fresh corn flour to enhance the nutritional and functional activity of fresh corn processed products. Alternatively, it can be used as a main ingredient or auxiliary ingredient in the processing of other products. Alternatively, it can be used to extract Ganoderma lucidum active substances, which can be further processed into health foods, health products, cosmetics, or pharmaceutical products.

[0034] Advantages of the present invention

[0035] The fermentation method of the present invention has the advantages that the fermentation medium is naturally easy to obtain, cheap, and has a simple processing method. The fermentation conditions are mild, the production efficiency is high, the fermentation does not generate waste, and it is green and environmentally friendly. The fermented fresh corn flour obtained by fermentation is rich in nutrition and high in active substance content. It has the nutrition of fresh corn and Ganoderma lucidum and has the advantages of improving the body's immunity, adjusting blood sugar and blood lipids, anti-oxidation, anti-aging, protecting the liver and kidneys and other biological activities. The obtained fermented fresh corn flour can be widely used in product processing or food production, can enrich the variety of corn deep-processing products, meet consumer demand, and can also be added to other products, or developed into pharmaceutical products after active substance extraction. Therefore, the fermentation method and application provided by the present invention provide an effective way to extend the fresh corn industry chain and the Ganoderma lucidum processing industry chain, and the application prospect is very broad. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The standard curve of the linear relationship between liquid fermentation mycelium biomass and ergosterol.

[0037] Figure 2 The influence of various compound ingredients on fermentation effect.

[0038] Figure 3 The effect of the addition ratio of compound ingredients on the fermentation effect.

[0039] Figure 4 The effects of various external nitrogen sources on fermentation performance.

[0040] Figure 5 The effect of the addition ratio of external nitrogen source on the fermentation effect.

[0041] Figure 6 The effects of various growth factors on fermentation effects.

[0042] Figure 7 The effect of growth factor addition on fermentation effect.

[0043] Figure 8 The effect of culture medium water content on fermentation effect.

[0044] Figure 9 The effect of culture temperature on fermentation effect.

[0045] Figure 10 The effect of culture medium loading amount on fermentation effect.

[0046] Figure 11 The effect of inoculation amount on fermentation effect.

[0047] Figure 12 The effect of culture time on fermentation effect.

[0048] Figure 13 Observation diagram of fermented fresh corn obtained for Examples 1-3.

[0049] Figure 14 These are the results of triterpene content and Ganoderma mycelium biomass determination in Examples 1-3.

[0050] Figure 15 It is fermented fresh corn flour obtained after freeze-drying or drying and crushing. DETAILED DESCRIPTION

[0051] The technical solution of the present invention is further described below with reference to specific embodiments, but the present invention is not limited thereto.

[0052] Example 1

[0053] A method for fermenting fresh corn and its application in product processing, the specific implementation plan is as follows:

[0054] S1: Harvesting and processing fresh corn cobs to obtain fresh corn cobs after harvest

[0055] The picking period of fresh corn cobs is 7 days later than the normal harvest period. After picking, the husks of the fresh corn cobs were peeled off and the surface was rinsed with clean water to remove the remaining husks, corn silk and other impurities and debris. After being spread out in a cool, dry and clean place for 10 hours, the top 3 cm of the fresh corn cobs were removed to obtain the fresh corn cobs after harvest.

[0056] S2: Processing of fresh corn cobs after harvest to obtain fresh corn crumbs

[0057] The fresh corn cobs obtained in S1 were steamed at 100°C for 10 min, cooled to room temperature, and then threshed to obtain fresh corn kernels. The fresh corn kernels were placed in a wall-breaking machine and operated at gear L5 among medium-low settings for 10 s to obtain broken fresh corn kernels. The fresh corn kernels were then placed in a 45°C forced air drying oven to a moisture content of 40% to obtain fresh corn crumbs.

[0058] S3: Fresh corn crushed fresh corn culture medium

[0059] The ingredients of the fresh corn culture medium include fresh corn shreds, carrot shreds, terrestrial Issatch yeast wet culture mud, food grade riboflavin and food grade nicotinamide.

[0060] Commercially purchased carrots were cleaned, washed, and cut into 1 cm chunks. The chunks were placed in a blender at setting L6 (medium-low) for 20 seconds to obtain shredded carrot chunks. The shredded carrot chunks were then dried in a clean, forced-air drying oven at 55°C until the moisture content reached 40%. This resulted in shredded carrots.

[0061] A loopful of Issatchenkia terricola WJL-G4 strains stored on a slant was inoculated into a liquid citric acid medium containing 20 g / L food-grade citric acid, 0.1 g / L food-grade MgSO₄, and 5 g / L food-grade yeast extract. Fermentation was performed at 28°C, 140 rpm, and a 12% (v / v) liquid-to-volume ratio for 12 h to obtain the I. terricola seed solution. A 3% (v / v) inoculum of the I. terricola seed solution was inoculated into a 15% (v / v) liquid citric acid medium. Fermentation was performed at 28°C, 140 rpm, and 48 h. The culture was then centrifuged at 8000 rpm for 15 min to obtain the I. terricola wet slurry.

[0062] Weigh 60 mg of food-grade riboflavin and 30 mg of food-grade nicotinamide, add them to 30 g of Issippa terrestris wet culture slurry, and stir thoroughly to mix; then add 150 g of chopped carrots and stir thoroughly to mix; then add 1000 g of the fresh corn shreds obtained in step S2 and stir thoroughly to mix; divide the mixture into 500 mL Erlenmeyer flasks, add 200 g each, sterilize at 115°C for 15 min, and cool to room temperature to obtain a fresh corn culture medium.

[0063] S4: Cultivate Ganoderma lucidum strains and obtain fermented red Ganoderma lucidum seeds

[0064] 200 g of peeled potatoes were added to 800 mL of water and boiled for 30 minutes. The filtrate was then filtered to obtain a filtrate. 8 g of the terrestrial Issaffine wet slurry obtained in step S3, 15 g of food-grade glucose, 0.1 g of food-grade MgSO₄, and 20 g of food-grade agar powder were added to the filtrate. The volume was adjusted to 1000 mL and stirred evenly. The slurry was sterilized at 121°C for 15 minutes. After adequate cooling, the slurry was plated to obtain a solid plate culture medium for Ganoderma lucidum. A piece of the red Ganoderma lucidum slant culture stored in a 4°C refrigerator was selected and transferred to the solid plate culture medium for Ganoderma lucidum. After constant temperature cultivation at 28°C for 7 days, a first-grade red Ganoderma lucidum seed was obtained. A piece of the first-grade red Ganoderma lucidum seed was cut and transferred again to the solid plate culture medium for Ganoderma lucidum. After constant temperature cultivation at 28°C for 7 days, the fermented red Ganoderma lucidum seed was obtained.

[0065] S5: Inoculate the fresh corn culture medium with Ganoderma lucidum fermentation seeds and ferment to obtain fermented fresh corn

[0066] The fermented red Ganoderma lucidum seeds obtained in step S4 were cut into 6 pieces of 1.5 cm × 1.5 cm under sterile conditions and inoculated into 1 bottle of fresh corn culture medium obtained in step S3, with 6 pieces inoculated into each bottle of fresh corn culture medium. The seeds were stirred evenly with a sterile glass rod and then cultured in an incubator at 26°C for 6 days to obtain fermented fresh corn.

[0067] S6: Dry and crush the fermented fresh corn to obtain fermented fresh corn flour for use in product processing

[0068] The fermented fresh corn obtained in step S5 is freeze-dried and crushed to obtain the fermented fresh corn flour.

[0069] The fermented fresh corn flour is added to corn flour at a mass ratio of 10 parts of the fermented fresh corn flour to every 100 parts of corn flour to obtain a corn flour product.

[0070] Example 2

[0071] A method for fermenting fresh corn and its application in product processing, the specific implementation plan is as follows:

[0072] S1: Harvesting and processing fresh corn cobs to obtain fresh corn cobs after harvest

[0073] The picking period of fresh corn cobs is 3 days later than the normal harvest period. After picking, the husks of the fresh corn cobs were peeled off and the surface was rinsed with water to remove impurities and debris such as residual husks and corn silk. After being spread out in a cool, dry, ventilated and clean place for 12 hours, the top 5 cm of the fresh corn cobs were removed to obtain the fresh corn cobs.

[0074] S2: Processing of fresh corn cobs after harvest to obtain fresh corn crumbs

[0075] The harvested fresh corn cobs obtained in S1 were steamed at 100°C for 15 minutes, cooled to room temperature, and threshed after the surface moisture evaporated to obtain fresh corn kernels. The fresh corn kernels were placed in a wall breaking machine and operated at medium-low gear L6 for 15 seconds to obtain broken fresh corn kernels, which were then placed in a 45°C forced air drying oven to a moisture content of 40% to obtain fresh corn crumbs.

[0076] S3: Fresh corn crushed fresh corn culture medium

[0077] The ingredients of the fresh corn culture medium include fresh corn shreds, carrot shreds, terrestrial Issatch yeast wet culture paste, riboflavin and nicotinamide.

[0078] Commercially purchased carrots were cleaned, washed, and cut into 2 cm chunks. The chunks were placed in a blender at setting L5 (medium-low) for 15 seconds to obtain shredded carrot chunks. The shredded carrot chunks were then dried in a clean, forced-air drying oven at 45°C until the moisture content reached 35%. This resulted in shredded carrots.

[0079] A loopful of Issatchenkia terricola WJL-G4 strains stored on a slant was inoculated into a liquid citric acid medium containing 20 g / L food-grade citric acid, 0.1 g / L food-grade MgSO₄, and 5 g / L food-grade yeast extract. Fermentation was performed at 28°C, 140 rpm, and a 12% (v / v) liquid-to-volume ratio for 18 h to obtain the I. terricola seed solution. A 5% (v / v) inoculum of the I. terricola seed solution was inoculated into a 20% (v / v) liquid citric acid medium. Fermentation was performed at 28°C and 140 rpm for 48 h, followed by centrifugation at 8000 rpm for 15 min to obtain the I. terricola wet slurry.

[0080] Weigh 75 mg of food-grade riboflavin and 50 mg of food-grade nicotinamide, add them to 70 g of Issippa terrestris wet culture slurry, and stir thoroughly to mix; then add 200 g of chopped carrots to the slurry and stir thoroughly to mix; then add all of the slurry to 1500 g of fresh corn shreds obtained in step S2 and stir thoroughly to mix; divide the slurry into 500 mL triangular bottles, add 250 g each, sterilize at 115°C for 15 min, and cool to room temperature to obtain a fresh corn culture medium.

[0081] S4: Cultivate purple Ganoderma lucidum strains and obtain purple Ganoderma lucidum fermented seeds

[0082] Take a piece of the purple Ganoderma lucidum slant culture stored in a 4°C refrigerator, transfer it to a Ganoderma lucidum solid plate culture medium, and culture it at a constant temperature of 25°C for 3 days to obtain the first-level purple Ganoderma lucidum seeds. Cut one piece of the first-level purple Ganoderma lucidum seeds, transfer it to a Ganoderma lucidum solid plate culture medium again, and culture it at a constant temperature of 25°C for 3 days to obtain the purple Ganoderma lucidum fermented seeds.

[0083] The composition of the Ganoderma lucidum solid plate culture medium is that each liter contains 15 g of the terrestrial Issaffine wet bacterial mud, 25 g of glucose, 150 g of potato, 0.4 g of MgSO4, and 25 g of agar; the preparation method is: add an appropriate amount of water to the potato and boil it for half an hour, then filter the filtrate, add other substances, adjust the volume to 1000 mL, and sterilize at 121°C for 15 minutes.

[0084] S5: Inoculate fresh corn culture medium with Ganoderma lucidum fermentation seeds and ferment to obtain fermented fresh corn

[0085] Cut four pieces of 2 cm × 2 cm in size from the fermented Ganoderma lucidum seeds obtained in step S4, and inoculate all of them into one bottle of the fresh corn culture medium obtained in step S3 under sterile conditions. A total of four bottles were inoculated, and each bottle was stirred evenly with a sterile glass rod. The culture was then incubated in a 22°C incubator for 12 days to obtain the fermented fresh corn.

[0086] S6: Dry and crush the fermented fresh corn to obtain fermented fresh corn flour for use in product processing

[0087] The fermented fresh corn obtained in step S5 is dried at 55° C. and crushed to obtain the fermented fresh corn flour.

[0088] The fermented fresh corn flour is added to fresh corn flour at a mass ratio of 50 parts of the fermented fresh corn flour to every 100 parts of fresh corn flour to obtain a product.

[0089] Example 3

[0090] A method for fermenting fresh corn and its application in product processing, the specific implementation plan is as follows:

[0091] S1: Harvesting and processing fresh corn cobs to obtain fresh corn cobs after harvest

[0092] The picking period of fresh corn cobs is 5 days later than the normal harvest period. After picking, the husks of the fresh corn cobs are peeled off and the surface is rinsed with water to remove impurities and debris such as residual husks and corn silk. After being spread out in a clean, dry and ventilated place for 15 hours, the 4 cm part of the tip of the fresh corn cobs is removed to obtain the fresh corn cobs after harvest.

[0093] S2: Processing of fresh corn cobs after harvest to obtain fresh corn crumbs

[0094] The harvested fresh corn cobs obtained in S1 were steamed with 100°C steam for 12 minutes, cooled to room temperature, and then threshed to obtain fresh corn kernels. The fresh corn kernels were placed in a wall-breaking machine and operated at a medium-low gear L4 for 10 seconds to obtain broken fresh corn kernels. The broken fresh corn kernels were placed in a 50°C oven and dried to a moisture content of 35% to obtain the fresh corn crumbs.

[0095] S3: Fresh corn crushed to prepare fresh corn culture medium

[0096] The fresh corn culture medium comprises fresh corn shreds, carrot shreds, terrestrial Issatchenia wet bacterial mud, riboflavin and nicotinamide.

[0097] Commercially purchased carrots were cleaned, washed, and cut into 2 cm chunks. The chunks were placed in a blender at setting L4 (medium-low) for 10 seconds to obtain shredded carrot chunks. The shredded carrot chunks were then dried in a clean, forced-air drying oven at 45°C until the moisture content reached 40%. This resulted in shredded carrots.

[0098] A loopful of Issatchenkia terricola WJL-G4 strains stored on a slant was inoculated into a liquid citric acid medium containing 20 g / L food-grade citric acid, 0.1 g / L food-grade MgSO₄, and 5 g / L food-grade yeast extract. Fermentation was performed at 28°C, 140 rpm, and a 12% (v / v) liquid-to-volume ratio for 18 h to obtain the I. terricola seed solution. A 5% (v / v) inoculum of the I. terricola seed solution was inoculated into a 20% (v / v) liquid citric acid medium. Fermentation was performed at 28°C and 140 rpm for 48 h, followed by centrifugation at 8000 rpm for 15 min to obtain the I. terricola wet slurry.

[0099] Separately, 69 mg of food-grade riboflavin and 40 mg of food-grade nicotinamide were weighed and added to 50 g of Issaffine wet slurry, and stirred thoroughly to mix evenly. The mixture was then added to 150 g of chopped carrots, and stirred thoroughly to mix evenly. 1500 g of the chopped fresh corn obtained in step S2 was then added, and stirred thoroughly to mix evenly. The mixture was packaged into 500 mL flasks, 150 g each, and sterilized at 115°C for 15 min. The mixture was then cooled to room temperature to obtain a fresh corn culture medium.

[0100] S4: Cultivate red Ganoderma lucidum strains and obtain fermented red Ganoderma lucidum seeds

[0101] Take a piece of the red Ganoderma lucidum slant culture stored in a 4°C refrigerator, transfer it to a Ganoderma lucidum solid plate culture medium, and culture it at a constant temperature of 25°C for 5 days to obtain the first-level red Ganoderma lucidum seeds. Cut a piece of the first-level red Ganoderma lucidum seeds, transfer it to a Ganoderma lucidum solid plate culture medium again, and culture it at a constant temperature of 25°C for 5 days to obtain the red Ganoderma lucidum fermented seeds.

[0102] The Ganoderma lucidum solid plate culture medium is composed of 12 g of Issaffine terrestrial wet culture slurry, 20 g of glucose, 150 g of potato, 0.25 g of MgSO4, and 20 g of agar per liter. The 150 g of potato should be boiled in water for 30 minutes and then filtered to obtain the filtrate. The Ganoderma lucidum solid plate culture medium is sterilized at 121°C for 15 minutes.

[0103] S5: Inoculate the fresh corn culture medium with Ganoderma lucidum fermentation seeds and ferment to obtain fermented fresh corn

[0104] The fermented red ganoderma seeds obtained in step S4 were inoculated into the fresh corn culture medium obtained in step S3 under sterile conditions, stirred evenly with a sterile glass rod, and then cultured in a 25° C. incubator for 8 days to obtain the fermented fresh corn.

[0105] The inoculation amount of the fermented red ganoderma seeds is 5 pieces of the fermented red ganoderma seeds with a size of 1.5 cm×2 cm in each bottle of the fresh corn culture medium, and after inoculation, the seeds are stirred evenly using a sterile glass rod.

[0106] S6: Dry and crush the fermented fresh corn to obtain fermented fresh corn flour for use in product processing

[0107] The fermented fresh corn obtained in step S5 is dried at 45° C. and crushed to obtain the fermented fresh corn flour.

[0108] The fermented fresh corn flour is added to rice flour at a mass ratio of 30 parts of the fermented fresh corn flour to every 100 parts of rice flour to obtain a product.

[0109] Example 4

[0110] Optimization of culture medium formulation for fresh corn.

[0111] This example uses red Ganoderma lucidum as the fermentation strain. A piece of red Ganoderma lucidum slant culture stored in a refrigerator at 4°C was transferred to a PDA solid plate culture medium. After constant temperature incubation at 22-28°C for 4 days, the culture medium was transferred to a PDA solid plate culture medium again and constant temperature incubation at 22-28°C for 4 days to obtain the red Ganoderma lucidum fermentation strain of this example.

[0112] Using only fresh corn crumbs as the control fermentation medium, and the triterpenoid content and mycelial biomass of Ganoderma lucidum as the judgment indicators, the effects of adding complex ingredients, external nitrogen sources, growth factors, etc. to fresh corn crumbs on the fermentation effect were screened.

[0113] (1) First, the relationship between mycelial biomass and ergosterol content was established.

[0114] A soybean-sized mycelium of Ganoderma lucidum was picked from the solid slant medium and transferred to the solid flat medium of Ganoderma lucidum. After culturing in a constant temperature incubator at 25 ℃ for 3-7 days, a piece was cut and transferred to the liquid medium of Ganoderma lucidum. The culture was carried out in a 250 mL triangular flask with 50 mL of liquid, 150 rpm, and constant temperature of 25 ℃ for 12 days. The fermentation was stopped on the 3rd, 5th, 7th, 9th, 11th, and 13th days of culture, and the mycelium biomass and ergosterol content in the triangular flask were determined. The results are shown in Table 1. Figure 1 As shown, a linear equation was established between Ganoderma lucidum mycelium biomass and ergosterol content.

[0115] The determination method of the Ganoderma lucidum mycelium obtained by liquid fermentation in this step is determined by weight method, and the determination method of ergosterol is determined by ultraviolet spectrophotometry.

[0116] The established linear equation is as follows:

[0117] y = 3.8963x + 0.588, R² = 0.9982

[0118] Where x represents the dry weight of Ganoderma mycelium biomass in g, and y represents the ergosterol content in mg.

[0119] Since it is difficult to separate mycelium in solid-state fermentation, this formula is used to calculate the biomass of Ganoderma mycelium in fermented fresh corn.

[0120] (2) Screening of compound ingredients

[0121] The culture medium contained only fresh corn shreds as a control fermentation medium. Fresh corn shreds were obtained according to the method of Example 3. 1000 g of fresh corn shreds was used as the basis, and 200 g of bran, soybean meal, pumpkin shreds, tomato shreds, carrot shreds, peanut shreds, sweet potato shreds, barley, wheat, sorghum rice, coix seed, and millet were added and sterilized to obtain the culture medium. Bran, soybean meal, barley, wheat, sorghum rice, coix seed, and millet were all added with water in advance to adjust the water content by mass to 40%; pumpkin shreds, tomato shreds, carrot shreds, peanut shreds, and sweet potato shreds were prepared according to the method for preparing carrot shreds in Example 3, and the water content by mass was adjusted to 40%; pumpkin was prepared with seeded pumpkin flesh. After adding the different composite ingredients, 150 g of culture medium was placed in each 500 mL triangular flask.

[0122] The culture conditions are as follows: 3 pieces of mycelium of 1.5 cm × 1.5 cm in size were cut from the fermented strain of red Ganoderma lucidum in this example under sterile conditions, inoculated into a conical flask, stirred evenly with a sterile glass rod, and then cultured in a 25°C incubator for 12 days. After the culture was completed, the ergosterol content in the fermentation product was measured to calculate the biomass of Ganoderma lucidum mycelium, the triterpene content was measured (i.e., the triterpene content of Ganoderma lucidum was determined by ultraviolet spectrophotometry), and the effects of various compound ingredients on the fermentation effect were compared. The results are as follows: Figure 2 shown.

[0123] Depend on Figure 2 As can be seen, adding 20% of various complex ingredients to fresh corn crumbs resulted in varying fermentation results. Samples containing coix seed, pumpkin, tomato, and sweet potato showed significant decreases in mycelial and triterpenoid content in Ganoderma lucidum after fermentation. Observation of the flasks revealed that the cultures containing coix seed, pumpkin, tomato, and sweet potato collapsed and Ganoderma lucidum growth was poor, suggesting that these three complex ingredients were detrimental to fermentation. Ganoderma lucidum growth was most significantly inhibited by the addition of peanuts. Cultures containing bran, soybean meal, carrot crumbs, barley, wheat, sorghum, and millet exhibited improved growth compared to the control, and mycelial biomass was higher in all three groups, indicating that the addition of these complex ingredients promoted Ganoderma lucidum growth. Triterpenoid content was significantly increased in the culture medium containing carrot crumbs, surpassing that of the other cultures. Therefore, the addition of carrot crumbs was the optimal fermentation complex based on both triterpenoid content and mycelial biomass.

[0124] (3) Screening of the amount of compound ingredients added

[0125] The triterpenoid content of Ganoderma lucidum and the biomass of Ganoderma lucidum mycelium were used as the judgment indicators. The culture medium containing only fresh corn shreds was used as the control fermentation medium. The weight percentages of carrot shreds added to the fresh corn shreds were screened to be 5%, 10%, 15%, 20%, and 25%, respectively. The inoculation and culture conditions in Example (2) were adopted. 150 g of culture medium was added to each 500 mL triangular flask. After the culture was completed, the ergosterol content was measured to calculate the biomass of Ganoderma lucidum mycelium, the triterpenoid content was measured, and the effects of various addition ratios on the fermentation effect were compared. The results are as follows. Figure 3 shown.

[0126] Depend on Figure 3 It can be seen that when the added mass percentages were 10%, 15%, 20% and 25% respectively, the growth of Ganoderma lucidum was better than that of other groups, and the mycelium biomass was higher. When the added mass percentages were 10%, 15% and 20% respectively, the triterpene content was significantly higher than that of other groups. Therefore, from the two aspects of triterpene content and mycelium biomass, the optimal addition amount was 10%-20% of shredded carrots.

[0127] (4) Screening of external nitrogen sources

[0128] A culture medium supplemented with fresh corn flakes and 15% chopped carrots by weight of the fresh corn flakes was used as a control fermentation medium. Fresh corn flakes and chopped carrots were obtained according to the method of Example 3. Based on 1000 g of fresh corn flakes in the culture medium, 20 g of yeast extract powder and peptone, 40 g of Saccharomyces cerevisiae wet slurry, and 40 g of Issaffron terrestrial WJL-G4 wet slurry were added, respectively, and the culture medium was sterilized.

[0129] The method for obtaining a wet slurry of Saccharomyces cerevisiae was as follows: a loopful of Saccharomyces cerevisiae strains stored on a slant was inoculated into YPD medium. Fermentation was performed at 28°C, 140 rpm, and a 12% (v / v) liquid-to-volume ratio for 12 h to obtain a Saccharomyces cerevisiae seed solution. The Saccharomyces cerevisiae seed solution was inoculated at an inoculum rate of 3% (v / v) into YPD medium with a 15% (v / v) liquid-to-volume ratio. Fermentation was performed at 28°C and 140 rpm for 48 h, followed by centrifugation at 8000 rpm for 15 min to obtain a wet slurry of Saccharomyces cerevisiae.

[0130] The wet slurry of Issatchenkia terricola WJL-G4 was obtained by selecting a loopful of Issatchenkia terricola WJL-G4 strains stored on a slant and inoculating it into a liquid citric acid medium containing 20 g / L food-grade citric acid, 0.1 g / L food-grade MgSO4, and 5 g / L food-grade yeast extract powder. The culture was fermented at 28°C, 140 rpm, and a 12% (v / v) liquid-to-volume ratio for 12 h to obtain the seed liquid of Issatchenkia terricola. The seed liquid of Issatchenkia terricola was then inoculated at an inoculum rate of 3% (v / v) into a liquid citric acid medium containing 15% (v / v) liquid-to-volume ratio. The culture was fermented at 28°C, 140 rpm, and centrifuged at 8000 rpm for 15 min to obtain the wet slurry of Issatchenkia terricola.

[0131] The culture medium with different external nitrogen sources was added, and the inoculation and culture conditions in Example (2) were adopted. 150 g of culture medium was placed in each 500 mL triangular flask. After the culture was completed, the triterpene content was determined and the biomass of Ganoderma mycelium was calculated. The effects of various external nitrogen sources on the fermentation effect were compared. The results are as follows: Figure 4 shown.

[0132] Depend on Figure 4 It can be seen that the group with 40g of terrestrial Issippica wet mud added had the highest triterpene content, which was significantly higher than that of other groups. Therefore, it was concluded that the addition of 40g of terrestrial Issippica wet mud significantly promoted the synthesis of triterpene substances.

[0133] (5) Screening of the amount of added nitrogen source

[0134] The triterpenoid content of Ganoderma lucidum and the biomass of Ganoderma lucidum mycelium were used as the judgment indicators. The culture medium was added with fresh corn crushed and carrot crushed accounting for 15% of the mass percentage of fresh corn crushed as the control fermentation medium. The fresh corn crushed and carrot crushed were obtained according to the method of Example 3. Based on 1000 g of fresh corn crushed in the culture medium, the addition amount of terrestrial Issaffron wet bacterial mud was screened to be 10, 20, 30, 40, 50, 60, 70, 80, and 90 g respectively. The inoculation and culture conditions in this Example (2) were adopted. 150 g of culture medium was added to each 500 mL triangular flask. After the culture was completed, the ergosterol content was measured to calculate the biomass of Ganoderma lucidum mycelium, the triterpenoid content was measured, and the effects of various addition ratios on the fermentation effect were compared. The results are as follows. Figure 5 shown.

[0135] Depend on Figure 5It can be seen that, based on 1000 g of fresh corn crumbs in the culture medium, adding 10-80 g of Issaffine wet slurry was beneficial to the synthesis of triterpenoids. When the addition amount was 20, 30, 40, 50, 60, and 70 g, respectively, Ganoderma lucidum grew well, and the triterpenoid content was higher than that of other groups. Therefore, the optimal addition amount was 20-70 g of Issaffine wet slurry when 1000 g of fresh corn crumbs was selected as the basis.

[0136] (6) Screening of growth factors

[0137] 1000 g of fresh corn flakes in the culture medium was used as the calculation basis, 150 g of carrot flakes and 40 g of terrestrial Issaffine wet mud were added, and 200 mg of thiamine, riboflavin, nicotinamide, pantothenic acid, biotin, pyridoxine, lipoic acid, and cyanocobalamin were added respectively, and the culture medium was obtained by sterilization. The inoculation and culture conditions in Example (2) were adopted, and 150 g of culture medium was added to each 500 mL triangular flask. After the culture was completed, the ergosterol content was measured to calculate the biomass of Ganoderma mycelium, the triterpene content was measured, and the effects of various growth factors on the fermentation effect were compared. The results are as follows. Figure 6 shown.

[0138] Depend on Figure 6 It can be seen that the addition of nicotinamide or riboflavin is beneficial to the increase of triterpenoid content, while the effect of other growth factors is not obvious. Therefore, further screening of the addition amount of nicotinamide and riboflavin was carried out.

[0139] (7) Screening of growth factor addition amount

[0140] 1000 g of fresh corn flakes in the culture medium was used as the calculation basis, 150 g of carrot flakes and 40 g of terrestrial Issaffron wet mud were added as the control group, and the treatment groups were respectively added with 20, 40, 60, 80, 100, 150, 200, and 250 mg of riboflavin, or 5, 20, 35, 50, 65, 80, 100, 150, 200, and 250 mg of nicotinamide, and the culture was divided into 150 g of culture medium per 500 mL triangular flask, and sterilized to obtain the culture medium; the inoculation and culture conditions in Example (2) were used, and after the culture was completed, the ergosterol content was measured to calculate the biomass of Ganoderma mycelium, the triterpene content was measured, and the effects of different growth factor addition amounts on the fermentation effect were compared. The results are as follows. Figure 7 shown.

[0141] Depend on Figure 7As can be seen from the middle left figure, when the riboflavin addition is 60 mg or more, the triterpene content is significantly increased compared with other additions, but when more riboflavin is added than 60 mg, there is no greater effect on the increase in triterpene content. Therefore, considering the triterpene content and cost, the optimal addition of riboflavin is 60-80 mg. Figure 7 As can be seen from the middle right figure, when the amount of niacinamide added is greater than or equal to 20 mg, the growth of Ganoderma lucidum and the triterpene content are both better. Considering the triterpene content and cost, the optimal amount of niacinamide added is 20-50 mg.

[0142] Example 5

[0143] Optimization of optimal fermentation culture conditions for fresh corn.

[0144] This example uses Ganoderma lucidum as the fermentation strain.

[0145] Based on 1000 g of fresh corn flakes in the culture medium, 150 g of carrot flakes and 70 g of Issaffine wet culture slurry were added, and then 60 mg of riboflavin and 35 mg of nicotinamide were added respectively to screen the effects of culture medium moisture content, culture temperature, culture medium filling amount, inoculation amount, and culture time on the fermentation effect.

[0146] (1) Screening of culture medium moisture content

[0147] Growth factors were screened by fermentation of Ganoderma lucidum (Ganoderma lucidum). 1000 g of fresh corn flakes in the culture medium was used as the calculation basis. 150 g of carrot flakes and 70 g of terrestrial Issaffron wet mud were added. 60 mg of riboflavin and 35 mg of nicotinamide were added respectively. The water content of the mixture of fresh corn flakes and carrot flakes in the culture medium was adjusted to 30%, 35%, 40%, 42.5%, 45%, 47.5%, 50% and 55% by mass. The culture medium was divided into 500 mL triangular flasks with 150 g of culture medium respectively. The culture medium was sterilized to obtain the culture medium. The inoculation and culture conditions in Example (2) were used. After the culture was completed, the ergosterol content was measured to calculate the biomass of Ganoderma lucidum mycelium, the triterpene content was measured, and the effects of different culture medium water contents on the fermentation effect were compared. The results are as follows. Figure 8 shown.

[0148] Depend on Figure 8 It can be seen that when the moisture content of fresh corn and carrot shreds is between 35% and 40%, the fermentation effect is better, and the mycelial biomass and triterpenoid content are higher than those in other moisture content groups. Therefore, it is determined that the moisture content of fresh corn and carrot shreds should be between 35% and 40%.

[0149] (2) Screening of culture temperature

[0150] Based on 1000 g of fresh corn shreds in the culture medium, 150 g of carrot shreds and 70 g of terrestrial Issaffron wet mud were added, and then 60 mg of riboflavin and 35 mg of nicotinamide were added respectively. The water content of the mixture of fresh corn shreds and carrot shreds in the culture medium was adjusted to 35% by mass. The culture medium was divided into 500 mL triangular flasks with 150 g of culture medium respectively, and sterilized to obtain the culture medium. The culture temperature was selected as 22, 25, 28, 31, and 34 °C. The other conditions were the inoculation and culture conditions in step (2) of Example 4. After the culture was completed, the ergosterol content was measured to calculate the biomass of Ganoderma mycelium, the triterpene content was measured, and the effects of different culture temperatures on the fermentation effect were compared. The results are as follows. Figure 9 shown.

[0151] Depend on Figure 9 It can be seen that when the culture temperature is 22-28 ℃, the growth of Ganoderma lucidum and the content of triterpenes are better, so 22-28 ℃ is selected as the optimal culture temperature.

[0152] (3) Screening of culture medium filling volume

[0153] Based on 1000 g of fresh corn flakes in the culture medium, 150 g of carrot flakes and 70 g of Issaffron terrestrial wet bacterial mud were added, and then 60 mg of riboflavin and 35 mg of nicotinamide were added respectively. The water content of the mixture of fresh corn flakes and carrot flakes in the culture medium was adjusted to 35% by mass. The culture medium was divided into 500 mL triangular flasks with 100, 150, 200, 250, and 300 g of culture medium respectively, and sterilized to obtain the culture medium. The other culture conditions adopted the inoculation and culture conditions in step (2) of Example 4. After the culture was completed, the ergosterol content was measured to calculate the biomass of Ganoderma lucidum mycelium, the triterpene content was measured, and the effects of different culture medium loading amounts on the fermentation effect were compared. The results are as follows. Figure 10 shown.

[0154] Depend on Figure 10As shown, when 100, 150, 200, and 250 ml of culture medium were loaded per 500 mL flask, triterpenoid and mycelial biomass were high by day 12 of growth, but growth rates varied between flasks. The smaller the loading volume, the faster the growth rate. With a 100 g loading volume, mycelium completely covered the medium and the flask by days 7-8 of fermentation; with 150 and 200 g loading volumes, mycelium completely covered the medium and the flask by days 9-10; and with 250 and 300 g loading volumes, mycelium completely covered the medium and the flask by days 11-13 of fermentation. However, with a loading volume of 300 g, stirring became difficult. Furthermore, the medium was too close to the flask mouth after stirring, which easily led to contamination and significantly prolonged fermentation time. Regarding triterpene content, a larger loading volume actually decreased triterpene content. Therefore, considering the triterpene content, fermentation efficiency and yield, it is appropriate to fill 100-250 g per 500 mL Erlenmeyer flask.

[0155] (4) Screening of inoculum size

[0156] Based on 1000 g of fresh corn shreds in the culture medium, 150 g of carrot shreds and 70 g of terrestrial Issaffron wet mud were added, and then 60 mg of riboflavin and 35 mg of nicotinamide were added respectively. The water content of the mixture of fresh corn shreds and carrot shreds in the culture medium was adjusted to 35% by mass. The culture medium was divided into 500 mL triangular flasks with 150 g of culture medium respectively, and sterilized to obtain the culture medium. The inoculation amount was selected from 1, 2, 3, 4, 5, and 6 pieces of 1.5 cm × 1.5 cm blocks. The other conditions adopted the inoculation and culture conditions in step (2) of Example 4. After the culture was completed, the ergosterol content was measured to calculate the biomass of Ganoderma mycelium, the triterpene content was measured, and the effects of different inoculation amounts on the fermentation effect were compared. The results are as follows. Figure 11 shown.

[0157] Depend on Figure 11 It can be seen that when the inoculation size is 3-6 blocks, the growth of triterpenes and mycelium is higher than that of other inoculation sizes; from the perspective of mycelium growth, the more blocks inoculated, the faster the mycelium grows. When 6 blocks are inoculated, the mycelium basically covers the surface of the culture medium on the 5th to 6th day of fermentation. When 1 block is inoculated, it takes 10-12 days for the mycelium to basically cover the surface of the culture medium. In order to improve the fermentation efficiency and achieve the fermentation effect as soon as possible, 3-6 blocks are selected as the optimal inoculation size.

[0158] (5) Screening of culture time

[0159] Based on 1000 g of fresh corn shreds in the culture medium, 150 g of carrot shreds and 70 g of terrestrial Issaffron wet mud were added, and then 60 mg of riboflavin and 35 mg of nicotinamide were added respectively. The water content of the mixture of fresh corn shreds and carrot shreds in the culture medium was adjusted to 35% by mass. The culture medium was divided into 500 mL triangular flasks with 150 g of culture medium respectively, and sterilized to obtain the culture medium. The culture time was selected as 4, 6, 8, 10, 12, 15, and 20 days. The other conditions were the inoculation and culture conditions in step (2) of Example 4. After the culture was completed, the ergosterol content was measured to calculate the biomass of Ganoderma mycelium, the triterpene content was measured, and the effects of different culture times on the fermentation effect were compared. The results are as follows. Figure 12 shown.

[0160] Depend on Figure 12 It can be seen that when the culture time is more than 6 days, the accumulation of triterpenoids is better. In order to achieve the best fermentation effect, the culture time can be extended to 12-15 days. According to the biomass of Ganoderma mycelium and triterpenoid content, combined with the time cost, 6-15 days is selected as the optimal culture time.

[0161] The method for obtaining fresh corn flakes, carrot flakes, and Issaffine terrestrial wet bacterial slurry in this example is the same as that in Example 3 unless otherwise specified. All materials or substances used are food grade.

[0162] Example 6

[0163] The fermented fresh corn obtained in Examples 1-3 was observed, active substances were determined, and fermented fresh corn flour was obtained.

[0164] Example 1-3 Fermentation and Fermentation of Fresh Corn Figure 13 As shown, Ganoderma lucidum grew well on the fresh corn culture medium, and the mycelium covered the entire triangular flask. The fermented fresh corn was dried according to the method described in Examples 1-3, and the triterpene content and Ganoderma lucidum mycelium biomass were measured. The results are as follows: Figure 14 shown.

[0165] Depend on Figure 14 It can be seen that the triterpene contents in the fermented fresh corn flour of Examples 1-3 after fermentation were 17.54±0.51, 19.22±0.92, and 19.59±0.50 mg / g, respectively, and the mycelium biomass was 64.46±3.24, 70.17±2.46, and 72.13±3.17 mg / g, respectively. The obtained fermented fresh corn flour contains rich triterpene active substances, which can be used in product production to effectively improve product quality.

[0166] The fermented fresh corn flour obtained by freeze-drying or drying at 55℃ and crushing is shown in Figure 15 As shown, Figure 15The left one is the fermented fresh corn flour that is dried and crushed at 55℃. Figure 15 On the right is freeze-dried and crushed fermented fresh corn flour. As can be seen from the picture, the fermented fresh corn flour is delicate and fluffy turmeric yellow, and has a strong aroma of large fungi.

[0167] The above descriptions are only some embodiments of the present invention and are not intended to limit the present invention. The scope of patent protection of the present invention shall be based on the claims. Any equivalent structural changes made using the contents of the description of the present invention shall also be included in the scope of protection of the present invention.

Claims

1. A method for fermenting fresh corn, characterized in that: The operation steps include: S1: harvesting and processing fresh corn cobs to obtain harvested fresh corn cobs; S2: processing the harvested fresh corn cobs to obtain fresh corn crumbs; S3: preparing a fresh corn culture medium with the fresh corn crumbs; S4: culturing Ganoderma lucidum strains to obtain Ganoderma lucidum fermentation seeds; S5: inoculating the Ganoderma lucidum fermentation seeds into the fresh corn culture medium to obtain fermented fresh corn; and S6: drying and crushing the fermented fresh corn to obtain fermented fresh corn flour. The fresh corn includes one or a mixture of sweet corn, glutinous corn, and sweet and glutinous corn; The Ganoderma lucidum is Ganoderma lucidum or Ganoderma sinense; The fresh corn culture medium comprises fresh corn shreds, carrot shreds, Issatchenia terrestris wet culture slurry, riboflavin, and nicotinamide. The specific preparation method is as follows: 60-80 mg of riboflavin and 30-50 mg of nicotinamide are weighed, added to 30-70 g of Issatchenia terrestris wet culture slurry, and stirred thoroughly; 150-200 g of carrot shreds are added thereto, and stirred thoroughly again to mix thoroughly; then, the mixture is added to 1000-1500 g of the fresh corn shreds, stirred thoroughly to mix thoroughly, and packaged into 500 mL triangular bottles, 100-250 g each, and sterilized at 115° C. for 15 minutes. The terrestrial Issatchenkia is terrestrial Issatchenkia (Issatchenkia terricola) WJL-G4, which was deposited at the General Microbiology Center of the China Culture Collection Administration on October 21, 2019, with a deposit number of CGMCC No. 18712. The proposed classification name is: Terrestrial Issatchenkia Issatchenkia terricola. The test result is that it is alive. The deposit address is: No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing.

2. The fermentation method of fresh corn according to claim 1, characterized in that: The step S1: harvesting and processing fresh corn cobs to obtain post-harvest fresh corn cobs comprises the following steps: picking the fresh corn cobs 3-7 days later than the normal harvesting period; peeling off the husks of the fresh corn cobs; rinsing the surface with water to remove impurities and debris including residual husks and corn silk; and airing the fresh corn cobs in a dry, ventilated, and clean place at room temperature for 10-15 hours. The tip of the fresh corn cobs, which is 3-5 cm in diameter, is then removed to obtain post-harvest fresh corn cobs.

3. The fermentation method of fresh corn according to claim 1, characterized in that: The S2: processing of harvested fresh corn cobs to obtain fresh corn crumbs, specifically comprises the following steps: steaming the harvested fresh corn cobs obtained in S1 with 100° C. steam for 10-15 minutes, taking them out, spreading them out in a clean and ventilated place to cool to room temperature, threshing them to obtain fresh corn kernels, placing the fresh corn kernels in a wall-breaking machine, operating the machine at a medium or low gear for 8-15 seconds to obtain broken fresh corn kernels, and drying the broken fresh corn kernels in a clean blast drying oven at 45-55° C. until the moisture content of the broken fresh corn kernels is 35-40%, thereby obtaining the fresh corn crumbs.

4. The fermentation method of fresh corn according to claim 1, characterized in that: The preparation method of the shredded carrots comprises the following steps: placing carrot pieces cut into 1-2 cm pieces in a wall-breaking machine, operating the machine at a medium-low gear for 10-20 seconds, and then drying the pieces in a clean blast drying oven at 45-55° C. until the moisture content reaches 35-40%, thereby obtaining the shredded carrots.

5. The fermentation method of fresh corn according to claim 1, characterized in that: In step S4, the composition of the Ganoderma lucidum solid plate culture medium used to obtain Ganoderma lucidum fermented seeds is 8-15g of Issatchenia terrestris wet bacterial mud, 15-25g of glucose, 150-200g of potato, 0.1-0.4g of MgSO4, and 20-25g of agar per liter.

6. The fermentation method of fresh corn according to claim 1, characterized in that: Inoculating the fermented Ganoderma lucidum seeds obtained in step S4 into the fresh corn culture medium obtained in step S3 under sterile conditions, stirring evenly with a sterile glass rod, and then culturing in an incubator at 22-28° C. for 6-12 days to obtain the fermented fresh corn; The inoculation amount of the Ganoderma lucidum fermentation seeds is 3-6 pieces of the Ganoderma lucidum fermentation seeds with a size of 1.5-2 cm×1.5-2 cm that are cut into each bottle of the fresh corn culture medium.

7. The fermentation method of fresh corn according to claim 1, characterized in that: The fermented fresh corn is dried and crushed to obtain the fermented fresh corn flour; the fermented fresh corn is freeze-dried or dried at 45-55° C. and crushed to obtain the fermented fresh corn flour.

8. Use of the fermentation method of fresh corn according to claim 7 in product processing.

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