Hazelnut meal fermented sauce and preparation process thereof

Abstract

The present invention relates to the field of food processing technology, and in particular to a hazelnut meal fermented paste and a preparation process thereof. The invention comprises the following steps: (1) drying; (2) screening; (3) steaming; (4) mixing and koji making: after the steamed hazelnut meal is cooled, it is inoculated with Aspergillus oryzae and cultured until spores multiply in the hazelnut meal in large quantities and appear as yellow-green blocks; (5) two-stage fermentation: after the hazelnut meal obtained in step (4) is added with salt water at a material-liquid ratio of 1:1-1.5, it is inoculated with halophilic Tetragenococcus (CGMCC NO.27586), fermented at 30-40°C, and after fermentation is completed, fermented at room temperature for 21-35 days; and (6) sterilization and pasteurization at a temperature of 80-90°C for 5-10 minutes. The invention improves the fermentation process to prepare hazelnut meal into fermented paste, fully utilizes hazelnut meal resources, utilizes the laboratory's independently intellectual property rights strain Tetragenococcus halophilus (CGMCC No. 27586) to achieve waste utilization, and prepares semi-solid and semi-liquid fermented paste, which significantly improves the umami taste of the fermented sauce and the rich hazelnut paste flavor.

Description

Technical Field

[0001] The invention relates to the field of food technology processing, in particular to a hazelnut meal fermented sauce and a preparation process thereof. Background Art

[0002] Hazelnut meal is a by-product of the hazelnut oil extraction process. It contains a large amount of nutrients such as protein and starch. Currently, hazelnut meal is mostly thrown away as waste or used as feed, which affects the environment and is not well utilized, resulting in waste.

[0003] Fermented foods are a special type of food formed during food processing with the participation of microorganisms or enzymes. They have a unique taste and local flavor. They can not only meet people's requirements for different flavors and tastes, but also have certain effects in terms of nutrition and physiological functions. Fermented sauce products are a type of fermented food. Their nutrients are more easily absorbed by the human body. Common fermented bean products, such as soybean paste products, can increase the originally low content of nutrients in soybeans, such as vitamins, amino acids and nucleotides, while still retaining the soybean's own biologically active substances such as isoflavones and oligosaccharides. At present, there is no research on the preparation of fermented sauce using hazelnut meal as raw material. If it can be prepared into fermented sauce through process research, it will have great application value and economic value. Summary of the Invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a hazelnut meal fermented paste and a preparation process thereof.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solutions:

[0006] The present invention provides a preparation process of hazelnut meal fermented paste, which comprises the following steps:

[0007] (1) Drying;

[0008] (2) sieving;

[0009] (3) Steamed;

[0010] (4) Mixed koji making: After the steamed hazelnut meal is cooled, it is inoculated with Aspergillus oryzae culture until the spores multiply in the hazelnut meal in large quantities and form yellow-green blocks;

[0011] (5) Two-stage fermentation:

[0012] The hazelnut meal obtained in step (4) is added with salt water at a material-liquid ratio of 1:1 to 1.5, inoculated with halophilic Tetragenococcus, fermented at 30°C-40°C, and fermented at room temperature for 21 to 35 days to obtain the product; the halophilic Tetragenococcus is Tetragenococcus halophilus SNTH-3, with a deposit number of CGMCC No. 27586 and a deposit date of June 8, 2023, deposited in the General Microbiology Center of the China Culture Collection Administration, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing; the preferred material-liquid ratio is 1:1, and the fermentation time is 28 days;

[0013] (6) Sterilization

[0014] Pasteurization, temperature 80-90℃, time 5-10 minutes.

[0015] In the above technical solution, further, the Aspergillus oryzae is Aspergillus oryzae Shanghai Niang 3.042 koji.

[0016] In the above technical solution, further, in the step (4), the culture temperature is 30-35° C., the culture is 36-48 hours, and the koji is turned every 4-6 hours during the culture.

[0017] In the above technical solution, further, in step (5), the concentration of the brine is 12%-16%, and the fermentation time is 28 days.

[0018] In the above technical solution, further, the added amount of Aspergillus oryzae and Tetragenococcus halophilus is 4% to 6% of the mass of the hazelnut meal raw material, wherein the mass ratio of Aspergillus oryzae to Tetragenococcus halophilus is 4:2-2:4.

[0019] In the above technical solution, further, the mass ratio of Aspergillus oryzae to Tetragenococcus halophilus is 1:1.

[0020] In the above technical solution, further, the drying temperature is 50° C. and the drying time is 30 minutes.

[0021] In the above technical solution, further, the screening is a 100-mesh sieve.

[0022] In the above technical solution, further, the hazelnut meal is mixed with water in a ratio of 1:1 and then steamed at 100°C under normal pressure.

[0023] The present invention also provides a hazelnut meal fermented sauce, which is prepared by the above process.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The invention makes the hazelnut meal into fermented paste, thereby fully utilizing the hazelnut meal resources, realizing waste utilization and avoiding resource waste.

[0026] The invention prepares semi-solid and semi-liquid fermented sauce through an improved fermentation process, which has a strong hazelnut paste aroma, prolongs the storage period and significantly improves the bioactive components.

[0027] The invention selects Aspergillus oryzae and halophilic tetragenococcus for two-stage fermentation. Based on the fact that hazelnut meal contains a large amount of protein, starch, cellulose and the like, Aspergillus oryzae can produce protease in the first-stage fermentation to hydrolyze the protein into free amino acids. The produced amylase and cellulase can hydrolyze starch and cellulose to obtain glucose and maltose. In addition, solid-state fermentation is used in the Aspergillus oryzae fermentation stage, which greatly reduces the fermentation time. The second-stage fermentation is carried out by halophilic tetragenococcus, which makes the fermentation more thorough. The halophilic tetragenococcus can grow in a high osmotic pressure environment and can combine with protease to hydrolyze protein, making the protein hydrolysis more thorough, thereby increasing the content of polypeptides and amino acids. At the same time, the extracellular polysaccharides, polyphenols and flavonoids produced by the halophilic tetragenococcus can improve the antioxidant activity. The two-stage fermentation process is used to prepare hazelnut meal fermented sauce, which can solve the problem of single fermentation flavor, significantly improve the active substances of the fermented sauce, increase the umami taste, reduce the bitterness and astringency, and improve the flavor and mouthfeel after fermentation.

[0028] The halophilic Tetragenococcus (CGMCC NO.27586) used in the present invention is a superior strain screened by our laboratory and has obvious functions of enhancing flavor and aroma, which significantly improves the flavor and rich sauce aroma of the fermented sauce. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a sensory comparison chart of the electronic tongue after fermentation.

[0030] Figure 2 The results of the effect of different strain mass ratios on hazelnut meal fermentation paste.

[0031] Figure 3 Total ion current of the non-fermented group.

[0032] Figure 4 Total ion current diagram of Aspergillus oryzae fermentation group.

[0033] Figure 5 Total ion chromatogram of the two-stage fermentation of Aspergillus oryzae and Tetragenococcus halophilus. DETAILED DESCRIPTION

[0034] The present invention will be further described below with reference to specific examples, but the present invention is not limited thereto in any way.

[0035] The hazelnut meal used in this application is the waste hazelnut meal after cold-pressing hazelnut oil. Spore powder of Aspergillus oryzae Shanghai Niang 3.042 was purchased from Jining Xiangyuan Biotechnology Co., Ltd. The halophilic Tetragenococcus SNTH-3 strain is deposited under the CGMCC No. 27586.

[0036] Example 1

[0037] Step 1: Raw material pretreatment

[0038] (1) Hazelnut meal drying: The hazelnut meal was placed in a drying oven and dried at 50°C for 30 minutes to remove excess moisture.

[0039] (2) Screening of hazelnut meal: Put the dried hazelnut meal into a multifunctional grinder and grind it. After grinding, sieve it through a 100-mesh sieve and take the material under the sieve.

[0040] (3) Preparation of MRS liquid medium: peptone 1%, yeast extract 0.5%, diammonium hydrogen citrate 0.2%, glucose 2%, sodium acetate 0.3%, dipotassium hydrogen phosphate 0.2%, magnesium sulfate 0.058%, manganese sulfate 0.025%, beef extract 1%, Tween-80 0.1%.

[0041] (4) Halophilic Tetragenococcus (CGMCC NO. 27586) stored at -80°C was inoculated into MRS liquid culture medium, activated at 37°C and 180 rpm for 24 h, and passaged twice before use.

[0042] Step 2: Steam the ingredients

[0043] Put the crushed and sieved hazelnut meal on an induction cooker and steam it at normal pressure at 100°C for 30 minutes until the raw material is cooked and fragrant.

[0044] Step 3: Mixing Aspergillus oryzae to make koji

[0045] Cool the steamed hazelnut meal to about 30°C and inoculate with koji essence. Place the steamed hazelnut meal and Aspergillus oryzae 3.042 fungus powder in a beaker and mix thoroughly. Remove and place in a constant temperature electric incubator set to 35°C. Turn the koji every 4-6 hours and incubate for 48 hours. Wait until the spores multiply in the hazelnut meal and turn yellow-green. The appearance is blocky, the interior is loose and soft, and the mycelium is abundant. The spores will fly when touched by fingers. The koji has a special strong koji aroma without sourness, koji odor or other odors.

[0046] Step 4: Two-stage fermentation

[0047] Pour the prepared hazelnut meal into a fermentation tank, flatten and compact it. Add 14% 40°C hot salt water at a 1:1 ratio of material to liquid to the surface, allowing it to gradually penetrate the koji and stir evenly. Inoculate the cultured halophilic Tetragenococcus, stir evenly, and ferment at 30-32°C. Maintain this temperature until the mash matures. Stir and stir thoroughly once daily to expel air. Once fermentation is complete, post-ferment at room temperature for 28 days to obtain the finished product.

[0048] The addition amount of halophilic Tetragenococcus (CGMCC NO.27586) and Aspergillus oryzae 3.042 is 6% of the mass of the hazelnut meal raw material, wherein the mass ratio of halophilic Tetragenococcus to Aspergillus oryzae 3.042 is 1:1.

[0049] Step 5: Sauce making and sterilization

[0050] The sealed, fermented sauce will be pasteurized to preserve its nutritional value and flavor. Sterilization conditions: 80-90°C for 5-10 minutes.

[0051] The reducing sugar content of the fermented hazelnut meal paste was determined to be 51.36±0.37 mg / g; the nitrite content was 3.71±0.08 mg / Kg <10 mg / Kg, which was in line with national standards; according to the agricultural industry standard of the People's Republic of China "Fermented soybean meal as feed raw material" and the national mandatory standard GB2712-2003 "Hygiene Standard for Fermented Soybean Products", the hygiene indicators of fermented soybean meal products should meet the requirement of coliform group <0.3 MPN / g, and the coliform group count was 0.15 MPN / 100g <0.3 MPN / g, which was in line with national standards; no pathogenic bacteria (Salmonella, Shigella, Staphylococcus aureus) were detected, which was in line with national health standards.

[0052] Example 2

[0053] The indicators of the hazelnut meal fermented sauce prepared above were compared with those of the fermented sauce obtained by fermenting only with Aspergillus oryzae, as shown in Table 1:

[0054] Table 1

[0055] Item / Component Aspergillus oryzae fermentation Two-step fermentation of Aspergillus oryzae and Tetragenococcus halophilus Reducing sugar (mg / g) 44.13±0.44 51.36±0.37 Amino acid nitrogen (g / 100g) 0.46±0.12 0.83±0.19 Total acid (g / Kg) 0.51±0.14 0.92±0.34 Total phenols (mgGAE / 100g) 44.61±0.45 56.71±0.35 Total flavonoids (mg / 100g) 121.33±0.61 164.21±0.39

[0056] As can be seen from the data in the table above, the present invention adopts the two-step fermentation method of Aspergillus oryzae and Tetragenococcus halophilus, and its reducing sugar content, amino acid nitrogen content, total acid content, total phenol content, and total flavonoid content are all higher than those of fermentation with Aspergillus oryzae alone, and the nutritional content is improved. The sensory comparison of the hazelnut meal fermentation sauce prepared above and the fermentation sauce obtained by fermentation with Aspergillus oryzae alone was performed using an electronic tongue, and it was seen that Figure 1 .Depend on Figure 1The results show that the fermented hazelnut meal sauce of the present invention has increased sourness and umami, and significantly reduced bitterness and astringency compared to the fermented sauce obtained by fermenting with Aspergillus oryzae alone.

[0057] Example 3

[0058] Fermented hazelnut meal paste was prepared using the method of Example 1, except that the mass ratios of Tetragenococcus halophilus to Aspergillus oryzae 3.042 were 5:1, 4:2, 1:1, 2:4, and 1:5, respectively. Sensory scores and amino acid nitrogen content were evaluated at different mass ratios.

[0059] Sensory Evaluation Method: The sensory evaluation of hazelnut meal fermented paste was conducted with reference to the sensory requirements of GB / T 24399-2009, "Soybean Paste." A sensory evaluation panel of 10 experts with professional sensory training was conducted in a standard sensory laboratory. The color, flavor, odor, and textural morphology of the hazelnut meal fermented paste samples were scored according to Table 2, with color accounting for 20 points, odor for 30 points, flavor for 40 points, and textural morphology for 10 points, for a total of 100 points.

[0060] Table 2 Sensory evaluation standards

[0061]

[0062] The fermentation results of different strain mass ratios are shown in Figure 2 ,Depend on Figure 2 As can be seen, the amino acid nitrogen content showed a gradual increase followed by a decrease with the change in the strain mass ratio. At a strain mass ratio of 1:1, the sensory score reached a maximum of 95.36±0.49, and the amino acid nitrogen content increased significantly. However, the amino acid nitrogen content and sensory score of the subsequent groups decreased. This may be due to the fact that the enzyme system produced by Aspergillus oryzae has a greater effect on protein during fermentation, and the relative increase in the halophilic Tetragenococcus can enhance protein hydrolysis, leading to an increase in amino acid nitrogen content. The amino acid nitrogen content and sensory score of the groups with a relatively increased halophilic Tetragenococcus content, such as the 2:4 and 1:5 ratios, decreased. This may be due to the increased lactic acid bacteria content, which produced excessive lactic acid and organic acids, hindering Aspergillus oryzae from producing proteases that can hydrolyze proteins, resulting in an overly sour taste and a decreased sensory score.

[0063] Example 4

[0064] The volatile flavor compounds of hazelnut meal before and after fermentation were detected by HS-SPME-GC / MS technology. Figure 3 、 Figure 4 、 Figure 5The total ion current diagrams of three groups of samples are shown. TSF is a two-stage fermentation group with Aspergillus oryzae and Tetragenococcus halophilus, i.e., the hazelnut meal fermented sauce prepared in Example 1. The control group UF is an unfermented sample, i.e., a 1:1 mixture of hazelnut meal and distilled water, fermented without adding bacteria. The control group ASF is a single-bacterium Aspergillus oryzae fermentation group, i.e., fermented with only Aspergillus oryzae without adding Tetragenococcus halophilus.

[0065] Experimental method: Sample treatment method: weigh 2.0g of sample into the headspace bottle, add 2.0g of NaCl solution to adjust the ionic strength, and then add 2uL of 0.816×10 -4 100 μg / mL dimethyltriheptanone was used as the internal standard. Volatile flavor compounds were enriched and extracted using a 50 / 30 μm PDMS / DVB extraction tip. The extraction temperature was 50°C, the equilibration time was 10 minutes, and the extraction time was 40 minutes. After extraction, the sample was desorbed at 250°C for 5 minutes before GC-MS analysis.

[0066] Gas chromatography (GC) conditions: a DB-WAX capillary column (30 m × 0.25 mm × 0.25 μm), a column flow rate of 1.8 mL / min, and helium as the carrier gas. The oven temperature program was as follows: hold at 40°C for 3 min, increase to 100°C at a rate of 5°C / min, hold for 0 min, and then increase to 220°C at a rate of 6°C / min and hold for 10 min.

[0067] Mass spectrometry (MS) conditions: electron impact EI ion source mode; electron energy 70 Ev; transfer line temperature 250°C; ion source temperature 230°C; quadrupole temperature 150°C; mass scan range 40-350 AMU; solvent delay 0 min.

[0068] Qualitative and quantitative analysis of volatile substances: The detected compounds (those with a matching degree greater than 80 are considered as credible data) were qualitatively analyzed by mass spectrometry by searching the CAS number database, and quantitatively analyzed by the internal standard method. The internal standard was dimethyltriheptanone, and the quantitative analysis was performed using the quantitative formula (1):

[0069]

[0070] Where: A1 is the peak area of ​​each volatile aroma compound, A2 is the peak area of ​​the internal standard, C is the concentration of the internal standard in μg / mL, V is the volume of the internal standard in mL, and m is the sample weight in g.

[0071] Experimental results: as shown in Table 3

[0072] Table 3 Determination of volatile flavor substances in three groups of samples

[0073]

[0074]

[0075]

[0076]

[0077] Hazelnut meal is primarily a byproduct of defatting and degreasing hazelnuts, resulting in an extremely low fat content. Its primary nutrients include proteins, amino acids, polysaccharides, and carbohydrates. These substances generate new volatile flavor compounds through novel pathways. Previous research has shown that these pathways primarily involve the Maillard reaction, lipid oxidation, and thermal degradation of precursors such as free amino acids, carbohydrates, and nucleic acids. Fermentation can significantly improve the nutritional value, flavor, and utilization of raw materials, extending product processing possibilities and broadening product categories. Flavor compounds are a key characteristic of fermented sauces. During the fermentation process, the bacteria and the enzymes they produce degrade various nutrients through a series of metabolic activities, thereby increasing the content of certain aroma compounds or generating new ones.

[0078] As shown in the table, different fermentation methods resulted in varying degrees of changes in the volatile compounds in hazelnut meal. The two-stage fermentation (TSF) group showed significantly higher volatile compound types and contents than the Aspergillus oryzae fermentation group (ASF) and the control group (UF). This suggests that different fermentation methods altered the aroma types and characteristics of the original samples, increasing the diversity of aroma compounds. Alcohols are primarily produced through sugar metabolism, amino acid decarboxylation, and dehydrogenation, and are metabolites of lactic acid bacteria and other microorganisms during the fermentation process. n-Pentanol, phenylethanol, isopentanol, and 2-pentanol were detected in all three groups. Isobutanol, 2,3-butanediol, 2-methylpropanol, 3-methylthiopropanol, and furfuryl alcohol were newly detected in two fermentation groups. The production of these alcohols is primarily due to bacterial metabolism, resulting in glycolysis and the generation of new alcohols. 3-Methylthiopropanol and furfuryl alcohol, among them, have a soy sauce flavor, boiled potato flavor, and a burnt aroma, and are characteristic aroma compounds of fermented sauce products.

[0079] Aldehydes are mainly produced by the metabolism of amino acids and fatty acids. The aldehyde content of the two fermentation groups was 1.12 times and 1.46 times that of the control group, respectively. This indicates that the protease produced by the bacteria hydrolyzes proteins to form amino acids, which are further hydrolyzed into aldehydes, thereby obtaining new aldehyde compounds and increasing the content of aldehydes. Among them, 3,4-dimethylbenzaldehyde, 3,5-dimethylbenzaldehyde, 2-phenylcrotonaldehyde, vanillin, 3-methylthiopropionaldehyde, furfural, and veratraldehyde were only detected in the two-stage fermentation group. They showed almond, moldy, lavender, onion, caramel, and woody aromas, respectively. Not only that, the 2-methylbutanal, 3,5-dimethylbenzaldehyde, and benzaldehyde in the three groups of samples showed almond, coffee, and nutty flavors, respectively. The content of these substances increased in turn, giving the hazelnut meal fermented paste a unique nutty flavor.

[0080] Ketones usually have pleasant aromas such as floral and fruity scents. The ketone substances produced and their contents in the two fermentation groups were significantly higher than those in the control group. Among them, the contents of 4-heptanone, 2-heptanone, and 2-nonanone were significantly higher than those in the control group. The aroma characteristics of these compounds were reflected in cheese aroma, medicinal aroma, and coconut aroma. Secondly, the newly produced ketone substances in the fermentation group included 3-methyl-4-heptanone, 3-hydroxy-4-heptanone, 3-hydroxy-2-butanone, isoheptanone, and o-aminoacetophenone, while 2-pentanone was only detected in the two-stage fermentation group, mainly showing floral and fruity aromas. Among them, 3-methyl-4-heptanone had a nutty flavor, which provided the hazelnut meal fermented paste with a unique nutty flavor.

[0081] Esters in hazelnut meal fermented paste typically come from two sources: 1. The esters are produced by the halophilic Tetragenococcus during fermentation, which reacts with alcohols to form esters; 2. They are also produced by the microbial degradation of amino acids during the fermentation process. Esters impart a unique ester flavor to fermented foods and are a key characteristic of hazelnut meal fermented paste. Five, 10, and 15 ester types were detected in the three sample groups, respectively. The fermentation group had significantly higher ester content than the control group, with the two-stage fermentation group showing the highest ester variety and content, reaching 76.98 μg / kg. Ethyl phenylacetate, methyl lactate, and ethyl lactate were only detected in the two-stage fermentation group, all of which possess a sweet, fruity aroma.

[0082] Volatile acids are important precursors of compounds such as ketones, aldehydes and esters. Acids are mainly derived from the degradation of fats and amino acids or microbial metabolism. Hexanoic acid, isobutyric acid and benzoic acid were detected in the fermentation group, showing sour smell, fermentation-like sour smell and floral aroma respectively. Acids usually provide a disgusting rancid taste, but because the thresholds of these acid substances are very high, there is not much difference in the contribution of acid substances to the flavor of hazelnut meal fermentation sauce. In fermented foods, acids are generally produced by bacteria.

[0083] Phenolic compounds contribute to the aroma characteristics of hazelnut meal fermented paste, including smoky and spicy notes. Only one phenolic compound, phenol, was detected in the control group, and phenol content increased significantly in both fermentation groups, resulting in a burnt aroma. The Aspergillus oryzae fermentation group produced five new phenolic compounds compared to the control group: guaiacol, m-cresol, eugenol, 4-vinylguaiacol, and 2,6-dimethoxyphenol. These compounds exhibit smoky and medicinal aromas, musty odors, clove-like aromas, phenolic odors, and woody aromas, respectively. The two-stage fermentation group produced 4-methylphenol and 3,4-dimethoxyphenol, with 4-methylphenol exhibiting a phenolic odor. Phenol, 2,6-dimethoxyphenol, and 4-vinylguaiacol are the most important phenolic compounds in Pixian doubanjiang, contributing medicinal, spicy, and smoky aromas, respectively. 2,6-dimethoxyphenol was identified for the first time. Guaiacol and 4-methylguaiacol are the most important phenolic compounds in Pixian Doubanjiang (fermented bean paste), contributing to its smoky and vanilla aromas. Phenol and guaiacol are also important aroma components of domestic fermented soybean paste. Guaiacol, 4-vinylguaiacol, and 4-ethylphenol contribute significantly to the aroma of Japanese miso and Korean doenjang (soybean paste). Phenol and guaiacol are primarily produced by certain bacteria through the degradation of amino acids.

[0084] Heterocyclic compounds are primarily formed during the heating and cooking processes of certain foods, through pathways that also involve the Maillard reaction, lipid redox reactions, and carbohydrate thermal reduction degradation and rearrangement reactions. Initially, samples in the pre-treatment groups were steamed before inoculation and fermentation. 2,3,5-Trimethylfuran, 2-pentylfuran, and 2,5-dimethylpyrazine, detected in all three groups, exhibit bean and nutty aromas, respectively, contributing to the unique nutty flavor of hazelnut meal fermented paste. 2-Acetylfuran and 2,3,5,6-tetramethylpyrazine, detected in both fermentation groups, contribute to the burnt and soy aromas of hazelnut meal fermented paste, respectively. Studies have shown that 2,3,5,6-tetramethylpyrazine, first detected in broad bean paste, is formed through the dehydrogenation of amino acids by amino acid dehydrogenase to form ammonia, which then condenses with 3-hydroxy-2-butanone to form tetramethylpyrazine. 3-Hydroxy-2-butanone is the primary upstream building block of 2,3,5,6-tetramethylpyrazine. 3-Hydroxybutanone is primarily obtained via the diacetyl pathway, a precursor for the synthesis of 3-Hydroxybutanone and 2,3-butanediol. However, in this study, the precursors 3-Hydroxy-2-butanone and 2,3-butanediol were only detected in two fermentation groups, consistent with the results of this study.

[0085] From the overall results, compared with the Aspergillus oryzae single-bacteria fermentation group, the two-stage fermentation of Aspergillus oryzae and halophilic Tetragenococcus increased the content and types of flavor substances in hazelnut meal fermentation sauce, increased the diversity of volatile flavor substances, and solved the problem of single flavor of single-bacteria fermentation.

[0086] Anyone skilled in the art will be able to utilize the above-disclosed technical content to make many possible changes and modifications to the technical solution of the present invention, or to modify it into equivalent embodiments with equivalent changes, without departing from the scope of the technical solution of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention that do not depart from the content of the technical solution of the present invention shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A preparation process for hazelnut meal fermented paste, characterized in that: The process comprises the following steps: (1) Drying of hazelnut meal; (2) sieving; (3) Steam until cooked; (4) Mixed koji making: After the steamed hazelnut meal is cooled, it is inoculated with Aspergillus oryzae and cultured until the spores multiply in the hazelnut meal in large quantities and form yellow-green blocks; (5) Two-stage fermentation: The hazelnut meal obtained in step (4) is added with salt water at a material-liquid ratio of 1:1-1.5, and then inoculated with halophilic Tetragenococcus, fermented at 30°C-40°C, and fermented at room temperature for 21-35 days to obtain the hazelnut meal; the halophilic Tetragenococcus is Tetragenococcus halophilus SNTH-3, with a preservation number of CGMCC No. 27586; (6) Sterilization: Pasteurization, temperature 80-90℃, time 5-10min; The addition amount of Aspergillus oryzae and Tetragenococcus halophilus is 4% to 6% of the mass of the hazelnut meal raw material, wherein the mass ratio of Aspergillus oryzae to Tetragenococcus halophilus is 4:2-2:4, and the Aspergillus oryzae is Aspergillus oryzae Shanghai Niang 3.042 koji.

2. The preparation process of hazelnut meal fermented paste according to claim 1, wherein In the step (4), the culture temperature is 30-35°C, the culture is carried out for 36-48 hours, and the koji is turned over every 4-6 hours during the culture.

3. The preparation process of hazelnut meal fermented paste according to claim 1, characterized in that: In the step (5), the concentration of the brine is 12%-16%.

4. The preparation process of hazelnut meal fermented paste according to claim 1, characterized in that: The mass ratio of Aspergillus oryzae to Tetragenococcus halophilus is 1:

1.

5. The preparation process of hazelnut meal fermented paste according to claim 1, characterized in that: In step (1), the drying temperature is 50°C and the drying time is 30 min.

6. The preparation process of hazelnut meal fermented paste according to claim 1, characterized in that: The sieving is a 100 mesh sieve.

7. A fermented hazelnut meal sauce, characterized in that: Prepared by any process of claims 1 to 6.

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