Preparation method of chestnut distilled liquor with fruity flavor

Abstract

The invention discloses a preparation method of a chestnut distilled liquor with fruity flavor, belonging to the field of chestnut distilled liquor brewing. The invention uses 100% chestnuts as raw materials, and through the Maillard reaction during baking, ketone and aldehyde flavor substances are generated. At the same time, a four-enzyme preparation three-stage saccharification process is adopted, generating abundant fermentable sugars and amino acids, providing substrates for yeast metabolism, and the content of flavor substances generated by fermentation metabolism is relatively high. No flavoring and flavor substances are added in the production process. The produced chestnut distilled liquor contains ethyl octanoate with brandy aroma, ethyl lactate with floral, fruity and sweet aroma, ethyl acetate which is the main flavor substance of light-flavor liquor with banana or apple aroma. At the same time, the furfural content is relatively high, and the liquor body also contains a faint soy sauce aroma. The complex flavor substances effectively enrich the flavor of the chestnut distilled liquor, making up for the defect of insufficient aroma of distilled liquor made from a single raw material, having the unique elegant and harmonious fruity and floral aroma of chestnuts and a strong liquor aroma, and at the same time also containing a faint soy sauce aroma.

Description

Technical Field

[0001] The invention relates to the technical field of chestnut distilled liquor brewing, and in particular to a method for preparing fruity flavor chestnut distilled liquor. Background Art

[0002] Chestnuts are rich in nutrition. In addition to being rich in starch, protein, and fat, they also contain a variety of vitamins and mineral elements such as Ca, Fe, P, K, Mg, and Zn. Starch accounts for 45%-65% of its dry matter, and protein accounts for 7%-20%. The kernel protein contains 18 kinds of amino acids, including 8 essential amino acids. These nutrients form the quality and style of chestnuts, which are delicate, sweet, and delicious, and have a unique flavor. They play an important role in promoting human physiological functions and improving human health. They have the functions of nourishing the kidneys, strengthening the spleen, preventing cancer, and curing cancer. They have a significant conditioning effect, especially for the elderly and patients with hypertension, coronary heart disease, and arteriosclerosis.

[0003] Chestnut is a seasonal food. Due to the single consumption mode and poor storage resistance, more than 30% of chestnuts rot and deteriorate every year, which has caused serious waste of my country's high-quality chestnut resources. At present, the main products processed from chestnuts are chestnut kernels, quick-frozen chestnut kernels, chestnut cakes and chestnut paste. There are no reports in China on using chestnuts as the main raw material to produce distilled liquor. Some researchers have tried to use chestnuts to brew fruit wine or use chestnuts as auxiliary materials to brew liquor, but they have not been able to form a scale due to the lack of consumer groups and low raw material utilization.

[0004] Due to the high starch content of chestnuts, the lack of saccharifying enzymes to convert starch into fermentable sugars that can be used by yeast, and the protein content of more than 7%, the traditional winemaking method uses chestnuts as auxiliary materials and adopts solid-state fermentation method, using enzyme preparations produced by koji microorganisms to decompose chestnut starch and protein, so as to ferment and produce alcohol. The traditional method has problems such as low enzyme activity, poor enzyme preparation specificity, and long fermentation time. The starch and protein conversion rate is low, resulting in low utilization of chestnut resources. Summary of the invention

[0005] In view of the above shortcomings, the present invention provides a method for preparing fruity flavored chestnut distilled liquor. Compared with traditional winemaking methods, the present invention adopts 100% chestnuts as raw materials based on the characteristics of chestnuts, creatively utilizes a three-stage saccharification method with four enzyme preparations, adds protein decomposition and saccharification stages, can convert 100% of chestnut starch and convert large molecular proteins into amino acids that can be used by yeast, adopts liquid fermentation to achieve efficient utilization of chestnut starch, and at the same time, yeast metabolism produces rich flavor substances.

[0006] The technical solution adopted by the present invention to solve the technical problem is: a method for preparing fruity flavored chestnut distilled liquor, wherein the chestnut juice is saccharified by a three-stage saccharification method:

[0007] ① Crushing and slurrying: Crush chestnut kernels with a crusher, add water to make a slurry according to a ratio of 1:2.5, and adjust the pH value of the slurry to 5.2 - 5.4;

[0008] ② First saccharification: Add α - amylase, raise the temperature to 90 °C, keep warm for 30 min for gelatinization and liquefaction. Stir continuously during this period, test the reaction of iodine with starch, and when no blue color appears, all starch is converted;

[0009] ③ Second saccharification: Lower the temperature to 52 °C, add protease, and keep warm for 30 min;

[0010] ④ Third saccharification: Raise the temperature to 63 °C, add β - amylase and glucoamylase, and keep warm for 60 min;

[0011] ⑤ Extract concentration adjustment: Add sterile water to adjust the extract concentration to 14 - 16 °P.

[0012] After saccharification, the subsequent steps of the preparation method are: fermentation, distillation, aging, and bottling.

[0013] The specific steps of the fermentation are as follows:

[0014] ① Yeast addition: When the temperature of the chestnut saccharified juice obtained after saccharification is cooled to 20 °C, put it into a tank, add yeast, and the addition amount is 200 g / t saccharified juice, and then put it into a stainless - steel barrel for fermentation;

[0015] ② Fermentation monitoring: Measure the temperature and sugar content of the fermentation broth every 6 hours, and control the fermentation temperature at 18 - 20 °C;

[0016] ③ Fermentation termination: When the sugar content of the fermentation broth has not changed for 24 consecutive hours, terminate the fermentation to obtain base wine.

[0017] The steps of the distillation are as follows:

[0018] Use the double - distillation method. Distill the chestnut fermented wine, recover the distillate, and monitor the ethanol content. When the ethanol content < 3%, stop distillation, combine to obtain the rough - distilled original wine, and repeat the distillation of the rough - distilled original wine. Cut off the heads and tails during the distillation process and take the middle fraction.

[0019] The steps of the aging are as follows:

[0020] The distilled original wine is aged in a glass container or a stainless - steel container for at least 24 months.

[0021] The steps of the bottling are as follows:

[0022] ① Filtration: Filter the original wine with good stability using a membrane filtration filter;

[0023] ② The filtered original wine is bottled, labeled, and packaged.

[0024] The steps before saccharification in the preparation method are as follows: Baking and shelling:

[0025] ① Screening: Select fresh chestnuts that are mature, free from mildew and dust.

[0026] ② Baking and shelling: Bake at 180°C for 40 minutes, then remove the shell and skin to obtain chestnut kernels.

[0027] The preparation method of the chestnut distilled liquor provided by the present invention adopts special baking and saccharification processes, ferments using yeast, and obtains a chestnut distilled liquor with a sweet floral and fruity aroma, a sweet and mellow taste in the mouth, and no irritation. Due to the use of exogenous enzyme preparations, the efficient conversion of starch and protein is achieved. The liquid fermentation process is adopted during fermentation, which has the characteristics of high chestnut utilization rate and fast fermentation speed. 1 kg of chestnut distilled liquor can be produced from every 2 - 3 kg of chestnuts. At the same time, the fermentable sugars and α - amino nitrogen content in the saccharified juice produced by saccharification are rich, providing a carbon source and a nitrogen source for yeast growth, providing a good metabolic substrate for yeast growth. Yeast grows strongly during the fermentation process, and rich flavor substances are produced by metabolism. The chestnut distilled liquor produced with whole chestnuts as raw materials not only contains the fruity aroma of chestnuts itself, has a mellow, sweet, clean, and non - irritating taste, and a harmonious liquor body, but also adopts single - strain pure fermentation, and the produced distilled liquor has a clean aroma, no peculiar smell, is refreshing and not monotonous.

[0028] This invention is conducive to the further development of the chestnut industry, fills the gap in domestic chestnut - processed distilled liquor, enriches the varieties of distilled liquor in our country, increases product diversification, and has important economic value and social significance. Brief Description of the Drawings

[0029] Figure 1 The following shows the process flow chart of the present invention.

[0030] Figure 2 The following shows the process flow chart of the four - enzyme three - stage saccharification process. Detailed Embodiments

[0031] The present invention will be described in detail below with reference to the drawings and specific embodiments:

[0032] The yeast used in the present invention is Saccharomyces cerevisiae, spark, purchased from laffort company in France.

[0033] α - amylase, protease, and glucoamylase are purchased from NOVOZYMES / Novozymes company.

[0034] Example 1

[0035] A preparation method of a fruity - flavored chestnut distilled liquor is as follows:

[0036] (1) Baking and shelling:

[0037] ① Screening: Select fresh chestnuts that are mature, free from mildew and dust.

[0038] ② Baking and shelling: Bake at 180 °C for 40 min, then remove the shell and skin to obtain chestnut kernels. During the baking process, due to the Maillard reaction of reducing sugars and proteins, reducing ketones, aldehydes and heterocyclic compounds are generated, which are the substrates and sources of flavor substances in the subsequent products.

[0039] (2) Preparation of chestnut saccharified juice

[0040] ① Crushing and slurrying: Crush the chestnut kernels with a crusher, add water to adjust the slurry according to a ratio of 1:2.5, and adjust the pH value of the slurry to 5.2 - 5.4.

[0041] ② Saccharification I: Add α - amylase, heat up to 90 °C, keep warm for 30 min for gelatinization and liquefaction. Stir continuously during this period, measure the reaction of iodine and starch, and when no blue color appears, all starch is converted.

[0042] ③ Saccharification II: Cool down to 52 °C, add protease, and keep warm for 30 min. 52 °C is the optimal reaction temperature range for endopeptidase, dipeptidase and carboxypeptidase, which has a positive effect on decomposing proteins into low - molecular - weight nitrogen and amino acids. The increase in α - amino nitrogen content, especially the increase in valine content, can inhibit the production of off - flavor substances such as diacetyl by yeast metabolism, and at the same time reduce the content of higher alcohols in chestnut distilled liquor.

[0043] ④ Saccharification III: Heat up to 63 °C, add β - amylase and glucoamylase, and keep warm for 60 min. 63 °C saccharification is the optimal working temperature of saccharifying enzyme. Starch decomposition produces a large amount of fermentable sugars such as glucose and maltose, providing sufficient carbon sources for yeast and at the same time increasing the liquor yield.

[0044] ⑤ Sugar degree adjustment: Add sterile water to adjust the extract concentration to 14 - 16 °P.

[0045] (3) Fermentation

[0046] ① Yeast addition: When the temperature of the above - mentioned chestnut saccharified juice cools to 20 °C, put it into the tank, add yeast, and the addition amount is 200 g / t saccharified juice, then put it into a stainless - steel barrel for fermentation.

[0047] ② Fermentation monitoring: Measure the temperature and sugar degree of the fermentation broth every 6 hours, and control the fermentation temperature at 18 - 20 °C.

[0048] ③ Fermentation termination: When the sugar degree of the fermentation broth remains unchanged for 24 consecutive hours, terminate the fermentation to obtain the base liquor.

[0049] (4) Distillation

[0050] The secondary distillation method is adopted. The chestnut fermented wine is distilled, the distillate is recovered, and the ethanol content is monitored. When the ethanol content is < 3%, the distillation is stopped, and the crude distillate original wine is obtained by combining. The crude distillate original wine is repeatedly distilled, and the heads and tails are cut off during the distillation process, and the middle fraction is taken.

[0051] (5) Aging

[0052] The distilled original wine is aged in a glass container or a stainless steel container for not less than 24 months;

[0053] (6) Bottling:

[0054] ① Filtration: The original wine with good stability is filtered using a membrane filtration filter;

[0055] ② The filtered original wine is filled, labeled, and packaged.

[0056] The chestnut distilled wine obtained through the above process is clear and transparent in appearance, with complex and rich fruity and winey aromas, mellow and plump taste, harmonious body, and no abnormal smell, having the unique style of chestnut distilled wine.

[0057] The main aroma components in the chestnut distilled wine were identified, and the headspace solid-phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS) method was used to detect the aroma substances in the samples.

[0058] (1) Headspace solid-phase microextraction (HS-SPME)

[0059] The extraction head of the solid-phase microextraction device is aged in the injection port of the gas chromatography, the aging temperature is 250 °C, and the aging time is 1 h. The aged extraction head (DVB / CAR / PDMS) is inserted into the headspace part 1 cm above the liquid level in the sample bottle, and adsorbed for 50 min under the conditions of heating and stirring at 50 °C and 350 rpm, and then the extraction head is taken out and inserted into the injection port of the gas chromatography at 250 °C for thermal desorption for 5 min. Each sample is measured in parallel three times.

[0060] (2) Gas chromatography-mass spectrometry (GC-MS) analysis conditions

[0061] GC conditions: The chromatographic column used is a TG-5SILMS (30 m × 0.25 mm × 0.25 μm) capillary column; the carrier gas is high-purity helium, and the flow rate is 1.2 mL / min. The injection port temperature is 230 °C. The column temperature programming: initial 45 °C, hold for 1 min; increase the temperature to 80 °C at a rate of 4 °C / min, hold for 2 min; increase the temperature to 230 °C at a rate of 5 °C / min, hold for 5 min.

[0062] As shown in the following table:

[0063]

[0064]

[0065] The alcohol content of the product obtained by detecting this invention is 56% vol. A total of 36 volatile aroma components are identified from it. For example, alcohols (isobutanol, isoamyl alcohol, furfuryl alcohol, endowing the chestnut distilled liquor with mellow and floral aromas), esters (ethyl acetate, endowing the light aroma of banana or apple fruits; ethyl octanoate, endowing fruit aroma and brandy aroma; ethyl lactate, endowing floral, fruity and sweet aromas; ethyl cinnamate, endowing strawberry, cream, cinnamon, etc.), aldehydes and ketones (furfural, endowing the soy sauce aroma; benzaldehyde, endowing almond flavor and sweet fruit aroma), etc. It can be seen that the aroma components of the chestnut distilled liquor obtained in this application are relatively complex, and the presented aroma has the characteristics of harmony, uniqueness, richness, etc.

[0066] This method mainly uses chestnuts as the brewing raw material. This invention uses 100% chestnuts as the raw material, and the Maillard reaction during baking produces ketone and aldehyde flavor substances. At the same time, a four-enzyme preparation three-stage saccharification process is adopted to produce abundant fermentable sugars and amino acids, providing substrates for yeast metabolism, and the content of flavor substances produced by fermentation metabolism is relatively high. No flavoring and flavor substances are added in the production process. The produced chestnut distilled liquor contains abundant flavor substances, such as ethyl octanoate with brandy aroma, ethyl lactate with floral, fruity and sweet aromas, ethyl acetate which is the main flavor substance of the light-aroma Baijiu with banana or apple aroma. At the same time, the content of furfural in the distilled liquor is relatively high, and the liquor body also contains a faint soy sauce aroma. The complex flavor substances effectively enrich the flavor of the chestnut distilled liquor, making up for the defect of insufficient aroma of distilled liquor made from a single raw material. The produced chestnut distilled liquor has the unique elegant and harmonious flower and fruit aroma and strong liquor aroma of chestnuts, and at the same time contains a faint soy sauce aroma.

Claims

1. A preparation method of a chestnut distilled liquor with fruity flavor, characterized in that, In the preparation method, saccharification is carried out by a three-stage saccharification method: ① Crushing and slurry preparation: The chestnut kernels are crushed by a crusher, and water is added for slurry preparation according to a ratio of 1:2.5, and the pH value of the slurry is adjusted to 5.2 - 5.4; ② First saccharification: Add α-amylase, heat up to 90 °C, keep warm for 30 min, gelatinize and liquefy, continuously stir during this period, measure the reaction of iodine with starch, and when there is no blue color showing, all starch is converted; ③ Second saccharification: Cool down to 52 °C, add protease, and keep warm for 30 min; 52 °C is the optimal reaction temperature range for endopeptidase, dipeptidase and carboxypeptidase, which has a positive effect on decomposing proteins into low-molecular nitrogen and amino acids. The increase in valine content can inhibit the bad flavor substances produced by yeast metabolism, and at the same time reduce the content of higher alcohols in chestnut distilled liquor; ④ Third saccharification: Heat up to 63 °C, add β-amylase and glucoamylase, and keep warm for 60 min; 63 °C is the optimal working temperature of glucoamylase, and a large amount of fermentable sugars are produced by starch decomposition. The fermentable sugars include glucose and maltose, which provide sufficient carbon sources for yeast and at the same time increase the liquor yield; ⑤ Sugar degree adjustment: Add sterile water to adjust the extract concentration to 14 - 16 °P; The chestnut distilled liquor contains 36 kinds of volatile aroma components.

2. The preparation method of a fruity flavor chestnut distilled liquor according to claim 1, characterized in that, After saccharification in the preparation method, the subsequent steps are: fermentation, distillation, aging, and canning in sequence.

3. The preparation method of a fruity flavor chestnut distilled liquor according to claim 2, characterized in that, The specific steps of the fermentation are as follows: ① Yeast addition: When the temperature of the chestnut saccharified juice obtained after saccharification is cooled to 20 °C, it is put into the tank, yeast is added, and the addition amount is 200 g / t of saccharified juice, and then it is put into a stainless steel barrel for fermentation; ② Fermentation monitoring: Measure the temperature and sugar degree of the fermentation broth every 6 hours, and control the fermentation temperature at 18 - 20 °C; ③ Fermentation termination: When the sugar degree of the measured fermentation broth has not changed for 24 consecutive hours, the fermentation is terminated to obtain the base liquor.

4. The preparation method of a chestnut distilled liquor with fruity flavor according to claim 2, characterized in that , The distillation steps are as follows: The chestnut fermented liquor is distilled by a two-stage distillation method, the distillate is recovered, and the ethanol content is monitored. When the ethanol content < 3%, the distillation is stopped, and the obtained rough-distilled original liquor is combined and distilled repeatedly. During the distillation process, the heads and tails are cut off, and the middle fraction is taken.

5. The preparation method of a fruity flavor chestnut distilled liquor according to claim 2, characterized in that, The aging steps are as follows: The distilled original liquor is aged in a glass container or a stainless steel container for not less than 24 months.

6. The preparation method of a fruity-flavored chestnut distilled liquor according to claim 2, characterized in that, The canning steps are as follows: ① Filtration: Filter the original liquor with good stability using a membrane filtration filter; ② The filtered original liquor is canned, labeled, and packaged.

7. The preparation method of a fruity flavor chestnut distilled liquor according to claim 1, characterized in that, Before saccharification in the preparation method, the steps are: baking and shelling: ① Screening: Select fresh chestnuts that are mature, free from mildew and dust; ② Baking and shelling: Bake at 180 °C for 40 min, and remove the shell and skin to obtain chestnut kernels.

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