Chinese chestnut and kiwi fruit peptide wine and preparation method thereof

Abstract

The invention discloses Chinese chestnut and kiwi fruit peptide wine and a preparation method thereof, and belongs to the field of fruit wine brewing. Chinese chestnut raw pulp added with sulfur dioxide and dry ice is cured by adopting a bubbling-quick freezing-variable temperature grinding mode, so that browning and oxidation are greatly reduced, the content of resistant starch is reduced, and the content of nutrient substances and the utilization rate of sugar are increased; meanwhile, in the brewing process, kiwi fruit pulp is used for adjusting the pH, the sugar degree and the flavor of chestnut pulp, and side reactions are controlled. The Chinese chestnut and kiwi fruit peptide wine disclosed by the invention is rich in nutrition and taste, does not contain exogenous sugar and organic acid, is simple in preparation process and has relatively high production value.

Description

Technical Field

[0001] The invention relates to the field of fruit wine brewing, and in particular to chestnut and kiwifruit peptide wine and a preparation method thereof. Background Art

[0002] Chestnut is a nut-rich food with a carbohydrate content of 40-50%. It also contains protein, fat, vitamin C, calcium, phosphorus and other nutrients, and has certain medicinal value. Due to its high sugar content, especially starch content, chestnut can be used as a raw material for winemaking, which is generally produced according to the grain wine process, or as an auxiliary material to provide unique flavor and nutrition. However, the processing technology of fruit wine with chestnut as the main sugar source is not yet mature.

[0003] The Chinese invention with the announcement number CN1255524C discloses a method for preparing chestnut wine and an anti-browning composition, wherein chestnut kernels are pulped, saccharified, and then inoculated with brewer's yeast, and chestnut wine is obtained after fermentation and aging, wherein an anti-browning composition containing sulfur dioxide is also used, which reduces the loss of reducing sugar, protein and amino acids during processing by inhibiting enzymatic browning and carbonyl-amine browning. However, the carbohydrates of chestnuts are mainly starch, of which the more difficult to saccharify straight-chain starch accounts for about 30% of the total starch, which is higher than the common starchy raw materials for brewing, which will lead to reduced fermentation efficiency and insufficient wine yield.

[0004] Adding some sugary raw materials such as medium- and high-sugar fruits during the starchy raw material brewing process can increase the content of soluble sugar in the saccharified mash, improve fermentation efficiency, and bring a unique fruity aroma. The Chinese invention with announcement number CN113930306A discloses a sorghum passion fruit raw material brewing method, which improves the saccharification conversion rate and wine yield by adding passion fruit juice to the sorghum wine brewing, and combines the flavors of sorghum wine and passion fruit.

[0005] There are some chestnut + fruit wine production processes in the prior art, such as a mint chestnut wine and its home preparation method disclosed in China Invention Announcement No. CN104152308B, and a preparation method of chestnut kiwi peptide wine disclosed in China Invention Announcement No. CN105695271A; but these patented technologies all extract part of the flavor and nutrients by soaking the original wine, and do not organically combine the application of starchy raw materials and sugary raw materials in the brewing process. In fact, fruit raw materials often contain more organic acids and reducing components, which can be solutions to some problems in the production of chestnut wine. Summary of the invention

[0006] To overcome the deficiencies of the prior art, the present invention provides a chestnut kiwi peptide wine and a preparation method thereof, which reduces side reactions and improves the gelatinization rate of starch in the ripening step of raw chestnut pulp, and uses kiwi pulp to adjust the chemical properties and flavor of chestnut pulp during the brewing process.

[0007] One of the purposes of the present invention is to provide a method for preparing chestnut kiwifruit peptide wine, comprising the following steps:

[0008] (1) peeling and crushing fresh mature chestnuts, and mixing the resulting chestnut kernels with water to obtain raw chestnut pulp;

[0009] (2) introducing sulfur dioxide into raw chestnut pulp, adding dry ice to quickly freeze the raw pulp, and then grinding at low temperature. After the raw pulp is thawed by the heat generated by grinding, it is heated to 85-100° C. and further ground to obtain mature pulp;

[0010] (3) adding calcium reagent and α-amylase to the cooked pulp to liquefy it and inactivate the enzyme to obtain a liquefied pulp;

[0011] (4) adding kiwifruit pulp and saccharifying enzyme to the liquefied pulp for saccharification, inactivating the enzyme, and obtaining saccharified pulp;

[0012] (5) adding casein and acid protease to the saccharified slurry for enzymolysis, and then directly adding brewer's yeast, fermenting at 12-20° C. for 7-10 days, filtering, clarifying, and sterilizing to obtain the chestnut kiwi peptide wine.

[0013] The second object of the present invention is to provide a chestnut kiwi peptide wine prepared according to the above preparation method, wherein the alcohol content is 7.0-10.0% Vol.

[0014] The technical solution of the present invention has the following beneficial effects:

[0015] 1. The preparation method of the chestnut kiwi peptide wine of the present invention adopts a physical foaming-quick freezing-variable temperature grinding and a chemical acidification and antioxidant method to treat the ripe chestnut raw pulp, while the content of reducing sugar, amino acids, proteins, vitamin C and other nutrients is not affected, and the resistant starch in the raw pulp is fully converted into non-resistant starch that is easily degraded by enzymes, thereby improving the utilization rate of the raw material sugar.

[0016] 2. In the preparation method of chestnut kiwi peptide wine described in the present invention, kiwi pulp rich in soluble sugars, organic acids and reducing substances is used to adjust the pH and sugar content of the chestnut pulp and protect it from browning, thereby reducing the addition of exogenous chemicals such as acid and sucrose, and improving the fermentation degree and flavor of the product. DETAILED DESCRIPTION

[0017] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, the specific implementation of the present invention is further described below. Obviously, the embodiments described therein are only part of the implementation of the present invention, which is an explanation of the technical solution of the present invention rather than a limitation.

[0018] The present invention discloses a method for preparing chestnut kiwifruit peptide wine, comprising the following steps:

[0019] (1) peeling and crushing fresh mature chestnuts, and mixing the resulting chestnut kernels with water to obtain raw chestnut pulp;

[0020] (2) introducing sulfur dioxide into raw chestnut pulp, adding dry ice to quickly freeze the raw pulp, and then grinding at low temperature. After the raw pulp is thawed by the heat generated by grinding, it is heated to 85-100° C. and further ground to obtain mature pulp;

[0021] (3) adding calcium reagent and α-amylase to the cooked pulp to liquefy it and inactivate the enzyme to obtain a liquefied pulp;

[0022] (4) adding kiwifruit pulp and saccharifying enzyme to the liquefied pulp for saccharification, inactivating the enzyme, and obtaining saccharified pulp;

[0023] (5) adding casein and acid protease to the saccharified slurry for enzymolysis, and then directly adding brewer's yeast, fermenting at 12-20° C. for 7-10 days, filtering, clarifying, and sterilizing to obtain the chestnut kiwi peptide wine.

[0024] Furthermore, the mass ratio of the crushed chestnut kernel to water in step (1) is 3:(7-12), that is, the mass fraction of the chestnut kernel to the raw chestnut pulp is 20-30%.

[0025] Furthermore, the amount of sulfur dioxide added in step (2) is limited to a pH value of chestnut pulp of 3.5 to 4.0; the time of low-temperature grinding is not less than 10 minutes, and the time of heating and continued grinding is between 20 and 40 minutes.

[0026] The addition of sulfur dioxide in this step has three functions: adjusting the pH value of the slurry, creating a reducing environment, and bubbling in the slurry to facilitate grinding after quick freezing. The first two are to inhibit the browning of chestnuts and reduce the loss of nutrients. It is worth noting that the large amount of carbon dioxide produced by dry ice is also acidic, so the amount of sulfur dioxide can be reduced accordingly.

[0027] Furthermore, the calcium reagent in step (3) is a mixture of calcium hydroxide and calcium chloride, and its addition amount is limited to the pH of the mature pulp reaching 6.0-7.0 and the calcium content reaching 50-100 ppm; based on the mass of the mature pulp, the addition amount of the α-amylase is 200-500 U / g.

[0028] It is a well-known prior art to add an appropriate amount of calcium ions to the working environment of α-amylase to improve its activity and stability; further, replacing part of the calcium chloride with calcium hydroxide can effectively absorb the excess sulfur dioxide in the previous step and adjust the slurry pH to the optimal range of α-amylase.

[0029] Furthermore, the amount of kiwifruit pulp added in step (4) is limited to a pH value of liquefied pulp of 4.0 to 4.5; and the amount of saccharifying enzyme added is 2000 to 4000 U / g based on the mass of liquefied pulp.

[0030] Furthermore, the kiwifruit pulp is prepared by the following steps: peeling and pulping the kiwifruit, adding 70-100 mg / L of sulfur dioxide, and then adding 0.5-1.0 U / g of pectinase for enzymolysis and enzyme inactivation to obtain the kiwifruit pulp. Preferably, the kiwifruit is a ripe kiwifruit that has been post-ripened, and the soluble solid content is not less than 14.0%.

[0031] The pH of the kiwifruit pulp prepared according to the steps is between 3.0 and 3.5, and the amount added is calculated to be about 3-30% of the mass of the liquefied pulp, preferably 10-15%, that is, the mass ratio of the chestnut kiwifruit raw materials is about 2:1.

[0032] Furthermore, in step (5), based on the mass of saccharified slurry, the amount of casein added is 2.0 to 7.5 g / kg, and the amount of acid protease added is 5 to 20 U / g.

[0033] Studies have shown that casein is rich in alanine (4.4%), valine (6.3%) and leucine (9.1%) that increase yeast fermentation rate, as well as valine, leucine, threonine (4.4%) and phenylalanine (4.1%) that promote yeast production of flavoring acid esters. In addition, casein has low levels of sulfur-containing amino acids cysteine ​​(0.4%) and methionine (2.6%) that inhibit yeast growth, making it very suitable as a supplementary nitrogen source for yeast growth. Acidic protease can decompose the added casein and the inherent proteins in chestnuts and kiwis, providing rich amino acids and small molecule peptide nutrition for fruit wine.

[0034] Furthermore, in step (5), the amount of brewer's yeast added is 0.2-0.5 g / kg based on the mass of saccharified slurry; preferably, the brewer's yeast model is EC1118. Considering the comprehensive SO2 resistance, fermentation efficiency, fermentation aroma and other factors, this model of yeast is relatively excellent.

[0035] The chestnut kiwifruit peptide wine prepared by the preparation method disclosed in the present invention has an alcohol content of 7.0-10.0% Vol. This range refers to the alcohol content range of the chestnut kiwifruit original wine without subsequent post-fermentation, aging and other treatments.

[0036] The present invention is described in detail below with reference to the examples. The experimental methods are conventional methods unless otherwise specified; the reagents and materials are commercially available unless otherwise specified; the serial numbers used are only for dividing the steps and do not strictly represent the order of operation.

[0037] Example 1

[0038] Prepare chestnut kiwi peptide wine as follows:

[0039] (1) Peel and crush fresh mature chestnuts to obtain 1 kg of chestnut kernels, which are then mixed with 3 kg of water to obtain raw chestnut pulp.

[0040] (2) The obtained chestnut raw pulp was cooled to 4°C, sulfur dioxide was bubbled into it until the pH reached 3.8, and then 1.5 kg of dry ice was added to freeze the raw pulp to -24°C within 30 seconds. After grinding for 15 minutes, the raw pulp temperature reached 3°C, and then heated to 90°C and continued to grind for 30 minutes. During the process, the amount of water was kept unchanged to obtain mature pulp.

[0041] (3) Add 0.1 g of calcium hydroxide, 0.3 g of calcium chloride and 1.6 million U of α-amylase to the obtained mature pulp, liquefy at 65° C. for 2 h, inactivate the enzyme, and obtain liquefied pulp.

[0042] (4) After ripening kiwifruit with a soluble solid content of 14.3% was peeled and pulped to obtain 0.5 L of kiwifruit pulp, to which 40 mg of sulfur dioxide and 5,000 U of pectinase were added, and the mixture was enzymolyzed at 35°C for 2 h to inactivate the enzyme, thereby obtaining kiwifruit pulp with a pH of 3.2.

[0043] (5) 4 kg of the obtained liquefied pulp was mixed with 0.5 kg of the obtained kiwi pulp to obtain a pulp with a pH of 4.2, and then 13 million U of saccharifying enzyme was added. The mixture was saccharified at 60°C for 48 hours, and the enzyme was inactivated to obtain saccharified pulp.

[0044] (6) Add 25 g of casein and 50,000 U of acid protease to the obtained saccharification slurry, keep warm at 45° C. for 4 h, then directly add 2.7 g of brewer's yeast EC1118, ferment at 16° C. for 8 days, filter, clarify and sterilize to obtain the chestnut kiwi peptide wine with an alcohol content of 8.6% Vol.

[0045] Example 2

[0046] Prepare chestnut kiwi peptide wine as follows:

[0047] (1) Peel and crush fresh mature chestnuts to obtain 1 kg of chestnut kernels, which are then mixed with 2.4 kg of water to obtain raw chestnut pulp.

[0048] (2) The obtained chestnut pulp is cooled to 4°C, sulfur dioxide is bubbled into it until the pH reaches 4.0, and then 2 kg of dry ice is added to freeze the pulp to -31°C within 30 seconds. After grinding for 20 minutes, the pulp temperature reaches 3°C, and it is heated to 85°C and continued to be ground for 35 minutes. During the process, the amount of water is kept unchanged to obtain mature pulp.

[0049] (3) Add 0.1 g of calcium hydroxide, 0.3 g of calcium chloride and 1.2 million U of α-amylase to the obtained mature pulp, liquefy at 65° C. for 2 h, inactivate the enzyme, and obtain liquefied pulp.

[0050] (4) After ripening kiwifruit with a soluble solid content of 14.3% was peeled and pulped to obtain 0.5 L of kiwifruit pulp, to which 50 mg of sulfur dioxide and 0.5000 U of pectinase were added, and the mixture was enzymolyzed at 35°C for 2 h to inactivate the enzyme, thereby obtaining kiwifruit pulp with a pH of 3.2.

[0051] (5) 4 kg of the obtained liquefied pulp was mixed with 0.6 kg of the obtained kiwi pulp to obtain a pulp with a pH of 4.0, and then 15 million U of saccharifying enzyme was added. The mixture was saccharified at 65° C. for 36 hours, and the enzyme was inactivated to obtain saccharified pulp.

[0052] (6) Add 30 g of casein and 80,000 U of acid protease to the obtained saccharification slurry, keep warm at 40° C. for 6 h, then directly add 3.0 g of brewer's yeast EC1118, ferment at 14° C. for 10 days, filter, clarify and sterilize to obtain the chestnut kiwi peptide wine with an alcohol content of 9.7% Vol.

[0053] Comparative Example 1

[0054] The only difference between the method for preparing chestnut and kiwi wine in this comparative example and that in Example 1 is that no dry ice is added after sulfur dioxide is introduced in step (2), and the temperature is directly raised to 90° C. and ground for 60 min.

[0055] Comparative Example 2

[0056] The only difference between the method for preparing chestnut and kiwi wine in this comparative example and that in Example 1 is that sulfur dioxide is not introduced in step (2), and the pH of the slurry after adding dry ice is 5.6.

[0057] Comparative Example 3

[0058] The only difference between the method for preparing chestnut and kiwi wine in this comparative example and that in Example 1 is that in step (2), neither sulfur dioxide is introduced nor dry ice is added for grinding, and the wine is directly boiled at 100° C. for 1 h, and the amount of water is kept unchanged during the process.

[0059] Comparative Example 4

[0060] The only difference between the method for preparing chestnut kiwi wine in this comparative example and that in Example 1 is that kiwi pulp is not added in step (5) (naturally, step (4) is not required), and citric acid is used instead to adjust the pH to 4.2.

[0061] The chestnut kiwi peptide wines obtained in the above embodiments and comparative examples were tested below.

[0062] 1. Determination of browning degree and total amount of amino acid protein

[0063] The color of chestnut kiwi peptide wine was determined by spectrophotometry, which was expressed as the sum of absorbance values ​​at pH 3.4, 420nm, 520nm, and 620nm; the free amino acid and polypeptide contents of chestnut kiwi peptide wine were determined by formaldehyde titration and BCA method, respectively. The results are shown in Table 1.

[0064] Table 1 Chroma, amino acid and peptide contents of chestnut kiwi peptide wine

[0065] Group Chroma Amino Acid (mg / L) Peptide(g / L) Example 1 0.75 682 5.35 Example 2 0.86 811 5.78 Comparative Example 1 0.77 620 5.29 Comparative Example 2 3.54 212 2.64 Comparative Example 3 3.82 198 2.32 Comparative Example 4 0.41 537 4.81

[0066] 2. Starch residue

[0067] The residual starch content in chestnut kiwifruit peptide wine was determined by iodine titration, and the residual sulfur dioxide content in chestnut kiwifruit peptide wine was determined by ion chromatography. The results are shown in Table 2.

[0068] Table 2 Starch and sulfur dioxide residues in chestnut kiwi peptide wine

[0069] Group Starch (g / L) Sulfur dioxide (mg / L) Example 1 0.13 24.5 Example 2 0.12 31.7 Comparative Example 1 1.28 25.1 Comparative Example 2 0.45 10.3 Comparative Example 3 2.63 9.7 Comparative Example 4 0.11 15.8

[0070] Although yeast has a certain ability to degrade resistant starch, the chestnut kiwi peptide wine obtained in the comparative example without complete freeze-grinding still has obvious starch residues. Some studies believe that sulfur dioxide will protect starch granules during hydrolysis, but in the freeze-grinding environment of the technical solution described in the present invention, no such negative impact of sulfur dioxide was observed.

[0071] Although a large amount of sulfur dioxide is used in the processing, the residual sulfur dioxide content of the chestnut kiwi peptide wine of the present invention is significantly lower than the maximum allowable amount (150 mg / L), and even for the purpose of preservation, some sulfur dioxide can be added to the produced peptide wine.

[0072] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description, and the obvious changes or modifications derived therefrom should still be considered as the protection scope of the present invention.

Claims

1. A method for preparing chestnut kiwi peptide wine, characterized in that: The steps include: (1) peeling and crushing fresh mature chestnuts, and mixing the resulting chestnut kernels with water to obtain raw chestnut pulp; (2) introducing sulfur dioxide into raw chestnut pulp, adding dry ice to quickly freeze the raw pulp, and then grinding at low temperature. After the raw pulp is thawed by the heat generated by grinding, it is heated to 85-100° C. and further ground to obtain mature pulp; (3) adding calcium reagent and α-amylase to the cooked pulp to liquefy it and inactivate the enzyme to obtain a liquefied pulp; (4) adding kiwifruit pulp and saccharifying enzyme to the liquefied pulp for saccharification, inactivating the enzyme, and obtaining saccharified pulp; (5) adding casein and acid protease to the saccharified slurry for enzymolysis, and then directly adding brewer's yeast, fermenting at 12-20° C. for 7-10 days, filtering, clarifying, and sterilizing to obtain the chestnut kiwi peptide wine.

2. The method for preparing chestnut kiwifruit peptide wine according to claim 1, characterized in that: In step (1), the mass ratio of the crushed chestnut kernel to water is 3:(7-12).

3. The method for preparing chestnut kiwifruit peptide wine according to claim 1, characterized in that: In step (2), the amount of sulfur dioxide added is limited to a pH value of chestnut pulp of 3.5 to 4.0; the low-temperature grinding time is not less than 10 minutes, and the heating and continued grinding time is between 20 and 40 minutes.

4. The method for preparing chestnut kiwifruit peptide wine according to claim 1, characterized in that: In step (3), the calcium reagent is a mixture of calcium hydroxide and calcium chloride, and its addition amount is limited to the pH of the mature pulp reaching 6.0-7.0 and the calcium content reaching 50-100 ppm; based on the mass of the mature pulp, the addition amount of the α-amylase is 200-500 U / g.

5. The method for preparing chestnut kiwifruit peptide wine according to claim 1, characterized in that: In step (4), the amount of kiwifruit pulp added is limited to a pH value of 4.0 to 4.5 of the liquefied pulp; and the amount of saccharifying enzyme added is 2000 to 4000 U / g based on the mass of the liquefied pulp.

6. The method for preparing chestnut kiwi peptide wine according to claim 5, characterized in that: The kiwifruit pulp is prepared according to the following steps: The kiwi fruit is peeled and pulped, sulfur dioxide is added at 70-100 mg / L, and then pectinase is added at 0.5-1.0 U / g for enzymolysis and enzyme inactivation to obtain the kiwi fruit pulp.

7. The method for preparing chestnut kiwifruit peptide wine according to claim 6, characterized in that: The kiwi fruit is a mature kiwi fruit that has been post-ripened and has a soluble solid content of not less than 14.0%.

8. The method for preparing chestnut kiwifruit peptide wine according to claim 1, characterized in that: In step (5), based on the mass of saccharified slurry, the added amount of casein is 2.0 to 7.5 g / kg, and the added amount of acid protease is 5 to 20 U / g.

9. The method for preparing chestnut kiwifruit peptide wine according to claim 1, characterized in that: In step (5), the amount of brewer's yeast added is 0.2-0.5 g / kg based on the mass of saccharification slurry; preferably, the brewer's yeast model is EC1118.

10. A chestnut and kiwifruit peptide wine prepared by the preparation method according to claims 1 to 9, characterized in that: The alcohol content of the chestnut kiwi peptide wine is 7.0-10.0% Vol.