Gluten-free kvass low-alcohol beverage and preparation technology thereof

Abstract

The invention provides a gluten-free kvass low-alcohol beverage and a preparation technology thereof, and belongs to the technical field of beverage processing. Comprising the following steps: (1) selecting gluten-free grains, baking, cooling, adding water and cooking; (2) cooling, grinding into thick liquid, adding a compound enzyme for enzymolysis, and boiling for enzyme deactivation to obtain saccharified liquid; and (3) inoculating and fermenting to obtain the gluten-free kvass low-alcohol beverage. The compound enzyme is composed of alpha-amylase and saccharifying enzyme according to a mass ratio of 1: 4-1: 8. The raw materials used in the invention are not traditional raw materials for preparing kvass, but gluten-free grains are used, and the obtained product does not contain gluten, has the flavor similar to that of kvass and the characteristics of low alcohol (less than 1.2% vol), and is especially suitable for crowds allergic to gluten.

Description

Technical Field

[0001] This invention relates to the field of beverage processing technology, and in particular to a gluten-free, low-alcohol kvass-like beverage and its preparation process. Background Technology

[0002] Kvass, also known as kvass, is a traditional fermented beverage originating in Russia. It is currently brewed primarily with malt (mainly barley malt, wheat malt, rye malt, etc.) with or without other grains. These grains contain a large amount of gluten protein. Gluten is a type of storage protein found in crops such as wheat, barley, and rye. For people with celiac disease or gluten sensitivity, it can cause intestinal inflammation, diarrhea, malnutrition, and even more serious autoimmune reactions. Therefore, this application aims to provide a gluten-free beverage with a kvass-like flavor by adjusting the ingredients, thus addressing the issue of kvass being unsuitable for people with gluten allergies.

[0003] However, simple raw material substitution cannot directly yield the desired product. Malt contains a large amount of α-amylase and β-amylase. When saccharified with malt, its own hydrolytic enzymes, along with the action of water and heat, can break down the insoluble high-molecular-weight substances (starch, protein, hemicellulose, phytates, etc.) in malt into soluble low-molecular-weight substances (such as sugars, dextrins, amino acids, peptides, etc.). In contrast, gluten-free grains such as rice or brown rice typically have low or no amylase activity. If traditional malt saccharification processes are used, relying on endogenous enzymes for saccharification often leads to incomplete saccharification and insufficient fermentable sugar content, thus affecting subsequent fermentation efficiency and the fullness of the beverage's flavor. Therefore, to address the problem of low saccharification efficiency of gluten-free raw materials, this application aims to develop a kvass-like beverage preparation process by improving its saccharification process. This process not only adapts to the characteristics of gluten-free raw materials but also balances saccharification efficiency and flavor formation. Summary of the Invention

[0004] The purpose of this invention is to provide a gluten-free, low-alcohol kvass-like beverage.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a process for preparing a gluten-free, low-alcohol kvass-like beverage, comprising the following steps: (1) Select gluten-free grains, bake, cool, and steam with water; (2) Cool, grind into a paste, add compound enzyme for enzymatic hydrolysis, boil to inactivate the enzyme, and obtain saccharified liquid; (3) Inoculation and fermentation, to obtain the gluten-free kvass-like low-alcohol beverage; The compound enzyme is composed of α-amylase and saccharifying enzyme in a mass ratio of 1:4 to 1:8.

[0006] Preferably, the gluten-free grain is selected from white rice, brown rice, or broken rice.

[0007] Preferably, the baking temperature is 100~200℃ and the baking time is 30min~180min.

[0008] Preferably, in step (1), water is added at a ratio of 1g to (1~1.2)mL during steaming, and the mixture is steamed for 30~50min.

[0009] Preferably, in step (2), water is added at a ratio of 1g:(4~6)mL during grinding.

[0010] Preferably, the amount of the compound enzyme added is 2% to 5%; Enzymatic hydrolysis and saccharification conditions: pH 6.0~8.0, temperature 45℃~75℃, time 10h~15h.

[0011] The present invention also provides a gluten-free, low-alcohol kvass-like beverage prepared by the above preparation method.

[0012] This invention improves the saccharification process in the preparation of low-alcohol kvass beverages by selecting the best combination of complex enzymes for saccharification, resulting in a gluten-free low-alcohol kvass-like beverage. The raw materials used in this invention are not traditional kvass ingredients such as bread or malt, but rather gluten-free grains such as rice, brown rice, and broken rice. The product contains no gluten, has a kvass-like flavor, and is low in alcohol (<1.2% vol). It has a golden-yellow appearance, uniform color, is transparent and clear, with little or no sediment, and has a distinct rice and hop aroma. The taste is moderately sweet and sour with a lingering aftertaste and a bubbly texture, making it especially suitable for people with gluten allergies. Attached Figure Description

[0013] Figure 1 The effect of α-amylase addition on the saccharification effect of broken rice.

[0014] Figure 2 The effect of the amount of saccharifying enzyme added on the saccharification effect of broken rice.

[0015] Figure 3 The effect of baking temperature on the sensory evaluation of kvass-like low-alcohol beverages.

[0016] Figure 4 The effect of baking time on the sensory evaluation of kvass-like low-alcohol beverages. Detailed Implementation

[0017] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0018] Example 1: A gluten-free, low-alcohol kvass-like beverage, prepared by the following method: Brown rice was baked at 200℃ for 30 minutes, cooled to room temperature (25℃), and water was added at a ratio of 1g:1.2mL. The mixture was steamed for 40 minutes and cooled. 60g of cooked brown rice was then ground into a slurry with water at a ratio of 1g:4mL. A compound enzyme (composed of α-amylase and saccharifying enzyme in a ratio of 1:8, with an addition amount of 2%, saccharifying enzyme (150000u / g) and α-amylase (50000u / g) were both purchased from Henan Wanbang Industrial Co., Ltd.) was added. The mixture was saccharified at 45℃ for 12 hours, boiled for 5 minutes to inactivate the enzyme, and cooled to room temperature to obtain brown rice saccharified slurry (the DE value of the obtained saccharified slurry was 6.7%, and the soluble solids content was 9.5%). Then add 0.1g / 100g of dry hops, boil for 5 minutes, cool to room temperature, take 0.2g / 100g of dry yeast, activate and expand it, then inoculate it into the syrup, ferment at 18℃ for 5 days, and the resulting product has an alcohol content of 0.962% vol.

[0019] Example 2: A gluten-free, low-alcohol kvass-like beverage, prepared by the following method: Rice was baked at 180℃ for 50 minutes, cooled to room temperature, and water was added at a ratio of 1:1.1 (material to liquid). The rice was then steamed for 40 minutes and cooled again. 80g of the cooked rice was taken, and water was added at a ratio of 1:6 (material to liquid) to grind it into a slurry. A compound enzyme (composed of α-amylase and saccharifying enzyme in a 1:6 ratio, added at 5%) was added, and saccharification was carried out at 60℃ for 11 hours. The enzyme was then inactivated by boiling for 5 minutes and cooled to room temperature to obtain a rice saccharification slurry (the DE value of the saccharified slurry was 8.0%, and the soluble solids content was 11.3%). Then, 0.1g / 100g of dried hops was added, and the slurry was boiled for 5 minutes and cooled to room temperature. Dry yeast was taken at a ratio of 0.2g / 100g, activated, expanded, and inoculated into the slurry. Fermentation was carried out at 18℃ for 6 days, resulting in a product with an alcohol content of 1.002% vol.

[0020] Example 3: A gluten-free, low-alcohol kvass-like beverage, prepared by the following method: Broken rice was baked at 100℃ for 60 minutes, cooled to room temperature, and water was added at a ratio of 1:1 (material to liquid). The mixture was steamed for 40 minutes, cooled, and then 60g of cooked broken rice was taken and ground into a slurry with water at a ratio of 1:5 (material to liquid). A compound enzyme (composed of α-amylase and saccharifying enzyme in a 1:4 ratio, added at 3%) was added, and saccharification was carried out at 70℃ for 10 hours. The enzyme was then inactivated by boiling for 5 minutes, and cooled to room temperature to obtain a saccharified rice slurry (the DE value of the saccharified slurry was 8.4%, and the soluble solids content was 10.6%). Then, 0.1g / 100g of dried hops was added, boiled for 5 minutes, cooled to room temperature, and 0.2g / 100g of dried yeast was taken, activated, expanded, and inoculated into the syrup. Fermentation was carried out at 18℃ for 6 days, yielding a product with an alcohol content of 1.120% vol.

[0021] Example 4

[0022] Unlike Example 3, the broken rice was baked at 140°C for 120 minutes.

[0023] Experimental Example 1

[0024] To study the saccharification effect of different combinations of compound enzymes, the following experimental groups were set up. The preparation process was the same as in Example 4. The DE value and solid content were determined according to GB / T 20882-2021 "Quality Requirements for Starch Sugars Part 2: Glucose Syrup (Powder)". Saccharifying enzyme (150,000 u / g) and α-amylase (50,000 u / g) were purchased from Henan Wanbang Industrial Co., Ltd.; β-amylase (50,000 u / g) was purchased from Shandong Kete Enzyme Preparation Co., Ltd.; pullulanase (100,000 u / g) was purchased from Zhejiang Tianhe Food Biotechnology Co., Ltd. (1) α-Amylase + β-Amylase (mass ratio 1:1); (2) α-Amylase + saccharifying enzyme (mass ratio 1:1); (3) α-Amylase + pullulanase (mass ratio 1:1); (4) α-Amylase + β-Amylase + Pullulanase (mass ratio 1:1:1); (5) α-Amylase + glucoamylase + pullulanase (mass ratio 1:1:1): (6) α-Amylase + β-amylase + saccharifying enzyme (mass ratio 1:1:1); Table 1. Glycosylation effect of different combinations of enzymes

[0025] As shown in Table 1, compared to a single α-amylase system, saccharifying enzymes, β-amylases, or pullulanases all significantly improved the enzymatic hydrolysis efficiency of α-amylase, exhibiting a clear synergistic effect. Therefore, β-amylase, saccharifying enzymes, pullulanases, and α-amylases were selected for binary and ternary complex saccharification. The study found that under the same conditions, the soluble solids content of each complex enzyme group was similar, while the α-amylase + saccharifying enzyme binary complex yielded the highest DE value, indicating that the synergistic effect between saccharifying enzymes and α-amylase is stronger and the saccharification effect is best when macromolecular enzymatic hydrolysis is reduced to small reducing sugar molecules. Considering all factors, α-amylase and saccharifying enzymes were selected as the complex enzymes.

[0026] Experiment Example 2: Effect of Different Enzyme Addition Amounts on Saccharification Efficiency

[0027] (1) In order to study the saccharification effect of different amounts of α-amylase, α-amylase + saccharifying enzyme were added according to the results obtained in Experiment 1. 1g of saccharifying enzyme was added, and then 0.1g, 0.3g, 0.6g, 0.9g, 1.2g, and 1.5g of α-amylase were added respectively. The preparation process was the same as in Example 4, and the DE value and solid content were determined by the same method as in Experiment 1.

[0028] (2) In order to study the saccharification effect of different amounts of saccharifying enzyme, α-amylase + saccharifying enzyme were added according to the results obtained in Experiment Example 1. After adding the optimal amount of α-amylase in (1), 0.3g, 0.6g, 0.9g, 1.2g, 1.5g and 1.8g of saccharifying enzyme were added respectively for saccharification. The process was the same as in Example 4, and the DE value and solid content were determined by the same method as in Experiment Example 1.

[0029] Depend on Figure 1 , 2 It can be seen that with the increase of α-amylase addition, both solids and DE value first increased and then decreased and tended to level off. This indicates that with the increase of α-amylase addition, the amount of macromolecular insoluble matter enzymatically hydrolyzed into small molecule soluble matter increases significantly. When the amount of α-amylase added is 0.3g, the DE value is 9.63%. Further increasing the amount of α-amylase added does not significantly change the reducing sugar content and solids content.

[0030] With a fixed α-amylase addition of 0.3g, the DE value slowly increased and then began to decrease with increasing α-amylase addition. The soluble solids content was between 9-10%. The α-amylase accelerated the hydrolysis of starch, producing glucose, thus continuously increasing the reducing sugar content. The DE value reached its maximum of 9.79% when the α-amylase addition was 1.5g.

[0031] Taking all factors into consideration, 0.3g of α-amylase and 1.5g of saccharifying enzyme were added to 60g of cooked rice for saccharification.

[0032] Experimental Example 3: Sensory Evaluation of Broken Rice-Based Low-Alcohol Kvass Beverage

[0033] Take 500g of broken rice raw material and place it in a baking tray in an oven, spread it evenly, and put it in a food-grade drying oven. Set the baking temperature to 80℃, 100℃, 120℃, 140℃, 160℃, 180℃, and 200℃ respectively, and bake for 30min, 60min, 90min, 120min, 150min, and 180min respectively. Process the baked broken rice into a kvass-like low-alcohol beverage according to the method of Example 3 and conduct sensory evaluation to determine the optimal baking temperature and time.

[0034] A sensory evaluation system for low-alcohol kvass-like beverages made from broken rice was established, as shown in Table 2. Ten evaluators trained according to the requirements of GB / T 16291.1-2012 scored the low-alcohol kvass-like beverages made from roasted broken rice fermentation according to the scoring criteria, and the average score was taken as the final score.

[0035] Table 2 Sensory Evaluation System

[0036] like Figure 3 , Figure 4 As shown, within the roasting range of 80℃ to 200℃, as the roasting temperature increases, the color of broken rice gradually changes from white to yellow to dark brown, and the rice aroma gradually intensifies until a burnt smell is produced. The color of the fermented kvass-like low-alcohol beverage changes from opaque white to transparent golden yellow to opaque dark yellow, and the aroma and taste change from a light rice aroma and slightly sweet to a distinct rice aroma and distinct sweetness to a distinct burnt and bitter taste. At a temperature of 140℃, the color of the broken rice is light yellow, the rice aroma is moderate, and the fermented kvass-like low-alcohol beverage has the highest sensory score. Under the roasting condition of 140℃, as the roasting time is extended, the color of the broken rice gradually changes from white to golden yellow, and the rice aroma gradually intensifies. When the time is 120 minutes, the sensory evaluation of the kvass-like low-alcohol beverage is the highest. Under high-temperature conditions, roasting raw rice can rapidly and effectively reduce the molecular weight of various natural macromolecules such as starch and protein, promoting the rapid synthesis of Maillard reaction and caramelization reaction products, thereby imparting color, aroma, and flavor. However, due to the increased baking temperature and extended baking time, the damage to broken rice starch and protein is aggravated, resulting in a decrease in the production of aroma and flavor substances, excessive Maillard caramelization, and an overly dark color, which affects the sensory quality of the beverage.

[0037] The broken rice-based low-alcohol kvass beverage provided by this invention has a golden-yellow appearance, is transparent and clear without sediment, has a distinct rice and hop aroma, a moderate sweetness, a uniform taste, and good acceptability.

[0038] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A preparation process for a gluten-free, low-alcohol kvass-like beverage, characterized in that, Includes the following steps: (1) Select gluten-free grains, bake, cool, and steam with water; (2) Cool, grind into a paste, add compound enzyme for enzymatic hydrolysis and saccharification, boil to inactivate the enzyme, and obtain saccharified slurry; (3) Inoculation and fermentation, to obtain the gluten-free kvass-like low-alcohol beverage; The compound enzyme is composed of α-amylase and saccharifying enzyme in a mass ratio of 1:4 to 1:

8.

2. The preparation process as described in claim 1, characterized in that, The gluten-free grains are selected from white rice, brown rice, or broken rice.

3. The preparation process as described in claim 1, characterized in that, The baking temperature is 100~200℃ and the time is 30min~180min.

4. The preparation process as described in claim 1, characterized in that, When adding water and steaming in step (1), add water at a ratio of 1g:(1~1.2)mL and steam for 30~50min.

5. The preparation process as described in claim 1, characterized in that, In step (2), water is added at a ratio of 1g:(4~6)mL when grinding.

6. The preparation process according to claim 1, characterized in that, The amount of the compound enzyme added is 2 wt.%~5 wt.%; Enzymatic hydrolysis and saccharification conditions: pH 6.0~8.0, temperature 45℃~75℃, time 10h~15h.

7. A gluten-free, low-alcohol kvass-like beverage prepared by the preparation process according to any one of claims 1 to 6.

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