High-aroma barley tea and preparation method thereof

Abstract

The invention provides high-aroma barley tea and a preparation method thereof, and belongs to the technical field of barley processing. The high-aroma barley tea provided by the invention takes baked two-ridge barley and six-ridge barley as raw materials, the materials and water are mixed and then extracted, and then the extract liquor is subjected to four-stage bag type filtration to obtain barley tea clear liquor with the turbidity less than or equal to 4.0 NTU, the obtained barley tea clear liquor has barley aroma and caramel aroma, a barley aroma marker is acetylpyrrole, the content of acetylpyrrole reaches 693.0 mu g / L, and the content of caramel in the barley tea clear liquor reaches 693.0 mu g / L; the caramel aroma marker is furanone (DMHF), and the content of the furanone (DMHF) reaches 6.23 mg / L. The preparation method of the high-aroma barley tea solves the problems that the barley tea is unstable in aroma and poor in palatability, and the prepared barley tea is rich in barley aroma, good in taste and high in nutrient content.

Description

Technical Field

[0001] The invention belongs to the technical field of barley processing, and in particular relates to a high-fragrance barley tea and a preparation method thereof. Background Art

[0002] Barley (Hordeum vulgare) is one of the oldest cultivated crops. Barley tea, made by roasting the seeds of the barley plant, is increasingly used as a drinking water alternative. Barley tea is consumed as a form of tea and its consumption is increasing throughout the year. This caffeine-free beverage is safe for people of all ages and is a healthy drink rich in bioactive ingredients. Barley tea contains phenolic substances and rich dietary fiber such as p-coumaric acid, quercetin, beta-glucan, etc., which can enhance the body's antioxidant capacity and play an important role in the normal function of the intestine.

[0003] The production process of barley tea mainly involves three parts: barley roasting, barley tea extraction and quality evaluation. Simply put, barley is roasted at high temperature to obtain roasted barley, and the barley is further crushed and sieved to obtain barley tea raw materials with uniform particle size, and finally extracted by hot water assisted by ultrasound, microwave and other processes and filtered to obtain barley tea. At present, some patents have been described in detail on the preparation method of barley tea or barley tea beverages, but the description of the barley tea extraction process is relatively simple. At the same time, due to the uncertainty of the barley roasting and extraction process, the taste and aroma of barley tea show large fluctuations, which reduces the drinkability of barley tea and produces unpleasant tastes such as sourness, bitterness and burntness.

[0004] At present, the research on barley tea in China mainly focuses on the preparation methods of barley tea raw materials and barley tea beverages. There are almost no reports on the optimization of barley tea extraction process and product evaluation standards. Summary of the invention

[0005] The invention provides a high-aroma barley tea and a preparation method thereof. Two-row and six-row barley are used as raw materials, a hot water extraction method is adopted, acetylpyrrole, furfural and pyrazine are selected as aroma quality control indicators, and the extraction rate is taken as a prerequisite for process optimization. The problems of unstable aroma and poor palatability of the barley tea are solved. The prepared barley tea has a strong wheat aroma, a good taste and high nutritional content.

[0006] In order to achieve the above object, the present invention provides a high-fragrant barley tea. The raw materials are roasted two-row barley and six-row barley. The raw materials and water are mixed and extracted. Then, the extract is subjected to 4-stage bag filtration to obtain a barley tea clear liquid with a turbidity of ≤4.0NTU. The obtained barley tea clear liquid has barley aroma and caramel aroma. The barley aroma marker is acetylpyrrole, and its content reaches 693.0μg / L. The caramel aroma marker is DMHF, and its content reaches 6.23mg / L.

[0007] In the above scheme, compared with the existing method of roasting barley and then crushing it into particles, the present embodiment omits the crushing step, which saves the investment in crushing equipment and reduces costs on the one hand; on the other hand, it reduces the difficulty of filtering and greatly reduces energy consumption.

[0008] Preferably, the total aroma marker content of the barley aroma marker and the caramel aroma marker satisfies the following formula:

[0009] Total aroma marker content (mg / L) = -0.0012*time 2 +0.215*time-2.9105, R 2 =0.9402;

[0010] The content of barley aroma markers satisfies the following formula at different extraction time stages:

[0011] Extraction 30min-70min, acetylpyrrole content (μg / L) = -0.0859*extraction time 2 +9.2003*Extraction time -154.19, R 2 =0.9431;

[0012] Extraction 70min-120min, acetylpyrrole content (μg / L) = -0.0213*extraction time 2 +3.5404*extraction time-78.04, R 2 =1.

[0013] Preferably, the mass ratio of the roasted two-row barley to the six-row barley is 5: 1-9: 1. It is understandable that if the addition ratio of the two is too low, the color of the barley tea will increase excessively, the bitterness will increase significantly, and the flavor will decrease sharply; if the ratio is too high, the flavor of the barley tea will be bland, and the extraction rate will also be greatly reduced, increasing the product cost.

[0014] Preferably, the extraction temperature is 85°C-95°C, and the extraction time is 30min-90min. It is understandable that for the set extraction temperature, if the temperature is too low, the extraction rate of roasted barley will be greatly reduced, and conversely, if the temperature is too high, the burnt and bitter taste will be obvious. At the same time, in the actual production process, due to different air pressure, heat dissipation and equipment usage, it is difficult for the water temperature in the extraction tank to reach a higher temperature.

[0015] Preferably, a food-grade foaming agent is added during the extraction of barley tea, and the added amount is 0.6 g / L-1.2 g / L. It is understandable that the addition of a foaming agent can increase the extraction rate of roasted barley and improve the taste of the extract.

[0016] Preferably, the extract is subjected to 4-stage bag filtration as follows:

[0017] First, filter through a 270-mesh vibrating screen, a 200-mesh bag filter, and a 25μ bag filter to obtain a barley tea filtrate with a turbidity of ≤30.0 NTU;

[0018] Then, the mixture was filtered through a 1μ bag filter twice to obtain a barley tea clear liquid with a turbidity of ≤4.0 NTU.

[0019] The present invention provides a method for preparing the high-fragrance barley tea according to any one of the above technical solutions, comprising the following steps:

[0020] Take a certain amount of two-row and six-row barley, add RO water at a ratio of 1:5-1:20 for extraction, the extraction temperature is 85℃-95℃, and the extraction time is 30min-90min;

[0021] After extraction, the extract was filtered through a vibrating sieve and cooled to room temperature, and then filtered through a 200-mesh bag filter, allowed to stand, filtered through a 25 μ bag filter, and centrifuged to obtain a barley tea filtrate with a turbidity of ≤30.0 NTU for preparation;

[0022] Before preparation, the barley tea filtrate is filtered through a 1μ bag filter and prepared with auxiliary materials. After mixing evenly, the prepared liquid is filtered through a 1μ bag filter to obtain a barley tea clear liquid with a turbidity of ≤4.0NTU.

[0023] Preferably, the method further comprises the steps of ultra-high temperature instantaneous sterilization and aseptic cold canning of the barley tea clear liquid to obtain a finished product of high-flavor barley tea.

[0024] The present invention provides a use of the high-fragrance barley tea according to any one of the above technical solutions in preparing a weight loss product.

[0025] The present invention provides a use of the high-fragrant barley tea according to any one of the above technical solutions in preparing a product for improving cognitive impairment, restoring long-term memory of cognitive impairment and alleviating depressive tendency.

[0026] Compared with the prior art, the advantages and positive effects of the present invention are:

[0027] The invention provides a high-fragrant barley tea. The barley tea is prepared by mixing roasted two-row barley and six-row barley, thereby solving the problems of light color and weak aroma of the barley tea. The barley crushing is abandoned and a four-stage bag filtration process is adopted to overcome the problems of high turbidity and low clarity of the barley tea. The extraction temperature and extraction time are optimized and a foaming agent is added before extraction, thereby significantly improving the extraction rate of the barley tea, increasing the content of barley aroma such as acetylpyrrole, and solving the problems of unstable aroma and poor palatability of the barley tea, so that the prepared barley tea has obvious barley aroma and slight caramel aroma, no bitter taste, good taste, and high nutritional content. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The extraction time, acetylpyrrole and DMHF fitting equations provided in Example 1 of the present invention;

[0029] Figure 2 The test results of the two-rowed barley tea provided in Example 2 of the present invention;

[0030] Figure 3 The test results of six-row barley tea provided in Example 2 of the present invention;

[0031] Figure 4 The extraction time and acetylpyrrole fitting curve diagram of two-row and six-row barley tea provided in Example 2 of the present invention;

[0032] Figure 5 The extraction rate curve of two-row and six-row barley tea with different material-water ratios provided in Example 2 of the present invention;

[0033] Figure 6 The test results of the two-rowed barley tea provided in Example 2 of the present invention;

[0034] Figure 7 The weight loss effect of barley tea provided in Example 3 of the present invention;

[0035] Figure 8 The effect of barley tea in alleviating cognitive impairment provided by Example 3 of the present invention;

[0036] Fig. 9 The stress-relieving effect of barley tea provided in Example 3 of the present invention;

[0037] Fig.10 This is the regulating effect of barley tea on blood lipids provided by Example 3 of the present invention. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Example 1

[0040] This embodiment provides a high-flavor barley tea, and the preparation method thereof is as follows:

[0041] Weighing of raw materials: Weigh roasted barley according to the weight ratio of two-row barley to six-row barley of 9:1;

[0042] Extraction: Mix the material and water in a ratio of 1:6, add 1.0g / L of foaming agent, and extract at 85℃ for 10min, 20min, 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min;

[0043] Extraction liquid filtration: After the extraction is completed, the extract is filtered through a 270-mesh vibrating screen and the filtrate is cooled to below 20°C. It is filtered again through a 200-mesh bag filter, left to stand for 30 minutes, filtered through a 25μ bag filter and centrifuged to obtain the barley tea filtrate (turbidity ≤ 30.0 NTU) and stored in a storage barrel;

[0044] Preparation: The auxiliary materials are dissolved and filtered for preparation. Before preparation, the barley tea filtrate is filtered through a 1μ bag filter again and mixed with the auxiliary material solution. After mixing evenly, the prepared liquid is filtered through a 1μ bag filter to obtain the barley tea clear liquid (turbidity ≤ 4.0 NTU);

[0045] Sterilization and canning: The filtrate is immediately sterilized by UHT (138±2℃, 30s), stored in sterile cans and cooled to room temperature, and finally filled in sterile cold cans (25±5℃) to obtain the finished product of high-flavor barley tea.

[0046] Table 1 Physical and chemical test results of some barley tea obtained in Example 1

[0047]

[0048] As shown in Table 1, the soluble fixed matter content and chromaticity value of the high-fragrance barley tea prepared in Example 1 increased significantly with the increase of extraction time (x), which indicates that under this extraction condition, the longer the extraction time, the higher the extraction rate. At the same time, acetylpyrrole and DMHF are typical flavor substances of wheat aroma and caramel aroma, respectively, and they also increase significantly with the increase of extraction time, and the wheat aroma reaches the maximum value (693.0μg / L) at 60min of extraction, and the total aroma marker content also reaches 6.92mg / L. When the extraction time is less than 30min, the soluble fixed matter content of roasted barley is far below the target value of 10%, and the caramel aroma marker DMHF of barley tea cannot be detected, and the wheat aroma marker acetylpyrrole is also less than 400μg / L. This shows that when the extraction time is less than 30min, it can neither guarantee a higher product yield to reduce costs, nor obtain a high-fragrance extract to improve product aroma and quality. When the extraction time is longer than 90 minutes, the content of soluble fixed matter in barley tea tends to be stable, but due to the long extraction time, acetylpyrrole and DMHF begin to dissipate, and the content of aroma components gradually decreases. Therefore, in order to ensure the high aroma characteristics of the product, 30 minutes to 90 minutes is selected as the optimal extraction time. Figure 1 As shown, the total aroma marker content of barley aroma marker and caramel aroma marker satisfies the following formula:

[0049] Total aroma marker content = -0.0012*time 2 +0.215*time-2.9105, R 2 =0.9402;

[0050] Therefore, in the embodiment of the present invention, acetylpyrrole and DMHF are used as barley tea quality evaluation indicators, and the above indicators all meet the requirements of the expected barley tea.

[0051] Example 2

[0052] The present embodiment provides a high-fragrant barley tea, and the preparation process is the same as that of Example 1, except that: two-row barley and six-row barley are used as raw materials, respectively, and are mixed in a material-water ratio of 1:5, 1:10 and 1:20, and the extraction temperatures are selected to be 60°C, 70°C, 80°C, 90°C, 95°C, and 98°C, respectively, and a foaming agent (1.0 g / L) is added at 95°C for different extraction times (30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min and 120 min).

[0053] Table 2 Partial physical and chemical test results of the two-row barley tea obtained in Example 2

[0054]

[0055] As shown in Table 2, the extraction rate of the two-row barley tea prepared in Example 2 increases significantly with the increase of the extraction temperature. During the production process, we found that when the temperature is further increased to above 95°C, the burnt smell of the barley tea will increase significantly, and the energy consumption will increase greatly. Therefore, 95°C is determined to be the optimal extraction temperature. At the same time, after adding the foaming agent, the extraction rate of the barley tea has been significantly improved from 6.26% to 9.62%. Based on the above results, we finally determined that 95°C is the optimal extraction temperature, and the foaming agent needs to be added to help improve the extraction rate of the barley tea.

[0056] Based on the conclusions in Table 2, we conducted extraction experiments on two-row barley and six-row barley. The experimental results showed that the relationship between the content of acetylpyrrole, a barley aroma component in the two roasted barleys, and the extraction time was not a simple linear relationship. Figure 2 As shown in the figure, the acetylpyrrole content of two-row barley reached its peak at 60 minutes, and the acetylpyrrole content was less than 1 / 2 of the peak at 120 minutes. Figure 3 As shown in the figure, before 60 minutes, the acetylpyrrole content of six-row barley was greater than that of two-row barley, and reached a peak at 40 minutes. Therefore, before 60 minutes of extraction, six-row barley provided the main aroma substances. But overall, the acetylpyrrole content in the two barley extracts was negatively correlated with the extraction time. The acetylpyrrole content of both barley teas rebounded at 60 minutes to 80 minutes. The above shows that the extraction of barley tea cannot be simply based on the extraction rate as an indicator. Only pursuing an increase in the extraction rate will lead to the loss of the aroma of barley tea.

[0057] Therefore, we recalculated the content of acetylpyrrole according to the ratio of 9:1 between two-rowed barley and six-rowed barley, as follows: Figure 4 As shown in the figure, it was found that the acetylpyrrole content in barley tea and the extraction time were in an "M" shape. When the extraction time was 60 minutes, the acetylpyrrole content in barley tea was the highest (95.26μg / L). Therefore, the extraction time of barley in different time periods (30min-70min, 70min-120min) during the extraction process was correlated with the acetylpyrrole content in the barley extract to obtain a relationship curve, as shown below:

[0058] Extraction 30min-70min, acetylpyrrole content (μg / L) = -0.0859*extraction time 2 +9.2003*Extraction time -154.19, R 2 =0.9431

[0059] Extraction 70min-120min, acetylpyrrole content (μg / L) = -0.0213*extraction time 2 +3.5404*extraction time-78.04, R 2 =1.

[0060] Further, if Figure 5 As shown in the figure, the extraction rate of the same barley raw material with different material-liquid ratios (material-water ratio 1:5, 1:10 and 1:20) is not significantly different, but the extraction rate of six-row barley is significantly higher than that of two-row barley, which proves the contribution of six-row barley to the content and color of barley tea. Figure 6 As shown in the figure, we also analyzed the flavor and color of two-row barley tea. The above results show that as the extraction time increases, the flavor of barley tea will deteriorate, specifically manifested in the weakening of wheat aroma and caramel aroma, and the increase of bitterness. At the same time, the increase of extraction time will also reduce the color of barley tea, resulting in an increase in its turbidity, affecting the quality of barley tea.

[0061] Example 3

[0062] This embodiment provides a high-flavor barley tea, and the preparation method thereof is as follows:

[0063] Weighing of raw materials: Weigh roasted barley according to the weight ratio of two-row barley to six-row barley of 9:1;

[0064] Extraction: Mix the material and water in a ratio of 1:5, add 0g / L, 0.3g / L, 0.6g / L, 1.0g / L of foaming agent, and extract at 95℃ for 60min;

[0065] Extraction liquid filtration: After the extraction is completed, the extract is filtered through a 270-mesh vibrating screen and the filtrate is cooled to below 20°C. It is filtered again through a 200-mesh bag filter, left to stand for 30 minutes, filtered through a 25μ bag filter and centrifuged to obtain the barley tea filtrate (turbidity ≤ 30.0 NTU) and stored in a storage barrel;

[0066] Preparation: The auxiliary materials are dissolved and filtered for preparation. Before preparation, the barley tea filtrate is filtered through a 1μ bag filter again and mixed with the auxiliary material solution. After mixing evenly, the prepared liquid is filtered through a 1μ bag filter to obtain the barley tea clear liquid (turbidity ≤ 4.0 NTU);

[0067] Sterilization and canning: The filtrate is immediately sterilized by UHT (138±2℃, 30s), stored in sterile cans and cooled to room temperature, and finally filled in sterile cold cans (25±5℃) to obtain the finished product of high-flavor barley tea.

[0068] Table 3 Physical and chemical test results of some barley tea obtained in Example 3

[0069]

[0070] As shown in Table 3, the extraction rate of the high-fragrance barley tea prepared in Example 3 of the present invention is significantly increased with the addition of the foaming agent, and the extraction rate is ≥ 10%. At the same time, the addition of a small amount of the foaming agent does not affect the aroma and sensory evaluation of the barley tea.

[0071] Analysis of the efficacy of barley tea

[0072] Mice were randomly divided into four groups (n = 6 per group): (1) normal group (NW) fed with a grain-based rodent laboratory diet and given drinking water; (2) normal group (NB) fed with a grain-based rodent laboratory diet and given 3 mg / mL barley tea; (3) model group (DW) fed with a high-fat diet (D12492, 60% fat energy) and given drinking water; (4) model group (DB) fed with a high-fat diet (D12492) and given 3 mg / mL barley tea. In the NB and DB groups, mice could freely drink barley tea instead of normal drinking water to satisfy thirst or relax. The NW and NB groups did not have any stress conditions, while the MW and DB groups were subjected to chronic mild stress (CMS). Two cognitive behavioral tests were performed during the intervention period (described below). After 220 days, all mice were fasted for 12 hours and anesthetized with ether, and then killed by cervical dislocation. Serum, tissue, and colon content samples were collected for testing in a timely manner.

[0073] In this study, we used a long-term (220 days) high-fat diet and chronic unpredictable mild stress to induce a MCI mouse model. Using this model, we evaluated the effects of replacing water with barley tea on cognitive function and lipid metabolism in healthy mice (NW) and cognitively impaired mice (DW). Figure 7 It can be seen that long-term intake of barley tea can significantly reduce the weight of healthy mice and has a good weight loss effect. Fig.10 It can be seen that long-term intake of barley tea also has a good regulating effect on the blood lipids of mice. Barley tea has restored the blood lipid metabolism disorder caused by modeling to a certain extent. Figure 8-9 It can be seen that long-term intake of barley tea can restore the long-term memory of cognitively impaired mice and alleviate their tendency to depression. At the same time, for cognitively impaired mice, consuming barley tea can also improve their nesting ability, which also shows that barley tea can improve the executive ability and mood of cognitively impaired mice, relieve their stress, and has the potential to improve brain lesions in mice.

Claims

1. A high-flavor barley tea, characterized in that: Roasted two-row barley and six-row barley are used as raw materials, the raw materials and water are mixed and extracted, and then the extract is subjected to 4-stage bag filtration to obtain a barley tea clear liquid with a turbidity of ≤4.0NTU. The obtained barley tea clear liquid has barley aroma and caramel aroma. The barley aroma marker is acetylpyrrole, and its content reaches 693.0μg / L. The caramel aroma marker is DMHF, and its content reaches 6.23mg / L.

2. The high-flavor barley tea according to claim 1, characterized in that The total aroma marker content of the barley aroma marker and the caramel aroma marker satisfies the following formula: Total aroma marker content (mg / L) = -0.0012*time 2 +0.215*time-2.9105, R 2 =0.9402; The content of barley aroma markers satisfies the following formula at different extraction time stages: Extraction 30min-70min, acetylpyrrole content (μg / L) = -0.0859*extraction time 2 +9.2003*Extraction time -154.19, R 2 =0.9431; Extraction 70min-120min, acetylpyrrole content (μg / L) = -0.0213*extraction time 2 +3.5404*extraction time-78.04, R 2 =1.

3. The high-flavor barley tea according to claim 1 or 2, characterized in that The mass ratio of the added roasted two-row barley to the six-row barley is 5:1-9:

1.

4. The high-flavor barley tea according to claim 1 or 2, characterized in that The extraction temperature is 85°C-95°C, and the extraction time is 30min-90min.

5. The high-flavor barley tea according to claim 1 or 2, characterized in that When extracting barley tea, a food-grade foaming agent is added in an amount of 0.6 g / L-1.2 g / L.

6. The high-flavor barley tea according to claim 1 or 2, characterized in that The extract is subjected to 4-stage bag filtration as follows: First, filter through a 270-mesh vibrating screen, a 200-mesh bag filter, and a 25μ bag filter to obtain a barley tea filtrate with a turbidity of ≤30.0 NTU; Then, the mixture was filtered through a 1μ bag filter twice to obtain a barley tea clear liquid with a turbidity of ≤4.0 NTU.

7. The method for preparing the highly fragrant barley tea according to any one of claims 1 to 6, characterized in that: The following steps are involved: Take a certain amount of two-row and six-row barley, add RO water at a ratio of 1:5-1:20 for extraction, the extraction temperature is 85℃-95℃, and the extraction time is 30min-90min; After extraction, the extract was filtered through a vibrating sieve and cooled to room temperature, and then filtered through a 200-mesh bag filter, allowed to stand, filtered through a 25 μ bag filter, and centrifuged to obtain a barley tea filtrate with a turbidity of ≤30.0 NTU for preparation; Before preparation, the barley tea filtrate is filtered through a 1μ bag filter and prepared with auxiliary materials. After mixing evenly, the prepared liquid is filtered through a 1μ bag filter to obtain a barley tea clear liquid with a turbidity of ≤4.0NTU.

8. The preparation method according to claim 7, characterized in that: The method also includes the steps of ultra-high temperature instant sterilization and aseptic cold canning of the barley tea clear liquid to obtain the finished product of high-fragrant barley tea.

9. Use of the high-fragrant barley tea according to any one of claims 1 to 6 in preparing a weight loss product.

10. Use of the highly fragrant barley tea according to any one of claims 1 to 6 in the preparation of products for improving cognitive impairment, restoring long-term memory of cognitive impairment, and alleviating depressive tendencies.

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