Preparation method of black tea cookies

Abstract

The invention discloses a preparation method of black tea cookies, and relates to the technical field of cookie preparation, the preparation method comprises the following steps: A, raw material selection: black tea cookies consist of black tea powder, Ziziphus jujube powder, brown sugar, butter, milk and low-gluten flour; b, preparation of black tea powder: putting a proper amount of black tea into a high-speed crusher for crushing, sieving with a 80-mesh sieve, and loading into a sealing bag to obtain the black tea powder for later use; the polyphenol content of the black tea cookies can reach 0.435%, the bulk density is 0.59 g / cm < 3 >, the fat content is 27.58%, and the polyphenol content of the black tea cookies is nearly ten times that of milk-flavored cookies, so that the shelf life of the tea-containing cookies can be obviously prolonged, the hardness and the chewiness of the black tea cookies are obviously higher than those of the milk-flavored cookies, the brittleness of the black tea cookies is also obviously higher than that of the milk-flavored cookies, and the black tea cookies are suitable for being eaten by people. The reason may be that the black tea powder reduces the water absorption and oil absorption of the dough, the internal tissue structure gap is increased, the dough becomes loose and hard in texture, and the black tea cookies may have better satiety than common cookies.

Description

Technical Field

[0001] The present invention relates to the technical field of cookie preparation, and specifically to a preparation method of black tea cookies. Background Art

[0002] Cookies are a type of biscuit with a crispy texture and rich aroma, and are popular baked foods among consumers. Cookie biscuits are generally made from low-gluten flour, butter, sugar, eggs, etc. through processes such as dough modulation, shaping, and baking. Traditional cookie biscuits contain a large amount of butter and sugar, and are high-oil and high-sugar foods. Currently, many studies have shown that the usage of white sugar in cookie biscuits is above 30%. The addition of sugar not only affects the taste and tissue structure of cookie biscuits, but also easily causes various diseases such as obesity, hyperlipidemia, type 2 diabetes, and cardiovascular and cerebrovascular diseases.

[0003] Compared with traditional cookie biscuits, tea-containing cookie biscuits contain rich nutritional and functional components, have good antibacterial and antioxidant properties, and can extend the shelf life of biscuits. Studies have shown that green tea cookie biscuits and matcha cookie biscuits have better crispness; the addition of green tea or matcha can improve the taste of biscuits, but the use and research of black tea powder in tea-containing biscuits are relatively few. Ankang black tea, made from fresh tea leaves in summer and autumn, has characteristics such as green color and selenium enrichment. In this study, Ankang black tea, Shaanbei dog head jujube, and brown sugar were used as the main raw materials. Through single-factor experiments combined with orthogonal experiments, the sensory quality and physicochemical properties of black tea cookie biscuits were analyzed and studied, and the formula of black tea cookie biscuits was optimized to further provide ideas for the development of Ankang black tea foods. Therefore, we propose a preparation method of black tea cookie biscuits. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of black tea cookie biscuits to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: A preparation method of black tea cookie biscuits, the preparation method includes the following steps:

[0006] A. Raw material selection: The black tea cookie is composed of black tea powder, dog head jujube powder, brown sugar, butter, milk, and low-gluten flour. Among them, 3 g of black tea powder, 20 g of dog head jujube powder, 10 g of brown sugar, 55 g of butter, 60 g of milk, and 100 g of low-gluten flour are weighed respectively by weight;

[0007] B. Preparation of black tea powder: Put an appropriate amount of black tea into a high-speed pulverizer for pulverization, pass through an 80-mesh sieve, and put it into a sealed bag to obtain black tea powder for standby;

[0008] C. Preparation of dog head jujube powder: Cut the pitted dog head jujubes into thin strips, place them in an oven for baking. After completely cooling, put the dog head jujubes into a high-speed crusher and crush them for 5 - 10 s. Sieve the crushed dog head jujube powder through a 40-mesh sieve and put it into a sealed bag for later use;

[0009] D. Dough modulation: Whip the softened butter in advance with a whisk. Then dissolve brown sugar in an appropriate amount of milk to obtain a sugar-milk mixture. Subsequently, pour the sugar-milk mixture into the whipped butter and continue to whip until the shape of the butter becomes feathery and the volume expands significantly. Finally, add the dog head jujube powder and black tea powder to the butter, whip it again until it becomes feathery, and then add the sifted cake flour;

[0010] E. Dough shaping: Assemble a piping bag, put the dough into the front end of the piping bag, and squeeze the dough into round cookie wet blanks;

[0011] F. Baking: Put the cookie wet blanks into the oven and bake for 20 min. After the time is up, take out the cookies and let them cool for 10 min to release moisture. At the same time, set the temperature of the oven to 150 °C for the bottom heat and 170 °C for the top heat;

[0012] G. Cooling and packaging: After baking, let the cookie biscuits cool to room temperature to continue evaporating moisture. After the cookies gradually harden, promptly put them into a sealed bag and attach the corresponding labels.

[0013] Preferably, in step A.

[0014] Preferably, in step B, through the high-speed relative movement between the movable disk and the fixed disk of the high-speed crusher, the black tea is crushed by the comprehensive action of impact, shear, friction between the movable disk and the fixed disk and the impact between the black teas themselves. The spindle speed of the high-speed crusher is 4200 revolutions per minute.

[0015] Preferably, in step C, put the thin strip-shaped dog head jujubes on the baking tray in the oven for baking. The bottom heat in the oven is 80 °C and the top heat is 90 °C. Weigh them every 20 min and dry them in the sun for 10 min before re-baking until the difference in weight between the two times is less than 0.5% of the weight before the initial baking.

[0016] Preferably, in step D, when modulating the dough, stir the raw materials from the edge of the mixing bowl to the center of the mixing bowl. Stop kneading immediately when there is no flour at the bottom of the mixing bowl to prevent over-kneading and affecting the crispness of the cookie biscuits.

[0017] Preferably, when sieving the cake flour in step D, it needs to be sieved twice. The first sieving is through a 60-mesh sieve and the second sieving is through a 40-mesh sieve to ensure the fineness and uniformity of the cake flour.

[0018] Preferably, before putting the cookie wet blanks into the oven in step F, set the oven to have a bottom heat of 160 °C and a top heat of 180 °C, and preheat the oven for 20 minutes in advance.

[0019] Preferably, before putting the dough into the front end of the piping bag in step E, lay a layer of special baking tin foil on the baking tray. The tin foil is made of aluminum foil paper, and the matte side of the tin foil should be in contact with the dough, while the shiny side is exposed outside. The thickness of the tin foil is 0.025 mm.

[0020] Preferably, the dog head jujube powder in step C should have a natural color, showing a brownish-yellow or dark red color, and have a strong jujube fragrance, without any peculiar smell or strange taste. Moreover, the dog head jujube powder should be large in size, thick in flesh, small in core, and sweet in taste.

[0021] Preferably, after the initially baked cookies are well-shaped in step F, put them into the oven again for 25 minutes of re-baking.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The sensory quality of the black tea cookies obtained by the present invention shows that the shape is complete and uniform, the cross-section is delicate, there are small and dense pores, the color is bright and uniform, the surface presents a yellowish-brown color, the taste is crispy, the aroma and taste of black tea are more prominent, the overall taste and fragrance are coordinated, its brittleness and looseness are better than those of ordinary cookies, the polyphenol content is nearly ten times that of ordinary cookies, and it has good quality.

[0024] 2. The polyphenol content of this black tea cookie of the present invention can reach 0.435%, the looseness is 0.59 g / cm3, and the fat content is 27.58%. The polyphenol content of the black tea cookie is nearly ten times that of the milk-flavored cookie. Therefore, the shelf life of the tea-containing cookie can be significantly extended. The hardness and chewiness of the black tea cookie are extremely significantly higher than those of the milk-flavored cookie, and its crispness is also significantly higher than that of the milk-flavored cookie. The reason may be that the black tea powder reduces the water absorption and oil absorption of the dough, increases the voids in its internal tissue structure, becomes more crispy and loose, and the texture becomes harder. The black tea cookie may have a better satiety than ordinary cookies. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the process flow chart of the present invention;

[0026] Figure 2 is the influence diagram of the addition amount of black tea powder on the total sensory score of black tea cookies of the present invention;

[0027] Figure 3 is the influence diagram of the addition amount of dog head jujube powder on the total sensory score of black tea cookies of the present invention;

[0028] Figure 4 is the influence diagram of the addition amount of brown sugar on the total sensory score of black tea cookies of the present invention. Detailed implementation manners

[0029] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without making creative efforts belong to the scope of protection of the present invention.

[0030] Embodiment 1

[0031] Please refer to Figures 1-4 , the present invention provides a technical solution: a preparation method of black tea cookies. The present invention makes corresponding improvements to the technical problems mentioned in the background technology. The preparation method includes the following steps:

[0032] A. Raw material selection: The black tea cookies are composed of black tea powder, dog head jujube powder, brown sugar, butter, milk and low-gluten flour. Weigh 3 g of black tea powder, 20 g of dog head jujube powder, 10 g of brown sugar, 55 g of butter, 60 g of milk and 100 g of low-gluten flour respectively by weight;

[0033] B. Preparation of black tea powder: Put an appropriate amount of black tea into a high-speed grinder for grinding, and pass through an 80-mesh sieve, then put it into a sealed bag to obtain black tea powder for standby. The high-speed grinder makes the black tea be ground through the comprehensive effects of impact, shearing, friction between the moving disk and the fixed disk and the impact between the black teas through the high-speed relative movement between the moving disk and the fixed disk. Among them, the spindle speed of the high-speed grinder is 4200 revolutions per minute;

[0034] C. Preparation of dog head jujube powder: Cut the pitted dog head jujubes into thin strips, place them in an oven for baking. After completely cooling, put the dog head jujubes into a high-speed grinder for grinding for 5 - 10 s. The ground dog head jujube powder passes through a 40-mesh sieve and is put into a sealed bag for standby. Put the thin strip-shaped dog head jujubes on the baking tray in the oven for baking. Among them, the bottom fire in the oven is 80°C, the surface fire is 90°C, and take out and weigh every 20 min, and then dry in the sun for 10 min and then re-bake until the difference in weight between the two times is less than 0.5% of the weight before the initial baking. The dog head jujube powder should have a natural color, showing brownish yellow or dark red, and have a strong red date fragrance, without peculiar smell or strange smell, and the dog head jujube powder should be large in size, thick in flesh, small in core and sweet in taste;

[0035] D. Dough modulation: Whip the butter softened in advance with a whisk. Then dissolve brown sugar in an appropriate amount of milk to obtain a sugar-milk mixture. Subsequently, pour the sugar-milk mixture into the whipped butter and continue to whip until the shape of the butter becomes feathery and its volume expands significantly. Finally, add the powder of dog head jujube and black tea powder to the butter, whip it again until it becomes feathery, and then add the sifted cake flour. When modulating the dough, turn the raw materials from the edge of the basin to the center of the basin, and immediately stop kneading when there is no flour at the bottom of the basin to prevent over-kneading from affecting the crispness of the cookies. The cake flour needs to be sifted twice. One sifting is through a 60-mesh sieve, and the second sifting is through a 40-mesh sieve to ensure the fineness and uniformity of the cake flour;

[0036] E. Dough shaping: Assemble a piping bag and a piping tip with a diameter of 0.7 cm. Put the dough at the front end of the piping bag, and squeeze the dough into round cookie wet blanks with a diameter of about 3 cm. Before putting the dough at the front end of the piping bag, lay a layer of special baking tin foil on the baking tray. The tin foil is made of aluminum foil, and the matte side of the tin foil should be in contact with the dough, while the shiny side is exposed outside. The thickness of the tin foil is 0.025 mm;

[0037] F. Baking: Put the cookie wet blanks into the oven and bake for 20 minutes. After the time is up, take out the cookies and let them cool for 10 minutes to release moisture. At the same time, set the temperature of the oven to 150 °C for the bottom heat and 170 °C for the top heat. Before putting the cookie wet blanks into the oven, set the oven to 160 °C for the bottom heat and 180 °C for the top heat, and preheat the oven for 20 minutes in advance. After the initially baked cookies are well-shaped, put them into the oven again for 25 minutes of re-baking;

[0038] G. Cooling and packaging: After baking, let the cookies cool to room temperature to continue evaporating moisture. When the cookies gradually harden, promptly put them into a sealed bag and attach the corresponding label.

[0039] Example 2

[0040] Please refer to Figures 1-4 , the present invention provides a technical solution: a preparation method of black tea cookies,

[0041] Single-factor experimental design:

[0042] (1) Influence of the addition amount of black tea powder on the sensory quality of cookies

[0043] During the single-factor experiment, control the single variable. The addition amounts of black tea powder in the single-factor experiment are 6 gradients of "0 g, 3 g, 6 g, 9 g, 12 g, 15 g" respectively. 100 g of cake flour, 55 g of butter, 60 g of milk, and 15 g of both the powder of dog head jujube and brown sugar are added. According to the production process and key points of the black tea cookies in Example 1 above, study and analyze the influence of the addition amount of black tea powder on the sensory quality of cookies.

[0044] (2) Influence of the addition amount of jujube powder on the sensory quality of cookies

[0045] In the single-factor experiment, the addition amounts of jujube powder were 6 gradients of "0g, 5g, 10g, 15g, 20g, 25g". With 100g of cake flour, 55g of butter, 60g of milk, 15g of brown sugar, and 6g of black tea powder, according to the production process and key points of black tea cookies in Example 1 above, the influence of the addition amount of jujube powder on the sensory quality of cookies was studied and analyzed.

[0046] (3) Influence of the addition amount of brown sugar on the sensory quality of cookies

[0047] In the single-factor experiment, the addition amounts of brown sugar were 6 gradients of "0g, 5g, 10g, 15g, 20g, 25g". With 100g of cake flour, 55g of butter, 60g of milk, 15g of jujube powder, and 6g of black tea powder, according to the production process and key points of black tea cookies in Example 1 above, the influence of the addition amount of brown sugar on the sensory quality of cookies was studied and analyzed.

[0048] Orthogonal experiment design:

[0049] According to the results of the single-factor experiment, the factors and levels of the orthogonal experiment were determined, and an orthogonal experiment was designed in combination with the L9(3 4 ) orthogonal table.

[0050] Sensory evaluation:

[0051] According to the sensory evaluation standard for making black tea cookies in GB / T 20980-2021 General Rules for Biscuit Quality, 10 sensory evaluation personnel (without special taste preferences) scored the five sensory evaluation items of appearance shape, tissue structure, color and luster, taste and smell according to the standard, using a 100-point scoring system. The specific scoring criteria are shown in Table 1.

[0052] Table 1 Sensory evaluation standard for black tea cookies

[0053]

[0054] Verification experiment and physical and chemical determination: Make black tea cookie samples according to the optimal formula obtained from the orthogonal experiment, and conduct physical and chemical index determination and comparative analysis with commercially available milk-flavored butter cookies.

[0055] The moisture content was determined by the direct drying method in GB / T 5009.3-2016 Determination of Moisture in Foods. The alkalinity was determined according to the alkalinity test method in GB / T 20980-2021 General Rules for the Quality of Biscuits. The fat content was determined by the Soxhlet extraction method in GB / T 5009.6-2016 Determination of Fat in Foods. The texture was measured using a TA.TOUCH-5 texture analyzer. The biscuits were cut into thin slices with a mass of 0.5 g ± 0.02 g, and a probe was used for the downward pressure experiment. The TA program was designed as follows: the test mode was downward pressure; the pre-test, in-test, and post-test rates were 2, 1, and 2 mm / s respectively; the target mode was a displacement of 2 mm; the trigger force was 5 g, and the return distance was 8 mm. Each sample was measured in parallel 3 times, and the hardness, brittleness, and chewiness data were recorded. The bulk density was determined according to the arbitration method in GB / T 20980-2021 General Rules for the Quality of Biscuits. The mass of a single cookie was recorded as M, the radius and height of the cookie were measured, and the volume of the cookie was calculated using the cylinder formula V = hπR 2 to obtain the volume of the cookie. Finally, using the calculation method in the national standard P = M / V, the P value is the bulk density of the cookie. The polyphenol content was determined according to GB / T8313-2018 Detection Methods for the Contents of Tea Polyphenols and Catechins in Tea, combined with the experimental process of Liao Sulan to measure the tea polyphenol content in tea and cookies. 0.2 g of the ground cookie sample was taken, extracted in a water bath at 70 °C with 70% methanol solution, centrifuged at high speed, and the supernatant was taken. The obtained sample solution and gallic acid solution were made up to the test solution and detected at λ = 765 nm. The polyphenol content was determined using gallic acid as the calibration standard.

[0056] Data processing: Excel 2016 was used to organize the data, and IBM SPSS Statistics 19 software was used for the analysis of significant differences.

[0057] Results and Analysis

[0058] Results of single-factor experiments:

[0059] Effect of black tea powder addition amount on the sensory quality of cookies;

[0060] From the average scores in Table 2 combined with the significance analysis, it can be seen that the addition amount of black tea powder has little effect on the appearance shape of black tea cookies. The appearance shape quality of black tea cookies with the addition amount of black tea powder between 3 - 9g is significantly better than that of black tea cookies without adding black tea powder or with an addition amount exceeding 12g. When the addition amount of black tea powder is 6g, the tissue structure of black tea cookies reaches the optimal state, which is significant compared to black tea cookies of other gradients. The addition amount of black tea powder has the most significant impact on color and taste. Among the 6 addition amount gradients, there are 5 groups of significance. When the addition amount of black tea powder is between 3 - 6g, the color quality of black tea cookies reaches the optimal state and is significant compared to the color of other black tea cookies. When the addition amount of black tea powder is 3g, the taste and aroma quality of black tea cookies reach the optimal state, and there are significant differences in color, taste, and aroma quality compared to other black tea cookies.

[0061] Table 2 Influence of the addition amount of black tea powder on the sensory quality of cookies

[0062]

[0063]

[0064] Note: Different lowercase letters indicate significant differences in the same column. The meaning of lowercase letters in the following tables is the same as this. (P < 0.05)

[0065] Combined with Appendix Figure 2 It can be seen that as the addition amount of black tea powder gradually increases, the total sensory score of black tea cookies shows an upward trend. When the addition amount of black tea powder is 3g, the score of black tea cookies reaches the highest value of 90.83 points. After that, as the tea content gradually increases, the total sensory score of black tea cookies shows a gradually decreasing trend. When the addition amount of black tea exceeds 12g, the total sensory score drops sharply. Combining the significance analysis, it is very likely that the sharp drop in score is caused by the dark color and bitter taste of black tea cookies due to excessive tea content. Therefore, the selected levels of the black tea powder factor in the orthogonal experiment are 3g, 6g, and 9g.

[0066] Influence of the addition amount of dog head jujube powder on the sensory quality of cookies;

[0067] Table 3 Influence of the addition amount of dog head jujube powder on the sensory quality of black tea cookies

[0068]

[0069] From the average scores in Table 3 combined with the significance analysis, it can be seen that the addition amount of Gou Tou jujube powder also has no significant effect on the appearance shape of black tea cookies. The tissue structure of black tea cookies with the addition of Gou Tou jujube powder is significantly better than that of black tea cookies without the addition of Gou Tou jujube powder. When the addition amount of Gou Tou jujube powder is 10 - 20 g, the color of black tea cookies significantly reaches a better level, and the addition amount of Gou Tou jujube powder has a significant effect on the color of black tea cookies. The addition of Gou Tou jujube powder has a relatively significant effect on the taste and aroma of black tea cookies. When the addition amount of Gou Tou jujube powder is 15 g, both the taste and aroma reach the highest value, which is more significant compared to the other groups.

[0070] From the appendix Figure 3 it can be seen that as the addition amount of Gou Tou jujube powder gradually increases, the total sensory score of black tea cookies shows an upward trend. When the addition amount is 15 g, the total sensory score of black tea cookies reaches the peak value of 88.75 points. After that, as the addition amount of Gou Tou jujube powder increases, the total sensory score of black tea cookies begins to decline. Therefore, the addition amounts of 10 g, 15 g, and 20 g of Gou Tou jujube powder are selected as the three levels of the orthogonal experiment.

[0071] The influence of the addition amount of brown sugar on the sensory quality of cookies;

[0072] From the average item scores in Table 4 combined with the significance analysis, it can be seen that the addition amount of brown sugar has little effect on the tissue structure and color of black tea cookies. When the addition amounts of brown sugar are 10 g and 15 g, the tissue structure and color quality of black tea cookies reach the best and are significant compared to other gradients. When the addition amount of brown sugar is 10 g, the taste and aroma quality of black tea cookies reach the best and are significant compared to other gradients. The addition amount of brown sugar has the greatest influence on the appearance quality of black tea cookies. There are 5 groups with significance among the 6 addition amount gradients, and when the addition amount of brown sugar is 10 g, the average score is the highest and is significant compared to other addition amounts.

[0073] Table 4 Influence of the addition amount of brown sugar on the sensory quality of black tea cookies

[0074]

[0075] From the appendix Figure 4 it can be seen that as the addition amount of brown sugar increases, the sensory score of black tea cookies also gradually increases. Until the addition amount reaches 10 g, the sensory score reaches the peak value of 88.55 points. When the addition amount of brown sugar reaches 15 g and after, due to the overly sweet taste, the sensory score drops sharply. Therefore, the addition amounts of 5 g, 10 g, and 15 g of brown sugar are selected as the three levels of the orthogonal experiment.

[0076] Results of the orthogonal experiment

[0077] Orthogonal experiment design;

[0078] An orthogonal experiment was designed according to the 3 levels of the addition amounts of black tea powder, Chinese jujube powder and brown sugar obtained from the results of single-factor experiments. The factors and levels of the orthogonal experiment are shown in Table 5.

[0079] Table 5 Factors and levels of the orthogonal experiment for black tea cookies

[0080]

[0081] Orthogonal experiment for black tea cookies

[0082] The sensory evaluation and orthogonal results of black tea cookies are shown in Table 6. When sensory evaluation is used as the basis for evaluating black tea cookies, the order of influence of the three factors on the score is A > B > C. The optimal formula for black tea cookies is when the addition amount of black tea powder is 3 g, the addition amount of Chinese jujube powder is 20 g, and the addition amount of brown sugar is 10 g.

[0083] Table 6 Sensory evaluation and orthogonal results of black tea cookies

[0084]

[0085] Continued table

[0086]

[0087] Analysis of variance of the orthogonal experiment in Table 7 shows that the addition amount of black tea powder has a significant effect on the sensory properties of the nine groups of products in the orthogonal experiment, while the addition amounts of Chinese jujube powder and brown sugar have no significant effect on the sensory properties of the nine groups of products in the orthogonal experiment.

[0088] Table 7 Orthogonal variance analysis of sensory scores

[0089]

[0090] Note: * indicates that the influence of this factor has a significant difference (P < 0.05)

[0091] Verification experiment

[0092] The moisture content of the black tea cookies prepared according to the optimal formula for black tea cookies is 2.8%. Its polyphenol content, fat content, bulk density (the smaller the bulk density of the cookie, the crispier it is), hardness, crispness, chewiness and alkalinity are shown in Table 8. The polyphenol content of the black tea cookies is 0.435%, the fat content is 27.58%, and the bulk density is 0.59 g / cm 3 , the hardness is 6466.88 gf, the chewiness is 434.21 gf, the polyphenol content of the butter milk-flavored cookies is 0.047%, the fat content is 23.45%, and the bulk density is 0.86 g / cm 3, with a hardness of 2478.60 gf and chewiness of 135.04 gf, there are extremely significant differences between the above properties of black tea cookies and milk-flavored butter cookies. The crispness of black tea cookies is 5030.8 gf, and that of butter milk cookies is 2309.75 gf, showing significant differences between the two. The alkalinity of black tea cookies is 0.066 g / 100 g (calculated as sodium carbonate), and that of butter milk cookies is 0.04 g / 100 g, with no significant difference between the two.

[0093] Table 8 Physical and Chemical Results of Black Tea Cookies and Milk-flavored Cookies

[0094]

[0095]

[0096] Note: “**” indicates extremely significant correlation at the 0.01 level; “*” indicates significant correlation at the 0.05 level.

[0097] Conclusions and Discussions

[0098] In this invention, single-factor experiments combined with orthogonal experiments were adopted, and through verification, the formula of black tea cookies was determined as 100 g of low-gluten flour, 60 g of milk, 55 g of butter, 20 g of Gou Tou Zao powder, 3 g of black tea powder, and 10 g of brown sugar; the baking parameters were: surface temperature 180 °C, bottom temperature 160 °C, taken out after baking for 20 min, left to stand at room temperature for 10 min; then subjected to secondary baking (bottom temperature 150 °C, surface temperature 170 °C), taken out after 25 min, and cooled to room temperature to obtain the product.

[0099] Tea can affect the brightness of tea-containing cookies, and there is a correlation between the tea addition amount and color change. In the experiment of optimizing the process of black tea cookies, it was found through sensory evaluation that adding black tea powder would affect its color. How to reduce the influence of tea on the color of cookies has become a difficult problem for tea-containing cookies. Research shows that the color of tea is negatively correlated with baking time and temperature. Measures such as reducing baking temperature and shortening baking time can be taken to optimize the quality of tea-containing cookies. This experiment can start from the thickness of the cookies and the water addition amount during dough preparation, thereby reducing baking temperature and shortening baking time, and then improving the color of tea-containing cookies.

[0100] Through the physical and chemical determination of black tea cookies, it can be known that the polyphenol content of this type of black tea cookies can reach 0.435%, and the bulk density is 0.59 g / cm 3, with a fat content of 27.58%, the polyphenol content of black tea cookies is nearly ten times that of milk-flavored cookies. Therefore, the shelf life of tea-containing cookies can be significantly extended. The hardness and chewiness of black tea cookies are extremely significantly higher than those of milk-flavored cookies, and their crispness is also significantly higher than that of milk-flavored cookies. The reason may be that black tea powder reduces the water absorption and oil absorption of the dough, increases the voids in its internal tissue structure, becomes more crispy and loose, and the texture becomes harder. Black tea cookies may have a better sense of satiety than ordinary cookies.

[0101] The sensory quality of the black tea cookies obtained in this study is manifested as a complete and uniform appearance, a delicate cross-section, small and dense pores, a bright and uniform color, a yellowish-brown color on the surface, a crispy taste, a more prominent aroma and taste of black tea, a coordinated overall taste and fragrance, better brittleness and looseness than ordinary cookies, a polyphenol content nearly ten times that of ordinary cookies, and good quality.

[0102] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0103] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing black tea cookies, characterized in that: The preparation method comprises the following steps: A. Raw material selection: The black tea cookies are composed of black tea powder, dog head jujube powder, brown sugar, butter, milk and cake flour. By weight, 3 g of black tea powder, 20 g of dog head jujube powder, 10 g of brown sugar, 55 g of butter, 60 g of milk and 100 g of cake flour are weighed respectively; B. Preparation of black tea powder: Put an appropriate amount of black tea into a high-speed grinder for pulverization, and pass through an 80-mesh sieve, then put it into a sealed bag to obtain black tea powder for standby; C. Preparation of dog head jujube powder: Cut the pitted dog head jujubes into thin strips, place them in an oven for baking. After completely cooling, put the dog head jujubes into a high-speed grinder for pulverization for 5 - 10 s. The pulverized dog head jujube powder passes through a 40-mesh sieve and is put into a sealed bag for standby; D. Dough modulation: Whip the butter softened in advance with a whisk. Then dissolve the brown sugar in an appropriate amount of milk to obtain a sugar-milk mixture. Subsequently, pour the sugar-milk mixture into the whipped butter and continue to whip until the shape of the butter becomes feathery and the volume expands significantly. Finally, add the dog head jujube powder and black tea powder to the butter, whip again until it becomes feathery and then add the sifted cake flour; E. Dough shaping: Assemble a piping bag, put the dough at the front end of the piping bag, and squeeze the dough into round cookie wet blanks; F. Baking: Put the cookie wet blanks into an oven for baking for 20 min. After the time is up, take out the cookies and let them cool for 10 min to release moisture. At the same time, set the bottom heat of the oven to 150 °C and the top heat to 170 °C; G. Cooling and packaging: After baking, let the cookies cool to room temperature to allow the moisture to continue to evaporate. When the cookies gradually harden, promptly put them into a sealed bag and attach corresponding labels.

2. The preparation method of the black tea cookie according to claim 1, characterized in that: In step E, a piping tip with a diameter of 0.7 cm is assembled for the piping bag, and the diameter of the round cookie wet blanks extruded is 3 cm.

3. The preparation method of the black tea cookie according to claim 1, wherein: In step B, through the high-speed relative movement between the movable disk and the fixed disk of the high-speed grinder, the black tea is pulverized by the comprehensive action of impact, shearing, friction between the movable disk and the fixed disk and the impact between the black teas themselves. The spindle speed of the high-speed grinder is 4,200 revolutions per minute.

4. The preparation method of the black tea cookies according to claim 1, characterized in that: In step C, the thin strip-shaped dog head jujubes are put on a baking tray in the oven for baking. The bottom heat in the oven is 80 °C and the top heat is 90 °C. Weigh them every 20 min and re-bake them after drying for 10 min until the difference in weight between the two times is less than 0.5% of the weight before the initial baking.

5. The preparation method of the black tea cookies according to claim 1, characterized in that: In step D, when modulating the dough, turn and mix the raw materials from the edge of the mixing bowl towards the center of the mixing bowl. Immediately stop kneading when there is no flour at the bottom of the mixing bowl to prevent over-kneading from affecting the crispness of the cookies.

6. The preparation method of the black tea cookies according to claim 1, characterized in that: In step D, the cake flour needs to be sifted twice during sieving. The first sieving is through a 60-mesh sieve and the second sieving is through a 40-mesh sieve to ensure the fineness and uniformity of the cake flour.

7. The preparation method of the black tea cookie according to claim 1, wherein: Before putting the cookie wet blanks into the oven in step F, set the bottom heat of the oven to 160 °C and the top heat to 180 °C, and preheat the oven for 20 min in advance.

8. The preparation method of the black tea cookie according to claim 1, characterized in that: Before putting the dough at the front end of the piping bag in step E, a layer of special baking tin foil needs to be laid on the baking tray. The tin foil is made of aluminum foil, and the matte side of the tin foil should be in contact with the dough, with the shiny side facing out. The thickness of the tin foil is 0.025 mm.

9. The preparation method of the black tea cookies according to claim 1, characterized in that: In step C, the Gou Tou jujube powder should have a natural color, presenting as brownish yellow or dark red, and have a strong jujube fragrance, without any peculiar smell or strange taste. Moreover, the Gou Tou jujube powder should be large in size, thick in flesh, small in pit, and sweet in taste.

10. The preparation method of the black tea cookie according to claim 1, characterized in that: After the initially baked cookies are well-shaped in step F, they are put into the oven again for 25 minutes of re-baking.

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