Fruit coffee and preparation method thereof

Abstract

The invention relates to the technical field of coffee beverage preparation, and particularly discloses fruit coffee and a preparation method thereof.The fruit coffee comprises the following raw materials: compound coffee liquid, fresh milk, a flavor regulator, dietary fibers and a stabilizer; the preparation method of the fruit coffee comprises the following steps: mixing the compound coffee liquid with the fresh milk, adding the flavor regulator, the dietary fibers and the stabilizer, homogenizing at high pressure, and carrying out high-temperature instantaneous sterilization and sterile filling to obtain the fruit coffee. The prepared fruit coffee is mellow and fine in taste, unique in flavor, good in stability, not prone to layering and deterioration during storage and transportation, rich in dietary fiber and capable of promoting digestion and enhancing satiety, and has the advantages of refreshing and not prone to causing insomnia.

Description

Technical Field

[0001] This application relates to the technical field of coffee beverage preparation. More specifically, it relates to a fruit coffee and its preparation method. Background Art

[0002] As a globally widely consumed beverage, coffee has various effects such as refreshing the mind and promoting metabolism, and is deeply loved by consumers. Traditional coffee is mainly made by grinding coffee beans and brewing them. It has a mellow taste and rich aroma, but has problems such as a relatively single taste and being relatively bitter. In addition, coffee contains a relatively high content of caffeine, and some consumers are prone to discomfort symptoms such as insomnia after drinking it, making it difficult to meet the increasingly diverse taste needs of consumers.

[0003] In recent years, with the enhancement of consumers' health awareness, the requirements for the health of beverages have also become higher and higher. Fruits are rich in natural sugars, vitamins, minerals, and unique fruit aromas, which can provide a fresh taste and rich nutrition for coffee. Some products that simply mix fruit juice and coffee have emerged on the market, but there are many problems: on the one hand, the simple mixing method makes it difficult for the fruit and coffee to fully blend, and it is easy to have a layering phenomenon, resulting in an uneven taste and unable to make the mellow taste of coffee and the freshness of fruit coordinated and unified. On the other hand, the preparation process is rough, unable to accurately control the ratio of fruit and coffee, and there are also deficiencies in controlling the processing temperature and time. High-temperature processing causes a large loss of heat-sensitive nutrients in fruits (such as vitamin C and polyphenolic substances), and it is difficult to retain the volatile aromatic components of coffee beans, not only resulting in poor product flavor, but also easily causing problems such as the loss of fruit nutritional components. Therefore, in view of the above problems, this application provides a fruit coffee and its preparation method. By optimizing the raw material ratio and process design, the unique flavor of the coffee beverage is achieved, and the functionality of the coffee beverage is increased to meet the market demand for high-quality coffee beverages. Summary of the Invention

[0004] In order to solve the technical problems mentioned in the background art, this application provides a fruit coffee and its preparation method.

[0005] In the first aspect, this application provides a fruit coffee, adopting the following technical solution: A fruit coffee, comprising the following raw materials in parts by weight: 30 - 50 parts of compound coffee liquid, 20 - 35 parts of fresh milk, 1 - 3 parts of flavor regulator, 3 - 5 parts of dietary fiber, and 1 - 2 parts of stabilizer.

[0006] Preferably, the preparation method of the compound coffee liquid comprises the following preparation steps: Step a: Add coffee beans into the fermentation broth, inoculate with Pichia pastoris, ferment aerobically at a temperature of 28 - 30 °C for 18 - 24 h, then inoculate with Lactobacillus plantarum, raise the temperature to 30 - 35 °C, ferment aerobically for 5 - 8 h, and then ferment anaerobically for 15 - 20 h. After fermentation, wash and dry to obtain fermented coffee beans; Step b: Bake the fermented coffee beans. After baking, crush them to 1 - 5 mm to obtain coffee powder. Add the coffee powder into distilled water and perform ultrasonic extraction at 30 - 40 °C for 15 - 20 min to obtain coffee extract; Step c: Mix oranges, raspberries, lychees and distilled water, break them to obtain a mixture, add pectinase, enzymatically hydrolyze for 2 - 4 h, adjust the sugar content and acidity to obtain the pre - treatment material for fermentation; Step d: First inoculate the pre - treatment material for fermentation with Saccharomyces cerevisiae, ferment anaerobically at 20 - 25 °C for 3 - 5 days. Wait until the acidity value stabilizes at 3.5 - 3.8, then inoculate with Acetobacter pasteurianus, ferment at 30 - 35 °C for 2 - 4 days, and then inoculate with Lactobacillus acidophilus, ferment at 25 - 35 °C for 3 - 5 days. After fermentation, carry out airtight aging at 0 - 4 °C for 5 - 8 days, and then filter to obtain fruit fermentation broth; Step e: Mix the fruit fermentation broth and the coffee extract evenly to obtain the compound coffee liquid.

[0007] Preferably, in step a, the fermentation broth is composed of glucose, peptone and distilled water with a mass ratio of 2 - 5:0.5 - 1:100.

[0008] Preferably, in step a, the coffee beans are one or several of Arabica coffee beans, Robusta coffee beans and Liberica coffee beans.

[0009] Preferably, in step a, the mass ratio of the coffee beans to the fermentation broth is 4 - 6:10 - 12.

[0010] Preferably, in step a, the inoculation amount of Pichia pastoris is 1 - 3% of the coffee beans.

[0011] Preferably, in step a, the inoculation amount of Lactobacillus plantarum is 2 - 3% of the coffee beans.

[0012] Preferably, the conditions for the baking treatment in step b are: preheat at 180 - 190 °C for 3 - 5 min, raise the temperature to 210 - 220 °C, bake for 15 - 20 min, lower the temperature to 160 - 170 °C, and keep warm for 5 - 10 min.

[0013] Preferably, in step b, the mass ratio of the coffee powder to the distilled water is 1:3 - 5.

[0014] Preferably, in step c, the mass ratio of oranges, raspberries, lychees and distilled water is 5 - 8:1 - 3:1 - 2:10 - 15.

[0015] Preferably, the addition amount of pectinase in step c is 0.05 - 0.2 wt% of the mixture.

[0016] Preferably, the sugar degree in step c is adjusted to 16 - 20 Brix.

[0017] Preferably, the acidity in step c is adjusted to a pH value of 4.0 - 4.5.

[0018] Preferably, the inoculation amount of Saccharomyces cerevisiae in step d is 0.5 - 1% of the pre - fermentation treatment product.

[0019] Preferably, the inoculation amount of Acetobacter pasteurianus in step d is 2 - 4% of the pre - fermentation treatment product.

[0020] Preferably, the inoculation amount of Lactobacillus acidophilus in step d is 3 - 5% of the pre - fermentation treatment product.

[0021] Preferably, the volume ratio of the fruit fermentation broth to the coffee extract in step e is 2 - 4:1 - 1.5.

[0022] Preferably, the flavor regulator is one of fructooligosaccharide, matcha powder, coconut milk powder, and caramel essence.

[0023] Preferably, the dietary fiber is one of inulin, resistant dextrin, xylo - oligosaccharide, and galactooligosaccharide.

[0024] Preferably, the stabilizer is one or several of xanthan gum, carrageenan, and sodium carboxymethylcellulose.

[0025] Secondly, the present application also provides a preparation method of fruit coffee, adopting the following technical solution: A preparation method of fruit coffee, comprising the following preparation steps: mixing the compound coffee liquid and fresh milk, adding a flavor regulator, dietary fiber, and a stabilizer, homogenizing 3 times under a pressure of 30 - 50 MPa and a temperature of 32 - 37 °C, performing high - temperature short - time sterilization at 131 - 135 °C for 15 - 40 s, then cooling to 70 - 80 °C, and filling aseptically to obtain the fruit coffee.

[0026] To sum up, the present application has the following beneficial effects: In the process of preparing the composite coffee liquid of the present application, the coffee beans are first fermented and then roasted. Through the co-fermentation of Pichia pastoris and Lactobacillus plantarum, Pichia pastoris first produces volatile aroma substances such as esters, alcohols, and aldehydes through glycolysis and amino acid metabolism. Subsequently, Lactobacillus plantarum is inoculated, and sugars are converted into organic acids such as lactic acid and succinic acid through lactic acid fermentation. At the same time, proteins are decomposed into free amino acids and short-chain peptides. Pichia pastoris first consumes easily utilizable glucose, and Lactobacillus plantarum utilizes residual sugars and yeast metabolites to achieve gradient utilization of substrates and maximize the production of flavor substances. These substances participate in the Maillard reaction during roasting, generating richer flavors such as caramel and nutty flavors. Moreover, the accumulation of lactic acid can balance the sharp acidity of coffee and make the taste smoother. Pichia pastoris and Lactobacillus plantarum produce vitamins, short-chain fatty acids, and antioxidant substances during fermentation, endowing the beverage with additional nutritional value and synergizing with the dietary fiber added subsequently to enhance the functionality of the coffee beverage.

[0027] In the process of preparing the fruit fermentation liquid of the present application, first, Saccharomyces cerevisiae is used to convert the sugars in the fruit into alcohol and carbon dioxide under anaerobic conditions, while producing volatile aroma substances such as esters and higher alcohols to provide a basic flavor for the fermentation liquid. And alcohol is the key substrate for the subsequent fermentation of Acetobacter pasteurianus, which converts alcohol into acetic acid under aerobic conditions, further enhancing the acidity and sour taste of the fermentation liquid. Lactobacillus acidophilus converts the remaining sugars into lactic acid under anaerobic conditions, further reducing the pH and forming a complex sweet and sour taste. The ester aroma of alcohol fermentation, the sour aroma of acetic acid fermentation, and the mellow feeling of lactic acid fermentation are superimposed to form a multi-layered flavor; at the same time, the fruity aroma of the fruit itself combines with the fermentation products to enhance the complexity of the taste. The metabolism of Lactobacillus acidophilus also produces substances such as short-chain fatty acids and bacteriocins, enhancing the flavor level of the fermentation liquid, gradually reducing the pH value, and inhibiting the growth of miscellaneous bacteria to ensure the biological stability of the fermentation liquid during the subsequent aging process.

[0028] The present application combines the fermented and roasted fermentation extract with a caramel and nutty flavor obtained by Pichia pastoris and Lactobacillus plantarum with the sweet and sour taste obtained by fermenting fruits with Saccharomyces cerevisiae, Acetobacter pasteurianus, and Lactobacillus acidophilus. The sourness and fruity aroma of the fruit fermentation liquid can neutralize the bitterness of coffee and improve the overall palatability. The roasted aroma of coffee combines with the freshness of the fruit to create a multi-layered taste experience and avoid the monotony of a single flavor. In addition to improving the taste, coffee itself is rich in caffeine, chlorogenic acid, minerals, etc. The fruit fermentation liquid provides vitamins, dietary fiber, amino acids, and probiotic metabolites. After mixing, the product combines the refreshing effect of coffee and the nutritional supplement of the fruit fermentation liquid, meeting the needs of modern consumers for "functional beverages". Detailed implementation manners

[0029] The present application will be further described in detail below in conjunction with embodiments.

[0030] In the examples and comparative examples of this application, the Arabica coffee beans were purchased from Yunnan Yishanxiang Trading Co., Ltd.; the fresh milk was purchased from Guangzhou Qiangqiangxing Dairy Co., Ltd.; the fructooligosaccharide was purchased from Shandong Huiheng Biotechnology Co., Ltd.; the inulin was purchased from Hubei Haijia Biotechnology Co., Ltd.; the xanthan gum was purchased from Tianxin (Qingdao) Food Co., Ltd.; the pectinase (enzyme activity: 30,000) was purchased from Hefei Shengrun Biological Products Co., Ltd.; the Pichia pastoris (product name: Pichia manshurica, product number: BMZ131972), Lactobacillus plantarum (product name: Lactobacillus plantarum, product number: B94797), Saccharomyces cerevisiae (product name: Saccharomyces cerevisiae, product name: B98026), Acetobacter pasteurianus (product name: Acetobacter pasteurianus, product number: BMZ124442), and Lactobacillus acidophilus (product number: Lactobacillus acidophilus, product name: B98034) were all purchased from Ningbo Mingzhou Biotechnology Co., Ltd.

[0031] Examples 1-3 provide a fruit coffee and its preparation method.

[0032] Example 1 A fruit coffee, comprising the following raw materials in parts by weight: 30 parts of compound coffee liquid, 20 parts of fresh milk, 1 part of flavor regulator, 3 parts of dietary fiber, and 1 part of stabilizer, wherein the flavor regulator is fructooligosaccharide, the dietary fiber is inulin, and the stabilizer is xanthan gum.

[0033] Among them, the preparation method of the compound coffee liquid includes the following preparation steps: Step a: Add Arabica coffee beans to the fermentation broth, inoculate Pichia pastoris at an inoculation amount of 1% of the coffee beans, carry out aerobic fermentation at 28°C for 18 h, then inoculate Lactobacillus plantarum at an inoculation amount of 2% of the coffee beans, raise the temperature to 30°C, carry out aerobic fermentation for 5 h, and then carry out anaerobic fermentation for 15 h. After the fermentation is completed, wash and dry to obtain fermented coffee beans. Among them, the fermentation broth is composed of glucose, peptone, and distilled water with a mass ratio of 2:0.5:100; the mass ratio of Arabica coffee beans to the fermentation broth is 4:10; Step b: Preheat the fermented coffee beans at 180°C for 3 min, raise the temperature to 210°C, bake for 15 min, lower the temperature to 160°C, and keep warm for 5 min. After the baking is completed, crush to 1 mm to obtain coffee powder. Add the coffee powder to distilled water, and carry out ultrasonic extraction at 30°C for 15 min, with an ultrasonic power of 150 W and an ultrasonic frequency of 40 KHz to obtain a coffee extract. Among them, the mass ratio of coffee powder to distilled water is 1:3; Step c: Mix oranges, raspberries, lychees and distilled water, break them to obtain a mixture, add 0.05 wt% pectinase to the mixture, enzymatically hydrolyze for 2 h, adjust the sugar content to 16 Brix and the acidity to a pH value of 4.0 to obtain a pre-fermentation treatment product. Among them, the mass ratio of oranges, raspberries, lychees and distilled water is 5:1:1:10; Step d: First, inoculate Saccharomyces cerevisiae into the pre-fermentation treatment product at an inoculation amount of 0.5% of the pre-fermentation treatment product, anaerobically ferment at 20 °C for 3 days. Wait until the acidity value stabilizes at 3.5, then inoculate Acetobacter pasteurianus at an inoculation amount of 2% of the pre-fermentation treatment product, ferment at 30 °C for 2 days, and then inoculate Lactobacillus acidophilus at an inoculation amount of 3% of the pre-fermentation treatment product, ferment at 25 °C for 3 days. After fermentation is completed, age hermetically at 0 °C for 5 days, filter to obtain a fruit fermentation broth; Step e: Mix the fruit fermentation broth and coffee extract in a volume ratio of 2:1, and after mixing evenly, a compound coffee liquid is obtained.

[0034] A method for preparing fruit coffee specifically includes the following steps: Mix the compound coffee liquid and fresh milk, add a flavor regulator, dietary fiber and a stabilizer, homogenize 3 times at a pressure of 30 MPa and a temperature of 32 °C, perform high-temperature short-time sterilization at 131 °C for 15 s, then cool to 70 °C, and perform aseptic filling to obtain fruit coffee.

[0035] Example 2 A fruit coffee includes the following raw materials in parts by weight: 40 parts of compound coffee liquid, 28 parts of fresh milk, 2 parts of flavor regulator, 4 parts of dietary fiber, and 1.5 parts of stabilizer. Among them, the flavor regulator is fructooligosaccharide, the dietary fiber is inulin, and the stabilizer is xanthan gum.

[0036] Among them, the preparation method of the compound coffee liquid includes the following preparation steps: Step a: Add Arabica coffee beans to the fermentation broth, inoculate Pichia pastoris at an inoculation amount of 2% of the coffee beans, first aerobically ferment at a temperature of 29 °C for 21 h, then inoculate Lactobacillus plantarum at an inoculation amount of 2.5% of the coffee beans, raise the temperature to 32 °C, aerobically ferment for 7 h and then anaerobically ferment for 18 h. After fermentation is completed, wash and dry to obtain fermented coffee beans. Among them, the fermentation broth consists of glucose, peptone and distilled water with a mass ratio of 3:0.8:100; the mass ratio of Arabica coffee beans and the fermentation broth is 5:11; Step b: Preheat the fermented coffee beans at 185°C for 4 min, then raise the temperature to 215°C and roast for 18 min. Next, lower the temperature to 165°C and keep warm for 8 min. After roasting, crush the beans to 3 mm to obtain coffee powder. Add the coffee powder to distilled water, and perform ultrasonic extraction at 35°C for 18 min with an ultrasonic power of 180 W and an ultrasonic frequency of 50 KHz to obtain coffee extract. Here, the mass ratio of coffee powder to distilled water is 1:4; Step c: Mix oranges, raspberries, lychees and distilled water, break them to obtain a mixture, add 0.1 wt% pectinase to the mixture, enzymatically hydrolyze for 3 h, adjust the sugar content to 18 Brix and the acidity to a pH value of 4.2 to obtain a pre-fermentation treatment product. Here, the mass ratio of oranges, raspberries, lychees and distilled water is 7:2:1.5:12; Step d: First, inoculate the pre-fermentation treatment product with Saccharomyces cerevisiae at an inoculation amount of 0.8% of the pre-fermentation treatment product, and perform anaerobic fermentation at 22°C for 4 days. Wait until the acidity value stabilizes at 3.7, then inoculate Acetobacter pasteurianus at an inoculation amount of 3% of the pre-fermentation treatment product, and ferment at 32°C for 3 days. Then, inoculate Lactobacillus acidophilus at an inoculation amount of 4% of the pre-fermentation treatment product, and ferment at 30°C for 4 days. After fermentation, carry out sealed aging at 2°C for 7 days, and then filter to obtain fruit fermentation broth; Step e: Mix the fruit fermentation broth and the coffee extract in a volume ratio of 3:1.2, and after mixing evenly, the compound coffee liquid is obtained.

[0037] A method for preparing fruit coffee specifically includes the following steps: Mix the compound coffee liquid and fresh milk, add flavor regulators, dietary fiber and stabilizers, homogenize 3 times at a pressure of 40 MPa and a temperature of 35°C, perform high-temperature short-time sterilization at 133°C for 30 s, then cool to 75°C, and perform aseptic filling to obtain fruit coffee.

[0038] Example 3 A fruit coffee includes the following raw materials in parts by weight: 50 parts of compound coffee liquid, 35 parts of fresh milk, 3 parts of flavor regulator, 5 parts of dietary fiber, and 2 parts of stabilizer. Here, the flavor regulator is fructooligosaccharide, the dietary fiber is inulin, and the stabilizer is xanthan gum.

[0039] Among them, the preparation method of the compound coffee liquid includes the following preparation steps: Step a: Add Arabica coffee beans to the fermentation broth. Inoculate Pichia pastoris at an inoculation amount of 3% of the coffee beans, and perform aerobic fermentation at 30°C for 24 h. Then, inoculate Lactobacillus plantarum at an inoculation amount of 3% of the coffee beans, raise the temperature to 35°C, perform aerobic fermentation for 8 h, and then perform anaerobic fermentation for 20 h. After fermentation, wash and dry to obtain fermented coffee beans. Among them, the fermentation broth consists of glucose, peptone, and distilled water with a mass ratio of 5:1:100; the mass ratio of Arabica coffee beans to the fermentation broth is 6:12. Step b: Preheat the fermented coffee beans at 190°C for 5 min, raise the temperature to 220°C, bake for 20 min, lower the temperature to 170°C, and keep warm for 10 min. After baking, crush to 5 mm to obtain coffee powder. Add the coffee powder to distilled water, and perform ultrasonic extraction at 40°C for 20 min with an ultrasonic power of 200 W and an ultrasonic frequency of 60 KHz to obtain coffee extract. Among them, the mass ratio of coffee powder to distilled water is 1:5. Step c: Mix oranges, raspberries, lychees, and distilled water, and obtain a mixture after crushing. Add 0.2 wt% pectinase to the mixture, enzymatically hydrolyze for 4 h, adjust the sugar content to 20 Brix, and the acidity to a pH value of 4.5 to obtain the pre-fermentation treatment product. Among them, the mass ratio of oranges, raspberries, lychees, and distilled water is 8:3:2:15. Step d: First, inoculate Saccharomyces cerevisiae at an inoculation amount of 1% of the pre-fermentation treatment product, and perform anaerobic fermentation at 25°C for 5 days. Wait until the acidity value stabilizes at 3.8, then inoculate Acetobacter pasteurianus at an inoculation amount of 4% of the pre-fermentation treatment product, and ferment at 35°C for 4 days. Then, inoculate Lactobacillus acidophilus at an inoculation amount of 5% of the pre-fermentation treatment product, and ferment at 35°C for 5 days. After fermentation, perform sealed aging at 4°C for 8 days, and filter to obtain fruit fermented liquid. Step e: Mix the fruit fermented liquid and the coffee extract in a volume ratio of 4:1.5, and after mixing evenly, obtain the compound coffee liquid.

[0040] A preparation method of fruit coffee specifically includes the following steps: Mix the compound coffee liquid and fresh milk, add flavor regulators, dietary fiber, and stabilizers, homogenize 3 times at a pressure of 50 MPa and a temperature of 37°C, perform high-temperature instantaneous sterilization at 135°C for 40 s, then cool to 80°C, and perform aseptic filling to obtain fruit coffee.

[0041] Comparative Example 1 A fruit coffee includes the following raw materials in parts by weight: 30 parts of compound coffee liquid, 20 parts of fresh milk, 1 part of flavor regulator, 3 parts of dietary fiber, and 1 part of stabilizer. Among them, the flavor regulator is fructooligosaccharide, the dietary fiber is inulin, and the stabilizer is xanthan gum.

[0042] Among them, the preparation method of the compound coffee liquid includes the following preparation steps: Step a: Add Arabica coffee beans to the fermentation broth. Inoculate Pichia pastoris at an inoculation amount of 3% of the coffee beans. Ferment aerobically at 28°C for 38 hours. After fermentation, wash and dry to obtain fermented coffee beans. Among them, the fermentation broth is composed of glucose, peptone, and distilled water with a mass ratio of 2:0.5:100; the mass ratio of Arabica coffee beans to the fermentation broth is 4:10. Step b: Preheat the fermented coffee beans at 180°C for 3 minutes, raise the temperature to 210°C, bake for 15 minutes, lower the temperature to 160°C, and keep warm for 5 minutes. After baking, crush to 1 mm to obtain coffee powder. Add the coffee powder to distilled water, and perform ultrasonic extraction at 30°C for 15 minutes. The ultrasonic power is 150 W, and the ultrasonic frequency is 40 KHz to obtain coffee extract. Among them, the mass ratio of coffee powder to distilled water is 1:3. Step c: Mix oranges, raspberries, lychees, and distilled water, break them to obtain a mixture, add 0.05 wt% pectinase to the mixture, enzymatically hydrolyze for 2 hours, adjust the sugar content to 16 Brix, and the acidity to a pH value of 4.0 to obtain the pre-fermentation treatment product. Among them, the mass ratio of oranges, raspberries, lychees, and distilled water is 5:1:1:10. Step d: First, inoculate Saccharomyces cerevisiae into the pre-fermentation treatment product at an inoculation amount of 0.5% of the pre-fermentation treatment product. Ferment anaerobically at 20°C for 3 days. When the acidity value stabilizes at 3.5, then inoculate Acetobacter pasteurianus at an inoculation amount of 2% of the pre-fermentation treatment product. Ferment at 30°C for 2 days, and then inoculate Lactobacillus acidophilus at an inoculation amount of 3% of the pre-fermentation treatment product. Ferment at 25°C for 3 days. After fermentation, carry out airtight aging at 0°C for 5 days, and filter to obtain fruit fermentation broth. Step e: Mix the fruit fermentation broth and the coffee extract in a volume ratio of 2:1, and after mixing evenly, the compound coffee liquid is obtained.

[0043] A preparation method of fruit coffee specifically includes the following steps: Mix the compound coffee liquid and fresh milk, add flavor regulators, dietary fiber, and stabilizers, homogenize 3 times at a pressure of 30 MPa and a temperature of 32°C, perform high-temperature short-time sterilization at 131°C for 15 s, then cool to 70°C, and perform aseptic filling to obtain fruit coffee.

[0044] Comparative Example 2 A kind of fruit coffee, including the following raw materials in parts by weight: 30 parts of compound coffee liquid, 20 parts of fresh milk, 1 part of flavor regulator, 3 parts of dietary fiber, and 1 part of stabilizer. Among them, the flavor regulator is fructooligosaccharide, the dietary fiber is inulin, and the stabilizer is xanthan gum.

[0045] Among them, the preparation method of the compound coffee liquid includes the following preparation steps: Step a: Add Arabica coffee beans to the fermentation broth. Inoculate Lactobacillus plantarum at an inoculation amount of 2% of the coffee beans, heat up to 30°C, perform aerobic fermentation for 5 h, then perform anaerobic fermentation for 15 h. Then, inoculate Pichia pastoris at an inoculation amount of 1% of the coffee beans, and perform aerobic fermentation at 28°C for 18 h. After fermentation, wash and dry to obtain fermented coffee beans. Among them, the fermentation broth consists of glucose, peptone, and distilled water with a mass ratio of 2:0.5:100; the mass ratio of Arabica coffee beans to the fermentation broth is 4:10. Step b: Preheat the fermented coffee beans at 180°C for 3 min, heat up to 210°C, roast for 15 min, cool down to 160°C, and keep warm for 5 min. After roasting, crush to 1 mm to obtain coffee powder. Add the coffee powder to distilled water, and perform ultrasonic extraction at 30°C for 15 min. The ultrasonic power is 150 W, and the ultrasonic frequency is 40 KHz to obtain coffee extract. Among them, the mass ratio of coffee powder to distilled water is 1:3. Step c: Mix oranges, raspberries, lychees, and distilled water, crush to obtain a mixture, add 0.05 wt% pectinase, enzymatically hydrolyze for 2 h, adjust the sugar content to 16 Brix, and the acidity to a pH value of 4.0 to obtain a pre-fermentation treatment product. Among them, the mass ratio of oranges, raspberries, lychees, and distilled water is 5:1:1:10. Step d: First, inoculate Saccharomyces cerevisiae at an inoculation amount of 0.5% of the pre-fermentation treatment product, perform anaerobic fermentation at 20°C for 3 days. When the acidity value stabilizes at 3.5, then inoculate Acetobacter pasteurianus at an inoculation amount of 2% of the pre-fermentation treatment product, and ferment at 30°C for 2 days. Then, inoculate Lactobacillus acidophilus at an inoculation amount of 3% of the pre-fermentation treatment product, and ferment at 25°C for 3 days. After fermentation, perform sealed aging at 0°C for 5 days, and filter to obtain fruit fermented liquid. Step e: Mix the fruit fermented liquid and the coffee extract in a volume ratio of 2:1, mix evenly to obtain a compound coffee liquid.

[0046] A method for preparing fruit coffee specifically includes the following steps: Mix the compound coffee liquid and fresh milk, add flavor regulators, dietary fiber, and stabilizers, homogenize 3 times at a pressure of 30 MPa and a temperature of 32°C, perform high-temperature short-time sterilization at 131°C for 15 s, then cool to 70°C, and perform aseptic filling to obtain fruit coffee.

[0047] Comparative Example 3 A fruit coffee includes the following raw materials in parts by weight: 30 parts of compound coffee liquid, 20 parts of fresh milk, 1 part of flavor regulator, 3 parts of dietary fiber, 1 part of stabilizer. Among them, the flavor regulator is fructooligosaccharide, the dietary fiber is inulin, and the stabilizer is xanthan gum.

[0048] Among them, the preparation method of the compound coffee liquid includes the following preparation steps: Step a: Preheat the Arabica coffee beans at 180°C for 3 minutes, raise the temperature to 210°C, bake for 15 minutes, lower the temperature to 160°C, and keep warm for 5 minutes. After the baking is completed, obtain the roasted coffee beans; Step b: Add the roasted coffee beans into the fermentation liquid, inoculate Pichia pastoris according to 1% of the inoculation amount of the roasted coffee beans, ferment aerobically at 28°C for 18 hours first, then inoculate Lactobacillus plantarum according to 2% of the inoculation amount of the roasted coffee beans, raise the temperature to 30°C, ferment aerobically for 5 hours, and then ferment anaerobically for 15 hours. After the fermentation is completed, wash, dry, and crush to 1 mm to obtain coffee powder. Add the coffee powder into distilled water, carry out ultrasonic extraction at 30°C for 15 minutes, with an ultrasonic power of 150 W and an ultrasonic frequency of 40 KHz to obtain coffee extract. Among them, the fermentation liquid is composed of glucose, peptone, and distilled water with a mass ratio of 2:0.5:100; the mass ratio of the roasted coffee beans to the fermentation liquid is 4:10; the mass ratio of the coffee powder to the distilled water is 1:3; Step c: Mix oranges, raspberries, lychees, and distilled water, break them to obtain a mixture, add 0.05 wt% pectinase to the mixture, enzymatically hydrolyze for 2 hours, adjust the sugar content to 16 Brix, and the acidity to a pH value of 4.0 to obtain the pre-fermentation treatment product. Among them, the mass ratio of oranges, raspberries, lychees, and distilled water is 5:1:1:10; Step d: First inoculate Saccharomyces cerevisiae into the pre-fermentation treatment product according to 0.5% of the inoculation amount of the pre-fermentation treatment product, ferment anaerobically at 20°C for 3 days. When the acidity value is stable at 3.5, then inoculate Acetobacter pasteurianus according to 2% of the inoculation amount of the pre-fermentation treatment product, ferment at 30°C for 2 days, then inoculate Lactobacillus acidophilus according to 3% of the inoculation amount of the pre-fermentation treatment product, ferment at 25°C for 3 days. After the fermentation is completed, carry out closed aging at 0°C for 5 days, and filter to obtain the fruit fermentation liquid; Step e: Mix the fruit fermentation liquid and the coffee extract in a volume ratio of 2:1, and after mixing evenly, obtain the compound coffee liquid.

[0049] A preparation method of fruit coffee specifically includes the following steps: Mix the compound coffee liquid and fresh milk, add a flavor regulator, dietary fiber, and a stabilizer, homogenize 3 times at a pressure of 30 MPa and a temperature of 32°C, carry out high-temperature short-time sterilization at 131°C for 15 s, then cool to 70°C, and carry out aseptic filling to obtain fruit coffee.

[0050] Comparative Example 4 A kind of fruit coffee, including the following raw materials in parts by weight: 30 parts of compound coffee liquid, 20 parts of fresh milk, 1 part of flavor regulator, 3 parts of dietary fiber, 1 part of stabilizer. Among them, the flavor regulator is fructooligosaccharide, the dietary fiber is inulin, and the stabilizer is xanthan gum.

[0051] Among them, the preparation method of the compound coffee liquid includes the following preparation steps: Step a: Add Arabica coffee beans to the fermentation broth. Inoculate Pichia pastoris at an inoculation amount of 1% of the coffee beans. Ferment aerobically at a temperature of 28°C for 18 h. Then, inoculate Lactobacillus plantarum at an inoculation amount of 2% of the coffee beans, raise the temperature to 30°C, ferment aerobically for 5 h, and then ferment anaerobically for 15 h. After fermentation, wash and dry to obtain fermented coffee beans. Among them, the fermentation broth consists of glucose, peptone, and distilled water with a mass ratio of 2:0.5:100; the mass ratio of Arabica coffee beans to the fermentation broth is 4:10; Step b: Preheat the fermented coffee beans at 180°C for 3 min, raise the temperature to 210°C, roast for 15 min, lower the temperature to 160°C, and keep warm for 5 min. After roasting, crush to 1 mm to obtain coffee powder. Add the coffee powder to distilled water, and perform ultrasonic extraction at 30°C for 15 min. The ultrasonic power is 150 W, and the ultrasonic frequency is 40 KHz to obtain coffee extract. Among them, the mass ratio of coffee powder to distilled water is 1:3; Step c: Mix oranges, raspberries, lychees, and distilled water, break them to obtain a mixture, add 0.05 wt% pectinase of the mixture, enzymatically hydrolyze for 2 h, adjust the sugar content to 16 Brix, and the acidity to a pH value of 4.0 to obtain a pre-fermentation treatment product. Among them, the mass ratio of oranges, raspberries, lychees, and distilled water is 5:1:1:10; Step d: First, inoculate Saccharomyces cerevisiae at an inoculation amount of 0.5% of the pre-fermentation treatment product, ferment anaerobically at 20°C for 3 days. Wait until the acidity value stabilizes at 3.5, then inoculate Acetobacter pasteurianus at an inoculation amount of 2% of the pre-fermentation treatment product, and inoculate Lactobacillus acidophilus at an inoculation amount of 3% of the pre-fermentation treatment product. Ferment at 30°C for 5 days. After fermentation, carry out sealed aging at 0°C for 5 days, and filter to obtain fruit fermented liquid; Step e: Mix the fruit fermented liquid and the coffee extract in a volume ratio of 2:1, mix evenly, and then obtain the compound coffee liquid.

[0052] A preparation method of fruit coffee specifically includes the following steps: Mix the compound coffee liquid and fresh milk, add flavor regulators, dietary fiber, and stabilizers, homogenize 3 times at a pressure of 30 MPa and a temperature of 32°C, perform high-temperature short-time sterilization at 131°C for 15 s, then cool to 70°C, and perform aseptic filling to obtain fruit coffee.

[0053] Comparative Example 5 A fruit coffee, comprising the following raw materials in parts by weight: 30 parts of compound coffee liquid, 20 parts of fresh milk, 1 part of flavor regulator, 3 parts of dietary fiber, and 1 part of stabilizer, wherein the flavor regulator is fructooligosaccharide, the dietary fiber is inulin, and the stabilizer is xanthan gum.

[0054] Among them, the preparation method of the compound coffee liquid includes the following preparation steps: Step a: Add Arabica coffee beans to the fermentation broth, inoculate Pichia pastoris at an inoculation amount of 1% of the coffee beans, ferment aerobically at a temperature of 28°C for 18 h, then inoculate Lactobacillus plantarum at an inoculation amount of 2% of the coffee beans, raise the temperature to 30°C, ferment aerobically for 5 h, and then ferment anaerobically for 15 h. After the fermentation is completed, wash and dry to obtain fermented coffee beans. Among them, the fermentation broth is composed of glucose, peptone, and distilled water with a mass ratio of 2:0.5:100; the mass ratio of Arabica coffee beans to the fermentation broth is 4:10. Step b: Preheat the fermented coffee beans at 180°C for 3 min, raise the temperature to 210°C, bake for 15 min, lower the temperature to 160°C, and keep warm for 5 min. After the baking is completed, crush to 1 mm to obtain coffee powder. Add the coffee powder to distilled water, and perform ultrasonic extraction at 30°C for 15 min. The ultrasonic power is 150 W, and the ultrasonic frequency is 40 KHz to obtain coffee extract. Among them, the mass ratio of coffee powder to distilled water is 1:3. Step c: Mix oranges, raspberries, lychees, and distilled water, break them to obtain a mixture, add 0.05 wt% pectinase to the mixture, enzymatically hydrolyze for 2 h, adjust the sugar content to 16 Brix, and the acidity to a pH value of 4.0 to obtain the pre-fermentation treatment product. Among them, the mass ratio of oranges, raspberries, lychees, and distilled water is 5:1:1:10. Step d: First inoculate Saccharomyces cerevisiae into the pre-fermentation treatment product at an inoculation amount of 0.5% of the pre-fermentation treatment product, ferment anaerobically at 20°C for 3 days. When the acidity value stabilizes at 3.5, inoculate Lactobacillus acidophilus at an inoculation amount of 3% of the pre-fermentation treatment product, ferment at 25°C for 3 days, and then inoculate Acetobacter pasteurianus at an inoculation amount of 2% of the pre-fermentation treatment product, ferment at 30°C for 2 days. After the fermentation is completed, carry out sealed aging at 0°C for 5 days, and filter to obtain fruit fermentation broth. Step e: Mix the fruit fermentation broth and the coffee extract in a volume ratio of 2:1, and after mixing evenly, the compound coffee liquid is obtained.

[0055] A preparation method of fruit coffee specifically includes the following steps: Mix the compound coffee liquid and fresh milk, add the flavor regulator, dietary fiber, and stabilizer, homogenize 3 times at a pressure of 30 MPa and a temperature of 32°C, perform high-temperature short-time sterilization at 131°C for 15 s, then cool to 70°C, and perform aseptic filling to obtain fruit coffee.

[0056] Comparative Example 6 A fruit coffee, comprising the following raw materials in parts by weight: 30 parts of compound coffee liquid, 20 parts of fresh milk, 1 part of flavor regulator, 3 parts of dietary fiber, 1 part of stabilizer, wherein the flavor regulator is fructooligosaccharide, the dietary fiber is inulin, and the stabilizer is xanthan gum.

[0057] Among them, the preparation method of the compound coffee liquid includes the following preparation steps: Step a: Add Arabica coffee beans to the fermentation broth, inoculate Pichia pastoris at an inoculation amount of 1% of the coffee beans, first perform aerobic fermentation at a temperature of 28°C for 18 h, then inoculate Lactobacillus plantarum at an inoculation amount of 2% of the coffee beans, raise the temperature to 30°C, perform aerobic fermentation for 5 h, and then perform anaerobic fermentation for 15 h. After the fermentation is completed, wash and dry to obtain fermented coffee beans. Among them, the fermentation broth is composed of glucose, peptone, and distilled water with a mass ratio of 2:0.5:100; the mass ratio of Arabica coffee beans to the fermentation broth is 4:10; Step b: Preheat the fermented coffee beans at 180°C for 3 min, raise the temperature to 210°C, bake for 15 min, lower the temperature to 160°C, and keep warm for 5 min. After the baking is completed, crush to 1 mm to obtain coffee powder. Add the coffee powder to distilled water, and perform ultrasonic extraction at 30°C for 15 min. The ultrasonic power is 150 W, and the ultrasonic frequency is 40 KHz to obtain a coffee extract. Among them, the mass ratio of coffee powder to distilled water is 1:3; Step c: Mix oranges, raspberries, lychees, and distilled water, break them to obtain a mixture, add 0.05 wt% pectinase to the mixture, enzymatically hydrolyze for 2 h, adjust the sugar content to 16 Brix, and the acidity to a pH value of 4.0 to obtain a pre-fermentation treatment product. Among them, the mass ratio of oranges, raspberries, lychees, and distilled water is 5:1:1:10; Step d: First inoculate Saccharomyces cerevisiae into the pre-fermentation treatment product at an inoculation amount of 0.5% of the pre-fermentation treatment product, perform anaerobic fermentation at 20°C for 3 days. When the acidity value stabilizes at 3.5, then inoculate Lactobacillus acidophilus at an inoculation amount of 5% of the pre-fermentation treatment product, and ferment at 25°C for 5 days. After the fermentation is completed, perform closed aging at 0°C for 5 days, and filter to obtain a fruit fermentation broth; Step e: Mix the fruit fermentation broth and the coffee extract in a volume ratio of 2:1, and after mixing evenly, the compound coffee liquid is obtained.

[0058] A preparation method of fruit coffee specifically includes the following steps: Mix the compound coffee liquid and fresh milk, add the flavor regulator, dietary fiber, and stabilizer, homogenize 3 times at a pressure of 30 MPa and a temperature of 32°C, perform high-temperature short-time sterilization at 131°C for 15 s, then cool to 70°C, and perform aseptic filling to obtain fruit coffee.

[0059] Comparative Example 7 A fruit coffee, comprising raw materials in the following parts by weight: 30 parts of compound coffee liquid, 20 parts of fresh milk, 1 part of flavor regulator, 3 parts of dietary fiber, and 1 part of stabilizer. Among them, the flavor regulator is fructooligosaccharide, the dietary fiber is inulin, and the stabilizer is xanthan gum.

[0060] Among them, the preparation method of the compound coffee liquid includes the following preparation steps: Step a: Add Arabica coffee beans to the fermentation broth. Inoculate Pichia pastoris at an inoculation amount of 1% of the coffee beans. Ferment aerobically at 28°C for 18 h, then inoculate Lactobacillus plantarum at an inoculation amount of 2% of the coffee beans, raise the temperature to 30°C, ferment aerobically for 5 h, and then ferment anaerobically for 15 h. After the fermentation is completed, wash and dry to obtain fermented coffee beans. Among them, the fermentation broth is composed of glucose, peptone, and distilled water with a mass ratio of 2:0.5:100; the mass ratio of Arabica coffee beans to the fermentation broth is 4:10. Step b: Preheat the fermented coffee beans at 180°C for 3 min, raise the temperature to 210°C, bake for 15 min, lower the temperature to 160°C, and keep warm for 5 min. After the baking is completed, crush to 1 mm to obtain coffee powder. Add the coffee powder to distilled water and perform ultrasonic extraction at 30°C for 15 min. The ultrasonic power is 150 W, and the ultrasonic frequency is 40 KHz to obtain a coffee extract. Among them, the mass ratio of coffee powder to distilled water is 1:3. Step c: Mix oranges, raspberries, lychees, and distilled water, break them to obtain a mixture, add 0.05 wt% pectinase to the mixture, enzymatically hydrolyze for 2 h, adjust the sugar content to 16 Brix, and the acidity to a pH value of 4.0 to obtain a pre-fermentation treatment product. Among them, the mass ratio of oranges, raspberries, lychees, and distilled water is 5:1:1:10. Step d: First inoculate Saccharomyces cerevisiae at an inoculation amount of 0.5% of the pre-fermentation treatment product, ferment anaerobically at 20°C for 3 days. When the acidity value stabilizes at 3.5, then inoculate Acetobacter pasteurianus at an inoculation amount of 5% of the pre-fermentation treatment product, ferment at 30°C for 5 days. After the fermentation is completed, carry out airtight aging at 0°C for 5 days, and filter to obtain a fruit fermentation broth. Step e: Mix the fruit fermentation broth and the coffee extract in a volume ratio of 2:1, and after mixing evenly, the compound coffee liquid is obtained.

[0061] A preparation method of fruit coffee specifically includes the following steps: Mix the compound coffee liquid and fresh milk, add the flavor regulator, dietary fiber, and stabilizer, homogenize 3 times at a pressure of 30 MPa and a temperature of 32°C, perform high-temperature instantaneous sterilization at 131°C for 15 s, then cool to 70°C, and perform aseptic filling to obtain fruit coffee.

[0062] Performance test The comprehensive properties of the fruit coffee prepared in Examples 1-3 and Comparative Examples 1-7 of the present application were tested separately, as follows: Taste and flavor evaluation: 30 volunteers were randomly selected to evaluate the taste and flavor of the fruit coffee prepared in Examples 1-3 and Comparative Examples 1-7. They rinsed their mouths three times repeatedly before drinking and made evaluations according to the sensory evaluation criteria in Table 1, and the average values of each index were calculated; Determination of dietary fiber content: Detection was carried out with reference to the national standard GB / T 22224-2008 "Determination of Dietary Fiber in Foods - Enzymatic Gravimetric Method and Enzymatic Gravimetric Method - Liquid Chromatography Method"; The test results are shown in Table 2.

[0063] Table 1 Sensory evaluation criteria for the taste and flavor of fruit coffee

[0064] Table 2 Comprehensive properties of the fruit coffee prepared in Examples 1-3 and Comparative Examples 1-7

[0065] As can be seen from Table 2, the fruit coffee prepared in the present application has a mellow and delicate taste, a unique flavor, good stability, and is not prone to layering and spoilage during storage and transportation. It is rich in dietary fiber, can promote digestion, enhance satiety, and has the advantages of refreshing and not easily causing insomnia.

[0066] This specific embodiment is only an explanation of the present application and does not limit the present application. After reading this specification, those skilled in the art can make modifications to this embodiment without creative contributions as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A fruit coffee, characterized in that, It comprises the following raw materials in parts by weight: 30 - 50 parts of compound coffee liquid, 20 - 35 parts of fresh milk, 1 - 3 parts of flavor regulator, 3 - 5 parts of dietary fiber, and 1 - 2 parts of stabilizer.

2. The fruit coffee according to claim 1, wherein The preparation method of the compound coffee liquid comprises the following preparation steps: Step a: Add coffee beans into the fermentation broth, inoculate Pichia pastoris, ferment aerobically at a temperature of 28 - 30 °C for 18 - 24 h first, then inoculate Lactobacillus plantarum, raise the temperature to 30 - 35 °C, ferment aerobically for 5 - 8 h, and then ferment anaerobically for 15 - 20 h. After fermentation, wash and dry to obtain fermented coffee beans. Step b: Perform roasting treatment on the fermented coffee beans. After roasting, crush them to 1 - 5 mm to obtain coffee powder. Add the coffee powder into distilled water and perform ultrasonic extraction at 30 - 40 °C for 15 - 20 min to obtain coffee extract. Step c: Mix oranges, raspberries, lychees and distilled water, break them to obtain a mixture, add pectinase, enzymatically hydrolyze for 2 - 4 h, and adjust the sugar content and acidity to obtain a pre - fermentation treatment product. Step d: First inoculate Saccharomyces cerevisiae into the pre - fermentation treatment product, ferment anaerobically at 20 - 25 °C for 3 - 5 days. When the acidity value stabilizes at 3.5 - 3.8, then inoculate Acetobacter pasteurianus, ferment at 30 - 35 °C for 2 - 4 days, then inoculate Lactobacillus acidophilus, ferment at 25 - 35 °C for 3 - 5 days. After fermentation, carry out airtight aging at 0 - 4 °C for 5 - 8 days, and filter to obtain fruit fermentation broth. Step e: Mix the fruit fermentation broth and the coffee extract evenly to obtain the compound coffee liquid.

3. The fruit coffee according to claim 2, wherein In step a, the fermentation broth consists of glucose, peptone and distilled water with a mass ratio of 2 - 5:0.5 - 1:100; the coffee beans are one or several of Arabica coffee beans, Robusta coffee beans and Liberica coffee beans; the mass ratio of the coffee beans to the fermentation broth is 4 - 6:10 - 12.

4. The fruit coffee according to claim 2, wherein In step a, the inoculation amount of Pichia pastoris is 1 - 3% of the coffee beans; the inoculation amount of Lactobacillus plantarum is 2 - 3% of the coffee beans.

5. The fruit coffee according to claim 2, wherein In step b, the conditions of the roasting treatment are: pre - heat at 180 - 190 °C for 3 - 5 min, raise the temperature to 210 - 220 °C, roast for 15 - 20 min, lower the temperature to 160 - 170 °C, and keep warm for 5 - 10 min; the mass ratio of the coffee powder to the distilled water is 1:3 - 5.

6. The fruit coffee according to claim 2, wherein In step c, the mass ratio of oranges, raspberries, lychees and distilled water is 5 - 8:1 - 3:1 - 2:10 - 15; the addition amount of pectinase is 0.05 - 0.2 wt% of the mixture; the sugar content is adjusted to 16 - 20 Brix; the acidity is adjusted to a pH value of 4.0 - 4.

5.

7. The fruit coffee according to claim 2, wherein, In step d, the inoculation amount of Saccharomyces cerevisiae is 0.5 - 1% of the pre - fermentation treatment product; the inoculation amount of Acetobacter pasteurianus is 2 - 4% of the pre - fermentation treatment product; the inoculation amount of Lactobacillus acidophilus is 3 - 5% of the pre - fermentation treatment product.

8. The fruit coffee according to claim 2, characterized in that, In step e, the volume ratio of the fruit fermentation broth to the coffee extract is 2 - 4:1 - 1.

5.

9. The fruit coffee according to claim 1, characterized in that, The flavor regulator is one of fructooligosaccharide, matcha powder, coconut milk powder, and caramel essence; the dietary fiber is one of inulin, resistant dextrin, xylooligosaccharide, and galactooligosaccharide; the stabilizer is one or several of xanthan gum, carrageenan, and sodium carboxymethylcellulose.

10. A method for preparing the fruit coffee according to any one of claims 1-9, characterized in that, The specific preparation steps are as follows: Mix the compound coffee liquid and fresh milk, add the flavor regulator, dietary fiber, and stabilizer, homogenize 3 times under a pressure of 30 - 50 MPa and a temperature of 32 - 37 °C, perform high-temperature short-time sterilization at 131 - 135 °C for 15 - 40 s, then cool to 70 - 80 °C, and fill aseptically to obtain the fruit coffee.

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