Disclosure of Invention
The invention aims to provide the instant coffee fruit tea powder with rich nutrition, and the prepared instant coffee fruit tea powder is uniform powder, is dark brown, and has uniform and glossy color; has rich coffee aroma, pure aroma, no peculiar smell and obvious aftertaste. The product has the advantages of quick dissolution, rich nutrition, certain antioxidant activity, convenient eating, and is especially suitable for industrialized production.
In order to realize the purpose, the invention is realized by the following technical scheme:
the preparation method of the instant coffee fruit tea powder comprises the following steps: the coffee fruit water-soluble substance is prepared by a spray drying method to obtain the instant coffee fruit tea powder.
Further preferably, the coffee cherry water-soluble extract is extracted by the following steps: the feed-liquid ratio of the coffee cherries to water is 1:10(g: mL), the dosage of the pectinase is 0.2-1.0% (the pectinase is added according to the volume ratio of the coffee cherries to the water, namely 0.2-1.0 g of pectinase is added into every 100mL of water), and enzymolysis is carried out for 1h at 60 ℃.
Further preferably, the coffee cherry water-soluble extract is extracted by the following steps: the feed-liquid ratio of the coffee cherries to water is 1:10(g: mL), the dosage of the cellulase is 0.2-1.0% (the cellulase is added according to the volume ratio of the cellulase to water, namely 0.2-1.0 g cellulase is added into every 100mL of water), and the enzymolysis is carried out for 1h at 50 ℃.
Further preferably, the coffee cherry water-soluble extract is extracted by the following steps: the feed-liquid ratio of the coffee cherries to the water is 1:10(g: mL), the mass ratio of the pectinase to the cellulase is 3: 1-1: 3, the mixing amount of the pectinase and the cellulase is 0.2-8.0% (the pectinase and the cellulase are added according to the volume ratio of the pectinase to the water, namely 0.2-8.0 g of the pectinase and the cellulase mixed enzyme is added into every 100mL of water), the enzymolysis pH is 3.0-7.0, the enzymolysis temperature is 30-50 ℃, and the enzymolysis time is 0.5-6 h.
More preferably, the coffee cherry is a dry coffee cherry, and is subjected to crushing treatment; filtering and centrifuging the coffee fruit water-soluble substance, concentrating under reduced pressure until the solid content is 5-25%, adding a drying aid, fully dissolving, and performing spray drying to obtain the instant coffee fruit tea powder.
Further preferably, the mass ratio of the pectinase to the cellulase is 1:2, the mixing amount of the pectinase and the cellulase is 2.5%, the enzymolysis pH is 3.5, the enzymolysis temperature is 48 ℃, and the enzymolysis time is 2.5 h.
More preferably, the solid content of the coffee fruit water-soluble substance is 18-20%; the drying aid is one of maltodextrin, beta-cyclodextrin and carboxymethyl cellulose. The drying assistant is maltodextrin, and the addition amount of the drying assistant is 30-60% (calculated by the solid content of the extracting solution); the drying assistant is beta-cyclodextrin, and the addition amount of the beta-cyclodextrin is 6-12%; the drying aid is sodium carboxymethylcellulose, and the addition amount of the drying aid is 4-10%.
Further preferably, the drying aid maltodextrin is added in an amount of 40% (based on the extract solids).
Further preferably, the target temperature of spray drying is 140-165 ℃, and the feed flow rate of spray drying is 300-450 mL/h.
Further preferably, 3500rpm centrifugation is performed for 5 min; the concentration temperature under reduced pressure was 65 ℃.
The invention has the beneficial effects that:
the processing technology is simple, and the prepared instant coffee fruit tea powder is uniform in powder, brown and uniform and glossy in color; the extraction rate of the water-soluble coffee fruit extract is high, the coffee fruit extract has strong coffee fruit fragrance and mellow taste, pure fragrance and no peculiar smell; the aftertaste is obvious. In addition, the product has the advantages of quick dissolution, rich nutrition, certain antioxidant activity, convenient eating and particular suitability for industrial production.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, preferred embodiments of the present invention will be described in detail below to facilitate understanding of the skilled person.
Examples 1 to 3
An instant coffee fruit tea powder is prepared by the following steps:
1) washing the dry coffee cherries, finely drying, crushing and sieving by a 200-mesh sieve;
2) mixing 10g of dried coffee cherry with 100mL of water (material-liquid ratio is 1g:10mL), adding 0.6% of pectinase, performing enzymolysis at 60 deg.C for 1h, boiling for 10min, and inactivating enzyme; filtering, centrifuging at 3500rpm for 5min, collecting supernatant, concentrating at 65 deg.C under reduced pressure to obtain solid 18-20% to obtain coffee fruit water soluble substance;
3) adding a drying aid, fully dissolving, spray drying at the target temperature of 140 ℃ and the feeding flow rate of 350mL/h, and spray drying to obtain the instant coffee fruit tea powder. Wherein, the kinds and the amounts of the drying aids of examples 1 to 3 are shown in Table 1.
TABLE 1 examples 1-3 drying aid types and amounts
Examples 4 to 6
An instant coffee fruit tea powder is prepared by the following steps:
1) washing the dry coffee cherries, finely drying, crushing and sieving by a 200-mesh sieve;
2) mixing 10g of dried coffee fruit with 100mL of water (material-liquid ratio is 1g:10mL), adding 1.0% of cellulase, performing enzymolysis at 50 ℃ for 1h, boiling for 10min, and inactivating enzyme; filtering, centrifuging at 3500rpm for 5min, collecting supernatant, concentrating at 65 deg.C under reduced pressure to obtain solid 18-20% to obtain coffee fruit water soluble substance;
4) adding a drying aid, fully dissolving, spray-drying at the target temperature of 160 ℃ and the feeding flow rate of 400mL/h, and spray-drying to obtain the instant coffee fruit tea powder. Wherein, the kinds and the amounts of the drying aids of examples 4 to 6 are shown in Table 2.
TABLE 2 examples 4-6 types and amounts of drying aids
Examples 7 to 9
An instant coffee fruit tea powder is prepared by the following steps:
1) washing the dry coffee cherries, finely drying, crushing and sieving by a 200-mesh sieve;
2) mixing 10g of dried coffee cherry with 100mL of water (material-liquid ratio is 1g:10mL), mixing pectinase and cellulase according to the mass ratio of 1:2, adding 2.5% of pectinase and cellulase mixed enzyme, performing enzymolysis at the pH of 3.548 ℃ for 2.5h, boiling for 10min, and inactivating enzyme; filtering, centrifuging at 3500rpm for 5min, collecting supernatant, concentrating at 65 deg.C under reduced pressure to obtain solid 18-20% to obtain coffee fruit water soluble substance;
5) adding a drying aid, fully dissolving, spray-drying at the target temperature of 155 ℃ at the feeding flow rate of 350mL/h, and spray-drying to obtain the instant coffee fruit tea powder. Wherein, the kinds and the amounts of the drying aids of examples 7 to 9 are shown in Table 3.
TABLE 3 kinds and amounts of drying aids of examples 7-9
EXAMPLES 1-9 analysis of results
1. Examples 1-9 evaluation of the preparation method of coffee nectar powder is shown in table 4.
Table 4 table for evaluation of preparation method of coffee nectar powder of examples 1 to 9
2. The physicochemical properties and antioxidant activity of the coffee berry tea powders obtained by the methods of examples 1 to 9 were analyzed (see table 5).
(1) Determination of dissolution time: taking 50mL of normal-temperature distilled water and 100mL of beaker by using a measuring cylinder, placing the beaker on a constant-temperature magnetic stirrer, then weighing 2.00g of coffee fruit tea powder and pouring into the beaker, simultaneously adjusting the rotating speed of the constant-temperature magnetic stirrer to 892r/min and starting, and recording the time required by the coffee fruit tea powder to be completely dissolved.
(2) And (3) measuring the bulk density: 2g of sample is weighed and poured into a 15mL measuring cylinder to measure the volume, and the ratio of the mass to the volume is the bulk density. The bulk density rho is m/V, wherein rho is the bulk density of the sample, m is the mass of the sample, and g; v is volume, mL.
(3) And (3) chemical composition determination: measuring moisture by a halogen moisture meter; the ash content is measured by a 550 ℃ burning method; the total sugar and polysaccharide are measured by adopting a phenol-sulfuric acid method; the total polyphenol and the total flavone are measured by adopting a forskol colorimetric method; the protein content adopts a Coomassie brilliant blue method; amino acid determination adopts ninhydrin colorimetry; the reducing sugar is measured by a3, 5-dinitrosalicylic acid (DNS) method; and (3) measuring the caffeine component in the coffee fruit tea powder by an HPLC method.
TABLE 5 physicochemical Properties of instant coffee nectar powder
(5) Research on antioxidant activity: the reducing power of the instant coffee fruit tea powder is measured by a method of Heleno et al; the removal rate of DPPH free radicals and ABTS free radicals from instant coffee nectar powder was determined according to the method of Wang et al. The results are shown in FIG. 1.
Comparative analysis
1. Method for extracting water-soluble substance of coffee fruit by enzymolysis
The extraction rate of the water-soluble substance of the coffee cherry is taken as an index for measuring the extraction effect. The extraction rate (%) of the water-soluble coffee cherry extract was 100 times the mass of the water-soluble coffee cherry extract per mass of the raw fruit.
(1) Performing single-factor test on factors influencing the extraction rate of water-soluble substances of coffee cherry, namely the usage amount of pectinase or cellulase, the mixing ratio of pectinase and cellulase, the mixing usage amount, the enzymolysis pH during mixing, the enzymolysis time, the enzymolysis temperature and the like
Influence of different pectinase dosages on the extraction rate of water-soluble substances: weighing 10g of ground coffee cherries, placing the coffee cherries in a triangular flask with a plug, adding 100mL of water, adding 0.2%, 0.4%, 0.6%, 0.8% and 1.0% of pectinase, and performing enzymolysis at 60 ℃ for 1 h. Boiling for 10min to inactivate enzyme after enzymolysis is finished, centrifuging to collect supernatant, drying, weighing the mass of the water-soluble substance of the coffee cherry, and calculating the extraction rate of the water-soluble substance of the coffee cherry, wherein the result is shown in figure 2.
Influence of different cellulase dosage on the extraction rate of aqueous solutions: weighing 10g of ground coffee cherries, placing the coffee cherries in a triangular flask with a plug, adding 100mL of water, adding 0.2%, 0.4%, 0.6%, 0.8% and 1.0% of cellulase, and performing enzymolysis for 1h at 50 ℃. Boiling for 10min to inactivate enzyme after enzymolysis is finished, centrifuging to collect supernatant, drying, weighing the mass of the water-soluble substance of the coffee cherry, and calculating the extraction rate of the water-soluble substance of the coffee cherry, wherein the result is shown in figure 3.
Influence of different mixing ratios of pectinase and cellulase on extraction rate of water soluble substances: weighing 10g of ground coffee cherries, placing the coffee cherries into a triangular flask with a plug, adding 100mL of water, adding pectinase and cellulase according to the mass ratio of 3:1, 2:1, 1:2 and 1:3, adding 0.6 percent of total enzyme, and performing enzymolysis for 1h at 40 ℃. Boiling for 10min to inactivate enzyme after enzymolysis is finished, centrifuging to collect supernatant, drying, weighing the mass of the water-soluble substance of the coffee cherry, and calculating the extraction rate of the water-soluble substance of the coffee cherry, wherein the result is shown in figure 4.
Influence of the mixing amount of pectinase and cellulase on the extraction rate of water-soluble substances: weighing 10g of ground coffee cherries, placing the coffee cherries into a triangular flask with a plug, adding 100mL of water, adding 0.2%, 0.4%, 0.6%, 0.8%, 1.0%, 2.0%, 4.0%, 6.0%, 8.0% of total enzyme according to the optimal proportion of mixed enzyme, and performing enzymolysis for 1h at 40 ℃. Boiling for 10min to inactivate enzyme after enzymolysis is finished, centrifuging to collect supernatant, drying, weighing the mass of the water-soluble substance of the coffee cherry, and calculating the extraction rate of the water-soluble substance of the coffee cherry, wherein the result is shown in figure 4.
Influence of enzymolysis pH value on extraction rate of water soluble substances when pectinase and cellulase are mixed for use: weighing 10g of ground coffee cherries, placing the ground coffee cherries into a triangular flask with a plug, adding 100mL of water, adjusting the pH value to 3.0, 4.0, 5.0, 6.0 and 7.0 in sequence, adding mixed enzyme according to the optimal proportion and the optimal dosage, and performing enzymolysis for 1h at 40 ℃. Boiling for 10min to inactivate enzyme after enzymolysis is finished, centrifuging to collect supernatant, drying, weighing the mass of the water-soluble substance of the coffee cherry, and calculating the extraction rate of the water-soluble substance of the coffee cherry, wherein the result is shown in figure 4.
Influence of enzymolysis time on extraction rate of water soluble substances when pectinase and cellulase are mixed for use: weighing 10g of ground coffee cherries, placing in a triangular flask with a plug, adding 100mL of water, adjusting the pH value to be optimal, adding mixed enzyme according to the optimal proportion and the optimal dosage, and performing enzymolysis at 40 ℃ for 0.5h, 1h, 2h, 4h and 6 h. Boiling for 10min to inactivate enzyme after enzymolysis is finished, centrifuging to collect supernatant, drying, weighing the mass of the water-soluble substance of the coffee cherry, and calculating the extraction rate of the water-soluble substance of the coffee cherry, wherein the result is shown in figure 4.
Influence of enzymolysis temperature on extraction rate of water-soluble substances when pectinase and cellulase are mixed for use: weighing 10g of ground coffee cherries, placing the ground coffee cherries in a triangular flask with a plug, adding 100mL of water, adjusting the pH value to be optimal, adding mixed enzyme according to the optimal proportion and the optimal dosage, and performing enzymolysis at 30 ℃, 35 ℃, 40 ℃, 45 ℃ and 50 ℃ for the optimal time. Boiling for 10min to inactivate enzyme after enzymolysis is finished, centrifuging to collect supernatant, drying, weighing the mass of the water-soluble substance of the coffee cherry, and calculating the extraction rate of the water-soluble substance of the coffee cherry, wherein the result is shown in figure 4.
(2) Performing orthogonal experiment on factors influencing the extraction rate of the water soluble substance of the coffee cherry, namely the mixing dosage of pectinase and cellulose, enzymolysis pH, enzymolysis time and enzymolysis temperature
In order to determine the optimal process for extracting the water-soluble coffee cherry by the enzymolysis method, according to the single-factor experimental results, only the mixed dosage (A) of pectinase and cellulose, pH (B), enzymolysis time (C) and enzymolysis temperature (D) are selected as investigation factors, the extraction rate of the water-soluble coffee cherry is taken as an investigation index, and an L9(43) orthogonal table is adopted to explore the optimal experimental conditions. The levels of the factors are shown in Table 6, and the results are shown in Table 7. As is clear from fig. 4, when the mixing ratio of pectinase and cellulase is 1:2, the extraction rate of the aqueous solution is the highest, and therefore, the mixing ratio of pectinase and cellulase is selected to be 1:2, which is the optimum mixing ratio. As is clear from Table 7, the mixing amount of pectinase and cellulose has the greatest effect on the extraction rate of an aqueous solution and shows a positive correlation, and the average value is 3 hours, so that the mixing amount is preferably 2.5%. The enzymolysis pH has great influence on the extraction rate, and when the pH is 3.5, the extraction rate is highest. The influence order of all factors on the experimental result is A > B > D > C, namely the dosage of mixed enzyme > pH > enzymolysis temperature > enzymolysis time, the optimal combination is A3B1C3D3, namely the optimal conditions for extracting the water-soluble coffee cherry by the enzymolysis method are as follows: the temperature is 48 ℃, the enzymolysis time is 2.5h, the enzymolysis pH is 3.5, and the dosage of the mixed enzyme is 2.5 percent. Proved by a verification test, the extraction rate under the condition is 56.53 percent, and the obtained water-soluble substance is the most.
TABLE 6 orthogonal test factor horizontal table for extracting water-soluble substances from coffee cherry by enzymolysis
TABLE 7 results of orthogonal experiments on the extraction of aqueous coffee cherry solutions by enzymatic hydrolysis
2. Spray drying
Mixing the above (A)3B1C3D3) Filtering and centrifuging the extracted coffee fruit water soluble substance, concentrating the extracting solution under reduced pressure until the solid content is about 20%, adding a drying aid, fully dissolving, and spray drying to obtain the instant coffee fruit tea powder.
(1) Influence of drying assistant type and additive amount on coffee fruit tea powder yield
The coffee cherry extract is a food with high sugar content, and the concentrated solution of the coffee cherry extract has high viscosity, is not suitable for direct spray drying, and needs to be added with a drying aid. Maltodextrin, beta-cyclodextrin and sodium carboxymethylcellulose are selected as drying aids, and the addition amounts of the drying aids are respectively 20-60%, 4-12% and 2-10% of the solid content of the extracting solution. Under the conditions that the solid content of the extracting solution is 20%, the feeding flow is 400mL/h and the target temperature is 160 ℃, the influence of different drying aids and the addition amount thereof on the yield of the coffee fruit tea powder obtained by spray drying and the sensory quality of the coffee fruit tea powder is researched, and the sensory evaluation standard is shown in table 8. The yield is calculated as follows:
TABLE 8 sensory quality evaluation criteria for coffee and fruit tea powder
The effect of different drying aids and their addition on the yield of spray dried coffee nectar powder and its sensory quality is shown in fig. 5. As can be seen from FIG. 5, the score was highest when the amount of maltodextrin added was 40%. When the maltodextrin is added less than 40%, the sprayed powder has a high viscosity and is liable to cake. When the addition amount of maltodextrin is more than 40%, the color and smell of the coffee fruit powder are obviously deteriorated, and the coffee fruit powder has a larger taste of maltodextrin. When beta-cyclodextrin or sodium carboxymethylcellulose is added as the drying aid of the coffee cherry extracting solution, the sensory scores of the obtained coffee cherry powder are all smaller than those of the coffee cherry powder added with maltodextrin. After the yield and the sensory score are comprehensively considered, the yield and the sensory score are the best when 40 percent of maltodextrin is added as the drying aid. Therefore, 40% of maltodextrin is determined to be most suitable to be added into the coffee berry extract as a drying aid.
(2) Influence of spray drying target temperature on coffee fruit tea powder yield
The solid content of the coffee cherry extract was 20%, 40% maltodextrin was added as a drying aid to fix the feed rate at 400mL/h, and the effect of the target spray drying temperature of 140 deg.C, 150 deg.C, 160 deg.C, 170 deg.C, and 180 deg.C on the yield of coffee cherry tea powder was investigated, and the results are shown in FIG. 6. When the target temperature is 140-180 ℃, the yield of the coffee fruit powder rises along with the rise of the temperature, when the target temperature is 160 ℃, the powder yield is highest, then along with the rise of the temperature, the yield of the coffee fruit powder is reduced, and the product has the phenomena of scorching and caking. Therefore, 160 ℃ is selected as the optimum target temperature.
(3) Influence of solid content of coffee fruit extract on yield of coffee fruit tea powder
Concentrating the coffee fruit extract under reduced pressure until the solid content is 30%, and sequentially diluting to 5%, 10%, 15%, 20% and 25%. Adding 40% maltodextrin as drying aid, spray drying at 160 deg.C and feeding flow rate of 400mL/h, and studying the influence of 5%, 10%, 15%, 20%, and 25% of extract solid content on coffee fruit tea powder yield, the result is shown in FIG. 6. When the solid content of the material is 5-20%, the yield of the coffee fruit powder rises along with the increase of the concentration of the material, and when the concentration of the fed material is higher than 20%, the yield of the coffee fruit powder falls along with the increase of the solid content of the material. Selecting 20% as the solid content of the extracting solution.
(4) Influence of spray drying feed flow on coffee and fruit tea powder yield
According to the solid content of 20% extracting solution, 40% maltodextrin is added as a drying aid, the influence of feed flow rates of 200mL/h, 300mL/h, 400mL/h, 500mL/h and 600mL/h on the yield of coffee fruit tea powder is researched by taking 160 ℃ as a spray drying target temperature, and the result is shown in figure 6. Along with the gradual increase of the feeding flow, the yield of the spray-dried coffee fruit powder slowly rises and rapidly falls after reaching the peak when reaching 400 mL/h; when the feeding flow is increased to 400mL/h, the yield of the coffee fruit powder reaches the maximum. 400mL/h was selected as the feed rate.
(5) Optimization of spray drying process parameters using orthogonal experiments
Factors influencing the powder yield of spray drying of the coffee berry tea mainly comprise a spray drying target temperature, the solid content of coffee berry extract and the material feeding flow rate, three factors and three levels are selected in order to find out the optimal spray condition of spray drying of the coffee berry tea, an orthogonal table (table 9) is designed by adopting L9(33), the optimal spray drying condition is selected by taking the coffee berry powder yield as an index, and the result is shown in table 10. As can be seen from Table 10, the primary and secondary influence of the test factors on the extraction rate of coffee cherry powder is A > B > C, i.e., the target temperature > solid content of coffee cherry extract > feed flow rate, when the amount of maltodextrin added is 40% of the solid content of coffee cherry extract. According to the range analysis, the optimal combination condition of the three factors is A1B 1C 1, namely the optimal combination condition is that when the target temperature is 155 ℃, the solid content of the extracting solution is 18 percent, and the feeding flow rate is 350mL/h, the spray drying yield of the coffee fruit powder is the highest. Under the optimal condition, the optimal spray drying parameter is subjected to 2 times of repeated verification tests, the yield is 71.71%, and the parameter is proved to be the optimal condition for spray drying of the coffee fruit powder.
TABLE 9 spray drying Process parameter orthogonal test factor horizon
TABLE 10 coffee nectar powder spray drying Quadrature test results
Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.