The deep processing of tea is to re-process the finished tea products, semi-finished products and fresh leaves in accordance with certain processing techniques and techniques to produce new beverages or foods with the characteristics of tea color, fragrance and taste. The tea deep processing products currently on the market include instant tea and various beverages and foods processed from tea juice. 1. Instant tea processing. Instant tea has the characteristics of quicker than ordinary tea. It is a kind of granule, flake or powder crystal. It has no tea residue after water solubility. It is easy to carry. It can be used for hot drinks or cold drinks. Or other beneficial ingredients can be used to produce seasoning products. Juice, spices, sugar, etc.). (1) The raw materials can be made of finished tea or semi-finished products. From the perspective of cost reduction, low-grade raw materials are generally used, and the by-products such as tea, tea, tea stems and tea are blended with a certain proportion. (2) The purpose of the leaching is to separate the active ingredient of the tea from the tea residue. The leaching method is mostly carried out by boiling water extraction, the water temperature is 95-100 ° C, and the leaching is carried out in 2 - 3 times, each time is about 10-15 minutes. The concentration of the extract was 2.53%. (3) Purification purpose is to remove the insoluble matter in the tea soup, eliminate the end of the tea, impurities and "cold after the cold", so that the instant tea has a bright soup color after brewing. Removal of impurities and crushed tea is carried out by centrifugal filtration. "Cold sputum" is a kind of milky complex of polyphenols and its oxides, theaflavins, thearubigins and caffeine. It is a taste substance of black tea. It is insoluble in cold water and affects the cold solubility of instant tea. , should be given a solution treatment. The transfer method can be carried out by enzymatic transfer (using tannase) and alkaline transfer. (4) Concentrate to remove part of the water, increase the concentration of the extract, and use potassium hydroxide or the like for drying. modeling. The concentration method is concentrated under vacuum, concentrated by cooling, and concentrated by reverse osmosis membrane. The vacuum concentration of the material is 50-60 ° C, and the concentration is 5-30%. The method has high efficiency, low cost and easy to master, but the temperature is high, which affects the quality. The advantage of freeze concentration is that it is beneficial to maintain the natural color of the tea at low temperatures, but the cost is high. The reverse osmosis membrane concentration temperature is not high, but the quality of the membrane is strict, and the membrane is easily blocked and difficult to clean. (5) Drying and removing moisture to dryness, fixing quality, and shaping. The methods are spray drying and freeze sublimation drying. The spray drying inlet temperature is 100-120 ° C, and the outlet temperature is 80-100 ° C, so that the concentrate is atomized and contacted with hot air to dry into granules or powder. Vacuum freeze-sublimation drying is to make the tea concentrate evaporate under freezing condition (below 30 ° C), and the water is directly sublimated into a gas phase to be removed. The color, fragrance and taste are better than spray drying, but the cost is high and the efficacy is low. . Instant tea granules require a large void or a hollow shape to facilitate dissolution. In order to improve the bulk density, a certain volume of carbon dioxide can be mixed into a certain volume of concentrated liquid, so that a large amount of foam is generated and then spray-dried to form a thin, intermediate hollow particle type with a particle size of 200-500 micrometers, and a bulk density. It is 911 g of 100 ml of water and has a water content of 3%. (6) Aroma recovery and aroma in the instant tea processing, many times through the high temperature, the aroma loss is more, if not recycled and flavored, it can not overcome the low defects. 1 recycling. The tea is first treated with aroma recovery, then leached and concentrated. The high temperature steam is used to excite the volatile matter of the tea aromatic substance, and the steam is used as a carrier to collect through the cooling coil, and then the aqueous liquid containing the aromatic substance is rectified to obtain an emulsion of the tea essential oil. The scented liquid after rectification is mixed by the concentration of the tea juice required for spraying, spray-dried, or sprayed directly onto the dried instant tea granules in a small amount and uniformly. The direct spray method must be finely divided, and the amount of liquid sprayed should be correctly calculated so that the moisture content of the dried instant tea is controlled below 4%. 2 aroma. Add a small amount of essence to the concentrate, no more than 1.5 ‰, and then spray drying to improve the "cooked soup taste." 2. Extraction of tea leaves. Tea juice is the basic raw material for most tea deep processing new products. The traditional tea juice extract is made from dry tea. Thousand tea first extracts water-soluble active ingredients with more than ten times of boiling water, and the extraction concentration is about 12%. Concentrated by vacuum under reduced pressure, the temperature is controlled at 60-70 ° C, the concentration ratio is 1:4, the concentration of the concentrated solution after the first concentration is 4-8%, and the second time can reach 16-32%. It consumes a lot, and the tea aroma and taste are lost. Now it is successful to directly extract fresh tea leaves from raw leaves. The method is as follows: (1) Fresh leaf treatment. The fresh leaves are first processed according to the need to extract the tea juice of different teas, such as green tea, black tea, withered, oolong tea, green, and green, in order to meet the traditional quality requirements. The black tea withering is controlled in 9-12 hours, and the withering leaves have higher water content for the purpose of pressing. Oolong tea should be lightly withered. The greening (doing green) should pay attention to controlling the water content. The temperature of the fried green (greening) should be high and the time should be short to improve the aroma. (2) Machine cutting and pulverizing fresh leaves After appropriate treatment to meet the different requirements of each tea, they are roughly cut with a feed mill and then finely cut with an LTP hammer. The feed mill speed was 200 rpm and the LTP hammer was 1400 rpm. (3) Pressing the chopped leaves into a cloth bag or wrapping them with cloth, pressing them under a vertical hydraulic press, pressing the pressure control 90-100 kg/cm 2 repeatedly until the tea juice is not squeezed, if necessary, adding water and then pressing . The concentration of fresh tea juice that was first squeezed was about 10%, the second time was about 5%, and the third time was below 3%. Different concentrations of fresh tea juice should be stored separately. High-concentration processed solid beverages, low-concentration processed liquid beverages. (4) The ultrafiltration concentrated fresh tea juice is first subjected to coarse filtration to remove impurities and precipitates, and then ultrafiltration is carried out to separate the larger molecular weight portion, and the smaller molecular weight portion is subjected to reverse osmosis concentration, for example, the concentration ratio is 1:4. 10% concentration of fresh tea juice can reach 40% concentration after concentration, and 5% concentration of fresh tea juice can reach 20% concentration. The leaf juice can be stored for use after being preserved. 3. Canned tea processing. With the continuous improvement of people's living standards, they have put forward higher requirements for beverages, and have become more and more naturalized and naturalized. Due to the development of society and the accelerated pace of life, beverages are required to be fast, sanitary and convenient. Therefore, canned tea water came into being and developed rapidly. The processing technology of canned tea is as follows: (1) Leaching To prevent discoloration of tea soup, pure water containing metal ions should be used, soaked in hot water of 90 ° C or higher for 3-5 minutes. After removing the tea residue, it is filtered with industrial filter paper or 200 mesh nylon cloth, and then cooled. Stock solution. (2) Dispensing The concentrated stock solution is diluted with pure water to the drinking concentration. When the pH value is adjusted, a very small amount of sodium hydrogencarbonate is added, and a very small amount of sodium ascorbate is added as an antioxidant. After the prepared blending solution is checked for color, aroma, turbidity, etc. (3) The potting solution is heated to 90-95 °C through a heat exchanger, and the tank is filled in a hot pack to remove the residue in the tank. Oxygen, in order to prevent deterioration, can be nitrogen-filled. (4) After sterilizing and filling, the can is placed in a distillation crucible for autoclaving at about 115 ° C for 20 minutes or at 120 ° C for 7 minutes. (5) After cooling and autoclaving, it is cooled in time. 4. Fruit tea beverage processing. At present, there are many kinds of scented teas and fruit-flavored teas on the market, and the production process is different, but the process links are basically the same. The main points are as follows: (1) The water treatment tea is rich in tea polyphenols, if there is water When iron ions are present, a brown complex is formed, which causes the beverage to be dark or flocculate, which affects the quality of the beverage. Bacteria in water are also highly prone to growth in beverages rich in organic matter and sugar. To this end, water should be treated in four levels. Firstly, it is precipitated by quartz sand precipitator. The precipitator can be modified with type 112 sand core filter. The inner part is composed of quartz sand with 0.3-0.5 mm particle size, 8 cm sponge foam and two layers of 2 mm wool felt. The inlet pressure is not more than 2 kg/cm 2 , the outlet pressure is not less than 1.8 kg/cm 2 , and the flow rate is 800 kg/hr. The water is pretreated, precipitated, and adsorbed. Then it is filtered by two-stage sand core filter. The sand core filter adopts 106 type, the size is 450×420×10 mm, two series filter, the inlet pressure is not more than 1.8 kg/cm 2 , and the outlet pressure is not less than 1.6 kg/square. Cm, flow rate 800 kg / hour, treated water, total bacteria ≤ 10 / ml, coliform ≤ 3 100 ml. Finally, it is filtered by electrostatic silver ion filter. The filter type is B-1, the diameter is 600, the height is 2320 mm, the inlet pressure is not more than 1.6 kg/cm 2 , the outlet pressure is not less than 1.5 kg/cm 2 , and the flow rate is 2000 kg. /hour. Part of the treated water can be used for the extraction of raw materials, and a part of it is cooled to 2-4 ° C in a freezer for vapor-liquid mixing. The cooling water is mixed with carbon dioxide at a pressure of 4-4.5 kg/cm 2 in a vapor-liquid mixer. Mix well, keep the water temperature below 5 °C, promote carbon dioxide dissolved in water, form carbonated water and bottle. (2) Washing of the bottle. Fruit tea drinks are generally packed in 250 ml standard soda bottles. In order to ensure hygiene, in addition to the conventional washing bottle, it is necessary to dip the bottle with 2-3 ‰ *** solution for 3 minutes, and it must be thoroughly washed after disinfection. The two-stage sand filter water is used for spraying outside the bottle. (3) Treatment of tea. Generally, medium and low grade tea is used as raw material, and the concentration of the extract should be no less than 2%, and vacuum filtration is used for vacuum filtration. The filter cloth is made of 150-200 mesh nylon filter cloth, and the industrial filter cloth of No. 120-13 and No. 120-1 can be used conditionally. It is also possible to use a plate and frame filter for multi-stage fine filtration on the basis of coarse filtration. The extracted tea leaves were extracted from the tea slag using a 2000 rpm filter. (4) Excipient treatment. Vegetal raw materials can be disinfected by either pre-treatment or post-treatment. The pretreatment is generally carried out by high-pressure high-temperature sterilization, and is maintained at a pressure of 1.05-1.1 kg/cm 2 for 15-20 minutes at a temperature not higher than 150 ° C. The post-treatment is pasteurized, and the extract is sterilized at a high temperature. . Flavoring agents and coloring agents can be selected from 112171 in the United States, 6437 and 1437 in Shanghai, and 560D and 5183 in Hangzhou. The acidifier mainly uses citric acid and phosphoric acid, and the dosage is 1.2-1.5 总 in the total volume, the pH value is controlled at 34, and the acidity is appropriately adjusted at a high temperature. The sweetener is mixed in proportion with fructose and sucrose, and then mixed with water to make a mixed sugar liquid. The sugar content of the fruit tea is controlled between 5 and 6 degrees. In summer, the acidity is appropriately increased, the sugar content is lowered, and the taste is enhanced. (5) Ingredients. The irrigation and assembly materials are strictly in accordance with the production formula and the established procedures, and finally the acidity is adjusted with citric acid. Filling must be carried out according to the principle of first filling carbonated water and then grouting. First, 220 ml of carbonated water was placed, the water temperature was 4-6 ° C, and then 30 ml of the slurry was poured. Glanding, labeling, packing, warehousing, etc. are carried out according to the method of conventional beverage production. Sweet Potato Pasta With Purple Potato Sweet Potato Pasta Sauce,Sweet Potato Pasta With Purple Potato,Organic Sweet Potato Pasta With Purple Potato,Purple Potato Pasta Hebei Abiding Co.Ltd , http://www.hebeiabiding.com
Instant tea and tea beverage deep processing skills