Carrot is rich in nutrients, contains a large amount of carotene, vitamin B, vitamin C and a variety of inorganic salts, has the effect of lung, spleen, stagnation, detoxification, rash, especially its anti-cancer effect makes it more worth . Due to its wide source, low cost, and high net rate, carrots are one of the important autumn vegetables. However, the skin of the carrot root has poor water retention capacity, and it easily loses water and affects the freshness. Therefore, its storage and processing products are very popular among people. Carrots are pretreated with raw materials, quick-frozen at -30°C quick-freezing equipment, and stored at a low temperature of -18°C to maintain the original biological active ingredients for a long period of time. The flavor and quality are unchanged, the time to market is prolonged, and the market supply is adjusted. , And is conducive to long-distance export, increase economic efficiency. First, fast frozen preservation principle. Using the low temperature below -25°C, the carrots are rapidly frozen in a very short period of time, so that many small uniform ice crystals are formed in the cells and in the intercellular spaces. Therefore, the tissue structure of the cells is not mechanically damaged and can be compared after thawing. Completely restored to its original condition. At the same time, the low temperature after freezing inhibits the metabolic activities of bacteria, molds, and other microorganisms, making them in a dormant state, which can reduce the deterioration of the vegetable body due to the action of microorganisms and extend the shelf life, and freezing the low temperature to catalyze various biochemical reactions in fruits and vegetables. Enzyme activity is inhibited, reducing the speed of various enzymatic reactions in fast-frozen vegetables, thereby delaying the consumption of vegetable color, flavor, quality and nutrition. Second, the process flow. Acceptance of raw materials → Cleaning → Finishing → Peeling → Slicing → Picking → Blanching → Cooling → Drainage → Quick freezing → Packaging → Refrigeration → Thawing III. Operational points 1. Raw material acceptance: Carrot requires the use of flesh-colored red, smooth surface without grooves, The shape is straight, the meat is tender, the pith is small, the size is uniform, there is no pest, no damage, no decay, no mark, normal root shape, fully mature raw materials. 2. Cleaning: Remove dirt, sand, and a large number of microorganisms and residual pesticides on the surface of carrots. At the same time, replace the cleaning water and keep it clean. 3. Finishing: Remove the fibrous roots on the head and surface of the carrot. 4, peeled: use manual or mechanical peeling, cut the net surface and inedible parts. 5, cut points: Generally based on the international market sales habits or customer requirements, can be divided into different shapes. Slice specifications: thickness is generally about 0.3 cm, diameter of about 3 cm (circular); diced size: 0.8-1 cm small square or orange segment; cut silk specifications: thickness 0.2 cm, length 3-4 Centimeters of filaments. 6, select: available screening method. The raw materials cut into diced, flake, and silk are sorted, and the raw materials of the same size and size are screened together, and are divided into different levels according to actual needs, so as to batch-freeze the raw materials of different levels. 7. Blanching: The sliced ​​carrots are placed in a basket and blanched in boiling water at pH 6.5-7 for 1.5-2 minutes to passivate the enzyme activity in the tissue, kill some microorganisms, and exclude some of the gas in the tissue. And some moisture. To prevent overheating and insufficiency of the blanching, stir it continuously during blanching and add 1% sodium chloride or calcium chloride as required to prevent oxidative discoloration of the product. 8. Cooling: Sub-segment cooling immediately after blanching to reduce the effect of residual heat on raw material quality and nutrient damage. First, in the flowing water tank, the first cooling was performed with tap water, and then in the cooling tank, the second cooling was performed with cold water of 0-5° C., so that the material temperature finally reached 1-5° C. 9. Drainage: Use a medium-speed centrifuge or oscillating machine to drain excess moisture from the surface. The centrifuge speed is 2000r/min and the drain time is 10-15 minutes. 10, quick-freezing: The raw material is loaded into a frozen plate or directly placed on a conveyor belt, and liquid nitrogen is used for rapid freezing. The freezing temperature is -25 DEG C. to -35 DEG C., the frozen raw material thickness is 5-7.5 cm, and the freezing time is 10 -30 minutes. 11. Packaging: In order to prevent the frozen products from dehydration, drying, wilting and oxidative discoloration, the frozen raw materials should be packaged immediately. General use of 0.06-0.08 mm polyethylene film bags, packaging capacity of 500 grams per bag is more appropriate. To prevent shortages in defrosting and refrigerated consumption, each bag should be 2-3% lighter, as appropriate. The temperature in the packaging room is 0-5°C. 12, refrigerated: Quick-frozen packaged products immediately placed at -18 °C to -21 °C, relative humidity of 95-100%, storage temperature fluctuations of 1 °C in the cold storage, to avoid recrystallization and evaporation of water, the general safe storage period 12 -15 months, and can be sold fresh at any time. 13. Thawing: There are many ways to thaw, and it can be thawed in refrigerator, room temperature, cold water, warm water or hot water. The shorter the thawing process, the better. It is better to thaw in the microwave oven. The thawed raw materials should not be heated excessively during cooking, and the cooking time should be short. Fourth, product quality standards sensory indicators. (1) Color: light red, orange; (2) taste and odor: has the taste and smell of carrots, no odor; (3) organizational morphology: carrot particles of uniform size, broken grains and irregular particles shall not exceed 3%; (4) impurities: Not allowed to exist. V. Precautions (1) Quick-frozen carrots must be treated with hot blanching, and must be cooked hot, not overcooked and overheated, otherwise their quality and flavor will be poor. (2) Drain the raw materials thoroughly so that the excess moisture on the surface can be prevented from being connected to each other or frozen in the freezing equipment after freezing. (3) When the raw materials are frozen, the thickness placed on the freezing plate or conveyor belt should not be too thick to ensure rapid and uniform freezing in a short time. (4) Quick-frozen carrots should be thawed before eating, and should be eaten immediately after thawing. They should not be put to stand at room temperature for a long time.
Low Pesticide Goji Berry,Goji Juice ,Goji Berry Plant ,Goji Berry Juice
Dried Fruit Co., Ltd. , http://www.nbgojihome.com