常见速冻蔬菜生产技术要点（Technical points of common frozen vegetable production）

1、常见速冻蔬菜生产技术要点（Technical points of common frozen vegetable production）PrefaceVegetables are essential foods in peoples lives. They are rich in VC, carotene, minerals and other nutrients. Vegetable harvest is very seasonal, and has a certain regional, resulting in perennial balanced supply difficulties

2、. In addition, vegetables contain a large amount of water, and its chemical composition is a good substrate for microbial development, so if stored at room temperature for a long time, it will reduce the quality of vegetables, and even rot. Therefore, it is very important to use low temperature, esp

3、ecially fast freezing method to preserve vegetables.Suitable for many kinds of vegetables frozen processing, fruit and vegetables (edible part of the fruit and vegetables are tender seeds): green beans, cowpea, peas, beans, eggplant, tomatoes, green peppers, pepper, cucumber, pumpkin, gourd, pumpkin

4、; leafy vegetables (edible part of fresh leaves and petioles) are: spinach, celery, leek, garlic, Chinese cabbage, rape, coriander; stem vegetables (edible part is tender stem and stem): potatoes, taro, lettuce, asparagus, bamboo shoots, Toona sinensis; root vegetables (edible root): carrot, yam etc

5、. cauliflower; (edible part is dish of floral organs) are cauliflower; edible fungi (edible part is non-toxic fungus fruiting): fresh mushroom, mushroom, such as letinous edodes phoenix.1 green beans1.1 before freezing treatmentFor frozen green beans should be fresh, bright green color, uniform bar,

6、 slender, no spots, no pests and diseases, no other pollution. Where there are diseases and insect pests, abrasions, deformities will be eliminated; no side reinforcement varieties should be cut to both ends of the tip; with side reinforcement of the species to remove the side tendons, cut the tip o

7、f both ends. Then rinse the green beans in clean water 34 times.1.2 blanching and coolingIn 93 100 DEG C hot water blanching 1.5 2min, the green beans green and not a piebald. The blanching time and the degree of blanching should be strictly controlled. The blanching must be constantly stirred so as

8、 to keep the blanching evenly. The ironing tool is suitable for weaving baskets with stainless steel nets.The raw material after blanching with tap water or groundwater cooling comply with the hygiene requirements, then put in the cold water temperature is 5 degrees Celsius in the cooling tank for c

9、ooling, so that the raw material is cooled to 10 DEG C, and then the water drain material surface.1.3 quick freezing and cold storageIn a quick freezing device with a temperature below -30 DEG C, frozen 10min. is packaged into 0.25kg, 0.5kg, 1.5kg, 10kg and 20kg packages. And then carton packaging,

10、each case 20kg. frozen warehouse temperature of -18 degrees, layered pile, to prevent extrusion.2 peas2.1 pretreatmentFresh pea pods to peel, Machinable 24kg artificial shell per hour; mass production should use mechanical stripping pods per hour after stripping 2000kg. to pod beans should be 7 8mm,

11、 9 10mm, more than 11mm of various specifications, processing respectively according to the sales requirement. Mechanical shelling should avoid mechanical damage as far as possible.2.2 blanching and coolingThe beans are packed in a hot water of 100 DEG C, blanching for 1 1.5min, and the length of bl

12、anching time shall be determined according to the size and maturity of pea granules. Cool the material after blanching to below 10 degrees, then drain the water away from the surface.2.3 quick freezing and cold storageAfter processing, the pea is frozen by a bucket elevator, a vibrating cloth and a

13、conveyor belt into a single body freezing device. If the material is suspended in a fluidized bed, the freezing time is 7 10min. when the freezing temperature is -30 degrees centigradePacking according to various specifications, plastic bags or boxed seals should be tight. Refrigerate in a low tempe

14、rature freezer at -18 degrees. Avoid extrusion when stacking.3 cowpeaRaw materials should be fresh, bright green color, no pests, no spots, no deformity, cleaning 23 times. In the boiling water at 100 degrees Celsius, blanching for 1.5 2min (hot water at the time of blanching) should not be lower th

15、an 93 DEG C, remove and cool in a clean water tank, and then cool down to 10 degrees below the cooling pool. Avoid the excessive loss of soluble substances caused by blanching. Cut into several segments after cooling and then freeze, pack and refrigerate. No need to segment frozen cowpea should be p

16、ackaged, frozen, and chilled.4 fresh broad beansChoose green broad bean ripe shell as raw material, after immersed in 2% saline in 20 30min, in order to prevent discoloration. Remove from brine and wash in clean water. In 1.5% the magnesium acetate solution of 100 DEG C, in 30s of blanching, remove

17、and placed at 10 to 20 DEG C and then slowly cooling water, cooling water at 5 DEG C to 10 DEG C, the water freezing, and frozen peas and method of packaging the same.5.After picking beans, should be transported to the processing site in the shortest possible time, long pods will turn yellow. Wash w

18、ith pods and heat 3 5min in hot water above 93 degrees Celsius. Remove and cool quickly to below 10 centigrade.Remove the surface water by centrifugal mechanical vibration draining machine, then IQF, small packaged refrigeration.6 eggplant6.1 pretreatmentSelect mature, fresh, no pests, no damage, no

19、 microbial or pesticide contamination of raw materials, one by one to select, reject substandard products.After a strict selection of raw materials, steamed processing, should be washed and steamed stalks. Should be peeled peeled for frying. Artificial peeled to thin, small loss, yield rate is high.

20、 Generally cut into block, strip or flake, whichever shape to prevail, for burning eggplant, can be processed into block or strip; used for fried eggplant, can be processed into a film, and so on.In order to prevent discoloration, should immediately hang paste. Will be cut after the eggplant pieces

21、into wet starch, hang paste, hang paste how much, should be varieties. Generally starching than hanging paste, paste up both fuel and beautiful appearance; eggplant Guahu block after boiling in the pan fried inserted immediately, golden yellow is the most appropriate general. Lard, soybean oil and o

22、ther vegetable oils can be used for frying eggplant. Experience has shown that lard and soybean paste are the best products; fried eggplant should be placed on stainless steel net residue.6.2 cooling and quick freezingSteamed or fried eggplants must be pre cooled before freezing. Cooling methods are

23、 generally air-cooled, but must be guaranteed no dust or other pollution.For fried eggplant: it can be frozen directly into the fluidized bed freezer under -30 degrees Celsius. It can also be placed in the tray and frozen on the tray of the tunnel trolley. Steamed eggplant: after cooling, it is pack

24、ed in plastic bags and placed on a pallet. It is frozen in a frozen tunnel under -30 degrees celsius. After freezing, quantitative packing or with outer packing, stored at -18 degrees Celsius in the warehouse.7 tomatoesMethod 1: choose ripe and suitable fruit as raw material, and will have diseases

25、and insect pests, cracking, deformity or immature elimination. Use 0.5% 1% calcium chloride solution to soak 20min or so, drain the surface water and freeze in the frozen tunnel under -30 degrees celsius. Using this method, the freezing speed should not be too fast, otherwise it will appear brittle

26、cracking, affecting quality.Method two: processing before freezing is the same as method one. 10min at -30 DEG C after freezing, immediately placed 30 35 Deg. C water, make the tomato skin crack, artificial skin, quantitative in a plastic bag, and then frozen at -30 DEG C, the center temperature fre

27、ezing storage temperature to -18 degrees.8 green peppers8.1 pretreatmentChoose fresh sweet green pepper (Shi Zijiao) as raw material. Sweet green pepper to a big flesh, are small, bright color (green) pests, hot spot, not bad. After picking, should be processed as soon as possible, generally process

28、ed in 24h. Raw materials into the factory, after a rigorous selection, and then cleaned 23 times. According to consumer requirements can be processed into 3 kinds: on the cut: the green peppers cut longitudinally into two pieces, pedicel, cover, seed; diced: cut to the net cover, two pieces of pedic

29、el and seed, then cut into 10 15mm3 of the box; cut the width of the strip cutter. Will be cut into green pepper, rinse with water, wash floating seeds.8.2 blanching, cooling and drainingIn the hot water at 100 degrees, blanching 2min. blanching process can also be done without direct freezing. But

30、the need for cooling and draining.8.3 freeze, pack, refrigerateAfter the raw material is frozen 10min (freezing temperature -35 DEG C), the quantity is packaged and refrigerated.9 chili peppersThe green or red chili pepper as raw materials, to bright color, plump, spicy, no pests, no spots. 23 times

31、 of cleaning, cooling and draining to handle after the freezing.10 cucumberQuick frozen cucumber is a kind of quick-frozen food which is popular among the masses. Raw materials require fresh meat, more meat, less seeds, the best cucumber in autumn. The best day picking the same day processing, stora

32、ge time is not more than 24h., raw materials into the factory should be cleaned, in the concentration of 5 to 10g/L of calcium chloride solution soaked 20min, and then washed with water. According to the habit of cooking, slicing or cutting, segmentation can be used manually, but also mechanical, ma

33、nual segmentation, not suitable for mass production. When using mechanical cutting, advanced cutting machine should be selected to reduce the loss of juice. Can not use the extrusion type slicing machine, because this equipment will make the internal organization of fruit and vegetable juice squeeze

34、d out, not only increases the weight loss, but also because of too much juice bar surface, caused by freezing into Tuo, frozen goods quality influence. In order to prevent the products from sticking to frozen lump during the processing, it is most suitable to freeze them by adopting vibrating fluidi

35、zed quick freezing equipment. After freezing, quantitative packing, refrigerated in the warehouse at -18 degrees centigrade. In the refrigeration, transportation, sales links should be handled with care, to prevent extrusion.11 summer squashThe selection of raw materials, ripe peeled, cut in half, s

36、crape pulp and seeds,Immersion in the concentration of 5 to 10g/L of calcium chloride solution, 20min, remove and wash with water, as needed, processed into a piece or block, at -30 degrees Celsius in the low temperature frozen 10min, and then quantitative packaging, cold storage.12 pumpkinThere are

37、 frozen pumpkin block and quick-frozen pumpkin sauce two kinds of products.12.1 quick-frozen pumpkin chunksThe fresh pumpkin peeled, cut in half, scrape pulp and seeds, wash, cut into cubes of about 35mm3. In 100 degrees Celsius hot water blanching 5 6min, and then cooled to 10 DEG C, drained and fr

38、ozen in freezing device, and packaging.12.2 quick frozen pumpkin jamThe fresh pumpkin peeled, cut in half, scrape pulp and seeds, steamed and then cut into strips, artificial mash or blender broke into paste, packing in rapid cooling to 10 DEG, and rapid freezing.13 sweet corn (green corn)The ripe s

39、weet corn, yellow and white can. Corn should be full, neat, and remove too old raw materials. As the ripening process is very fast, the freezing process should be completed in the shortest possible time. The frozen corn can be frozen with ear sticks or twisted into grains. The process is as follows:

40、 remove the skin, picking tassel, in 100 degrees Celsius hot water blanching 3 4min to 10 DEG C rapid cooling after removal. Freeze from 10 to 20min in the freezing unit below -30, and freeze to be packed in plastic bag.Another method is not blanching, the green corn tassel removed, leaving 1 to 2 l

41、ayers of skin, directly frozen, refrigerated after packaging, the effect is also very good.14 spinachSelect leafy leafy foliage with luxuriant foliage. Material fresh, dark green, no yellow, no pests, the length is about 150 300mm. harvest and freezing processing interval should be as short as possi

42、ble, storage time should not exceed 24h. by primary processing to pick off the line, yellow leaves, roots of spinach to resection; cleaning by washing plant.Spinach roots and leaves of the degree of tenderness and moisture content is different, so the blanching time for roots should be longer, leave

43、s shorter. Specific methods of operation: the spinach root abluent vertically put in a basket, blanching, take root immersion in hot water blanching 30s, then all immersed in the hot water blanching 1min. in order to keep the spinach thick green, blanching after rapid cooling to 10 deg. After coolin

44、g by water spinach plants, each 500g a bundle in a plastic bag, a sealing machine sealing, and then in the low temperature of -30 DEG C 20min. after freezing frozen spinach is very brittle, easily broken, packaging should be handled with care, general every 20 bags in one carton.15 celeryRaw materia

45、ls require fresh petiole, no yellow leaves, no pests and diseases, bright green, more than 300mm long. At the beginning of processing, we should select each plant, remove all the leaves, and remove the roots. After washing, cut into an inch long segment, blanching at 100 DEG C in hot water for 1.5 2

46、min, then quickly cool down to 10 degrees celsius. After draining, into the freezing device (-30 DEG C) freezing 10min, final packing and cold storage.16 leekLeek can be processed into quick-frozen leek stuffing. Raw materials require fresh, yellow leaves, no pests and diseases. In the initial proce

47、ssing, the leaves and the roots of the leaves and the leaves of the roots should be eliminated. Wash away the sand and dirt, drain and cut into fine, quantitative packaging, 10 15min. when eating mix with meat, edible oil, salt and other accessories at -30 deg.c freezing.17 coriander (Yuan Sui)Raw m

48、aterial requirements and initial processing are the same as leeks. After washing and draining the whole plant into a plastic bag, packing quality is generally 100g, 250g, or 500g, and then placed in sealing machine sealing, direct freezing.18 garlicThe general garlic processing season in mid May, ra

49、w material fresh, no pests, no hot spots, sound is not empty, the length of 350 500mm. selected by root cut moss bud, root ministry, cleaning 2 3 times, in 100 degrees Celsius hot water blanching 1.5 2min (which needs to be carved into garlic inch section Houpiao hot) blanching, after rapid cooling

50、to 10 deg. The whole frozen garlic must be neatly packaged frozen. Cut into the fluidized bed freezers frozen garlic 10min, finally quantitative packing and cold storage.19 potatoesPotatoes can not only be made into convenience foods, but also can be made into frozen foods. As potatoes can be stored

51、 for years, therefore, the development of its products is not enough at present. In fact, the quick-frozen products of potatoes have broad prospects.Frozen potatoes by frying process, with a large, smooth, no pests of raw materials, peeled, cut into the desired shape (e.g., block, Ding, etc.), with

52、soybean oil Zhacheng gold, Lek oil, cooling, quick freezing, packing and cold storage. Refrigerate for -18 months at least 12 degrees centigrade.In addition, you can also add other raw materials to make potato cakes, potato cakes, expansion potatoes, dice potatoes and other convenience foods.20 taro

53、Taro is rich in the south, and its quick-frozen products (frozen taro fish) are sold abroad. The raw materials should be graded, washed and peeled separately according to grade and immediately immersed in water to prevent oxidation browning. In 100 degrees Celsius hot water blanching 5 10min, blanch

54、ing time depending on size, blanching after rapid cooling to 10 DEG in Lishui, freezing device (-30 DEG C) frozen, refrigerated packaging. Because taro is discolored by iron ion, iron tools are strictly forbidden in the process of processing. Different sizes of taro should be selected grading, respe

55、ctively, quick-frozen, in order to save energy consumption.21 carrotsThe carrot is a nutrient rich and easy to process vegetable. Raw materials require bright red, cross section yellow core, luster without injury. We should choose one by one cut processing, non edible part, cleaning 2 3 times, accor

56、ding to the requirements of cut into various shapes, such as bulk, sheet, strip, round shape, pattern, small pieces of sliver shaped pattern, so the general processing residual broken into ding. The products for export should be peeled off according to the requirements of the merchants, and the peeling machine can be used in mass production. Processed products into the basket, 100 degrees Celsius in hot water, blanching 1 3min., blanching degree should be strictly controlled, if the bleach is too hot, will become