The processing method of preserved pineapple is as follows:
1. Selection and treatment of raw materials: It is best to choose green ripe fruits with disease-free and insect-free maturity of 80%, wash them with tap water twice, then peel them with a stainless steel knife and cut them into 2cm× 2cm pieces or 2cm× 5cm strips for later use.
2. Sugar-stained sugar bubble: put the cut pineapple strips or blocks into a stainless steel pot vessel, add 30% sugar and mix well for 6- 12 hours. Then pour the fruit and liquid into a boiling pot, boil for 1 hour, and then cool naturally. After cooling, standing at normal pressure and soaking in sugar 12 hours.
3. Drain and dry pineapple fruit: take out the fruit stained with sugar with a stainless steel net spoon, drain the sugar solution, pour it on a drying tray, put it in a drying oven, stop heating when the water content of the fruit reaches about 28%, take out the fruit and naturally cool it.
4. Packaging and warehousing: packaging in edible plastic bags, sealing and warehousing to make preserved pineapple.
5. Note: (1) Pineapple is rich in fiber and acid. The crispness of preserved fruit is related to the time of sugar pickling. The results showed that the best curing time was 60 minutes, and the finished preserved fruit had good crispness, moderate sweetness and sourness, golden color and good transparency. (2) The sugar content of preserved fruit should reach a certain height to ensure the quality of finished products. When the sugar content reaches more than 65%, the shelf life of preserved pineapple can reach more than half a year under natural conditions. However, the current consumption concept tends to be low-sugar, low-fat and health food.
Manufacture of preserved strawberry
Preserved fruit made of strawberries has the nutrition and flavor of strawberries, and is moderate in hardness, sweet and sour, easy to digest, and has the effects of stimulating appetite, strengthening spleen, nourishing and strengthening body. It is a kind of health food with great development prospect.
process flow
Strawberry pulp residue → beating → concentration → baking → peeling → plastic packaging → inspection → finished product.
Key points of operation
1. Select fresh strawberries with water content below 30% for beating, remove impurities such as dead leaves and rotten fruits from the pulp, beat them into fine pulp with colloid mill or beater, knead them by hand until there is no obvious graininess, and then put them into storage tank for later use.
2. Concentration Put strawberry pulp into a jacketed pot, add a proper amount of starch aqueous solution, stir quickly and evenly to prevent caking and precipitation, and then heat and concentrate. In the process of concentration, appropriate amount of white sugar, citric acid and preservative should be added, stirred evenly, heated and concentrated, and the pulp can be taken out of the pot after thickening.
3. Casting and baking: pour the concentrated fruit pulp into a clean stainless steel plate and shake it evenly on the platform (about three or four millimeters thick). After that, it is baked in an oven or a curing barn, and the temperature is controlled at about 80℃ for about 8 hours to 10 hour until it is not sticky, soft or hard.
4. Uncover the skin and lay the dried preserved fruit flat on the platform. When it is hot, use a stainless steel knife to separate the whole preserved pulp from the plate and cool it quickly (you can use an electric fan in summer and ice cubes in winter).
5. The cooled preserved fruit is shaped and packaged into strips, barrels and blocks. Use cellophane according to specifications 30g, 50g, 75g, 100g, etc. , and then vacuum packed with transparent composite bags or aluminum foil bags, packaged and sold, or stored at 65438 00℃ and relative humidity less than 70%.
Processing technology of preserved grapes
Grapes, besides being eaten directly, are mostly used in the production of traditional foods such as wine making or sun drying. Combined with the characteristics of grape fruit, preserved grape fruit was developed. As a new type of food, preserved grapes are not only much cheaper than raisins, but also delicious. After tasting and identification, they are deeply loved by consumers. 1. Process raw materials → selection → pruning → leaching → picking → sorting → blanching → sugar making → baking → softening → powder mixing → classification → packaging → finished product 2. Key points of technology 1 Raw materials require grapes to have high maturity, which can be picked between nine ripe and full ripe. It is best to choose a variety with light color. 2. Raw material treatment (1): After removing rotten grains, cut the ear into spikelets with scissors, then rinse with running water for 2-3 minutes, soak in 0.05% KMnO4 solution for 3-5 minutes, and finally rinse with clean water for 2-3 times until the water is not red. (2) Selection and classification: When selecting grains, be careful not to break them, and at the same time, select and remove rotten, diseased and undersized immature grains. (3) blanching: blanch the selected grape grains with boiling water for 1 ~ 2 minutes, and then immediately put them in cold water for cooling. 3. The preparation of sugar is completed in two steps. (1) sugar stain: add 25 ~ 35 kilograms of white sugar to every 50 kilograms of grapes, pickle the fruit layer by layer, and finally wrap a layer of sugar on the surface of the fruit. After 24 hours of sugar pickling, filter the sugar solution into the pot, add 10 kg white sugar, boil and dissolve it, pour it into the fruit, and continue sugar pickling for 24 hours. (2) sugar soaking: filtering out the sugar solution of the sugar-stained grapes, pouring it into a pot for heating, adding 10 kg of white sugar, stopping heating in a boiling well after melting, pouring the grapes, soaking for 4-6 hours, taking out, adding 10 kg of white sugar into the sugar solution, boiling and dissolving, adding a proper amount of citric acid, keeping the sugar solution containing a proper amount of reducing sugar, and pouring out the grapes soaked with sugar. In a word, the sugar making of preserved grapes is the process of putting grapes into the gradually enriched sugar solution for sugar infiltration, which can not be cooked with the sugar solution in general. 1 ~ 2 days later, it can be seen that the glucose content is sufficient and becomes transparent. 4. Bake the preserved grapes twice, paying attention to ventilation, dehumidification and inverted plate setting. (1) Baking temperature: When baking for the first time, gently take out the grapes, drain the sugar solution, spread it on a tray, and send it to a baking room for baking at 60-65℃ for 6-8 hours. When the water content in the grapes is reduced to 34-26%, the grapes are taken out of the baking tray, and the grapes are properly humidified and shaped for the second time. The second baking temperature is controlled at 55 ~ 60℃ for about 4 ~ 6 hours. When the water content drops to about 65,438+08% and the product does not stick to hands, you can take it out of the room. (2) Ventilation and dehumidification: Pay attention to ventilation and dehumidification during baking. The method and time of ventilation and dehumidification can be determined according to the relative humidity in the drying room and the magnitude of external wind. When the relative humidity in the drying room is higher than 70%, ventilation and dehumidification should be carried out. If the indoor humidity is very high and the external wind is very low, you can turn on the ventilation window and dehumidifying pipes. If the indoor humidity is high and the external wind is strong, the air burst window and the exhaust pipe can be opened alternately. Generally, it is ventilated and dehumidified for 3 ~ 4 times, and the suitable time for each time is about 15 minutes. Ventilation and dehumidification, if instructed by meta-meter, can also be carried out by experience. According to experience, when people enter the drying room, if they feel the air is humid and sultry, their faces will feel wet. When respiratory distress occurs, ventilation and dehumidification should be carried out; When the air in the drying room is dry. There is no feeling of wetness on the face. When breathing is smooth, you can stop discharging moisture and continue drying. (3) Traying: In the process of baking preserved grapes, we should pay attention to changing the position of the baking tray and turning the fruits in the tray. Usually, pouring is carried out at the end of the first baking. Combined with juice pouring, the fruit can be properly rubbed into a round or oblate shape by hand. 5. Put the softened baked goods indoors, regain moisture for half a day to one day, remove unqualified products such as black spots or black and broken preserved fruits, and mix the qualified products with powder. Grinding glucose and citric acid into fine powder respectively, and mixing them evenly according to the ratio of 40:l, so that the rejuvenated preserved grapes are rolled in the powder, air-dried for half a day and then packaged. In addition, because different grape varieties have different acidity, the amount of citric acid in the powder can be appropriately increased or decreased according to different tastes of people. 6. The finished products are packed in plastic bags with the trademark of Du Yuan, with different quantitative packages such as100g, 200g and 250g, and stored in a cool and dry place in a sealed way. Iii. Product quality requirements 1. Sensory index color: bright and transparent, showing a deeper color than the original fruit; Form: soft, full of sugar, not sticky; Taste: delicious, maintaining the original grape taste, sweet and sour after mixing powder, no odor. 2. Physical and chemical indexes show that the sugar content is 65-68%, the water content 16- 18%, and the heavy metal content meets the national standards. 3. Health indicators have no signs of corruption caused by pathogenic bacteria and microorganisms, and meet the food hygiene standards stipulated by the state. Four. Precautions 1. When making sugar, master the appropriate reducing sugar content in sugar solution, the appropriate reducing sugar content and the region and environment. Climate conditions and other factors, in high temperature and high humidity areas, the reducing sugar content can be less, while in low temperature and dry areas, the reducing sugar content can be controlled higher, generally around 50%. To adjust the reducing sugar content, invert sugar solution or sugar solution with excessive invert sugar can be added. Remember not to soak the fruit when the pH value is too low, otherwise it will easily lead to browning. 2. Hardening treatment In order to prevent grape fruit from being broken, it can be hardened before sugar making, that is, soaked in 0. 1% CaCl2 solution or treated with 3 ~ 5% lime water supernatant, but after treatment, the residual CaC 12 or lime should be washed.