① Production process: raw material selection → cleaning, peeling, slicing → mixing → drying → frying → grading and packaging.

(2) process points:

Selection of raw materials: bananas used to make banana slices should be fully mature, free from pests and diseases and rot.

Cleaning, peeling and slicing: rinse bananas in clean water, peel and cut into thin slices with a thickness of 0.5 ~1cm.

Mixing: banana 10, milk powder 1 0 and water 5. First, mix the milk powder with water, pour it into banana slices, and stir thoroughly so that all banana slices can be stuck with milk powder.

Drying: put the banana slices into a roaster, raise the temperature to 80 ~100℃, and dehydrate them. When the water content of the banana slices is16% ~18%, they can be taken out of the container.

Deep-frying: Baked banana slices are fried in130 ~150℃ plain oil until it is brown, and the crispy banana chips are obtained.

Graded packaging: Graded packaging according to color and size.

2 preserved banana

① Production process: raw material selection → classification → pre-cooking → cooling → peeling → dicing → color protection → hardening → boiling in sugar solution → soaking in sugar solution → drying → shaping → packaging → finished product.

(2) process points:

Selection and classification of raw materials: select ripe bananas with light yellow peel and soft pulp, and remove insects, tissue damage and overripe bananas. Then, the qualified raw materials are graded according to the consistency of fruit diameter and maturity, so that the quality of the prepared finished products is uniform.

Pre-cooking and cooling: put the raw materials into boiling water, add 0.1%~ 0.2% alum into the water, cook for 2 ~ 3 minutes, take it out and quickly cool it to room temperature with cold water.

Peeling and dicing: peel the banana skin by hand, remove the rotten parts, discolored spots and tendons on the surface of the pulp with a stainless steel knife, then cut it into two halves longitudinally along the middle line of the pulp, and then cross-cut it into blocks of about 5 cm.

Color protection: quickly put the pulp cut into small pieces into 2% sodium sulfite solution and soak it for 5 minutes to prevent enzymatic browning and make the pulp turn from light yellow to black.

Hardening: put the color-protected fruit block in1.5% calcium chloride solution and soak it for 5 ~ 8 minutes. The soaking time and the concentration of calcium chloride solution can be properly adjusted according to the maturity of raw materials to increase the hardness of pulp and facilitate processing.

Solution boiling and soaking: 55% sugar solution is prepared, and a certain amount of methyl cellulose (CMC) is added to the sugar solution, and the concentration of CMC is controlled at about 0.5%. After the sugar solution is boiled, pour it into the fruit pieces, cook until the sugar content rises to 60% ~ 65%, turn off the fire and stop cooking, and soak the fruit pieces in the boiled sugar solution for about 24 hours.

Drying: drain the sugar solution of the fruit block and dry it in a far infrared oven at 65℃ for about 8 ~10 hour until the surface of the fruit block is not sticky.

Shaping and packaging: the finished products with different colors are removed and shaped into a unified shape. Then vacuum sealed packaging is carried out with polyethylene plastic bags with poor air permeability.

③ Product quality requirements: smooth appearance; Non-sticky, full tissue, uniform sugar penetration; High sweetness, rich banana flavor, no astringency, bitterness and other strange smells.

The finished product contains 20% water and 60% ~ 65% total sugar.

Canned banana slices

There are some difficulties in canning bananas: (1) After canning, bananas tend to be soft and rotten, lose their shape, and can't keep the shape neat; (2) The secretion of causal glue makes the surface of the product sticky; (3) The sugar solution in the jar is unclear and is milky; (4) It is difficult to keep its color, fragrance and taste unchanged. The above problems are related to the selection of raw materials, production technology and technology of bananas.

There are several methods for canning bananas: direct canning, vacuum treatment, assimilation by adding calcium chloride, pectin extraction and so on. Pectin extraction method is to add boiling sugar solution before sealing to extract pectin from bananas, so that banana slices are complete and the tank liquid is transparent. This method meets the requirements of canning and is an ideal production method at present.

The process flow is banana → heating → peeling → slicing → sugar solution → soaking → heat treatment → canning → injecting sugar solution → exhausting → sealing → sterilization → cooling → packaging.

Production method 1. Selection of raw materials: the maturity of bananas has a great relationship with the quality of canned food. Bananas are not hot enough and have a sour taste; Overripe, easy to be soft and rotten, resulting in irregular shape and unclear liquid. Nine ripe bananas are ripened by chemical method (calcium carbide method or ethyl acetate method) or smoking method at room temperature 18℃ until the third or fourth day, which is the best raw material for canning. At this time, the banana peel is yellow, with small black spots of plum blossoms. Or ripening until the sour taste just disappears on the same day or the next day for processing.

2. Peel and remove the silk: when the banana is ripe properly, take it out and rinse it with sterilized water. Then peel off the skin, and then use the tip of a stainless steel knife or a bamboo clip to pick out or clip the silk around the pulp. It must be carefully removed, otherwise, after being canned, the banana slices will turn brown into brown coarse fibers around them, which will affect the quality and appearance.

3. Slicing and dipping: remove the clean pulp by winding, and cut it into banana slices with a thickness of 1 cm with a stainless steel knife or slicer. Immediately after slicing, it should be dipped in 50% sugar solution and not dipped for 20 minutes at room temperature to prevent the pulp from oxidation and blackening.

4. Heat treatment: take out the soaked banana slices with a hollow aluminum spoon, put them in 30% concentration boiling sugar solution, and keep them at 85 ~ 95℃ for 10 minute.

5. canning: (1) mixing sugar juice; Pour 35 kilograms of clear water into a pot and heat it to a boil, then pour in white sugar 15 kilograms and stir it until the sugar is completely dissolved. Measure the sugar content with a refractometer and correct it to 30%. Add 0.5% citric acid to the sugar solution and add 35 mg of vitamin C to each can. After filtering, keep the sugar solution warm for later use (keep it above 80℃).

(2) Washing bottles: the bottles should be washed with clear water and sterilized by steam (100℃ for 20 minutes). The apron can only be used after being boiled in water for 5 minutes.

(3) Canning and weighing: 500g Shengli bottles are used, and each bottle accurately weighs 300g banana pulp and 205g sugar water, with a total net weight of 505g. Including vitamin C35 mg (adding a little vitamin can also make the product color good).

6. Venting: The canned food filled with sugar juice should be vented in time. The venting temperature is 90 ~ 95℃ for10 ~12 minutes. When the center temperature is above 95℃, it should be sealed immediately.

7. Sealing: sealing with semi-automatic can sealing machine. After sealing, the sealing inspection shall be carried out on the inspection platform, and the unqualified real cans shall be removed in time for rework.

8. Sterilization and cooling: after 30 minutes, stop heating when the water temperature in the sterilization tank reaches 100℃. Cooling in three stages, and taking out when the temperature of the tank body is 35 ~ 38℃. Wipe the can with gauze after cooling to prevent the can cover from rusting. Sterilization formula 7'-30'-5'/ 100℃