① Production technology: raw material selection → cleaning, peeling, slicing → mixing → drying → frying → graded packaging.

(2) Process key points:

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

Cleaning, peeling and slicing: banana is cleaned with clear water, peeled and cut into thin slices with a thickness of 0.5 ~ 1 cm.

Mixing: banana 10, milk powder 1, water 5. First, mix milk powder with water, pour in banana slices, and stir well so that all banana slices can be stuck with milk powder.

Drying: put banana slices into a roaster, and heat them to 80 ~ 100℃ for dehydration. When the moisture content of banana slices is 16% ~ 18%, they can be taken out of the container.

Deep-frying: Baked banana slices are fried in vegetable oil at 130 ~ 150℃ until brown, and crispy "banana slices" are taken out of the pan.

Graded packaging: Graded packaging according to color and size.

2 preserved bananas

① Production technology: raw material selection → classification → precooking → cooling → peeling → dicing → color protection → hardening → boiling of sugar solution → soaking of sugar solution → drying → setting → packaging → finished product.

(2) Process key points:

Selection and classification of raw materials: select mature bananas with light yellow skin 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 finished product is uniform.

Pre-boiling and cooling: put the raw materials into boiling water, add 0. 1% ~ 0.2% alum, cook for 2 ~ 3 minutes, take them out and quickly cool them to room temperature with cold water.

Peel and cut into pieces: peel the banana peel by hand, remove the rotten parts, discoloration points and tendons on the surface of the pulp with a stainless steel knife, then cut it in half longitudinally along the midline of the pulp, and then cut it into pieces about 5 cm horizontally.

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

Hardening: soak the color-protected fruit blocks in 1.5% calcium chloride solution 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.

Stereotype packaging: take out the finished products with different colors and shape them 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 odors.

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 their shape neat; (2) The secretion of causal gum makes the product surface sticky; (3) The sugar solution in the tank is unclear and milky white; (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, etc. Pectin extraction method is to add boiled sugar solution before sealing to extract pectin from bananas, so that banana slices are complete and the tank solution is transparent. This method meets the requirements of canning and is an ideal production method at present.

The technological process is banana → heating → peeling → slicing → sugar water → soaking → heat treatment → canning → sugar water injection → exhaust → 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 spicy enough and sour; Overripe, soft and rotten, resulting in irregular shape and unclear liquid. Nine-ripe bananas are ripened by chemical method (calcium carbide method or ethylene method) or smoking method at room temperature of about 65438 08℃ until the third or fourth day, which is the best raw material for canning. At this time, the banana skin is yellow and there are small black spots of plum blossoms. Or ripen until that sour taste just disappears or proces the next day.

2. Peel and remove silk: When bananas are properly ripe, take them out and rinse them with sterile water. Then peel off the skin, and then pick out or clamp the silk around the pulp with the tip of a stainless steel knife or bamboo clip. Be careful to remove them, otherwise the banana slices will turn into brown coarse fibers after canning, which will affect the quality and appearance.

3. Slicing and dipping in juice: winding to remove clean pulp, and cutting into banana slices with a thickness of 1 cm with a stainless steel knife or slicer. Soak in 50% sugar solution immediately after slicing, and don't soak at room temperature for 20 minutes to prevent the pulp from oxidation and blackening.

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

5. canning: (1) adding sugar juice; Pour 35 kg of clean water into the pot and heat it until it boils, then pour 15 kg of white sugar and stir 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 (keep it above 80℃).

(2) Bottle washing: Wash bottles with clear water and steam sterilize (100℃ for 20 minutes). The apron can only be used after boiling 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 color of the product better).

6. Exhaust: The canned food filled with sugar juice should be exhausted in time. The exhaust temperature shall be 90 ~ 95℃ for 10 ~ 12 minutes. When the center temperature is higher than 95℃, it should be sealed immediately.

7. Sealing: sealing with semi-automatic can sealing machine. After sealing, the sealing inspection should be carried out on the inspection platform, and the unqualified real cans should be eliminated and reworked in time.

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

9. Finished product packaging: According to the operating rules of finished product packaging.