Processing technology of potato powder: raw potato → selection → cleaning → peeling → slicing → cooking → adjustment → drying → screening → inspection → packaging. The key points of operation are as follows.
(1) The choice of raw materials directly affects the quality of finished products. There are obvious differences in dry matter content, color in potato, depth of bud eye, reducing sugar content, solanine content and polyphenol oxidase content among different varieties of potato. The higher the dry matter content, the higher the powder output; If the potato meat is white, the finished product is light in color; The more and deeper the bud eyes, the lower the yield; The content of reducing sugar is high, and the color of the finished product is dark; The content of solanine is high, it is difficult to remove toxins and the process is complicated; High polyphenol oxidase content and serious browning of semi-finished products will lead to dark color of finished products. Therefore, we must choose varieties with shallow buds, good potato shape, white potato meat, low reducing sugar content and low solanine content to produce potato whole powder. The selected raw materials are sent to the hopper, weighed by a belt conveyor, and selected at the same time to remove the potato pieces with mildew spots and rotten chips.
(2) Wash the washed potatoes with a dry cleaner to remove sand and impurities, and then send them to a drum cleaner for cleaning.
(3) Put the peeled and washed potatoes into a steam peeler in batches, heat them for 20s under the pressure of 5 MPa ~ 6 MPa, so that blisters appear on the potato surface, and then wash the skins with running water. Steam peeling has no strict requirements on the shape of raw materials. Steam can uniformly act on the whole potato surface, and the skin layer with a thickness of about 0.5 mm ~ 1 mm can be removed. Attention should be paid to prevent enzymatic browning caused by polyphenol oxidase during peeling. Browning inhibitor (such as sulfite) can be added and then rinsed with clean water.
(4) Sliced peeled potatoes are cut into 8mm ~ 10mm slices with a slicer (too thin potato chips will affect the flavor of finished products and increase the loss of dry matter), and attention should be paid to prevent enzymatic browning when slicing.
(5) The purpose of pre-cooking, cooking and crushing cooking is to ripen potatoes to fix starch chains. Pre-boiling at 68℃ for 65438 05 minutes, and then cooking at 65438 000℃ for 65438 05 minutes to 20 minutes; After that, the cooked potato pieces are divided into small particles in a blender, and the particle size is 0.15 mm ~ 0.25 mm ~ 0.25 mm..
(6) adjusting the temperature of potato granules in the fluidized bed to 60-80 DEG C until the starch is cooked. Free starch should be reduced to 1.5% ~ 2.0% as much as possible to keep the original flavor and taste of the product.
(7) drying the sieved potato granules in a fluidized bed, wherein the drying temperature is inlet140 DEG C, the outlet is 60 DEG C, and the moisture content is controlled at 6%-8%; After the materials are screened by the screening machine, the finished products are sent to the finished product room for storage, and the materials that do not meet the particle size requirements are transported to the mixer through pipelines for repeated processing.
(8) After the potato powder in the finished product packaging room is packaged by an automatic packaging machine, the finished product is sent to the finished product warehouse for sale or made into a series of products.
Using whole powder as raw material, through scientific formula and adding corresponding nutrients, convenient foods with rich nutrition, varieties and flavors can be made, such as snowflake breakfast porridge, meat rolls, biscuits, milk potato powder, patties, meatballs, jiaozi, crispy magic tablets and so on. Can also be made into cold drinks, convenience foods, puffed foods and special people (hyperlipidemia, diabetes, crispy magic tablets, etc. ).
2. Fried potato chips technology
The technological process of fried potato chips is as follows: mashed potatoes and corn flour are mixed → flour blending → gelatinization → seasoning → cooling → ripening → slicing → drying → frying → deoiling → packaging → finished products. The basic formula of fried potato chips is: fresh mashed potato 75%, corn starch 15%, cassava flour 3%, salt 1%, sugar 5%, monosodium glutamate 0.5%, Chili powder 0.5%, and palm oil is used for frying. The key points of operation technology are as follows.
(1) and batter mashed potatoes are used as semi-finished products, corn flour is added for mixing, various raw materials are weighed according to the designed formula, mixed evenly to make wet dough, and then put into a steamer for gelatinization at 58℃ ~ 65℃ for 20min.
(2) seasoning and mixing. After the steamed dough is cooled, the weighed monosodium glutamate, pepper powder, Chili powder, onion powder or fresh chopped green onion are respectively poured into the dough for seasoning, so as to make wet blanks with different tastes, and then further kneaded into flour columns with a diameter of 2-4 cm. The seasoning operation can also be carried out after frying and deoiling.
(3) cooling treatment: the noodle column is put into a plastic bag, sealed, and put into a refrigerator for cooling. The cooling condition is 4℃ ~ 6℃ for 5h ~11h, and the specific processing time depends on the dough size and cooling speed.
(4) Slice drying: the fully aged noodle column is cut into slices with the thickness of 65438±0.5mm ~ 2.0 mai, put into a dryer, and dried for 4 ~ 5 hours at the temperature of 4 ~ 5 hours at 50℃ to reduce the moisture content in the dry blank to 4% ~ 9%.
(5) frying palm oil at 180℃ ~ 190℃ to obtain the finished product.
With potato as raw material, more than 2000 kinds of products can be processed and produced, which are widely used in food, feed, medicine, chemical industry, textile, petroleum, casting, paper making, coating and other industries. The development and application prospect of potato and potato starch is very broad.