How Potato Chips and Puffed Potato Products Are Made
1. Potato chips
(1) Production process: Potatoes → sorting → washing → slicing → color protection → dehydration → vacuum frying → de-oiling → cooling → sorting → packaging → finished product.
(2) Key production points ① Slicing and color protection. Because potatoes are rich in starch and have a high solids content, the slice thickness should not exceed 2mm. After slicing, starch quickly exudes onto the surface of the potato slices, and browning occurs if they are left in the air too long, so they should be immediately placed in 98°C hot water for 2min-3min; after removing them, cool them, drain off the water, and they are ready for frying. ② Dehydration. The equipment that can be used to remove surface moisture from the potato chips includes perforated rotary drums, rubber sponge squeeze rollers and centrifugal separators. ③ Vacuum frying. The vacuum frying system includes a working section and an auxiliary section. The working section mainly completes the vacuum frying process, including the frying tank, storage tank, vacuum system, heating section, etc. The auxiliary section mainly completes processes such as adding oil, discharging waste oil, and cleaning containers and pipes (including the oil storage tank and lye tank). During vacuum frying, first inject edible oil to 1/3 of the volume of the oil storage tank, heat it to 95°C, place the basket holding the potato chips into the frying tank, and lock the tank lid. After closing the vacuum valve of the storage tank, evacuate the frying tank, open the oil line connecting valve between the two tanks, and the oil is pressed from the storage tank into the frying tank; close the oil line connecting valve, heat, and keep the oil temperature at 90°C. Within 5min, raise the vacuum degree to 86.7kPa, and within 10min raise the vacuum degree to 93.3kPa. During this process, a large amount of foam can be seen being produced, and the potato chips float up. The vacuum degree can be controlled according to the actual situation, as long as "bumping" does not occur. When the foam has basically disappeared and the oil temperature begins to rise, heating can be stopped. Then separate the potato chips from the oil layer; while maintaining the frying vacuum degree, open the oil line connecting valve, and under gravity all the oil in the frying tank flows back into the storage tank. Then close the vacuum valves of each tank body and shut down the vacuum pump. Finally, slowly open the valve connecting the frying tank to the atmosphere so that the pressure in the tank matches atmospheric pressure. ④ Centrifugal de-oiling. While hot, place the potato chips in a centrifuge and centrifuge for 6min at 1200r/min. ⑤ Grading and packaging. Bag and seal the product according to shape and color conditions. Vacuum nitrogen-flush packaging is best, keeping the moisture content of the finished product at about 3% to ensure quality.
2. Puffed potatoes
(1) Production process: Potatoes → washing → peeling → trimming → dicing or cutting into strips → sulfuration treatment → precooking → cooling → drying → puffing → seasoning → packaging → finished product.
(2) Key production points ① Peeling. Either mechanical friction peeling or lye peeling may be used. ② Forming. Cut into dice, strips or other shapes according to product requirements. ③ Drying. The moisture content of the raw material should be strictly controlled. When the moisture content of the raw material drops to 28%-35%, drying can be stopped. ④ Puffing. Use airflow-type puffing equipment. After puffing, the moisture content of the material is 6%-7%. ⑤ Seasoning. The puffed potatoes should be seasoned in a timely manner into various flavors such as savory, salty and sweet.
(3) Product characteristics: The finished puffed potato chips are crispy and delicious, with a unique flavor, highly palatable and easy to store.