chemical opening
1. oxalic acid opening: pine nuts are heated and soaked in cold water at zero degree, and liquid oxalic acid is added to the water, which is generally used for rust removal.
2. Citric acid opening: Citric acid is a food additive, but although it is not directly harmful to human body, it can promote the excretion and deposition of calcium in the body. If you eat food containing citric acid for a long time, it may lead to hypocalcemia. Children show nervous system instability, excitability and autonomic nerve disorder; Adults suffer from hand and foot convulsions, muscle spasms, paresthesia, itching and digestive tract symptoms.
Manual opening
The opening method is a self-made opening machine. Workers are skilled in using their left and right hands alternately to add hands and feet. They loosen the nuts one by one and pedal with their feet. The design angle of the machine is just right, and the pine nuts don't break, and it doesn't hurt their fingers just after opening. It is because of this method that we can tell the difference from chemical opening, and the artificial open pine has a pressure point, which can be seen at a glance if it is not obvious alone.