How to prepare tomatoes for canning
How to prepare tomatoes for canning? Crushing is carried out simultaneously with the separation of seeds on crushers, seed separators type KOS. Seeds that have not undergone heat treatment can be used as a seed.
The crushed tomato mass is collected in the receiving tank and the ANV-120 pump is fed to a coarse rub on a rubbing machine of the type T1-KP2U or RZ-KIZ .00.000-01 equipped with sieves with a hole diameter of 5 mm.
In the process of so-called cold wiping, the stems that inlay the parts of the fruit are removed, consisting of the fiber of pentosans, lignin and other substances giving hardness to the raw material. Due to this mechanical separation of the peel, which is 2-3 times more in small-fruited tomatoes than in the conventional manual collection material, it is possible to obtain a tomato mass with a reduced amount of insoluble solids and thereby normalize the further process of concentration.
Heated pulp.Coarse pulp obtained at the enterprise or delivered from primary processing facilities is heated up to 75 ± 5 ° С in A9-KMB tubular heat exchangers in order to convert insoluble protopectin to soluble pectin, as a result of which separation of seeds and peel is facilitated during subsequent wiping and decreases to 3 times the amount of waste. At the same time, heating, inactivating the enzymes that destroy pectin, contributes to its preservation, which gives the product a uniform consistency.
At the same time, air is removed from the product particles, which contributes to the preservation of vitamin C and other nutrients of tomatoes.
The pulp delivered to the plant is wiped, heated and cooled after storage is also heated to 75 ± 5 ° С.
Wiping the pulp. The separation of the skin, seeds and vascular fibers is completed on a wiper with a hole diameter of 1.2 mm. To obtain a uniform consistency and fine grinding, the mass is subjected to finishing through sieves with openings with a diameter of 0.4 mm. The rubbing mode is adjusted by changing the gap between the whips. cleaning machines and sieves from 4 to 16 mm and a pitch advance angle of up to 7 °.
The rubbed pulp-semifinished product after heating is subjected only to finishing.
To remove sand, it is recommended to pass the finished mass through hydrocyclones, they allow reducing the amount of it in the pulp by 10 times.
Waste from the wiping machines are sent for steam digestion at 96 ± 2 ° C into screw or other types of apparatus. They first arrive at the VSSSH stacker for separating the liquid part, juice, by gravity, and then to the PNDYA screw press for spinning. Humidity of waste after pressing should not exceed 65 ± 3%.