Operations of the digital technological flow for storing agricultural products
The operations leading up to the preservation of agricultural products are: harvesting, conditioning, pre-drying and storage.
1. Harvesting is a complex of successive operations that are done for the purpose of gathering agricultural products and putting them in a state to be consumed for a certain period of time, either fresh or variously processed.
The products are harvested differently according to the direction of recovery taking into account that some of them continue their maturation and after harvest. In order to determine the optimal time of harvest, a number of indices are taken into consideration: shape, size, pigmentation, elasticity, seed development, tenderness, juiciness, appearance of the section, resistance to penetration, accumulation of some chemicals, intensity of aroma, taste.
The harvesting technique consists in the execution of the removal operation from the mother plant at the optimal time, so that a lower pressure is exerted on the product. Harvesting can be done manually, mechanized and mixed.
– manual harvesting is the main operation for all horticultural species (vegetables, fruits, grapes) intended for fresh consumption.
– mixed or semi-mechanized harvesting is done in order to shorten the harvest period and consists in carrying out the harvest itself manually, and the transport of workers and packaging mechanized.
– mechanized harvesting-realizes the detachment of products, their handling and loading with the help of more or less complex special devices.
Depending on the methods and processes of harvesting, it can be:
– whole harvest, used when baking from a crop is uniform
– selective or staggered harvesting, carried out in several stages.
2. The conditioning of horticultural products includes the following operations: unloading, cleaning, sorting, treatment, quality control and packaging.
Product unloading can be done in bulk in unpalletized packaging and palletized packaging. The unloading of the products transported in bulk can be done by tipping, and further they can be taken with conveyor belts or elevators.
The palletized packaging is unloaded by means of a forklift and an electrostivator, while the unpalletized packaging is unloaded by means of internal transport equipment(platform trolley, pallet truck, conveyor – elevator).
Cleaning follows both the shaking of the Earth and the removal of impurities from the surface of the products by wiping, brushing, washing with water or various aqueous solutions, after which it necessarily follows the blowing but also the removal of poorly adhered leaves or portions of the product by trimming or chiseling.
Sorting is the operation that consists in the classification of the crop according to standard criteria, namely: phytosanitary status, mechanical and biological damage, shape deviation from those specific to the Variety, the degree of maturation expressed by color and gloss. Sorting is done partially or totally during the harvest and after. When it is carried out simultaneously or immediately after harvesting it is called Presort.
Calibration is the sorting or selection of horticultural products by size and is generally done mechanized and partially manual, in which case a kit of rings or templates are used to calibrate.
Packaging is the operation that consists in arranging horticultural products in spaces delimited by walls made of different materials called packaging.
Packaging for transport and storage can be made of wood, plastic, cardboard.
Wooden packaging is represented by:
– lada type T for vegetables and fruits with hard pulp;
– lada Type D for vegetables and fruits with soft pulp;
– p-type lada with or without lid for vegetables and fruits with hard pulp;
– lada Type C, Lada type platter for perishable vegetables and fruits;
– lada Type V for vegetables su intense metabolism: greens, Leafy Vegetables;
– s-type lada similar to C-type but with larger dimensions;
– fruit pallet box, also used in the field for the transport of products.
Plastic packaging is represented: jars, baskets, glasses, alveolar trays.
Cardboard packaging are: corrugated wooden boxes and boxes.
Textile fiber packaging such as jute bags for onions, potatoes, nuts, beans.
To fix the products, as well as to isolate them between them preventing the transmission of diseases are used auxiliary materials such as: paper, paper bar, talaju, wood sawdust, and for the products to be more attractive are used: perforated cardboard boxes or without perforations, with cellophane windows, bags of stapled textile mesh, perforated polyethylene bags, plates of cellulose paste and plastic material, baskets, honeycomb trays.
Packing can be done by non-arrangement (bulk), tight packing or packing by arrangement that can be in straight rows, in chess and in eseica.
3. The preraciation of horticultural products represents the totality of the operations performed in order to remove the excess heat from the level of the orchard heat to the one at which the relevant products are kept. It is done by several methods, all based on the rapid transformation of heat from the respective products to a cooling medium represented by air, water or ice.
Proper pre-hardening or cooling can be carried out depending on the nature of the products in a variable period of time from 30 min to 24 hours and more.
The speed of pre-hardening of any product depends primarily on its accessibility to the cooling medium, the speed of movement of the cooling medium, the nature of the cooling medium.
Among the methods used for preraciation we mention:
– pre-hardening with pressed water ice;
– pre-washing with water;
– fast-moving air preraciation;
– vacuum cleaning;
Whatever the method of pre-hardening these products will be immediately put in low temperature conditions so that they do not depreciate. If the possibility of pre-hardening is missing, it is necessary that after harvesting the products concerned are not left under the influence of sunlight and under the action of wind or light. They must be placed in packages and stacked in shelters, and the introduction to storage to be done in the morning, before sunrise, because in the night The Orchard temp decreases noticeably, ensuring a natural cooling of the products.
4. The storage of horticultural products is an import operation within the process of fresh keeping of horticultural products and consists in their introduction into the storage spaces. The choice of storage method is related to the physical, chemical and physiological properties that characterize each product.
In practice, several storage methods are used, namely: bulk storage and storage in palletized and unpalletized packaging.
Bulk storage is used for products with good mechanical strength (potatoes, onions). By using this method , the storage area is fully occupied, and the handling of the product is mechanized with the help of conveyor belts.
Unloading means of transport is done by tipping in a bunker provided at the base with a conveyor belt that moves the product along the length of the bunker and then passes it on other conveyor belts placed in the waterfall.
At the end of each strip, where the product passes from one strip to another, a metal grate is mounted through which the adherent Earth falls on the products,small vegetable debris, thus achieving a metal cure through which the adherent Earth falls on the products,small vegetable debris, thus achieving a cleaning of the respective products. These nets are collected in baskets or wooden boxes placed under the grills.
Packaging storage is used for long-term storage of vegetables and fruits in refrigerated warehouses and warehouses with natural ventilation. Storage in pallet boxes consists in placing the products in packaging, in bulk up to the upper edge of the pallet box, then with the help of the forklift, the boxes are inserted into the storage cell.
Their arrangement is done according to the principle “first in – first out”.
Between the walls and the edges of the stack block and between the packaging columns, certain spaces are left to allow the circulation of air conditioning, discharged by the cooling batteries.
The storage in said use the Wooden said proper and Plateau type that are stacked palletized and unpalletized.
In order to store palletized it is necessary to perform two successive operations: arranging the packages on the pallet and stacking the palletized packages in storage spaces. The packaging arrangement on the pallet is done in columns depending on the size of the packages and the pallets used to occupy a larger area of the pallet surface.
The pallet type packages are stacked on pallets with uprights after the column system, after which the pallets are stacked on 4 levels up to 7 m height.
Unpalletized storage is done by directly stacking the packaging in the storage space. In these cases the packaging stacking is done after several packaging arrangement systems, namely: lax, compact, mixed, with vent.
The lax arrangement system consists in the arrangement of packages on top of each other in a cross shape, presenting the advantage of good air circulation inside the stack, due to the channels that result from the arrangement of packages. It is used in unused deposits and pr species that have an intense metabolism.
The compact arrangement system involves the arrangement of packages side by side without gaps between them, and vertically, also overlapping each other on a height of 2-3m. this system has the disadvantage of poor air circulation in the product layer.