Gelatinisation

The gelatinisation process of the rice flours aims to modify their technological properties, inducing a molecular restructuring of the starchy component. In order to efficiently gelatinise the rice starches, two key elements are required: water and energy.

The technology adopted to apply this kind of modification consists of a device with a 600 kg/h productive capacity. At the beginning, a pre-conditioner enters into function; this can be described as a tank longitudinally divided in two communicating chambers to form a serpentine trend; within the chambers there are some shafts provided with vanes with a profile similar to the spires of a worm transport. Their purpose is to completely mix the flours and water and to advance the mixture that is progressively forming. Through a series of atomizer nozzles in the upper part of the device, steam and water are added to the raw material, providing the thermal energy and humidity necessary to obtain the gelatinisation level desired. At the discharge exit of the device, the mixture is alimented in the press below by fall, where a couple of co-rotating worms applies an ironing and cutting action, which guarantees the complete homogeneity of the humidity levels within the mass.

At the exit from the twin screw press, there will be a warm and damp mass made of starchy substratum with a specific gelatinisation level, according to the setting of the different variables (temperature of   steam, the dough humid tenor, retention time, etc.); this mixture is then adjusted to humidity and temperature levels suitable to its long preservation. The final mixture passes through a device with a grilled bottom to reduce it to a series of flakes.

From this stage, again by fall, the flakes enter a rotative drier, in which a hot air depression system applies the drying convectional process against the stream on the flakes. Once they are out of the drier, the flakes, now dried and cooled, enter the reduction system, made of a series of rolling mills, to produce a flour of the desired granulometry. Finally, the product obtained is transferred through a pneumatic transport to the packaging stage, packed in big bags or in 25 kg paper bags.