MODES OF PRODUCTION SMALL CORN FLAKES IN SEMI-INDUSTRIAL CONDITIONS

Abstract

The article presents study results of steaming and tempering modes effect on the yield and quality of small corn flakes. Production of small corn flakes was carried out in semi-production conditions on the basis of a test section of the existing machinebuilding operation OLIS Llc, which allowed to get as close as possible to the production conditions. The study consisted of 2 series of experiments: in the first series of experiments, five identical samples of corn grit with an initial moisture content of 13.1% were sent to the steaming stage, where it was subjected to water-heat treatment for a specified period of time (2.5; 5; 7.5, 10 and 12.5 minutes), with increasing steaming time, the tempering time gradually increased by 10 minutes, from 10 to 50 minutes, respectively. In the second series of experiments, the grit was moistened by cold conditioning to a predetermined moisture content of 16±0.25%, moistened for 12 hours, and then moistened grit was subjected to water-heat treatment at the same parameters as in the first series. The initial sample of corn grit No. 4 was obtained in the factory and had the following quality indicators: moisture content – 13.1%; ash content – 0.58%; the starch content – 71.1%. The technological scheme of small corn flakes production in semi-production conditions included the following steps: grit moistening by a special device that sprays water for 15-20 seconds, and wetting in special sealed containers of grit samples (if necessary); grit steaming in the steamer camera of periodic action of EPP-1; tempering for 10-50 minutes in thermostable conditions; flattening of the obtained product on a rolling mill "EVV-1" with smooth rollers at a gap of 0.3-0.4 mm; drying the flattened product on a laboratory dryer; control on the laboratory dispenser RLU-1 (sieving on a sieve No. 067) for extraction of flour products. It was found that as a result of grit steaming with initial moisture content (13.1%) and subsequent flattening in semiproduction conditions a lot of meal was formed – 33.6 and 23.3% with the duration of steaming for 2.5 and 12.5 minutes, respectively, with an ash content of 0.64-0.57% and a starch content of 63.2-63.4%. With the ash content of the original grit of 0.63% and the starch content of 71.1%, it indicated that although moisture penetrated into the inner layers of the grit during conditioning, yet it was not enough on the surface. Therefore, high-ash peripheral grit particles were worse exposed to flattening, crushed and formed meal. Thus, the selected modes of small corn flakes production in semi-production conditions were not sufficient to provide the grit particle with the necessary structural and mechanical changes, and further increase in the duration of processing was impractical, as it significantly increased energy consumption and reduced flakes production productivity. Preliminary wetting of grit to a moisture content of 16±0.25% and subsequent steaming at the same parameters as grit flakes with a starting moisture content of 13.1% showed a significant decrease of flour products output, which amounted to 13.7-7.8% at 2.5 and 12.5 min of steaming, respectively. However, the additional grit moistening before steaming led to an increase in flakes moisture content, which requires higher energy consumption during their drying and bringing them to standards (less than 13.0%), guaranteeing their storage for 6-9 months. The technologically appropriate wet-heat processing mode of corn grit in the production process of flakes in semi-production conditions, to obtain small corn flakes according to the scheme of preliminary wetting of grit, steaming it in a steamer of periodic action, short-term tempering, flattening, drying and control of flakes on meal separation, is a grit moisture content before steaming at 16±2.5%, steaming at atmospheric conditions for 7.5-10 min, duration of tempering – 30-40 min. The obtained flakes do not require cooking, but can be brewed in boiling water for 4-5 minutes.