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Pleurotus ostreatus has been one of the most widely cultivated and the largest edible fungi in China. Global production has been growing rapidly, due to simple cultivation, low cost, quick effect, high yield, and short cycle. According to the statistics of the China Edible Mushroom Association, the output of Pleurotus ostreatus in 2020 was 6.8647 million tons, accounting for 17.45% of the total output of edible fungi, indicating the third-largest cultivar in China. However, there is still a great challenge on the efficiency and stability in the current production of oyster mushroom cobs combined with the induction, sterilization, and fermentation of Pleurotus ostreatus cultivation material and the central-hole inoculation. Taking a corncob particle as the Pleurotus ostreatus fermentation material, this study aims to develop a strain charging and inoculating machine, particularly for the higher efficiency of single machine operation, high stability, and full automation. Three devices were mainly composed of a charger, a nest, and an inoculation device. The key components of the whole machine were designed, according to the requirements of the charging quality and inoculation amount in the production of bacterial sticks, thereby determining the structural parameters of the charging auger, the socket groove cam, and the inoculation cam. A response surface method was used to optimize the test factors, where the diameter of the auger and the pitch of the auger were the influencing factors, and the charging productivity and density were the response indicators. A regression mathematical model was established for the charging productivity and density. The response value of the rotation speed of the auger was obtained to determine the most significant impact. Furthermore, the inoculum amount of bacteria was measured under different inoculation electromechanical speeds. As such, the inoculum amount was 132.33 g, and the inoculation variation coefficient was 1.19 %, when the inoculation motor speed was 120 r/min, which satisfied the number of bacteria in the center hole of the fermented material. The production requirement was measured to be 242.5 mm less than 5% of the charge and the average inoculation depth of the inoculation unit. Multi-objective optimization of the regression model was carried out to further verify the charging performance of the equipment. The optimal structural parameters of the charging device were obtained as follows: the auger rotation speed of 191.94 r/min, auger diameter 133.22 mm, auger pitch 100.00 mm, while the charging productivity was 723 bags/h, the charging density was 537.27 kg/m³, and the charging mass was 2.42 kg. The optimized all-in-one and stand-alone machine was verified for production. It was found that the charging productivity of the all-in-one machine was 726 bags/h, the charging density was 536.25 kg/m³, the coefficient of variation of the charging quality was 0.82%, and the coefficient of variation of the inoculation amount was 0.92%, the coefficient of variation of the inoculation depth was 1.05%, the mouth of the fungus bag was firm and flat, while the folds were uniform, and the nest has no leaking bags. This key component can fully meet the equipment demand for the mechanized production of oyster mushroom fermentation materials in northern regions. [ABSTRACT FROM AUTHOR]

China is the largest producer and exporter of Lentinus edodes in the world. To improve its market value, twin-screw extrusion and expansion machine has been developed to further process the Lentinus edodes. To resolve the problems of blockage, low prematurity and missing operation parameters of this machine in producing Lentinus edodes pufferent, we presented an improved twin-screw extrusion and expansion machine in this paper to lower puffer ability, improve water absorption and reduce its hardness. The equipment consists of a frame, a mixing device, a feeding device, a tempering device, a heating device, an extruding and bulking device and a rotary cutting device. It is equipped with a cooling system, a lubricating system, a transmission system, a control system and a pressure detection system. Design and determination of the anti-blocking device for the feed mixing device, the pre-maturing and tempering device, and the structural parameters of the twin screw were conducted. In order to investigate the influence of operation parameters on swelling performance of the product, the Box-benhnken combined test method was used to study the working parameters of the double screw extruder. The effects of screw speed, extrusion temperature and water content on the swelling rate, hardness, brittleness and water absorption of the expanded product were analyzed, and the determinants were optimized. The results showed that, based on the level of the significance, 1) factors affecting the expansion rate were ranked in material water content > expansion temperature > screw speed, 2) factors affecting hardness were ranked in material moisture content > screw speed > swelling temperature, 3) factors affecting brittleness were ranked in material moisture content > screw speed, 4) factors affecting water absorption were ranked in material moisture content > swelling temperature > screw speed. The optimal operating parameters were: screw speed 167.23 r/min, swelling temperature 151.68℃, material moisture content 16.83%. Under these conditions, the swelling rate, hardness, brittleness and water absorption of the product were increased by 4.04%, 18.61 N, -8.46 mm/cm2 and 313.86% respectively, compared to the traditional machine. Practical application of the optimized parameters revealed that the error between the optimized productivity and real productivity was less than 4%, with the maximum productivity being 165 kg/h. Compared with the existing equipment in the laboratory at School of Mechanical Engineering in Yangzhou University, the designed machine increased the swelling rate, brittleness, water adsorption and brittleness by 25.00%, 40.55% and 62.35% respectively, while reducing the hardness by 48.21%. Therefore, the design of this machine can provide relatively mature technical equipment for the development of mushroom swelling products. [ABSTRACT FROM AUTHOR]