Experimental and research on spiral squeezing shedding performance of fresh <italic>Camellia oleifera</italic> fruit

<bold>Objective</bold> In order to solve the problems of low dehulling rate and high seed breakage rate in the existing mechanical dehulling of <italic>Camellia oleifera</italic> fruit，this study designed a spiral extrusion dehulling machine for <italic>Camellia oleifera</italic> fresh fruit to improve its dehulling rate and reduce its seed breakage rate.This study conducted experiments and analysis on its dehulling performance. <bold>Method</bold> Based on the performance analysis of the fruit materials，a spiral extrusion type of <italic>Camellia oleifera</italic> fresh fruit huller was designed，and the mechanical analysis of the interaction process between the fresh fruit and the spiral extrusion hulling mechanism was conducted to determine the main influencing factors on the spiral extrusion hulling performance of the fresh fruit.Using the dehulling rate of the fruit and the seed breakage rate of the seeds as evaluation indicators，a single factor experimental method was adopted to determine the range of values for motor speed，dehulling clearance，and extrusion clearance.A three factor three-level orthogonal experiment was conducted with motor speed，dehulling clearance，and extrusion clearance as experimental factors.The dehulling rate of the fruit and the seed breakage rate of the seeds were used as evaluation indicators.The comprehensive weighted scoring method was used to optimize the parameters of the experimental factors and obtain the optimal parameter combination of each factor. <bold>Result</bold> The test showed that the main and secondary order of the influence of various factors on the evaluation index of <italic>Camellia oleifera</italic> fruit hulling rate and seed breaking rate of the seeds was hulling clearance，extrusion gap and motor speed.The optimal parameter combinations were as follows：motor speed 50 r/min，hulling gap 20 mm，extrusion gap 6 mm，<italic>Camellia</italic> fruit hulling rate 94.13%，and camellia seed crushing rate 3.15%. <bold>Conclusion</bold> The results show that the spiral extrusion type huller for fresh <italic>Camellia oleifer</italic>a fruit meets the expected design goals，and it can better complete the postharvest hulling processing requirements of <italic>Camellia oleifera</italic> fruit，which provides a test basis for the research and development and performance optimization of the whole machine in the future.