Evaluation of different processing modes for postharvest Poria cocos

Abstract: In order to optimize the Poria cocos processing technology and improve the production quality, this paper divided the Poria cocos post-harvest processes into 4 parts: pretreatment, peeling, cutting, and drying. Based on the survey research, the processing technology of Poria cocos was summarized to 2 categories: decentralized processing mode (DPM) and enterprise processing mode (EPM). The paper put forward the improved processing mode (IPM) on the basis of the optimization of the pretreatment and the drying process. Some experiment had been carried out in the practical producing environment to evaluate these 3 processing routes. This research performed the collection and calculation of data in economy, efficiency and quality aspects. The economy indices included labor costs, raw material costs, energy costs, tools and equipment costs, profit and profit rate. The efficiency indices included pretreatment efficiency, efficiency of peeling, cutting efficiency, and drying efficiency. The quality indices included product appearance, rate of finished products and polysaccharide content. Last of all, this paper made a comprehensive evaluation of 3 different processing routes based on the 3 indices above. The results showed that: 1) IPM could optimize the cost structure, the proportion of the cost and the stability of the investment. The profit and returning rate of IPM, DPM and EPM were 1.91 yuan/kg and 18.73%, 1.4 yuan/kg and 14.23%, and 1.17 yuan/kg and 12.43% respectively. It showed that IPM had the highest profit and returning rate while EPM was the lowest. It also meant that IPM had a better executive value in economy. 2) The drying efficiency of the IPM was 2.95 times that of the hot air drying which was usually used by the EPM, and the IPM was 20.79 times that of the natural drying of the DPM. The result indicated that IPM could effectively improve the efficiency in the drying process and effectively reduce the drying time under the premise of ensuring the quality. It also meant that IPM could avoid the adverse effects (such as mildew) caused by climate change through the timely processing of Poria cocos. 3) The scores ranking of 3 different processing routes in appearance of the products from high to low was DPM (score of 91), IPM (score of 87) and EPM (score of 75). The finished products of DPM and IPM showed a good appearance with flat, white surface and hard texture. In contrast, the surface of EPM finished product was rough, irregular, uneven and spongy. 4) Finished product rate and polysaccharide content by DPM, EPM and IPM were 40.28% and 34.69 mg/g, 39.23% and 27.09 mg/g, and 44.05% and 34.79 mg/g respectively. The consequence showed that IPM could increase the rate of finished product and the polysaccharide content. Moreover, the joint application of transpiration with pulsed vacuum drying technology could effectively ensure the quality of Poria cocos. 5) The comprehensive evaluation results showed that the IPM was more suitable for the processing of Poria cocos. The research results can provide the theoretical guidance and technical support for the production and processing of Poria cocos.