Research on the drying of the Siitake Mushroom for the purpose of the high quality

利用远红外加热对香菇进行干燥，以提高香菇的品质。研究结果如下：1)考察了远红外干燥与渗透脱水相结合的附加值。预期和实现的好处是稍微缩短干燥时间，减少收缩率，提高最终孔隙率，改善再水化特性，产品变形小。在45℃的中等温度下，用浓度为10 - 20%（w/w）的盐溶液对蘑菇进行渗透处理，可去除总有效水分的20%，盐增益高达0.5g /克初始干物质。2)利用远红外加热器对香菇的干燥特性进行了研究。研究了辐射强度、入口风速和相对湿度等参数对湿度和温度变化的影响。产品的干燥速度取决于辐射…更多的是强度水平。对香菇进行FIR干燥，发现其干燥速率呈下降趋势。风速的增大对干燥速度有不利影响。在较高的速度下，干燥率低是由于加热器表面的冷却作用导致温度降低。空气相对湿度对冷杉干菇没有影响。当辐射功率输入为0.17W/cm^2时，干燥速率比对流条件下提高50%。在较低的辐射功率输入下，蘑菇的收缩率高，复水化电位高，品质好。3)对一种远红外辐射源干燥产品的能量效率进行了研究，以确定能达到最高效率水平的能量输入。利用实验结果建立了预测干燥时间对产品含水率影响的简单数学模型，并对干燥效率进行了研究。当能量输入为0.17W/cm^2时，干燥效率最高。少

This study concerns on the quality improvement of shiitake mushroom by drying it using the far infrared heater. Results got from this research are as follows;1)The added value of far infrared drying combined with osmotic dehydration is investigated. Benefits expected and achieved from are a slightly reduced drying time, reduced shrinkage, higher final porosity and improved rehydration characteristics, small deformation of product. An osmotic treatment of mushrooms with a salt solution of 10 up till 20%(w/w) concentration at moderate temperature up to 45℃ gives a removal of 20% of the total available moisture and a salt gain up to 0.5g salt/gram initial dry matter.2)Drying experiments were carried out a using a far infrared heater to examine the drying characteristics of shiitake mushroom. The effect of several parameters e.g.radiation intensity, inlet air velocity and relative humidity on moisture and temperature history are present. Drying rate of products are dependent on the radiati … More on intensity level. FIR drying of mushroom was found a falling rate process. Increasing of air velocity was found to have a negative effect on the drying rate. Low drying rate at higher velocity was attributed to decreased temperature due to the cooling effect on the heater surface. Air relative humidity has no influence on FIR drying mushroom. With 0.17W/cm^2 radiant power input, the drying rate was 50% higher than under the convection. There was a higher shrinkage with a concomitant higher rehydration potential and superior quality of mushroom at lower radiant power input.3)A study of the energy efficiencies in the drying of products from one source of far infrared radiation was carried out to determine the energy input at which the highest level of efficiency would be attained. The experimental results were used not only to formulate a simple mathematical model for the prediction of moisture content of products as a function of drying time but also to study the dryer efficiencies. At 0.17W/cm^2 energy input, the highest drying efficiencies were attained. Less