不同干燥方式对复方赤灵芝提取物中5-羟甲基糠醛含量的影响

研究在干燥复方赤灵芝提取物时5-羟甲基糠醛的含量变化并探索合适干燥方案。该研究采用了喷雾干燥、真空干燥、红外线干燥、热泵干燥、热风干燥以及真空冷冻干燥对复方赤灵芝提取物进行处理，研究了不同工艺参数下5-HMF含量变化。喷雾干燥的进料速度、通气量逐渐增加时5-HMF含量先增加后减少；真空干燥下5-HMF含量随干燥温度、物料厚度的增加而增加，5-HMF含量、水分含量随真空度的增加而降低（P<0.05）；红外线、热泵及热风干燥下5-HMF含量随温度升高而增加。真空冷冻干燥后样品5-HMF含量为779.29 mg/kg，加工时间为50 h，耗时最长。在各优选方案下真空干燥所得样品5-HMF及水分含量最低为774.32 mg/kg、4.97%，加工时间17 h，耗时最短，样品呈黑褐色，质脆硬，不易复溶。因此，为保证有害物质5-HMF含量最低同时综合加工时间等因素，应优先考虑真空干燥方式，但还需采取进一步措施改善产品外观及复溶性。

Effects of Different Drying Methods on the Content of 5-Hydroxymethylfurfural in Ganoderma lucidum Extract Mixtures

Changes in the amount of 5-hydroxymethylfurfural (5-HMF), a harmful substance, in dried Ganoderma lucidum extract mixtures were investigated in order to find the most suitable drying method. The G. lucidum extract mixtures were processed using the following drying methods: spray, vacuum, infrared, heat pump, hot air, and vacuum freeze-drying. The 5-HMF content under different process parameters was measured. In the case of the spray drying method, the 5-HMF content increased initially and then decreased when the feed rate and air flow were gradually increased. In the vacuum drying method, the increase of drying temperature or material thickness led to an increase in 5-HMF content, and the 5-HMF and moisture content decreased as the vacuum degree increased (P<0.05). The 5-HMF content increased with the increase of temperature in the infrared, heat pump and hot air drying methods. The 5-HMF content of the samples after vacuum freeze-drying was 779.29 mg/kg, and the processing time, 50 h, was the longest of all the drying methods. The 5-HMF and moisture content of the sample obtained by vacuum drying under each optimal scheme were 774.32 mg/kg and 4.97%, respectively, and the processing time, 17 h, was the shortest of all the methods. However, the sample obtained from vacuum drying was dark brown, brittle, and hard, and was not easily redissolved. Considering the content of 5-HMF and drying time, as well as other factors, the vacuum drying method should be preferred, but further measures should be taken to improve the appearance and re-solubility of the product.