Study on thin layer drying characteristics and color and quality of alfalfa

In order to study the effects of drying temperature and pretreatment methods on the drying characteristics and quality of alfalfa, the optimal drying process of alfalfa was determined by experimental research with greenness, total color difference, crude protein content, relative feed value and drying rate as indicators. Taking the drying temperature and pretreatment method as test variables, the hot air drying test and color difference analysis of alfalfa were carried out, and the quality of dried alfalfa was detected. The results showed that there was a positive correlation between drying rate and drying temperature, a negative correlation between alfalfa quality and drying temperature, and a negative correlation between alfalfa hay color and drying temperature; Under different pretreatment methods, flattening and bending treatment has the most significant effect on reducing the drying cycle, but has little effect on the quality. Taking the quality and color as the evaluation indexes, it is concluded that the best drying process is flattening and bending pretreatment and drying temperature of 70～80 ℃. The research results of this paper provide theoretical basis and technical reference for the drying and processing of alfalfa.