Effect of drying methods on the texture properties and active ingredients in Longan flesh

In order to determine the best drying method of longan flesh, the effects of different drying method (microwave drying, blast drying,vacuum freeze-drying) on the texture characteristics and active ingredients were compared. The results show that different drying methods will increase the hardness, cohesion and chewiness of longan flesh, and decrease the viscosity and elasticity to varying degrees. For active substances, the content of flavonoids and polyphenols is the largest under vacuum freeze-drying, followed by microwave drying and blast drying, but the loss of vitamin C is the opposite. On the whole, vacuum freeze-drying does not cause shrinkage of the flesh, and maintains good hardness, cohesion, chewiness and active ingredients. Comprehensive texture characteristics and changes in active ingredients, vacuum freeze drying is more suitable for drying and processing longan flesh.