Absrtact: Aiming at the problem of non-uniform heating of longan raw materials and excessive microwave drying rate and local overheating, the method of combining intermittent microwave with variable power microwave was adopted to dry longan. The changes of moisture ratio and drying rate of longan pulp during vacuum microwave drying were analyzed from three aspects: microwave drying equipment, vacuum degree and loading capacity, and a thin layer fitting model was established. The orthogonal test of power density, vacuum degree and loading capacity was established to optimize the intermittent vacuum microwave drying process of longan by taking color, total phenol content and rehydration as the evaluation indexes.
Key words: longan microwave drying; intermittent vacuum microwave drying; kinetics; nutritional quality
Longan is a famous tropical and subtropical fruit in China. As the origin country of longan, China accounts for 73.6% of the world’s planting area and 59.7% of the world’s output. Longan pulp is rich in sugar, polyphenols and other nutrients and active substances. As early as in the Compendium of Materia Medica, Longan has been recorded as a good source of resources. Modern medicine has also proved that Longan has anti-aging, immune enhancement and other effects, and is a good product for tonifying qi and blood.
没有评论:
发表评论