Effects Of Different Production Modes On Quality Of Bletilla Striata

Bletilla striata(Thunb.)Reixchb.f.is a perennial herb of the orchid family.Its dry tuber is used as a medical material.This paper conducts preliminary research on the effects of light quality,harvesting period and drying method on B.striata.The aim of this study is to realize the initial regulation of the quality of B.striata.The research results are as follows:First,the effects of light quality on the morphological traits,antioxidant enzyme(superoxide dismutase,catalase,and peroxidase)activities,photosynthetic pigments content,and bioactive compounds(polysaccharides,phenols,and militarine)content in B.striata were investigated.Compared with the natural light-treated control group,the blue film treatment can significantly promote the growth of B.striata aerial parts,and can increase the total phenol and militarine content in B.striata tuber without affecting the accumulation of B.striata polysaccharide.Next,the effects of harvest period on the bioactive compounds(phenols,militarine,and polysaccharides)content of B.striata were determined.Comparing the results of the four harvesting periods,it was found that with the delay of the harvesting period,the change trend of BSP was the first to decrease and then gradually stabilized.The content of total phenol and militarine in the B.striata tuber collected on September 23 was higher.Lateral buds on the tuber of B.striata grew significantly.There was no significant change in fresh weight and drying rate.Under the premise of comprehensive consideration of B.striata quality and yield,the results show that it is more reasonable to harvest B.striata in late September.Finally,the effects of different drying methods on the appearance and bioactive compounds of B.striata were studied.Comparing the treatments of five different drying methods(HAD,IRD,MD,VD,VFD),it was found that shape and color of B.striata tuber were the best by vacuum freezing drying.Compared with hot air drying,the content of B.striata polysaccharide in infrared drying and vacuum freezing drying increased by 17.03% and 7.66%,respectively.The polysaccharide was seriously lost by microwave drying.The content of militarine in freeze-dried and infrared-dried samples increased by 15.71% and 9.66%,respectively.The total phenolic content in vacuum drying and vacuum freeze drying increased by 22.72% and 4.87%,respectively.In general,B.striata tuber is better in appearance and active ingredients content by vacuum freeze drying.