Study on the Suitable Harvest Period of Gastrodia elata Bl. in Tonghai Based on Principal Component Analysis

Purpose To provide theoretical support for the quality evaluation standard and the best harvesting time of Gastrodia elata in Tonghai.

Methods The contents of gastrodin, p-hydroxybenzyl alcohol, parishin A, parishin B, parishin C and parishin E of G. elata in five harvest periods in Tonghai were determined by HPLC. Combined with the yield, protein and polysaccharide content of G. elata, the weight of each index was calculated by principal component analysis (PCA), and the best harvest time of G. elata was obtained by comprehensive evaluation.

Results The yield of G. elata harvested in January and February was significant higher than that in other harvest periods. The total content of gastrodin and p-hydroxybenzoic acid harvested in February were significant higher than that in other harvest periods. The content of parishin harvested in December was significant higher than that in other harvest periods. The protein content harvested in October, November and January was significant higher than that in other harvest periods. The polysaccharide content harvested in December and January was significant higher than that in other harvest periods. PCA result showed that the weight of yield, parishin, and polysaccharide were higher than that of gastrodin and p-hydroxybenzyl alcohol, and the weight of protein was close to p-hydroxybenzyl alcohol. The highest comprehensive score of harvesting in December of the planting year was 0.603.

Conclusion The quality of G. elata harvested in December is the best in Tonghai, attention should be paid to the contents of parishin, polysaccharide and protein in the quality evaluation of G. elata.