Seasonal variations in nutritional components of green asparagus using the mother fern cultivation

Harvesting season for green asparagus can be extended by the use of the mother fern method and greenhouse cultivation. To evaluate seasonal variations in nutritional quality of green asparagus, the compositional profiles of fresh spears (Asparagus officialis L. cv. UC157 F1) harvested each month from March to October were compared in two locations of China using mother fern method. During the harvest season, dry matter content, soluble sugar, crude fiber, rutin and total soluble phenol in spears exhibited marked variation. Although there was no significant difference in total amino acid contents among most of months throughout the season, but quantitative changes in some specific amino acids occurred. Fresh spears harvested in warm season (from June to July) contained lower level of soluble sugars, dry matter, ascorbic acid and higher nitrate, crude fiber, total phenolics and rutin contents compared with those in cooler months. Asparagus harvested in spring accumulated relatively higher level of soluble sugar, carotenoid and chlorophyll contents than those in autumn, but total phenol and rutin contents were higher in autumn than in spring. The relationships between weather data and nutritional quality parameters of asparagus spear during harvest season were also discussed.