|LANDRY, ERIK - Washington State University|
Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/18/2016
Publication Date: 5/24/2016
Citation: Landry, E., Fuchs, S., Hu, J. 2016. Carbohydrate composition of mature and immature faba bean (Vicia faba L.) seeds from diverse origins. Journal of the American Society for Horticultural Science. 50:55-60.
Interpretive Summary: Faba bean is an important specialty crop for certain immigrant and ethnic groups, and is grown nationwide as a vegetable, a grain for food and a cover crop by small and medium-scale farmers and by individual home gardeners. There is a great variation of seed size for this species and some researchers even proposed to classify the varieties to different subspecies based on seed sizes. In practice, three classes are recognized, namely, large-, medium- and small-seeded. However, there is no detail study on the low molecular weight carbohydrate (LMWC), including glucose, fructose, and sucrose (GFS) and raffinose, stachyose, and verbascose (RFO- raffinose family oligosaccharides) in faba bean with respect to seed sizes. LMWCs not only affect the product taste, one important quality trait, but also have potential health benefit to consumers. This research project analyzed the LMWC of 40 faba bean genotypes by high-performance liquid chromatography and obtained useful information for future faba bean quality improvement.
Technical Abstract: Faba bean (Vicia faba L.) is a valuable pulse crop for human consumption. The low molecular weight carbohydrates (LMWC): glucose, fructose, sucrose (GFS), raffinose, stachyose, and verbascose (RFO- raffinose family oligosaccharides) in faba bean seeds are significant components of human nutrition and taste. This study was conducted to quantify LMWCs in a diverse collection of faba bean. The LMWCs of mature and immature seed from 40 faba bean entries with a broad range in seed sizes (26.2-172 g 100 seed-1 DW) were analyzed by HPLC. Across all entries, there was considerable range in GFS and RFO content. On a dry weight basis, sucrose was the predominant constituent in immature cotyledons (12.9%) and seed coats (8.3%) and ranged from 5.9 to 22.6% for cotyledons and 6.7 to 16.7% for seed coats, while total RFO averaged <1%. In mature seeds, however, sucrose averaged half (2.4%) of the mean RFO content (4.3%) and ranged from 2.5 to 7.5%. For all entries, the rank order of immature seed GFS was not necessarily predictive of mature seed GFS. A moderate correlation was found between seed size and total GFS and RFO content of mature seeds, indicating the selection for large-seeded genotypes could indirectly increase LMWC concentration.