title: Estimation of cotyledon isoflavone abundance by a grey luminance-based model in variously hilum-coloured soybean varieties.
abstract: BACKGROUND
  The nutraceutical uses of soybean (Glycine max L. Merr.) have received increasing attention in recent years, due to the therapeutic effects of high seed isoflavone concentrations against heart disease, cancer and menopausal symptoms.
  
  
  RESULTS
  We found a close correlation between seed isoflavone abundance and hilum colour in a set of 17 contrasting soybean varieties. Image analysis of the hilum grey level pattern allowed us to identify a power model which approximates total cotyledon isoflavone concentrations (TCIC) at 65-71% by the normalised modal grey level. Higher TCIC levels were assigned to darker hilum varieties and vice versa within a variety-dependent response. Optimisation of the algorithm required correction for a few specific varieties falling in the intermediate 1.1-1.5 mg g(-1) TCIC range, which were over-estimated by the model, perhaps due to variations in hilar optical properties related to the geometric features of both hilum and seed.
  
  
  CONCLUSIONS
  In view of its easy, low-cost detection, seed hilum colour is a useful phenotypic trait in soybean for rapid evaluation of isoflavone abundance in food uses and for improving specific nutraceutical breeding programmes. © 2016 Society of Chemical Industry.
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and the Environment, University of Padova, Viale dell'Università 16, 35020 Legnaro, Padova, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Barion
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and the Environment, University of Padova, Viale dell'Università 16, 35020 Legnaro, Padova, Italy.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Mosca
authors.affiliation: Department of Agronomy, Food, Natural Resources, Animals and the Environment, University of Padova, Viale dell'Università 16, 35020 Legnaro, Padova, Italy.
authors.forename: Teofilo
authors.initials: T
authors.lastname: Vamerali
mesh_terms: D016000:Cluster Analysis; D003116:Color; D018548:Cotyledon / Q000737:chemistry; D007529:Isoflavones / Q000032:analysis*; D007558:Italy; D015999:Multivariate Analysis; D010940:Plant Proteins / Q000032:analysis; D012639:Seeds / Q000737:chemistry; D013025:Glycine max / Q000737:chemistry*
chemical_list: D007529:Isoflavones; D010940:Plant Proteins
keywords: hilum grey luminance; image analysis; isoflavone prediction; soybean varieties