Calibration equations to estimate total and individual carotenoid concentrations by near-infrared reflectance spectroscopy (NIRS) in Solanum phureja potato germplasm were developed, validated and applied to the characterization of 152 S. phureja germplasm accessions. The cross, external and independent validation of the calibrations indicate that total carotenoids and zeaxanthin concentrations can be estimated by NIRS with high accuracy and that NIRS can be used to differentiate accessions with low, medium and high concentrations of violaxanthin, antheraxanthin, lutein or β-carotene. Significant variability was revealed for total and all individual carotenoids measured. Two varieties with significant zeaxanthin concentrations (above 1000 μg 100 g−1 FW) and a group of 43 accessions with relatively high β-carotene concentrations (above 10 μg 100 g−1 FW) were identified. The positive relation between total carotenoids and zeaxanthin as well as their negative relation with β-carotene reported for 23 accessions in the companion manuscript was upheld. The use of NIRS in estimating and characterizing a large germplasm collection has permitted the identification of accessions with high total carotenoids and zeaxanthin and relatively high β-carotene concentrations at low cost and in reduced time compared to HPLC. This can be applied to documentation of descriptive and potentially beneficial characteristics of potato genebank materials, the assessment of the food value of present varieties, and the selection of parents in a breeding program oriented to nutritional enhancement of potato.
Bonierbale, M.; Gruneberg, W.; Amoros, W.; Burgos, G.; Salas, E.; Porras, E.; zum Felde, T. Total and individual carotenoid profiles in Solanum phureja cultivated potatoes: II. Development and application of near-infrared reflectance spectroscopy (NIRS) calibrations for germplasm characterization. Journal of Food Composition and Analysis (2009) 22 (6) 509-516. [DOI: 10.1016/j.jfca.2008.08.009]
Total and individual carotenoid profiles in Solanum phureja cultivated potatoes: II. Development and application of near-infrared reflectance spectroscopy (NIRS) calibrations for germplasm characterization