title: Assaying Total Carotenoids in Flours of Corn and Sweetpotato by Laser Photoacoustic Spectroscopy.
abstract: This study describes the application of the laser photoacoustic spectroscopy (PAS) for quantification of total carotenoids (TC) in corn flours and sweetpotato flours. Overall, thirty-three different corn flours and nine sweetpotato flours were investigated. All PAS measurements were performed at room temperature using 488-nm argon laser radiation for excitation and mechanical modulation of 9 and 30 Hz. The measurements were repeated within a run and within several days or months. The UV-Vis spectrophotometry was used as the reference method. The concentration range that allows for the reliable analysis of TC spans a region from 1 to 40 mg kg(-1) for corn flours and from 9 to 40 mg kg(-1) for sweetpotato flours. In the case of sweetpotato flours, the quantification may extend even to 240 mg kg(-1) TC. The estimated detection limit values for TC in corn and sweetpotato flours were 0.1 and 0.3 mg kg(-1), respectively. The computed repeatability (n = 3-12) and intermediate precision (n = 6-28) RSD values at 9 and 30 Hz are comparable: 0.1-17.1% and 5.3-14.7% for corn flours as compared with 1.4-9.1% and 4.2-23.0% for sweetpotato flours. Our results show that PAS can be successfully used as a new analytical tool to simply and rapidly screen the flours for their nutritional potential based on the total carotenoid concentration.
authors.forename: Svjetlana
authors.initials: S
authors.lastname: Luterotti
authors.forename: Dane
authors.initials: D
authors.lastname: Bicanic
authors.forename: Kristina
authors.initials: K
authors.lastname: Kljak
authors.forename: Darko
authors.initials: D
authors.lastname: Grbesa
authors.forename: Eduardo San Martin
authors.initials: ES
authors.lastname: Martínez
authors.forename: Ruud
authors.initials: R
authors.lastname: Spruijt