Carotenoids concentration among maize genotypes measured by near infrared reflectance spectroscopy (NIRS) N. Berardo a, * , O.V. Brenna b , A. Amato a , P. Valoti a , V. Pisacane a , M. Motto a a Experimental Institute of Cereal Research, Maize-Section Bergamo, Italy, via Stezzano 24, I-24126 Bergamo, Italy b Department of Food Science and Microbiology, University of Milan, Italy Received 21 November 2003; accepted 5 March 2004 Abstract The objective of this study was to evaluate the carotenoid concentrations, by applying near infrared reflectance spectroscopy (NIRS) model developed by using HPLC data set, in samples of maize grain derived from 64 different genotypes. The results showed that the methods of analyses (HPLC vs. NIRS) were in good agreement, and their association (r 2 ) ranged from 0.82 for lutein to 0.94 for zeaxanthin. In addition, our results provided evidence that wide differences existed among kernel samples for all carotenoid components examined: violaxanthin, lutein, zeaxanthin, isolutein, cryptoxanthin and carotenes. Lutein and zeaxanthin, the prevalent carotenoids present in the maize kernels, ranged, respectively, from not detectable (Quarantino bianco) to 29.70 (Lo1010 Â Lo1058) and from 0.5 (Quarantino bianco) to 38.20 mg kg À 1 (Quarantino giallo). D 2004 Elsevier Ltd. All rights reserved. Keywords: Carotenoids; Near infrared reflectance spectroscopy; HPLC; Maize; Genotypes Industrial relevance: This paper reports on the application of the non-destructive near infrared reflectance spectroscopy (NIRS) in order to screen a large number of samples regarding their carotenoid content. This can be of significance in variety selection or in breeding programs attempting to achieve enriched carotenoid maize hybrids. 1. Introduction Maize is one of the most important agronomic crops in the world. Its grain provides food, feed, and a resource for many unique industrial and commercial products. Improving nutritional composition of the grain will pro- vide new opportunities to enhance the value of maize grain. Carotenoids are a notable example (Leath, 2003). These components are natural pigments that are essen- tial to microbial, plant, and animal life. Structurally, these pigments are terpenoids derived by condensation of prenyl pyrophosphates Fig. 1 (Palace, Khaper, Qin & Singal, 1999). The exact chemical structure of individual carote- noids is decisive for their biological properties because it determines how they interact with other molecules and integrates into membranes (Rouseff, Raley & Hofsomner, 1996). Moreover evidence is accumulating that carote- noids, acting as chemical scavengers, play an important role in human health by preventing degenerative diseases, including cancer (Langeseth, 1995). These components with unsubstituted h-ionone end groups are precursors of vitamin A. The industrial use of carotenoids involves their application for nutrient supplementation, pharmaceutical purposes, as food colorants, and animal feeds (Weber, 1987). In addition, lutein and zeaxanthin, the dominant carotenoids in maize kernels, are the essential components of the macular pigment of the eye (Beatty, Boulton, Henson, Koh & Murray, 1999). In recent years, HPLC methods were applied to deter- mine carotenoids in different foods (Weber, 1987; Minguez- Mosquera & Hornero-Me ´ndez, 1993; Edwards, Dexter, Sobering & Williams, 1996; Rouseff et al., 1996; Konings & Roomns, 1997; Togersen, Isaksson, Nilsen, Bakker & Hildrum, 1999; Buratti, Pellegrini, Brenna & Mannino, 2001); most of them used a diode array detector (DAD). All these methods require the previous extraction of the analyte from the matrix; therefore difficulties may arise with regard to their stability over the whole protocol. Carotenoids 1466-8564/$ - see front matter D 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.ifset.2004.03.001 * Corresponding author. Fax: +39-035-316054. E-mail address: berardo@iscbg.it (N. Berardo). www.elsevier.com/locate/ifset Innovative Food Science and Emerging Technologies 5 (2004) 393– 398