36E-90 |
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Y. HALIM1, L. Rodriguez-Saona1, S. J. Schwartz1, and D. Francis2. (1) Dept. of Food Science & Technology, Ohio State Univ., 2015 Fyffe Ct., 110 Parker Food Science Bldg., Columbus, OH 43210-1007, (2) Dept. of Horticulture & Crop Science, Ohio State Univ., Ohio Agricultural Research & Development Center, 1680 Madison Ave., 210 Williams Hall, Wooster, OH 44691-4114 Lycopene, a carotenoid with antioxidant properties, imparts the red pigment in some fruits and vegetables. Since lycopene is a phytonutrient, tomato breeders want to maximize lycopene content in breeding lines, and the industry wants to minimize loss during processing. Development of tomato varieties with increased lycopene is possible, but efficient selection requires the ability to measure lycopene content in thousands of samples. Current methods to assay lycopene are time consuming, expensive, and use hazardous organic solvents. Thus, simple, accurate and inexpensive assays are desirable for developing analytical methods for the detection of lycopene. The aim of this study was to develop simple and fast protocol for the accurate, reproducible and sensitive quantification of lycopene in tomatoes and tomato-based products using infrared spectroscopy combined with multivariate techniques. Attenuated total reflectance (ATR) infrared spectroscopic was used to quantify lycopene content in tomatoes. Twenty-six tomato breeding lines were obtained from OSU experimental station. Samples (tomato puree or lipid fraction) were placed in contact with a three-reflection diamond crystal plate. HPLC was used as reference method. Partial least squares regression (PLSR) was used to create calibration models that were cross-validated (leave-one-out approach) based on specific infrared spectral information and used to predict the content of these bioactive compounds. The infrared spectra showed a unique marker band at 967 cm-1 for lycopene. PLSR models predicted the lycopene content accurately with R2 >0.96 and standard error of prediction (SEP) <0.55 mg/L. Models generated from infrared spectra of lipid fraction allowed for the prediction of lycopene content in different matrices using a simple external calibration curve. The model was successfully applied to predict lycopene in tomato fruits and processed products. We have demonstrated that an ATR-IR protocol can be used for the rapid (~5 min), accurate and reliable quantification of lycopene in tomatoes with minimal sample preparation.
Session 36E, Fruit & Vegetable Products: General
2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana |