Application of a Handheld Infrared Sensor for Monitoring the Mineral Fortification in Whole Grain Cornmeal

Abstract

The requirements for labeling and safe control of dosage during the production of fortified products in complex matrices require reliable, precise, and accurate concentration analysis. On-line or real-time spectroscopic methods can provide a valuable window into in-process food manufacturing to permit optimization of production rate and ensuring quality of food products. Our objective was to develop a real-time methodology for monitoring fortification of whole grain cornmeal throughout the industrial mixing process using a handheld infrared (IR) sensor. Whole grain cornmeal was fortified with a blend premix, containing zinc, iron, vitamin E, and calcium, at different levels (0.5-5.5%) and mixed for 30 min to ensure homogenous distribution of the fortificants. Real- time IR analysis was achieved by pressing an aliquot (0.1 g) onto an attenuated total reflectance diamond crystal of a portable handheld spectrometer and spectra were collected. Multivariate analysis was used to exam- ine the data collected for monitoring distribution unifor- mity. The handheld regression (partial least squares regression) model based on specific IR spectral informa- tion (1,200-900 cm −1 ) associated to phosphate ion stretching vibration bands showed strong correlation (coefficient of correlation for validation >0.96) and similar performance statistics (standard error of cross-validation= 0.4%) as models generated from spectra collected by a benchtop system. Given the greater simplicity, speed, versatility, ruggedness, and portability of the handheld system over the laboratory benchtop instrument, it can provide the food industry with real-time sensor to evaluate the fortification of whole grain cornmeal snack foods, enabling timely correction measures during manufacture.