Evaluation of the optimal cooking time of rice by using FT-NIR spectroscopy and an electronic nose

FT-NIR spectroscopy and an electronic nose were used to evaluate the Optimal Cooking Time for milled, parboiled and quick-cooking rice and compared with gelatinization time and the suggested cooking time reported on package labels. Rice spectral data collected in reflectance mode using an FT-NIR spectrometer were transformed into second derivative for chemometric analysis. This technique detected the modifications induced by the hydration process during cooking and related to specific molecular groups. A electronic nose/commercial, consisting of metal oxide semiconductor and metal oxide semiconductor field effect transistor sensors, was used to follow the evolution of rice aromas during cooking. The results obtained by the techniques confirmed the feasibility of both methods to follow the rice profile during cooking and to evaluate the optimal cooking time, rapidly and objectively.