Effect of precooking process and drying methods on the physicochemical, microstructure, and sensory properties of spinach-enriched lasagna pasta

In this study, the effect of drying methods (hot-air and infrared (IR)) and precooking process on spinach-enriched lasagna pasta was investigated. Combination of precooking and IR drying process ended in a lasagna pasta with a shorter optimal cooking time (about 10.60 times) and higher water absorption (about 1.34 times) compared with samples produced with the conventional hot-air drying. Also, precooking and IR drying method had a significant effect on the color of final samples; according to the results of sensory evaluation, application of precooking-IR drying process resulted in a lasagna pasta with better color. X-ray diffractometry (XRD) results showed that the crystal structures of the non-precooked samples were completely different from the precooked ones. These findings were confirmed by scanning electron microscopy (SEM) images. Texture evaluation indicated that the drying methods influenced the hardness of products; in precooking-IR dried lasagna pasta, the hardness was 1.85 times higher than those produced with the conventional hot-air drying. Precooking the samples and drying them with IR improved the retention of phenolic compounds during cooking about 2.75 times higher than conventional samples. From a sensory point of view, the highest score of overall desirability was related to precooked lasagna pasta processed with IR dryer.