Tiger nut powder as ingredient for obtaining gluten free foods based on noodle processing and extrusion technology

Resumen

Tiger nut (Cyperus esculentus L.) is a sweet tuber mostly cultivated in Eastern Spain (Valencia) and in west Africa. Its nutritional profile stands out for the high fiber and unsaturated fat content; moreover, the moderate protein amount might make it suitable for the nutritional enrichment of gluten free foods. The objective of this thesis was to extend the applications of tiger nut as gluten free (GF) ingredient in noodles making and snacks. The study of marketed GF pasta revealed the nutritional inadequacy and lower cooking performances compared with their gluten containing homologous. The quantification of furosine content was handy for a better understanding of the heat damage caused during the production process. At this point, tiger nut flour was utilized for the design of gluten free noodles. The effect on noodles physicochemical characteristics leaded by different hydrocolloids (guar gum, xanthan gum, inulin and carboxymethyl cellulose) and by differing hydration levels revealed the importance in the selection of the most appropriate strengthening agent. Specifically, samples with 0.5% xanthan gum and adjusted hydration level exhibited the best cooking behavior and high final firmness. Owing to the growing extruded snacks success, tiger nut flour was blended with rice and soluble fiber to evaluate its technological adequacy for the extrusion-cooking process. Apparent viscosity, structural and surface characteristics of the gluten free snacks were deeply influenced by tiger nut addition. An improving of the nutritional profile, total soluble phenolics content and the total antioxidant capacity were found in the samples with tiger nut. Overall, it was possible to obtain GF foods containing tiger nut powder by applying different processing alternatives.