A novel rice-based snack enriched with chicory root flour (CRF) was developed by twin-screw extrusion. Chicory (Cichorium intybus L.) is one of the promising medicinal plants for the development of innovative food and may be considered a functional food ingredient. Central composite design (CCD) was employed to generate snack formulations by varying feed moisture (M, 16.3–22.5%), screw speed (SS, 500–900 rpm) and CRF content (20–40%). The optimization according to artificial neural network modeling and a genetic algorithm was applied to define optimal process conditions (17.6% moisture, 820 rpm and 24.1% of CRF) for obtaining the product with the highest expansion (3.34), crispiness (3.22 × 10⁻³), volume (2040 m³), degree of gelatinization (69.70%) and good color properties. Bulk density (110.33 g/L), density (250 kg/m³), and hardness (98.74 N) resulted in low values for the optimal sample. The descriptive sensory analysis evaluated low hardness and bitterness, with high crispiness for the optimal extrudate. This study points to the possibility of a novel chicory enriched extrudate production with desirable physicochemical and sensory properties.

This study aimed to investigate the impact of chicory root addition (20–40%) and extrusion conditions (moisture content from 16.3 to 22.5%, and screw speed from 500 to 900 rpm) on bioactive compounds content (inulin, sesquiterpene lactones, and polyphenols) of gluten-free rice snacks. Chicory root is considered a potential carrier of food bioactives, while extrusion may produce a wide range of functional snack products. The mineral profiles were determined in all of the obtained extrudates in terms of Na, K, Ca, Mg, Fe, Mn, Zn, and Cu contents, while antioxidative activity was established through reducing capacity, DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) tests. Chicory root addition contributed to the improvement of bioactive compounds and mineral contents, as well as antioxidative activities in all of the investigated extrudates in comparison to the pure-rice control sample. An increase in moisture content raised sesquiterpene lactones and minerals, while high screw speeds positively affected polyphenols content. The achieved results showed the important impact of the extrusion conditions on the investigated parameters and promoted chicory root as an attractive food ingredient in gluten-free snack products with high bioactive value.

This study was carried out in order to evaluate the effect of extrusion conditions on the physico-chemical properties of corn grits-raspberry seeds snacks. The raspberry seeds were chosen to fortify the corn-based snack due to their richness in ellagic acid, a natural phenol antioxidant which has a beneficial effect on human health. Extrudates were prepared using a laboratory single-screw extruder, operated at different conditions. Box-Behnken experimental design was used to evaluate the impact of processing variables: moisture content (18-25%), temperature of extrusion (100-200 °C) and content of raspberry seeds (0-20%) on expansion index, hardness and ellagic acid content. Snack with the highest expansion (2.15) was obtained under 18% moisture, 150 °C temperature and 0% of raspberry seeds content. The highest content of ellagic acid (609.54 mg/kg) was reported in the samples with 20% of raspberry seeds, 100 °C temperature and 21.5% moisture. Extrudates obtained under conditions of 0% raspberry seeds, 100 °C temperature and 21.5% moisture showed the highest hardness value (53.34 kg). It was concluded that changing one or more parameters in the extrusion process can significantly affect the characteristics of the obtained product, and that raspberry seeds have a great potential in food fortification.