RESUMO
High dietary fibre cookies were manufactured from non-wheat (triticale, spelt and rye) flours with apple, beetroot and pumpkin pomace powders added as natural colourants. Cookies were characterized by nutritional composition, colour, texture and sensory profile and subjected to a 2-month shelf-life study. Additionally, an acceptability study was done to determine consumers' acceptance of cookies. Cookies prepared from rye flour and pumpkin pomace, as well as cookies prepared from spelt flour and beetroot pomace, can be labelled as 'high fibre' (dietary fibre content of 8.90% and 7.09%, respectively), while cookies prepared from triticale flour and apple pomace can be labelled as a 'source of fibre' (dietary fibre content of 4.50%). No obvious trend in the colour of cookies was observed after storage at room temperature and 40â °C, indicating the stability of natural colourants. Hardness decrease was observed in all samples after storage; however, the acceptability study showed that consumers prefer softer cookies. Sensory analysis showed that there were no signs of rancidity in samples after storage. Although triticale flour and apple pomace sample received the highest liking scores for appearance, odour and taste, all samples had liking ratings higher than 4 (indifferent) and can be further modified to satisfy consumers' demands.
RESUMO
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.
RESUMO
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.
