Abstract

CHOUPINA, Altino; LOPES-DA-SILVA, Fátima; SANTOS, Luís  and  BEIRAO-DA-COSTA, Luísa. Capacity of the chestnut flour for extruded production. Rev. de Ciências Agrárias [online]. 2020, vol.43, n.1, pp.278-297.  Epub Jan 06, 2020. ISSN 0871-018X.  https://doi.org/10.19084/rca.18554.

The objective of this work was to study the technological possibilities of producing extrudates based on chestnut flour. A single screw extruder was used. In a first step (test A), different mix ratios of chestnut and corn flours were analysed. The moisture content and the processing temperature were tested in the different mixtures. The extruded products were evaluated for the expansion rate, the viscosity profile obtained with amilograph and the texture estimated by the parameters breaking strength and energy using a texturometer. In a second step (test B), the composition of 100% chestnut flour was fixed and the screw speed was tested. The obtained extrudates were evaluated as previously mentioned. The experimental design thus considered three factors (X1- moisture content of the mixtures, X2- processing temperature and X3 - incorporation of chestnut flour in test A or screw speed in test B), with five levels per factor and six repetitions for the central point. Raw chestnut flour had a relatively low gelatinization temperature (59 °C) and gave pastes with high viscosity. Its starch had an amylose content of 43%, characterized by an amylose / amylopectin ratio of 0.75, which is higher than most of the cereal starches. The amylographic behavior of the mixtures and the texture characteristics of the extrudates showed that chestnut flour has potential to be used as an ingredient in the formulation of extruded cooked foods. Sensory analysis revealed significant acceptability by the panel elements for products processed at low moisture content and intermediate temperature.

Keywords : Extrusion; chestnut; starch; sensory analysis.

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