Effect of chestnut flour supplementation on physico-chemical properties and oxidative stability of gluten-free biscuits during storage

In the present paper, the effect of different levels of chestnut flour (0, 500, 800, 1000 g/kg) in gluten-free biscuits' formulations was evaluated, during a storage of 60 days. Chestnut flour increased water binding capacity and decreased water absorption index of the gluten-free mix used as the basis of biscuits' recipe, leading also to a decrease of both viscous and elastic moduli as well as hardness of the formulated doughs up to 70% in comparison to control samples. At time 0 day, the highest chestnut flour contents (1000 and 800 g/kg) gave the highest hardness values of the biscuits; during storage all the formulations showed water content increase from about 26 to 35 g/kg. Correspondingly, also hardness values increased during storage while only the samples produced with 1000 g/kg chestnut flour remained constant in time. In addition, gluten-free biscuits produced with chestnut flour appeared darker (lower L* and higher a* and b* values) and with higher oxidative stability values, probably in relation to the antioxidants present in chestnut. Chestnut flour improved technological and organoleptic quality of the gluten-free biscuits. In particular, 500 g/kg chestnut flour replacement may be considered the best compromise between quality and storage stability.