The role of sodium chloride in the sensory and physico-chemical properties of sweet biscuits

•Sensory tests revealed significant differences at salt reductions of 33% and above.•The structure of salt-reduced biscuits showed larger and more air cells.•Salt reduction has led to a decrease in water content and hardness of the biscuit.•Salt affects cereal proteins aggregation around flour particles and on bubble walls.•Salt reduction decreases the concentration of hydrophobic volatile in the headspace.