Textural attributes of commercial biscuits. Effect of relative humidity on their quality

Two commercial biscuits of semi-sweet type, 'Marie' and 'Petit Beurre' were used for investigating: (i) their texture variability as a function of the location and the side of puncturing and (ii) the influence of storage under different relative humidity on their texture, porosity and colour. Significant texture differences were found as a function of the location of puncturing (centre or periphery of biscuit area), as well as between the upper and the opposite side of a biscuit. At small relative humidity changes (11-32%) a distinct relationship between texture and moisture content was not noticed. In 'Petit Beurre' at a(w) 0.32 a peak was observed in the puncture force values. In both biscuits porosity increased with their moisture content, accompanied by an area expansion. Significant differences in colour were mainly noticed between the upper and opposite side of the biscuits. Colour was less influenced by relative humidity changes.