The objective of this work was to study the changes in sensory properties of biscuits when using new oil/hydrocolloid systems and/or when reducing fat to diminish saturated fatty acids content. Free Choice Profile (FCP) combined with the Repertory Grid (RG) method was used to determine the differences perceived by naive consumers at different stages of the eating process. Fourteen biscuits containing different types of fat (five oil/hydrocolloid systems and two conventional shortenings) were prepared at two fat levels (15.6% and 10.6%) and compared with two control biscuits prepared with the two conventional shortenings at 18% fat level. Sensory characteristics of biscuits were evaluated by consumers (n = 28) using their own set of descriptors. Generalized Procrustes Analysis (GPA) was applied to the data to determine differences perceived during each stage (first bite, during chewing, and during bolus aggregation/swallowing). Consumers agreed in using hardness to describe the differences among biscuits perceived at first bite. During chewing differences in other texture attributes and the main flavours in biscuits were found by some consumers. During the last eating period, consumers perceived clear differences in these main flavours but also in some other flavour notes. A substantial reduction in the fat content (10.6% fat) resulted in biscuits that were considerably harder and drier and had less flavour than the control ones (18% fat). A less drastic fat reduction (15.6% fat) made it possible to prepare biscuits which retained similar sensory properties to those of the controls. The biscuits prepared with either olive oil or sunflower oil and xanthan gum differed the most from the biscuits made with shortenings. The biscuits formulated with either olive oil or sunflower oil and HPMC had the closest sensory properties to the shortening biscuits. The sunflower oil/HPMC systems seemed to be the most suitable system for obtaining biscuits with a healthier fatty acid profile.

The authors have received financial support from the Spanish Ministry of Science and Innovation (AGL 2012-36753-C02-01 and Tarrega's contract within the Juan de la Cierva Programme). The authors also wish to thank The Dow Chemical Co. (Michigan, USA); Cargill, (Martorell, Spain) and Lucta S.A. (Barcelona, Spain) for providing free samples of the ingredients and to Gabriela van Beest for her collaboration in the experimental work.