Abstract
Hydrogels (Hy) were obtained with a ternary system of proteins (pea (P) or soy isolate (S) 2%), guar (0.5%), and xanthan gums (0.5%) and were subjected to thermal treatment (70 °C/20 min or 85 °C/15 min, or not) prior to structure formation. The FTIR spectra of the hydrogels and the turbidity test (spectrophotometrically red at 600 nm) were used for studying protein-polysaccharide interactions. Amplitude sweeps (0.01-100%) and flow behavior tests (0.1-100 s(-1)) were conducted for structure analysis. Emulgels were obtained by emulsification of the Hy with 40% or 60% sunflower oil. The centrifugal stability and texture (TPA test) of the emulgels were assessed and SND_40% exhibited the highest hardness (5.30 ± 0.23 N). Based on the results, SND_40%, PND_40%, SD70_40%, and PD_70% were chosen as fat-replacing systems in biscuit formulation. The textural, color, and stability attributes of the reformulated samples were compared with a reference containing margarine. Increased hardness and fracturability were determined for the emulgel-based biscuits, while the color parameters were statistically similar to the reference. Thermal treatments applied to enhance protein-polysaccharide interactions increased the structural performances of some emulgels, while their application as fat-replacing systems should be further evaluated since no statistical differences were recorded in the sensory evaluation of the reference and reformulated biscuits. Emulgels with tuned technological properties have the potential to replace saturated fats in foods.