Influence of protein source and polysaccharide structuring agents on water immobilisation and gel properties of fermented high-protein desserts.

Abstract

The influence of protein source and polysaccharide structuring agents on thermal behaviour, water immobilisation and gel properties of high-protein desserts was investigated. Desserts formulated with whey protein isolate or yeast protein and structured with furcellaran in the presence of inulin or maltodextrin were evaluated using differential scanning calorimetry, rheological measurements, Fourier transform infrared spectroscopy and texture analysis. Whey protein systems formed more elastic and deformation-resistant gels, exhibiting higher water-holding capacity (93.2-95.2%) and greater yield strain (4.35-4.53) than yeast protein systems (65.2-73.8% and 0.23-1.66, respectively). In contrast, yeast protein systems showed greater variation in freezable water enthalpy (114-251 J/g). Inulin reduced water activity (0.938-0.940) and promoted more cohesive matrices, whereas maltodextrin produced softer gels (hardness 0.06-0.08 N). Overall, protein source and polysaccharide composition significantly affected water organisation, thermal behaviour and gel properties of fermented high-protein desserts.