New formulations of functional white sauces enriched with red sweet pepper: a rheological, microstructural and sensory study

Red sweet peppers are good sources of antioxidant compounds, such as fibre and carotenoids. Therefore, innovative products that may replace traditional ones, such as white sauces enriched with red sweet pepper, should be developed to improve their functionality. The aim of this work was to study the rheological behaviour, microstructure, syneresis, colour, sensory characteristics and consumer acceptability of new white sauces enriched with red sweet pepper. The results of the rheological studies (viscoelastic behaviour) showed that in the available frequency window all the sauces showed a predominance of the elastic modulus versus the viscous modulus. The effect of incorporating red pepper on the rheological properties depended upon the type of starch used. Microstructure of native starch sauces showed a complex matrix composed of protein and amylose and amylopectin leached from the granules that have been disintegrated during the sauce elaboration. Fat globules were homogenously dispersed and associated with the protein phase. Modified starch sauces showed more swollen starch granules compared with native starch sauces and a protein matrix stabilising the fat globules. All the sauces exhibited considerable intrinsic autofluorescence due to the presence of carotenoids from the red pepper. Consumers scored the modified starch sauces regardless of the starch concentrations based on their highest overall liking and found them beneficial for health. Therefore, new white sauces with high nutritional value, high acceptability, good rheological properties and stability against syneresis could be formulated using red pepper and modified starch.