Oscillatory Rheology and Creep-Recovery Behaviour of Grape Seed-Wheat Flour Dough: Effect of Grape Seed Particle Size, Variety and Addition Level

In the present study, the influence of grape seeds flour (GSF) addition on the physico-chemical and white wheat flour dough rheological properties were investigated. GSF of two grape varieties, white and red, was added at three particle sizes (L, M and S) and different addition levels (0, 3, 5, 7, 9%) to the white wheat flour. The fundamental rheological properties were investigated by applying oscillatory tests using a dynamic rheometer. The storage (G') and loss (G '') moduli in function of frequency and temperature respectively, were measured. Creep-recovery tests were also applied to evaluate grape peels-wheat flour dough behaviour. The results showed that the GSF incorporation increased protein content and alpha-amylase activity in composite flour with particle size decrease, affecting gelatization temperature. The changes in dough viscoelasticity depend on the particle size, addition level and grape variety, factors which affected dough capacity to deform. The effects of GSF from white grape were more pronounced compared to GSF from red grape variety. GSF addition exhibited an increase in values of both dynamic moduli, which was more pronounced for the white variety than for the red one. The knowledge of this information is useful in new products development, especially for bakery products manufactory.