Influence of particle sizes and addition level of grape seeds on wheat flour dough rheological properties

Abstract

Particle size is an essential concept in flour milling which influences dough rheological properties and food product quality. The grape seeds flours (GSF) obtained by further grinding grape seeds vary in particle size and differ in chemical composition. Grape seeds selected from red wine pomace and wheat flour of a low extraction rate of 480 type were used in samples formulation. The objective of this work was to investigate the influence of different particle sizes and addition levels of grape seeds flour (GSF) on the rheological behavior of wheat flour dough. The rheological properties of wheat flour dough enriched with grape seeds flour were measured using empirical and fundamental test methods. The empirical dough rheological parameters were recorded during mixing, pasting and fermentation processes by using the Farinograph, Amylograph, Falling Number and Rheofermentometer devices. The results revealed changes in empirical rheological properties generated by the particle sizes and the addition level of GSF. Dough water absorption decreased with the increase of GSF addition level, influencing dough development time and stability. The falling number index showed a gradual decrease with the particle size decrease and addition level increase. GSF particle sizes and addition levels influenced mostly the Amylograph properties. The gas production and gas retention coefficient registered by Rheofermetomenter device were influenced by the GSF particle sizes and addition levels in different way. Fundamental dough rheological properties were investigated in linear viscoelastic range by using frequency sweep tests to assess the influence of particle sizes and addition level of GSF on storage modulus (G'), loss modulus (G'') and loss tangent (tan δ). The study highlights that the grape seeds fractions at different particle sizes change the dough rheological properties, allowing the use of grape seeds addition in bread-making products as an ingredient in white wheat flour.