Brewer's spent grain valorization in fiber-enriched fresh egg pasta production: Modelling and optimization study

The aim of this work was to valorize brewer's spent grains (BSG) in the production of a fiber-enriched fresh egg pasta. To improve pasta structure, the addition of egg white powder (EWP) was also evaluated. An inscribed Central Composite Design was developed, ranging BSG from 3 to 25 000 g and EWP from 0 to 12 g/100 g. Highly significant models (p < 0.001) of different complexity were calculated for all the pasta quality parameters, except for thickness and weight increase during cooking. BSG addition significantly lowered average break strain of pasta with respect to a standard formulation produced without fiber (26 +/- 10% vs. 54 +/- 4%, for raw sheets; 25 +/- 8% vs. 54 +/- 1%, for cooked sheets). On the contrary, the addition of EWP improved mechanical properties of cooked pasta due to the tighter protein network developed by ovalbumin. With the highest EWP amount, break load (6.5 +/- 0.4 N) and strain (33 +/- 4%) of cooked pasta resulted significantly higher than in sample without EWP (1.4 +/- 0.1 N and 18 +/- 1%, respectively). Optimization of pasta quality by the desirability function demonstrated that BSG and EWP can be successfully exploited in the production of a fresh egg pasta source of fiber, thus contributing to a higher sustainability of the brewing process. (C) 2017 Elsevier Ltd. All rights reserved.