Density separation as a strategy to reduce the enzyme load of preharvest sprouted wheat and enhance its bread making quality

- NaCl solutions allow the separation of sound from severely sprouted wheat kernels.
- Lower density kernels displayed signs of protein and carbohydrate breakdown.
- Fractions with reduced enzyme activity were recovered from batches of sprouted wheat.
- Such fraction had improved FN value and dough and bread making properties.
- Density separation is a powerful tool to upgrade the quality of sprouted wheat.

As preharvest sprouting of wheat impairs its use in food applications, postharvest solutions for this problem are required. Due to the high kernel to kernel variability in enzyme activity in a batch of sprouted wheat, the potential of eliminating severely sprouted kernels based on density differences in NaCl solutions was evaluated. Compared to higher density kernels, lower density kernels displayed higher α-amylase, endoxylanase, and peptidase activities as well as signs of (incipient) protein, β-glucan and arabinoxylan breakdown. By discarding lower density kernels of mildly and severely sprouted wheat batches (11% and 16%, respectively), density separation increased flour FN of the batch from 280 to 345 s and from 135 to 170 s and increased RVA viscosity. This in turn improved dough handling, bread crumb texture and crust color. These data indicate that density separation is a powerful technique to increase the quality of a batch of sprouted wheat.