Effect of oil-seed pressing residue on bread colour and texture

Cold-pressing residue of walnut kernel (WKR) and brown linseed (BLR) was applied in wheat flour blends at 100:0, 95:5 and 90:10 ratios, of which enriched breads were baked, then stored for 3 days at ambient temperature. Colour parameters and firmness of bread crumb were measured daily. Bavarian rye-bread (BR) and wholemeal multigrain bread (WMMG) were used as competitive, marketable breads for comparing tests.

The studied oil-seed pressing residues (OSRs) resulted brown colour with different characteristics, depending both on the type of OSR and in comparison with marketed breads, too. The type and the ratio of OSR applied had no influence on the varying of crumb texture (P = 0.107). WKR and BLR enrichment provided stable texture for breads with a 3-day shelf-life, independently from their addition ratio. BLR resulted in softer crumb than WKR; however, this difference was considered to be negligible (P = 0.128). The WKR- and BLR-enriched breads stayed significantly softer at the end of storage time than the marketed breads (P = 0.000). Our results indicate that competitive bakery goods can be produced using oil-seed pressing residue/wheat flour blends.