Effect of extruded wheat bran on volatile and physicochemical properties of bread during its shelf life

This study aims to extend the shelf life of bran bread and serve as a reference for future research on storage and preservation of bran bread after production. In this study, original bread made of refined wheat flour was used as a control, and texture analyzer, low-field nuclear magic resonance (LF-NMR), differential scanning calorimeter (DSC), X-ray diffractometer (XRD), and headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) were used to analyze changes in their volatile and physicochemical properties during storage. During storage, the moisture of bran bread crumb decreased by 11.17%, while the moisture of the original bread crumb decreased by 14.76%. All samples became harder and less springy, but the change rate of hardness, springiness were slower than those of the original bread. Amylopectin retrogradation was significantly slower in bran bread. T2 populations shifted toward shorter relaxation times during storage. Thirty-four typical target compounds were identified by HS-GC-IMS, mainly included ketones, alcohols, and esters compounds. After five days of storage, all breads produced a rancid aroma. This result indicated that addition of extruded bran could delay the staling of the bread.