Substitution of wheat starch with non‐wheat starches and cross‐linked waxy barley starch affects sensory properties and staling of Arabic bread

Abstract

Substitution of starch from barley, corn, oat, potato, rice or sorghum for prime wheat starch in the formulation of Arabic bread resulted in breads with signi®cantly (P`0.05) different textural attributes from regular wheat bread except for barley starch. Substitution of waxy barley starch (957 g kg À1 amylopectin) for wheat starch (279 g kg À1 amylopectin) resulted in bread that was not signi®cantly different from regular wheat bread when assessed in the fresh state. However, upon aging, the waxy barley starch-containing bread staled at a signi®cantly (P`0.05) faster rate than regular wheat bread. Breads made with waxy barley starch cross-linked with 50, 200 or 500 ppm phosphorus oxychloride showed higher enthalpy of melting (DH) upon aging and staled faster than the bread formulated with waxy barley starch. These ®ndings suggest that amylopectin retrogradation is one of the determinants of Arabic bread staling and that cross-linking promotes recrystallisation of amylopectin, possibly by keeping the polymer chains in close proximity. The rate of staling in breads formulated with cross-linked waxy barley starch decreased with increasing levels of cross-linking, possibly owing to restrictions in the degree of starch swelling.

Bread Staling: Updating the View

“…The use of modified starches for retarding staling has been suggested since the 1990s, for their ability to influence amylopectin crystallization (Inagaki and Seib ; Yook and others ; Toufeili and others ). Due to the fact, however, that other linear fractions of starch may affect retrogradation, an increased interest has been registered on cross‐linked starches, due to their ability to increase the gelatinization temperature, setback viscosity, and decrease the transition enthalpy of gelatinization (Zheng and others ; Woo and Seib ).…”

Gelatinization Properties and Bread Quality of Flours Substituted with Hydroxypropylated, Acetylated and Phosphorylated Cross-linked Tapioca Starches

“…Although we used chemically modified tapioca starch, the results that hydroxypropylated starch retarded bread staling and cross linked starch accelerated staling were very similar to previous results. 12,13) In this study, we revealed that acetylated tapioca starch accelerated bread staling as well as cross linked one. Several workers reported that higher amount ( 20% (w w)) of tapioca starch substitution deteriorates bread qualities.…”

“…Inagaki and Seib 12) and Toufeili et al . 13) reported that bread with cross linked barley starch accelerated bread firming during storage. Although we used chemically modified tapioca starch, the results that hydroxypropylated starch retarded bread staling and cross linked starch accelerated staling were very similar to previous results.…”

Use of Multivariate Analysis of MIR Spectra to Study Bread Staling

“…In order to improve its durability, many authors have studied the process of bread staling, 5,6 by means of different techniques: X-ray diffraction, 7,8 Nuclear Magnetic Resonance, 9,10 Differential Scanning Calorimetry, 1,4.11-15 texture measurements, 5,7,13,16 dynamic mechanical thermal analysis, 8 polarizedlight microscopy observations, 17 measurements of various types of mechanical and rheological parameters, 18 sometimes accompanied by sensory evaluation carried out by a group of panelists. 5,12,13 Among others, also middle and near infrared spectroscopy (MIR and NIR) have been used to study the bread staling process, 15,16,19,20 proving the effectiveness of these techniques to this aim. In particular, MIR seems to be valuable in following the molecular conformational changes, since the band shape reflects the degree of ordering that is present in the system, while NIR reflects both chemical and physical aspects, but mainly the changes of hydrogen bonding in the starch crystalline network.…”