Effects of Xanthan Gum, Lambda-Carrageenan and Psyllium Husk on the Physical Characteristics and Glycaemic Potency of White Bread

Textural enhancement and glycemic potency reduction of sugarcane fiber-incorporated white bread with ascorbic acid and xanthan gum

In this study, ascorbic acid (0.02 % w/w), xanthan (0.75 % or 1.5 % w/w), and their combination have been added into sugarcane fiber (SCF) incorporated (5 % or 10 % w/w) wheat flour-based white breads. The effects of different additives on the physical characteristics, and the in-vitro and in-vivo glycemic potency of breads were evaluated. Addition of xanthan alone and the combination of additives reduced hardness and increased specific volume. SEM images showed that xanthan caused larger, more uneven holes in breadcrumbs due to xanthan's high elasticity and viscosity. FTIR spectrum indicated that the combination of SCF, xanthan, and ascorbic acid resulted in higher β-turn, lower α-helix protein structures, and lower ratios of α-helix/β-sheet, indicating a more flexible gluten structure formed. In-vitro digestibility results suggested that all SCF-incorporated breads had a lower glycemic index (GI) value than reference. Samples with 0.02 % (w/w) ascorbic acid and 1.5 % (w/w) xanthan reported the lowest in-vitro and in-vivo GI values.

Psyllium husk gel used as an alternative and more sustainable scalding technology for wheat bread quality improvement and acrylamide reduction

This study aimed at evaluating the influence of different amounts (5, 10, 15, 20, and 25%) of psyllium husk gel (PHG) on wheat bread (WB) characteristics - chiefly, overall acceptability (OA), porosity, specific volume (v), mass loss after baking (ML), shape retention coefficient, crust and crumb color coordinates, bread crumb hardness during storage, saccharides content, and acrylamide (AA) concentration. PHG was prepared by mixing 100 g of psyllium husk powder with 800 mL of warm water. It was established that the amount of psyllium husk gel is a significant factor in dough redness (a*) (p < 0.001). A moderate positive correlation (r) was found between acrylamide content in wheat bread and maltose concentration in dough (r = 0.567). The psyllium husk gel increased the overall acceptability and specific volume of wheat bread. Wheat bread porosity showed a moderate positive correlation with mass loss after baking (r = 0.567) and a strong positive correlation with texture hardness (r = 0.664). Lower acrylamide content was obtained in wheat bread prepared with 5, 10, 15, 20, and 25% of psyllium husk gel (1.53, 2.34, 3.80, 2.69, and 3.62 times lower than the control wheat bread, respectively). Acrylamide content showed a strong positive correlation with the porosity of wheat bread (r = 0.672), with crust brightness (L*), and yellowness/blueness (b*) coordinates, as well as with crumb brightness, redness, and yellowness coordinates. Overall, psyllium husk gel hydrocolloids reduced acrylamide formation in wheat bread and can be recommended for the quality improvement of wheat bread.

The effect of psyllium fiber on the in vitro starch digestion of steamed and roasted wheat based dough

This study aimed to determine how the addition of psyllium fiber to steamed and roasted wheat-based flat dough pieces affected the in vitro starch digestibility. Wheat flour was replaced with 10% psyllium fiber in the preparation of fiber-enriched dough samples. Two distinct methods of heating were utilised: steaming (100 °C, 2 min & 10 min) and roasting (100 °C, 2 min & 250 °C, 2 min). Rapidly digestible starch (RDS) fractions reduced significantly in both steamed and roasted samples, whereas slowly digestible starch (SDS) fractions increased significantly only in samples roasted at 100 °C and steamed for 2 min. The roasted samples had a lower RDS fraction than the steamed samples only when fiber was added. This study demonstrated the effect of processing method, duration, temperature, formed structure, matrix and the addition of psyllium fiber on in vitro starch digestion by altering starch gelatinization, gluten network, and consequently enzyme access to substrates.