Gleditsia triacanthos Galactomannans in Gluten-Free Formulation: Batter Rheology and Bread Quality

Gluten-free batters, in general, require the incorporation of agents to control their rheology; this role is commonly played by hydrocolloids. New natural sources of hydrocolloids are under permanent research. In this regard, the functional properties of the galactomannan extracted from the seed of Gleditsia triacanthos (Gledi) have been studied. In this work, we evaluated the incorporation of this hydrocolloid, alone and in combination with Xanthan gum, in gluten-free batters and bread and compared it with Guar gum. The incorporation of hydrocolloids increased the viscoelastic profile of the batters. Gledi addition at 0.5% and 1.25% increased the elastic modulus (G') by 200% and 1500%, respectively, and similar trends were observed when Gledi-Xanthan was used. These increases were more pronounced when Guar and Guar-Xanthan were used. The batters became firmer and more elastically resistant because of the addition of hydrocolloids; batters containing Gledi had lower values of these parameters than batters containing Gledi-Xanthan. The addition of Gledi at both doses significantly increased the volume of the bread compared to the control by about 12%, while when Xanthan gum was included, a decrease was observed, especially at higher doses (by about 12%). The increase in specific volume was accompanied by a decrease in initial crumb firmness and chewiness, and during storage, they were significantly reduced. Bread prepared with Guar gum and Guar-Xanthan gum combinations was also evaluated, and the trends observed were comparable to that of bread with Gledi gum and Gledi-Xanthan gum. The results showed that Gledi addition favors the production of bread of high technological quality.

Effect of sorghum flour properties on gluten-free sponge cake

As the demand for gluten-free products increases, the use of sorghum flour becomes a good alternative. Sponge cakes are consumed worldwide and suitable for formulations that could replace wheat flour. One of the most influential parameters on sponge cake quality is the flour particle size. In this study, we obtained and characterized different flours by milling white and brown sorghum grains and evaluated the influence of flour characteristics on batter properties and gluten-free sponge cake quality. Flours were produced by pearling, milling and sifting; and were characterized for flour composition, particle size distribution, damaged starch and water absorption. The structure, density, and viscosity of the batters; and specific volume and crumb properties of the sponge cake were evaluated. The results showed that flour composition, and properties were modified by the milling processes. Pasting viscosity increased as the particle size of the flours was reduced. Brown or white sorghum flour with smaller particle size produced high density and viscosity batters with small and homogeneous air bubbles distribution. Independently of the sorghum variety used, smaller particle size flour leads to sponge cakes of high volume and low firmness.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-021-05150-0.

Gluten-free sorghum pasta: starch digestibility and antioxidant capacity compared with commercial products

BACKGROUND

The development of new products with a focus on nutrition, rather than other technical aspects, is essential to improve the quality of celiac diets. Nutritional attributes of white and brown sorghum gluten-free pasta developed in a previous work were analyzed. The extent and kinetics of starch in vitro digestion, estimated glycemic index (eGI), potentially bioaccessible and dialyzable polyphenols, and antioxidant activity were evaluated and compared with commercial products.

RESULTS

Sorghum flour samples were used to obtain pasta with high protein (≈170 g kg^-1 ), dietary fiber (≈80 g kg^-1 ), polyphenols (2.6 g GA kg^-1 pasta), and antioxidant activity. This sorghum pasta showed slower starch in vitro digestion than the other gluten-free pasta, with a high level of protein hydrolysis (76%). The highest eGI was observed in a rice sample (69.8) followed by a corn-based pasta (66.4). White and brown sorghum gluten-free pasta showed 2.9 and 2.4 times, respectively, higher potentially bioaccessible polyphenol content compared to that in cooked pasta. No significant variation in antioxidant activity was found in sorghum pasta after digestion and around 48% and 36% of activity was detected in dialysate.

CONCLUSION

Both types of sorghum gluten-free pasta have demonstrated their nutritional value and represent a good potential alternative to current commercial pasta. © 2018 Society of Chemical Industry.

Wheat germ stabilization by infrared radiation

Wheat germ has an important enzymatic activity, being lipases the enzymes which cause the highest impact in the reduction of shelf life. The objective of this study was to evaluate the effects of infrared radiation on wheat germ stabilization in an attempt to extend the shelf life. The effects of treatment time, gap (sample distance to IR emitters) and infrared radiation intensity on wheat germ were analyzed through response surface methodology. Final moisture content, final temperature, color of germ and germ oil quality parameters: free fatty acid content changes and total tocopherol content were the responses evaluated using a Box-Behnken design. A combination of an infrared radiation intensity of 4800 W/m², a 3 min treatment and 0.2 m emitter-sample distance were the best processing condition to stabilize the wheat germ without significantly reduction of the tocopherol content. A confirmatory experiment was conducted with these optimal conditions, and the heat-treated and raw germ samples were stored for 90 days at room temperature in three layer packages to protect them against light and oxygen. The oil quality parameters indicated that the raw germ had a shelf-life of about 15 days, with the heat-treated wheat germ maintaining its quality for at least 90 days under these stored conditions.