Rheological and Microstructural Characterization of Wheat Dough Formulated with High Levels of Resistant Starch

Modified celluloses improve the proofing performance and quality of bread made with a high content of resistant starch

BACKGROUND

Adding resistant starch (RS) to bread formulations is a promising way of increasing fiber content of white bread. However, the partial replacement of wheat flour (WF) by RS can lead to a decrease in technological quality. The objective of this study was to analyze the performance of hydroxypropylmethylcellulose and carboxymethylcellulose as improvers of wheat bread with a high level of replacement (30%) with maize RS. The levels of the modified celluloses were 1% and 1.5% (WF + RS basis), and a formulation without modified celluloses was used as control. Proofing time, loaf volume, crumb characteristics (porosity, texture), and bread staling parameters (hardness increase, moisture loss), among other attributes, were analyzed, and principal component analysis was applied to compare samples.

RESULTS

The use of both modified celluloses was effective in improving the quality of breads. Specific volume and crumb porosity were enhanced, particularly at the 1.5% level. Breads with modified celluloses also allowed a higher retention of water and a better preservation of mechanical properties during storage. The principal component analysis projection graph for the first two principal components showed that samples with modified celluloses were clustered by the level of hydrocolloid addition rather than by the type of hydrocolloid used, although all the samples with modified celluloses were close to each other and distant from the control sample without hydrocolloids.

CONCLUSION

The quality decrease resulting from the replacement of WF by a high level of RS can be greatly compensated by the use of structuring agents such as hydroxypropylmethylcellulose and carboxymethylcellulose. © 2022 Society of Chemical Industry.

Andean crops: kañiwa and tarwi flours used for the development of vegan gluten-free muffins

BACKGROUND

The flours of two Andean crops, tarwi (Lupinus mutabilis) and kañiwa (Chenopodium pallidicaule Aellen), present an excellent nutritional profile for inclusion in vegan gluten-free muffin formulations. In this study, the proximal composition and techno-functional properties of tarwi and kañiwa flours, and the technological quality of batters and muffins (potato starch-based) formulated with 50% of these flours were evaluated.

RESULTS

Andean flours have high protein, fiber, and fat content, and display high water and oil absorption. In premixes formulated with potato starch and Andean flours, a reduction in paste viscosity was observed due to starch dilution and lower water availability. Depending on their ability to interact with water, the batters formulated with these flours had a higher consistency. Confocal laser scanning micrographs showed that batters with Andean flours presented a complex matrix with dispersed starch granules surrounded by proteins and fiber fragments. Muffins made with Andean flours had a slightly lower specific volume than the control, but crumb hardness was not modified by tarwi flour (50%) and a mixture of tarwi (25%) and kañiwa (25%) flours. The intrinsic color of these flours modified crumb color, and their reducing sugar content also favored Maillard reactions in the crust. These color changes are desirable in gluten-free products because such products are frequently pale due to their high starch content.

CONCLUSIONS

This study showed that tarwi and kañiwa flours are suitable for developing vegan, gluten-free muffins of good technological quality and improved nutritional profile, adding value to these underutilized ancestral flours. © 2022 Society of Chemical Industry.

Composition and Physicochemical Characterization of Walnut Flour, a By-product of Oil Extraction

The by-product of walnut oil (Juglans regia L.) extraction is a press cake rich in polyunsaturated fatty acids and other bioactive compounds. From this cake, walnut flour is obtained by a milling process. The composition and a physicochemical characterization of walnut flour was performed: proximal composition, mineral content, and fatty acid and amino acid profiles were measured. Besides, antioxidant capacity and water and oil holding capacities were determined. Walnut flour has 55% of lipids with an optimum w6/w3 ratio, a good lysine/arginine ratio, and high levels of antioxidants that contribute to its oxidative stability, the estimated shelf life being 16 months. In regards to interaction with other ingredients, walnut flour retained 258 and 70% (w/w) of water and oil, respectively. Therefore, these results show that walnut flour is a good source of micro- and macronutrients, compared to flours commonly used in breadmaking. Also, walnut flour has good technofunctional properties and thus its incorporation could improve the nutritional and technological characteristics of new bakery products.