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.

Effect of partial substitution of wheat flour by quinoa (Chenopodium quinoa Willd.) and tarwi (Lupinus mutabilis Sweet) flours on dough and bread quality.

Bread is the main important food product worldwide. In this study, eleven bread formulations were developed by partial substitution of wheat flour with quinoa and tarwi flours, to evaluate the effect on the rheological and pasting properties of mixtures, as well as on the physicochemical and textural properties of the final product. Partial substitution with quinoa flour generated similar thermomechanical and textural properties in the dough, and similar bread technological characteristics related to the control bread (100% wheat). In the case of tarwi, the increase in the concentration of this legume showed a negative effect on the bread quality parameters (specific volume, crumb porosity, textural properties, etc.). A negative technological impact of high percentages of wheat flour substitution by the mixture of both Andean flours was found, but it was contrasted with a positive effect on nutritional quality, particularly evidenced by a high content of proteins and dietary fiber. An optimal formulation considering technological and nutritional quality was obtained, presenting the maximum analyzed substitution level (13.35% quinoa flour and 6.65% tarwi flour). This study showed that these Andean grains are suitable for developing bread of good technological quality and improved nutritional profile, adding value to these underused ancestral flours.

Effects of the intake of white wheat bread added with garlic and resistant starch: action on calcium bioavailability and metabolic parameters of growing Wistar rats.

Wheat bread is a widely consumed food and is suitable for the introduction of functional ingredients. The aim of this work was to study the effects of bread with garlic and resistant starch as a fiber source on physiological, metabolic, and functional parameters using an in vivo Wistar rat model. Rats were fed with three diets: a control diet prepared according to the American Institute of Nutrition (C), and two semisynthetic diets containing wheat bread (B) and wheat bread with garlic, resistant starch and calcium citrate (BGR). Fresh feces were weighed and lactobacilli (L) and Enterobacteriaceae (E) were analyzed at different times: 1, 20, 45 and 60 days. The pH of the caecal content was recorded and at the end of the study changes in the bone mineral density of total skeleton (ts BMD), femur (F-BMD), spine (S-BMD) and tibia (T-BMD) were determined. Lipoprotein profile was assessed, atherogenic indexes were calculated and malonaldehyde content was measured in the serum and liver. In relation to gut microbiota, the BGR group showed an increase in the L/E ratio with respect to the other groups which was correlated with a lower cecal pH. Besides, the BGR group presented lower weight and a more favourable metabolic profile. In relation to bone measurements, the BGR group presented higher values of ts BMC, ts BMD, F-BMD, and T-BMD than the B group. Thus, bread with resistant starch, garlic and calcium citrate showed a prebiotic effect increasing calcium bioavailability and deposition in bones, compared with wheat bread. The observed beneficial health effects allow us to consider the design of healthier breads.